[0001] The present invention relates to a machine for cutting soap bars into portions of
preset length with highly flexible operation.
[0002] As is known, in the manufacture of soap, soap is extruded in continuous bars, which
are cut into portions of preset length, which are then molded in order to obtain pieces
of soap with sizes and shapes suitable for sale.
[0003] In order to achieve high productivity, the soap bars are generally cut continuously,
i.e., without stopping the bar of soap during its advancement along the production
line.
[0004] Specifically-made machines are currently used to perform this operation and can be
grouped into mechanically-driven machines and electronically-driven machines.
[0005] Mechanically-driven machines generally comprise a supporting structure, which forms
a support and advancement surface for the soap bar to be cut, and a plurality of blades,
which are mounted on a chain and are mutually spaced with a pitch which corresponds
to the length of the portions of bar to be cut. The chain faces, with one of its portions,
the soap bar arranged on the support and advancement surface and moves gradually closer,
with said portion, to the support and advancement surface so as to gradually make
the blades interfere with the soap bar in order to cut it. The actuation of the chain
is synchronized with the advancement of the soap bar so as to obtain, for the blades
that interfere with the soap bar, an advancement speed, in the direction of advancement
of the soap bar, which is equal to the advancement speed of the soap bar.
[0006] These kinds of machines allow to vary the length of the portions of the bar to be
cut, i.e., the cutting length, since the blades are connected to the chain by means
of kinematic mechanisms on which it is possible to act manually in order to vary the
spacing between the blades.
[0007] A first problem which can be observed in these machines is structural complexity,
which arises mainly from the presence of the kinematic mechanisms required to change
the cutting length, which affects significantly the production costs of these machines.
[0008] Another problem is constituted by low flexibility, since although it is possible
to vary the cutting length, said length in any case is constrained within a rather
narrow range, which is not always capable of meeting production requirements.
[0009] Moreover, the operation for varying the cutting length is time-consuming and laborious,
requires halting the production line, with consequent production losses, and requires
the intervention of specialized personnel.
[0010] Another problem of these machines is poor cutting precision.
[0011] Electronically-driven machines also comprise a supporting structure which forms a
support and advancement surface for the soap bar to be cut. Such machines are provided
with a blade which faces said support and advancement surface and can move on command,
with a reciprocating motion, along a direction which is substantially perpendicular
to the support and advancement surface. The blade, in some machines, is mounted on
an arm which can oscillate about an axis which is parallel to the support and advancement
surface and is oriented transversely to the advancement direction of the soap bar
along said surface. The oscillation of the arm allows the blade to follow the soap
bar during cutting and to move backward with respect to the bar in order to reposition
itself before performing a subsequent cut. In other machines, the blade is mounted
on an articulated quadrilateral or other kinematic mechanism which allows it likewise
to follow the soap bar during cutting and to move backward between one cut and the
next. Generally, the motion of the blade along the direction of advancement of the
soap bar is achieved by means of the direct traction performed by the soap bar when
the blade begins to interfere with the soap bar, while the motion of the blade in
the opposite direction, after the blade has ended its cutting action and has been
disengaged from the soap bar, is obtained by means of elastic elements which are loaded
by the advancement of the blade together with the soap bar.
[0012] Electronically-driven machines are generally provided with means for sensing the
advancement speed of the soap bar, and the actuation of the blade at right angles
to the support and advancement surface is adjusted as a function of the preset cutting
length.
[0013] In practice, the operating cycle of such machines comprises a cutting step, during
which the blade cuts the soap bar, advancing together with the soap bar, and a repositioning
step, in which the blade is disengaged from the soap bar and moves in the opposite
direction with respect to the soap bar in order to be returned to the initial position
to perform a new cut. To meet the requirement of being able to produce different cutting
lengths and of working with relatively high soap bar advancement speeds, the second
step must be very short. This entails high accelerations and decelerations in the
reciprocating motion of the blade at right angles to the support and advancement surface,
which cause excessive stresses in the machine.
[0014] The aim of the present invention is to solve the problems described above by providing
a machine for cutting soap bars into portions of preset length which is highly flexible
in operation and is capable of meeting the most disparate requirements as regards
the cutting length without generating excessive stresses of the elements that compose
it.
