Plate tensioning shaft

Abstract

Invention details;

Description

Sheet winding shaft

[0001] The present invention relates to a sheet take-up shaft for taking up a sheet.

[0002] Sheet winding shafts are used to wind up sheets of paper, film, or the like that have been slit into narrow widths. For example, a winding shaft called a friction winding shaft is known. A friction winding shaft has a structure in which multiple winding sections are fitted onto a base shaft, allowing them to rotate relative to one another, and the rotation of the base shaft is transmitted to the winding sections via a rotation torque adjustment member. A winding core (e.g., a paper tube) is fixed to the winding sections, and the slit sheet is wound around the core fixed to the winding sections.

[0003] If the structure for transmitting the rotational torque to the winding section as described above is not provided, and multiple winding cores are fixed to a base shaft and rotated in the same direction to wind the sheet, tension will be concentrated on the wound product, which has a slightly larger outer diameter due to unevenness in the thickness of the sheet, resulting in large differences in the winding tension for each wound product and causing poor winding of the wound product.

[0004] In contrast, the friction winding shaft can transmit the same rotational torque to wound products with slightly different outer diameters caused by uneven sheet thickness, etc., and can prevent tension from concentrating on wound products with slightly larger outer diameters. Also, by controlling the air pressure flowing into the rotational torque adjustment member, a rotational torque corresponding to the winding diameter of the wound product can be applied to the winding core, and as a result, optimal winding tension corresponding to the outer diameter can be applied to the sheet.

[0005] In this friction winding shaft, the winding core is fixed to the winding section, and there are several methods for doing so. For example, in Patent Document 1, a locking claw is placed on the inclined portion of a sliding ring inside the winding section, and the position of the sliding ring is operated with a piston, allowing the locking claw to protrude and retract from the winding section, thereby fixing and releasing the winding core. This piston can be protruded by a spring attached to the sliding ring or by the inflow of compressed air from the winding rotation shaft member. In this winding shaft, the locking claw is normally protruded, and when the winding core is removed, compressed air is introduced to retract the locking claw.

[0006] In Patent Document 2, a roller is placed in a recessed portion provided on the outer peripheral surface of the collar, and the roller switches between protruding and retracting from an opening in a cover ring depending on whether the roller is in the shallow or deep portion of the recess, thereby fixing or releasing the winding core. With this winding shaft, by rotating the cover ring in the direction opposite to the winding rotation relative to the friction ring (collar), the roller protrudes from the opening and the winding core is fixed, and by rotating the cover ring in the direction of the winding rotation relative to the friction ring, the roller retracts and the fixation of the winding core is released.

[0007] JP2005-15170A JP11-208942A

[0008] In the winding shaft described in Patent Document 1, a locking claw, which is part of the winding section, locks the winding core, so that the rotational torque of the winding section is transmitted to the winding core. If the number of winding sections corresponding to each winding core differs for each winding core, this will cause differences in rotational torque for each winding core. If any locking claw can be set to a recessed state, the number of locking claws of the winding section corresponding to each winding core can be easily adjusted. Furthermore, if any part of the locking claw is in slight contact with the winding core, part of the winding core will be scraped off, which could lead to the introduction of foreign matter. For these reasons, it is preferable to maintain any locking claw of each winding section in a recessed state for friction winding shafts, not just the winding shaft described in Patent Document 1.

[0009] In this regard, with the structure described in Patent Document 1, when compressed air flows in, the locking claws of all winding sections are in a recessed state, and when the flowing in compressed air is released, the locking claws of all winding sections are in a protruding state. With the winding shaft described in Patent Document 1, for example, if the position of the slide ring of an arbitrarily selected winding section can be operated so as to be fixed in the position when compressed air flows in, it is possible to maintain the locking claw of only the winding section that has been arbitrarily fixed in a recessed state.

[0010] On the other hand, the winding shaft described in Patent Document 1 has the advantages that when the locking claws lock onto the winding core, there are no restrictions on the direction of rotation and the winding core is securely locked even at low torque. However, it has a large number of parts and a complex structure, which makes assembly and maintenance cumbersome and is disadvantageous in terms of durability and cost, so there has been a demand for a simpler structure.

[0011] In contrast, the winding shaft described in Patent Document 2 has a simpler structure than the winding shaft described in Patent Document 1 and can be manufactured inexpensively. However, the winding shaft described in Patent Document 2 has a structure in which the roller bites into the gap between the winding core and the shallow portion of the recessed portion, thereby locking the winding core to the collar. With this structure, the winding core will not be locked unless the roller sufficiently protrudes from the cover ring. If the diameter of the roller is increased to obtain a sufficient amount of protrusion, the diameter of the shaft on which the winding portion is fitted must be reduced because the diameter of the winding shaft is fixed, making it difficult to maintain the strength of this shaft.

[0012] One way to obtain a sufficient protrusion amount is to thin the cover ring. However, the cover ring has an opening at the top of the gap that is large enough to allow part of the roller to protrude in order to prevent the roller from falling off. If the cover ring is thinned and the opening is widened to a size close to the outer shape of the roller, the roller will get locked in the opening. The winding shaft of Patent Document 2 had to be designed taking these balances into consideration, which led to design constraints.

