Apparatus and method for converting sheets into continuous strip

Abstract

To provide an apparatus and a method for converting sheets into a continuous strip.SOLUTION: The present invention relates to an apparatus and a method for converting a sheet of elastomeric material into a continuous strip, the apparatus including a notching portion for providing a series of notches in the sheet that are capable of separating the sheet into interconnected zigzag portions to form a continuous strip; the sheet has two longitudinal edges, and the series of notches alternately extend from one of the longitudinal edges and terminate at a terminal distance from the other of the longitudinal edges to form a plurality of interconnected zigzag portions; and the notching portion includes a notching member for notching the sheet along a notching line intersecting a feed path, and a lateral edge sensor for detecting a lateral position of the longitudinal edge at a detection position upstream of the notching line relative to the feed direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an apparatus and method for converting a sheet into a continuous strip.

Background Art

[0002] International Publication No. 2017 / 171454 pamphlet discloses an apparatus and method for converting a sheet into a continuous strip, the sheet having a series of cuts extending in a cutting direction transverse to the sheet with respect to the longitudinal direction to form a plurality of interconnected sheet pieces, the continuous strip having a zigzag portion, the sheet pieces being arranged to be pulled apart in a supply direction to form the zigzag portion, the apparatus comprising a separating device having a holding device for holding an upstream sheet portion with respect to a downstream sheet portion continuous in the supply direction and a sensor device for detecting the pulling apart of the downstream sheet portion from the upstream sheet portion.

Summary of the Invention

[0003] The disadvantage of known apparatuses is that the sheet contains an elastomeric material which may have irregularities in shape, size and / or thickness. The lateral position of the longitudinal edges may be different due to the original shape of the sheet.

[0004] The object of the present invention is to provide an apparatus and method for converting a sheet into a continuous strip.

[0005] According to a first aspect, the present invention provides an apparatus for converting a sheet of elastomeric material into a continuous strip, the apparatus comprising a cutting portion for providing a series of cuts in the sheet, the cuts being separable in a zigzag portion where the sheets are interconnected to form a continuous strip, the sheet having two longitudinal edges, the series of cuts extending alternately from one of the longitudinal edges and terminating at a terminal distance away from the other longitudinal edge to form a plurality of interconnected zigzag portions, the cutting portion comprising a cutting member for cutting the sheet along a cutting line intersecting the supply path, and a lateral edge sensor for detecting a lateral position of the longitudinal edge at a detection position upstream of the cutting line with respect to the supply direction.

[0006] The lateral position of the longitudinal edge may vary depending on the original shape of the sheet. The lateral position of the longitudinal edge is detected to determine where to start or end the cuts in the series of cuts. By detecting the lateral position of the longitudinal edge upstream of the cutting line, the start or end position of the cuts for future cuts can be determined before the future cuts are started.

[0007] In one embodiment thereof, the apparatus is configured to provide the series of cuts at a cut interval, and the detection position is upstream of the cutting line at a detection distance from the cutting line equal to or greater than the cut interval. Thus, the lateral position of the longitudinal edge can be detected at a detection position related to subsequent cuts.

[0008] In another embodiment, the lateral edge sensor is arranged to move in a cutting direction parallel to the cutting line together with the cutting member. Specifically, the lateral edge sensor can be supported by, or relatively supported with respect to, a carriage that also transports the cutting member. By moving the lateral edge sensor together with the cutting member, both longitudinal edges can be detected using the same lateral edge sensor. More specifically, since the cutting member cuts the sheet from a position outside the sheet alongside one of its longitudinal edges, the lateral position of the one longitudinal edge can be detected simultaneously with the cutting member that cuts the sheet at the one longitudinal edge.

[0009] Preferably, the lateral edge sensor is disposed centrally with respect to the cutting member in the cutting direction. Since the lateral edge sensor is not used to control the cutting in real time, the lateral edge sensor does not need to detect the lateral position of the longitudinal edge in front of the cutting member in the cutting direction. Instead, the lateral position of the longitudinal edge can be detected at the current position of the cutting member along the cutting line. Therefore, only a single lateral edge sensor is required, and this sensor can be conveniently disposed centrally with respect to the cutting member and used to detect both longitudinal edges in the same way. This can make the apparatus less expensive and / or less complex.

[0010] In a further embodiment, the apparatus further comprises a control unit operatively connected to the lateral edge sensor for receiving a signal indicating one of the longitudinal edge positions at the detection position, the control unit being configured to associate a signal received from the lateral edge sensor during one of the series of cuts with a future cut to be made in the series of cuts. The signal or a value representative of the signal may be stored in a memory for later use, for example, to determine the start or end of the future cut to be made. More specifically, the control unit is configured to set an end distance of the future cut based on the signal from the lateral edge sensor.

[0011] According to a second aspect, the present invention provides a method for converting a sheet of elastomeric material into a continuous strip using the apparatus according to the first aspect of the present invention, the method comprising detecting a lateral position of the longitudinal edge at a detection position upstream of the cut line with respect to the supply direction.

[0012] Preferably, the series of cuts are provided at a cut interval, and the detection position is upstream of the cut line at a detection distance from the cut line equal to or greater than the cut interval.

[0013] In a further embodiment, the method further comprises associating a lateral position of the longitudinal edge detected at the detection position during one of the series of cuts with a future cut to be made in the series of cuts.

[0014] Preferably, the method further comprises setting an end distance of the future cut based on the lateral position of the longitudinal edge associated with the future cut.

[0015] According to a third non-claimed aspect, the present invention is an apparatus for converting a sheet of elastomeric material into a continuous strip, the apparatus comprising a cutting section for forming a series of separable cuts in the sheet into zigzag portions interconnecting the sheet to form the continuous strip, the apparatus further comprising a feeding section for feeding the sheet in a feeding direction along a supply path to the cutting section, the feeding section comprising a first feeding member for feeding the sheet along the supply path at a first feeding speed and a second feeding member downstream of the first feeding member for feeding the sheet along the supply path at a second feeding speed, the apparatus being operable in a stretching mode in which the second feeding speed is faster than the first feeding speed.

