[0001] The present invention relates to a device for operating a contact roller in a plant
for monoaxially or biaxially stretching polymer films. In particular, the invention
relates to a device allowing a variable positioning of a contact roller in relation
to a polymer film take-up roller outer surface. Furthermore, the invention relates
to a process for operating a contact roller in a plant for biaxially stretching polymer
films by using the device of the invention. Particularly, the invention relates to
a process allowing a variable positioning of a contact roller in relation to a polymer
film take-up roller outer surface.
[0002] The first step of an overall process of fabricating biaxially oriented films comprising
polymer materials is an extrusion, through a die, of a film of a molten polymer onto
a roll ("chill roll") the surface of which is kept at a temperature below the glass
transition temperature of the respective polymer. The roll surface quenches the polymer
into an amorphous state.
[0003] A subsequent step of said process comprises steps of stretching the film previously
generated by well-known methods in the longitudinal (machine) direction and/or in
the transverse direction, the latter being a stretching step in a direction perpendicular
to the machine direction, commonly. These stretching steps may be performed alone
or may be performed one after the other or may be performed simultaneously. In the
case of sequential stretching, the stretching process itself is carried out by two
machine units, usually first in the longitudinal/machine direction (i. e. in the direction
of the travelling path of the polymer film on the stretching device) and then in the
transverse direction. In the case of simultaneous stretching, a stretching action
in the longitudinal (machine) direction and transverse direction needs the simultaneous
application of stretching forces to the film material in two directions (usually perpendicular
to each other), while the film is moving with high speed along a moving path of the
film on a stretching device.
[0004] Once the drawing step(s) is/are completed, the drawn polymer film is "heat set" or
crystallized under tension and with a temperature gradient starting at elevated temperatures
and continuing to decreased temperatures. The heat setting step prevents the film
from shrinking back to its unstretched shape and locks the molecular orientation in
the polymer film plane. The orientation of the polymer molecule chains thus obtained
is responsible for the high strength and stiffness of the oriented film.
[0005] Finally, the polymer film stretched monoaxially or biaxially is guided to a take-up
roller to which the final polymer film is taken up for further processing or storage.
In the process of taking up the final polymer film by rotating said take-up roller,
the diameter of the roll (or bale on the roller) continuously increases. In order
to press the film coming out from the stretching plant to the take-up roller (or bale
of polymer film on the take-up roller) with the same predetermined pressure, a contact
roller is used. Said contact roller applies a steady pressure to the outermost polymer
film layer taken up to the take-up roller (or bale of polymer film already taken up
to the take-up roller).
[0006] When taking up the polymer film to the take-up roller at the end of the stretching
process, two problems already known from the prior art need to be dealt with:
- The diameter of the take-up roller holding the wound-up polymer film steadily increases,
which fact makes an adaptation of the contact roller's position, relative to the take-up
roller, necessary permanently.
- In the course of the step of winding, to the take-up roller, the polymer film running
towards the take-up roller with high speed, the bale consisting of continuous wound-up
layers of said polymer film becomes unround at least slightly. As a consequence, vibrations
of the contact roller/take-up roller unit may form, resulting into variations of the
contact pressure applied to the outer polymer film layer being wound to the take-up
roller (or bale of polymer film already taken up to the take-up roller). Such variations
of the pressure applied to the polymer film being wound are undesired due to their
apparent disadvantages for the polymer film wound-up.
[0007] In order to overcome such problems, the prior art proposed that a two-step pressure
adaptation be performed: A constant pressure of the pressure roller to the take-up
roller in the course of an increasing diameter of the bale of wound polymer material
at the take-up roller was maintained by means of a lever mechanism. In addition, the
variations of pressure resulting from vibrations and making necessary an adjustment
over distances in the order of few (up to 30) millimeters (mm) were damped by hydraulic
dampening cylinders. The roller itself was moved along one or several linear guidance(s).
Such an arrangement resulted into a reduction of the problems. However, it was considered
highly disadvantageous that the operation of the contact roller / take-up roller unit
in the overall plant needed a multipart arrangement at the articulation sites of the
rollers, at which, in the course of a long-time operation, a play at the articulation
sites increased, resulting in turn to an unsteady movement of the articulation parts.
Finally, the overall plant operation had to be stopped too often in order to allow
a replacement of used parts of the contact roller / take-up roller unit not working
properly.
[0008] The document
EP-B 1 423 318 proposed a countercontrol for a linear motor drive driving the contact roller with
the aim of maintaining an improved contact pressure during the entire process of taking
up the polymer film to the take-up roller. The contact pressure force, i. e. in general
the force produced by the linear motor, may change depending upon the vibration state
in order to ensure the application of a contact pressure in a way as uniform as possible.
The arrangement causes an increase or decrease of the force on the movable part of
the driving motor and, thus, on the line of contact between the contact roller and
the take-up roller, or the bale which is wounded onto the take-up roller, preferably
such that the relieve motion between the two rollers, compared to an uncorrected state,
is minimized or even becomes zero (or at least tends to become zero) so that unwanted
vibrations (relative vibrations or changes of the distance of the rollers) are prevented
thereby.
[0009] A major disadvantage of using the linear motor for preventing vibrations or relative
changes of the distance between the two rollers is that a linear motor (as used in
the prior art
EP-B 1 423 318), due to an arrangement of the stationary magnets along a linear (open loop) circuitry,
tends to suffer from considerable cogging due to the finite number of magnetic poles,
which cogging makes difficult, if not impossible, providing a continuous linear control
of the pressure exerted by the contact roller towards the take-up roller, on the one
hand, and effecting a damping effect in cases of vibrations and changes of the relative
distance between the take-up and contact rollers in the course of the process of taking
up the polymer film drawn, on the other hand.
[0010] It was now surprisingly found that the above disadvantages of the prior art can be
overcome by driving the movement of the contact roller as a whole, or even of each
journal thereof, towards, or away from, the take-up roller by a direct (gearless drive)
motor. Thereby, the above disadvantages can reliably be overcome, and a constant pressure
of the contact roller towards the take-up roller, as well as a damping of take-up
roller rotary movements by the maintenance of the contact roller pressure is achieved.
[0011] Hence, the invention relates to a device for operating at least one contact roller
in contact with a take-up roller or with a polymer film bale wound to the take-up
roller, preferably in a plant for stretching a polymer film which is, after the stretching
step, wound to said take-up roller rotatable around a rotational axis, said at least
one contact roller being rotatable around a rotational axis arranged parallel to the
take-up roller's rotational axis, being supported movably by variable distances perpendicular
relative to the take-up roller's rotational axis and providing for a permanent application
of a predetermined pressure to the polymer film during said winding to the take-up
roller or polymer film bale along a contact line being on the surface of the contact
roller and take-up roller or polymer film bale and parallel to the axes of the take-up
and contact rollers, said device comprising
- at least one direct gearless-drive motor means for exerting a rotational drive force
around a motor axis;
- said motor axis being substantially parallel to the axes of the contact and take-up
rollers and being capable of actuating force transmission means by its rotational
movement;
- said force transmission means being connected to and actuated by said motor means
and transforming the rotational drive force around the axis and exerted by the direct
gearless-drive motor means into a translational drive force substantially perpendicular
to the motor axis;
- said force transmission means being capable of transmitting said translational drive
force to the contact roller, thereby moving the contact roller towards, or away from,
the take-up roller.
[0012] Preferred embodiments of said device are claimed in dependent claims 2 to 5 and 9.
[0013] The invention also relates to a device for operating at least one contact roller
in contact with a take-up roller or with a polymer film bale wound to the take-up
roller, preferably in a plant for stretching a polymer film which is, after the stretching
step, wound to said take-up roller rotatable around a rotational axis, said at least
one contact roller being rotatable around a rotational axis arranged parallel to the
take-up roller's rotational axis, being supported movably by variable distances perpendicular
relative to the take-up roller's rotational axis and providing for a permanent application
of a predetermined pressure to the polymer film during said winding to the take-up
roller or polymer film bale along a contact line being on the surface of the contact
roller and take-up roller or polymer film bale and parallel to the axes of the take-up
and contact rollers, said device comprising
- at least one direct gearless-drive motor means for exerting a rotational drive force
around a motor axis;
- said motor axis being substantially parallel to the axes of the contact and take-up
rollers and being capable of actuating force transmission means by its rotational
movement;
- said direct gearless-drive motor means being arranged above or below said contact
roller;
- said force transmission means connected to and actuated by said direct gearless drive
motor means and transforming the rotational drive force exerted by the axis of the
direct gearless-drive motor means into a translational drive force in the direction
of a circular arc around the motor axis;
- said force transmission means being capable of transmitting said translational drive
force to the contact roller, thereby moving the contact roller towards, or away from,
the take-up roller.
[0014] Preferred embodiments of the latter device are claimed in dependent claims 7 to 9.
[0015] The invention further relates to a process for operating at least one contact roller
in contact with a take-up roller or with a polymer film bale wound to the take-up
roller, preferably in a plant for stretching a polymer film which is, after the stretching
step, wound to said take-up roller rotatable around a rotational axis, said at least
one contact roller being rotatable around a rotational axis arranged parallel to the
take-up roller's rotational axis and being supported movably by variable distances
perpendicular relative to the take-up roller's rotational axis, wherein a predetermined
pressure is applied permanently to the polymer film by said contact roller during
said winding to the take-up roller or polymer film bale along a contact line being
on the surface of the contact roller and take-up roller or polymer film bale and parallel
to the axes of the take-up and contact rollers, said process comprising
- providing at least one direct gearless-drive motor means for exerting a rotational
drive force around a motor axis;
- adjusting the direction of said motor axis to be substantially parallel to the axes
of the contact and take-up rollers and making the motor means capable of actuating
force transmission means by its rotational movement;
- providing a force transmission means connected to and actuated by said motor means,
said force transmission means transforming the rotational drive force exerted by the
axis of the direct gearless-drive motor means into a translational drive force substantially
perpendicular to the motor axis; and
- allowing said force transmission means to transmit said translational drive force
to the contact roller, thereby moving the contact roller towards, or away from, the
take-up roller.
