Roll holding mechanism and roll holding device

Abstract

To provide a roll holding mechanism that can generate sufficient force to fix a roll while simplifying the structure, and a roll holding device equipped with such a roll holding mechanism. [Solution] A roll holding mechanism 1 that holds a roll R and unwinds a sheet S comprises a rotatable shaft portion 5 that is inserted into the core C of the roll R and has a cross section that is rotationally symmetrical about the central axis, and a fixing portion 10 that is provided on the side of the shaft portion 5 and fixes the roll R to the shaft portion 5, the fixing portion 10 having three contact members 11 whose axial directions are parallel to the central axis of the shaft portion 5 and that are provided in positions that are rotationally symmetrical about the central axis of the shaft portion 5, and a moving mechanism 15 that moves the three contact members 11 toward and away from the side of the shaft portion 5 in a direction perpendicular to the axial direction of the shaft portion 5, the moving mechanism 15 comprising: The contact members 11 are configured to move while maintaining the axial direction of the contact members 11 parallel to the central axis of the shaft portion 5 .

Description

[Technical Field]

[0001] The present invention relates to a roll holding mechanism and a roll holding device, and more particularly to a roll holding mechanism that holds a roll in which a sheet or film is wound around a core material, and a roll holding device equipped with such a roll holding mechanism. [Background technology]

[0002] Resin films and sheets are used to package various items. In packaging machines, films and sheets (hereinafter sometimes referred to as "films, etc.") are supplied from a roll (hereinafter sometimes simply referred to as a "roll") in which the film or sheet is wound around a core material to perform packaging. In such packaging machines, the core material of the roll is attached to a rotating shaft, and the film or sheet is unwound by rotating the roll and supplied to the packaging section. Therefore, when a high-speed supply of film or sheet is required to a packaging machine, the roll must be fixed to the shaft to prevent the core material from coming off the shaft as the roll rotates at high speed. Furthermore, when packaging is performed intermittently, the film or sheet is repeatedly unwound and stopped at high speed, and the roll also rotates and stops at high speeds repeatedly. As a result, when the roll switches between rotating and stopping, the roll may rotate relative to the shaft, causing it to become misaligned. To prevent this, the roll must be fixed to the shaft.

[0003] Patent Document 1 discloses a holding mechanism for holding a roll with an expansion / contraction mechanism attached to a shaft inserted through the roll. This holding mechanism includes an expansion / contraction base attached to a shaft-shaped mounting body inserted through the roll, and four expansion / contraction bodies whose base ends are connected to the expansion / contraction base and whose tips can swing radially apart around the base end as a fulcrum. The holding mechanism also includes an expansion / contraction body attached to the mounting body so as to be movable along its axial direction. The expansion / contraction body includes a wedge-shaped portion on the expansion / contraction body side that reduces in diameter as it approaches the expansion / contraction body. A locking device is attached to the male thread of the mounting body, moving the expansion / contraction body along the axial direction of the mounting body. Therefore, by inserting the mounting body of the holding mechanism into the core material of the roll and then tightening the locking device to move the expansion / contraction body toward the expansion / contraction body, the tips of the four expansion / contraction bodies will open radially and come into contact with the inner surface of the core material, thereby securing the roll to the mounting body of the holding mechanism. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-46477 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the technology disclosed in Patent Document 1, the tip of the expander body opens and comes into contact with the core material of the roll, which reduces the contact area between the expander body and the roll, thereby reducing the force that secures the roll. Moreover, the expander mechanism is made up of many parts, making it complex.

[0006] In view of the above circumstances, the present invention aims to provide a roll holding mechanism that can generate sufficient force to fix a roll while simplifying the structure, and a roll holding device equipped with such a roll holding mechanism. [Means for solving the problem]

[0007] <Roll holding mechanism> The roll holding mechanism of the first invention is a roll holding mechanism that holds a roll and unwinds a sheet wound on the roll, and is equipped with a rotatable shaft portion that is inserted into the core of the roll and has a cross section that is rotationally symmetrical about a central axis, and a fixing portion that fixes the roll to the shaft portion, the fixing portion having three contact members whose axial directions are parallel to the central axis of the shaft portion and positioned rotationally symmetrical about the central axis of the shaft portion, and a moving mechanism that moves the three contact members toward and away from the side of the shaft portion in a direction perpendicular to the axial direction of the shaft portion, and the moving mechanism is configured to move each contact member while keeping the axial direction of the contact member parallel to the central axis of the shaft portion. The roll holding mechanism of the second invention is characterized in that, in the first invention, the moving mechanism includes a holding member having a guide wall provided on the side of the shaft portion that is parallel to the central axis direction of the shaft portion, and a guide shaft provided on the guide wall of the holding member so that its axial direction intersects with the central axis direction of the shaft portion, movably connecting the guide wall of the holding member and the contact member, and the contact member has a guide groove formed in the side surface facing the guide wall of the holding member, the axial direction of which is inclined with respect to the central axis direction of the shaft portion, and the guide shaft is arranged within the guide groove so as to be movably arranged along the axial direction of the guide groove. The roll holding mechanism of the third invention is characterized in that, in the second invention, three holding members are provided, each holding member has a fixed wall connected to a side surface of the shaft portion, and a pair of guide walls are provided on the fixed wall, the three holding members are positioned rotationally symmetrically about the central axis of the shaft portion, three contact members are provided between the guide walls of adjacent holding members, the guide grooves of the contact members are formed so as to pass through a pair of side surfaces facing the guide walls of the adjacent holding members, and the guide shaft is inserted into the guide groove of the contact member, and both ends of the guide shaft are fixed to the guide walls of the adjacent holding members, respectively. The roll holding mechanism of the fourth invention is characterized in that, in the first invention, the moving mechanism includes a holding member having a guide wall provided on the side of the shaft portion and parallel to the central axis direction of the shaft portion, and a guide shaft that movably connects the guide wall of the holding member and the contact member and is provided so that its axial direction intersects with the central axis direction of the shaft portion, and the guide shaft is provided on the contact member so that its tip protrudes from the side of the contact member that faces the guide wall of the holding member, and the tip is inserted movably along the axial direction of the guide groove formed in the guide wall of the holding member and whose axial direction is inclined with respect to the central axis direction of the shaft portion. The roll holding mechanism of the fifth invention is characterized in that, in the fourth invention, three holding members are provided, each holding member has a fixed wall connected to the side of the shaft portion, a pair of guide walls are provided on the fixed wall, the three holding members are provided in positions that are rotationally symmetrical with respect to the central axis of the shaft portion, three contact members are provided between the guide walls of adjacent holding members, and both ends of the guide shaft are movably inserted into the guide grooves formed in the guide walls of the adjacent holding members. The roll holding mechanism of the sixth invention is characterized in that, in any of the second to fifth inventions, the guide groove provided in the contact member or the guide groove provided in the guide wall of the holding member is inclined away from the side surface of the shaft portion from one end to the other end of the shaft portion, and the moving mechanism has a moving member that moves toward and away from one end face of the shaft portion along the central axial direction of the shaft portion, and the moving member is configured to contact the edge of one end side of the shaft portion of the three contact members when it moves from one end to the other end of the shaft portion, thereby moving the three contact members toward the other end side of the shaft portion. The roll holding mechanism of the seventh invention is characterized in that, in the sixth invention, the distance from the central axis of the shaft portion to the outer edge of the moving member in a direction perpendicular to the central axis direction of the shaft portion is shorter than the distance from the central axis of the shaft portion to the outer edge of the contact member in a direction perpendicular to the central axis direction of the shaft portion when the three contact members are brought close to the side of the shaft portion. The roll holding mechanism of the eighth invention is the roll holding mechanism of the first invention, characterized in that the cross section of the shaft member is a regular hexagon. The roll holding mechanism of the ninth invention is characterized in that, in the first invention, the contact member has an outer surface parallel to the central axis direction of the shaft portion located on the opposite side of the shaft portion, and a pair of side surfaces parallel to the central axis direction of the shaft portion that intersect with the outer surface, and corners are formed between each of the pair of side surfaces and the outer surface. <Roll holding device> A roll holding device of the tenth invention is a roll holding device that holds a roll and unwinds the sheet, and is characterized by including the roll holding mechanism according to any one of the first to ninth inventions. [Effects of the Invention]