[0016] By providing a speed difference between the first feeding speed and the second feeding speed, the sheet can be stretched between the first feeding member and the second feeding member. This stretching can reduce, flatten, or smooth irregularities such as folds and wrinkles in the sheet. Thus, the risk of blockage and / or jamming of the apparatus as a result of such irregularities can be reduced.

[0017] In a preferred embodiment, the apparatus comprises a first drive section for driving one of the first feeding member and the second feeding member, and the apparatus further comprises a transmission between the first feeding member and the second feeding member for driving the other of the first feeding member and the second feeding member at a transmission ratio such that the second feeding speed is faster than the first feeding speed. Thus, only one of the feeding members needs to be driven.

[0018] Alternatively, the apparatus includes a first driving unit for driving the first feeding member, a second driving unit for driving the second feeding member, and a control unit operatively connected to the first driving unit and the second driving unit for controlling the second feeding speed to be higher than the first feeding speed in the stretching mode. By controlling both driving units, a variable ratio between the first feeding speed and the second feeding speed can be set and / or adjusted during the stretching mode, or alternatively, it can be switched to a non-stretching mode where the feeding speeds are equal.

[0019] In another embodiment, the first feeding member includes a first driven roll and a first driving unit for rotating the first driven roll, and the apparatus includes a control unit operatively connected to the first driving unit for rotating the first driven roll at a peripheral speed corresponding to the first feeding speed in the stretching mode. The rotation of the first driven roll can be directly or indirectly applied or transmitted to the sheet to move the sheet at the first feeding speed.

[0020] Preferably, the first feeding member includes a conveyor belt for conveying the sheet along the supply path, and the first driven roll is arranged to drive the conveyor belt. The first feeding member may be, for example, a head pulley or a tail pulley for driving the conveyor belt.

[0021] More preferably, the apparatus further includes a pressing member for pressing the sheet on the conveyor belt in the pressing direction. The pressing can increase the friction between the sheet and the conveyor belt and prevent the sheet from slipping relative to the conveyor belt. Thus, the first feeding speed can be reliably imposed on the sheet.

[0022] More preferably, the pressing direction is the vertical direction, and the pressing member is freely movable in the pressing direction under the influence of gravity. Thus, the weight of the pressing member can be utilized to apply a pressing force to the sheet. In other words, a driving unit for driving the pressing member is not required.

[0023] In a further embodiment, the pressing member comprises a pressing roll. The pressing roll can roll on the sheet when the sheet is advanced and / or conveyed along the supply path.

[0024] In another embodiment, the second feeding member comprises a second driven roll, and the second driven roll is arranged to rotate at a peripheral speed corresponding to the second feeding speed in the stretching mode. The rotation of the second driven roll can be imparted or transmitted directly or indirectly to the sheet to move the sheet at the second feeding speed.

[0025] In another embodiment, the second feeding member comprises a pair of calendar rolls that define an entry nip for receiving the sheet in the supply direction and an exit nip for further feeding the sheet in the supply direction along the supply path. The pair of calendar rolls can further flatten and / or smooth the irregularities of the sheet before the sheet reaches the cutting portion.

[0026] It should be noted that any of the embodiments of the pair of calendar rolls, and the embodiments related to the pair of calendar rolls described below, can be applied in more detail regardless of the apparatus and, more particularly, regardless of any of the aforementioned feeding speeds.

[0027] In particular, in one embodiment of the pair of calendar rolls, at least one of the pair of calendar rolls is driven. The at least one calendar roll can further pull or feed the sheet along the supply path towards the cutting portion.

[0028] In another embodiment, one of the pair of calendar rolls is rotatable about a first roll axis and is movable along a calendar direction perpendicular to the first roll axis, either towards or away from the other calendar roll of the pair of calendar rolls. By moving one calendar roll towards the other calendar roll, the pair of calendar rolls can be positioned at a location for calendaring the sheet. More specifically, the distance between the pair of calendar rolls can be adjusted and / or the pressure exerted on the sheet by the pair of calendar rolls can be controlled. By moving one calendar roll away from the other calendar roll, the opening between the pair of calendar rolls can be opened to allow removal or insertion of the sheet, for example, at the start or maintenance of the apparatus.

[0029] Preferably, the apparatus includes an actuator for pressing the one calendar roll along the calendar direction towards the other calendar roll. This actuator can be used, for example, to apply a predetermined, variable or constant pressing force to the sheet.

[0030] More preferably, the actuator is further arranged to move the one calendar roll away from the other calendar roll. The actuator may be, for example, movable in both directions. Once one calendar roll moves away, the pair of calendar rolls becomes accessible for removal or insertion of the sheet.

[0031] In a further embodiment, the pair of calendar rolls includes a first calendar roll having a plurality of first disks arranged coaxially with the first roll axis and rotatable about the first roll axis, the second feeding member includes one or more first guide bodies interposed between the plurality of first disks in an axial direction parallel to the first roll axis, and the one or more first guide bodies protrude into a guide region on the downstream side of the nip for advancement of the pair of calendar rolls. The sheet includes an elastomeric material that easily adheres to the circumferential surface of the first calendar roll when the pair of calendar rolls is at the position of the nip for advancement. By providing one or more first guide bodies in the region of the nip for advancement, it is possible to prevent the sheet from being pulled along the circumferential surface of the first calendar roll. The one or more first guide bodies can continuously force the sheet to follow the supply path. In particular, the one or more first guide bodies can function as a scraper that scrapes the sheet from the circumferential surface of the first calendar roll at the nip for advancement.

[0032] In one embodiment thereof, the one or more first guide bodies protrude beyond the plurality of first disks into a square region including a quadrant of the plurality of first disks, the square region extending to the supply path and being located downstream of the first roll axis. The risk that the sheet is pulled along the circumference of the first calendar roll exists within the square region. Therefore, by providing one or more first guide bodies within the square region, such pulling can be prevented.

[0033] In another embodiment thereof, each of the one or more first guide bodies includes a first guide surface for guiding the sheet along the supply path on the downstream side of the first calendar roll. The first guide surface can be arranged to directly contact the sheet and guide the sheet.

