KR102344914B1 - Roller apparatus included in folding system for evenly shaping folded terrace of secondary battery cell - Google Patents

Abstract

According to an embodiment of the present disclosure, a roller apparatus for making the size of a terrace of a pouch-type secondary battery cell uniform includes: a roller configured to press a folded portion of one side of the terrace of the secondary battery cell; a base for supporting the roller; and a conveying device for moving the roller, wherein the roller moves along the longitudinal direction of the secondary battery cell to press the folded portion, and in a partial region of the secondary battery cell, there is a movement path that moves backward with respect to the secondary battery cell in a width direction of the secondary battery cell. Various other embodiments are possible.

Description

Roller device of folding equipment for uniform shape of terrace of folded secondary battery cells

The present disclosure relates to a roller device for making the shape of a terrace of a folded secondary battery cell uniform.

Unless otherwise stated herein, the subject matter described in this section is not prior art to the claims in this application, and should not be admitted as prior art on the grounds that it is recited in this section.

As the use of fossil fuels causes economic and environmental problems, interest in and demand for renewable energy has surged. At the same time, the need for a secondary battery capable of storing renewable energy is also increasing. In particular, lithium secondary batteries have high energy density, long lifespan, and low self-discharge rate, so they are widely used as core parts of portable electronic devices, energy storage systems (ESSs), and electric vehicles. Lithium secondary batteries are mainly used in three types: a prismatic battery, a polymer battery, and a cylindrical battery.

Here, the polymer battery is also called a pouch-type secondary battery because the electrode stack is wrapped with an aluminum thin film (which is usually referred to as a pouch), and the thickness thereof can be reduced and the weight can be reduced, so the usage continues to increase. In such a pouch-type secondary battery, after the electrode laminate is wrapped in a pouch, the edge portion must be sealed, and terraces of a predetermined width may be formed on both sides of the sealed polymer battery. Since the secondary battery battery pack is configured to mount a plurality of pouch-type secondary batteries, a method of reducing the mounting size by folding the terraces on both sides of the pouch-type secondary battery is used for mounting efficiency.

For example, the automatic folding device disclosed in the prior literature (Korean Patent No. 10-1974443, automatic folding device for terrace of secondary battery cells) puts the secondary battery cells on a carrier and transfers the secondary batteries through three steps. It is configured to perform the folding process by sequentially dividing the final angle of the cell terrace to 90 degrees, 180 degrees, and 270 degrees. However, with this simple folding process alone, the folded part of the terrace may be unfolded or part of the folded part may be lifted due to the springback phenomenon. As a result, the shape of the terrace of the secondary battery cell that has been subjected to the conventional automatic folding device is not uniformly maintained, thereby increasing the defect rate and may cause inefficiency in assembling the secondary battery module using the secondary battery cell. Due to such a problem, if a process such as discharging and checking defective products or performing folding again is performed, the folding process takes a lot of time and money.

Registered Patent No. 10-1974443 Terrace automatic folding device for secondary battery cells

The present disclosure has been devised to solve the above problems, and an object of the present disclosure is to provide a roller device for uniformizing the shape of a folded terrace of a secondary battery cell that has completed a folding process in a folding facility.

Specifically, an object of the present disclosure is to provide a roller device capable of maintaining a uniform size and angle of each of the folded terraces of secondary battery cells that have completed the folding process in a folding facility.

In addition, by including the roller device according to the present disclosure in the folding equipment, it is intended that the folding process of the secondary battery cell and the process of matching the size and angle of the terrace can be performed in one folding equipment, not in a separate equipment.

According to an embodiment of the present disclosure, a roller device for uniform size of a terrace of a pouch-type secondary battery cell includes: a reference roller for pressing a folded portion of one side of the terrace of the secondary battery cell to be positioned; a forming roller for pressing the folding part of the terrace of the secondary battery cell to have a predetermined angle; And it may include a conveying device to be pressed in turn by the reference roller and the reference roller in the folded order of one side of the terrace of the secondary battery cell.

According to an embodiment of the present disclosure, in the roller device, when the folded portion of one side of the terrace of the secondary battery cell is pressed by the reference roller and the forming roller, the one side of the terrace of the secondary battery cell is not folded It may further include a support block in contact with the bottom surface.

