[0001] The present invention regards a process for controlled collection of continuous strip-like
elements for building tyres. The invention also regards a production line that actuates
the aforesaid process.
[0002] In building tyres, the use of elementary semi-finished products obtained from continuous
strip-like elements is normally required; such elements comprise textile cords and/or
metallic cords that are mutually parallel and incorporated in at least one layer of
raw elastomeric material.
[0003] By way of example, this type of strip-like manufactured item can be cut into pieces
to form strip-like elements to be employed in the manufacturing of a carcass ply,
of a belt layer, or of another component of the tyre. As an alternative, a continuous
strip-like element can be wound into coils disposed in side by side relationship around
the circumferential extension of a tyre being processed, to form a reinforcement layer.
[0004] The manufacturing of the continuous strip-like elements normally takes place by means
of a continuous process, starting from cords drawn from respective packages. The cords
- whose number normally equals a multiple of the quantity provided in a single continuous
strip-like element - are guided along paths converging towards a rubberizing unit.
At the rubberizing unit, at least one layer of raw elastomeric material is applied
on the set of cords disposed in a coplanar manner, so as to obtain a continuous rubberized
band. The continuous rubberized band exiting from the rubberizing unit is conducted
through a cutting unit comprising one or more knives which divide the band itself
into two or more continuous strip-like elements.
[0005] In order to facilitate the mutual separation thereof, the continuous strip-like elements
are moved away from the cutting unit along mutually diverging trajectories by means
of suitable drift rollers, before being conducted to respective collection stations.
[0006] An exemplary embodiment of a known cutting unit is disclosed by
JP S60-202057 A, wherein a rubber-coated steel cord cloth, unwound from a stock roll, is fed to a
cutting device through plural guide rollers. The cloth is cut in the cutting device
in two parts on both sides to convey the cut parts by means of a driving means, and
the cut parts are respectively wound around winding rolls. The positions of the both
sides of the cloth are controlled with the aid of guide rollers. The guide rollers
on the side parts are configured such that the position may be adjusted by an adjustment
handle according to the width of the rubberized steel cord fabric.
[0007] EP 0467268 A2 specifically address a numerically controlled slitter (NC slitter). This NC slitter
has a plurality of slitting knife units. Each slitting knife unit has a lower knife
unit and an upper knife unit. The lower knife of the lower knife unit is rotated by
a belt. The upper knife is rotated to be driven in pressure contact with the lower
knife. Endless steel belts are provided to move the respective upper knife units and
lower knife units in a desired direction for altering the slitted width of a sheet
material such as paper or the like.
[0008] GB 948,047 refers to a remotely controlled slitter system which comprises a slitter blade which
is supported from above a paper web and which shearingly engages a slitter band supported
from below the paper web. To shift the position of the blade, a knob may be rotated
in one direction or the other. A pinion is then rotated in the proper direction to
move the blade to a position corresponding to the set position of the knob.
US 4,386,273 relates to a slitter assembly including a cutter blade which is placed in cutting
engagement with a belt, so that the belt is continuously trimmed to the desired width,
the remaining trimmed longitudinal portion having a varying width. The desired width
is obtained by using a movable positioning means, the movement of which is controlled
by a conventional servomechanism drive means including a fluid-actuated cylinder.
[0009] EP 0309818 A2 relates to an apparatus for continuously separating a web of material into at least
two web parts, comprising a severing unit consisting of a circular severing knife
and of a backing roller, over the circumference of which the web of material is guided.
The relative position of the web of material and of the part webs is monitored by
sensing members. Variations in the relative position of the running web of material
are recorded by this edge-sensing member and converted into a control signal for the
web-adjusting member. The web-adjusting member intended for the individual web of
material consists of two deflecting rollers arranged at a distance from one another.
[0010] GB 2 071 060 A relates to a deviator device for webs, particularly paper webs, comprising an inlet
guide surface and an outlet guide surface for said web. A deviator drum is mounted
rotatable about a first axis and disposed between said inlet surface and outlet surface,
said web winding in contact with part of the periphery of said drum when in use. Adjustable
support means are provided for varying the positions of said first axis about a second
axis perpendicular to the first axis and tangential both to said drum and to said
inlet surface.
[0011] In order to meet the productivity needs of modern plants, the Applicant has studied
the dynamic behaviour of semi-finished products in continuous band form translating
at high speed along the production line.
[0012] The Applicant has thus been able to observe that, due to various factors that are
hard to identify and control, the continuous band coming from the rubberizing unit
occasionally carries out slight lateral movements during the advancement towards the
cutting unit.
[0013] In high speed conditions, these movements tend to significantly alter the trajectory
completed by the continuous strip-like elements translating away from the knives,
with the risk of consequent breakage and interruption of the manufacturing cycle.
[0014] The Applicant has observed that an accurate control of these trajectories, in response
to the occasional movements of the continuous band, can lead to significant improvements
of the state of the art, particularly in terms of productivity and final product quality.
[0015] The Applicant has perceived the manner of actuating the abovementioned control, by
means of timely operations of restoration of the dynamic equilibrium of the lateral
thrusts induced on the continuous strip-like elements translating away from the knives
in the region of generation of the strip-like elements themselves.
[0016] More precisely, the Applicant has found that the execution of the restoration operations
by means of drive members situated outside the region of generation of the continuous
strip-like elements allows actuating an accurate control without interruption or decrease
of productivity.
[0017] More particularly, according to a first aspect the invention regards a process for
controlled collection of continuous strip-like elements for building tyres, according
to claim 1.
[0018] The Applicant deems that it is thus possible to increase the productivity along the
production line of the continuous strip-like elements, without having to use sophisticated
systems for inhibiting occasional lateral movements of the continuous band that advances
at high speed towards the cutting unit.
[0019] By modulating the drift forces in the above-described manner, possible deviations
of the trajectories completed by the continuous strip-like elements translating away
from the knives are quickly corrected, without it being necessary to stop or slow
down the production to execute the required corrections. The production lines can
therefore always be utilised at maximum productivity, even during modulation operations.