[0016] Preferred embodiments of said process are claimed in dependent claims 11 to 14 and
18.
[0017] Finally, the invention also relates to a process for operating at least one contact
roller in contact with a take-up roller or with a polymer film bale wound to the take-up
roller, preferably in a plant for stretching a polymer film which is, after the stretching
step, wound to said take-up roller rotatable around a rotational axis, said at least
one contact roller being rotatable around a rotational axis arranged parallel to the
take-up roller's rotational axis and being supported movably by variable distances
perpendicular relative to the take-up roller's rotational axis, wherein a predetermined
pressure is applied permanently to the polymer film by said contact roller during
said winding to the take-up roller or polymer film bale along a contact line being
on the surface of the contact roller and take-up roller or polymer film bale and parallel
to the axes of the take-up and contact rollers, said process comprising
- providing at least one direct gearless-drive motor means for exerting a rotational
drive force around a motor axis;
- adjusting the direction of said motor axis to be substantially parallel to the axes
of the contact and take-up rollers and making the motor means capable of actuating
force transmission means by its rotational movement;
- providing said direct gearless-drive motor means to be arranged above or below said
contact roller;
- providing a force transmission means connected to and actuated by said motor means,
said force transmission means transforming the rotational drive force exerted by the
axis of the direct gearless-drive motor means into a translational drive force in
the direction of a circular arc around the motor axis; and
- allowing said force transmission means to transmit said translational drive force
to the contact roller, thereby moving the contact roller towards, or away from, the
take-up roller.
[0018] Preferred embodiments of the latter process are claimed in dependent claims 16 to
18.
[0019] In developing further the prior art (e. g. as disclosed in the document
EP-A 1 423 318), the device and process of the invention can provide the functions of
- applying a permanent uniform contact pressure of the contact roller to the polymer
film to be wound to the take-up roller or to the bale of polymer film material already
wound to the take-up roller, thereby ensuring an appropriate winding of the stretched
polymer film to the take-up roller;
- allowing the contact roller to be removed from, or moving the contact roller back
to, the take-up roller, thereby releasing contact pressure from, or again starting
application of, or increasing, contact pressure to, the polymer film wound to the
take-up roller or bale of polymer film material already wound to the take-up roller;
- applying, by means of the contact roller operated in accordance with the invention,
said contact roller to the empty take-up roller or bale of polymer film already wound
to the take-up roller with a predetermined mechanical pressure, said pressure being
applied along a line parallel to the axes of the rollers contacting;
- damping the forces transmitted by the take-up roller or bale of polymer film already
wound to the take-up roller, due to an out-of-round rotation thereof, to the contact
roller by means of a suitable control of the damping effect of the motor means to
the contact roller and its position relative to the take-up roller or bale of polymer
film wound to the take-up roller.
[0020] Hence, the at least one direct gearless-drive motor means is, in preferred embodiments
of the invention, used as contact pressure element providing for an optimum contact
pressure of the contact roller to the polymer film to be wound to the take-up roller
(or to the bale of polymer film material already wound to the contact roller), as
well as it is used as a damping means for the contact roller. In a surprisingly advantageous
manner, the direct gearless drive motor means employed in the present device, due
to an arrangement of the motor's stationary magnets along a closed loop circuitry
allows a substantial reduction, if not even a disappearance, of the cogging phenomenon.
As a consequence, a continuous linear control of the pressure exerted by the contact
roller towards the take-up roller can be ensured. In addition, in cases of vibrations
of the take-up roller following an out-of-round rotation thereof, and of resulting
changes of the relative distance between the take-up and contact rollers, a damping
effect and a minimization, if not even a disappearance, of losses of contact between
the take-up and contact rollers along their contact line can be achieved by the continuous
linear control of the pressure exerted by the contact roller towards the take-up roller
during the whole process of winding up the polymer drawn by the stretching device
to the take-up roller.
[0021] The term "comprise", "comprises" or "comprising" as used in the present specification
and claims, for example in claim 1 (device claim) or in the description of the device,
is defined to have the meaning that said device of the invention may comprise (or
include) (i) at least one component of the device following said term "comprise" or
"comprises" or "comprising" or may comprise (or include) (ii) two or more components
of the device following said term "comprise" or "comprises" or "comprising", or that
(iii) further components (more specifically defined below) may also be comprised by
the device of the invention. The same is applicable also to the method claims and
description of the method of the present invention,
mutatis mutandis.
[0022] The term "comprise" "comprises" or "comprising" as used in the present specification
and claims is, however, also defined for the present invention to optionally include
cases where the apparatus of the invention mainly (or even exclusively) consists of
(i) at least one component of the device following said term "comprise" or "comprises"
or "comprising" or mainly (or even exclusively) consists of (ii) two or more components
of the device following said term "comprise" or "comprises" or "comprising", optionally
together with any necessary component a skilled person may optionally additionally
include into such a device in order to achieve the object of the invention, or may
even include cases where the component of the device following said term "comprise"
or "comprises" or "comprising" exclusively consists of (i) at least one component
named or exclusively consists of (ii) two or more components named, optionally together
with any necessary component a skilled person may include into such a device in order
to achieve the object of the invention. The same is applicable also to the method
claims and description of the method of the present invention,
mutatis mutandis.
[0023] In other words: The term "comprise" or "comprises" or "comprising" may have, in the
present specification and claims, the meanings of describing, or claiming, an exhaustive
or, alternatively, a non-exhaustive enumeration of elements, without that, in the
former case, embodiments are excluded which, for example in sub-claims of the present
application and corresponding parts of the specification, claim (and describe) further
features, which are beneficial or advantageous but not essential for the present invention.
[0024] The invention is now further described in detail by referring to the attached Figures.
However, the subsequent description, and the Figures as well, are not intended to
restrict the invention to the preferred embodiments shown or explained in detail;
such description and Figures show, as examples only, preferred embodiments of the
invention serving a better understanding of the principles of the invention. In the
Figures,
- Figure 1 shows one embodiment of the device of the present invention, wherein at least
one linear guidance is used, on which the motor means moves the contact roller towards
(and away from) the take-up roller via a rocker arm as a force transmission means;
- Figure 2 shows another embodiment of the device of the present invention, wherein
at least one linear guidance is used, on which the motor means moves the contact roller
towards (and away from) the take-up roller via a cograil/cogwheel combination as a
force transmission means;
- Figure 3 shows another embodiment of the device of the present invention, wherein
the contact roller is pending below the motor means, and the motor means is transmitting
the translational force via a pendulum-like transmission means or pendulum arm to
the contact roller; and
- Figure 4 shows another embodiment of the device of the present invention wherein at
least one linear guidance is used, on which motor means move the contact roller towards
(and away from) the take-up roller via a cograil/cogwheel combination as a force transmission
means.
[0025] Preferred, but exemplary (and non-restricting) embodiments of the present invention,
i. e. of the device and of the process of the present invention, are now explained
in detail by referring to the Figures.
[0026] Figure 1 shows one embodiment of the device of the present invention, wherein at
least one linear guidance 30 is used, on which the motor means 10, via the intermediate
force transmission means 20, moves the contact roller 1 towards (or away from) the
take-up roller 0, wherein a rocker arm 21 is used as a force transmission means 20.
For the further description, reference is made to Figure 1.
[0027] A polymer film 2, arriving from previous, i. e. process-upstream, steps of treatment
of the film, preferably arriving from the previous, i. e. process-upstream, steps
of stretching, monoaxially or biaxially, on a usual stretching plant, is wound continuously
to a take-up roller 0, or to a bale 0' of polymer film material already wound to said
take-up roller 0. In order to appropriately allow the polymer film 2 to be wound,
or taken up, to the take-up roller 0, the take-up roller 0 is driven, by suitable
separate motor means (not shown here), at a variable predetermined velocity.
[0028] The axis of the take-up roller 0 is usually supported to be stationary, e. g. is
supported on a suitable stationary stand which may form part of the stretching device.
[0029] In contact with the take-up roller 0, or with the polymer material wound to said
take-up roller 0, is at least one contact roller 1. There may be one contact roller,
or there may be more than one (e. g. two or even three) contact roller(s) 1. In preferred
embodiments of the invention, there is exactly one contact roller 1 in contact with
the take-up roller 0 or with a bale 0' of polymer film material already wound to said
take-up roller 0.
[0030] The contact roller 1 (or in cases where more than one contact roller 1 is used: the
contact rollers 1, 1) may be mounted on a stand or base or frame or to a suspension
in such a manner that the rotational axes of the take-up roller 0 and of the (preferably
one and optionally more than one) contact roller 1 are substantially parallel to each
other, and that the surface of the contact roller(s) 1 is in rotational contact to
the surface of the (empty) take-up roller 0 or is in contact to the outermost polymer
film layer already wound to the take-up roller 0 (if polymer film is already wound
to the take-up roller 0). If so, the contact roller surface contacts the take-up roller
surface (or the surface of the bale of polymer material already wound to the take-up
roller 0) along a contact line which is also parallel to the rotational axes of the
take-up and contact rollers 0, 1.
[0031] In the present invention (as also in the prior art, e. g. as described in the document
EP-A 1 423 318) the contact roller 1 (e. g. mounted on a stand or base or frame or to a suspension)
is movable, relative to the take-up roller 0, and variable distances of the contact
roller 1, relative to the rotational axis of the take-up roller 0, may be adjusted
including a distance between the contact roller 1 and the take-up roller 0 where the
surfaces of the contact and take-up rollers 1, 0 (or the surface of the contact roller
1 and the surface of the outermost polymer film layer wound to the take-up roller
0) are in contact along a contact line parallel to the rotational axes of the contact
and take-up rollers 1, 0.