[0015] Within this aim, an object of the invention is to provide a machine which can be
fitted without problems on modem production lines with high extrusion rates.
[0016] Another object of the invention is to provide a machine which allows to vary the
cutting length in an extremely short time and optionally even during its operation.
[0017] Another object of the invention is to provide a structurally simple machine which
can be produced at competitive costs and requires limited maintenance interventions.
[0018] Another object of the invention is to provide a machine which has high cutting precision.
[0019] This aim and these and other objects, which will become better apparent hereinafter,
are achieved by a machine for cutting soap bars into portions of preset length, which
comprises:
- a supporting structure, which forms a surface for the support and advancement of the
soap bar along a longitudinal advancement direction;
- means for detecting the advancement speed of said bar along said advancement direction;
- cutting means, which comprise at least one blade which can move toward and away with
respect to said support and advancement surface in order to interfere with the soap
bar, a control and actuation element of the electronic type which is functionally
connected to said means for sensing the advancement speed of the soap bar along said
advancement direction and to said cutting means in order to actuate said cutting means
as a function of the advancement speed of the soap bar and of a preset length for
the portions of bar to be cut;
characterized in that said cutting means comprise:
- at least one arm which can rotate about a rotation axis which is substantially parallel
to said support and advancement surface and is oriented transversely to said advancement
direction;
- a motor for actuating said at least one arm with a rotary motion about said rotation
axis and with a variable rotation rate, actuated by said actuation and control element;
and
- at least one blade which is mounted on said at least one arm in a region which is
spaced from said rotation axis;
said blade being movable, as a consequence of the rotation of said arm about said
rotation axis, along a path which is substantially tangent to said support and advancement
surface; means for orienting the blade being provided in order to keep said blade
on a plane which is substantially perpendicular to said support and advancement surface
and to said advancement direction at least within an interval of distance of said
blade from said support surface which is equal to the thickness of said soap bar meant
to be crossed by said blade and synchronization means being provided in order to keep
the component of the speed of said blade along said advancement direction substantially
equal to the advancement speed of the bar at least within said distance interval.
[0020] Further characteristics and advantages of the invention will become better apparent
from the description of a preferred but not exclusive embodiment of the machine according
to the invention, illustrated by way of non-limiting example in the accompanying drawings,
wherein:
Figure 1 is a front elevation view of the machine according to the invention at the
beginning of the cutting step;
Figure 2 is a front elevation view of the machine according to the invention during
the cutting step;
Figure 3 is a front elevation view of the machine according to the invention at the
end of the cutting step;
Figure 4 is an enlarged-scale view of a detail of Figure 2, with the soap bar removed
for the sake of greater clarity;
Figure 5 is a sectional view of Figure 4, taken along the line V-V;
Figure 6 is a top plan view of the machine according to the invention.
[0021] With reference to the figures, the machine according to the invention, generally
designated by the reference numeral 1, comprises a supporting structure 2, which forms
a surface 3 for the support and advancement of a soap bar 4 to be cut, which advances
along a longitudinal direction indicated by the arrow 5.
[0022] The machine is provided with means 6 for sensing the advancement speed of the soap
bar 4 along the advancement direction 5 and with cutting means 7 which can be actuated
so as to interfere cyclically with the soap bar 4 during its advancement along the
direction 5 so as to cut it into portions of preset length.
[0023] The support and advancement surface 3 is preferably arranged horizontally, and along
such surface there are guiding means for the soap bar 4. The guiding means comprise
for example two pairs of rollers 8a, 8b, 9a, 9b, the axes of which are oriented substantially
at right angles to the support and advancement surface 3. These rollers 8a, 8b, 9a,
9b are supported so that they can rotate about their respective axes by the supporting
structure 2 and are arranged upstream of the cutting means 7 along the advancement
direction 5.
[0024] Moreover, the guiding means comprise two side walls 10a, 10b, which are arranged
along planes which are substantially perpendicular to the support and advancement
surface 3 downstream of the cutting means 7 along the advancement direction 5. The
rollers 8a, 8b, 9a, 9b, as well as the walls 10a, 10b, are designed to limit the possibility
of movement of the soap bar 4 on the support and advancement surface 3 at right angles
to the advancement direction 5.