The generation of the drift forces can be attained by means of structurally simple,
inexpensive and highly reliable components.
[0020] A precise execution of the cutting is also facilitated, due to a correction of the
relative positioning between the knives and the continuous band following undesired
transverse movements of the latter.
[0021] It is also possible to restore the correct execution of the cutting in case of malfunctioning.
[0022] The correction of the relative positioning between the continuous band and the knives
is attainable with simple and reliable equipment.
[0023] In a second aspect, the invention regards a production line for controlled collection
of continuous strip-like elements for building tyres, according to claim 6.
[0024] In at least one of the aforesaid aspects, one or more of the following preferred
embodiment solutions can also be employed.
[0025] Preferably, the action of modulating the drift forces is carried out in response
to transverse movements carried out by the continuous band.
[0026] It is thus possible to optimise the quality of the processing without it being necessary
to guide the alignment of the continuous band advancing towards the knives with extreme
precision.
[0027] In said generation region, at least one first deviation from the lying plane of the
continuous band is preferably imposed to the continuous strip-like elements.
[0028] It is thus possible to move the continuous strip-like elements away from the knives
immediately after the execution of the cutting and arrange more space for the housing
of the guiding devices.
[0029] In the generation region, a second deviation directed laterally relative to the longitudinal
extension direction of the continuous band can also be imposed to each continuous
strip-like element.
[0030] This lateral deviation causes the desired spreading apart of the trajectories of
the continuous strip-like elements along respectively diverging trajectories. Preferably
the first and the second deviations can be imposed simultaneously.
[0031] In the generation region, at least one third deviation towards a lying plane of the
continuous band can also be imposed to the continuous strip-like elements.
[0032] Preferably the continuous strip-like elements, following the third deviation, are
brought into mutual-coplanarity relationship.
[0033] The continuous strip-like elements, disposed in a coplanar manner with respect to
each other and laterally separated from each other, are thus adapted to be simultaneously
engaged by a drive unit and to be conducted to successive treatments stations along
the production line.
[0034] More particularly, the action of modulating the drift forces can be carried out by
rotating at least one of said drift rollers around a correction axis perpendicular
to a rotation axis thereof.
[0035] It is thus possible to control the intensity of the drift forces with simple, inexpensive
and highly reliable components.
[0036] The action of modulating the drift forces can be carried out in response to a notification
signal.
[0037] Thus, the timeliness of operation is facilitated for the purpose of correcting the
drift forces.
[0038] More particularly, the following actions can be provided for: comparing the position
of a diverging stretch of at least one of said n continuous strip-like elements relative
to a preset theoretical reference position; and emitting a notification signal when
the difference between the position of the diverging stretch and the theoretical reference
position exceeds a predetermined tolerance threshold.
[0039] In such a manner, a constant control of the correct position of the continuous strip-like
elements is attained, facilitating timely correction operations.
[0040] The cutting action can be preferably executed simultaneously along the respectively
opposite edges of the continuous band in order to generate pairs of continuous strip-like
elements.
[0041] Preferably, said pairs of continuous strip-like elements are generated in succession
starting from outer side edges of the continuous band.
[0042] In such a manner, an effective generation and separation of the continuous strip-like
elements from the continuous band is attained.
[0043] Preferably the action of translating the carriage takes place by effect of transverse
thrust forces induced by transverse movements of the continuous band.
[0044] In such a manner, a structural and functional simplification of the system is obtained,
due to a spontaneous alignment of the knives with respect to the continuous band.
[0045] The transverse movements can be preferably actuated by means of an actuating arm
that is disengaged from the cutting unit when correction has occurred.
[0046] A precise execution of the cutting is thus facilitated. Indeed, the cutting unit
disengaged from the actuating arm is facilitated in following the spontaneous transverse
movements of the continuous band.
[0047] The action of feeding said continuous band can preferably comprise: feeding continuous
reinforcing cords longitudinally translating through an extrusion die; applying at
least one raw elastomeric layer onto the continuous reinforcing cords translating
through the extrusion die.
[0048] Preferably each continuous strip-like element is collected on a respective reel separately
from the other continuous strip-like elements.
[0049] Preferably said continuous band is fed at a speed included between about 1 m/s and
about 3 m/s.
[0050] Still more preferably said continuous band is fed at a speed included between about
1.5 m/s and about 2.5 m/s. The guiding devices preferably impose, to said continuous
strip-like elements, at least one first deviation from the lying plane of the continuous
band. The guiding devices preferably impose, to said continuous strip-like elements,
at least one second deviation directed laterally relative to the longitudinal extension
direction of the continuous band. Preferably the guiding devices impose, to said continuous
strip-like elements, at least one third deviation towards a lying plane of the continuous
band. The continuous strip-like elements, following the third deviation, are preferably
brought into mutual-coplanarity relationship.
[0051] The guiding devices preferably comprise drift rollers, provided for operating in
contact relationship with said continuous strip-like elements.
[0052] Preferably each drift roller can have an operative surface with convex profile operating
in contact relationship on the respective continuous strip-like element.
[0053] Preferably, each drift roller is rotatably idle.
[0054] Each drift roller is rotatably supported according to a rotation axis inclined to
a direction perpendicular to a longitudinal extension direction of a stretch of the
continuous strip-like element upstream of the drift roller itself.
[0055] Such inclination facilitates the generation of the desired drift forces.
[0056] For each continuous strip-like element produced by the cutting unit, at least two
drift rollers are preferably provided which are mutually aligned along a trajectory
diverging from a longitudinal mid-line of the continuous band.
[0057] Each drift roller is preferably positionable around a correction axis perpendicular
to a rotation axis thereof.
[0058] In a preferred embodiment, each drift roller is rotatably supported by a rod around
said correction axis.
[0059] The adjustment devices preferably comprise a transmission lever operating on said
rod.
[0060] The transmission lever comprises a lever radially projecting with respect to the
correction axis and a drive arm constrained to the lever.
[0061] The drive members preferably comprise a first threaded element rotatably supported
externally of said generation region.