[0032] At the beginning of the take-up process, the take-up roller 0 is empty, and the surfaces
of the take-up roller 0 and of the contact roller 1 are in direct contact. With a
continuing take-up process, the diameter of the bale 0' of polymer film material already
wound to the take-up roller 0 increases. In order to support the aim of effecting
a smooth, flat and substantially waveless winding of the polymer film 2 to the take-up
roller 0, the arriving polymer film 2 is pressed to the surface of the empty take-up
roller 0 (or, if already some polymer film 2 was wound to the take-up roller 0, to
the surface of the polymer film bale 0' already wound to the take-up roller 0) by
means of the contact roller 1 at a predetermined pressure.
[0033] In accordance with the present invention, the axis of the contact roller 1 is adjustable
to match to the take-up roller diameter increasing in the course of the take-up (or
winding) process. For such a purpose, the contact roller 1 (or in case that more than
one contact roller is employed: the contact rollers 1) is/are supported movably by
variable distances relative to the take-up roller's rotational axis. A skilled person
knows possibilities of arranging a contact roller movably relative to a take-up roller
0, and all such possibilities may be employed in the present invention in accordance
with the requirements. Preferred examples of movable arrangements are guidances, e.
g. rails or rolls, allowing a movement of the contact roller 1 towards, or away from,
a take-up roller 0, controlled and/or actuated by suitable means also known to a skilled
person. Similarly, movably pending or movably upstanding arrangements of the contact
roller 1 are conceivable. In one preferred embodiment (described below in more detail),
the contact roller 1 is mounted to at least one linear guidance (e. g. the at least
one linear guidance found in Figures 1 and 2 at "30"). In another preferred embodiment
described below in detail with reference to Figure 3, the contact roller 1 is mounted
to a suspension in a pending arrangement, relative to the take-up roller 0.
[0034] In cases where the contact roller 1 is mounted to at least one linear guidance 30,
there may be used one linear guidance, or there may be used more than one (e. g. two,
three or even four) linear guidance(s). The use of one linear guidance or of an even
number of linear guidances, e. g. two linear guidances, is preferred in the present
invention. As will be appreciated by a skilled person, the linear guidance(s) has/have
to receive the bearings for the rollers, in this case: for the at least one contact
roller(s) 1, and serve the contact rollers' movement when actuated in accordance with
the present invention. The linear guidance(s) also transmit all forces resulting from
the roller rotation (including the rotation of the contact roller 1 in response to
its contact to the take-up roller 0) into the mounting frame of the overall plant.
Such forces may have high values, for example in cases where the take-up roller 0
effects "unround" rotations due to waves in the polymer wound to the take-up roller
0. Hence, a proper and stable support by the at least one linear guidance (30) is
required essentially.
[0035] In a usual process of winding a polymer film 2 to a take-up roller 0, the contact
roller 1 provides for a permanent application of a predetermined pressure to the polymer
film 2 at the contact point or - better - along the contact line. The term "predetermined
pressure", as used in the present specification and claims, is defined to mean a pressure
of the outer surface of the contact roller 1 applied to the outer surface of the take-up
roller 0 (or, if already some polymer film 2 was wound to the take-up roller 0, to
the surface of the polymer film bale 0' already wound to the take-up roller 0) which
is just sufficient to effect a smooth and waveless winding of the polymer film, in
large numbers of layers wound, to the take-up roller 0. This is effected technically
in a manner known per se to a skilled person, preferably - in accordance with the
invention - by applying a suitable (ideally: constant) momentum to the direct gearless
drive motor means 10, e. g. by applying a suitable (ideally constant) current. In
exemplary embodiments of the invention, the pressure applied by the contact roller
1 to the take-up roller 0 (or to the outermost polymer film layer wound to the take-up
roller 0) is in a range of from 100 N to 5,000 N (without restricting the invention
to this range).
[0036] The axis of the contact roller 1 is preferably supported on bearings allowing a smooth
movement or rotation of the contact roller 1.
[0037] In accordance with the present invention, the device comprises at least one direct
gearless-drive motor means 10, preferably one direct gearless-drive motor means 10
or two direct gearless-drive motor means 10, 10, more preferably one direct gearless-drive
motor means 10, for exerting a rotational drive force around a motor axis 11. Said
direct gearless-drive motor means 10 is/are used for the purpose of keeping the outer
surface the contact roller 1 in a permanent and uniform contact with the outer surface
of the take-up roller 0 (if the latter is empty and has not yet wound to it any polymer
film material 2) or with the outer surface of the bale 0' of polymer material already
wound to the take-up roller 0, while applying a predetermined pressure to the polymer
film wound to the take-up roller 0. The at least one direct gearless-drive motor means
10 is capable of exerting a rotational drive force around a motor axis 11. This is
shown in the Figures by the double arrow 40: The force exerted may be directed into
both rotational directions.
[0038] In accordance with the present invention, the axis 11 of the at least one direct
gearless-drive motor means 10 is substantially parallel to the axes of the contact
roller 1 and of the take-up roller 0.
[0039] The advantage of using at least one direct gearless-drive motor means 10 in the device
of the present invention is as follows: Due to the arrangement of the motor's stationary
magnets along a closed loop circuitry, a substantial reduction, if not even a disappearance,
of the cogging phenomenon can be effected. As a consequence, a cogging-free actuation
of the direct gearless drive motor's action may occur, into both directions indicated
in Figure 1 by the directional arrow 40. This cogging-free actuation may lead to a
continuous linear movement of a force transmission means 20 connected to the motor
means 10 and, in turn, may result into a continuous linear control of the pressure
exerted by the contact roller 1 towards the take-up roller 0 at any distance between
the contact roller outer surface from the take-up roller rotational axis. In addition,
in cases of vibrations of the take-up roller 0 following an out-of-round rotation
thereof, and of resulting changes of the relative distance between the take-up and
contact rollers 0, 1, a damping effect and a minimization, if not even a disappearance,
of losses of contact between the take-up and contact rollers 0, 1 along their contact
line can be achieved by the continuous linear control of the pressure exerted by the
contact roller 1 towards the take-up roller 0 during the whole process of winding
up the polymer drawn by the stretching device to the take-up roller 0.
[0040] Due to the fact that, in view of the stationary position of the take-up roller axis,
the outer surface of the bale of polymer film material is changing its position permanently,
relative to the take-up roller axis, for example due to an increase of the bale diameter
with continuing winding of the polymer film to the take-up roller 0 or due to an out-of-round
rotation of the take-up roller 0 resulting from the polymer film 2 wound thereto,
the contact roller 1 must be variable in its position, relative to the take-up roller
axis. Simultaneously, a permanent application of a steady pressure to the polymer
film 2 by the contact roller 1 is desired. This is achieved, in accordance with the
present invention, by that the at least one direct gearless-drive motor means 10 is
capable of actuating a force transmission means 20 by its rotational movement around
the motor axis 11.
[0041] In a preferred embodiment of the device of the present invention for operating at
least one contact roller 1, the at least one direct gearless-drive motor means 10,
preferably one direct gearless-drive motor means 10, is mounted to a separate stand
31 in operational distance to the contact roller (1).
[0042] The term "in operational distance" as used in the present specification and claims
is understood to mean that the at least one direct gearless-drive motor means 10,
preferably one direct gearless-drive motor means 10, is mounted at a distance from
the contact roller 1 which can ensure that the motor means 10 may not only actuate
a force transmission means 20 by its rotational movement around the motor axis 10,
but also the force exerted onto the force transmission means 20 is transferred to
the contact roller 1 for its movement towards, and away from, the take-up roller.
In this embodiment of the invention, the at least one motor means has/have a fixed
position, while the contact roller 1 moves, relative to the motor means 10, with the
action of the force transmission means 20.
[0043] In another, alternative, albeit preferred, embodiment of the invention, the at least
one direct gearless-drive motor means 10, preferably two direct gearless-drive motor
means 10, is/are mounted to one journal or to both journals of the contact roller
1 in operational distance to a separate stand 31. In this embodiment, at least one
motor means 10 is, preferably two motor means 10, 10 are moving together with the
contact roller 10, relative to the fixed stand 31, with the action of the force transmission
means 20, one end of which is fixed to the fixed stand 31.
[0044] In accordance with the present invention, the device for operating a contact roller
1 comprises a force transmission means 20 connected to and actuated by said at least
one direct gearless-drive motor means 10. Said force transmission means 20 is capable
of transforming, and in operation actually transforms, the rotational drive force
around the axis 11 and exerted by the direct gearless-drive motor means 10 into a
translational drive force substantially perpendicular to the motor axis 11. In accordance
with the invention, said force transmission means 20 is capable of transmitting, and
in operation actually transmits, said translational drive force to the contact roller
1, thereby moving the contact roller 1 towards, or away from, the take-up roller 0.
The directions of movement are shown in Figure 1 by the double-arrow 41 and are perpendicular
to the rotational axes of the take-up and contact rollers 0, 1.
[0045] In a preferred embodiment of the invention, the device for operating a contact roller
1 comprises at least one linear guidance 30, preferably exactly one linear guidance
30 or an even number of linear guidances 30, e. g. two linear guidances 30, 30, on
which the contact roller 1 or the bearing and support on which the contact roller
1 is supported may be moved in linear directions towards, or away from, the take-up
roller 0. Figures 1 and 2 show one linear guidance 30 exemplarily, but without restricting
the invention to such an embodiment. The movement is effected in accordance with the
invention by the translational drive force effected by said force transmission means
20 upon actuation by the force transmission means 20 which, in turn, is actuated by
the direct gearless-drive motor means 10 rotating around the motor axis 11. By using
a linear guidance 30, the translational drive force can be applied to the contact
roller in a smooth and reliable manner allowing the application of the desired pressure
to the polymer film 2 to be wound to the take-up roller 0.
[0046] In another preferred, and particularly advantageous, embodiment of the invention
shown in Figure 1, the device for operating a contact roller 1 comprises a rocker
arm 21 as the force transmission means 20.