[0025] The advancement of the soap bar 4 on the support and advancement surface 3 can be
achieved by simple sliding of the soap bar 4 as a consequence of the thrust produced
by the extrusion process which occurs upstream of the machine according to the invention
or, as an alternative or in combination, can be obtained by providing the support
and advancement surface 3 as a belt 40 which is supported by a pair of pulleys 41
a, 41b, which are arranged so that their axes lie at right angles to the advancement
direction 5.
[0026] The cutting means comprise at least one blade 11, 12, which can move toward and away
from the support and advancement surface 3 in order to interfere with the soap bar
4. The cutting means 7 are actuated by an actuation and control element 13, of the
programmable electronic type, which is functionally connected to the means 6 for sensing
the advancement speed of the soap bar 4 along the advancement direction 5 and to the
cutting means 7 so as to actuate the cutting means 7 as a function of the advancement
speed of the soap bar 4 along the advancement direction 5 and of a preset length,
or cutting length, for the portions of bar to be cut.
[0027] According to the invention, the cutting means 7 comprise at least one arm 14, which
can rotate about a rotation axis 15 which is substantially parallel to the support
and advancement surface 3 and is oriented transversely to the advancement direction
5. The arm 14 is connected to an actuation motor 16 of the variable-speed type, which
can be actuated in order to produce the rotation of the arm 14 about the rotation
axis 15.
[0028] At least one blade 11, 12 is mounted on the arm 14 in a region which is spaced from
the rotation axis 15.
[0029] As a consequence of the rotation of the arm 14 about the rotation axis 15, the blade
11, 12 follows a path which is substantially tangent, in one point, to the support
and advancement surface 3, and means for orienting the blade 11, 12 are provided in
order to keep said blade 11, 12 on a plane which is substantially perpendicular to
the support and advancement surface 3 and to the advancement direction 5 at least
within an interval of distance of the blade 11, 12 from the support and advancement
surface 3 which is equal to the thickness of the soap bar 4 to be crossed by the blade
11, 12. The machine further comprises synchronization means in order to keep the component
of the speed of the blade 11, 12 along the advancement direction 5 substantially equal
to the advancement speed of the soap bar 4 at least within said distance interval,
i.e., when the blade 11, 12 is engaged with the soap bar 4 during cutting.
[0030] Preferably, the orientation means of the blade 11, 12 are of the kinematic type and
link the blade 11, 12 to the rotation of the arm 14 about the rotation axis 15.
[0031] More particularly, the arm 14 is pivoted, at an intermediate region, to the supporting
structure 2 about the rotation axis 15. The arm 14 supports, in two mutually opposite
regions which are equidistant with respect to the rotation axis 15, two blades 11,
12, which can engage alternately the soap bar 4 as a consequence of the rotation of
the arm 14 about the rotation axis 15.
[0032] With particular reference to Figure 5, the arm 14 is fixed, so as to rotate rigidly
about the rotation axis 15, to a hollow shaft 18, the axis of which coincides with
the rotation axis 15 and is supported by the supporting structure 2 so that it can
rotate about said axis by means of a pair of bearings 19a and 19b. A pulley 20 is
fixed to the hollow shaft 18 and connects said hollow shaft 18 to the output shaft
of the variable-speed motor 16.
[0033] With particular reference to Figures 5 and 6, the orientation means of the blade,
or rather of the two blades 11 and 12, comprise a gear system which is composed of
a central gear 21, whose axis coincides with the rotation axis 15, and of two planetary
gears 22 and 23, which mesh with two diametrically mutually opposite regions of the
central gear 21 and are arranged so that their axes are parallel to the rotation axis
15. An end gear 24 and 25 meshes with each of these planetary gears 22 and 23, and
its axis likewise is oriented parallel to the rotation axis 15.
[0034] The central gear 21 is fixed to a shaft 26 which passes coaxially through the hollow
shaft 18 and is rigidly fixed to the supporting structure 2. A pair of bearings 27a,
27b is arranged between the hollow shaft 18 and the shaft 26.
[0035] The planetary gears 22 and 23 are supported so that they can rotate about their respective
axes, by means of pairs of bearings 28a, 28b, 29a, 29b, by the arm 14. Likewise, the
end gears 24 and 25 also are supported so that they can rotate about their respective
axes by means of pairs of bearings 30a, 30b, 31a, 31b by the arm 14.