[0034] Preferably, the first guide surface is spaced apart from the supply path that is considered to be in the supply direction. The purpose of the first guide surface is to loosely guide the sheet along the supply path. It is not intended for the first guide surface to tightly sandwich or press the sheet. In particular, unnecessary friction between the first guide surface and the sheet should be prevented. Therefore, by arranging the first guide surface in a direction away from the supply path in the supply direction, instead of restricting the freedom of movement of the sheet with respect to the supply path, the first guide surface can be opened or widened with respect to the feed path.

[0035] In another embodiment, the one or more first guide bodies include a plurality of first guide bodies, and the plurality of first guide bodies are alternately arranged with the plurality of first disks in the axial direction. Accordingly, the sheet can be guided along the guide path at the nip for advancement at two or more positions along the first calendar roll.

[0036] In another embodiment, each first disk of the plurality of first disks has a disk width in the axial direction, and each first guide body of the one or more first guide bodies has a guide body width smaller than the disk width in the axial direction. Due to the relatively large disk width, the first calendar roll can apply pressure to the sheet more uniformly, that is, over a larger contact surface area between the plurality of first disks and the sheet.

[0037] In another embodiment, in the entry nip, the one or more first guide members are in a retracted position relative to the plurality of first disks. Thereby, the plurality of first disks can effectively press the sheet in the entry nip while reducing or preventing contact and / or pressure between the sheet and the one or more first guide members. In particular, considering that the elastomeric material of the sheet may be slightly pushed into the area between the respective first disks, the one or more first guide members may be in a sufficiently retracted position so as to remain separated from the sheet even when the sheet is slightly pushed against the first calendar roll.

[0038] In another embodiment, the one or more first guide members are fixed relative to the first roll axis. Thus, the one or more first guide members can be arranged in a posture fixed relative to the supply path.

[0039] In another embodiment, the apparatus includes a holder for holding the first calendar roll and the one or more first guide members, and the holder is movable in a calendar direction perpendicular to the first roll axis. Thus, the first calendar roll and the one or more first guide members can be moved together or integrally by the holder, for example, to access a pair of calendar rolls for sheet removal or insertion, or for maintenance.

[0040] In another embodiment, the pair of calendar rolls includes a second calendar roll having a plurality of second disks rotatable about a second roll axis coaxial with the first roll axis, the second feeding member includes one or more second guide members interposed between the plurality of second disks in the axial direction, and the one or more second guide members project toward the supply path on the downstream side of the second calendar roll beyond the plurality of second disks. The one or more first guide members and the one or more second guide members can together continue to guide the sheet along the supply path from opposite sides of the supply path.

[0041] In a further embodiment, each of the one or more first guide members faces each of the one or more second guide members in a calender direction perpendicular to the first roll axis. Thus, a set of two opposing guide members can effectively define a guide channel through which the sheet passes after exiting a pair of calender rolls.

[0042] In another embodiment, each of the one or more first guide members comprises a first guide surface for guiding the sheet along the supply path downstream of the pair of calender rolls, and each of the one or more second guide members comprises a second guide surface for guiding the sheet along the supply path downstream of the pair of calender rolls, and the first guide surface is spaced apart from the second guide surface which is considered to be in the supply direction. By arranging the first guide surface and the second guide surface to be relatively spaced apart in the supply direction, instead of restricting the freedom of movement of the sheet with respect to the supply path, the guide channel defined between the guide surfaces can be opened or widened with respect to the supply path.

[0043] In another embodiment, although it can also be applied regardless of the aforementioned feeding member and feeding speed, the apparatus further comprises an irregularity sensor for detecting irregularities of the sheet upstream of the second feeding member. The irregularity sensor can be used to detect irregularities above a predetermined threshold, for example, irregularities that are likely to cause problems such as blockages or jams, despite countermeasures taken downstream of the irregularity sensor. The apparatus may be stopped to allow human intervention.

[0044] In another embodiment, although it can also be applied regardless of the aforementioned feeding member and feeding speed, the feeding unit further includes one or more input rollers for holding the sheet within the apparatus, and the one or more input rollers are rotatable only in one direction. Accordingly, the one or more input rollers can hold or support the leading end of the sheet within the apparatus, while preventing the leading end from inadvertently exiting the apparatus in a direction opposite to the feeding direction.

[0045] Preferably, the feeding unit includes one or more swing arms for supporting the one or more input rollers with respect to the supply path, and an irregularity sensor for detecting a parameter indicating the position and / or orientation of the one or more input rollers or the one or more swing arms with respect to the supply path. The one or more swing arms enable the one or more input rollers to be pressed against the sheet by their own weight. When irregularities occur in the sheet, the one or more input rollers and the associated one or more swing arms are lifted, and the orientation and / or position of these components can be used to activate the irregularity sensor.

[0046] In another embodiment, although it can also be applied regardless of the aforementioned feeding member and feeding speed, the cutting unit includes a cutting member for cutting the sheet along a cutting line that intersects the supply path, and the supply path and the cutting line extend within a supply plane that is within a range of 0 degrees to 10 degrees with respect to a vertical plane at their intersection portion. Preferably, the supply plane extends vertically. In the vertical or substantially vertical direction of the supply plane, gravity can assist in separating the continuous strip of the interconnected zigzag portions.

[0047] In another embodiment, although it can also be applied regardless of the aforementioned feeding member and feeding speed, the cutting portion includes a cutting member and an anvil that cooperate to cut the sheet along the cutting line that intersects the supply path. The cutting member is movable up to and in contact with the anvil in a cutting direction perpendicular to the supply path and the cutting line. The cutting portion further includes a damper for mitigating the impact between the cutting member and the anvil in the cutting direction. By mitigating or buffering the impact, wear of the cutting member as a result of the impact can be reduced.

[0048] In another embodiment, the supply path between the first feeding member and the second feeding member extends within a range of 0 degrees to 30 degrees with respect to the vertical plane. In such a direction, irregularities of the sheet can be reduced under the influence of gravity.

[0049] In another embodiment, the apparatus defines a free section of the supply path where the sheet is not supported from the first feeding member to the second feeding member. In other words, the sheet can freely extend between the respective feeding members. In this free section, irregularities of the sheet can be reduced under the influence of gravity.