[0013] Furthermore, the winding spindle of Patent Document 2 is also required to maintain a submerged state for the roller of an arbitrarily selected winding section. For example, for an arbitrarily selected covering, if the collar and covering can be fixed while the roller is in the deep part of the recessed portion, it is thought that the roller can be maintained in a submerged state. However, simply fixing the collar and covering creates a problem in that when winding is performed at high speed, the centrifugal force generated by the rotation of the winding spindle causes the roller to protrude and interfere with the winding core.

[0014] The present invention solves the above-mentioned problems and aims to provide a sheet winding shaft that has a structure that is easy to assemble and maintain, and in which the protrusion and retraction of a gripping device for fixing the winding core can be selected as desired for each winding section.

[0015] In order to achieve the above object, the sheet winding shaft of the present invention is a sheet winding shaft that winds a sheet onto a core, and comprises: a base shaft; a plurality of winding sections that are arranged side by side and fitted onto the base shaft; and a rotational torque adjustment means that adjusts the rotational torque between the winding sections and the base shaft, wherein the winding sections comprise: a friction ring having a plurality of inclined sections that rise and fall along the circumferential direction of the shaft on its outer periphery; an exterior collar that fits the friction ring; a gripping device that is fitted into an opening provided in the exterior collar, moves along the inclined sections, and grips the core by protruding outside the exterior collar when it is at the raised section of the inclined sections; and rotation prevention means that can limit the relative rotation of the friction ring and the exterior collar, wherein the gripping device comprises an abutment section that abuts against the inner periphery of the core, and a hook section that engages with the friction ring when it is at the sunken section of the inclined sections.

[0016] This configuration requires fewer parts than a winding spindle that uses compressed air to secure and release the winding core, making assembly and maintenance easier. Furthermore, when multiple winding cores are attached to a sheet winding spindle with multiple winding sections, the exterior collar can be rotated for a selected specific winding section so that the gripping device is positioned at the lowered portion of the inclined portion of the friction ring, allowing the friction ring to engage with the hook of the gripping device. In addition, the rotation prevention device limits the relative rotation between the exterior collar and the friction ring, so that the gripping device remains embedded in the selected specific winding section, and the friction ring remains engaged with the hook of the gripping device. Therefore, even when the winding section is rotated at high speed, centrifugal force can prevent the gripping device from protruding from the outer surface of the exterior collar. In other words, when multiple winding cores are attached to a sheet winding spindle, by embedding the abutting portions for specific winding sections, the number of abutting portions that abut on each winding core can be made uniform, thereby making the winding rotation torque for each core more uniform.

[0017] In the sheet winding shaft of the present invention, it is preferable that the gripping device has a magnetic body at a portion that abuts against the inclined portion of the friction ring. With this configuration, the magnetic body allows the gripping device to slide along the inclined portion, and when the gripping device is located in the submerged portion, the gripping device is in a submerged state, and the hook portion of the gripping device can be guided so as to hook at a predetermined position on the friction ring.

[0018] It is also preferable that the exterior collar is provided with a plunger that contacts the inner periphery of the winding core. With this configuration, the plunger contacts the inner periphery of the winding core, so that when the winding core is manually rotated, the exterior collar rotates along with it, making it easy to rotate the exterior collar. In addition, by locating a portion of the plunger in a groove formed in the friction ring, the plunger can also be used as a fastener that keeps the friction ring and exterior collar in the appropriate positions.

[0019]

[0013] Preferably, an engaging protrusion is formed on the outer peripheral surface of the friction ring, with one end of the engaging protrusion having a protrusion that engages with the hook of the gripping tool and the other end having an abutment surface against which the rotation prevention means abuts. This configuration allows for simple operation to limit the rotation of the exterior collar on the friction ring, making it easy to fasten the gripping tool to the sunken portion of the inclined portion. In addition, when the gripping tool is extended a certain amount, the abutment surface of the engaging protrusion abuts on the gripping tool, limiting the protrusion of the gripping tool. This also reliably prevents the gripping tool from locking when the gripping tool is pinched between the friction ring and the exterior collar by the protrusion (barb) of the gripping tool when extended too far.

[0020] Furthermore, it is preferable that the friction ring has a narrow groove extending in the axial direction, and that the relative rotation between the friction ring and the exterior collar is restricted by engagement of the narrow groove with the rotation prevention means. This configuration also allows the rotation of the exterior collar on the friction ring to be restricted with a simple operation, making it easy to fasten the gripping tool to the sunken portion of the inclined portion. With this configuration, it is not necessary to form an engaging protrusion.

[0021] The advantages of the present invention are as described above. Compared to a winding spindle that uses compressed air to secure and release the winding core, this configuration requires fewer parts, making assembly and maintenance easier. Furthermore, when multiple winding cores are attached to a sheet winding spindle with multiple winding sections, the exterior collar can be rotated for a selected specific winding section so that the gripping device is positioned at the lowered portion of the inclined portion of the friction ring, allowing the friction ring to engage with the hook of the gripping device. In addition, the rotation prevention device can limit the relative rotation between the exterior collar and the friction ring, so that the gripping device remains embedded in the selected specific winding section, and the friction ring remains engaged with the hook of the gripping device. Therefore, even when the winding section is rotated at high speed, centrifugal force can prevent the gripping device from protruding from the outer surface of the exterior collar. In other words, when multiple winding cores are attached to a sheet winding spindle, by embedding the contact portions for specific winding sections, the number of contact portions that contact each winding core can be made uniform, resulting in more uniform winding rotation torque for each core.