[0047] In the case where the direct gearless drive motor means 10 is mounted to a separate
stand 31, said rocker arm 21 is pivotably connecting a disk 22 to the bearing of the
contact roller axis, said disk 22 being driven by the motor 10 rotationally around
the motor axis 11. By this preferred embodiment, the contact roller 1 is moved towards,
and away from, the take-up roller 0 or the bale 0' wound thereto so as to apply a
predetermined pressure to the polymer film 2 wound to the take-up roller 0. This embodiment
is shown in Figure 1
[0048] In the case where the direct gearless drive motor means 10 is mounted to the journal
of the contact roller, or where two direct gearless drive motor means 10, 10 are mounted
to the journals of the contact roller 1, one rocker arm 21 is pivotably connecting
one disk 22 driven by the motor means 10 rotationally around the motor axis 11, and
at least one fixation point at the separate stand 31, or two rocker arms 21, 21 are
pivotably connecting two disks 22, 22 driven by two motor means 10, 10 rotationally
around the respective motor axes 11, 11, and at least one fixation point at the separate
stand 31. By this preferred embodiment, the contact roller 1 is moved towards, and
away from, the take-up roller 0 or the bale 0' wound thereto so as to apply a predetermined
pressure to the polymer film 2 wound to the take-up roller 0.
[0049] In other words, in accordance with these embodiments, the rotational movement driving
force exerted by the motor 10 rotationally around the motor axis 11 is transformed
into a linear or translational movement driving force by means of a mechanical transformation
element, which is the rocker arm 21 proposed as the force transmission means 20. The
translational movement of the contact roller 1 initiated by the rocker arm 21 occurs
on the linear guidance 30 also shown in Figure 1. The directions of movement are shown
in Figure 1 by the double-arrow 41.
[0050] In an even more preferred embodiment, the transformation of the rotational movement
driving force of the direct gearless-drive motor 10 into the linear or translational
movement driving force is effected around the top and bottom dead center positions
of the motor axis 11 towards the contact roller centre. The latter embodiment is particularly
advantageous, since a relatively small rotational movement of the motor axis 11 transmits
into a relatively small translational movement of the force transmission means 20,
especially of the rocker arm 21, as shown in Figure 1. Thus, a sensitive movement
of the contact roller 1 towards, or away from, the take-up roller 0 may be achieved,
resulting into a similarly sensitive pressure application onto the take-up roller
0 or the polymer film 2 wound to the take-up roller 0.
[0051] In addition, a substantial reduction, if not even a disappearance, of the cogging
phenomenon can be effected by using the direct gearless drive motor means 10. As a
consequence, a cogging-free actuation of the direct gearless drive motor's action
may be initiated into both directions indicated in Figure 1 by the directional arrow
40. Such a cogging-free actuation may lead to a continuous linear movement of the
rocker arm 21 used as the force transmission means 20 connected to the motor means
10 and, in turn, may result into a continuous linear control of the pressure exerted
by the contact roller 1 towards the take-up roller 0 at any distance between the contact
roller outer surface from the take-up roller rotational axis. In addition, in cases
of vibrations of the take-up roller 0 following an out-of-round rotation thereof,
and of resulting changes of the relative distance between the take-up and contact
rollers 0, 1, a damping effect and a minimization, if not even a disappearance, of
losses of contact between the take-up and contact rollers 0, 1 along their contact
line can be achieved by the continuous linear control of the pressure exerted by the
contact roller 1 towards the take-up roller 0 during the whole process of winding
up the polymer drawn by the stretching device to the take-up roller 0.
[0052] In an alternative and similarly preferred embodiment of the invention shown in Figure
2, the device for operating a contact roller 1 comprises a cograil 25 as the force
transmission means 20.
[0053] In the case where the direct gearless drive motor means 10 is mounted to a separate
stand 31, said cograil 25 is pivotably connecting a cogwheel 26 driven by the motor
axis 11 rotationally to the bearing of the contact roller axis. By this preferred
embodiment, the contact roller 1 is moved towards, and away from, the take-up roller
0 or the bale 0' wound thereto so as to apply a predetermined pressure to the take-up
roller or the polymer film 2 wound to the take-up roller 0. The directions of movement
are shown in Figure 2 by the double-arrow 41.
[0054] In the case where the direct gearless drive motor means 10 is mounted to the journal
of the contact roller 1, or where two direct gearless drive motor means 10, 10 are
mounted to the journals of the contact roller 1, one cograil 25 is pivotably connecting
one cogwheel 26 driven by the motor means 10 rotationally around the motor axis 11,
and at least one fixation point at the separate stand 31, or two cograils 25, 25 are
pivotably connecting two cogwheels 26, 26 driven by two motor means 10, 10 rotationally
around the respective motor axes 11, 11, and at least one fixation point at the separate
stand 31. By this preferred embodiment, the contact roller 1 is moved towards, and
away from, the take-up roller 0 or the bale 0' wound thereto so as to apply a predetermined
pressure to the polymer film 2 wound to the take-up roller 0. The latter embodiment
is shown in Figure 4, where only one motor means 10, one cogwheel 26 and one cograil
25 fixed to one fixation point at a fixed stand 31 are shown for reasons of simplicity.
[0055] In other words: In accordance with this embodiment, the rotational movement driving
force of the motor 10 around the motor axis 11 is transformed into a linear or translational
movement driving force by means of a mechanical transformation element which is the
cograil 25 proposed as the force transmission means 20. The translational movement
of the contact roller 1 transmitted by the cograil 25 and initiated by the cogwheel
26 driven by the direct gearless-drive motor means 10 occurs on the linear guidance
30 also shown in Figures 2 and 4.
[0056] In an even more preferred embodiment, the transformation of the rotational movement
driving force of the direct gearless-drive motor 10 into the linear or translational
movement driving force is effected around the top and bottom dead center positions
of the motor axis 11 towards the contact roller centre. The latter embodiment is particularly
advantageous, since a relatively small rotational movement of the motor axis 11 transmits
into a relatively small translational movement of the force transmission means 20,
especially of the cograil 25 as transmitted by the cogwheel 26, as shown in Figures
2 and 4. Thus, a sensitive movement of the contact roller 1 towards, or away from,
the take-up roller 0 may be achieved, resulting into a similarly sensitive pressure
application onto the take-up roller 0 or the polymer film 2 wound to the take-up roller
0. The directions of movement are shown in Figures 2 and 4 by the double-arrow 41.
[0057] The effect of using the direct gearless drive motor means 10 in combination with
the cograil/cogwheel force transmission means combination of this embodiment is particularly
advantageous: A substantial reduction, if not even a disappearance, of the cogging
phenomenon can be achieved. As a consequence, a cogging-free actuation of the direct
gearless drive motor's action may occur, into both directions indicated in Figures
2 and 4 by the directional arrow 40. This cogging-free actuation may lead to a continuous
linear movement of the cograil 25 used as the force transmission means 20 connected
to the motor means 10 via the cogwheel 26 and, in turn, may result into a continuous
linear control of the pressure exerted by the contact roller 1 towards the take-up
roller 0 at any distance between the contact roller outer surface from the take-up
roller rotational axis. In addition, in cases of vibrations of the take-up roller
0 following an out-of-round rotation thereof, and of resulting changes of the relative
distance between the take-up and contact rollers 0, 1, a damping effect and a minimization,
if not even a disappearance, of losses of contact between the take-up and contact
rollers 0, 1 along their contact line can be achieved by the continuous linear control
of the pressure exerted by the contact roller 1 towards the take-up roller 0 during
the whole process of winding up the polymer drawn by the stretching device to the
take-up roller 0.
[0058] In accordance with an alternative of the present invention, the contact roller 1
may be in a pendulum-like arrangement with respect to the direct gearless-drive motor
means 10 of the present invention. This embodiment is exemplarily described while
referring to Figure 3 attached hereto. The invention comprises cases, where the direct
gearless drive motor means 10 is arranged above said contact roller 1 (as shown in
Figure 3 exemplarily, but without restriction) or where the direct gearless drive
motor means is arranged below said contact roller 1 (not shown in a Figure).
[0059] In accordance with the latter embodiment of the present invention, the direct gearless-drive
motor means 10 is used for the purpose of keeping the outer surface the contact roller
1 in a permanent and uniform contact with the outer surface of the take-up roller
0 (if the latter is empty and has not yet wound to it any polymer film material 2)
or with the outer surface of the bale 0' of polymer material already wound to the
take-up roller 0, while applying a predetermined pressure to the take-up roller outer
surface or the polymer film wound to the take-up roller 0. The direct gearless drive
motor means 10 is capable of exerting a rotational drive force around a motor axis
11. This is shown in the Figures by the double arrow 40: The force exerted may be
directed into both rotational directions.
[0060] In accordance with the present invention, the axis 11 of the direct gearless-drive
motor means 10 is substantially parallel to the axes of the contact roller 1 and of
the take-up roller 0.
[0061] Due to the fact that, in view of the stationary position of the take-up roller axis,
the outer surface of the bale 0' of polymer film material is changing its position
permanently, relative to the take-up roller axis, for example due to an increase of
the bale diameter with continuing winding of the polymer film to the take-up roller
0 or due to an out-of-round rotation of the take-up roller 0 resulting from the polymer
film 2 wound thereto, the contact roller 1 must be variable in its position relative
to the take-up roller axis. Simultaneously, a permanent application of a steady pressure
to the polymer film 2 by the contact roller 1 is desired. This is achieved, in accordance
with the present invention, by that the direct gearless-drive motor means 10 is capable
of actuating the pendulum-like force transmission means by its rotational movement
around its rotational axis 11.
[0062] In this embodiment of the invention, said direct gearless-drive motor means 10 is
arranged above the contact roller 1. By such an arrangement, a smooth actuation of
a force transmission means 20 by said direct gearless motor means 10 may be achieved,
resulting into transformation of the rotational drive force exerted by the motor means
10 around the motor axis 11 into a translational drive force to the contact roller
1. Thereby a smooth and continuous movement of the contact roller 1 towards, or away
from, the take-up roller 0 is achieved.
[0063] In accordance with the present invention, the device for operating a contact roller
1 comprises a force transmission means 20 connected to and actuated by said direct
gearless drive motor means 10. Said force transmission means 20 is capable of transforming,
and in operation actually transforms, the rotational drive force exerted by the axis
11 of the direct gearless-drive motor means 10 into a translational drive force substantially
perpendicular to the motor axis 11. In accordance with the invention, said force transmission
means 20 is capable of transmitting, and in operation actually transmits, said translational
drive force to the contact roller 1, thereby moving the contact roller 1 towards,
or away from, the take-up roller 0.