[0008] <Roll holding mechanism> According to the first aspect of the present invention, the roll can be held by the roll holding mechanism by moving the three contact members away from the side of the shaft portion (in other words, approaching the inner surface of the roll core) while the shaft portion is inserted into the roll core. Moreover, the cross section of the shaft portion is rotationally symmetrical with respect to the central axis, and the three contact members are provided at positions that are rotationally symmetrical with respect to the central axis of the shaft portion. Therefore, the roll can be held with the roll core and the central axis of the shaft portion aligned, allowing the roll to rotate stably. According to the second invention, the contact member can be moved along the guide groove while being guided by the guide shaft, so that the axial direction of the contact member can be moved while being maintained parallel to the central axis of the shaft portion. According to the third aspect of the present invention, the three contact members can be positioned by the three holding members, so that the three contact members can be reliably and easily positioned and arranged in positions that are rotationally symmetrical about the central axis of the shaft portion. According to the fourth aspect of the present invention, the contact member can be moved along the guide groove while being guided by the guide shaft, so that the axial direction of the contact member can be moved while being maintained parallel to the central axis of the shaft portion. According to the fifth aspect of the present invention, the three contact members can be positioned by the three holding members, so that the three contact members can be reliably and easily positioned and arranged in positions that are rotationally symmetrical about the central axis of the shaft portion. According to the sixth aspect of the present invention, the roll can be easily held in or released from the roll holding mechanism by simply moving the movable member toward or away from one end face of the shaft portion along the central axis direction of the shaft portion, thereby facilitating the work of attaching and removing the roll. According to the seventh aspect of the present invention, the roll mounting work becomes easier. According to the eighth aspect of the present invention, the contact members can be easily arranged. According to the ninth aspect of the present invention, the two corners of the contact member can be caused to bite into the core material of the roll, so that the roll can be firmly fixed. <Roll holding device> According to the tenth aspect of the present invention, the roll can be held securely and easily, allowing the roll to rotate in a stable state. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic side view of a roll holding mechanism 1 of the present embodiment. [Figure 2] FIG. 2 is a schematic side view of the roll holding mechanism 1 of the present embodiment with a holding member 16 removed. [Figure 3] (A) is a schematic end view of the roll holding mechanism 1 of this embodiment in a state where the three contact members 11 are close to the side surface 7a of the roll holding shaft portion 7 of the shaft portion 5, (B) is a schematic cross-sectional view of the roll holding mechanism 1 of this embodiment in a state where the three contact members 11 are away from the side surface 7a of the roll holding shaft portion 7 of the shaft portion 5, and (C) is a schematic end view of the roll holding mechanism 1 of this embodiment in a case where the cross section of the roll holding shaft portion 7 is circular. [Figure 4] 10A to 10C are schematic explanatory views of the operation of attaching and detaching the roll R to and from the roll holding mechanism 1 of the present embodiment. [Figure 5] FIG. 10 is a schematic side view of a roll holding mechanism 1B according to another embodiment. [Figure 6]FIG. 10 is a schematic side view of a roll holding mechanism 1B according to another embodiment, with a holding member 16B removed. [Figure 7] (A) is a schematic end view of the roll holding mechanism 1B of this embodiment in a state where the three contact members 11B are close to the side surface 7a of the roll holding shaft portion 7 of the shaft portion 5, (B) is a schematic cross-sectional view of the roll holding mechanism 1B of this embodiment in a state where the three contact members 11B are away from the side surface 7a of the roll holding shaft portion 7 of the shaft portion 5, and (C) is a schematic end view of the roll holding mechanism 1B of this embodiment in a case where the cross section of the roll holding shaft portion 7 is circular. [Figure 8] 10A and 10B are schematic explanatory views of the operation of attaching and detaching the roll R to and from the roll holding mechanism 1B of another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The roll holding mechanism of the present invention is a mechanism installed in a device that unwinds sheets, films, etc. wound onto a roll in a production line, etc., and is characterized by being able to rotate the roll stably and also making it easy to attach and detach the roll.

[0011] The device in which the roll holding mechanism of the present invention is installed is not particularly limited. For example, the device in which the roll holding mechanism of the present invention is installed can be used in a device that supplies packaging sheets, films, etc. to a device that packages products. Such a device in which the roll holding mechanism of the present invention is installed corresponds to the roll holding device of the present invention.

[0012] The roll held by the roll holding mechanism of the present invention is not particularly limited. For example, a roll in which a paper or resin film or the like is wound around a paper or resin core can be cited as a roll that can be held by the roll holding mechanism of the present invention. For example, a roll in which a film or the like is wound around a paper core with an inner diameter of approximately 3 inches is suitable as a roll that can be held by the roll holding mechanism of the present invention. In addition, the outer diameter of the roll, i.e., the outer diameter of the roll when the film or the like is wound around it, and the axial length of the roll are not particularly limited, but rolls with an outer diameter of up to approximately 1000 mm and axial lengths of up to approximately 1000 mm can be held by the roll holding mechanism of the present invention.

[0013] <Roll holding mechanism 1> The roll holding mechanism 1 of this embodiment will be described with reference to the drawings.

[0014] <Shaft 5> In FIGS. 1 and 2, reference numeral 5 denotes a shaft portion of the roll holding mechanism 1 of this embodiment. Specifically, the shaft portion 5 has a base end portion 6 and a roll holding shaft portion 7 continuing from the base end portion 6. The base end portion 6 is formed in a cylindrical shape with a circular cross section and is supported by a bearing provided on a frame of the roll holding mechanism 1 (not shown) so as to be rotatable about its central axis 6s. The roll holding shaft portion 7 is a shaft-shaped portion whose base end is connected to the tip of the base end portion 6 and whose central axis 7s is coaxial with the central axis 6s of the base end portion 6. The roll holding shaft portion 7 has a cross section formed into a regular hexagon (see FIGS. 3(A) and (B)). In other words, the roll holding shaft portion 7 is formed rotationally symmetrical with respect to its central axis 7s. Therefore, the roll holding shaft portion 7 is formed so that all six side surfaces are parallel to its central axis 7s.

