Patent Publication Number: US-10329111-B2

Title: Sheet delivery system and sheet delivery method using same

Description:
TECHNICAL FIELD 
     The present invention relates to a system and a method for continuously delivering a sheet. 
     BACKGROUND ART 
     Conventionally, apparatuses are known for continuously delivering a sheet from an original material roll formed by winding the sheet. 
     When a remaining sheet amount of the original material roll becomes small in an apparatus of this type, for example, a joining operation of sheets such as that shown in  FIG. 29  to  FIG. 32  is performed. 
     Specifically, in order to perform the joining operation, as shown in  FIG. 29 , an original material roll (hereinafter, referred to as a standby-side original material roll) R 2  which stands by for delivery of a sheet W is installed in advance adjacently to an original material roll (hereinafter, referred to as a delivery-side original material roll) R 1  which delivers the sheet W. 
     As shown in  FIG. 30 , when a remaining amount of the sheet W of the delivery-side original material roll becomes small, an end section of the sheet W is retrieved from the standby-side original material roll R 2  and an adhesive (for example, a tape T) is affixed to the end section of the sheet W. 
     Next, as shown in  FIG. 31 , using the tape T, the end section of the sheet W of the standby-side original material roll R 2  is connected to an intermediate section of the sheet W of the delivery-side original material roll R 1  and the sheet W of the delivery-side original material roll R 1  is cut at an upstream position (a position denoted by a triangle in  FIG. 31 ) relative to the tape T. 
     Accordingly, as shown in  FIG. 32 , tension applied to the sheet W on a downstream side of both original material rolls R 1  and R 2  is applied via the tape T to the sheet W of the standby-side original material roll R 2 , and the sheet W is delivered from the standby-side original material roll R 2 . In other words, the standby-side original material roll R 2  performs a role of a next delivery-side original material roll R 1 . 
     As an apparatus for automatically performing the joining operation described above, for example, an apparatus described in Patent Literature 1 is known. 
     The apparatus described in Patent Literature 1 includes: a roll holding unit which holds a delivery-side original material roll and a standby-side original material roll; a joining unit which joins a sheet of the standby-side original material roll to a sheet of the delivery-side original material roll; and an XY mobile robot which retrieves an end section of the sheet of the standby-side original material roll and which guides the end section to a suction holding unit. 
     The joining unit includes a suction holding member configured to hold the end section of the sheet of the standby-side original material roll by suctioning the end section. 
     An adhesive tape is attached to the end section of the sheet held on the suction holding member, and the end section of the sheet is joined to an intermediate section of the sheet of the delivery-side original material roll by an adhesive force of the adhesive tape. 
     Patent Literature 1 does not clarify how the end section of the sheet held by the suction holding member is joined to the sheet of the delivery-side original material roll. 
     For example, the end section of the sheet held by the suction holding member is conceivably joined to the sheet of the delivery-side original material roll by moving the suction holding member toward the sheet of the delivery-side original material roll. 
     When the suction holding member moves in a direction approaching the standby-side original material roll during a movement of the suction holding member toward the sheet of the delivery-side original material roll, slack is created on a sheet between the suction holding member and the standby-side original material roll and a delivery speed of the sheet after a joining operation may change. 
     Therefore, the suction holding unit must be moved with respect to the delivery-side original material sheet so that slack is not created on the sheet between the suction holding member and the standby-side original material roll. 
     However, in this case, there is a risk that tension created on the sheet between the suction holding member and the standby-side original material roll changes a holding position of a tip section of the sheet with respect to the suction holding member, and the end section of the sheet can no longer be accurately joined to a sheet of the delivery-side original material roll. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: Japanese Unexamined Patent Publication No. H7-101602 
     SUMMARY OF INVENTION 
     An object of the present invention is to provide a sheet delivery system capable of preventing a holding position of a sheet with respect to a suction holding member from changing during a movement of the suction holding member, and a sheet delivery method using the sheet delivery system. 