[0062] Thus, excellent accuracy can be attained in regulating the intensity of the drift
forces, since high angular rotations of the first threaded element correspond with
micrometric movements of the drift roller around the correction axis.
[0063] The first threaded element can be operatively engaged with a second threaded element
carried by the drive arm. The first threaded element is preferably engaged with a
support structure of the cutting unit. The entire transmission lever is thus extraneous
and immune to possible transverse movements induced to the cutting unit with respect
to the support structure.
[0064] Signalling devices can also be provided for emitting a notification signal when the
position of a diverging stretch of at least one continuous strip-like element exceeds
a predetermined tolerance threshold.
[0065] In one embodiment, the following can be provided: sensor members for detecting the
position of a diverging stretch of at least one continuous strip-like element; and
a comparator for comparing the position detected by the sensor members with a preset
theoretical reference position.
[0066] In a preferred embodiment, at least one actuator can be provided, acting on each
first threaded element for automatically adjusting the orientation of the corresponding
drift roller around the aforesaid correction axis following an output signal of an
electronic control unit.
[0067] Said knives are preferably distributed in respective pairs, mutually spaced along
a longitudinal translation direction of the continuous band.
[0068] The knives of each pair are symmetrically disposed relative to a longitudinal mid-line
of the continuous band.
[0069] The knives are distributed so as to define a V-shaped configuration with vertex facing
the collection unit. The knives are preferably carried by a carriage movable in a
direction transverse to the feeding direction of the continuous band.
[0070] Preferably the knives are removably fixed on a support block removably fixed to the
carriage.
[0071] Preferably the support block is positioned along a direction substantially parallel
to the extension of a cutting edge of each knife.
[0072] The cutting unit can preferably comprise a centring guide operatively engaging the
continuous band for maintaining a centred positioning of the latter relative to said
knives.
[0073] Preferably the centring guide has a passage opening having width equal to the width
of the continuous band. The centring guide is preferably fixed with respect to the
cutting unit.
[0074] Thrust devices are provided for imposing transverse movements to the knives.
[0075] The thrust devices are actuatable from outside said generation region.
[0076] The thrust devices comprise an actuating arm acting on the cutting unit.
[0077] In a preferred embodiment, the actuating arm is carried by a bar that is axially
movable for imposing a transverse movement to the cutting unit.
[0078] The bar is preferably rotatable around a longitudinal axis thereof for disengaging
the actuating arm from the cutting unit.
[0079] The band feeding devices can preferably comprise: devices for feeding elastomeric
material to an extrusion die; devices for feeding, to the extrusion die, said reinforcing
cords that are arranged parallel and adjacent to each other.
[0080] The collection unit comprises a plurality of reels, each dedicated to the winding
of a respective continuous strip-like element.
[0081] Further characteristics and advantages will be clearer from the detailed but not
exclusive description of a preferred embodiment of a process and a production line
for controlled collection of continuous strip-like elements for building tyres, according
with the present invention. Such description will be set forth hereinbelow with reference
to the enclosed drawings, provided only as a non-limiting example, in which:
- figure 1 schematically shows, in plan view, a production line obtained in accordance
with the present invention;
- figure 2 shows a detail of the production line in top view, highlighting a transition
zone circumscribing the cutting unit;
- figure 3 shows a detail of figure 2 in side view;
- figure 4 shows the cutting unit in perspective view;
- figure 5 shows, in interrupted perspective view, a continuous strip-like element obtainable
by means of the present invention.
[0082] With reference to the abovementioned figures, the reference number 1 was used to
indicate a production line for controlled collection of continuous strip-like elements
for building tyres, according to the present invention.
[0083] The production line 1 is provided to obtain and collect a plurality of continuous
strip-like elements 2, of which one is represented in detail in figure 5, comprising
a plurality of reinforcing cords 3, e.g. made of textile, synthetic and/or metallic
material. The reinforcing cords 3 are extended parallel to each other, along a longitudinal
extension direction of the continuous strip-like element 2, preferably in mutual-coplanarity
relationship.
[0084] The reinforcing cords 3 are incorporated in or covered by at least one layer of raw
elastomeric material 4. Each continuous strip-like element 2 is adapted to be used
for the purpose of building tyres for vehicle wheels. For example, each continuous
strip-like element 2 can for such purpose be cut into pieces of predetermined length,
to be used for obtaining carcass plies, belt layers or other components of a tyre
being manufactured.
[0085] The production line 1 comprises band feeding devices 5 that supply a continuous band
6 of elastomeric material, comprising said reinforcing cords 3, preferably but not
necessarily in a quantity equal to a multiple of a predetermined number of cords present
in each of the continuous strip-like elements 2 during manufacturing. The band feeding
devices 5 comprise cord feeding devices 7 which feed the reinforcing cords 3. The
cord feeding devices 7 can for example comprise at least one creel 8 which sustains
a plurality of packages 8a; from each of the latter, one of the reinforcing cords
3 is drawn to be used for the purpose of forming the continuous strip-like elements
2.
[0086] The reinforcing cords 3 coming from the creel 8 are conducted along paths mutually
converging towards an extruder 9 fed with raw elastomeric material. It is preferably
provided that the reinforcing cords 3 traverse at least one guide element, for example
a comb element, in proximity to an extrusion die 10 in which the elastomeric material
flows. The elastomeric material is preferably fed to the extrusion die 10 by means
of feed devices comprising, for example, a extruder and/or a gear pump 11. The elastomeric
material can reach the gear pump 11 upon action of a worm screw operatively housed
in the extruder 9, upstream of the gear pump itself.
[0087] Inside the extrusion die 10, the raw elastomeric material is applied onto the reinforcing
cords 3 longitudinally translating through the die itself. The reinforcing cords 3
exit from the extrusion die 10 along mutually parallel and coplanar trajectories;
the cords 3 are covered with the layer 4 formed by the raw elastomeric material with
which they have come into contact, to form the aforesaid continuous band 6.