[0022] 4 is a schematic diagram showing the appearance of a sheet winding shaft according to a first embodiment of the present invention. FIG. 4 is a perspective view of the appearance of one winding unit shown in FIG. 1. FIG. 4 is a perspective view of the appearance of the winding unit shown in FIG. 2, showing the internal structure. FIG. 4 is a cross-sectional view taken along line AA in FIG. 1. FIG. 4 is a cross-sectional view taken along line DD in FIG. 4. FIG. 4 is a cross-sectional view of a sheet winding shaft in a state in which a gripping device is completely embedded in the shaft according to a first embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line BB in FIG. 2. FIG. 4 is a perspective view showing an engagement state between a friction ring, a gripping device, and a rotation preventing means in the first embodiment of the present invention. FIG. 4 is a perspective view showing a rotation preventing means and its accessories in the first embodiment of the present invention. FIG. 4 is a schematic view showing a process in which the relative rotation between the friction ring and the exterior collar is restricted by operating the rotation preventing means in the first embodiment of the present invention. FIG. 4 is a perspective view showing another example of the rotation preventing means in the first embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line CC in FIG. 2. FIG. 4 is a perspective view showing an engagement state between a friction ring, a gripping device, and a rotation preventing means in the second embodiment of the present invention. FIG. 4 is a cross-sectional view of a sheet winding shaft in a state in which a gripping device is protruding in the shaft according to a second embodiment of the present invention. 14 is a cross-sectional view of a sheet winding shaft in a state where the gripping device is completely buried in the sheet winding shaft in the second embodiment of the present invention. 15 is a cross-sectional view of the vicinity of the rotation prevention means in the second embodiment of the present invention. 16 is a schematic view showing a state where the gripping device is protruded until the gripping device and the abutment surface of the engaging protrusion abut on each other in the vicinity of the gripping device in FIG. 14.

[0023] A sheet winding shaft according to one embodiment of the present invention will be described below with reference to the drawings. The embodiments are broadly divided into a first embodiment and a second embodiment. First, the first embodiment will be described, followed by the second embodiment. FIG. 1 is a schematic diagram showing the appearance of a sheet winding shaft 1 according to the first embodiment of the present invention. The sheet winding shaft 1 has a main shaft 2 on which a plurality of winding sections 3 are arranged and fitted. The winding sections 3 and the main shaft 2 are rotatable relative to each other. The sheet winding shaft 1 can be used as a sheet winding shaft for a slitter (not shown). The slitter slits a wide sheet into narrow sheets. The narrow sheet is wound onto a winding core 10 (see FIG. 4), such as a cardboard tube, attached to the sheet winding shaft 1.

[0024] Fig. 2 is an external perspective view of one winding unit 3 shown in Fig. 1. Fig. 3 is an external perspective view showing the internal structure of the winding unit 3 shown in Fig. 2. Fig. 4 is a cross-sectional view taken along line AA in Fig. 1. Fig. 5 is a cross-sectional view taken along line DD in Fig. 4. Figs. 4 and 5 show a state in which the gripping tool 6 is protruded to grip the winding core 10.

[0025] The details of the winding unit 3 will be described later, but an overview will be given with reference to Figures 2 and 3. In Figure 2, the exterior of the winding unit 3 is formed by an exterior collar 5. A gripper 6, a rotation prevention means 7, and a plunger 8 are arranged on the cylindrical surface of the exterior collar 5. Bearings 9 fixed to the base shaft 2 (see Figure 5) are arranged on both ends of the exterior collar 5. A friction ring 4 that is rotatable relative to the exterior collar 5 is arranged inside the exterior collar 5.

[0026] Figure 3 shows the winding unit 3 shown in Figure 2 with the bearing 9 and friction ring 4 removed. In Figure 2, the gripping tool 6 is disposed in an opening 51 formed in the exterior collar 5. As shown in Figure 3, the gripping tool 6 is also disposed in the opening 51 on the inner peripheral surface side of the exterior collar 5. This allows the gripping tool 6 to come into contact with the friction ring 4 disposed inside the exterior collar 5, as shown in Figure 8, which will be described later.

[0027] 4, the main components of the winding section 3 are a friction ring 4, an exterior collar 5, and a gripping device 6. The friction ring 4 is fitted inside the exterior collar 5, and the gripping device 6 is embedded in the exterior collar 5. As shown in FIG. 5, a bearing 9 is interposed between the winding section 3 and the base shaft 2, allowing the winding section 3 and the base shaft 2 to rotate relative to each other.

[0028] 4 and 5 , a fluid path 21 for circulating a compressed fluid is formed within the main shaft 2. A connection hole 22 branches off midway through the fluid path 21, and a rotational torque adjustment means 23 composed of a piston is provided within the connection hole 22. When compressed fluid is circulated within the main shaft 2, the rotational torque adjustment means 23 is pressed in a direction in which it protrudes outward from the main shaft 2. This pressing causes the top of the rotational torque adjustment means 23 to come into contact with the inner periphery of the friction ring 4 of the winding unit 3 that is fitted onto the main shaft 2, generating friction. This friction transmits the rotational torque of the main shaft 2 to the winding unit 3, and the sheet can be wound onto the winding core 10 attached to the winding unit 3 while adjusting the rotational torque between the winding unit 3 and the main shaft 2.

[0029] As shown in Figure 4, the inner periphery of the friction ring 4 is a perfect ring shape so that the rotational torque adjustment means 23 can be uniformly abutted against it, while the outer periphery has multiple undulations. Specifically, the friction ring 4 has a gentle inclined portion 41 whose thickness gradually decreases along its circumferential direction. In this case, one end of the inclined portion 41 is a raised portion 45 and the other end is a sunken portion 46. The friction ring 4 has four inclined portions 41, and the raised portions 45 and sunken portions 46 are alternately formed along the circumferential direction.