     In order to solve the problem described above, the present invention provides a sheet delivery system for continuously delivering a sheet, the sheet delivery system including: a roll holding unit which holds a plurality of original material rolls, each formed by winding a sheet, in a state where delivery of the sheet is allowed; a joining unit which joins, to an intermediate section of a sheet being delivered from a delivery-side original material roll among the plurality of original material rolls held by the roll holding unit, an end section of a sheet of a standby-side original material roll that is a roll other than the delivery-side original material roll among the plurality of original material rolls held by the roll holding unit; an end section conveying apparatus which retrieves the end section of the sheet from the standby-side original material roll and which conveys the end section of the sheet to the joining unit; and a controller which controls an operation of the joining unit, wherein the joining unit includes: a suction holding member having a suction surface configured to suction the end section of the sheet of the standby-side original material roll conveyed by the end section conveying apparatus; a moving mechanism configured to move the suction surface of the suction holding member toward the intermediate section of the sheet of the delivery-side original material roll along a path set in advance so that tension is applied to a sheet between the standby-side original material roll and the suction holding member; and a regulating mechanism that is configured to switch between a regulated state in which a movement of the end section of the sheet with respect to the suction holding member due to the tension is regulated and an allowable state in which the movement of the end section of the sheet with respect to the suction holding member is allowed, and the controller switches the regulating mechanism to the regulated state during the movement of the suction surface toward the intermediate section of the sheet of the delivery-side original material roll. 
     In addition, the present invention provides a sheet delivery method using the sheet delivery system described above, the sheet delivery method including: a delivery step of delivering a sheet from the delivery-side original material roll; a conveying step of retrieving an end section of a sheet of the standby-side original material roll and conveying the end section of the sheet to the suction holding member of the joining unit using the end section conveying apparatus when a remaining sheet amount of the delivery-side original material roll falls below a remaining amount set in advance by the delivery step; and a joining step of joining the end section of the sheet of the standby-side original material roll to an intermediate section of the sheet of the delivery-side original material roll by moving the suction surface of the suction holding member toward the intermediate section of the sheet of the delivery-side original material roll using the moving mechanism while regulating a movement of the end section of the sheet with respect to the suction holding member using the regulating mechanism. 
     According to the present invention, a holding position of a sheet with respect to a suction holding member can be prevented from changing during a movement of the suction holding member. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a front view showing an overall configuration of a sheet delivery system according to a first embodiment of the present invention. 
         FIG. 2  is a side view of the sheet delivery system shown in  FIG. 1 . 
         FIG. 3  is a schematic diagram showing an enlargement of a part of an operation robot shown in  FIG. 1 . 
         FIG. 4  is a sectional view taken along line IV-IV in  FIG. 3 . 
         FIG. 5  is a partially sectional plan view showing an enlargement of an end section retrieving unit shown in  FIG. 1 . 
         FIG. 6  is a sectional view taken along line VI-VI in  FIG. 5 . 
         FIG. 7  is a sectional view taken along line VII-VII in  FIG. 5 . 
         FIG. 8  is a front view showing an enlargement of a joining unit shown in  FIG. 1 . 
         FIG. 9  is a sectional view taken along line IX-IX in  FIG. 8  and shows a state where a tape affixing unit is moved to a retreated position. 
         FIG. 10  is a sectional view taken along line X-X in  FIG. 9 . 
         FIG. 11  is a sectional view taken along line XI-XI in  FIG. 10 . 
         FIG. 12  corresponds to a sectional view taken along line IX-IX in  FIG. 8  and shows a state where a tape affixing unit is moved to a tape attaching position. 
         FIG. 13  is a sectional view taken along line XIII-XIII in  FIG. 9 . 
         FIG. 14  is a block diagram showing an electric configuration of the sheet delivery system shown in  FIG. 1 . 
         FIG. 15  is a flow chart showing a first half portion of a process executed by a controller shown in  FIG. 14 . 
         FIG. 16  is a flow chart showing a second half portion of the process executed by the controller shown in  FIG. 14 . 
         FIG. 17  is a schematic diagram for explaining a method of calculating an amount of variation of a position of an end section of a sheet by the controller shown in  FIG. 14 . 
         FIG. 18  is a side sectional view showing an operation of an operation robot in a state where a sheet is grasped at an end section retrieving unit. 
         FIG. 19  is a front view showing an operation of an operation robot and showing a trajectory of movement of a sheet by a hand. 
         FIG. 20  is a front view showing an operation of an operation robot in a state where a sheet is guided to a suction holding member. 
         FIG. 21  is a front view showing an operation of an operation robot in a state where a sheet is placed on a suction holding member. 
         FIG. 22  is a front view showing an operation of an operation robot in a state where a sheet on a suction holding member is smoothed and a tip section of the sheet is pushed inward. 
         FIG. 23  is a front view showing an operation of a joining unit in a state where a tip section of a sheet is pressed by a pressing member. 
         FIG. 24  is a front view showing an operation of a joining unit in a state where a standby-side joining mechanism is moved toward a delivery-side joining mechanism. 
         FIG. 25  is a front view showing an operation of a joining unit in a state where a sheet of a delivery-side original material roll is joined to a sheet of a standby-side original material roll via a tape. 