According to an embodiment of the present disclosure, the reference roller has an inclined surface inclined at a predetermined angle and a protrusion protruding from the inclined surface, and between the inclined surface and the protrusion, one side of the terrace of the secondary battery cell is folded. The upper end of the part is positioned so that the folded part of one side of the terrace of the secondary battery cell can be positioned.

According to an embodiment of the present disclosure, the roller device further includes a cell fixing device for fixing the secondary battery cell, and the transfer device includes the reference roller and the secondary battery cell fixed by the cell fixing device. Forming rollers can be transported.

According to an embodiment of the present disclosure, the cell fixing device may further include a support block in contact with an unfolded bottom surface of one side of the terrace of the secondary battery cell.

According to an embodiment of the present disclosure, the roller device further includes a roller fixing device for the reference roller and the forming roller, and the conveying device is secondary to the reference roller and the forming roller fixed by the roller fixing device. Battery cells can be transported.

The above brief summary and description of effects are merely exemplary and are not intended to limit the technical matters intended in the present disclosure. In addition to the above-described exemplary embodiments and technical features, additional embodiments and technical features may be understood by referring to the following detailed description and accompanying drawings.

The features of the present disclosure described above and other additional features will be described in detail below with reference to the accompanying drawings. These drawings illustrate only a few embodiments according to the present disclosure, and should not be construed as limiting the scope of the technical spirit of the present disclosure. The technical spirit of the present disclosure will be described more specifically and in detail using the accompanying drawings.
1 is a perspective view illustrating an example of a secondary battery cell before being folded by a folding device according to an embodiment of the present disclosure.
2 is a perspective view illustrating an example of a secondary battery cell after being folded in a folding facility according to an embodiment of the present disclosure.
3 is a perspective view of a roller device for uniformizing a shape of a folded terrace of a secondary battery cell according to an embodiment of the present disclosure;
4 is a cross-sectional view taken along a cross-section A-A' of FIG. 3 .
4 is a cross-sectional view taken along a cross-section A-A' of FIG. 3 .

Terms used in the present disclosure are used only to describe specific embodiments, and may not be intended to limit the scope of other embodiments. The singular expression may include the plural expression unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meanings as commonly understood by one of ordinary skill in the art described in the present disclosure. Among the terms used in the present disclosure, terms defined in a general dictionary may be interpreted with the same or similar meaning as the meaning in the context of the related art, and unless explicitly defined in the present disclosure, ideal or excessively formal meanings is not interpreted as In some cases, even terms defined in the present disclosure cannot be construed to exclude embodiments of the present disclosure.

The features of the present disclosure described above and other additional features will be described in detail below with reference to the accompanying drawings. These drawings illustrate only a few embodiments according to the present disclosure, and should not be construed as limiting the scope of the technical spirit of the present disclosure. The technical spirit of the present disclosure will be described more specifically and in detail using the accompanying drawings.

1 is a perspective view illustrating an example of a secondary battery cell before being folded by a folding device according to an embodiment of the present disclosure. 2 is a perspective view illustrating an example of a secondary battery cell after being folded in a folding facility according to an embodiment of the present disclosure. A secondary battery cell before folding and a secondary battery cell after folding will be described with reference to FIGS. 1 and 2 .

First, referring to FIG. 1 , the secondary battery cell 100 includes an electrode assembly 110 and a pouch case 120 .

The electrode assembly 110 may be a stack type (stacked type) electrode assembly in which a plurality of positive and negative electrode plates cut in units of a predetermined size are sequentially stacked with a separator interposed therebetween. The positive lead 111 and the negative lead 112 of the electrode assembly 110 may face each other and be exposed at both sides of the pouch case 120 . In the secondary battery cell 100 of another embodiment, the positive lead 111 and the negative lead 112 of the electrode assembly 110 may be exposed from the same side.

The pouch case 120 may be configured to accommodate the electrode assembly 110 and the electrolyte and seal the periphery. The periphery of the pouch case 120 may be referred to as a sealing portion, and the sealing portions on both sides of the pouch case 120 on which the positive lead 111 and the negative lead 112 are not disposed may be referred to as a terrace 121 . have. The terrace 121 of the secondary battery cell 100 before folding may be manufactured by cutting the pouch casing 120 to accommodate the electrode assembly 110 and the electrolyte, sealing the perimeter, and then cutting to a predetermined size.