[0036] Moreover, the rotation axis 15 and the axes of the planetary gears 22 and 23 and
of the end gears 24 and 25 are arranged on a same plane.
[0037] The end gears 24 and 25 have the same number of teeth as the central gear 21.
[0038] The blades 11 and 12 are rigidly fixed to the end gears 24 and 25. In greater detail,
the blades 11 and 12 are mounted on respective bows 33 and 34, which are fixed to
blocks 35 and 36 which in turn are fixed to the end gears 24 and 25.
[0039] The blades 11 and 12 are arranged on planes which are perpendicular to the support
and advancement surface 3 and the kinematic connection provided by means of the central
gear 21, the planetary gears 22 and 23 and the end gears 24 and 25 maintains this
orientation of the blades 11 and 12 during the rotation of the arm 14 about the rotation
axis 15.
[0040] The synchronization means comprise a program which is preset in the actuation and
control element 13 and is adapted to obtain, for the arm 14, an actuation with a rotary
motion about the rotation axis 15 with a speed which can vary as a function of the
advancement speed of the soap bar 4 along the advancement direction 5, so as to maintain
the component of the speed of the blade 11 or 12 in engagement with the soap bar 4,
along the advancement direction 5, substantially equal to the advancement speed of
the soap bar 4, while the blade 11 or 12 is engaged with the soap bar 4, and in a
manner adapted to obtain an advancement of the soap bar 4 along the support and advancement
surface 3, between the disengagement of one blade 11 or 12 from the soap bar 4 after
cutting it and the subsequent engagement of the other blade 12 or 11 with the soap
bar 4, which is equal to the preset length, or cutting length, for the portion of
bar to be cut.
[0041] The means 6 for sensing the advancement speed of the bar of soap 4 along the support
and advancement surface 3 comprise a contact roller 37, which is arranged so that
its axis lies parallel to the support and advancement surface 3 and at right angles
to the advancement direction 5.
[0042] The contact roller 37 is spaced from the support and advancement surface 3 so as
to make contact with the face of the soap bar 4 that lies opposite the face that rests
on the support and advancement surface 3.
[0043] The contact roller 37 is connected to an encoder which detects the rotation rate
of the contact roller 37 and therefore the advancement speed of the soap bar 4 along
the advancement direction 5 and transmits it to the control and actuation element
13.
[0044] Operation of the machine according to the invention is as follows.
[0045] The intended length for the portions to be cut from the bar of soap 4, i.e., the
chosen cutting length, is set in the control and actuation element 13.
[0046] The control and actuation element 13, by knowing the advancement speed of the soap
bar 4 along the advancement direction 5 transmitted by the encoder connected to the
contact roller 37, actuates, according to the program that is preset in the control
and actuation element 13, the actuation motor 16, which in turn produces the rotation
of the arm 14 about the rotation axis 15.
[0047] The rotation of the arm 14 about the rotation axis 15 cyclically causes the blades
11 and 12 to interfere with the soap bar 4 during its advancement along the advancement
direction 5, cutting the soap bar 4 into portions whose length is preset in the control
and actuation element 13.
[0048] More particularly, the control and actuation element 13 turns, by means of the actuation
motor 16, the arm 14 about the rotation axis 15 with a rotation rate which is variable
during a cutting cycle, so as to adapt the action of the blades 11 and 12 on the soap
bar 4 to the advancement speed of the soap bar 4 along the direction 5 and to the
preset cutting length.
[0049] More particularly, the rotation rate of the arm 14, while one blade 11 or 12 is cutting
the soap bar 4, is such as to obtain a movement of said blade along the advancement
direction 5 at a speed which is equal to the advancement speed of the soap bar 4 along
the same direction. After such blade has been disengaged from the soap bar 4 and before
the other blade engages the soap bar 4, the rotation speed of the arm 14 about the
rotation axis 15 is changed so that the next blade engages the soap bar at a distance
from the previous cut which is equal to the preset cutting length as a function of
the advancement speed of the soap bar 4 along the direction 5.
[0050] It should be noted that during the operation of the machine the cutting length can
be changed simply by setting a new cutting length in the control and actuation element
13.
[0051] In practice it has been found that the machine according to the invention fully achieves
the intended aim, since it provides a high operating flexibility which is capable
of meeting the most disparate requirements as regards the cutting length and, thanks
to the particular actuation of the blade or blades, does not cause excessive stresses
for the elements that compose it.