         FIG. 26  is a front view showing an operation of a joining unit in a state where a sheet of a delivery-side original material roll is to be cut. 
         FIG. 27  is a front view showing an operation of a joining unit in a state where delivery of a sheet of a standby-side original material roll is started. 
         FIG. 28  is a front view showing an overall configuration of a sheet delivery system according to a second embodiment of the present invention. 
         FIG. 29  is a conceptual diagram for explaining a joining operation and shows a state where a sheet is being delivered from a delivery-side original material roll. 
         FIG. 30  is a conceptual diagram for explaining a joining operation and shows a state where a tape is affixed to a tip section of a sheet of a standby-side original material roll. 
         FIG. 31  is a conceptual diagram for explaining a joining operation and shows a state where a sheet of a delivery-side original material roll is to be cut after a midway section of the sheet of the delivery-side original material roll is joined to a tip section of a sheet of the standby-side original material roll. 
         FIG. 32  is a conceptual diagram for explaining a joining operation and shows a state where delivery of a sheet of a standby-side original material roll is started. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It is to be understood that the following embodiments are merely examples embodying the present invention and are not intended to limit the technical scope of the present invention. 
     &lt;First Embodiment&gt; 
     Referring to  FIG. 1  and  FIG. 2 , a sheet delivery system  1  is configured to continuously deliver a sheet W. 
     Specifically, the sheet delivery system  1  includes: a sheet delivery apparatus  2  which holds original material rolls R 1  and R 2 , each formed by winding the sheet W and which continuously delivers the sheet W of the original material rolls R 1  and R 2 ; an operation robot (an end section conveying apparatus)  3  which, when a remaining amount of the sheet W of one original material roll (for example, the original material roll R 1 ) becomes small in the sheet delivery apparatus  2 , retrieves the sheet W of the other original material roll (for example, the original material roll R 2 ) and conveys the sheet W to a joining unit  8  of the sheet delivery apparatus  2 ; and a controller  70  (refer to  FIG. 14 ) which controls operations of the sheet delivery apparatus  2  and the operation robot  3 . 
     The sheet delivery apparatus  2  includes: a roll holding unit  5  which holds the original material rolls R 1  and R 2  in a state where delivery of the sheet W is allowed; a guiding unit  6  which guides the sheets of the original material rolls R 1  and R 2  held by the roll holding unit  5  along a path set in advance; end section retrieving units  7 A and  7 B which respectively retrieves the sheets of the original material rolls R 1  and R 2  held by the roll holding unit  5 ; a joining unit  8  which joins the sheet of the original material roll R 1  and the sheet of the original material roll R 2  to each other; tape affixing units  9 A and  9 B which respectively affix a tape T (refer to  FIG. 23 ) to the sheets of the original material rolls R 1  and R 2 ; and a supporting member  4  which supports these units. 
     The supporting member  4  includes: a bottom plate  10  arranged parallel to an installation surface; four supporting columns  11  erected on the bottom plate  10 ; and a supporting plate  12  fixed to a side surface of the supporting columns  11 . 
     The four supporting columns  11  are arranged in a single row. 
     The supporting plate  12  includes 18 supporting plate pieces  12   a , and an attachment surface for attaching the configuration described above is formed by main surfaces of the supporting plate pieces  12   a . Specifically, the 18 supporting plate pieces  12   a  are detachably attached to two supporting columns  11  adjacent to each other so as to span the two supporting columns  11 . In addition, six supporting plate pieces  12   a  aligned in a height direction of the supporting columns  11  are attached to two supporting columns  11  adjacent to each other. Furthermore, the 18 supporting plate pieces  12   a  are fixed to the supporting columns  11  so that main surfaces of the 18 supporting plate pieces  12   a  are arranged on a same plane. 
     In the following description, a direction in which the four supporting columns  11  are lined up is assumed to be an X direction, a direction perpendicular to the main surfaces of the supporting plate pieces  12   a  is assumed to be a Y direction, and the height direction of the supporting columns  11  is assumed to be a Z direction. 
     Moreover, each of the supporting plate pieces  12   a  holds the components of the sheet delivery apparatus  2  so that a part of the components can be readily replaced. 
     For example, an uppermost supporting plate piece  12   a  provided in a rightmost column in  FIG. 1  holds the second end section retrieving unit  7 B to be described later. In addition, a third-from-top supporting plate piece  12   a  in the rightmost column holds the second roll holding unit  5 B to be described later. Furthermore, a fourth-from-top supporting plate piece  12   a  in the rightmost column holds the tape affixing unit  9 B to be described later. By detaching these supporting plate pieces  12   a  from the supporting column  11  and attaching supporting plate pieces  12   a  holding other components, components can be readily replaced. 