[0088] The continuous band 6 can be subjected to the action of a tensioning unit 12, which
drives the reinforcing cords 3 and the elastomeric material through the extrusion
die 10 as a result of a traction action applied to the continuous band itself.
[0089] At the tensioning unit 12 or in a zone upstream and/or downstream thereof, a cooling
action can also be carried out for the continuous band 6 exiting from the extrusion
die 10. The cooling action allows carrying out a suitable structural consolidation
of the raw elastomeric material and of the continuous band 6 in its entirety. Downstream
of the tensioning unit 12, a storage unit 13 can be provided that defines a winding
circuit capable of storing a section of suitable length of the continuous band 6 coming
from the tensioning unit 12.
[0090] In a
per se known manner and hence not further described herein, the winding circuit defined
in the storage unit 13 has a length that can be modulated in response to possible
variations of productivity of the continuous band 6 by the band feeding devices 5,
and/or to varied requirements of continuous band 6 downstream of the same storage
unit 13. Thus, a process continuity is facilitated even in the presence of variations
or temporary interruptions of productivity in portions of the production line 1 respectively
downstream and upstream of the same storage unit 13.
[0091] Preferably the continuous band 6 is fed at a speed included between about 1 m/s and
about 3 m/s.
[0092] Still more preferably said continuous band 6 is fed at a speed included between about
1.5 m/s and about 2.5 m/s.
[0093] A "region of generation" "Z" of continuous strip-like elements 2 comprises a cutting
unit 14, and guiding devices 28.
[0094] Preferably said generation region "Z" is obtained in a space with prismatic conformation.
[0095] Preferably said generation region "Z" comprises at least a part of adjustment devices
30.
[0096] Said generation region "Z" nevertheless does not include drive devices 33, and possibly
at least one portion of a support structure 23 engaging the drive devices themselves.
[0097] Cutting unit 14, guiding devices 28, adjustment devices 30, drive devices 33 and
support structure 23 are more precisely described hereinbelow.
[0098] Preferably downstream of the storage unit 13, said cutting unit 14 slidably engages
the continuous band 6 in order to divide it into a plurality of continuous strip-like
elements 2, each comprising a predetermined number of reinforcing cords 3.
[0099] A drive unit 15 situated downstream of the cutting unit 14 operates on each of the
continuous strip-like elements 2 for assuring the successive movement thereof to the
cutting unit 14 itself.
[0100] Downstream of the drive unit 15, the continuous strip-like elements 2 are collected
separately from each other by means of at least one collection unit 16, which in a
preferred solution comprises a plurality of reels 17 each dedicated to the winding
of a respective continuous strip-like element 2.
[0101] The cutting unit 14 comprises n knives 18 carried by a carriage 19 and operating
through the continuous band 6 for generating n+1 continuous strip-like elements 2
therefrom.
[0102] The knives 18 are preferably distributed on one or more pairs, mutually spaced along
a longitudinal translation direction "F" of the continuous band 6, preferably defining
a V-shaped configuration with vertex facing the collection unit 16.
[0103] Preferably the knives 18 of each pair are symmetrically disposed relative to a longitudinal
mid-line "L" of the continuous band 6.
[0104] In a preferred embodiment, a central knife 18 can be disposed at a vertex of the
V-shaped configuration, in order to operate along the longitudinal mid-line "L" of
the continuous band 6.
[0105] It is thus conveniently possible to carry out the cutting action simultaneously along
the respectively opposite edges of the continuous band 6, in order to form pairs of
continuous strip-like elements 2. Conveniently, the pairs of continuous strip-like
elements 2 are generated in succession starting from outer side edges of the continuous
band 6 itself.
[0106] In a different preferred embodiment (not shown), at the vertex of the V-shaped configuration,
a pair of knives 18 is provided. In such embodiment solution, the continuous strip-like
element 2 that comes to be generated in central position continues straight and the
cutting unit 14 gives rise - with its own action - to an odd number of continuous
strip-like elements 2, in a number equal to 2n + 1 where n is the number of pairs
of knives 18 employed.
[0107] Preferably, the knives 18 are individually and removably fixed to respective abutment
seats 20 provided on the carriage 19, each by means of a respective knife locking
member 20a. The abutment seats 20 can be conveniently obtained on a support block
21 removably fixed to the carriage 19 by means of a block locking member 22, and positionable
along a direction substantially parallel to the extension of a cutting edge 18a of
each knife 18. By adjusting the position of the support block 21, it is therefore
possible to simultaneously move all the knives 18, along the respective cutting edges
18a, and arrange them in different positions relative to a lying plane "P" of the
continuous band 6, so that different portions of the cutting edge 18a of each knife
18 are successively placed in interference relationship with the advancement of the
continuous band itself. In other words, it is possible to modify the position of the
knives 18 in order to subject the continuous band 6 to the action of a new portion
of the cutting edge 18a of each knife 18, for example when the previously used portion
is worn. Each knife 18 is also adapted to be mounted according to at least two different
positions, mutually rotated 180°, in order to offer a new, previously inactive portion
of the cutting edge 18a to the continuous band 6.
[0108] Preferably, the cutting unit 14 is freely movable in a direction transverse to the
longitudinal translation direction "F" of the continuous band 6. For such purpose,
the carriage 19 can be provided slidably mounted on a fixed support structure 23.
For example, the support structure 23 can have guide bars 24 that are transverse relative
to a longitudinal extension direction of the continuous band 6, slidably traversing
guide bushings 25 carried by the carriage 19.
[0109] The cutting unit 14 slidably engages the continuous band 6 at a centring guide 26.
[0110] More particularly the centring guide 26, preferably carried by the carriage 19, engages
the continuous band 6 at a passage opening 27 having width equal to the width of the
continuous band 6 itself. The continuous band 6 can thus maintain a centred positioning
with respect to the knives 18. Possible lateral movements of the continuous band 6
coming from the band feeding devices 5 are indeed easily followed by corresponding
lateral translations induced to the carriage 19. The engagement of the continuous
band 6 through the centring guide 26 in fact transmits transverse thrust forces to
the cutting unit 14, due to the same transverse movements of the continuous band 6.