[0030] 4, the friction ring 4 has a protrusion 44 at the portion where the thin-walled recessed portion 46 changes to a thick-walled portion. The protrusion 44 is formed so that its tip protrudes in the circumferential direction of the axis of the friction ring 4. As will be described in detail later, the protrusion 44 is intended to engage with a hook portion 62 of the gripping tool 6.

[0031] In FIG. 4 , the exterior collar 5 is annular and is attached to the base shaft 2 via a bearing 9 (see FIG. 5 ). The friction ring 4 is fitted inside the exterior collar 5 so as to be rotatable relative to the friction ring 4. As shown in FIGS. 4 and 5 , the exterior collar 5 has an opening 51 for allowing the gripping tool 6 to protrude, and the gripping tool 6 is fitted into the opening 51 so that one end of the gripping tool 6 protrudes from the opening 51. As shown in FIG. 5 , the gripping tool 6 may be provided with a protrusion 61 (barb) to prevent it from falling off (detaching). The protrusion 61 may be provided so as to protrude a portion of the outer periphery of the gripping tool 6. The shape of the opening 51 is arbitrary and may be determined appropriately taking into consideration the shape of the portion from which the gripping tool 6 protrudes and the size of the protrusion 61 provided on the gripping tool 6.

[0032] As shown in Figures 4 and 5, a contact portion 63 formed on one end of the gripping tool 6 protrudes from the opening 51. The contact portion 63 is a portion that contacts the inner periphery of the winding core 10, and as shown in Figures 1 to 3, it has a rounded rectangular shape with four chamfered corners in plan view. Also, as shown in Figures 4 and 5, the contact portion 63 is formed with claws to improve the gripping force with the winding core 10. The shape of the contact portion 63 may be appropriately determined to be optimal depending on the material of the winding core 10. The presence or absence of claws is optional, and instead of being limited to claws, unevenness such as horizontal stripes, vertical stripes, diamonds, or lattices may be formed, or an elastic material may be disposed.

[0033] 4, the gripping tool 6 is disposed at a position corresponding to the inclined portion 41 of the friction ring 4, and the bottom surface that abuts against the inclined portion 41 forms a curved surface. This keeps the contact area between the gripping tool 6 and the inclined portion 41 small, allowing the gripping tool 6 to move smoothly on the inclined portion 41.

[0034] 3 and 5, a magnetic body 64 (permanent magnet) is disposed on the gripping tool 6 at a portion thereof that abuts against the inclined portion 41 of the friction ring 4 (the bottom side of the gripping tool 6). The magnetic body 64 is for moving the gripping tool 6 along the inclined portion 41. Instead of the magnetic body 64, the gripping tool 6 may be held down by a ring spring, a rubber ring, or the like, but a ring spring or the like would need to be housed in the exterior collar 5 or the gripping tool 6, which would complicate the structures of the exterior collar 5 and the gripping tool 6. The magnetic body 64 allows the gripping tool 6 to slide and move easily along the inclined portion 41, and therefore makes it easier to guide the gripping tool 6 against the protrusion 44, which will be described later.

[0035] 4, the gripping tool 6 is located on the raised portion 45 of the friction ring 4, and the abutting portion 63 protrudes from the outer peripheral surface of the exterior collar 5. When the abutting portion 63 is in this protruding state, the winding core 10 attached to the winding unit 3 is fixed.

[0036] 4, the friction ring 4 and the exterior collar 5 are rotatable relative to each other, and when the exterior collar 5 is rotated relative to the friction ring 4, the gripping tool 6 moves along the inclined portion 41 while maintaining contact with the friction ring 4 due to the magnetic force of the magnetic body 64. As this movement progresses, the gripping tool 6 approaches the sunken portion 46 of the inclined portion 41, and the gripping tool 6 sinks further into the opening 51.

[0037] 6 shows a cross-sectional view of the sheet winding shaft 1 in a state where the gripping device 6 is completely buried. In the state shown in FIG. 6, the gripping device 6 is completely buried in the opening 51, and the abutting portion 63 of the gripping device 6 does not protrude from the outer peripheral surface of the exterior collar 5. In this state, the abutting portion 63 moves away from the winding core 10, and the gripping device 6 releases the winding core 10 from its fixation.

[0038] 6, in order to maintain the gripping tool 6 completely embedded in the opening 51 and restrict the movement of the abutting portion 63 of the gripping tool 6 in the direction of protruding from the outer peripheral surface of the exterior collar 5, it is sufficient to restrict the relative rotation between the friction ring 4 and the exterior collar 5. For this reason, in this embodiment, the winding part 3 is provided with a rotation prevention means 7 as shown in FIG.

[0039] The anti-rotation means 7 will be described in detail below with reference to Figures 7 to 9. Figure 7 is a cross-sectional view taken along line BB in Figure 2. Figure 8 is a perspective view showing the engagement between the friction ring 4, the gripper 6, and the anti-rotation means 7. Figure 9 is a perspective view showing the anti-rotation means 7 and its accessories.