[0050] In another embodiment, although it can also be applied regardless of the aforementioned feeding member and feeding speed, the apparatus includes a delivery portion having a delivery opening for delivering the continuous strip out of the apparatus. The delivery portion further includes a direction-changing member for changing the direction of the continuous strip toward the delivery opening. When supplying a new continuous strip through the apparatus, the leading end portion of the new continuous strip may be in a position that is difficult to reach from outside the apparatus. This direction-changing member can be used to conveniently move the leading end portion within a range reachable by a human operator or a mechanical gripper at the delivery opening.

[0051] Preferably, the direction conversion member has a manually operable lever. The manually operable lever may be disposed at a safely accessible position, for example, outside the housing of the device.

[0052] According to a fourth non-claimed aspect, the present invention provides a method for converting a sheet of elastomeric material into a continuous strip using the device according to any one of the embodiments of the third aspect of the present invention, the method comprising: · feeding the sheet at the first feeding speed along the supply path by the first feeding member, and · feeding the sheet at the second feeding speed along the supply path by the second feeding member including.

[0053] This method relates to the practical application of the device according to the third aspect of the present invention and therefore, although not repeated below, has the same technical advantages.

[0054] The various aspects and features described and shown herein can be applied individually as much as possible. These individual aspects, particularly those described in the appended dependent claims, can be the subject of a divisional patent application.

Brief Description of the Drawings

[0055] The present invention will be described based on exemplary embodiments shown in the appended schematic diagrams.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 6

Figure 7

[0056] FIGS. 1 and 2 show an apparatus 1 for converting an elastomeric material, particularly a rubber sheet 8, into a continuous strip 9 according to a first exemplary embodiment of the present invention. The continuous strip 9 is used as an input material for an extruder. The sheet 8 is supplied to the apparatus 1 as a continuous length. The sheet 8 may be stacked in several layers on a pallet. The sheet 8 may be made of a material having irregularities and / or inconsistencies such as folds, wrinkles, thickness variations, irregular edges and / or width variations.

[0057] As shown in FIG. 2, the sheet 8 has a first longitudinal edge 81 and a second longitudinal edge 82. The apparatus 1 is provided with a cut portion 5 adapted, arranged, and / or configured to form a series of cuts C1, C2, C3,..., Cn in the sheet 8 along which the sheet 8 is separable into interconnected zigzag portions 91, 92, 93, 94. In particular, the series of cuts C1, C2, C3,..., Cn extend alternately from one of the longitudinal edges 81, 82 to the other and terminate at a terminal distance T away from the other of the longitudinal edges 81, 82 to form a plurality of interconnected zigzag portions 91, 92, 93, 94.

[0058] As best shown in FIG. 1, the apparatus 1 includes a feeding unit 2 for feeding the sheet 8 along the feeding direction F to the cutting unit 5. The apparatus 1 further includes a discharging unit 6 for discharging the continuous strip 9 from the apparatus 1. The sheet 8 and the continuous strip 9 move along a supply path P, a part of which is shown in FIG. 2. When the supply path P is not visible in the drawing, for example in FIG. 1, it is understood that the path along which the sheet 8 and the continuous strip 9 move through the apparatus 1 corresponds to or coincides with the supply path P.

[0059] As shown in FIG. 1, the feeding unit 2 includes one or more input rollers 21 for holding the sheet 8 within the apparatus 1 when the leading edge of the sheet 8 is fed into the apparatus 1. In this example, to prevent the sheet 8 from slipping back out of the apparatus 1 in the direction opposite to the feeding direction F, the one or more input rollers 21 are rotatable only in one direction.

[0060] In this exemplary embodiment, the feeding unit 2 includes one or more swing arms 22 for supporting the one or more input rollers 21 relative to the supply path P. The one or more input rollers 21 freely move under their own weight towards the sheet 8 and rest on the sheet 8. Additionally or alternatively, the one or more input rollers 21 may be moved towards or away from the supply path P, for example in an automated or semi-automated manner. Thus, the operator can keep at least one hand free to guide the continuous strip 9 into the feeding unit 2.

[0061] The feeding unit further includes a first feeding member 3 for feeding the sheet 8 along the supply path P toward the cutting unit 5, and a second feeding member 4 located downstream of the first feeding member 3 in the supply direction F. The first feeding member 3 and the second feeding member 4 are arranged at intervals along the supply path P. In this example, the apparatus 1 defines a free section of the supply path P where the sheet 8 is not supported from the first feeding member 3 to the second feeding member 4. The supply path P extends at a relatively steep downward angle, particularly within the range of 0 degrees to 30 degrees, with respect to the vertical plane in the free section.

[0062] The first feeding member 3 is adapted, arranged or configured to feed the sheet 8 along the supply path P at a first feeding speed V1. The second feeding member 4 is adapted, arranged or configured to feed the sheet 8 along the supply path P at a second feeding speed V2 different from the first feeding speed V1. The apparatus 1 is operable in a stretching mode where the second feeding speed V2 is faster than the first feeding speed V1. In particular, the second feeding speed V2 is at least 5% faster than the first feeding speed V1, preferably at least 10% faster.

[0063] The first feeding member 3 includes a first driven roll 31 adapted, arranged or configured to be driven or rotated at a peripheral speed corresponding to the first feeding speed V1 in the stretching mode. Accordingly, the first driven roll 31 imparts the first feeding speed V1 to the sheet 8. In this example, the first driven roll 31 indirectly imparts the first feeding speed V1 to the sheet 8. In particular, the first feeding member 3 further includes a conveyor belt 32 for conveying the sheet 8 along the supply path P. The first driven roll 31 is one of the pulleys, particularly the head pulley, for driving the conveyor belt 32. Accordingly, the first driven roll 31 can drive the conveyor belt 32 to operate at the first feeding speed V1.

[0064] In this embodiment, the load-bearing side of the conveyor belt 32 extends horizontally or substantially horizontally, that is, within the range of 0 degrees to 10 degrees with respect to the horizontal plane.