     The roll holding unit  5  includes: a first roll holding unit  5 A which holds the original material roll R 1 ; and a second roll holding unit  5 B which holds the original material roll R 2 . Moreover, since both roll holding units  5 A and  5 B have configurations symmetrical in the X direction, only the second roll holding unit  5 B will be described and a description of the first roll holding unit  5 A will be omitted. 
     The second roll holding unit  5 B includes: a holding shaft  14  which supports the original material roll R 2  in a state where the holding shaft  14  penetrates a center of the original material roll R 2 ; a roll driving motor  15  which rotationally drives the holding shaft  14 ; and a remaining sheet amount detector  16  configured to detect a remaining amount of the sheet W of the original material roll R 2 . 
     The holding shaft  14  penetrates the supporting plate  12  in the Y direction and is further fixed to the supporting plate  12  in a state where the holding shaft  14  is rotatable around an axis along the Y direction with respect to the supporting plate  12 . 
     The roll driving motor  15  corresponds to an original material roll driving unit which rotationally drives the original material rolls R 1  and R 2  around central axes thereof. Specifically, the roll driving motor  15  is attached to an end section of the holding shaft  14  on an opposite side to an end section which supports the original material roll R 2 . 
     The remaining sheet amount detector  16  is attached to the supporting plate  12  at a position separated from the original material roll R 2  that is supported by the holding shaft  14 . In addition, the remaining sheet amount detector  16  includes a sensor configured to detect a distance from the remaining sheet amount detector  16  to an outer peripheral surface of the original material roll R 2 . The controller  70  to be described later calculates radius of the original material rolls R 1  and R 2  or, in other words, a remaining sheet amount based on a result of detection by the remaining sheet amount detector  16  and a position of the holding shaft  14 . 
     The guiding unit  6  includes: a plurality of support rollers  6   a  to  6   g  which support the sheet W delivered from the original material rolls R 1  and R 2  along a prescribed path; and a sheet storage mechanism  6   h  configured to temporarily store a prescribed amount of the sheet W delivered from the original material rolls R 1  and R 2 . 
     Among the support rollers  6   a  to  6   g , the support rollers  6   c  to  6   g  are commonly used for the sheets W of both original material rolls R 1  and R 2 . On the other hand, the support roller  6   a  is used to guide the sheet W of the first original material roll R 1  to the joining unit  8  to be described later. In addition, the support roller  6   b  is used to guide the sheet W of the second original material roll R 2  to the joining unit  8 . 
     The sheet storage mechanism  6   h  includes: an upper roller group  6 A constituted by a plurality of rollers; a lower roller group  6 B constituted by a plurality of rollers; and a moving mechanism (not shown) configured to move the roller groups  6 A and  6 B so that the roller groups  6 A and  6 B relatively approach each other or separate from each other. By providing the sheet W between the upper roller group  6 A and the lower roller group  6 B in a state where the upper roller group  6 A and the lower roller group  6 B are separated from each other and bringing the upper roller group  6 A and the lower roller group  6 B close to each other in this state, the sheet W can be delivered to downstream sides of both roller groups  6 A and  6 B in a state where rotations of the original material rolls R 1  and R 2  are stopped. Due to the sheet storage mechanism  6   h , a joining operation of the sheet W to be described later can be performed in a state where rotations of both original material rolls R 1  and R 2  are stopped. 
     The first and second end section retrieving units  7 A and  7 B are attached to the supporting plate  12  at a position which is above both holding shafts  14  of the roll holding unit  5  and which is between both holding shafts  14  in the X direction. Moreover, since the first and second end section retrieving units  7 A and  7 B have configurations symmetrical in the X direction, only the second end section retrieving unit  7 B will be described and a description of the first end section retrieving unit  7 A will be omitted. 
     Referring to  FIG. 1 ,  FIG. 2 , and  FIG. 5 , the second end section retrieving unit  7 B includes: a rotary shaft  17  extending in the Y direction from the supporting plate  12 ; a pair of arms  18   a  and  18   b  respectively having a base end section fixed to the rotary shaft  17 ; a supporting shaft  19  provided so as to span between respective tip sections of the arms  18   a  and  18   b ; a plurality of suction rollers  21  rotatably attached to an outer peripheral surface of the supporting shaft  19  via a plurality of bearings  20 ; a rotary cylinder  22  which rotationally drives both arms  18   a  and  18   b ; a rotary valve  24  which controls extension/contraction operations of the rotary cylinder  22 ; a rotational angle detector  25  which detects a rotational angle of the rotary shaft  17 ; a suction valve  26  connected to the supporting shaft  19 ; and an end section detector  27  attached to the supporting shaft  19 . 