[0040] As shown in FIG. 7 , the anti-rotation means 7 is housed in a housing 52 formed in the exterior collar 5 via an attachment body 74, and the protrusion 71 of the anti-rotation means 7 engages with the narrow groove 43 of the friction ring 4. An O-ring 77 for preventing rotation of the anti-rotation means 7 is interposed between the anti-rotation means 7 and the housing 52. As shown in FIG. 8 , the narrow groove 43 extends in the axial direction of the friction ring 4. More specifically, as shown in FIG. 9 , the anti-rotation means 7 has a generally cylindrical body with a protrusion 71 at one end and a flange 72 at the other end. The flange 72 engages with a notch formed in a disk-shaped attachment body 74, and the anti-rotation means 7 is supported by the attachment body 74.

[0041] A hole 75 is formed in the mounting body 74, and a screw 76 passing through the hole 75 is fastened to the exterior collar 5. As a result, as shown in Fig. 2, the anti-rotation means 7 is attached to the exterior collar 5 with the flange 72 exposed to the outside. In Fig. 9, a lateral groove 73 is formed in the flange 72, and in Fig. 2, the anti-rotation means 7 can be rotated by inserting a tool into the lateral groove 73.

[0042] The operation of the rotation prevention means 7 will be described below with reference to Fig. 10. Fig. 10 is a schematic diagram showing the process by which the operation of the rotation prevention means 7 leads to a state in which the relative rotation between the friction ring 4 and the exterior collar 5 is restricted. Fig. 10 corresponds to a view of the friction ring 4 in Fig. 8 as seen from the direction of arrow E. In Fig. 10, the rotation prevention means 7 is illustrated in a simplified manner. In each drawing in Fig. 10, the friction ring 4 is formed with a groove 42 extending in the circumferential direction of the shaft and a narrow groove 43 crossing the friction ring 4 in the axial length direction.

[0043] 10(a) shows a state in which the rotation prevention by the rotation prevention means 7 is released. In this state, the convex portion 71 of the rotation prevention means 7 is inside the groove 42, so the rotation prevention means 7 can move along the groove 42, and the exterior collar 5 with which the rotation prevention means 7 is integrated can also rotate.

[0044] Figure 10(b) shows the state in which the rotation prevention means 7 has been rotated from the state in Figure 10(a). As mentioned above, in Figure 2, the rotation prevention means 7 can be rotated by inserting a tool into the lateral groove 73. Figure 10(c) shows the state in which the rotation prevention means 7 has been further rotated from the state in Figure 10(b). In this state, the protrusion 71 of the rotation prevention means 7 is inside the narrow groove 43. This state corresponds to the state in Figure 7, in which the movement of the protrusion 71 is restricted inside the narrow groove 43, restricting the movement of the rotation prevention means 7 and also restricting the relative rotation of the exterior collar 5, with which the rotation prevention means 7 is integrated, with respect to the friction ring 4.

[0045] The anti-rotation means 7 in this embodiment is an example, and any means capable of restricting relative rotation between the friction ring 4 and the exterior collar 5 may be used. For example, the anti-rotation means 7 may be replaced with a pin or a screw. Figure 11 is a perspective view showing another example of the anti-rotation means. An attachment body 91 is fixed to the exterior collar 5 with a screw 92, and the attachment body 91 is located inside the outer surface of the exterior collar 5. An elongated hole 93 is formed in the attachment body 91, and a pin-shaped anti-rotation means 90 is disposed in the elongated hole 93.

[0046] A recess is formed at the upper end of the rotation prevention means 90, and a tool can be inserted into the recess to move the rotation prevention means 90 along the elongated hole 93. In the state shown in Figure 11, the lower end of the rotation prevention means 90 is located within the narrow groove 43, restricting the movement of the rotation prevention means 90 and also restricting the rotation of the exterior collar 5 to which the rotation prevention means 90 is attached. From this state, by inserting a tool into the recess at the upper end of the rotation prevention means 90 and moving the rotation prevention means 90 along the elongated hole 93, the lower end of the rotation prevention means 90 can be placed within the groove 42, and the rotation prevention state of the exterior collar 5 can be released.

[0047] 6 to 8, when the gripping tool 6 is in the sunken portion 46 of the friction ring 4, the protrusions 44 of the friction ring 4 engage with the hook portions 62 of the gripping tool 6. In this state, movement of the gripping tool 6 in the direction of protruding from the outer surface of the exterior collar 5 is restricted. The hook portions 62 are concave recesses into which the convex protrusions 44 fit. The engagement structure between the gripping tool 6 and the friction ring 4 may be any structure as long as it can restrict protrusion of the gripping tool 6 from the outer surface of the exterior collar 5.

[0048] 7 and 8, the protrusions 44 of the friction ring 4 are engaged with the hook portions 62 of the gripping tool 6, and the convex portions 71 of the rotation prevention means 7 are located within the narrow grooves 43. In this state, the relative rotation between the exterior collar 5 and the friction ring 4 is restricted, so the state in which the protrusions 44 of the friction ring 4 are engaged with the hook portions 62 of the gripping tool 6 is maintained. Therefore, even when the reel unit 3 is rotated at high speed, the gripping tool 6 can be prevented from protruding from the outer surface of the exterior collar 5 due to centrifugal force.

[0049] Next, the plunger 8 (see Figures 1 to 4 and 6) will be described. In Figures 1 to 4 and 6, a portion of the plunger 8 protrudes from the exterior collar 5. Figure 12 is a cross-sectional view taken along line CC in Figure 2. In Figure 12, the plunger 8 includes a spherical body 81, a spring 82, and a cylindrical body 83 that houses these.