[0111] Said guiding devices 28 are housed inside said generation region "Z" containing the
cutting unit 14. Devices 28 operate on the continuous strip-like elements 2 to impart
respective drift forces thereto, so as to guide them along mutually diverging trajectories
moving away from the respective knives 18.
[0112] More particularly, the guiding devices 28 comprise drift rollers 29, each of which
adapted to operate in contact relationship with one of the continuous strip-like elements
2, preferably by means of an operative surface 29a with convex profile.
[0113] Preferably, for each continuous strip-like element 2 produced by the cutting unit
14, at least two drift rollers 29 are provided which are mutually aligned along a
trajectory diverging from the longitudinal mid-line "L" of the continuous band 6.
[0114] Preferably, the drift rollers 29 are supported rotatably idle, each along a respective
rotation axis "X" slightly inclined to a direction perpendicular to the longitudinal
extension of a stretch of the continuous strip-like element 2 upstream of the drift
roller 29 itself. The passage of the continuous strip-like elements 2 against the
drift rollers 29 thus causes the generation of the desired drift thrusts, adapted
to impose diverging trajectories to the continuous strip-like elements 2 translating
away from the knives 18; such trajectories diverging with respect to each other and/or
with respect to the continuous band 6.
[0115] More particularly, the drift rollers 29 can be conveniently positioned in a manner
so as to impose, to each continuous strip-like element 2, at least one first deviation
from the lying plane "P" of the continuous band 6, subsequent to the cutting action
of the respective knives 18, and a second deviation opposite the first, i.e. directed
laterally relative to the longitudinal extension direction of the continuous band
6. The first and the second deviations can also be carried out simultaneously, as
components of a single oblique deviation.
[0116] Before reaching the drive unit 15, at least a part of the continuous strip-like elements
2 is also subjected to a third deviation towards the lying plane "P" of the continuous
band 6. The continuous strip-like elements 2 are conveniently disposed coplanar to
each other upon reaching the drive unit 15.
[0117] The size of the drift forces can be modulated by means of adjustment devices 30 associated
with the guiding devices 28. It is thus possible to confer a correct and stable trajectory
to the single continuous strip-like elements 2 generated by the cutting action.
[0118] The drift forces can also be modulated, if necessary, in response to possible transverse
movements carried out by the continuous band 6. These lateral movements are induced
to the continuous band 6 by various factors that are hard to predict or control, which
for example are displayed at the band feeding devices 5 or other zones upstream of
the cutting unit 14; such lateral movements are in fact followed by the lateral mobility
of the carriage 19, but cause relative movements between the knives 18 and the single
drift rollers 29, with consequent modification of the trajectories and drift thrusts
induced on the continuous strip-like elements 2. The modulability of the drift forces
allows compensating for these variations and restoring the dynamic equilibrium conditions
of the continuous strip-like elements 2 translating on the respective drift rollers
29.
[0119] For such purpose, each drift roller 29 can be conveniently supported by a rod 31
rotatably engaged through a base plate 32 carried by the support structure 23 of the
cutting unit 14. More particularly, each rod 31 is rotatable around a correction axis
"Y", perpendicular to the rotation axis "X" of the roller itself, upon actuation of
drive members 33 situated externally of the aforesaid region of generation "Z" of
continuous strip-like elements 2.
[0120] The drive members 33 comprise, for each drift roller 29, at least one first threaded
element 34, e.g. a ring nut, rotatably engaged with the support structure 23 of the
cutting unit 14, externally with respect to the aforesaid generation region "Z" containing
the cutting unit 14.
[0121] The first threaded element 34, axially fixed with respect to the support structure
23, operates on a transmission lever 35 associated with the respective rod 31. The
transmission lever 35 for example comprises a drive arm 36 operatively constrained,
e.g. by a ball joint 37, to a lever 38 engaged with one end of the respective rod
31 by means of a clamp 39, so as to project radially with respect to the aforesaid
correction axis "Y".
[0122] The first threaded element 34 operatively engages a second threaded element 40, represented
for example by a thread carried by the drive arm 36.
[0123] By driving the first threaded element 34 in rotation, it is thus possible to orient
the positioning of the respective drift roller 29 around the correction axis "Y",
so as to actuate a fine adjustment of the drift forces induced by the same drift roller
29 on the continuous strip-like element 2.
[0124] The modulation action of the drift forces can be manually executed, following a visual
control at fairly frequent intervals of the stability of the trajectories carried
out by the continuous strip-like elements 2 translating away from the knives 18. An
operator can in fact manually operate on the first threaded elements 34 for correcting
the trajectory imposed on one or more of the continuous strip-like elements 2, upon
detection of possible irregularities in the trajectories themselves. In order to facilitate
a timely operation by the operator, the use of signalling devices 41 may be provided
for emitting a notification signal, e.g. acoustic and/or visual, when the position
of a diverging stretch of at least one continuous strip-like element 2 exceeds a predetermined
tolerance threshold.
[0125] Such signalling devices 41 can for example comprise sensor members 42 e.g. of optical,
mechanical or other type, which detect the position of the diverging stretch of each
of the continuous strip-like elements 2, in the generation region "Z".
[0126] In an electronic control unit 43, preferably programmable, a theoretical reference
position is stored of the diverging stretch of each of the continuous strip-like elements
2. A comparator 44 associated with the electronic control unit 43 compares the position
detected by the sensor members 42 with the preset theoretical reference position.
[0127] When the difference between the position of the diverging stretch and the theoretical
reference position exceeds a predetermined tolerance threshold, the emission of the
notification signal is enabled by the signalling devices 41.
[0128] In a preferred embodiment, at least one actuator (not shown) acts on each first threaded
element 34 by automatically adjusting the orientation of the corresponding drift roller
39 around the aforesaid correction axis "Y" following an output signal of said electronic
control unit 43.
[0129] The cutting action of each knife 18 is exerted between two contiguous reinforcing
cords 3 of the continuous band 6, in a manner such that each continuous strip-like
element 2 has a predetermined number of reinforcing cords 3.