As the terrace 121 of the secondary battery cell 100 undergoes a folding process in the folding facility according to an embodiment of the present disclosure, the edge of the terrace 121 may be cut along the cutting line 122 , It may be folded by 180 degrees along the first folding line 123 , and may be folded by 90 degrees along the second folding line 124 . Referring to FIG. 2 , the secondary battery cell 100 on which the folding process according to an embodiment of the present disclosure has been performed can be identified.

As the secondary battery cell 100 undergoes a folding process by the folding facility according to an embodiment, it may have a width smaller by a predetermined length D than before folding. That is, when the secondary battery cell 100 passes through the folding facility according to an embodiment of the present disclosure, the terrace 121 of the pouch exterior material 120 is folded, thereby reducing the size of the secondary battery cell 100 to reduce the size of the secondary battery battery pack. It is possible to improve the space efficiency when mounted on the

However, in the folded terrace 125 of the secondary battery cell 100 that has undergone the folding process, the folding angle is greater than the intended angle due to the springback phenomenon, or the folding degree of the secondary battery cell 330 is arbitrary along the longitudinal direction. may be different at each point of Accordingly, each of the folded terraces of the plurality of secondary battery cells may have a different shape and may not have a required shape. A plurality of secondary battery cells 100 in which the terrace 125 is folded are accommodated in the battery pack. If the shape of the folded terrace 125 is not uniform, it may not be accommodated in the battery pack or may be damaged in the storage process. Failure of the battery cell 100 or the entire battery pack may be caused.

3 illustrates a roller device for uniformizing a shape of a folded terrace of a secondary battery cell according to an embodiment of the present disclosure. According to an embodiment of the present disclosure, the secondary battery cell 330 that has undergone the folding process may then be moved to the roller device 300 to additionally undergo a shape equalization process. That is, the roller device 300 according to an embodiment of the present disclosure prevents a spring-back phenomenon of the folded terrace that may occur after the folding process to maintain the folding angle at a desired angle. In addition, the roller device 300 is performed immediately after the folding process of the secondary battery cell 330 is finished, so that all processes can be performed through one folding facility, so the time required for folding the terrace of the secondary battery cell and cost can be reduced, and production efficiency can be maximized.

Referring to FIG. 3 , the roller device 300 according to an embodiment of the present disclosure may include a roller part 310 and a support part 320 . The roller device 300 according to an embodiment of the present disclosure may perform a process of uniformizing the size and folding angle, that is, the shape of the folded terrace 331 of the secondary battery cell 330 as the last process of the folding facility. have.

According to an embodiment, the roller unit 310 may include a reference roller 311 , a first forming roller 312 , and a second forming roller 313 . The roller unit 310 may be positioned so that the rotating roller surfaces of the rollers 311 , 312 , 313 included in the roller unit 310 press a part of the folded terrace 331 of the secondary battery cell 330 . have. The roller unit 310 is transferred in the longitudinal direction (arrow) of the secondary battery cell 330 , and the reference roller 311 first presses the folded terrace 331 of the secondary battery cell 330 , and sequentially The first forming roller 312 and the second forming roller 313 may be transferred to press the folded terrace 331 . As the roller unit 310 is transferred in the longitudinal direction of the secondary battery cell 330 , the rollers 311 , 312 , 313 included in the roller unit 310 press the folded terrace 331 to the folded terrace ( 331) may be molded to have a uniform shape. In FIG. 3 , the roller unit 310 is illustrated as including one reference roller 311 and two forming rollers 312 , 313 , but according to an embodiment, the roller unit 310 includes a variable number of reference rollers and forming rollers. may include

According to an embodiment, the roller unit 310 may be moved with respect to the secondary battery cell 330 along various paths. For example, the roller unit 310 may move in a straight path along the longitudinal direction (arrow) of the secondary battery cell 330 . As the roller part 310 moves with respect to the secondary battery cell 330 , the reference roller 311 places the folded terrace 331 of the secondary battery cell 330 in a position as a reference, and the reference roller 311 . The folded terrace 331 positioned in place by the forming roller 312 has a folded shape along the longitudinal direction of the secondary battery cell 330 . That is, the reference roller 311 is a pre-processing process before the folded terrace 331 is formed by the forming roller 312, and the folded terrace 331 can be placed in the correct position, and the forming roller 312 is folded. By pressing the terrace 331, the effect of uniforming the shape may be increased. A process in which the reference roller 311 and the forming roller 312 act on the folded terrace 331 of the secondary battery cell 330 will be described in detail later.