[0064] In another preferred embodiment of the invention not shown in the Figures, the device
for operating a contact roller 1 comprises a rocker arm 21 as the force transmission
means 20. Said rocker arm 21 is pivotably connecting a disk 22 driven by the motor
axis 11 rotationally above the contact roller 1 to the bearing of the contact roller
axis. By this preferred embodiment, the contact roller 1 is moved towards, and away
from, the take-up roller 0 or the bale 0' wound thereto so as to apply a predetermined
pressure to the polymer film 2 wound to the take-up roller 0.
[0065] In other words, in accordance with this embodiment, the rotational movement driving
force of the motor axis 11 is transformed into a linear or translational movement
driving force by means of a mechanical transformation element which is the rocker
arm 21 positioned above the contact roller 1. The translational movement of the contact
roller 1 initiated by the rocker arm 21 may occurs on the linear guidance 30. The
directions of movement are similar to those shown in Figure 1 by the double-arrow
41.
[0066] In a further preferred embodiment of the invention which is shown in Figure 3 exemplarily,
the device for operating a contact roller 1 comprises a pendulum arm 23 as the force
transmission means 20. The pendulum arm 23 is capable of pivotably connecting, and
in operation actually connects, the direct gearless drive motor means 10 and its rotating
motor axis 11 fixed at one end of the pendulum arm 23 to the bearing of the contact
roller axis pending at the other end of the pendulum arm 23. When actuating the direct
gearless drive motor means 10 and thereby rotating the pendulum arm 23 around the
motor axis 11, a movement of the contact roller 1 towards, and away from, the take-up
roller 0 or the bale 0' wound thereto in the direction of a circular arc around the
motor axis 11 is effected, as shown by the arrow 42 in Figure 3. As a result, a predetermined
pressure is applied, by the contact roller 1 swinging like a pendulum around the direct
gearless-drive motor means axis 11 in the shape of a circular arc, to the take-up
roller 0 or to the polymer film 2 wound to the take-up roller 0.
[0067] As mentioned above already, in a preferred embodiment of the invention, the direct
gearless drive motor means 10 may be arranged above said contact roller 1 (as shown
in Figure 3 exemplarily, but without restriction). In alternative, albeit still preferred
embodiments of the invention, the direct gearless drive motor means may be arranged
below said contact roller 1. In all cases, the force transmission means 20 is not
restricted to the pendulum arm embodiment (shown in Figure 3 exemplarily), but may
also be embodied by a different translational force transmission means as, for example,
a rocker arm 21.
[0068] In a further preferred embodiment of the invention, the device for operating a contact
roller 1 according to the invention, as described above in all details, comprises
a force transmission means 20, 21, 23, 25 which connects to each of the journals of
the axis of the contact roller 1. Such a preferable arrangement allows a uniform application
of the translational force to the contact roller 1 and, thereby, an application of
a constant pressure of the contact roller 1 to the contact line between the contact
roller 1 and the take-up roller 0 or the bale of polymer film wound to the take-up
roller 0.
[0069] In accordance with the latter embodiment, an advantageous operation of the take-up
roller 0 in winding the polymer film drawn can be achieved: The use of the direct
gearless drive motor means 10 in the device of the invention achieves a substantial
reduction, if not even a disappearance, of the cogging phenomenon. As a consequence,
a cogging-free actuation of the direct gearless drive motor's action may occur, into
both directions indicated in Figure 3 by the directional arrow 40. This cogging-free
actuation may lead to a continuous movement of the pendulum 23 used as the force transmission
means 20 connected to the motor means 10 in the form of a circular arc around the
direct gearless drive motor axis 11 and, in turn, may result into a continuous linear
control of the pressure exerted by the contact roller 1 towards the take-up roller
0 at any distance between the contact roller outer surface from the take-up roller
rotational axis. In addition, in cases of vibrations of the take-up roller 0 following
an out-of-round rotation thereof, and of resulting changes of the relative distance
between the take-up and contact rollers 0, 1, a damping effect and a minimization,
if not even a disappearance, of losses of contact between the take-up and contact
rollers 0, 1 along their contact line can be achieved by the continuous linear control
of the pressure exerted by the contact roller 1 towards the take-up roller 0 during
the whole process of winding up the polymer drawn by the stretching device to the
take-up roller 0.
[0070] The invention further relates to processes for operating a contact roller 1 in contact
with a take-up roller 0 or with the bale 0' of a polymer film 2 to be wound to the
take-up roller 0. Such processes of the invention may be applicable for operating
plants from which polymer films 2 are obtained which have to be wound to a take-up
roller 0. Preferably, such processes are applicable for operating plants wherein polymer
films are stretched, either monoaxially or biaxially, so as to improve specific properties
of such polymer films, and the resulting films 2 have to be wound to a take-up roller
0 for storage of for further processing. All the steps of the process of operating
a contact roller 1 in accordance with the present invention are now described in detail
by referring to the above-described device for operating the contact roller 1. All
embodiments of the device of the present invention and already explained above in
detail are also applicable to the process of the invention described below in detail.
[0071] When storing a polymer film 2, arriving from previous steps of treatment of the film,
preferably arriving from the previous steps of stretching, monoaxially or biaxially,
on a usual stretching plant, such a film released by the treatment plant, preferably
by the stretching plant, is wound continuously to a take-up roller 0, or to a bale
0' of polymer film material already wound to said take-up roller 0. In order to appropriately
allow the polymer film 2 to be wound or taken up to the take-up roller 0, the take-up
roller 0 is driven, by suitable separate motor means (not shown here), at a variable
predetermined speed. At the beginning of the take-up process, the take-up roller 0
is empty, and the surfaces of the take-up roller 0 and of the contact roller 1 are
in direct contact. With a continuing take-up process, the diameter of the bale 0'
of polymer film material already wound to the take-up roller 0 increases. In order
to support the aim of effecting a smooth, flat and substantially waveless winding
of the polymer film 2 to the take-up roller 0, the arriving polymer film 2 is pressed
to the surface of the empty take-up roller 0 (or, if already some polymer film 2 was
wound to the take-up roller 0, to the surface of the polymer film bale 0' already
wound to the take-up roller 0) by means of the contact roller 1. For achieving said
aim, the axis of the take-up roller 0 and the axis of the contact roller 1 are arranged
to be substantially parallel to each other. If so, the contact roller surface contacts
the take-up roller surface (or the surface of the bale of polymer material already
wound to the take-up roller) along a certain line which is also parallel to the axes
of both rollers 0, 1. In addition, the axis of the take-up roller 0 is usually supported
to be stationary; the axis of the contact roller 1 must be adjustable to match to
the take-up roller diameter increasing in the course of the take-up (or winding) process.
[0072] In a usual process of winding such a polymer film 2 to a take-up roller 0, the contact
roller 1 provides for a permanent application of a predetermined pressure to the polymer
film 2 at the contact point or - better - contact line between the take-up roller
0 (or the polymer film bale 0' already wound to the take-up roller 0) and the contact
roller 1.
[0073] The axis of the contact roller 1 is usually supported on bearings allowing a smooth
movement or rotation of the contact roller. The contact roller 1, as described in
detail above in connection with the description of the device of the present invention,
is mounted on a stand or base or frame or is mounted to a suspension and, as mounted
to such a stand, base, frame or suspension, is movable, relative to the take-up roller
0. Thereby, variable distances of the contact roller 1, relative to the rotational
axis of the take-up roller 0, may be adjusted. Such distances include a distance between
the contact roller 1 and the take-up roller 0 where the surfaces of the contact and
take-up rollers 1, 0 (or the surface of the contact roller 1 and the surface of the
outermost polymer film layer wound to the take-up roller 0) are in contact along a
contact line parallel to the rotational axes of the contact and take-up rollers 1,
0.
[0074] In accordance with the process of the present invention, at least one direct gearless-drive
motor means 10, preferably one direct gearless-drive motor means 10 or two direct
gearless-drive motor means 10, 10, more preferably one direct gearless-drive motor
means 10, is/are provided for the purpose of keeping the outer surface the contact
roller 1 in a permanent and uniform contact with the outer surface of the take-up
roller 0 (if the latter is empty and has not yet wound to it any polymer film material
2) or with the outer surface of the bale 0' of polymer material already wound to the
take-up roller 0. Simultaneously and continuously during the winding process, a predetermined
pressure to the polymer film wound to the take-up roller 0 is adjusted by means of
the contact roller 1.
[0075] The at least one direct gearless drive motor means 10 is arranged for exerting a
rotational drive force by the motor 10 around the motor axis 11. This is shown in
the Figures by the double arrow 40. The force exerted may be directed into both rotational
directions.
[0076] In accordance with the present invention, the axis 11 of the at least one direct
gearless-drive motor means 10 is adjusted to be substantially parallel to the axes
of the contact roller 1 and of the take-up roller 0.
[0077] Due to the fact that, in view of the stationary position of the take-up roller axis,
the outer surface of the bale of polymer film material is changing its position permanently,
relative to the take-up roller axis, for example due to an increase of the bale diameter
with continuing winding of the polymer film to the take-up roller 0 or due to an out-of-round
rotation of the take-up roller 0 resulting from the polymer film 2 wound thereto,
the contact roller 1 must be made variable in its position relative to the take-up
roller axis. Simultaneously, a permanent application of a steady pressure to the polymer
film 2 by the contact roller is desired.
[0078] This is achieved, in accordance with the present invention, by making the at least
one direct gearless-drive motor means 10 actuating a force transmission means 20 by
its rotational movement.
[0079] In a preferred embodiment of the process of the present invention for operating at
least one contact roller 1, the at least one direct gearless-drive motor means 10,
preferably one direct gearless-drive motor means 10, is mounted to a separate stand
31 in operational distance to the contact roller (1).
