Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H20/00—Advancing webs
  • B65H20/24—Advancing webs by looping or like devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2301/00—Handling processes for sheets or webs
  • B65H2301/40—Type of handling process
  • B65H2301/44—Moving, forwarding, guiding material
  • B65H2301/449—Features of movement or transforming movement of handled material
  • B65H2301/4491—Features of movement or transforming movement of handled material transforming movement from continuous to intermittent or vice versa

Definitions

• the invention relates to a method and an apparatus for working band material, in particular for cutting side portions of a band made of flexible material.
• the invention can be usefully used for cutting band material, intended for forming elements for electric energy accumulating devices such as, for example, lithium ion batteries, capacitors, supercapacitors and similar devices, in such a manner as to obtain a profile shaped with a series of protrusions and recesses according to a desired geometry.
• electric energy accumulating devices such as, for example, lithium ion batteries, capacitors, supercapacitors and similar devices
• the band to be cut is kept stationary with respect to the cutting means, at least during the active cutting step.
• the working method in question is of the type according to the preamble of the first claim, in which it is not necessary for the operating means that act on the band in the work station to be provided with reciprocating motion in a longitudinal direction to the supplying line of the band being worked, as, in the portion of the band path where there is the work station, the band is guided by a kinematic system in such a manner as to perform a series of operating cycles, each of which comprises a stationary step, in which the band is stationary and the tools of the work station can work effectively, and a recovery step, in which the band advances quickly through the work station to ensure continuity of motion over the rest of the path.
• One object of the invention is to overcome the aforesaid limits and drawbacks of the prior art, devising a method for working a band in a work station that works intermittently, in which the band is conveyed forwards regularly and continuously, but having at least one band portion that, at each work cycle, stops temporarily in the work station.
• One advantage is to permit a long stationary time of the band in the work station.
• One advantage is to permit very regular advancement of the band, minimising perturbations due to traversing of the zones in which, in order to permit dwelling of part of the band, a cycle of accumulating and recovering the band occurs.
• One advantage is to provide a very versatile working method that is able to vary the operating parameters simply and rapidly, in particular without the need to make structural modifications to the working system.
• One advantage is to ensure the desired working precision, having, at the same time, high productivity.
• One advantage is to perform reliable and precise lateral cutting of band material to make components intended for forming electric energy accumulating devices.
• One object of the invention is to provide an apparatus for working a band that is dragged forwards regularly and continuously and has a portion that, at each work cycle, stops temporarily in a work station that operates intermittently.
• a band which is supplied along a path that passes through a work station that operates intermittently, is coupled with rotating tensioning means that perform a series of work cycles in which each cycle comprises a band stop step in which there is an increase of the band path upstream of the work station and a decrease of the path downstream, in order to maintain the band stationary in the work station, and a band recovery step, in which there is a decrease of the path upstream and an increase of the path downstream, to pass the band portion accumulated during the stop step quickly through the work station in order to ensure continuity in the motion of the band in the rest of the path.
• the rotating tensioning means is rotated at a variable rotating speed with a periodical undulating course.
• the band can be unwound continuously from a reel, for example at constant speed.
• the rotating tensioning means can form two loops of variable size in the path of the band, one upstream and the other downstream of the work station, in which the rotation of the tensioning means produces a variation in size of the loops.
• a dragging device advances a band continuously, for example at constant speed, along a preset path that passes through a cutting station, whilst two eccentric rollers coupled with the band, one upstream and the other downstream of the station, induce a band portion to perform cyclically a stop in the cutting station in which, during the stop, a lateral band portion is cut to form a shaped contour that is suitable for making, for example, elements of an electric energy accumulating device, in particular a lithium battery, a capacitor, a supercapacitor, etc.
• the band is wound on the two eccentric rollers that are rotated at variable rotating speed with a periodical undulating course.
• Figure 1 is a vertical raised side view of an example of the apparatus in question.
• Figure 2 shows an enlarged detail of the apparatus in figure 1.
• Figure 3 is a diagram of the rotation speeds of the eccentric rollers depending on the rotation angle in two configurations that differ from one another by the advancement step of the band at each cycle.
• Figure 4 is a diagram of the rotation speeds of the eccentric rollers depending on the rotation angle in two configurations that differ from one another by the band dwell period in the work station.
• Figure 5 is a diagram of the advancement speed of the band in the work station as a function of the rotation angle of the eccentric rollers in three configurations that differ from one another by the band dwell period in the work station.
• an apparatus has been indicated overall for working band material 2, in particular for cutting the band 2.
• the apparatus 1 can serve for cutting a side portion of the band 2, in such a manner as to make a shaped edge (with protrusion/s alternating with recess/es) of an element for an electric energy accumulating device, for example a lithium battery, a capacitor, a supercapacitor, etc.