[0130] Nevertheless, it may occur that due to uncontrolled movements of the continuous band
6 with respect to the knives 18 during manufacturing at high speed, one or more of
the knives 18 cuts one of the adjacent reinforcing cords 3 and the system has a new
equilibrium condition in which not all of the continuous strip-like elements 2 are
formed in accordance with the correct width and/or with the predetermined number of
reinforcing cords 3.
[0131] In order to remedy the above situation, the cutting unit 14 can also be associated
with thrust devices 45 which, if necessary, are adapted to correcting the relative
positioning between the continuous band 6 and the knives 18 during translation of
the continuous strip-like elements 2, by imposing transverse movements to cutting
unit 14. More particularly, the thrust devices 45 are adapted to be driven from outside
the generation region "Z", in order to impose transverse movements to the knives 18
with respect to the drift rollers 29. Preferably, the thrust devices 45 comprise an
actuating arm 46 carried by a bar 47, preferably with circular section, that is axially
and rotatably movable through the support structure 23 of the carriage 19. A control
knob 48 carried by the bar 47 allows moving the actuating arm 46 between a rest condition
in which it is disengaged from the carriage 19 and an operative condition in which
it engages the carriage 19. For such purpose, the actuating arm 46 can be provided
for example with a fork-like end 49 in which a grip tab 50 carried by the centring
guide 26 is removably insertable.
[0132] In normal functioning conditions of the production line 1, the actuating arm 46 is
maintained in rest condition, disengaged from the carriage 19. When a correction operation
is required, an operator can intervene on the control knob 48 in order to bring the
actuating arm 46 in engagement relationship with the carriage 19, and transmit small
strikes or thrust actions to the carriage itself, so as to impose sudden transverse
movements to the knives 18.
[0133] These transverse movements cause a movement of the continuous band 6 with respect
to the knives 18, due to the reactions induced by the continuous strip-like elements
2 translating in engagement relationship on the drift rollers 29, so as to restore
the correct position of the latter with respect to the knives 18.
1. A process for controlled collection of continuous strip-like elements (2) for building
tyres, comprising:
feeding a continuous band (6) of elastomeric material comprising reinforcing cords
(3);
in a region of generation (Z) of continuous strip-like elements (2), cutting said
continuous band (6) generating continuous strip-like elements (2);
in said generation region (Z) of continuous strip-like elements (2), applying drift
forces to each of said continuous strip-like elements (2) to guide them along diverging
trajectories,
wherein said drift forces are generated by passage of the continuous strip-like elements
(2) against drift rollers (29);
collecting each continuous strip-like element (2), characterized by further comprising:
modulating said drift forces by drive members (33) placed externally of said generation
region (Z) of continuous strip-like elements (2);
laterally translating a carriage (19) carrying knives (18) for following transverse
movements of the continuous band (6); and
correcting the relative positioning between the continuous band (6) and the knives
(18) during translation of the continuous strip-like elements (2),
wherein corrections are carried out by imposing transverse movements to said knives
(18) relative to said drift rollers (29), against which the continuous strip-like
elements (2) pass.
2. A process as claimed in claim 1, wherein in said generation region (Z), at least one
first deviation from the lying plane ("P") of the continuous band (6), a second deviation
directed laterally relative to the longitudinal extension direction of the continuous
band (6), and at least one third deviation towards a lying plane (P) of the continuous
band (6) are imposed to the continuous strip-like elements (2), wherein said continuous
strip-like elements (2), following the third deviation, are brought into mutual-coplanarity
relationship.
3. A process as claimed in claim 1 or 2, wherein the action of modulating the drift forces
is carried out by rotating at least one of said drift rollers (29) around a correction
axis (Y) perpendicular to a rotation axis (X) thereof.
4. A process as claimed in one or more of the preceding claims, wherein the cutting action
is carried out simultaneously along the respectively opposite edges of the continuous
band (6) for generating pairs of continuous strip-like elements (2), wherein said
pairs of continuous strip-like elements (2) are generated in succession starting from
outer side edges of the continuous band (6).
5. A process as claimed in one or more of the preceding claims, wherein said transverse
movements are carried out by an actuating arm (46) that is disengaged from the cutting
unit (14) when correction has occurred.
6. A production line for controlled collection of continuous strip-like elements (2)
for building tyres, comprising:
band feeding devices (5) for feeding a continuous band (6) of elastomeric material
comprising reinforcing cords (3);
a cutting unit (14) slidably engaging said continuous band (6) and carrying knives
(18) operating through the continuous band (6) for generating continuous strip-like
elements (2) therefrom;
guiding devices (28) operating on said continuous strip-like elements (2) to impart
respective drift forces, guiding them along mutually diverging trajectories;
at least one collection unit for collecting each continuous strip-like element (2);
characterized by further comprising
adjustment devices (30) for modulating said drift forces on said continuous strip-like
elements (2),
wherein said adjustment devices (30) can be operated by drive members (33) disposed
externally of a generation region (Z) of said continuous strip-like elements (2),
thrust devices (45) for imposing transverse movements to the knives (18), wherein
the thrust devices (45) comprise an actuating arm (46) acting on a carriage (19) carrying
said knives.
7. A production line as claimed in claim 6, wherein the guiding devices (28) comprise
drift rollers (29) provided for operating in contact relationship with said continuous
strip-like elements (2), wherein each drift roller (29) is positionable around a correction
axis (Y) perpendicular to a rotation axis (X) thereof.
8. A production line as claimed in one or more of claims 6 to 7, wherein the knives (18)
are distributed so as to define a V-shaped configuration with vertex facing the collection
unit (16).
9. A production line as claimed in one or more of claims 6 to 8, wherein the knives (18)
are carried by a carriage (19) movable in a direction transverse to the feeding direction
of the continuous band (6).
10. A production line as claimed in one or more of claims 6 to 9, wherein the actuating
arm (46) is carried by a bar (47) that is axially movable for imposing a transverse
movement to the cutting unit (14).