[0080] As mentioned above, the term "in operational distance" is understood to mean that
the at least one direct gearless-drive motor means 10, preferably one direct gearless-drive
motor means 10, is mounted at a distance from the contact roller 1 which can ensure
that the motor means 10 may not only actuate a force transmission means 20 by its
rotational movement around the motor axis 10, but also the force exerted onto the
force transmission means 20 is transferred to the contact roller 1 for its movement
towards, and away from, the take-up roller 0. In this embodiment of the invention,
the at least one direct gearless drive motor means 10 has a fixed position, while
the contact roller 1 moves, relative to the motor means 10, with the action of the
force transmission means 20.
[0081] In another, alternative, albeit preferred, embodiment of the invention, the at least
one direct gearless-drive motor means 10, preferably two direct gearless-drive motor
means 10, is/are mounted to one journal or to both journals of the contact roller
1 in operational distance to a separate stand 31. In this embodiment, at least one
motor means 10 is, preferably two motor means 10, 10 are, moving together with the
contact roller 10, relative to the fixed stand 31, with the action of the force transmission
means 20, one end of which is fixed to the fixed stand 31.
[0082] In accordance with the present invention, the process for operating a contact roller
1 according to the invention comprises providing a force transmission means 20 connected
to, and actuated by, said at least one direct gearless drive motor means 10. Said
force transmission means 20 is made transforming, and in operation actually transforms,
the rotational drive force exerted by the direct gearless drive motor means 10 around
the axis 11 of the direct gearless-drive motor means 10 into a translational drive
force substantially perpendicular to the motor axis 11. In accordance with the invention,
said force transmission means 20 is made transmitting, and in operation actually transmits,
said translational drive force to the contact roller 1, thereby moving the contact
roller 1 towards, or away from, the take-up roller 0. The directions of movement are
shown in Figure 1 by the double-arrow 41. The force exerted may be directed into both
rotational directions.
[0083] In a preferred embodiment of the invention, the process for operating a contact roller
1 comprises providing a linear guidance 30 on which the contact roller 1 or the bearing
and support on which the contact roller 1 is supported may be moved in linear directions
towards, or away from, the take-up roller 0. The movement is effected in accordance
with the invention by the translational drive force effected by said transmission
means 20 upon actuation by the force transmission means 20 which, in turn, is actuated
by the direct gearless-drive motor means 10. By providing a linear guidance 30, the
translational drive force can be applied to the contact roller in a smooth and reliable
manner allowing the application of the desired pressure to the polymer film 2 to be
wound to the take-up roller 0.
[0084] The effect of the present process, by using the direct gearless drive motor means
10 in combination with the force transmission means 20, is particularly advantageous:
A substantial reduction, if not even a disappearance, of the cogging phenomenon can
be achieved. As a consequence, a cogging-free actuation of the direct gearless drive
motor's action may occur, into both directions indicated in the Figures by the directional
arrow 40. This cogging-free actuation leads to a continuous linear movement of the
force transmission means 20 connected to the direct gearless drive motor means 10
and, in turn, may result into a continuous linear control of the pressure exerted
by the contact roller 1 towards the take-up roller 0 at any distance between the contact
roller outer surface from the take-up roller rotational axis. In addition, in cases
of vibrations of the take-up roller 0 following an out-of-round rotation thereof,
and of resulting changes of the relative distance between the take-up and contact
rollers 0, 1, a damping effect and a minimization, if not even a disappearance, of
losses of contact between the take-up and contact rollers 0, 1 along their contact
line can be achieved by the continuous linear control of the pressure exerted by the
contact roller 1 towards the take-up roller 0 during the whole process of winding
up the polymer drawn by the stretching device to the take-up roller 0.
[0085] In another preferred embodiment of the invention shown in Figure 1, the process for
operating a contact roller 1 comprises providing a rocker arm 21 as the force transmission
means 20.
[0086] In the case where the direct gearless drive motor means 10 is mounted to a separate
stand 31, said rocker arm 21 is pivotably connecting a disk 22 driven by the direct
gearless drive motor means 10 rotationally around the motor axis 11 to the bearing
of the contact roller axis. By this preferred embodiment, the contact roller 1 is
moved towards, and away from, the take-up roller 0 or the bale 0' wound thereto so
as to apply a predetermined pressure to the polymer film 2 wound to the take-up roller
0. This embodiment of the process of the invention is shown in Figure 1.
[0087] In the case where the direct gearless drive motor means 10 is mounted to the journal
of the contact roller, or where two direct gearless drive motor means 10, 10 are mounted
to the journals of the contact roller 1, one rocker arm 21 is made pivotably connecting
one disk 22 driven by the motor means 10 rotationally around the motor axis 11, and
at least one fixation point at the separate stand 31, or two rocker arms 21, 21 are
made pivotably connecting two disks 22, 22 driven by two motor means 10, 10 rotationally
around the respective motor axes 11, 11, and at least one fixation point at the separate
stand 31. By this preferred embodiment, the contact roller 1 is moved towards, and
away from, the take-up roller 0 or the bale 0' wound thereto so as to apply a predetermined
pressure to the polymer film 2 wound to the take-up roller 0.
[0088] In other words, in accordance with this embodiment, the rotational movement driving
force of the motor around its axis 11 is transformed into a linear or translational
movement driving force by means of a mechanical transformation element which is the
rocker arm 21 proposed. The translational movement of the contact roller 1 initiated
by the rocker arm 21 is conducted on the linear guidance 30 also shown in Figure 1.
The directions of movement are shown in Figure 1 by the double-arrow 41.
[0089] In an even more preferred embodiment, the transformation of the rotational movement
driving force of the direct gearless-drive motor 10 into the linear or translational
movement driving force is effected around the top and bottom dead center positions
of the motor axis 11 towards the contact roller centre. The latter embodiment is advantageous,
since a relatively small rotational movement of the motor axis 11 transmits into a
relatively small translational movement of the force transmission means 20, especially
of the rocker arm 21, as shown in Figure 1. Thus, a sensitive movement of the contact
roller 1 towards, or away from, the take-up roller 0 may be achieved, resulting into
a similarly sensitive pressure application onto the polymer film 1 wound to the take-up
roller 0.
[0090] In an alternative and similarly preferred embodiment of the invention shown in Figure
2, the process for operating a contact roller 1 comprises providing a cograil 25 as
the force transmission means 20.
[0091] In the case where the direct gearless drive motor means 10 is mounted to a separate
stand 31, said cograil 21 is made pivotably connecting a cogwheel 26 driven by the
motor axis 11 rotationally to the bearing of the contact roller axis. By this preferred
embodiment, the contact roller 1 is moved towards, and away from, the take-up roller
0 or the bale 0' wound thereto so as to apply a predetermined pressure to the polymer
film 2 wound to the take-up roller 0. The directions of movement are shown in Figure
2 by the double-arrow 41.
[0092] In the case where the direct gearless drive motor means 10 is mounted to the journal
of the contact roller 1, or where two direct gearless drive motor means 10, 10 are
mounted to the journals of the contact roller 1, one cograil 25 is made pivotably
connecting one cogwheel 26 driven by the motor means 10 rotationally around the motor
axis 11, and at least one fixation point at the separate stand 31, or two cograils
25, 25 are made pivotably connecting two cogwheels 26, 26 driven by two motor means
10, 10 rotationally around the respective motor axes 11, 11, and at least one fixation
point at the separate stand 31. By this preferred embodiment, the contact roller 1
is moved towards, and away from, the take-up roller 0 or the bale 0' wound thereto
so as to apply a predetermined pressure to the polymer film 2 wound to the take-up
roller 0. The latter embodiment is shown in Figure 4.
[0093] In other words, in accordance with this embodiment, the rotational movement driving
force of the motor axis 11 is transformed into a linear or translational movement
driving force by means of a mechanical transformation element which is the cograil
25 proposed. The translational movement of the contact roller 1 initiated by the cograil
25 and initiated by the cogwheel 26 driven by the direct gearless-drive motor means
10 is effected on the linear guidance 30 also shown in Figures 2 and 4.
[0094] In an even more preferred embodiment, the transformation of the rotational movement
driving force of the direct gearless-drive motor 10 into the linear or translational
movement driving force is effected around the top and bottom dead center positions
of the motor axis 11 towards the contact roller centre. The latter embodiment is advantageous,
since a relatively small rotational movement of the motor axis 11 transmits into a
relatively small translational movement of the force transmission means 20, especially
of the cograil 25 as transmitted by the cogwheel 26, as shown in Figure 1. Thus, a
sensitive movement of the contact roller 1 towards, or away from, the take-up roller
0 may be achieved, resulting into a similarly sensitive pressure application onto
the polymer film 1 wound to the take-up roller 0. The directions of movement are shown
in Figures 2 and 4 by the double-arrow 41.
[0095] In accordance with an alternative of the present invention, the contact roller 1
may be provided to be in a pendulum-like arrangement with respect to the direct gearless-drive
motor means 10 of the present invention. This embodiment is exemplarily described
while referring to Figure 3 attached hereto.
[0096] In accordance with the present invention, a direct gearless-drive motor means 10
is provided for the purpose of keeping outer surface the contact roller 1 in a permanent
and uniform contact with the outer surface of the take-up roller 0 (if the latter
is empty and has not yet wound to it any polymer film material 2) or with the outer
surface of the bale 0' of polymer material already wound to the take-up roller 0,
while applying a predetermined pressure to the polymer film wound to the take-up roller
0. The motor means 10 is made exerting a rotational drive force around a motor axis
11. This is shown in the Figures by the double arrow 40: The force exerted may be
directed into both rotational directions.
[0097] In accordance with the present invention, the axis 11 of the direct gearless-drive
motor means 10 is made to be substantially parallel to the axes of the contact roller
1 and of the take-up roller 0.