• the apparatus 1 comprises supplying means for continuously supplying (at constant speed) the band 2 along a supply path.
• the supplying means may comprise, as in the specific case, a dragging device having two grippers 3 and 4 that are able to grasp the band 2 and arranged one after the other along the supplying path of the band 2.
• Each gripper 3 and 4 is provided with an alternating movement with an outward stroke and a return stroke.
• the dragging device is controlled according to a preset work cycle, such that whilst a gripper (3 or 4) performs the outward stroke in the closing position by grasping the band to drag the band forwards, the other gripper (4 or 3) performs the return stroke in the opening position, in which it leaves the band free, to then restart in the subsequent cycle with the outward stroke in which it retakes the band, which will be freed by the other gripper, which at the same time performs the return stroke.
• the coordinated work of the two movable grippers forwards and backwards enables the band 2 to regularly and continuously advance (at constant speed).
• the apparatus 1 comprises a work station 5 (in particular, a cutting station for cutting the side edge of the band) provided with working means, for example two cutting half moulds 6 and 7 that are movable alternatively between an open position and a closed position to cut intermittently at least one side portion of the band 2.
• the apparatus 1 comprises first tensioning means arranged for continuously varying the length of the path of the band 2 in a first portion upstream of the work station 5. The first tensioning means determines an accumulating step of the band 2 in which the band will have nil speed in the work station 5.
• the apparatus 1 further comprises second tensioning means arranged for continuously varying the length of the path of the band 2 in a second portion downstream of the work station 5 to compensate for the variation in the length of the band 2 in the first portion upstream of the station. This compensation will enable the overall length of the path of the band 2 to be maintained constant in a portion of path comprised between the first tensioning means and the second tensioning means.
• the first and second tensioning means substantially enables a path portion to be obtained in which the band 2 has intermittent motion (with a cycle having a dwell step at a substantially nil speed in which the band accumulates and a fast advancement step in which the accumulated band is recovered), whereas in the rest of the path the band 2 has continuous motion (for example at constant speed).
• the work station 5 is in the part of the path with intermittent motion of the band 2, whereas the dragging device (grippers 3 and 4) is in the rest of the path with continuous motion of the band 2.
• the dragging device is arranged downstream of the second tensioning means.
• the first tensioning means is configured so as to form a loop of the band 2 of variable size.
• the first tensioning means comprises a first cylindrical body, for example a first roller 8, carried, in an eccentric position, from a first rotating support (first crank disc 9) rotated around a first rotation axis that is transverse to the advancement direction F of the band 2.
• the second tensioning means will comprise a second cylindrical body, for example a second roller 10, carried, in an eccentric position, from a second rotating support (second crank disc 1 1) rotated (in the same direction as the first support) around a second rotation axis that is transverse to the advancing direction F of the band 2 (parallel to the first rotation axis).
• the band 2 will be coupled with the two eccentric rollers 8 and 10.
• Each eccentric roller 8 and 10 is carried freely rotatable on the respective support.
• the path of the band may comprise, as in this case, at least a first reel 12, at the start of the path, from which the band will unwind.
• various tensioning rollers 13 (with a stationary rotation axis) may be arranged that are coupled with the band 2.
• the band 2 may, for example, be rewound on at least a second reel 14.
• the apparatus 1 comprises means for varying cyclically the rotation speed of the first tensioning means of the band and of the second tensioning means of the band so as to have, at each work cycle, at least one speed increase and at least one speed decrease step.
• Such means for varying may comprise, as in the specific case, a programmable electronic control unit and programme instructions that are implementable on the control unit to control the driving means that rotate the first and the second tensioning means of the band.
• each crank disc will be rotated by a respective motor (not shown) controlled by the control unit according to a preset computer programme.
• the apparatus 1 will actuate a band material working method with the following steps.
• movable grippers 3 and 4 will advance the band 2 with continuous motion (for example at constant speed), at least in the continuous motion part of the path not comprised between the two eccentric rollers 8 and 10.
• the band will be unwound from the reel 12 (and possibly rewound on the reel 14) with a continuous and regular motion.
• the work station (cutting station) will operate intermittently on the band 2, with a series of work cycles, in the intermittent motion part of the path comprised between the two eccentric rollers 8 and 10.
• the first tensioning means of the band in particular the first crank disc 9 that eccentrically carries the first roller 8 will be rotated to vary cyclically the length of the first path portion upstream of the work station 5, so as to stop the band 2 temporarily in the work station at each work cycle.
• the second band tensioning means in particular the second crank disc 1 1 that eccentrically carries the second roller 10, will be rotated to vary cyclically the length of the second path portion downstream of the work station, in such a manner as to compensate for the variation in length of the first path portion and thus permit continuous motion of the band in the path portion downstream of the second roller 10.
• the rotation speed of the first tensioning means and/or of the second tensioners will be controlled in such a manner as to give rise to a cyclical pattern of the speeds that has, at each work cycle, at least one speed increase step and at least one speed decrease step.