     The rotary shaft  17  penetrates the supporting plate  12  in the Y direction and is further fixed to the supporting plate  12  in a state where the rotary shaft  17  is rotatable around an axis along the Y direction with respect to the supporting plate  12 . A rotational angle of the rotary shaft  17  is detected by the rotational angle detector  25  attached to a base end section of the rotary shaft  17 . 
     The arms  18   a  and  18   b  correspond to rotary supporting members which are rotatable with respect to the roll holding unit  5  (the supporting plate  12 ) around the rotary shaft  17  being parallel to a central axis (the holding shaft  14 ) of the original material roll R 2  so that a distance between the supporting shaft  19 , to be described later, and the central axis of the original material roll R 2  is adjustable. 
     Specifically, the arms  18   a  and  18   b  rotate around an axis of the rotary shaft  17  in accordance with extension/contraction operations of the rotary cylinder  22 . A base end section (a head-side end section) of the rotary cylinder  22  is attached by a shaft  22   b  to the supporting plate  12  in a state where the base end section is rotatable with respect to the supporting plate  12  around an axis along the Y direction. On the other hand, a distal end section (a rod-side end section) of the rotary cylinder  22  is attached by a shaft  22   a  to intermediate sections of both arms  18   a  and  18   b  in a state where the distal end section is rotatable with respect to both arms  18   a  and  18   b  around an axis along the Y direction. The rotary valve  24  is configured to control supply of air to the rotary cylinder  22  and discharge of air from the rotary cylinder  22 . 
     The supporting shaft  19  is a hollow shaft which internally includes a suction chamber  19   a . A distal end section of the supporting shaft  19  includes a bottom wall for closing the suction chamber  19   a . On the other hand, a base end section of the supporting shaft  19  is connected to a suction source (not shown) via the suction valve  26 . Therefore, by opening the suction valve  26 , air inside the suction chamber  19   a  is sucked out by the suction source. 
     In addition, as shown in  FIG. 6 , the supporting shaft  19  includes a through-hole  19   b  which penetrates an outer peripheral wall thereof. The plurality of bearings  20  are provided at positions separated from the through-hole  19   b  in an axial direction (Y direction) of the supporting shaft  19 , and the suction rollers  21  are provided so as to span between adjacent bearings  20 . A suction roller  21  includes a through-hole  21   a  which penetrates the suction roller  21  in a radial direction thereof. Accordingly, the suction chamber  19   a  is opened to the outside in the radial direction of the suction roller  21  through spaces between adjacent bearings  20  and the through-hole  21   a . Therefore, by bringing the sheet W into contact with an outer peripheral surface of the suction roller  21  in a state where the suction valve  26  is opened, the sheet W is suctioned by the suction roller  21 . 
     As described above, the plurality of suction rollers  21  are attached to the supporting shaft  19  in a state where the suction rollers  21  are rotatable around the axis of the supporting shaft  19  and are arranged separated from each other in a direction (Y direction) which is parallel to the axis. In addition, the suction rollers  21  are configured to come into rolling contact with the outer peripheral surface of the original material roll R 2  in accordance with the original material roll R 2  being rotationally driven, and include an outer peripheral surface configured to suction an end section of the sheet W in order to separate the end section of the sheet W from the original material roll R 2 . 
     The end section detector  27  is configured to detect a position of the end section of the sheet W of the original material roll R 2  having been separated by the suction roller  21 . Specifically, as shown in  FIG. 7 , the end section detector  27  is attached to the supporting shaft  19  at a position which is inside in a radial direction of outer peripheral surfaces of the two suction rollers  21  and which is between the two suction rollers  21 . 
     The controller  70 , to be described later, stops rotational driving of the original material roll R 2  when the end section of the sheet W of the original material roll R 2  is detected by the end section detector  27  and, in this state, the end section of the sheet W is grasped by a hand  60  of the operation robot  3 . In other words, a position of the end section of the sheet W having been suctioned by the suction roller  21  and detected by the end section detector  27  corresponds to a sheet retrieval position for retrieving the sheet W from the original material roll R 2 . A sheet retrieval position is similarly set on the original material roll R 2  or, in other words, the first end section retrieving unit  7 A. 