[0015] Although all six side surfaces of the roll holding shaft portion 7 have substantially the same shape, the six side surfaces are hereinafter referred to as side surfaces 7a and side surfaces 7b for convenience. In other words, the following description will be given assuming that the side surfaces 7a and 7b are alternately arranged along the circumferential direction of the roll holding shaft portion 7 (see FIGS. 3A and 3B). In other words, the roll holding shaft portion 7 will be described as having three side surfaces 7a and three side surfaces 7b, with the three side surfaces 7a positioned at 120° intervals around the central axis 7s of the roll holding shaft portion 7, and the three side surfaces 7b also positioned at 120° intervals around the central axis 7s of the roll holding shaft portion 7. Furthermore, the side surfaces 7a of the roll holding shaft portion 7 of the shaft portion 5 may be referred to simply as "side surfaces 7a," and the side surfaces 7b of the roll holding shaft portion 7 of the shaft portion 5 may be referred to simply as "side surfaces 7b."

[0016] <Fixed part 10> 1 and 2, a fixed portion 10 is provided on the roll holding shaft portion 7 of the shaft portion 5. This fixed portion 10 has three contact members 11 and a movement mechanism 15 that moves the three contact members 11.

[0017] <Contact member 11> As shown in FIG. 3, the three contact members 11 are plate-like (strip-like) members formed with the same shape (rectangular cross section, rectangular cross section in FIG. 3). The three contact members 11 are provided on three side surfaces 7a of the roll holding shaft portion 7 of the shaft portion 5. That is, the three contact members 11 are respectively installed at the positions of the three side surfaces 7a via a movement mechanism 15. The three contact members 11 have inner surfaces 11a and outer surfaces 11b that are parallel to each other (see FIGS. 2 and 3(B)). The three contact members 11 are all provided so that the inner surface 11a faces the side surface 7a on which each contact member 11 is provided and the inner surface 11a is parallel to the side surface 7a. In other words, the three contact members 11 are all provided so that the outer surface 11b located on the opposite side to the side surface 7a on which each contact member 11 is provided is parallel to the side surface 7a on which each contact member 11 is provided. Each of the three contact members 11 has a pair of side surfaces 11c, 11c that intersect with the outer surface 11a (see FIGS. 3A and 3B). When each contact member 11 is attached to the side surface 7a, the pair of side surfaces 11c, 11c are arranged so that their surfaces are parallel to the central axis direction of the roll holding shaft portion 7 of the shaft portion 5. Furthermore, the pair of side surfaces 11c, 11c are formed so that a ridge line 11e (see FIG. 3B) formed between the pair of side surfaces 11c, 11c and the outer surface 11b is a somewhat sharp corner. For example, when the angle formed between the pair of side surfaces 11c, 11c and the outer surface 11b is θ, the pair of side surfaces 11c, 11c are arranged so that θ=90°.

[0018] As shown in FIGS. 1, 2, and 3(B), the contact member 11 is provided with a plurality of guide grooves 11g that communicate between a pair of side surfaces 11c, 11c. The plurality of guide grooves 11g are provided parallel to one another and are inclined with respect to the central axis 7s of the roll holding shaft portion 7 of the shaft portion 5 when each contact member 11 is provided on the side surface 7a. Specifically, the guide grooves 11g are provided such that their axial direction moves away from the side surface 7a (inclined upward in FIGS. 1 and 2) as they extend from a first end (the end portion on the tip side of the roll holding shaft portion 7 (the end portion opposite the base end portion 6), the left end in FIGS. 1 and 2; hereinafter, sometimes simply referred to as the "first end of the guide grooves 11g") to a second end (the end portion on the base end side of the roll holding shaft portion 7 (the end portion on the base end portion 6 side), the right end in FIGS. 1 and 2; hereinafter, sometimes simply referred to as the "second end of the guide grooves 11g"). In other words, the guide groove 11g is formed so that when each contact member 11 is provided on the side surface 7a, it is inclined from the first end toward the second end, and the second end is positioned farther away from the side surface 7a than the first end.

[0019] <Movement mechanism 15> The fixed unit 10 includes a moving mechanism 15 that moves the three contact members 11. Specifically, the moving mechanism 15 moves the outer surfaces 11b of the three contact members 11 toward or away from the side surface 7a in the radial direction (i.e., the direction perpendicular to the central axis 7s of the roll holding shaft unit 7) while maintaining the outer surfaces 11b of the three contact members 11 parallel to the side surface 7a. The moving mechanism 15 includes three holding members 16 and a moving member 20 that have the same shape and structure.

[0020] <Retaining member 16> 3, the three holding members 16 of the movement mechanism 15 are respectively provided on the side surfaces 7b of the roll holding shaft portion 7 of the shaft portion 5. In other words, when the roll holding shaft portion 7 of the shaft portion 5 is viewed from the axial direction, the three holding members 16 are provided on the roll holding shaft portion 7 of the shaft portion 5 so that the contact members 11 and the holding members 16 are arranged alternately along the circumferential direction.

[0021] As shown in FIGS. 1 and 3, the holding member 16 is formed by bending a single elongated plate material and includes a fixed wall 17 extending in the longitudinal direction (left-right direction in FIG. 1) and a pair of guide walls 18, 18 provided at both ends of the fixed wall 17 in the width direction and extending in the longitudinal direction (left-right direction in FIG. 1). The fixed wall 17 is fixed to the side surface 7b and is attached to the side surface 7b with its inner surface in contact with the side surface 7b. The pair of guide walls 18, 18 are provided so that the angle θ2 (see FIG. 3(A)) formed with the fixed wall 17 of the holding member 16 is 150°. In other words, when the fixed wall 17 is attached to the side surface 7b, the surface of the pair of guide walls 18, 18 is perpendicular to the side surface 7a adjacent to the side surface 7b to which the fixed wall 17 is attached, and each guide wall 18 is perpendicular to the side surface 7a adjacent to the side surface 7b to which the fixed wall 17 is attached. In other words, when the fixed wall 17 is attached to the side surface 7b, the pair of guide walls 18, 18 are arranged so that the guide walls 18 of adjacent holding members 16 sandwich the adjacent side surface 7a between them. In other words, when the fixed wall 17 is attached to the side surface 7b, the pair of guide walls 18, 18 are arranged so that the guide walls 18 of adjacent holding members 16 sandwich the contact member 11 provided on the adjacent side surface 7a between them. Hereinafter, the guide walls 18 of adjacent holding members 16 that sandwich the contact member 11 may be referred to as a guide wall pair 18t.

[0022] As shown in FIG. 1, a plurality of guide shafts 19 are provided on the pair of guide walls 18, 18 so as to connect them. The plurality of guide shafts 19 are provided so as to be parallel to each other and to the surface of the side surface 7a on which the contact member 11 is provided (see FIG. 3(B)). In other words, the plurality of guide shafts 19 are provided so as to be perpendicular to the central axis 7s of the roll holding shaft portion 7. The plurality of guide shafts 19 are inserted into the plurality of guide grooves 11g of the contact member 11, respectively. Specifically, the plurality of guide shafts 19 are inserted into the plurality of guide grooves 11g so as to be movable along the axial direction of the plurality of guide grooves 11g.