1. Verfahren zur kontrollierten Aufnahme fortlaufender streifenförmiger Elemente (2)
zum Aufbauen von Reifen, umfassend:
Zuführen eines Endlosbandes (6) aus Elastomermaterial, das Verstärkungskorde (3) umfasst;
in einem Bereich der Erzeugung (Z) der fortlaufenden streifenförmigen Elemente (2)
Durchtrennen des Endlosbandes (6), sodass fortlaufende streifenförmige Elemente (2)
erzeugt werden,
in dem Erzeugungsbereich (Z) der fortlaufenden streifenförmigen Elemente (2) Ausüben
von Abdrängungskräften auf jedes der fortlaufenden streifenförmigen Elemente (2),
um sie auseinanderlaufende Bahnen entlangzuführen,
wobei die Abdrängungskräfte durch das Vorbeilaufen der fortlaufenden streifenförmigen
Elemente (2) an Abdrängungsrollen (29) erzeugt werden;
Aufnehmen jedes fortlaufenden streifenförmigen Elements (2), dadurch gekennzeichnet, dass es ferner umfasst:
Modulieren der Abdrängungskräfte durch Antriebselemente (33), die außerhalb des Erzeugungsbereiches
(Z) der fortlaufenden streifenförmigen Elemente (2) angeordnet sind;
seitliches Verschieben eines Messer (18) tragenden Schlittens (19), um Querbewegungen
des Endlosbandes (6) zu folgen; und
Korrigieren der relativen Positionierung des Endlosbandes (6) und der Messer (18)
während der Verschiebung der fortlaufenden streifenförmigen Elemente (2),
wobei Korrekturen dadurch erfolgen, dass den Messern (18) Querbewegungen in Bezug
auf die Abdrängungsrollen (29), an denen die fortlaufenden streifenförmigen Elemente
(2) vorbeilaufen, aufgezwungen werden.
2. Verfahren nach Anspruch 1,
wobei die fortlaufenden streifenförmigen Elemente (2) in dem Erzeugungsbereich (Z)
mindestens eine erste Ablenkung aus der Liegeebene ("P") des Endlosbandes (6), eine
zweite Ablenkung in seitlicher Richtung relativ zur Längserstreckungsrichtung des
Endlosbandes (6) und mindestens eine dritte Ablenkung hin zur Liegeebene (P) des Endlosbandes
(6) erfahren, wobei die fortlaufenden streifenförmigen Elemente (2) im Anschluss an
die dritte Ablenkung in eine Koplanaritätsbeziehung gebracht sind.
3. Verfahren nach Anspruch 1 oder 2, wobei der Vorgang des Modulierens der Abdrängungskräfte
durch Drehen mindestens einer der Abdrängungsrollen (29) um eine Korrekturachse (Y)
erfolgt, die senkrecht auf einer Drehachse (X) davon steht.
4. Verfahren nach einem oder mehreren der vorhergehenden Ansprüche, wobei der Vorgang
des Durchtrennens gleichzeitig entlang der jeweils gegenüberliegenden Kanten des Endlosbandes
(6) erfolgt, um Paare fortlaufender streifenförmiger Elemente (2) zu erzeugen, wobei
die Paare fortlaufender streifenförmiger Elemente (2) beginnend an den äußeren Seitenkanten
des Endlosbandes (6) nacheinander erzeugt werden.
5. Verfahren nach einem oder mehreren der vorhergehenden Ansprüche, wobei die Querbewegungen
durch einen Betätigungsarm (46) erfolgen, der vom Schneidwerk (14) getrennt wird,
wenn die Korrektur stattgefunden hat.
6. Produktionslinie zur kontrollierten Aufnahme fortlaufender streifenförmiger Elemente
(2) zum Aufbauen von Reifen, umfassend:
Bandzuführvorrichtungen (5) zum Zuführen eines Endlosbandes (6) aus Elastomermaterial,
das Verstärkungskorde (3) umfasst;
ein Schneidwerk (14), das verschiebbar in das Endlosband (6) eingreift und Messer
(18) trägt, die durch das Endlosband (6) hindurch wirksam sind, um daraus fortlaufende
streifenförmige Elemente (2) zu erzeugen;
Führungsvorrichtungen (28), die auf die fortlaufenden streifenförmigen Elemente (2)
einwirken, um jeweilige Abdrängungskräfte auf sie zu übertragen, die sie auseinanderlaufende
Bahnen entlangführen;
mindestens eine Aufnahmeeinheit zum Aufnehmen jedes fortlaufenden streifenförmigen
Elements (2);
dadurch gekennzeichnet, dass sie ferner umfasst:
Einstellvorrichtungen (30) zum Modulieren der Abdrängungskräfte auf die fortlaufenden
streifenförmigen Elemente (2),
wobei die Einstellvorrichtungen (30) durch Antriebselemente (33) betätigt werden können,
die außerhalb eines Erzeugungsbereiches (Z) der fortlaufenden streifenförmigen Elemente
(2) angeordnet sind,
Schubvorrichtungen (45), um den Messern (18) Querbewegungen aufzuzwingen, wobei die
Schubvorrichtungen (45) einen Betätigungsarm (46) umfassen, der auf einen die Messer
tragenden Schlitten (19) einwirkt.
7. Produktionslinie nach Anspruch 6, wobei die Führungsvorrichtungen (28) Abdrängungsrollen
(29) umfassen, die für einen Betrieb in Kontaktbeziehung mit den fortlaufenden streifenförmigen
Elementen (2) bereitgestellt sind, wobei jede Abdrängungsrolle (29) um eine Korrekturachse
(Y) positionierbar ist, die senkrecht auf einer Drehachse (X) davon steht.
8. Produktionslinie nach einem oder mehreren der Ansprüche 6 bis 7, wobei die Messer
(18) so verteilt sind, dass eine V-förmige Konfiguration mit einem der Aufnahmeeinheit
(16) zugewandten Scheitelpunkt definiert wird.