[0052] Another advantage of the machine according to the invention is that it allows to
vary the cutting length even during the operation of the machine.
[0053] The machine thus conceived is susceptible of numerous modifications and variations,
all of which are within the scope of the appended claims; all the details may further
be replaced with other technically equivalent elements.
[0054] In practice, the materials used, as well as the dimensions, may be any according
to requirements and to the state of the art.
[0056] Where technical features mentioned in any claim are followed by reference signs,
those reference signs have been included for the sole purpose of increasing the intelligibility
of the claims and accordingly such reference signs do not have any limiting effect
on the interpretation of each element identified by way of example by such reference
signs.
1. A machine for cutting soap bars into portions of preset length, comprising:
- a supporting structure, which forms a surface for the support and advancement of
the soap bar along a longitudinal advancement direction;
- means for detecting the advancement speed of said bar along said advancement direction;
- cutting means, which comprise at least one blade which can move toward and away
with respect to said support and advancement surface in order to interfere with the
soap bar, a control and actuation element of the electronic type which is functionally
connected to said means for sensing the advancement speed of the soap bar along said
advancement direction and to said cutting means in order to actuate said cutting means
as a function of the advancement speed of the soap bar and of a preset length for
the portions of bar to be cut;
characterized in that said cutting means comprise:
- at least one arm which can rotate about a rotation axis which is substantially parallel
to said support and advancement surface and is oriented transversely to said advancement
direction;
- a motor for actuating said at least one arm with a rotary motion about said rotation
axis and with a variable rotation rate, actuated by said actuation and control element;
and
- at least one blade which is mounted on said at least one arm in a region which is
spaced from said rotation axis;
said blade being movable, as a consequence of the rotation of said arm about said
rotation axis, along a path which is substantially tangent to said support and advancement
surface; means for orienting the blade being provided in order to keep said blade
on a plane which is substantially perpendicular to said support and advancement surface
and to said advancement direction at least within an interval of distance of said
blade from said support surface which is equal to the thickness of said soap bar intended
to be crossed by said blade and synchronization means being provided in order to keep
the component of the speed of said blade along said advancement direction substantially
equal to the advancement speed of the bar at least within said distance interval.
2. The machine according to claim 1, characterized in that said means for orienting the blade are of the kinematic type and link said blade
to the rotation of said arm about said rotation axis.
3. The machine according to claims 1 and 2, characterized in that said arm is pivoted, at an intermediate region thereof, to said supporting structure
about said rotation axis, and supports, in mutually opposite regions which are equidistant
from said rotation axis, two blades which can engage alternately the soap bar as a
consequence of the rotation of said arm about said rotation axis.
4. The machine according to one or more of the preceding claims, characterized in that said blade orientation means comprise a gear system composed of a central gear, whose
axis coincides with said rotation axis and which is fixed to said supporting structure,
two planetary gears which mesh with two diametrically mutually opposite regions of
said central gear and are supported by said arm so that they can rotate about the
respective axes, which are parallel to said rotation axis; an end gear meshing with
each of said planetary gears and being supported so that it can rotate about its own
axis by said arm and rigidly supporting one of said two blades.
5. The machine according to one or more of the preceding claims, characterized in that said rotation axis, the axis of said planetary gears and the axes of said end gears
are mutually coplanar.
6. The machine according to one or more of the preceding claims, characterized in that said synchronization means comprise a program which is preset in said actuation and
control element and is adapted to obtain, for said arm, an actuation with a rotary
motion about said rotation axis with a speed which can vary as a function of the advancement
speed of said bar along said advancement direction in order to keep the component
of the speed of said blade along said advancement direction substantially equal to
the advancement speed of the bar within said distance interval and in order to obtain
an advancement of the soap bar along said support and advancement surface, between
the disengagement of one blade from the soap bar after cutting it and the subsequent
engagement of the other blade with the soap bar, which is equal to the preset length
for the bar portion to be cut.
7. The machine according to one or more of the preceding claims, characterized in that said means for sensing the advancement speed of the soap bar along said support and
advancement surface comprise an encoder which is connected to a contact roller which
makes contact with the soap bar, said contact roller being arranged so that its axis
lies transversely to said advancement direction.