According to an embodiment, the reference roller 311 and the forming rollers 312 and 313 of the roller unit 310 may be configured to freely rotate about their respective rotation axes, and thus the roller unit 310 for the secondary battery cell 330 . ) can rotate at a speed adaptive to the moving speed of That is, the rollers of the roller unit 310 are configured to rotate freely, so that the moving speed of the roller unit 310 with respect to the secondary battery cell 330 can be freely adjusted. According to an embodiment, at least one pair of rollers among the reference roller 311 and the forming rollers 312 and 313 of the roller unit 310 may be configured to rotate at the same speed. For example, adjacent rollers, such as first forming roller 312 and second forming roller 313 may be connected via belt 314 and configured to rotate simultaneously. As described above, as the rollers are configured to rotate at the same time, it is possible to prevent damage due to rubbing of the folded terrace 331 of the secondary battery cell 330 that occurs when each roller rotates at a different speed. Although an example in which only the first forming roller 312 and the second forming roller 313 are connected is illustrated in FIG. 3 , the rollers may be connected in various combinations.

According to one embodiment, when the rollers of the roller part 310 act on the folded terrace 331 of the secondary battery cell 330 , a part (or support block) of the support part 320 is the secondary battery cell 330 . The folded terrace 331 and the electrode assembly (eg, reference numeral 110 in FIG. 1 ) may be configured to be in contact with the non-folded bottom surface of the terrace positioned between the mounted part (or the main room). In other words, when the secondary battery cell 330 is pressed by the roller part 310 of the roller device 300 , the support part 320 comes into contact with the non-folded bottom surface of the secondary battery cell 330 on the terrace of the secondary battery cell. It is possible to provide a drag force (vertical or horizontal drag) against the force applied by the roller of the roller portion 310 of the 330 . According to one embodiment, the support part 320 has a support block 321 in direct contact with the bottom surface 333 of the secondary battery cell 330 and a portion 332 (or main room) on which the electrode assembly is mounted. It may include a base member 322 defining a space.

According to an embodiment, the roller device 300 may include a conveying device and a cell fixing device. The roller unit 310 by the transfer device may be transferred in the longitudinal direction with respect to the secondary battery cell 330 fixed by the cell fixing device. In another embodiment, the roller part 310 is fixed, and the transport device transports the secondary battery cell 330 in the longitudinal direction so that the roller part 310 presses the folded terrace 331 of the secondary battery cell 330 . can do it In one embodiment, the cell fixing device brings the secondary battery cells 330 to the cell fixing device for the process of the roller device 300, and after the process is finished, the secondary battery cells 330 from the cell fixing device for another process. ) may include a cell transfer device that takes The cell transport device may be a robot arm, a conveyor belt, or an elevating transport device method. The cell fixing device may be applied to a press method, an adsorption method, or the like.

In FIG. 3 , the folding device 300 is shown to process only the terrace of one side of the secondary battery cell 330 as a single device, but in an embodiment, the folding device 300 is composed of a pair of devices At the same time as performing the equalization process for making the shape of the folded terrace of one side of the battery cell uniform, the equalization process may also be performed on the folded terrace of the opposite side of the one side.

4 is a cross-sectional view taken along a cross-section A-A' of FIG. 3 . Referring to FIG. 4 , the principle that the reference roller 311 of the roller device 300 according to an embodiment of the present disclosure acts on the secondary battery cell 330 can be confirmed.

According to an embodiment, the reference roller 311 of the roller device 300 may include an inclined surface 411 inclined at a predetermined angle and a protrusion 412 protruding from the inclined surface 411 . The angle of the inclined surface 411 may be inclined to have a smaller radius than the protruding jaw 412 at a portion where it meets the protruding jaw 412 . The inclined surface 411 may have an arbitrary angle, and the angle may be 80 degrees to 60 degrees.