9. Produktionslinie nach einem oder mehreren der Ansprüche 6 bis 8, wobei die Messer
(18) von einem Schlitten (19) getragen werden, der in einer Richtung quer zur Transportrichtung
des Endlosbandes (6) beweglich ist.
10. Produktionslinie nach einem oder mehreren der Ansprüche 6 bis 9, wobei der Betätigungsarm
(46) von einer Stange (47) getragen wird, die axial beweglich ist, um dem Schneidwerk
(14) eine Querbewegung aufzuzwingen.
1. Procédé de collecte contrôlée d'éléments en forme de bande continue (2) pour la construction
de pneus, comprenant le fait :
d'acheminer une bande continue (6) de matériau élastomère comprenant des câblés de
renforcement (3) ;
dans une région de génération (Z) d'éléments en forme de bande continue (2), de couper
ladite bande continue (6) ce qui permet de générer des éléments en forme de bande
continue (2) ;
dans ladite région de génération (Z) d'éléments en forme de bande continue (2), d'appliquer
des forces de dérive à chacun desdits éléments en forme de bande continue (2) pour
les guider le long de trajectoires divergentes,
dans lequel lesdites forces de dérive sont générées par le passage des éléments en
forme de bande continue (2) contre des rouleaux de dérive (29) ;
de collecter chaque élément en forme de bande continue (2), caractérisé en ce qu'il comprend en outre le fait :
de moduler lesdites forces de dérive par des éléments d'entraînement (33) placés à
l'extérieur de ladite région de génération (4) d'éléments en forme de bande continue
(2) ;
de mettre en translation latérale un chariot (19) portant des couteaux (18) pour suivre
les mouvements transversaux de la bande continue (6) ; et
de corriger le positionnement relatif entre la bande continue (6) et les couteaux
(18) pendant la translation des éléments en forme de bande continue (2),
dans lequel des corrections sont effectuées en imposant des mouvements transversaux
auxdits couteaux (18) par rapport auxdits rouleaux de dérive (29), contre lesquels
passent les éléments en forme de bande continue (2) .
2. Procédé tel que revendiqué dans la revendication 1,
dans lequel, dans ladite région de génération (Z), au moins une première déviation
par rapport au plan de pose ("P") de la bande continue (6), une deuxième déviation
dirigée latéralement par rapport à la direction d'extension longitudinale de la bande
continue (6), et au moins une troisième déviation vers un plan de pose (P) de la bande
continue (6) sont imposées aux éléments en forme de bande continue (2), où lesdits
éléments en forme de bande continue (2), après la troisième déviation, sont amenés
en coplanarité mutuelle.
3. Procédé tel que revendiqué dans la revendication 1 ou 2, dans lequel l'action de modulation
des forces de dérive est effectuée en faisant tourner au moins l'un desdits rouleaux
de dérive (29) autour d'un axe de correction (Y) perpendiculaire à un axe de rotation
(X) de ceux-ci.
4. Procédé tel que revendiqué dans une ou plusieurs des revendications précédentes, dans
lequel l'action de coupe est effectuée simultanément le long des bords respectivement
opposés de la bande continue (6) pour générer des paires d'éléments en forme de bande
continue (2), où lesdites paires d'éléments en forme de bande continue (2) sont générées
successivement en partant des bords latéraux extérieurs de la bande continue (6).
5. Procédé tel que revendiqué dans une ou plusieurs des revendications précédentes, dans
lequel lesdits mouvements transversaux sont effectués par un bras d'actionnement (46)
qui est désengagé de l'unité de coupe (14) lorsque la correction s'est produite.
6. Chaîne de production pour la collecte contrôlée d'éléments en forme de bande continue
(2) pour la construction de pneus, comprenant :
des dispositifs d'acheminement de bande (5) pour acheminer une bande continue (6)
de matériau élastomère comprenant des câblés de renforcement (3) ;
une unité de coupe (14) s'engageant en coulissement avec ladite bande continue (6)
et portant des couteaux (18) fonctionnant à travers la bande continue (6) pour générer
des éléments en forme de bande continue (2) à partir de celle-ci ;
des dispositifs de guidage (28) fonctionnant sur lesdits éléments en forme de bande
continue (2) pour leur conférer des forces de dérive respectives, les guidant le long
de trajectoires mutuellement divergentes ;
au moins une unité de collecte pour collecter chaque élément en forme de bande continue
(2) ;
caractérisée en ce qu'elle comprend en outre
des dispositifs de réglage (30) pour moduler lesdites forces de dérive sur lesdits
éléments en forme de bande continue (2),
où lesdits dispositifs de réglage (30) peuvent être actionnés par des éléments d'entraînement
(33) disposés à l'extérieur d'une région de génération (Z) desdits éléments en forme
de bande continue (2),
des dispositifs de poussée (45) pour imposer des mouvements transversaux aux couteaux
(18), où les dispositifs de poussée (45) comprennent un bras d'actionnement (46) agissant
sur un chariot (19) portant lesdits couteaux.
7. Chaîne de production telle que revendiquée dans la revendication 6, dans laquelle
les dispositifs de guidage (28) comprennent des rouleaux de dérive (29) prévus pour
fonctionner en contact avec lesdits éléments en forme de bande continue (2), où chaque
rouleau de dérive (29) peut être positionné autour d'un axe de correction (Y) perpendiculaire
à un axe de rotation (X) de celui-ci.
8. Chaîne de production telle que revendiquée dans une ou plusieurs des revendications
6 et 7, dans laquelle les couteaux (18) sont répartis de manière à définir une configuration
en forme de V avec le sommet faisant face à l'unité de collecte (16).
9. Chaîne de production telle que revendiquée dans une ou plusieurs des revendications
6 à 8, dans laquelle les couteaux (18) sont portés par un chariot (19) mobile dans
une direction transversale à la direction d'acheminement de la bande continue (6).
10. Chaîne de production telle que revendiquée dans une ou plusieurs des revendications
6 à 9, dans laquelle le bras d'actionnement (46) est porté par une barre (47) qui
est axialement mobile pour imposer un mouvement transversal à l'unité de coupe (14).