[0023] With the above-described configuration, the contact member 11 is capable of moving toward and away from the side surface 7a while being guided by the plurality of guide grooves 11g and the plurality of guide shafts 19, with its movement in the width direction being restricted by the pair of guide walls 18t.

[0024] As described above, the guide groove 11g formed in the contact member 11 is inclined from the first end toward the second end, so that when the contact member 11 approaches or moves away from the side surface 7a, it moves along the central axis direction of the roll holding shaft 7. More specifically, when the contact member 11 approaches the side surface 7a, it moves from the base end toward the tip along the central axis direction of the roll holding shaft 7, and when it moves away from the side surface 7a, it moves from the tip toward the base end along the central axis direction of the roll holding shaft 7.

[0025] <Moving member 20> As shown in FIGS. 1 and 2, a threaded hole 7h is formed at the tip of the roll holding shaft 7. This threaded hole 7h is formed coaxially with the central axis 7s of the roll holding shaft 7, and a male screw 21n provided at the tip of the shaft 21 of the moving member 20 is threadedly engaged with this threaded hole 7h. A handle 22 is provided at the base end of the shaft 21 of the moving member 20, and a pressing member 23 is provided between the handle 22 and the portion of the shaft 21 where the male screw 21n is formed. This pressing member 23 has a pressing surface 23a on the tip side of the shaft 21 that is perpendicular to the axial direction of the shaft 21. This pressing surface 23a is a surface perpendicular to the central axis 21s of the shaft 21 of the moving member 20. In other words, the pressing surface 23a is formed so that when the male screw 21n of the shaft 21 of the moving member 20 is threadedly engaged with the threaded hole 7h, the pressing surface 23a becomes a surface perpendicular to the central axis 7s of the roll holding shaft 7.

[0026] Furthermore, the pressing member 23 is configured such that the distance L1 (see FIG. 1) from its central axis, i.e., the central axis 21s of the shaft portion 21, to its outer edge 23e is shorter than the distance L2 (see FIG. 4(F)) from the outer surface 11b of the contact member 11 to the central axis 7s of the roll holding shaft portion 7 when the contact member 11 is close to the side surface 7a, i.e., when the guide shaft 19 has moved to the second end. In other words, the pressing member 23 is configured such that the distance L1 is shorter than the inner diameter (radius) of the core material C of the roll R held by the roll holding mechanism 1. Moreover, the distance L1 is longer than the distance L3 (see FIG. 4(D)) from the inner surface 11a of the contact member 11 to the central axis 7s of the roll holding shaft portion 7 when the guide shaft 19 has moved to the first end. Like the pressing member 23, the handle 22 is also designed so that the distance from the central axis 21s of the shaft portion 21 to the outer edge of the handle 22 is shorter than the inner diameter (radius) of the core material C of the roll R held by the roll holding mechanism 1. In the following, the outer diameter of the pressing member 23 may be referred to as twice the distance L1 from the central axis 21s of the shaft portion 21 to the outer edge 23e of the pressing member 23, and the outer diameter of the handle 22 may be referred to as twice the distance from the central axis 21s of the shaft portion 21 to the outer edge 23e of the pressing member 23.

[0027] Therefore, when the handle 22 is grasped and the male screw 21n of the shaft 21 of the moving member 20 is screwed into the threaded hole 7h at the tip of the roll holding shaft 7, the pressing surface 23a of the pressing member 23 comes into contact with the tips of the contact members 11. More specifically, the pressing surface 23a of the pressing member 23 comes into contact with the three contact members 11 simultaneously. When the male screw 21n of the shaft 21 is further screwed into the threaded hole 7h at the tip of the roll holding shaft 7 from the state in which the pressing surface 23a of the pressing member 23 is in contact with the tips of the three contact members 11, the pressing member 23 moves the contact members 11 from the tip toward the base end of the roll holding shaft 7. More specifically, the pressing members 23 simultaneously move the contact members 11 by the same amount from the tip toward the base end of the roll holding shaft 7. Here, movement of the contact members 11 is restricted by a plurality of guide shafts 19 provided in the guide wall pair 18t and a guide groove 11g formed in the contact members 11. Therefore, by screwing the male thread 21n of the shaft portion 21 into the screw hole 7h at the tip of the roll holding shaft portion 7, the contact members 11 can be moved from the tip toward the base end of the roll holding shaft portion 7 and can also be moved in a direction away from the side surface 7a (see FIG. 4). More specifically, because the three contact members 11 and the three holding members 16 have the same shape, the three contact members 11 can be simultaneously moved the same amount from the tip toward the base end of the roll holding shaft portion 7 and can also simultaneously moved the same amount in a direction away from the side surface 7a.

[0028] Furthermore, if the male screw 21n of the shaft portion 21 of the movable member 20 is screwed into the screw hole 7h and the contact member 11 is spaced away from the side surface 7a, and then the male screw 21n of the shaft portion 21 is loosened from the screw hole 7h, the contact member 11 can be moved from a spaced-away state to a direction approaching the side surface 7a.

[0029] If the roll holding mechanism 1 is provided so that the shaft 5 is horizontal, the contact member 11 located vertically above the central axis 7s of the roll holding shaft 7 can be moved from a position away from the side surface 7a toward the side surface 7a by loosening the male screw 21n of the shaft 21 from the screw hole 7h, as described above. In other words, the weight of the contact member 11 can move the contact member 11 from a position away from the side surface 7a toward the side surface 7a. On the other hand, the contact member 11 located vertically below the central axis 7s of the roll holding shaft 7 cannot be moved from a position away from the side surface 7a toward the side surface 7a by the method described above. However, a biasing mechanism is provided that constantly biases the contact member 11 from the base end toward the tip end along the axial direction of the roll holding shaft 7. Then, regardless of the vertical position of the contact member 11 relative to the central axis 7s of the roll holding shaft portion 7, the contact member 11 can be moved from a position away from the side surface 7a to a position approaching the side surface 7a simply by loosening the male screw 21n of the shaft portion 21 from the screw hole 7h.

[0030] For example, as shown in FIGS. 1 and 2 , a base plate 24 is provided at the base end 6 of the shaft 5 (or the base end of the roll holding shaft 7). Specifically, the base plate 24 is provided so that a surface 24a located on the tip side of the roll holding shaft 7 (i.e., the surface facing the base end of the contact member 11) is perpendicular to the central axis 6s of the base end 6 of the shaft 5 (or the central axis 7s of the roll holding shaft 7). In addition, a spring 25 is provided between the base plate 24 and each contact member 11. Specifically, three springs 25 are provided so as to generate a biasing force that moves each contact member 11 from the base end toward the tip of the roll holding shaft 7. With this configuration, regardless of the vertical position of the contact member 11 relative to the central axis 7s of the roll holding shaft 7, simply by loosening the male screw 21n of the shaft 21 from the screw hole 7h, the biasing force of the spring 25 can move the contact member 11 from a state separated from the side surface 7a toward the side surface 7a.