According to an embodiment, when the reference roller 311 acts on the secondary battery cell 330 , the secondary battery cell 330 is folded between the inclined surface 411 of the reference roller 311 and the protrusion 412 . One end of the finished terrace 331 may be located. Specifically, the upper end of the folded terrace 331 of the secondary battery cell 330 may be located between the inclined surface 411 of the reference roller 311 and the protrusion 412 . The space between the inclined surface 411 of the reference roller 311 and the protrusion 412 may place the folded portion 331 of the terrace, which does not have a uniform shape during the folding process, in place. In other words, the space between the inclined surface 411 of the reference roller 311 and the protrusion 412 guides the upper end of the folded portion 331 of the terrace, which does not have a uniform shape during the folding process, to the correct position. can do.

According to one embodiment, when the reference roller 311 of the roller part 310 acts on the folded terrace 331 of the secondary battery cell 330 , the support part 320 may be folded of the secondary battery cell 330 . It may have a configuration in contact with the non-folded bottom surface 333 of the terrace positioned between the terrace 331 and the portion 332 (or the main room) on which the electrode assembly is mounted. According to one embodiment, the space between the inclined surface 411 of the reference roller 311 and the protrusion 412 presses the upper end of the folded portion 331 of the terrace that does not have a uniform shape during the folding process. In doing so, the non-folded bottom surface 333 of the support member 321 terrace of the support part 320 may be supported. If the support 320 does not support the bottom surface 333 of the terrace of the secondary battery cell 330 , the force pressing the upper end of the folded portion 321 of the reference roller 311 is the folded portion of the terrace. This is because, rather than correcting the shape of 321 , a problem may arise in that the portion where the terrace of the secondary battery cell 330 starts is bent or provides a folded terrace in a non-uniform shape.

FIG. 5 is a cross-sectional view taken along a cross-section B-B' of FIG. 3 . Referring to FIG. 5 , in the support part 320 of the roller device 300 according to an embodiment of the present disclosure, the forming roller 312 of the roller part 310 is a folded terrace 331 of the secondary battery cell 330 . When acting on the secondary battery cell 330, the folded terrace 331 and the electrode assembly mounted portion 332 (or the main room) located between the non-folded bottom surface 333 of the terrace is in contact with the configuration can

According to an embodiment, the forming roller 312 of the roller device 300 may have an inclined surface 511 inclined at a predetermined angle. The folded portion 331 of the terrace of the secondary battery cell 330 may be pressed at a predetermined angle a2 by the angle a1 of the inclined surface 511 . The predetermined angle a2 may mean a final folding angle of the folded portion 331 of the terrace of the secondary battery cell 330, and a folded angle more than the final folding angle in consideration of the springback phenomenon in advance. may mean

According to one embodiment, when the forming roller 312 presses the upper end of the folded portion 331 of the terrace, the support member 321 of the support portion 320 will support the non-folded bottom surface 333 of the terrace. can If the support 320 does not support the bottom surface 333 of the terrace of the secondary battery cell 330 , the force pressing the upper end of the folded portion 321 of the reference roller 311 is the folded portion of the terrace. This is because, rather than correcting the shape of 321 , a problem may arise in that the portion where the terrace of the secondary battery cell 330 starts is bent or provides a folded terrace in a non-uniform shape.

In one embodiment, in the process of correcting the angle of the terrace 331 in which the forming roller 312 is folded, the roller device is used to further maximize the effect and prevent problems such as occurrence of defective products that deviate from the prescribed angle. In 300, the forming roller 312 may be configured in plurality. For example, the roller device 300 may further include a second shaping roller (eg, reference numeral 313 in FIG. 3 ) in addition to the first shaping roller (eg, reference numeral 312 in FIG. 3 ). The folded terrace 331 may be pressed by a plurality of forming rollers to further improve the straightening effect. The plurality of forming rollers press the folded terrace 331 for a longer period of time than when one forming roller presses the folded terrace 331, thereby completely removing the internal stress that causes the springback phenomenon, and thus the folded terrace can improve the uniformity of the shape of