[0065] The second feeding member 4 includes a second driven roll 42 adapted, arranged or configured to be driven or rotated at a peripheral speed corresponding to the second feeding speed V2 in the stretching mode. In this example, the second driven roll 42 is part of a pair of calendar rolls 41, 42. The pair of calendar rolls 41, 42 includes a first calendar roll 41 and a second calendar roll 42. The pair of calendar rolls 41, 42 and their related aspects will be described in more detail below, but can be claimed independently from the entire apparatus 1. Therefore, hereinafter, the second driven roll 42 may be referred to as both the "second driven roll" and the "second calendar roll", and the latter is not limited by the word "driven".

[0066] As schematically shown in FIG. 1, the apparatus 1 includes a first drive unit 11 for driving the first driven roll 31 and a transmission 12 between the first driven roll 31 and the second driven roll 42 for driving the second driven roll 42. The transmission 12 may be formed by a chain or a timing belt. Alternatively, a gear or other suitable type of transmission may be used. The transmission 12 is configured to obtain a transmission ratio such that the second feeding speed V2 is faster than the first feeding speed V1 between the first feeding member 3 and the second feeding member 4. The first drive unit 11 may alternatively be configured to directly drive the second driven roll 42, in which case it will be understood by those skilled in the art that the transmission 12 will drive the first driven roll 11.

[0067] The apparatus 1 further includes a control unit 7 operatively, electronically and / or functionally connected to the first drive unit 11 to control the peripheral speed of the first driven roll 31 in the stretching mode.

[0068] As further shown in FIG. 1, the apparatus 1 includes a pressing member 23 for pressing the sheet 8 on the conveyor belt 32 in the pressing direction D. In this embodiment, the pressing member 23 includes a pressing roll 24 that can roll over the sheet 8 as the sheet 8 moves downward. Further, in this example, the pressing direction D is vertical or substantially vertical. The pressing member 23 is freely movable, for example, within a vertical slot of the frame of the apparatus 1, under the influence of gravity in the pressing direction D. In other words, the pressing member 23 can be pressed against the sheet 8 by its own weight. In contrast to what is shown in FIG. 1, the pressing member 23 may be arranged directly opposite the first driven roll 31 or another roller or pulley of the feeding member 3 so as to more reliably press the continuous belt-like body 9.

[0069] As shown in FIGS. 1 and 2, the feeding section 2 further includes one or more feeding guides 27, 28, 29 arranged outside the supply path P, where the sheet 8 is deflected downward toward the cutting section 5 within the free section of the supply path P. As best seen in FIG. 1, the one or more feeding guides 27, 28, 29 have an arcuate inner surface that can deflect and / or guide the sheet 8 downward when the sheet 8 itself cannot deflect downward under its own weight. Further, the one or more feeding guides 27, 28, 29 can reliably limit the unpredictable movement of the rear end of the sheet 8 toward and / or into the cutting section 5 when the rear end of the sheet 8 is no longer held and / or controlled by the first feeding member 3.

[0070] As shown in Fig. 1, the first calendar roll 41 and the second calendar roll 42 are each rotatable about a first roll axis R1 and a second roll axis R2, respectively. The roll axes R1 and R2 are parallel or substantially parallel to each other. The first calendar roll 41 is movable in the calendar direction X perpendicular to the first roll axis R1, toward and away from the second calendar roll 42. In this embodiment, the feeding unit 2 includes a holder 26 for holding the first calendar roll 41 with respect to the second calendar roll 42. The holder 26 is swingable about a pivot axis B parallel to and spaced from the first roll axis R1 in order to move the first calendar roll 41 in the calendar direction X.

[0071] In this embodiment, one or more of the aforementioned feeding guides 27, 28, 29 form part of and / or are integrated with the holder 26. Accordingly, the feeding guides 27, 28, 29 can move toward and away from the supply path P about the pivot axis B together with the first calendar roll 41.

[0072] The apparatus 1 further includes an actuator 15 for pressing the first calendar roll 41 toward the other calendar roll 42 in the calendar direction X. In this example, the actuator 15 acts indirectly on the first calendar roll 41 via the holder 26. The actuator 15 may be bidirectional, which means that the first calendar roll 41 can be moved away from the second calendar roll 42, for example, to insert and remove the sheet 8 and / or for maintenance.

[0073] A pair of calendar rolls 41, 42 are shown in more detail by FIGS. 3 and 4. In particular, FIG. 3 shows that a pair of calendar rolls 41, 42 define an entry nip N1 for receiving the sheet 8 in the supply direction F. The "entry nip" N1 is interpreted as the entrance between the pair of calendar rolls 41, 42, where the pair of calendar rolls 41, 42 "bite into" the sheet 8 as the sheet 8 is moved or pulled through the pair of calendar rolls 41, 42. The pair of calendar rolls 41, 42 further define an exit nip N2 for further feeding the sheet 8 in the supply direction F along the supply path P. Similarly, the "entry nip" N1 is interpreted as the exit point between the pair of calendar rolls 41, 42 where the sheet 8 exits the pair of calendar rolls 41, 42.

[0074] In this embodiment, as shown in FIG. 3, the supply path P extends vertically or substantially vertically at the exit nip N2, that is, within a range of 0 to 10 degrees with respect to the vertical plane. In particular, a vertical or substantially vertical supply plane Z can be defined at the pair of calendar rolls 41, 42 so as to extend through the exit nip N2 and in a direction parallel to the supply direction F, the supply path P and / or the first roll axis R1.

[0075] As best shown in FIG. 4, the first calendar roll 41 includes a plurality of first disks 43 that are coaxially arranged with the first roll axis R1 and are rotatable about the first roll axis R1. Similarly, the second calendar roll 42 includes a plurality of second disks 46 that are coaxially arranged with the second roll axis R2 and are rotatable about the second roll axis R2. Further, the first calendar roll 41 includes a plurality of first guide bodies 44 interposed between the plurality of first disks 43 in the axial direction A parallel to the first roll axis R1. Similarly, the second calendar roll 42 includes a plurality of second guide bodies 47 interposed between the plurality of second disks 46 in the axial direction A. In particular, in the axial direction A, the first guide bodies 44 are alternately arranged with the first disks 43, and the second guide bodies 47 are alternately arranged with the second disks 46. It should be noted that in this embodiment, each first guide body 44 is arranged opposite to each one of the second guide bodies 47 in the calendar direction X.