[0050] In Figure 12, a sphere 81 protrudes from the outer surface of the exterior collar 5, and a repulsive force of a spring 82 is applied to the sphere 81. When the winding core 10 is attached to the exterior collar 5 in this state, as shown in Figure 6, the sphere 81 sinks toward the cylindrical body 83, and the winding core 10 is pressed by the sphere 81. Therefore, when the winding core 10 is rotated manually, the exterior collar 5 also rotates. The plunger 8 is provided to realize this rotation.

[0051] The plunger 8 in this embodiment is an example, and the plunger 8 is not limited to having the sphere 81 and the spring 82 as long as a member having a repulsive force protrudes from the outer surface of the exterior collar 5 .

[0052] As shown in FIG. 12 , the plunger 8 in this embodiment has a cylindrical body 83 fixed to the exterior collar 5 and disposed in the groove 42 of the friction ring 4. As described above, the relative rotation between the friction ring 4 and the exterior collar 5 can be limited by the anti-rotation means 7. However, since contact between the inner ring of the bearing 9 and the friction ring 4 is suppressed and the anti-rotation means 7 is accurately positioned so that its protrusion 71 can easily engage with the narrow groove 43, it is desirable to limit misalignment between the exterior collar 5 and the friction ring 4 in the axial direction. According to the configuration shown in FIG. 12 , the plunger 8 can move on the friction ring 4 in unison with the rotation of the exterior collar 5, but the cylindrical body 83 in the groove 42 is restricted from moving in a direction across the groove 42, thereby limiting misalignment between the exterior collar 5 and the friction ring 4 in the axial direction. In this embodiment, this limitation is achieved by the cylindrical body 83 of the plunger 8. However, a fastener such as a pin or screw may be inserted from the exterior collar 5 into the groove 42 of the friction ring 4.

[0053] The operation of the sheet winding shaft 1 will now be described. First, the winding core 10 is passed through the winding section 3. Figure 6 corresponds to a cross-sectional view of the sheet winding shaft 1 in this state. When passing the winding core 10 through the winding section 3, the gripping device 6 is placed in a state where it is completely buried in the opening 51, as shown in Figure 6. In Figure 6, if the base shaft 2 is fixed and the rotational torque adjustment means 23 is placed in a state where it presses the friction ring 4, the exterior collar 5 can be rotated counterclockwise (in the direction of arrow b) with the base shaft 2 and friction ring 4 fixed.

[0054] In the state shown in Figure 6, as described above, the plunger 8 presses the winding core 10, so that manually rotating the winding core 10 rotates the exterior collar 5. When the exterior collar 5 is rotated counterclockwise (in the direction of arrow b), the gripping device 6 moves integrally with the winding core 10, and the gripping device 6 reaches the position of the raised portion 45 of the friction ring 4. Figure 4 corresponds to a cross-sectional view of the sheet winding shaft 1 in this state. In Figure 4, the gripping device 6 is located at the raised portion 45 of the friction ring 4, and the abutment portion 63 protrudes from the outer surface of the exterior collar 5 and abuts against the inner peripheral surface of the winding core 10. In this state, the base shaft can be rotated clockwise (in the direction of arrow a) to wind the sheet onto the winding core 10. When the sheet is wound, the raised portion 45 of the friction ring 4 presses against the bottom of the gripping device 6, maintaining the gripping device 6 in abutment against the inner peripheral surface of the winding core 10. This allows the exterior collar 5 to rotate together with the friction ring 4 without slipping relative to the friction ring 4.

[0055] In Figure 1, multiple winding cores 10 can be attached to the sheet winding shaft 1, allowing sheets to be wound onto multiple winding cores at the same time. The length of the winding core 10 is not necessarily equal to the length of the winding section 3, and multiple winding sections 3 may correspond to one winding core 10. In this case, if the number of contact portions 63 corresponding to each winding core 10 is not the same, the number of contact portions 63 contacting each winding core 10 can be made to match by recessing the contact portions 63 for a specific winding section 3. In this case, the winding rotation torque for each winding core 10 becomes more uniform.

[0056] Specifically, the specific winding unit 3 in which the contact portions 63 need to be buried can be determined in advance if the length and number of winding cores 10 are known. Therefore, for this specific winding unit 3, before the winding core 10 is attached, the gripping device 6 is brought into a state where it is completely buried in the opening 51, as shown in Figure 6, and the rotation prevention means 7 is operated to restrict the relative rotation between the friction ring 4 and the exterior collar 5, as shown in Figures 7 and 8. This makes it possible to match the number of contact portions 63 that come into contact with each winding core 10, and by maintaining the state in which the hook portions 62 of the gripping device 6 and the protrusions 44 of the friction ring 4 are engaged, it is possible to prevent the gripping devices 6 that are not in contact with the winding core 10 from protruding from the outer surface of the exterior collar 5 due to centrifugal force and coming into contact with the winding core 10.

[0057] When the winding of the sheet onto the core 10 is completed, the outer collar 5 is manually rotated clockwise (in the direction of arrow a) from the state shown in Figure 4 to the state shown in Figure 6 in which the gripping device 6 is buried. In this state, the wound product with the sheet wound onto the core 10 can be removed from the sheet winding shaft 1.