• the rotation speed of the first tensioning means and/or of the second tensioners can have a periodic undulating pattern. In this manner, it is possible to obtain a relatively long band stationary period, with a regular band motion that is almost devoid of perturbation, ensuring great precision in working (lateral cutting) of the band.
• the rotation speed of the first tensioning means is varied, in particular, to determine, at each revolution (of the first crank disc 9), a stationary period, in which the band 2 remains stationary in the work station 5, and a moving period, in which the band advances in the work station.
• the stationary period can be obtained at an angular movement of the first tensioning means that is greater than or the same as at least 30 degrees of rotation.
• the maximum absolute value of the accelerations of the first tensioning means in the moving period may be the same as or less than the maximum absolute value of the accelerations of the first tensioning means in the stationary period. By doing so, the regularity of the movement of the band can be improved, decreasing the risk of perturbation of the motion.
• the rotation speed of the first band tensioning means may be varied to determine, at each revolution, a single maximum speed and a single minimum speed.
• the rotation speed of the second tensioning means may be varied to determine, at each revolution, a single maximum speed and a single minimum speed.
• the absolute values of the accelerations of the first band tensioning means may be, instant by instant, substantially the same as the absolute values of the accelerations of the second band tensioning means.
• the diagram in figure 3 shows the rotation speed of first crank disc 9 that carries the first eccentric roller 8 (upstream of the work station) and of the second crank disc 1 1 that carries the second eccentric roller 10 (downstream of the work station), which are measured as a percentage ratio of a reference rotation speed that is assumed to be the same as 100%.
• the values of the rotation speeds are evaluated according to the angular position adopted by the rollers 8 and 10 around the respective rotation axis from a reference position that is assumed to be equal to 0 (zero) degrees.
• two different configurations are shown relating to two different advancement steps of the band in the work station at each work cycle.
• Varying the advancement step enables the apparatus to be adjusted according to the band length that has to be worked (cut) at each cycle in the work station. In particular, this enables products to be made (elements for electric energy accumulating devices) of different sizes.
• the two different configurations relate to two different sizes of product with lengths, respectively of 131 mm and of 134 mm.
• the dwell period in which the band has nil speed in the work station occurs in the angular movement portion of the eccentric rollers comprised between 0 and 120 degrees.
• the band advances in the work station at an average recovery speed that will be greater than the average speed (which in particular will be constant) with which the dragging device advances the band.
• the curves are shown of the values assumed by the rotation speeds of the two eccentric rollers 8 and 10 in two different configurations in which the dwell period is varied during which the band has a nil speed in the work station.
• the dwell period occurs in the angular movement portion of the eccentric rollers 8 and 10 comprised between 0 and 120 degrees
• the band dwell period occurs in the portion comprised between 0 and 90 degrees.
• FIG 5 three curves are shown relating to the advancement speeds of the band in the work station, at each work cycle, according to the angle of rotation of the eccentric rollers 8 and 10 (in the case of the 131 mm size), in three different configurations in which the band dwell period occurs in the rotation portions comprised respectively between 0 and 40 degrees, between 0 and 90 degrees and between 0 and 120 degrees (these are respectively the curves "Sosta40°”, “Sosta90°” and “Sostal20°”).
• the speed pattern of the speed of the (continuously) moving band in the path outside the portion comprised between the eccentric rollers 8 and 10 (“VelocProdotto") is also shown, a pattern that, in the specific case, is shown by a horizontal straight line that indicates a constant speed.
• the values of the advancement speeds are expressed as a percentage of the (constant) value of the band speed in the path outside the tensioning means.
• the rotating tensioning means is arranged for forming two loops of variable size in the path of the band, one loop upstream and one loop downstream of the work station.
• Rotating the tensioning means produces a variation in the size of the loops in a coordinated manner so that the length of the path portion comprised between the tensioning means remains substantially constant, so as to avoid disturbances in the motion of the band outside the rotating tensioning means.
• some of the variables of the system that is disclosed here can be modified without changing the mechanical parts of the system, but through relatively simpler interventions that modify the instructions of the computer programme that controls the rotating means of the tensioning means.

Landscapes

• Controlling Rewinding, Feeding, Winding, Or Abnormalities Of Webs (AREA)
• Folding Of Thin Sheet-Like Materials, Special Discharging Devices, And Others (AREA)
• Basic Packing Technique (AREA)
• Advancing Webs (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (2)

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ID=46397469

Family Applications (1)

Country Status (6)

Cited By (7)

Families Citing this family (4)

Citations (2)

Family Cites Families (4)

• 2012
  • 2012-06-15 IT IT000155A patent/ITMO20120155A1/it unknown
• 2013
  • 2013-06-14 HU HUE13747506A patent/HUE041831T2/hu unknown
  • 2013-06-14 WO PCT/IB2013/054869 patent/WO2013186745A2/en not_active Ceased
  • 2013-06-14 PL PL13747506T patent/PL2861515T3/pl unknown
  • 2013-06-14 CN CN201380038953.0A patent/CN104661942B/zh active Active
  • 2013-06-14 EP EP13747506.7A patent/EP2861515B1/en active Active

Patent Citations (2)

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