[0098] Due to the fact that, despite the stationary position of the take-up roller axis,
the outer surface of the bale of polymer film material is changing its position permanently,
relative to the take-up roller axis, for example due to an increase of the bale diameter
with continuing winding of the polymer film to the take-up roller 0 or due to an out-of-round
rotation of the take-up roller 0 resulting from the polymer film 2 wound thereto,
the contact roller 1 must be made variable in its position relative to the take-up
roller axis. Simultaneously, a permanent application of a steady pressure to the polymer
film 2 by the contact roller is desired. This is achieved, in accordance with the
present invention, by making the direct gearless-drive motor means 10 capable of actuating
driving means by its rotational movement.
[0099] In this embodiment of the invention, said direct gearless-drive motor means 10 is
arranged above the contact roller 1. By such an arrangement, a smooth actuation of
a transmission means 20 by said motor means 10 may be achieved, resulting into transformation
of the rotational drive force exerted by the motor means 10 into a translational drive
force to the contact roller 1, whereby a movement of the contact roller 1 towards,
or away from, the take-up roller 0 is achieved.
[0100] In accordance with the present invention, the process for operating a contact roller
1 comprises providing a force transmission means 20 connected to and actuated by said
motor means 10. Said force transmission means 20 is made transforming, and in operation
actually transforms, the rotational drive force exerted by the axis 11 of the direct
gearless-drive motor means 10 into a translational drive force substantially perpendicular
to the motor axis 11. In accordance with the invention, said force transmission means
20 is made transmitting, and in operation actually transmits, said translational drive
force to the contact roller 1, thereby moving the contact roller 1 towards, or away
from, the take-up roller 0.
[0101] In another preferred embodiment of the invention not shown in the Figures, the process
for operating a contact roller 1 comprises providing a rocker arm 21 as the force
transmission means 20. Said rocker arm 21 is pivotably connecting a disk 22 driven
by the motor axis 11 rotationally above the contact roller 1 to the bearing of the
contact roller axis. By this preferred embodiment, the contact roller 1 is moved towards,
and away from, the take-up roller 0 or the bale 0' wound thereto so as to apply a
predetermined pressure to the polymer film 2 wound to the take-up roller 0.
[0102] In other words, in accordance with this embodiment, the rotational movement driving
force of the motor axis 11 is transformed into a linear or translational movement
driving force by means of a mechanical transformation element which is the rocker
arm 21 positioned above the contact roller 1. The translational movement of the contact
roller 1 initiated by the rocker arm 21 may occurs on the linear guidance 30. The
directions of movement are similar to those shown in Figure 1 by the double-arrow
41.
[0103] In a further preferred embodiment of the invention which is shown in Figure 3, the
process for operating a contact roller 1 comprises providing a pendulum arm 23 as
the force transmission means 20. The pendulum arm 23 is capable of pivotably connecting,
and in operation actually connects, the rotating motor axis 11 fixed at one end of
the pendulum arm 23 to the bearing of the contact roller axis pending at the other
end of the pendulum arm 23, thereby moving the contact roller 1 towards, and away
from, the take-up roller 0 or the bale 0' wound thereto in the direction of a circular
arc around the motor axis 11, as shown by the arrow 42 in Figure 3. As a result, a
predetermined pressure is applied, by the contact roller 1 swinging like a pendulum
around the direct gearless-drive motor means axis 11 in the shape of a circular arc,
to the polymer film 2 wound to the take-up roller 0.
[0104] In a further preferred embodiment of the invention, the process for operating a contact
roller 1 according to the invention, as described above in all details, comprises
providing a force transmission means 20, 21, 23, 25 which connects to each of the
journals of the axis of the contact roller 1. Such a preferable arrangement allows
a uniform application of the translational force to the contact roller 1 and, thereby,
of the contact roller 1 to the contact line of contact roller 1 and take-up roller
0 or bale of polymer film wound to the take-up roller 0.
[0105] The device and process of the present invention, due to their features, are highly
advantageous over the known devices and processes for operating contact rollers, particularly
the one described in the document
EP-B 1 423 318: The effect of using the direct gearless drive motor means 10 in combination with
the force transmission means 20 of this invention is particularly advantageous: A
substantial reduction, if not even a disappearance, of the cogging phenomenon can
be achieved by employing the direct gearless drive motor means 10. As a consequence,
a cogging-free actuation of the direct gearless drive motor's action may occur, into
both directions indicated in the Figures by the directional arrow 40. This cogging-free
actuation may lead to a continuous linear movement of the force transmission means
20 connected to the motor means 10 and, in turn, may result into a continuous linear
control of the pressure exerted by the contact roller 1 towards the take-up roller
0 at any distance between the contact roller outer surface from the take-up roller
rotational axis. In addition, in cases of vibrations of the take-up roller 0 following
an out-of-round rotation thereof, and of resulting changes of the relative distance
between the take-up and contact rollers 0, 1, a damping effect and a minimization,
if not even a disappearance, of losses of contact between the take-up and contact
rollers 0, 1 along their contact line can be achieved by the continuous linear control
of the pressure exerted by the contact roller 1 towards the take-up roller 0 during
the whole process of winding up the polymer drawn by the stretching device to the
take-up roller 0.
[0106] In addition, in cases where the contact roller unit in a plant may be variable in
distance to the take-up roller unit, the device of the present invention may be realized
easily: Only the contact roller is being moved as soon as any decrease of application
pressure of the polymer film to the take-up roller occurs, e.g. as a result of an
out-of-round rotation of the take-up roller or of vibrations occurring during winding
the polymer film. In addition, an increasing diameter of the bale of wound polymer
film to the take-up roller does not require any adaptation of the position of the
contact roller which is not compensated by the direct gearless-drive motor means in
co-operation with the force transmission means actuated by said direct gearless drive
motor means without the undesired cogging phenomenon.
[0107] Furthermore, the direct gearless-drive motor means allows short distances of movement
of the contact roller, resulting into a substantial reduction of the mass of the driving
unit. Moreover, there could be experienced surprisingly a decreasing influence of
the reduced mass acceleration onto reduced vibrations in the course of operating the
winding process.
[0108] The invention was described above in detail while referring to its preferred embodiments.
The reference to the preferred embodiments should, however, not be understood as a
limitation of the invention. Quite to the contrary: The scope of the invention is
only determined by the claims which follow.
List of reference numerals
[0109]
- 0
- take-up roller
- 0'
- bale of polymer film material wound to the contact roller
- 1
- contact roller
- 2
- polymer film
- 10
- direct gearless drive motor means
- 11
- motor axis
- 20
- force transmission means
- 21
- rocker arm
- 22
- disk
- 23
- pendulum arm
- 25
- cograil
- 26
- cogwheel
- 30
- linear guidance
- 31
- stand for a fixation of a motor means or cograil/rocker arm
- 40
- arrow showing the directions of the motor's rotational drive force
- 41
- arrow showing the directions of movement of the contact roller
- 42
- arrow showing the directions of circular arc movement of the contact roller
1. A device for operating at least one contact roller (1) in contact with a take-up roller
(0) or with a polymer film bale (0') wound to the take-up roller (0), preferably in
a plant for stretching a polymer film which is, after the stretching step, wound to
said take-up roller (0) rotatable around a rotational axis, said at least one contact
roller (1) being rotatable around a rotational axis arranged parallel to the take-up
roller's rotational axis, being supported movably by variable distances perpendicular
relative to the take-up roller's rotational axis and providing for a permanent application
of a predetermined pressure to the polymer film (2) during said winding to the take-up
roller or polymer film bale (0') along a contact line being parallel to the axes of
the take-up and contact rollers (0, 1) and on the surface of the contact roller (1)
and take-up roller (0) or polymer film bale (0'), said device comprising
- at least one direct gearless-drive motor means (10) for exerting a rotational drive
force around a motor axis (11);
- said motor axis (11) being substantially parallel to the axes of the contact and
take-up rollers (0, 1) and being capable of actuating force transmission means (20)
by its rotational movement;
- said force transmission means (20) being connected to and actuated by said at least
one motor means (10) and transforming the rotational drive force exerted by the axis
(11) of the at least one direct gearless-drive motor means (10) into a translational
drive force substantially perpendicular to the motor axis (11);
- said force transmission means (20) being capable of transmitting said translational
drive force to the contact roller (1), thereby moving the contact roller (1) towards,
or away from, the take-up roller (0).
2. The device for operating at least one contact roller (1) according to claim 1, wherein
said contact roller (1) is guided, in the directions of the translational drive force,
by at least one linear guidance (30).
3. The device for operating at least one contact roller (1) according to claim 1 or claim
2, wherein the at least one direct gearless-drive motor means (10), preferably one
direct gearless-drive motor means (10), is mounted to a separate stand (31) in operational
distance to the contact roller (1); or wherein the at least one direct gearless-drive
motor means (10), preferably two direct gearless-drive motor means (10), is/are mounted
to the journal(s) of the contact roller (1) in operational distance to a separate
stand (31).
4. The device for operating at least one contact roller (1) according to any of the claims
1 to 3, wherein said force transmission means (20) is a rocker arm (21) pivotably
connecting a disk (22) driven by separate stand-mounted direct gearless drive motor
means (10) rotationally around the motor axis (11) and the bearing of the contact
roller axis, thereby being capable of moving the contact roller (1) towards, and away
from, the take-up roller (0) or the bale (0') wound thereto so as to apply a predetermined
pressure to the polymer film (2) wound to the take-up roller (0); or wherein said
force transmission means (20) is a rocker arm (21) pivotably connecting a disk (22)
driven by contact roller journal-mounted direct gearless drive motor means (10) rotationally
around the motor axis (11) and at least one fixation point at the separate stand (31),
thereby being capable of moving the contact roller (1) towards, and away from, the
take-up roller (0) or the bale (0') wound thereto so as to apply a predetermined pressure
to the polymer film (2) wound to the take-up roller (0).