[0058] Having described the first embodiment of the present invention, we now describe a second embodiment of the present invention. The second embodiment has the same basic configuration and operation as the first embodiment, and differences from the first embodiment will be described below. Figure 13 is a perspective view showing the engagement state of the friction ring 4a with the gripper 6a and the anti-rotation means 7 in the second embodiment. The friction ring 4a of the second embodiment has a different shape of the thick portion compared to the friction ring 4 of the first embodiment (see Figure 8).

[0059] 13, the friction ring 4a has an engaging protrusion 47 formed on its outer circumferential surface. One end of the engaging protrusion 47 is formed with a protrusion 44a that engages with the hook portion 62a of the gripper 6a, and the other end is formed with an abutment surface 48 that abuts against the protrusion 71 of the rotation prevention means 7. The friction ring 4a does not have the groove 42 and narrow groove 43 that are provided on the friction ring 4 shown in FIG. 8. Therefore, a long, gently sloping portion 41a is formed between two adjacent engaging protrusions 47.

[0060] FIG. 14 is a cross-sectional view of a sheet winding shaft 1a according to a second embodiment, corresponding to FIG. 4 of the first embodiment. In FIG. 14, a gripper 6a is located on the raised portion 45a of the friction ring 4a, with a contact portion 63a protruding from the outer peripheral surface of the exterior collar 5a. A magnetic body similar to the magnetic body 64 shown in FIGS. 3 and 5 is disposed at the portion of the gripper 6a that contacts the inclined portion 41a. As in the first embodiment, when the exterior collar 5a is rotated relative to the friction ring 4a, the gripper 6a moves along the inclined portion 41a while maintaining contact with the friction ring 4a due to the magnetic force of the magnetic body. As this movement progresses, the gripper 6a approaches the sunken portion 46a of the inclined portion 41a, and the gripper 6a sinks further into the opening 51a.

[0061] Figure 15 shows a cross-sectional view of the sheet winding shaft 1a with the gripping device 6a completely buried. In the state shown in Figure 15, the gripping device 6a is completely buried in the opening 51a, and the contact portion 63a of the gripping device 6a does not protrude from the outer peripheral surface of the exterior collar 5a. In this state, the contact portion 63a moves away from the winding core 10, and the gripping device 6a releases the winding core 10 from its fixed state.

[0062] In the second embodiment, as in the first embodiment, the relative rotation between the friction ring 4a and the exterior collar 5a is restricted in order to restrict the movement of the abutting portion 63a of the gripping tool 6a in the direction of protruding from the outer peripheral surface of the exterior collar 5a. For this reason, in the second embodiment as well, the winding portion 3a is provided with the rotation prevention means 7 shown in Figures 2 and 7.

[0063] 16 is a cross-sectional view of the vicinity of the rotation prevention means 7 in the second embodiment, and corresponds to Fig. 7 of the first embodiment. In this state, clockwise rotation of the friction ring 4a (in the direction of arrow C) is limited by the abutment surface 48 of the engaging convex portion 47 abutting against the convex portion 71 of the rotation prevention means 7, and counterclockwise rotation of the friction ring 4a (in the direction of arrow d) is limited by the abutment of the protrusion 44a of the engaging convex portion 47 with the hook portion 62a of the gripper 6a.

[0064] That is, unlike the first embodiment, the second embodiment does not have a configuration in which the protrusion 71 engages with the narrow groove 43 (see FIG. 7 ). However, similar to the first embodiment, the rotation prevention means 7 can limit the relative rotation between the friction ring 4 a and the exterior collar 5 a.

[0065] The operation of the rotation prevention means 7 in the second embodiment is the same as that in the first embodiment, as described with reference to FIG. 10 . In FIG. 10 , in the first embodiment, the rotation of the convex portion 71 is not restricted by the narrow groove 43 or the groove 42. Therefore, even in the second embodiment, in which the narrow groove 43 or the groove 42 is not provided, the rotation of the convex portion 71 is the same as in the first embodiment. In the second embodiment, as shown in FIG. 13 , the groove 49 is formed. Therefore, when the rotation prevention by the rotation prevention means 7 is released as shown in FIG. 10( a), the rotation prevention means 7 can move along the groove 49 together with the rotation of the exterior collar 5 a. By utilizing the groove 49, the plunger 8 can also limit misalignment of the axial position between the exterior collar 5 a and the friction ring 4 a.

[0066] The second embodiment has been described above. As described above, in the second embodiment, as shown in Fig. 13, a long, gently inclined portion 41a is formed between two adjacent engaging protrusions 47. Therefore, in Fig. 14, a long, gently inclined portion 41a extends between two adjacent gripping tools 6a. In this case, the circumferential length between the two gripping tools 6a is the same as the circumferential length between the two adjacent gripping tools 6 in Fig. 4, but the length of the inclined portion 41a in Fig. 14 is longer than the length of the inclined portion 41 in Fig. 4.

[0067] With this configuration, when the gripping tool 6a moves from the state shown in FIG. 15 in which it is lowered to the state shown in FIG. 14 in which it is protruding, the gripping force of the gripping tool 6a on the winding core 10 is greater than that of the case shown in FIG. 4 in which the sliding distance is shorter, even if the rotational torque per winding section 3, 3a on the sheet winding spindle 1, 1a is the same. With this sheet winding spindle 1a, the gripping tool 6a maintains its protruding force by utilizing the rotational torque of the winding section 3a on the sheet winding spindle 1a. When the winding diameter is small or the rotational torque is low due to low winding tension, the gripping force on the winding core 10 also decreases. In this case, if the inclined portion 41a is gentle, the force required to grip the winding core 10 can be easily obtained even with a low rotational torque. For these reasons, the winding core 10 can be gripped more reliably.