     Referring to  FIG. 1  and  FIG. 2 , the joining unit  8  is for joining, to an intermediate section of the sheet W being delivered from a delivery-side original material roll among the original material rolls R 1  and R 2  held by the roll holding unit  5 , an end section of the sheet W of a standby-side original material roll that is a roll other than the delivery-side original material roll among the original material rolls R 1  and R 2  held by the roll holding unit  5 . While each of the original material rolls R 1  and R 2  held by the roll holding unit  5  sequentially switches to a delivery-side original material roll and a standby-side original material roll in the sheet delivery system  1 , in the following description, the original material roll R 1  is assumed to be the delivery-side original material roll and the original material roll R 2  is assumed to be the standby-side original material roll. 
     Referring to  FIG. 8  to  FIG. 10 , the joining unit  8  includes: a shaft supporting plate  23  which opposes the supporting plate  12  and which supports, between the shaft supporting plate  23  and the supporting plate  12 , two shafts  28   a  extending in the Y direction; joining mechanisms  28 A and  28 B attached to the supporting plate  12  respectively in a state where the joining mechanisms  28 A and  28 B are rotatable around the shafts  28   a ; a rotary cylinder  29 A which rotationally drives the joining mechanism  28 A; a rotary cylinder  29 B which rotationally drives the joining mechanism  28 B; a rotary valve  30 A which controls driving of the rotary cylinder  29 A; and a rotary valve  30 B which controls driving of the rotary cylinder  29 B. 
     The joining mechanisms  28 A and  28 B are attached to the supporting plate  12  in a state where the joining mechanisms  28 A and  28 B are rotatable around the shaft  28   a  between a delivery position (a position of the joining mechanism  28 A shown in  FIG. 8 ) for delivering the sheet W along the guiding unit  6  in accordance with extension/contraction operations of the rotary cylinders  29 A and  29 B and a mounting position (a position of the joining mechanism  28 B in  FIG. 8 ) for mounting the end section of the sheet W to be joined to the intermediate section of the sheet W being delivered. 
     The rotary cylinders  29 A and  29 B include: a cylinder main body attached to the supporting plate  12  in a state where the cylinder main body is rotatable around a shaft  29   a  extending in the Y direction; and a rod attached to the joining mechanisms  28 A and  28 B (opposing plates  31   a  and  31   b  to be described later) in a state where the rod is rotatable around a shaft  29   b  extending in the Y direction. The joining mechanisms  28 A and  28 B rotate to the mounting position as the rod contracts with respect to the cylinder main body of the rotary cylinders  29 A and  29 B, and rotate to the delivery position as the rod extends from the cylinder main body of the rotary cylinders  29 A and  29 B. 
     The rotary valves  30 A and  30 B control extension/contraction operations of the rotary cylinders  29 A and  29 B by controlling supply of air to the rotary cylinders  29 A and  29 B and discharge of air from the rotary cylinders  29 A and  29 B. 
     Moreover, since the joining mechanisms  28 A and  28 B have configurations symmetrical in the X direction, the configuration of the joining mechanism  28 B will be mainly described. 
     The joining mechanism  28 B includes: opposing plates  31   a  and  31   b  which oppose each other in the Y direction; and a holding roller  32 , a suction holding member  33 , a pressing member  34 , a cutting blade  35 , a pressing blade  36 , a push-in cylinder  37 , a cutting cylinder  38 , and a sheet pressing cylinder  39  provided between the opposing plates  31   a  and  31   b.    
     The holding roller  32  is attached to the opposing plates  31   a  and  31   b  in a state where the holding roller  32  is rotatable around a rotary shaft  32   a  extending in the Y direction between both opposing plates  31   a  and  31   b . In addition, the holding roller  32  is for supporting the sheet W between the support roller  6   b  and the support roller  6   c  (the holding roller  32  of the joining mechanism  28 A holds the sheet W between the support roller  6   a  and the support roller  6   c ). Specifically, in the joining mechanism  28 B having rotated to the mounting position, an upper end of the holding roller  32  of the joining mechanism  28 B is arranged at an approximately same height position as a lower end of the support roller  6   b , and the sheet W guided to the holding roller  32  from the support roller  6   b  is arranged approximately horizontally. On the other hand, in the joining mechanism  28 A having rotated to the delivery position, the holding roller  32  of the joining mechanism  28 A is arranged above the support roller  6   a . Accordingly, the sheet W is guided upward from the support roller  6   a  toward the holding roller  32  and guided downward from the holding roller  32  toward the support roller  6   c.    