[0076] The first guide body 44 is fixed to the first roll axis R1 or adjacent to the first roll axis R1. In other words, the first guide body 44 is arranged to remain stationary while the first disk 43 rotates about the first roll axis R1. In particular, the first guide body 44 is formed as a plate fixed to a holder 26 that holds the first calendar roll 41. In this embodiment, the first guide body 44 has a U shape that can be fitted onto the shaft 40 of the first calendar roll 41.

[0077] Each of the disks 43, 46 has a disk width W1 in the axial direction A, and each of the guide bodies 44, 47 has a guide body width W2 that is smaller than the disk width W1 in the axial direction A. In particular, the guide body width W2 is less than 80% of the disk width W1, and more preferably less than 60%.

[0078] As shown in FIG. 3, the first guide body 44 protrudes into a guide region G on the downstream side of the nip N2 for the advancement of the pair of calendar rolls 41 and 42. This guide region G corresponds to and / or overlaps with the remaining space between the calendar rolls 41 and 42 immediately downstream of the advancement nip N2. By providing the first guide body 44 in the guide region G, it is possible to prevent the sheet 8 from being pulled along the circumferential surface of the first calendar roll 41. Specifically, the first guide body 44 protrudes into a square region S including the quadrant Q of the plurality of first disks 43 beyond the plurality of first disks 43. The square region S extends to the supply path P and / or the supply plane Z and is located on the downstream side of the first roll axis R1.

[0079] As further shown in FIG. 3, each first guide body 44 includes a first guide surface 45 for guiding the sheet 8 along the supply path P on the downstream side of the first calendar roll 41. The first guide surface 45 is inclined so as to change direction from the supply path P considered to be in the supply direction F or to move away from the supply path P. At the entry nip N1, the first guide body 44 is in a retracted position with respect to the first disk 43. In particular, the first guide surface 45 has an arcuate or circular cross-section having a radius smaller than the radius of the first disk 43. Preferably, the first guide body 44 is retracted by a distance of at least 1 millimeter, more preferably at least 2 millimeters, from the outer periphery of the first disk 43 at the entry nip N1.

[0080] The second guide body 47 also extends into the aforementioned guide region G from the opposite side of the supply path P and / or the supply plane Z. Each second guide body 47 includes a second guide surface 48 that faces the first guide surface 45 from the opposite side of the supply path P and / or the supply plane Z. The opposing guide surfaces 45, 48 form or define a guide channel for the sheet 8 at the advancing nip N2 and can further guide the sheet 8 along the supply path P. In particular, the first guide surface 45 and the second guide surface 48 are spaced apart from each other in the supply direction F. Therefore, the guide channel formed between the opposing guide surfaces 45, 48 is open or widened with respect to the supply path P.

[0081] It should be noted that the first guide body 44 and the second guide body 47 may have the same shape and / or dimensions and may be interchangeable.

[0082] Figures 5A and 5B show the cut portion 5 in more detail. The cut portion 5 includes a cutting member 51 for cutting the sheet 8 in the cutting direction C along a cutting line K that intersects the supply path P, as shown in Figure 6. In this example, as shown in Figure 5A, the cutting member 51 is a cutting disk that is rotatable about a cutting axis M parallel to the supply path P, the supply plane Z, and / or the supply direction F at the cutting line K. The cut portion 5 further includes a carriage 50 for moving the cutting member 51 relative to the cutting line K and a cutting drive unit 54 for driving or moving the carriage 50 in the cutting direction C along the cutting line K.

[0083] The cutting portion 5 includes an anvil 52 that cooperates with a cutting member 51 to cut the sheet 8 along the cutting line K. The anvil 52 is located on the side opposite to the cutting member 51 with respect to the supply path P and / or the supply plane Z. As shown by comparison in FIGS. 5A and 5B, the cutting member 51 is movable so as to contact the anvil 52 in a cutting direction H perpendicular to the supply path P, the supply plane Z, and / or the cutting line K. The cutting portion 5 further includes a damper 53 for absorbing, buffering, and / or alleviating the impact between the cutting member 51 and the anvil 52 in the cutting direction H. In particular, the cutting member 51 is movable along a cutting stroke in the cutting direction H, and the damper 53 is configured to alleviate the impact at the end of the cutting stroke.

[0084] As further shown in FIGS. 5A and 5B, the supply plane Z at the intersection of the supply path P and the cutting line K is perpendicular or substantially perpendicular, that is, within a range of 0 degrees to 10 degrees with respect to the vertical plane.

[0085] As shown in FIG. 1, the feeding portion 6 includes a feeding opening 61 in the housing of the apparatus 1 for feeding out the continuous strip 9 from the apparatus 1. Since the supply plane Z in the cutting portion 5 is perpendicular or substantially perpendicular, the tip of the continuous strip 9 tends to fall onto the floor surface of the apparatus 1. Therefore, when starting the cutting operation and when a new tip is generated on the continuous strip 9, the tip must be guided toward and through the feeding opening 61. Since it is difficult or potentially dangerous to insert a hand into the apparatus 1 during operation, the feeding portion 6 further includes a direction-changing member 62 for changing the direction of the continuous strip 9 toward the feeding opening 61. In this embodiment, the direction-changing member 62 includes a manually operable lever 63. The manually operable lever 63 may be arranged at a safely accessible position outside the housing of the apparatus 1.

[0086] As shown in FIG. 1, the apparatus 1 further comprises an irregularity sensor 71 for detecting parameters indicating the position and / or orientation of one or more input rollers 21 or one or more swing arms 22 with respect to the supply path P. In particular, the irregularity sensor 71 may be a photocell for detecting a light beam extending over one or more input rollers 21 and / or one or more swing arms 22 when the one or more input rollers 21 are in a normal position. However, when the one or more input rollers 21 are displaced by the upward irregularities of the sheet 8, the one or more input rollers 21 or one or more swing arms 22 associated therewith block the light beam, and this blockage can be used to indicate that the irregularity has passed the position of the one or more input rollers 21. The irregularity sensor 71 is operationally, electronically and / or functionally connected to the control unit 7. When receiving a signal from the irregularity sensor 71, the control unit 7 can stop the apparatus 1 and request human intervention.