[0068] 10, the rotation prevention means 7 can be rotated without interfering with the wall surfaces of the groove 42 and the narrow groove 43, but this requires that the components be aligned to avoid interference when assembled. In the second embodiment, the groove 42 and the narrow groove 43 are not provided (see FIG. 13), which reduces the burden of alignment.

[0069] Furthermore, in the second embodiment, as shown in FIG. 16 , the engaging protrusion 47 is formed with an abutment surface 48. The abutment surface 48 is the abutment surface of the protrusion 71 of the rotation prevention means 7, but the gripper 6a may also abut against it. This point will be explained with reference to FIG. 17 . FIG. 17 is a schematic diagram of the gripper 6a in FIG. 14 when it is extended until the gripper 6a and the abutment surface 48 of the engaging protrusion 47 abut against each other. For convenience, the gripper 6a is illustrated as a side view rather than a cross-sectional view. In this abutting state, there is a slight gap between the protrusion 61a (barb) that prevents the gripper 6a from falling (detaching) and the exterior collar 5a. If the abutment surface 48 were not present and the gripping tool 6a could be allowed to protrude beyond a certain amount, if the gripping tool 6a protruded too far, the convex portion 61a of the gripping tool 6a would come into contact with the inner surface of the exterior collar 5a, and the gripping tool 6a would be pinched between the exterior collar 5a and the friction ring 4a by the convex portion 61a, which could cause the gripping tool 6a to become locked in a protruding position. Because the gripping tool 6a is not a roller, the possibility of such locking occurring is low, but by limiting the protrusion with the abutment surface 48, locking can be prevented more reliably.

[0070] It is difficult to achieve a state in which the contact surface 48 and the gripping tool 6a are in contact as shown in Figure 17 when the protrusion of the gripping tool 6a is limited by its contact with the inner surface of the winding core 10, and this state can mainly be achieved when the winding core 10 is not attached. If the contact surface 48 and the gripping tool 6a are in contact even when the winding core 10 is attached, there is a possibility that the gripping tool 6a is not in sufficient contact with the inner surface of the winding core 10. When the contact surface 48 and the gripping tool 6a are in contact, the gripping tool 6a cannot protrude any further, so it is preferable to change the winding core 10 to one with a slightly smaller inner diameter so that the gripping tool 6a sufficiently abuts the inner surface of the winding core 10 before it protrudes to its maximum extent. Therefore, it is preferable that the contact surface 48 and the gripping tool 6a are not in contact when the winding core 10 is attached.

[0071] The above describes the embodiments of the present invention, but these are merely examples and may be modified as appropriate. For example, the groove 42 shown in Fig. 8 is provided to prevent interference with the anti-rotation means 7 and plunger 8, and the formation of the groove 42 is optional. The groove 49 shown in Fig. 13 may be provided only in the engaging protrusion 47, or may be formed to extend from the engaging protrusion 47 to the inclined portion 41a along the axial circumferential direction of the friction ring 4a.

[0072] REFERENCE SIGNS LIST 1, 1a Sheet winding shaft 2 Base shaft 3, 3a Winding portion 4, 4a Friction ring 5, 5a Exterior collar 6, 6a Grip 7 Rotation prevention means 8 Plunger 10 Winding core 21 Fluid path 22 Connection hole 23 Rotation torque adjustment means 41, 41a Inclined portion 42 Groove 43 Narrow groove 44, 44a Protrusion 45, 45a Raised portion 46, 46a Sinking portion 47 Engaging protrusion 48 Contact surface 51, 51a Opening 62, 62a Hook portion 63, 63a Contact portion 64 Magnetic body

Claims

DEPCT661. Plate tensioning shaft for adjusting plate tension on an axis, which includes: a base shaft; tensioning elements fitted onto the base shaft, with several tensioning elements arranged side-by-side; and a method for adjusting rotational torque, constructed in a configuration to adjust rotational torque between the tensioning elements and the base shaft, where the tensioning elements include: a friction ring with several inclined sections on the outer circumference of the friction ring, which form a raised and lowered outline along the axial direction; an outer sleeve to which the friction ring is fitted; a gripping piece fitted into an opening provided in the outer sleeve, which moves along the inclined sections and grips the axis by extending outwards from the outer sleeve when the gripping piece is at the raised section of the inclined section; and an anti-rotation method that limits the relative rotation between the friction ring and the outer sleeve and gripping piece, which includes: a bracing element for bracing against the inner circumference of the axis.and the hooking element for coupling with the friction ring when the workpiece is held in the recessed section of the inclined section; 2. Plate tensioning shaft according to Reputation 1 where the workpiece includes magnetic material in one section where the workpiece is pressed against the inclined section of the friction ring; 3. Plate tensioning shaft according to Reputation 1 where the outer sleeve is provided with a push rod that contacts the inner perimeter of the rod; 4. Any one of the plate tensioning shafts according to Reputations 1 to 3 where a coupling projection is formed on the outer perimeter surface of the friction ring, the projection that interlocks with the hooking element of the workpiece is formed at one end of the coupling projection, and the contact surface where the anti-rotation path is pressed against the other end of the coupling projection; 5. Any one of the plate tensioning shafts according to Reputations 1 to 3 where the friction ring includes axially protruding narrow grooves and an anti-rotation path that is coupling to limit the relative rotation between the friction ring and the outer sleeve;