[0031] The method for holding the spring 25 between the contact member 11 and the base plate 24 is not particularly limited as long as the spring force on the contact member 11 can be maintained even if the contact member 11 moves relative to the side surface 7a, and the spring 25 can be held so as not to come out from between the contact member 11 and the base plate 24.

[0032] Furthermore, although the size of the base plate 24 is not particularly limited, it is desirable that its outer diameter be larger than the outer diameter of the roll R attached to the roll holding mechanism 1 (or the outer diameter of the core C of the roll R). With such a size, the base plate 24 can determine the position of the roll R, that is, the position of the roll R in the axial direction of the shaft 5. Thus, if the rolls R have the same axial length, by installing the rolls R so that their ends contact the base plate 24, the rolls R can be installed so that their tips are in the same position. Furthermore, by installing a cylindrical spacer between the roll R and the base plate 24 and adjusting the axial length of the spacer, it is possible to keep the position of the tip of the roll R in the axial direction of the shaft 5 in the same position regardless of the axial length of the roll R.

[0033] <Operation of the roll holding mechanism 1> The operation of attaching and detaching the roll R using the roll holding mechanism 1 will now be described. In the following, a case will be described in which the three contact members 11 are constantly biased by the spring 25 to move from the base end of the roll holding shaft 7 toward the tip end, as shown in FIGS.

[0034] When attaching the roll R to the roll holding shaft 7 of the shaft 5 of the roll holding mechanism 1, the moving member 20 moves the three contact members 11 close to the side surface 7a. In this state, the outer diameters of the portions of the roll holding mechanism 1 where the core C of the roll R is attached and through which the core C of the roll R passes, including the outer diameter of the handle 22 and the outer diameter of the pressing member 23, are smaller than the inner diameter of the core C of the roll R. Therefore, by inserting the core C of the roll R from the tip of the roll holding shaft 7 of the shaft 5, the roll R can be attached to the roll holding shaft 7 of the shaft 5. In this state, a gap is formed between the inner surface of the core C of the roll R and the contact members 11 (see FIGS. 4(C) and 4(F)).

[0035] The outer diameter of the handle 22 and the outer diameter of the pressing member 23 do not have to be shorter than the inner diameter (diameter) of the core material C of the roll R held by the roll holding mechanism 1. In that case, when inserting the core material C of the roll R into the roll holding shaft portion 7 of the shaft portion 5, the handle 22 and the pressing member 23 of the moving member 20 are temporarily removed from the roll holding shaft portion 7 of the shaft portion 5. Then, after the roll R is attached to the roll holding shaft portion 7 of the shaft portion 5, the handle 22 and the pressing member 23 of the moving member 20 are attached to the roll holding shaft portion 7 of the shaft portion 5 again.

[0036] With the roll R attached to the roll holding shaft 7 of the shaft 5, the handle 22 is turned to screw the male screw 21n of the shaft 21 of the moving member 20 into the screw hole 7h. Then, the pressing member 23 of the moving member 20 moves toward the tip of the roll holding shaft 7, and eventually the pressing surface 23a of the pressing member 23 comes into contact with the tips of the three contact members 11 simultaneously (see FIGS. 4(C) and (F)).

[0037] When the male screw 21n of the shaft 21 is further screwed into the screw hole 7h at the tip of the roll holding shaft 7 from a state in which the pressing surface 23a of the pressing member 23 is in contact with the three contact members 11, the pressing member 23 moves the three contact members 11 from the tip to the base end of the roll holding shaft 7. Then, guided by the multiple guide shafts 19 provided in the guide wall pair 18t and the guide grooves 11g formed in the contact members 11, the three contact members 11 move in a direction away from the side surface 7a while moving from the tip to the base end of the roll holding shaft 7 (see FIGS. 4(B) and 4(E)).

[0038] Eventually, the outer surfaces 11b of the three contact members 11, more specifically, the corners 11e of the three contact members 11, simultaneously come into contact with the inner surface of the core material C of the roll R. If the core material C of the roll R is made of paper or the like, the corners 11e of the three contact members 11 will bite into the inner surface of the core material C of the roll R (see FIGS. 4(A) and 4(D)). Then, the roll R is firmly fixed to the roll holding shaft 7, i.e., the shaft 5, via the fixing part 10. Then, when the screwing of the male screw 21n is stopped, the fixing of the roll R to the roll holding mechanism 1 is completed.

[0039] In this state, if the roll R is rotated to unwind the sheet S from the roll R, the sheet S can be unwound stably.

[0040] Furthermore, when replacing the roll R, the handle 22 of the moving member 20 is turned to loosen the male screw 21n from the screw hole 7h. This causes the pressing surface 23a of the pressing member 23 to move from the base end toward the tip of the roll holding shaft 7, and the three contact members 11 also move from the base end toward the tip of the roll holding shaft 7 due to the biasing force of the spring 25. At this time, the three contact members 11 are guided by the multiple guide shafts 19 provided in the guide wall pair 18t and the guide grooves 11g formed in the contact members 11, and move in a direction approaching the side surface 7a while moving from the base end toward the tip of the roll holding shaft 7. This releases the roll R from its fixation to the roll holding shaft 7 (see FIGS. 4B and 4E).

[0041] Eventually, the three contact members 11 approach the side surface 7a (see FIGS. 4(C) and 4(F)), so that the roll R can be removed from the roll holding shaft portion 7 and a new roll R can be attached to the roll holding shaft portion 7. Thereafter, by repeating the above-described method, the new roll R can be fixed to the roll holding shaft portion 7.

[0042] As described above, by using the roll holding mechanism 1 of this embodiment, the roll R can be attached to and detached from the roll holding shaft 7 simply by moving the pressing member 23 of the moving member 20. Moreover, the roll holding mechanism 1 simply provides three holding members 16 on the roll holding shaft 7 of the shaft 5, and moves and positions the three contact members 11 using the guide walls 18 of the three holding members 16. Furthermore, because the movement of the three contact members 11 is also adjusted simply by the guide grooves 18g provided in the guide walls 18 and the guide shafts 19, the configuration of the roll holding mechanism 1 can be simplified.

[0043] In addition, the three contact members 11 have a pair of corners 11e, and when the three contact members 11 come into contact with the core material C of the roll R, the pair of corners 11e can be caused to bite into the core material C of the roll R, so that the roll R can be firmly fixed to the roll holding shaft portion 7 of the shaft portion 5.

[0044] <Regarding the Roller Holding Mechanism 1B of Another Embodiment> In the roll holding mechanism 1 described above, a guide groove 11g is provided in the contact member 11, and the movement of the contact member 11 is guided by a guide shaft 19 inserted into this guide groove 11g. The structure for guiding the movement of the contact member 11 may be configured as follows. Below, a roll holding mechanism 1B will be described, which is a modified version of the structure for guiding the movement of the contact member 11 from the roll holding mechanism 1 described above. In addition, in the roll holding mechanism 1B, the description of the same components as those of the roll holding mechanism 1 will be omitted as appropriate.