     Referring to  FIG. 10  and  FIG. 11 , the suction holding member  33  includes a suction surface  33   d  configured to suction the end section of the sheet W. Specifically, the suction holding member  33  includes: a decompression chamber  33   a  provided inside the suction holding member  33 ; a through-hole  33   b  which penetrates a side wall including a suction surface  33   d  and which opens the decompression chamber  33   a  to the outside of the decompression chamber  33   a ; and a pipe  33   c  which is provided on a side wall on an opposite side to the suction surface  33   d  and which communicates with the decompression chamber  33   a . The pipe  33   c  is connected to a suction source (not shown) via a suction valve  43 . Therefore, by opening the suction valve  43 , air inside the decompression chamber  33   a  is sucked out to enable the suction surface  33   d  to suction the sheet W. 
     In this case, the suction holding member  33  is provided between the shaft  28   a  and the holding roller  32 . In addition, the suction holding member  33  is attached to the opposing plates  31   a  and  31   b  so that the suction surface  33   d  is arranged approximately parallel to a YZ plane (refer to  FIG. 24 ) in a state where the joining mechanism  28 B is rotated to the delivery position and that the suction surface  33   d  is arranged approximately parallel to an XY plane in a state where the joining mechanism  28 B is rotated to the mounting position. Therefore, when the sheet W of the original material roll R 2  is placed on the suction surface  33   d  in a state where the joining mechanism  28 B is rotated to the mounting position as shown in  FIG. 23  and, in this state, the joining mechanism  28 B is rotated to the delivery position as shown in  FIG. 24 , the suction surface  33   d  of the suction holding member  33  moves toward the intermediate section (the joining mechanism  28 A) of the sheet W of the delivery-side original material roll R 1  while applying tension to the sheet W between the original material roll R 2  and the suction holding member  33 . In other words, the shaft  28   a , the opposing plates  31   a  and  31   b , the rotary cylinders  29 A and  29 B, and the rotary valves  30 A and  30 B correspond to a moving mechanism in which the suction surface  33   d  is movable toward the intermediate section of the delivery-side original material roll R 1  or R 2  along a path set in advance so that tension is applied to the sheet W between the original material rolls R 1  and R 2  and the suction holding member  33 . 
     Furthermore, as indicated by a solid line and a chain double-dashed line in  FIG. 10 , the suction holding member  33  is attached to the opposing plates  31   a  and  31   b  so that the suction surface  33   d  can move reciprocally in a direction perpendicular to the suction surface  33   d  in accordance with extension/contraction operations of the push-in cylinder  37 . Specifically, the push-in cylinder  37  includes: a cylinder main body fixed to both opposing plates  31   a  and  31   b ; and a rod which is extendable/contractible with respect to the cylinder main body, and a tip section of the rod is fixed to the suction holding member  33 . A push-in valve  40  which controls extension/contraction operations of the push-in cylinder  37  by controlling supply of air to the push-in cylinder  37  and discharge of air from the push-in cylinder  37  is connected to the push-in cylinder  37 . 
     The pressing member  34  includes a pressing surface  34   b  which presses a tip section of the sheet W between the pressing member  34  and a pressed surface  33   e  of the suction holding member  33 . In this case, the pressed surface  33   e  is a side surface of the suction holding member  33  extending from an edge of the suction surface  33   d  in an opposite direction to a direction to which the suction surface  33   d  faces. 
     Specifically, the pressing member  34  is attached to the opposing plates  31   a  and  31   b  so as to be rotatable with respect to the opposing plates  31   a  and  31   b  around the shaft  28   a  between a restricted position (a position indicated by the solid line in  FIG. 10 ) at which the tip section of the sheet W is sandwiched between the pressed surface  33   e  and the pressing surface  34   b  and an allowable position (a position indicated by the chain double-dashed line in FIG.  10 ) at which the pressing surface  34   b  is separated from the pressed surface  33   e  in accordance with extension/contraction operations of the sheet pressing cylinder  39 . The sheet pressing cylinder  39  includes: a cylinder main body attached to the opposing plates  31   a  and  31   b  in a state where the cylinder main body is rotatable around a shaft  39   a  extending in the Y direction; and a rod which is extendable/contractible with respect to the cylinder main body and which is attached to the pressing member  34  in a state where the rod is rotatable around a shaft  39   b  extending in the Y direction. A sheet pressing valve  42  which controls extension/contraction operations of the sheet pressing cylinder  39  by controlling supply of air to the sheet pressing cylinder  39  and discharge of air from the sheet pressing cylinder  39  is connected to the sheet pressing cylinder  39 . 
     In other words, the opposing plates  31   a  and  31   b , the shafts  39   a  and  39   b , the sheet pressing cylinder  39 , and the sheet pressing valve  42  correspond to a pressing driving mechanism which drives the pressing member  34  so that the pressing surface  34   b  approaches and retreats from the pressed surface  33   e . In addition, the pressing driving mechanism corresponds to a regulating mechanism that is configured to switch between a regulated state (a restricted position) in which a movement of the end section of the sheet W with respect to the suction holding member  33  due to the tension is regulated and an allowable state in which the movement of the end section of the sheet W with respect to the suction holding member  33  is allowed. In this case, as shown in  FIG. 23 , the pressing member  34  sandwiches (restrains) only the tip section of the sheet W between the pressing member  34  and the suction holding member  33 . 