[0087] Alternatively, the irregularity sensor 71 may be arranged further downstream of the one or more input rollers 21, for example, at a predetermined height above the conveyor belt 32 to directly detect irregularities in the sheet 8, or arranged on the pressing member 23 to detect irregularities as a function of the height of the pressing member 23. The irregularity sensor 71 is arranged upstream of the second feeding member 4 to prevent irregularities exceeding a predetermined threshold from accumulating on the pair of calendar rollers 41, 42.

[0088] As shown in FIG. 6, the longitudinal edges 81, 82 of the sheet 8 may have a slightly irregular shape. Thus, the lateral positions E1, E2 of the respective longitudinal edges 81, 82 may vary slightly for each of the series of cuts C1, C2, C3, ..., Cn in the series of cuts C1, C2, C3, ..., Cn. The apparatus 1 comprises a lateral edge sensor 72 for detecting the lateral positions E1, E2 of the longitudinal edges 81, 82. The detected lateral positions E1, E2 can be used to determine appropriate start, end, cut length and / or end distance T so that each of the cuts C1, C2, C3, ..., Cn in the series of cuts C1, C2, C3, ..., Cn can end at a position spaced from the respective longitudinal edges 81, 82.

[0089] The lateral edge sensor 72 is arranged at a detection position L upstream of the cut line K with respect to the supply direction F. In particular, the apparatus 1 is configured to form the cuts C1, C2, C3, ..., Cn in sequence with a cut interval I. In other words, the sheet 8 is advanced between the cuts C1, C2, C3, ..., Cn over a distance in the supply direction F equal to the cut interval I. The detection position L is upstream of the cut line K at a detection distance J from the cut line K equal to the cut interval I. Alternatively, the detection distance J may be greater than the cut interval I, preferably a multiple of the cut interval I.

[0090] In this particular embodiment, the lateral edge sensor 72 is arranged to move with the cutting member 51 in the cutting direction C. More specifically, the lateral edge sensor 72 is attached to or carried by the same carriage 50 that mounts the cutting member 51. The lateral edge sensor 72 is centrally arranged with respect to the cutting member 51 in the cutting direction C. In other words, the lateral edge sensor 72 is symmetrically arranged with respect to the cutting member 51 in the cutting direction C. Thus, the lateral edge sensor 72 can detect the longitudinal edges 81, 82 on both sides of the sheet 8 in substantially the same manner.

[0091] The lateral edge sensors 72 are operatively, electronically, and / or functionally connected to the control unit 7 in order to transmit signals indicating the lateral positions E1, E2 of the respective longitudinal edges 81, 82 to the control unit 7. The control unit 7 is configured to associate the signal received from the lateral edge sensor 72 during one of the series of cuts C1, C2, C3, ..., Cn with a future cut C2 of the series of cuts C1, C2, C3, ..., Cn that is scheduled to be performed in the future. The signal or the value indicating the signal may be stored, for example, in a memory, particularly a non-transitory memory, for later use. The control unit 7 is further configured to set a terminal distance T for the future cut C2 based on the signal from the lateral edge sensor 72.

[0092] As shown in FIG. 1, the apparatus 1 further comprises a first tip sensor 73 for detecting when the tip of the continuous strip 9 passes the position of the first tip sensor 73. In this embodiment, the first tip sensor 73 is arranged between the feeding unit 2, particularly one or more feeding rollers 21 and the pressing member 23. Alternatively, the function of the first tip sensor 73 may be integrated into one or more feeding rollers 21 or the pressing member 23. The first tip sensor 73 is operatively, functionally, and / or electronically connected to the control unit 7 in order to transmit a signal indicating the detection of the tip to the control unit 7. In this embodiment, the first tip sensor 73 comprises a detection roller 74 for rolling on the continuous strip 9. When the tip reaches the detection roller 74, it is lifted from the surface of the conveyor belt 32, and this lifting is detected as indicating the arrival of the tip.

[0093] The control unit 7 can further receive a signal from an encoder for tracking how much of the length of the continuous strip 9 has passed the position of the first tip sensor 73 in order to theoretically determine when the tip reaches the cut portion 5. In this embodiment, the encoder is coupled to the detection roller 74 to detect the rotation of the detection roller 74. This has the additional technical advantage that it can measure the length of the continuous strip 9 passing through more accurately compared to an encoder associated with the conveyor belt 3, especially since the detection roller 74 also rolls over waves, wrinkles or folds of the continuous strip 9 and thus includes the length of the continuous strip 9 in the wavy, wrinkled or folded portion in its measurement value.

[0094] It should be noted that the second tip sensor 75 may be provided in or on the opposite side of the cut portion 5, for example, the anvil 52, to detect whether the tip has actually arrived at the cut portion 5 as expected. In particular, the second tip sensor 75 detects whether the continuous strip 9 is present on the cut line K or downstream of the cut line K. If there are folds or wrinkles that deflect the continuous strip 9 from its supply path P, the tip may not pass through the cut line K. Theoretically, if the tip is not detected when it should have reached the cut portion 5, it is considered that something has gone wrong and the device 1 is stopped.

[0095] FIG. 7 shows an alternative device 101 according to a second exemplary embodiment of the present invention, which differs from the device 1 described above only in that the transmission 12 is replaced by a second drive unit 112 controlled by the control unit 7 in relation to the first drive unit 111 such that the second feeding speed V2 is faster than the first feeding speed V1. By supplying the individual drive units 111, 112, the ratio between the first feeding speed V1 and the second feeding speed V2 can be adjusted or changed according to requirements.

[0096] Next, a method for converting the sheet 8 of the elastomer material into a continuous strip 9 using the aforementioned apparatuses 1 and 101 will be briefly described with reference to FIGS. 1 to 4, 5A, 5B, and 6.

[0097] As shown in FIGS. 1 and 2, the sheet 8 is supplied along the supply path P in a state where the first feeding member 3 imparts the first feeding speed V1 to the sheet 8 and the second feeding member 4 imparts the second feeding speed V2 to the sheet 8. By providing a speed difference between the first feeding speed V1 and the second feeding speed V2, the sheet 8 is stretched between the first feeding member 3 and the second feeding member 4. Due to this stretching, irregularities such as folds and wrinkles of the sheet 8 can be reduced, flattened, or smoothed. Therefore, as a result of such irregularities, the risk of blockage and / or clogging of the apparatuses 1 and 101 can be reduced.