[0045] <Roll holding mechanism 1B> As shown in FIGS. 5 and 6, a roll holding mechanism 1B of another embodiment (hereinafter sometimes simply referred to as roll holding mechanism 1B) includes a shaft portion 5. This shaft portion 5 includes a base end portion 6 and a roll holding shaft portion 7 that continues from this base end portion 6. The base end portion 6 is supported by a bearing provided on a frame of the roll holding mechanism 1B (not shown) so that it can rotate about its central axis 6s. The roll holding shaft portion 7 has a regular hexagonal cross section and is provided with a fixed portion 10B. This fixed portion 10B includes three contact members 11B and a movement mechanism 15B that moves the three contact members 11B.

[0046] <Contact member 11B> As shown in Fig. 7, the three contact members 11B are plate-like (strip-like) members formed in the same shape (rectangular cross section, rectangular cross section in Fig. 7). These three contact members 11B are formed in substantially the same shape as the contact member 11 of the roll holding mechanism 1 described above. Unlike the contact member 11 of the roll holding mechanism 1, these contact members 11B are not provided with multiple guide grooves 11g, but are provided with a guide shaft 19B of a movement mechanism 15B. The guide shaft 19B of this movement mechanism 15B will be described later.

[0047] <Moving mechanism 15B> The fixed part 10B includes a moving mechanism 15B that moves the three contact members 11B. Specifically, the moving mechanism 15B moves the three contact members 11B toward or away from the side surface 7a in the radial direction (i.e., the direction perpendicular to the central axis 7s of the roll holding shaft part 7) while maintaining the outer surfaces 11b of the three contact members 11B parallel to the side surface 7a. The moving mechanism 15B includes three holding members 16B and a moving member 20.

[0048] <Holding member 16B> 7, the three holding members 16B of the moving mechanism 15B are respectively provided on the side surfaces 7b of the roll holding shaft portion 7 of the shaft portion 5. In other words, when the roll holding shaft portion 7 of the shaft portion 5 is viewed from the axial direction, the three holding members 16B are provided on the roll holding shaft portion 7 of the shaft portion 5 so that the contact members 11B and the holding members 16B are arranged alternately along the circumferential direction.

[0049] As shown in Figures 5 and 7, the holding member 16B is a member having substantially the same structure as the holding member 16 and is formed by bending a single long plate material. This holding member 16B includes a fixed wall 17B extending in the longitudinal direction (left-right direction in Figure 5) and a pair of guide walls 18B, 18B provided at both ends of the fixed wall 17B in the width direction and extending in the longitudinal direction (left-right direction in Figure 5). The fixed wall 17B is a portion fixed to the side surface 7b and is attached to the side surface 7b with its inner surface in contact with the side surface 7b. The pair of guide walls 18B, 18B are provided so that the angle θ2 (see Figure 7(A)) formed with the fixed wall 17B of the holding member 16B is 150°. In other words, when the fixed wall 17B is attached to the side surface 7b, the pair of guide walls 18B, 18B are arranged so that their surfaces intersect with the side surface 7a adjacent to the side surface 7b to which the fixed wall 17B is attached, and the guide walls 18B and the adjacent side surface 7a are perpendicular to each other. In other words, when the fixed wall 17B is attached to the side surface 7b, the pair of guide walls 18B, 18B are arranged so that the guide walls 18B of adjacent holding members 16B sandwich the adjacent side surface 7a. In other words, when the fixed wall 17B is attached to the side surface 7b, the pair of guide walls 18B, 18B are arranged so that the guide walls 18B of adjacent holding members 16B sandwich the contact member 11B provided on the adjacent side surface 7a. Hereinafter, the guide walls 18B of adjacent holding members 16B sandwiching the contact member 11B therebetween may be referred to as a guide wall pair 18t.

[0050] As shown in FIG. 5, the pair of guide walls 18B, 18B are provided with a plurality of guide grooves 18g (two guide grooves 18g in each guide wall 18B in FIG. 5). The plurality of guide grooves 18g are grooves that are parallel to one another and are inclined with respect to the direction of the central axis 7s of the roll holding shaft portion 7 of the shaft portion 5. Specifically, the guide grooves 18g are provided such that their axial direction becomes more distant from the side surface 7a (inclined upward in FIG. 5) as they extend from a first end (the end portion on the tip side of the roll holding shaft portion 7 (the end portion opposite the base end portion 6), the left end in FIG. 5; hereinafter, sometimes simply referred to as the "first end of the guide groove 18g") to a second end (the end portion on the base end side of the roll holding shaft portion 7 (the end portion on the base end portion 6 side), the right end in FIG. 5; hereinafter, sometimes simply referred to as the "second end of the guide groove 18g"). In other words, the guide groove 18g is formed so as to incline from the first end to the second end so that the second end is located farther away from the side surface 7a than the first end. Moreover, the guide grooves 18g provided in the guide wall pair 18t are provided at positions corresponding to one another. That is, when the guide wall pair 18t is viewed from the side (a direction parallel to the surface of the side surface 7a and perpendicular to the central axis 7s of the roll holding shaft portion 7), the guide grooves 18g are formed in each guide wall 18B so that the guide grooves 18g (corresponding guide grooves 18g) provided in the guide wall pair 18t overlap with one another.

[0051] The guide wall pair 18t has a plurality of guide grooves 18g, each of which has an end portion of a guide shaft 19B inserted therein (see FIG. 7B). More specifically, the guide grooves 18g are formed in the guide wall pair 18t, and the end portions of the guide shaft 19B are inserted therein so as to connect the corresponding guide grooves 18g. The guide shaft 19B is connected to the guide wall pair 18t so as to be movable along the axial direction of the guide grooves 18g but not in the axial direction. For example, the guide shaft 19B is formed so that its diameter is slightly smaller than the width of the guide grooves 18g, and a slip-out prevention member is attached to the end of the guide shaft. The portion of the guide shaft 19B between its ends is connected to the contact member 11B provided between the guide wall pair 18t. Specifically, the portion between both axial ends of the guide shaft 19B is coupled to the contact member 11B so that when the guide shaft 19B moves along the guide groove 18g, the contact member 11B moves together with the guide shaft 19B in the space between the pair of guide walls 18t. For example, as shown in FIG. 7(B), a through hole 11h having a circular cross section penetrating between both side surfaces 11c, 11c of the contact member 11B can be provided, and the portion between both axial ends of the guide shaft 19B can be coupled to the contact member 11B with the guide shaft 19B having a shaft diameter substantially the same as the inner diameter of the through hole 11h inserted into the through hole 11h. In this case, the guide shaft 19B may be fixed to the contact member 11B so as to be unable to move in the axial direction, or may simply be prevented from moving in the axial direction.

[0052] With the above-described configuration, the contact member 11B can move toward and away from the side surface 7a along the axial direction of the guide groove 18g, while its movement in the width direction is restricted by the pair of guide walls 18t.

[0053] As described above, the guide groove 18g is provided so as to incline from the first end toward the second end, and therefore, when approaching or moving away from the side surface 7a, the contact member 11 moves along the central axis direction of the roll holding shaft 7. More specifically, when approaching the side surface 7a, the contact member 11B moves from the base end toward the tip along the central axis direction of the roll holding shaft 7, and when moving away from the side surface 7a, the contact member 11B moves from the tip toward the base end along the central axis direction of the roll holding shaft 7.