5. The device for operating at least one contact roller (1) according to any of the claims
1 to 3, wherein said force transmission means (20) is a cograil (25) connecting a
cogwheel (26) driven by separate stand-mounted direct gearless drive motor means (10)
rotationally around the motor axis (11) and the bearing of the contact roller axis,
thereby being capable of moving the contact roller (1) towards, and away from, the
take-up roller (0) or the bale (0') wound thereto so as to apply a predetermined pressure
to the polymer film (2) wound to the take-up roller (0); or wherein said force transmission
means (20) is a cograil (25) connecting a cogwheel (26) driven by contact roller journal-mounted
direct gearless drive motor means (10) rotationally around the motor axis (11) and
at least one fixation point at the separate stand (31), thereby being capable of moving
the contact roller (1) towards, and away from, the take-up roller (0) or the bale
(0') wound thereto so as to apply a predetermined pressure to the polymer film (2)
wound to the take-up roller (0).
6. A device for operating at least one contact roller (1) in contact with a take-up roller
(0) or with a polymer film bale (0') wound to the take-up roller (0), preferably in
a plant for stretching a polymer film which is, after the stretching step, wound to
said take-up roller (0), rotatable around a rotational axis, said at least one contact
roller (1) being rotatable around a rotational axis arranged parallel to the take-up
roller's rotational axis, being supported movably by variable distances perpendicular
relative to the take-up roller's rotational axis and providing for a permanent application
of a predetermined pressure to the polymer film (2) during said winding to the take-up
roller or polymer film bale (0') along a contact line being parallel to the axes of
the take-up and contact rollers (0, 1) and on the surface of the contact roller (1)
and take-up roller (0) or polymer film bale (0'), said device comprising
- at least one direct gearless-drive motor means (10) for exerting a rotational drive
force around a motor axis (11);
- said motor axis (11) being substantially parallel to the axes of the contact and
take-up rollers (0, 1) and being capable of actuating force transmission means (20)
by its rotational movement;
- said direct gearless-drive motor means (10) being arranged above or below said contact
roller (1);
- said force transmission means (20) connected to and actuated by said direct gearless
drive motor means (10) and transforming the rotational drive force exerted by the
axis (11) of the direct gearless-drive motor means (10) into a translational drive
force in the direction of a circular arc around the motor axis (11);
- said force transmission means (20) being capable of transmitting said translational
drive force to the contact roller (1), thereby moving the contact roller (1) towards,
or away from, the take-up roller (0).
7. The device for operating at least one contact roller (1) according to claim 6, wherein
said force transmission means (20) is a rocker arm (21) pivotably connecting the rotating
motor axis (11) and the bearing of the contact roller axis, thereby moving the contact
roller (1) towards, and away from, the take-up roller (0) or the bale (0') wound thereto
so as to apply a predetermined pressure to the polymer film (2) wound to the take-up
roller (0).
8. The device for operating at least one contact roller (1) according to claim 6, wherein
said force transmission means (20) is a pendulum arm (23) pivotably connecting the
rotating motor axis (11) fixed at one end of the pendulum arm (23) and the bearing
of the contact roller axis pending at the other end of the pendulum arm (23), thereby
moving the contact roller (1) towards, and away from, the take-up roller (0) or the
bale (0') wound thereto so as to apply a predetermined pressure to the polymer film
(2) wound to the take-up roller (0).
9. The device for operating at least one contact roller (1) according to any of the claims
1 to 8, wherein said force transmission means (20, 21, 23, 25) connects to each of
the journals of the axis of the contact roller (1), thereby allowing a uniform application
of the translational force to the contact roller (1) and, thereby, of the contact
roller (1) to the contact line of contact roller (1) and take-up roller (0) or bale
of polymer film wound to the take-up roller (0).
10. A process for operating at least one contact roller (1) in contact with a take-up
roller (0) or with a polymer film bale (0') wound to the take-up roller (0), preferably
in a plant for stretching a polymer film which is, after the stretching step, wound
to said take-up roller (0) rotatable around a rotational axis, said at least one contact
roller (1) being rotatable around a rotational axis arranged parallel to the take-up
roller's rotational axis and being supported movably by variable distances perpendicular
relative to the take-up roller's rotational axis, wherein a predetermined pressure
is applied permanently to the polymer film (2) by said contact roller (1) during said
winding to the take-up roller or polymer film bale (0') along a contact line being
parallel to the axes of the take-up and contact rollers (0, 1) and on the surface
of the contact roller (1) and take-up roller (0) or polymer film bale, said process
comprising
- providing at least one direct gearless-drive motor means (10) for exerting a rotational
drive force around a motor axis (11);
- adjusting the direction of said motor axis (11) to be substantially parallel to
the axes of the contact and take-up rollers (0, 1) and making the direct gearless
drive motor means (10) capable of actuating a force transmission means (20) by its
rotational movement;
- providing said force transmission means (20) connected to and actuated by said motor
means (10), said force transmission means (20) transforming the rotational drive force
exerted by the direct gearless drive motor means (10) around the axis (11) of the
direct gearless-drive motor means (10) into a translational drive force substantially
perpendicular to the motor axis (11); and
- allowing said force transmission means (20) to transmit said translational drive
force to the contact roller (1), thereby moving the contact roller (1) towards, or
away from, the take-up roller (0).
11. The process according to claim 10, said process comprising guiding said contact roller
(1) in the directions of the translational drive force by at least one linear guidance
(30).
12. The process according to claim 10 or claim 11, either comprising the steps of mounting
the at least one direct gearless-drive motor means (10), preferably one direct gearless-drive
motor means (10), to a separate stand (31) in operational distance to the contact
roller (1); or the step of mounting the at least one direct gearless-drive motor means
(10), preferably two direct gearless-drive motor means (10), to the journal(s) of
the contact roller (1) in operational distance to a separate stand (31).
13. The process according to any of the claims 10 to 12, said process comprising a step
of providing, as said force transmission means (20), a rocker arm (21) pivotably connecting
a disk (22) driven by separate stand-mounted direct gearless drive motor means (10)
rotationally around the motor axis (11) and the bearing of the contact roller axis,
thereby being capable of moving the contact roller (1) towards, and away from, the
take-up roller (0) or the bale (0') wound thereto so as to apply a predetermined pressure
to the polymer film (2) wound to the take-up roller (0); or said process comprising
a step of providing, as said force transmission means (20), a rocker arm (21) pivotably
connecting a disk (22) driven by contact roller journal-mounted direct gearless drive
motor means (10) rotationally around the motor axis (11) and at least one fixation
point at the separate stand (31), thereby being capable of moving the contact roller
(1) towards, and away from, the take-up roller (0) or the bale (0') wound thereto
so as to apply a predetermined pressure to the polymer film (2) wound to the take-up
roller (0).
14. The process according to any of the claims 10 to 12, said process comprising a step
of providing, as said force transmission means (20), a cograil (25) connecting a cogwheel
(26) driven by separate stand-mounted direct gearless-drive motor means (10) rotationally
around the motor axis (11) and the bearing of the contact roller axis, thereby being
capable of moving the contact roller (1) towards, and away from, the take-up roller
(0) or the bale (0') wound thereto so as to apply a predetermined pressure to the
polymer film (2) wound to the take-up roller (0); or said process comprising a step
of providing, as said force transmission means (20), a cograil (25) connecting a cogwheel
(26) driven by contact roller journal-mounted direct gearless-drive motor means (10)
rotationally around the motor axis (11) and at least one fixation point at the separate
stand (31), thereby being capable of moving the contact roller (1) towards, and away
from, the take-up roller (0) or the bale (0') wound thereto so as to apply a predetermined
pressure to the polymer film (2) wound to the take-up roller (0).
15. A process for operating at least one contact roller (1) in contact with a take-up
roller (0) or with a polymer film bale (0') wound to the take-up roller (0), preferably
in a plant for stretching a polymer film which is, after the stretching step, wound
to said take-up roller (0) rotatable around a rotational axis, said at least one contact
roller (1) being rotatable around a rotational axis arranged parallel to the take-up
roller's rotational axis and being supported movably by variable distances perpendicular
relative to the take-up roller's rotational axis, wherein a predetermined pressure
is applied permanently to the polymer film (2) by said contact roller (1) during said
winding to the take-up roller or polymer film bale (0') along a contact line being
parallel to the axes of the take-up and contact rollers (0, 1) and on the surface
of the contact roller (1) and take-up roller (0) or polymer film bale, said process
comprising
- providing at least one direct gearless-drive motor means (10) for exerting a rotational
drive force around a motor axis (11);
- adjusting the direction of said motor axis (11) to be substantially parallel to
the axes of the contact and take-up rollers (0, 1) and making the direct gearless
drive motor means (10) capable of actuating a force transmission means (20) by its
rotational movement;
- providing said direct gearless-drive motor means (10) to be arranged above said
contact roller (1);
- providing said force transmission means (20) connected to and actuated by said direct
gearless drive motor means (10), said force transmission means (20) transforming the
rotational drive force exerted by the axis (11) of the direct gearless-drive motor
means (10) into a translational drive force in the direction of a circular arc around
the motor axis (11); and
- allowing said force transmission means (20) to transmit said translational drive
force to the contact roller (1), thereby moving the contact roller (1) towards, or
away from, the take-up roller (0).
16. The process according to claim 15, said process comprising providing, as said force
transmission means (20), a rocker arm (21) pivotably connecting the rotating motor
axis (11) and the bearing of the contact roller axis, thereby moving the contact roller
(1) towards, and away from, the take-up roller (0) or the bale (0') wound thereto
so as to apply a predetermined pressure to the polymer film (2) wound to the take-up
roller (0).
17. The process according to claim 15, said process comprising providing, as said force
transmission means (20), a pendulum arm (23) pivotably connecting the rotating motor
axis (11) fixed at one end of the pendulum arm (23) and the bearing of the contact
roller axis pending at the other end of the pendulum arm (23), thereby moving the
contact roller (1) towards, and away from, the take-up roller (0) or the bale (0')
wound thereto so as to apply a predetermined pressure to the polymer film (2) wound
to the take-up roller (0).
18. The process according to any of the claims 10 to 17, additionally providing connecting
said force transmission means (20, 21, 23, 25) to each of the journals of the axis
of the contact roller (1), thereby allowing a uniform application of the translational
force to the contact roller (1) and, thereby, of the contact roller (1) to the contact
line of contact roller (1) and take-up roller (0) or bale of polymer film wound to
the take-up roller (0).