[0098] As shown in FIGS. 5A and 5B, the cutting member 51 is reciprocated in the cutting direction H to form a series of cuts C1, C2, C3,..., Cn, as best shown in FIG. 6. In particular, as shown in FIG. 6, the cutting member 51 is positioned outside the sheet 8 along the first longitudinal edge 81 and starts the first cut C1 by cutting through the sheet 8 through the first longitudinal edge 81. When the terminal distance T is reached, the cutting member 51 is pulled back in a direction opposite to the cutting direction H to prevent the cutting member 51 from cutting further into the sheet 8 beyond the terminal distance T. Therefore, the first zigzag portion 91 formed by the first cut C1 remains connected to both the sheet 8 and the future zigzag portions 92 to 94 to be cut.

[0099] When the cutting member 51 starts the first cut C1, it should be noted that the lateral edge sensor 72 has already detected the lateral position E1 of the first longitudinal edge 81 at the detection position L upstream of the cutting line K. In particular, the lateral position E1 is detected at the position where the future second cut C2 of the series of cuts C1, C2, C3, ..., Cn is made after the first cut C1 is completed. The lateral position E1 is used to determine by a computer the end distance T of the second cut C2 or a parameter related to the end distance T. Similarly, when starting the second cut C2 at the second longitudinal edge 82, it should be noted that the lateral edge sensor 72 can already detect the lateral position E2 of the second longitudinal edge 82 for the purpose of determining or calculating the end distance T of the future third cut C3 of the series of cuts C1, C2, C3, ..., Cn or a parameter related to the end distance T. This process can be repeated for all of the series of cuts C1, C2, C3, ..., Cn.

[0100] It should be understood that the above description is included to explain the operation of the preferred embodiment and is not intended to limit the scope of the present invention. From the above discussion, many variations that would be encompassed within the scope of the present invention will be apparent to those skilled in the art.

Explanation of Reference Numerals

[0101] 1 Device 11 First Driving Unit 12 Transmission 2 Supply Unit 21 Feeding Roller 22 Swing Arm 23 Pressing Member 24 Pressing Roll 25 Actuator 26 Holder 27 First Feeding Guide 28 Second Feeding Guide 29 Third Feeding Guide 3 First Feeding Member 31 First Driven Roll 32 Conveyor Belt 4 Second Feeding Member 40 Shaft 41 First Calendar Roll 42 Second Calendar Roll / Second Driven Roll 43 First Disk 44 First Guide Body 45 First Guide Surface 46 Second Disk 47 Second Guide Body 48 Second Guide Surface 5 Notch Portion 50 Carriage 51 Notch Member 52 Anvil 53 Damper 54 Notch Driving Portion 6 Delivery Portion 61 Delivery Opening 62 Direction Conversion Member 63 Lever 7 Control Unit 71 Irregularity Sensor 72 Lateral Edge Sensor 73 First Tip Sensor 74 Detection Roller 75 Second Tip Sensor 8 Sheet 81 First Longitudinal Edge 82 Second Longitudinal Edge 9 Continuous Belt-Like Body 101 Alternative Device 111 First Driving Portion 112 Second Driving Portion A Axial Direction B Pivot Axis C Notch Direction C1 First Notch C2 Second Notch C3 Third Notch Cn nth Notch D Pressing Direction E1 Lateral Position E2 Lateral Position F Feeding Direction G Guide Region H Notch Direction I Notch Interval J Detection distance K Cutting line L Detection position M Cutting axis N1 Inlet nip N2 In-and-out nip P Supply path Q Quadrant R1 First roll axis R2 Second roll axis S Square area T Terminal distance V1 First feeding speed V2 Second feeding speed W1 Disk width W2 Guide body width Z Supply plane

Claims

1. An apparatus for converting a sheet of elastomeric material into a continuous strip, the apparatus comprising a cutting section for forming a series of separable cuts in the sheet into a zigzag portion interconnecting the sheets to form the continuous strip, The sheet has two longitudinal edges, and the series of cuts extend alternately from one of the longitudinal edges and terminate at a terminal distance away from the other longitudinal edge, forming a plurality of interconnected zigzag portions, and the cutting section includes a cutting member for cutting the sheet along a cutting line intersecting the supply path, and a lateral edge sensor for detecting the lateral position of the longitudinal edge at a detection position upstream of the cutting line with respect to the supply direction.

2. The apparatus is configured to provide a series of the cuts at a cut interval, and the detection position is upstream of the cutting line at a detection distance equal to or greater than the cut interval from the cutting line, according to the apparatus of claim 1.

3. The lateral edge sensor is arranged to move in a cutting direction parallel to the cutting line together with the cutting member, according to the apparatus of claim 1.

4. The lateral edge sensor is centrally arranged with respect to the cutting member in the cutting direction, according to the apparatus of claim 3.

5. The apparatus further comprises a control unit operatively connected to the lateral edge sensor for receiving a signal indicating an edge position of one of the longitudinal edges at the detection position, and the control unit is configured to associate a signal received from the lateral edge sensor during one of the series of cuts with a future cut to be made in the series of cuts, according to the apparatus of claim 1.

6. The control unit is configured to set the terminal distance of the future cut based on the signal from the lateral edge sensor, according to the apparatus of claim 5.

7. A method for converting a sheet of elastomeric material into a continuous strip using the apparatus of claim 1, The method further comprises the step of detecting the lateral position of the longitudinal edge at a detection position upstream of the cutting line with respect to the supply direction.

8. The series of cuts are provided at a cut interval, and the detection position is upstream of the cut line by a detection distance from the cut line that is equal to or greater than the cut interval, the method according to claim 7. **Claim 9** The method further includes the step of associating a lateral position of a longitudinal edge detected at the detection position during one of the series of cuts with a future cut to be made in the future among the series of cuts, the method according to claim 7. **Claim 10** The method further includes the step of setting an end distance of the future cut based on the lateral position of the longitudinal edge associated with the future cut, the method according to claim 9.

Images