[0054] Furthermore, as described above, the guide shaft 19B may be formed of a single shaft member, with the portion between both shaft ends connected to the contact member 11. However, the structure is not particularly limited as long as the contact member 11 can be moved along the guide groove 18g. For example, the guide shaft 19B may be a shaft-shaped member provided upright on each of a pair of side surfaces 11c, 11c of the contact member 11B (i.e., a protrusion formed on the pair of side surfaces 11c, 11c). Even in this case, if the tip of the shaft-shaped member formed on each side surface 11c is inserted into the guide groove 18g provided in the guide wall 18B facing each side surface 11c, the contact member 11B can be moved along the axial direction of the guide groove 18g while being guided by the guide shaft 19B.

[0055] Alternatively, the guide shaft 19B may be formed by a shaft member and a cylindrical member that is rotatable relative to the shaft member into which the shaft member is inserted. The cylindrical member of the guide shaft 19B may be fixed to the contact member 11B, and the shaft member may be rotatably inserted into the cylindrical member within the contact member. In this case, when the guide shaft 19B moves along the guide groove 18g, the shaft member rotates while sliding along the inner end of the guide groove 18g, which allows the guide shaft 19B to move smoothly along the guide groove 18g.

[0056] <Moving member 20> 5 and 6, a movable member 20 is provided at the tip of the roll holding shaft 7. This movable member 20 has the same structure and function as the movable member 20 of the roll holding mechanism 1. Therefore, by operating the movable member 20, the three contact members 11B can be simultaneously moved the same amount from the tip to the base end of the roll holding shaft 7, and simultaneously moved the same amount in a direction away from the side surface 7a (see FIG. 8), and the contact members 11B can be moved from a state away from the side surface 7a in a direction approaching the side surface 7a.

[0057] <Operation of the roll holding mechanism 1B> The operation of attaching and detaching the roll R using the roll holding mechanism 1B will now be described. In the following, as shown in FIGS. 5 and 6, a case will be described in which the three contact members 11B are biased by the spring 25 to constantly move the roll holding shaft portion 7 from the base end toward the tip end.

[0058] When attaching the roll R to the roll holding shaft 7 of the shaft 5 of the roll holding mechanism 1B, the three contact members 11B are brought close to the side surface 7a by the moving member 20. In this state, the roll R is attached to the roll holding shaft 7 of the shaft 5. In this state, there is a gap between the inner surface of the core C of the roll R and the contact members 11B (see Figures 8(C) and (F)).

[0059] From this state, the male screw 21n of the shaft 21 of the moving member 20 is screwed into the screw hole 7h. Then, the pressing member 23 of the moving member 20 moves toward the tip of the roll holding shaft 7, and eventually the pressing surface 23a of the pressing member 23 comes into contact with the tips of the three contact members 11B (see FIGS. 8(C) and (F)).

[0060] When the male screw 21n of the shaft 21 is further screwed into the screw hole 7h at the tip of the roll holding shaft 7 from a state in which the pressing surface 23a of the pressing member 23 is in contact with the three contact members 11B, the pressing member 23 moves the three contact members 11B from the tip toward the base end of the roll holding shaft 7. Then, guided by the multiple guide grooves 18g and the multiple guide shafts 19B provided in the guide wall pair 18t, the three contact members 11B move in a direction away from the side surface 7a while moving from the tip toward the base end of the roll holding shaft 7 (see FIGS. 8B and 8E).

[0061] Eventually, the outer surfaces 11b of the three contact members 11B, more specifically, the corners 11e of the three contact members 11B, come into contact with the inner surface of the core material C of the roll R, and if the core material C of the roll R is made of paper or the like, the corners 11e of the three contact members 11B will bite into the inner surface of the core material C of the roll R (see FIGS. 8(A) and 8(D)). Then, the roll R is firmly fixed to the roll holding shaft 7, i.e., the shaft 5, so that by stopping the screwing of the male screw 21n, the fixation of the roll R to the roll holding mechanism 1B is completed.

[0062] In this state, if the roll R is rotated to unwind the sheet S from the roll R, the sheet S can be unwound stably.

[0063] Furthermore, when replacing the roll R, the handle 22 of the moving member 20 is turned to loosen the male screw 21n from the screw hole 7h. This causes the pressing surface 23a of the pressing member 23 to move from the base end toward the tip of the roll holding shaft 7, and the three contact members 11B also move from the base end toward the tip of the roll holding shaft 7 due to the biasing force of the spring 25. At this time, guided by the multiple guide grooves 18g and multiple guide shafts 19 provided in the guide wall pair 18t, the three contact members 11B move in a direction approaching the side surface 7a while moving from the base end toward the tip of the roll holding shaft 7. This releases the roll R from its fixation to the roll holding shaft 7 (see FIGS. 8B and 8E).

[0064] Eventually, the three contact members 11B approach the side surface 7a (see FIGS. 8(C) and 8(F)). Then, the roll R can be removed from the roll holding shaft 7, and a new roll R can be attached to the roll holding shaft 7. Thereafter, by repeating the above-described method, the new roll R can be fixed to the roll holding shaft 7.

[0065] As described above, by using the roll holding mechanism 1B of this embodiment, the roll R can be attached to and detached from the roll holding shaft 7 simply by attaching and detaching the movable member 20 to and from the roll holding shaft 7. Moreover, the roll holding mechanism 1B simply provides three holding members 16B on the roll holding shaft 7 of the shaft 5, and the movement and positioning of the three contact members 11B is controlled by the guide walls 18B of the three holding members 16B. Furthermore, because the movement of the three contact members 11B is also adjusted by the guide grooves 18g provided in the guide walls 18B and the guide shafts 19B, the configuration of the roll holding mechanism 1B can be simplified.

[0066] In addition, the three contact members 11B have a pair of corners 11e, and when the three contact members 11B come into contact with the core material C of the roll R, the pair of corners 11e bite into the core material C of the roll R, so that the roll R can be firmly fixed to the roll holding shaft portion 7 of the shaft portion 5.

[0067] <Regarding the cross-sectional shape of the roll holding shaft portion 7> The cross-sectional shape of the roll holding shaft 7 is not limited to a regular hexagon, and may be any rotationally symmetric shape that has the same shape when rotated 120° about the central axis 7s. In other words, any cross-sectional shape may be used that allows the three contact members 11 of the fixing part 10 provided on the roll holding shaft 7 to be installed so as to be rotationally symmetric by 120°. For example, the cross-sectional shape of the roll holding shaft 7 may be an equilateral triangle or a regular nonagon, or may be a regular polygon having faces every 120° around the central axis.

[0068] The cross-sectional shape of the roll holding shaft 7 may be circular. Even if the roll holding shaft 7 has a circular cross-section, if the moving mechanism 15 has the three holding members 16 as described above, the three contact members 11 can be easily and accurately installed at intervals of 120° with respect to the central axis 7s (see Figures 3(C) and 7(C)).