In one embodiment, the plurality of forming rollers (eg, reference numerals 312 and 313 in FIG. 3 ) may be configured to have different angles with respect to the inclined surface of the folded terrace 331 . For example, each of the plurality of forming rollers may be configured at an angle having a small inclination sequentially from the direction in which the secondary battery cell 330 enters to the direction in which the secondary battery cell 330 advances. For example, it is assumed that the folding angle of the folded terrace 331 of the secondary battery cell 330 to be finally produced is 72 degrees. In this case, the angle of the forming roller (eg, the second forming roller 313) that last acts with respect to the folded terrace 331 of the secondary battery cell 330 is set to 72 degrees, and the former forming roller is 72 degrees It can be set to any large angle. In another example, when there are three or more forming rollers, the inclined surface of each forming roller may be set to have an inclination of 73 degrees, 72.5 degrees, and 72 degrees and sequentially decrease. As described above, by sequentially setting the angles of the inclined surfaces of the plurality of forming rollers to be small, it is possible to gradually apply a large pressure to the folded terrace 331 of the secondary battery cell 330, and may occur as the pressure is applied at a large angle at once. It is possible to prevent the springback phenomenon caused by the repulsive force. Although FIG. 3 illustrates that there are two forming rollers (the first forming roller 312 and the second forming roller 313), the forming roller may be configured in a number greater than two. Also, in one embodiment, the forming roller as well as the reference roller may consist of more than one number.

The foregoing detailed description has set forth various embodiments of apparatus and/or processes through the use of block diagrams and/or examples. To the extent such block diagrams and/or examples include one or more functions and/or operations, those skilled in the art will recognize that each function and/or operation within such block diagrams or examples may represent hardware, software, firmware, or substantially any combination thereof. It will be understood that the broad scope of the invention may be implemented individually and/or collectively.

While specific exemplary techniques have been described and illustrated herein using various methods and systems, those skilled in the art will understand the possibility of various other modifications or equivalents permutations without departing from the claimed subject matter. Additionally, many modifications may be made to adapt a particular situation to the teachings of the claimed subject matter without departing from the central concepts described herein. Accordingly, it is intended that claimed subject matter not be limited to the specific examples disclosed, but that such claimed subject matter may also include all embodiments falling within the scope of the appended claims and their equivalents.

Throughout the present disclosure, when a part is "connected" with another part, this includes not only the case of being "directly connected", but also the case of being "mechanically connected" with another element interposed therebetween. do. In addition, throughout the present disclosure, when a member is said to be located "on" another member, this includes not only a case in which a member is in contact with another member but also a case in which another member is present between the two members. Furthermore, throughout the present disclosure, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated. As used herein, the terms "about," "substantially," and the like, are used in a sense at or close to the numerical value when the manufacturing and material tolerances inherent in the stated meaning are presented, and to aid in the understanding of the present application. It is used to prevent an unconscionable infringer from using the mentioned disclosure in an unreasonable way.

The scope of the present disclosure is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims, and their equivalent concepts are interpreted as being included in the scope of the present application. should be

Claims (6)

In the roller device for making the size of the terrace of the pouch-type secondary battery cell uniform,
a reference roller for pressing the folded portion of one side of the terrace of the secondary battery cell to be in the correct position;
a forming roller for pressing the folding part of the terrace of the secondary battery cell to have a predetermined angle; and
and a conveying device for sequentially pressing a portion of one side of the terrace of the secondary battery cell by the reference roller and the forming roller,
The reference roller has an inclined surface inclined at a certain angle and a protrusion protruding from the inclined surface, and the upper end of the folded portion of one side of the terrace of the secondary battery cell is positioned between the inclined surface and the protruding protrusion. The folded portion of one side of the terrace of the battery cell is to be positioned, the roller device. The method of claim 1,
When the folded portion of one side of the terrace of the secondary battery cell is pressed by the reference roller and the forming roller, the secondary battery cell further comprises a support block in contact with the non-folded bottom surface of the one side of the terrace.
roller device. delete The method of claim 1,
Further comprising a cell fixing device for fixing the secondary battery cell,
The transport device is to transport the reference roller and the forming roller with respect to the secondary battery cell fixed by the cell fixing device, the roller device. 5. The method of claim 4,
The cell fixing device will further include a support block in contact with an unfolded bottom surface of one side of the terrace of the secondary battery cell, the roller device. The method of claim 1,
Further comprising a roller fixing device for the reference roller and the forming roller,
The transport device is to transport the secondary battery cells with respect to the reference roller and the forming roller fixed by the roller fixing device, the roller device.

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