[0069] <Regarding the shapes of the contact members 11 and 11B> The pair of side surfaces 11c, 11c of the contact members 11, 11B need only be formed so that when the contact members 11, 11B come into contact with the core material C of the roll R, the ridge line 11e formed between the contact members 11, 11B and the outer surface 11b can easily bite into the core material C of the roll R, and is not necessarily limited to the angle θ described above. In other words, the ridge line 11e needs only to be formed so that it can bite into the core material C of the roll R and suppress slippage (slippage around the central axis of the roll R) between the contact members 11, 11B and the core material C of the roll R. For example, the ridge line 11e may be chamfered as long as it can exhibit the aforementioned slippage suppression function.

[0070] <When the contact members 11, 11B are cantilevered> In the above-described example, the roll holding mechanism 1 of this embodiment has been described as having both ends of the guide shaft 19 fixed to a pair of guide walls 18t that sandwich the contact member 11. However, only one end of the guide shaft 19 may be fixed to one of the guide walls 18 of the pair of guide walls 18t. In other words, the guide shaft 19 may be configured to guide the movement of the contact member 11 in a cantilevered state. In this case, the holding member 16 may have only the fixed wall 17 and one guide wall 18. In other words, the holding member 16 may be provided with only a guide wall 18 that faces only one side surface 11c of the contact member 11. Similarly, in the roll holding mechanism 1B of this embodiment, both ends of the guide shaft 19B are inserted into the guide groove 18g formed in the pair of guide walls 18t that sandwich the contact member 11B. However, only one end of the guide shaft 19B may be inserted into the guide groove 18g formed in one of the guide walls 18B of the pair of guide walls 18t. In this case, the holding member 16B may have only the fixed wall 17B and one guide wall 18B. In other words, the holding member 16B may be provided with only a guide wall 18 that faces only one side surface 11c of the contact member 11B. [Industrial Applicability]

[0071] The roll holding mechanism of the present invention is suitable as a mechanism for holding a roll in a packaging device that unwinds a film or sheet from a roll on a production line or the like. [Explanation of symbols]

[0072] 1,1B Roll holding mechanism 5 Shaft 7 Roll holding shaft 7a side 7b side 10,10B Fixed part 11, 11B contact member 11b External surface 11g Guide groove 15,15B Moving mechanism 16, 16B Retaining member 17,17B Fixed wall 18,18B Guide wall 18g guide groove 19,19B Guide shaft 20 Moving parts 21 Shaft 23 Pressing member 23a Pressing surface R Roll C Core material

Claims

1. A roll holding mechanism that holds a roll and unwinds a sheet wound on the roll, a shaft portion that is rotatably provided and inserted into the core of the roll, and whose cross section is rotationally symmetrical with respect to the central axis; a fixing portion that fixes the roll to the shaft portion, The fixing portion is three contact members whose axial directions are parallel to the central axis of the shaft portion and which are provided at positions that are rotationally symmetrical with respect to the central axis of the shaft portion; a moving mechanism that moves the three contact members toward and away from the side surface of the shaft portion in a direction perpendicular to the axial direction of the shaft portion, The moving mechanism includes: The contact members are moved while maintaining the axial direction of the contact members parallel to the central axis of the shaft portion. A roll holding mechanism characterized by:

2. The moving mechanism includes: a holding member provided on a side surface of the shaft portion and having a guide wall parallel to the central axis direction of the shaft portion; a guide shaft that movably connects the guide wall of the holding member and the contact member, the guide shaft being provided on the guide wall of the holding member such that the axial direction thereof intersects with the central axis direction of the shaft portion, The contact member has: a guide groove is formed in a recessed portion of a side surface of the holding member facing the guide wall, the guide groove having an axial direction inclined with respect to a central axis direction of the shaft portion; The guide shaft is A guide groove is disposed in the guide groove so as to be movable along the axial direction of the guide groove.

2. The roll holding mechanism according to claim 1.

3. Three of the holding members are provided, Each holding member is a fixed wall connected to a side surface of the shaft portion; A pair of the guide walls is provided on the fixed wall, The three holding members are: The shaft portion is provided at a position that is rotationally symmetrical with respect to the central axis of the shaft portion, Three of the contact members are provided between the guide walls of adjacent holding members, The guide groove of the contact member is The guide wall is formed to penetrate between a pair of side surfaces facing each other and the guide wall of the adjacent holding member, The guide shaft is The contact member is inserted into the guide groove, and both ends of the contact member are fixed to the guide walls of the adjacent holding member.

3. The roll holding mechanism according to claim 2.

4. The moving mechanism includes: a holding member provided on a side surface of the shaft portion and having a guide wall parallel to the central axis direction of the shaft portion; a guide shaft that movably connects the guide wall of the holding member and the contact member, the guide shaft being provided so that its axial direction intersects with the central axial direction of the shaft portion, The guide shaft is the tip of the retaining member is provided on the contact member so as to protrude from a side surface of the contact member facing the guide wall of the retaining member, The tip of the shaft is inserted into a guide groove formed in the guide wall of the holding member, the axial direction of which is inclined with respect to the central axis of the shaft portion, so as to be movable along the axial direction of the guide groove.

2. The roll holding mechanism according to claim 1.

5. Three of the holding members are provided, Each holding member is a fixed wall connected to a side surface of the shaft portion; A pair of the guide walls is provided on the fixed wall, The three holding members are: The shaft portion is provided at a position that is rotationally symmetrical with respect to the central axis of the shaft portion, Three of the contact members are provided between the guide walls of the adjacent holding members, The guide shaft is Both ends of the support member are movably inserted into the guide grooves formed in the guide walls of the adjacent support members.

5. The roll holding mechanism according to claim 4.

6. The guide groove provided in the contact member or the guide groove provided in the guide wall of the holding member is The shaft portion is inclined from one end to the other end so as to move away from the side surface of the shaft portion, The moving mechanism includes: a moving member that moves toward and away from one end surface of the shaft portion along the central axis direction of the shaft portion, The moving member is When the contact member moves from one end of the shaft portion toward the other end, the contact member comes into contact with the edges of the three contact members on the one end side of the shaft portion, thereby moving the three contact members toward the other end side of the shaft portion.

6. The roll holding mechanism according to claim 2, wherein the roll holding mechanism is a roller.

7. The moving member is The distance from the central axis of the shaft portion to the outer edge of the moving member in a direction perpendicular to the central axis direction of the shaft portion is shorter than the distance from the central axis of the shaft portion to the outer edge of the contact member in a direction perpendicular to the central axis direction of the shaft portion when the three contact members are brought close to the side surface of the shaft portion.

7. The roll holding mechanism according to claim 6.

8. The cross section of the shaft member is a regular hexagon.

2. The roll holding mechanism according to claim 1.

9. The contact member is an outer surface located on the opposite side of the shaft portion and parallel to the central axis direction of the shaft portion; a pair of side surfaces parallel to the central axis direction of the shaft portion and intersecting the outer surface; Corners are formed between the pair of side surfaces and the outer surface.

2. The roll holding mechanism according to claim 1.

10. A roll holding device that holds a roll and unwinds the sheet, A roll holding mechanism according to claim 1 is provided. A roll holding device characterized by:

Images