     The cutting blade  35  and the pressing blade  36  are for cutting the sheet W provided between the suction holding member  33  and the holding roller  32 . Specifically, as indicated by a solid line and a chain double-dashed line in  FIG. 10 , the cutting blade  35  and the pressing blade  36  are attached to the opposing plates  31   a  and  31   b  so that the cutting blade  35  and the pressing blade  36  can move reciprocally in a direction parallel to a direction of reciprocal operations of the suction holding member  33  in accordance with extension/contraction operations of the cutting cylinder  38 . The cutting cylinder  38  includes: a cylinder main body fixed to the opposing plates  31   a  and  31   b ; and a rod which is extendable/contractible with respect to the cylinder main body and to which the cutting blade  35  and the pressing blade  36  are fixed. A sheet cutting valve  41  which controls extension/contraction operations of the cutting cylinder  38  by controlling supply of air to the cutting cylinder  38  and discharge of air from the cutting cylinder  38  is connected to the cutting cylinder  38 . 
     Referring to  FIG. 8 ,  FIG. 9 , and  FIG. 12 , the tape affixing unit  9 A is for affixing a tape T (an adhesive) to the end section of the sheet W held by the suction holding member  33  of the joining mechanism  28 A, and the tape affixing unit  9 B is for affixing the tape T to the end section of the sheet W held by the suction holding member  33  of the joining mechanism  28 B. Since the tape affixing units  9 A and  9 B have configurations symmetrical in the X direction, only the tape affixing unit  9 B will be described and a description of the tape affixing unit  9 A will be omitted. 
     The tape affixing unit  9 B includes: a fixed frame  44  which is fixed to the supporting plate  12 ; a moving frame  45  which is attached to the fixed frame  44  so as to be movable in the Y direction; a driving mechanism  66  which drives the moving frame  45 ; and a tape attaching mechanism (an adhesive attaching mechanism)  46  which is attached to the moving frame  45 . 
     Referring to  FIG. 9 ,  FIG. 12 , and  FIG. 13 , the fixed frame  44  includes: a top plate  44   a  extending from the supporting plate  12  toward an opposite side to the joining unit  8  in the Y direction; side plates  44   b  and  44   c  extending downward from both end sections of the top plate  44   a  in the X direction; and a rail  44   d  which is fixed to surfaces of the side plates  44   b  and  44   c  opposing each other and which extends in the Y direction. 
     The moving frame  45  is attached to the fixed frame  44  so as to be movable between a position (a position shown in  FIG. 12 ) at which the moving frame  45  protrudes from the supporting plate  12  toward a side of the joining mechanism  28 B through the through-hole  12   b  penetrating the supporting plate  12  in the Y direction and a position (a position shown in  FIG. 9 ) at which the moving frame  45  is retreated to a rear side of the supporting plate  12  through the through-hole  12   b  from a movement path (a rotation path) of the joining mechanism  28 B so as to allow a movement (a rotation) of the joining mechanism  28 B. 
     Specifically, the moving frame  45  includes: a base plate  45   a ; side plates  45   b  and  45   c  erected on both end sections in the X direction of the base plate  45   a ; a supporting plate  45   d  extending downwardly from one end section in the X direction of the base plate  45   a ; a slider  45   e  which is fixed to surfaces of the side plates  45   b  and  45   c  facing respectively opposite sides; and a slide rail  45   f  which engages with the slider  45   e . The slider  45   e  engages the slide rail  45   f  so as to be slidable in the Y direction, and the slide rail  45   f  engages the rail  44   d  so as to be slidable in the Y direction. 
     The driving mechanism  66  includes: a ball screw  66   a  attached to the fixed frame  44  in a state where the ball screw  66   a  is rotatable around an axis along the Y direction; a nut  66   b  which is screwed by the ball screw  66   a  and which is fixed to the moving frame  45  (the base plate  45   a ); and a moving motor  66   c  which rotationally drives the ball screw  66   a . As the ball screw  66   a  is rotated by the moving motor  66   c , the nut  66   b  and the moving frame  45  being fixed to the nut  66   b  move in the Y direction. 
     The tape attaching mechanism  46  is for attaching the tape T to the end section of the sheet W suctioned by the suction surface  33   d  of the joining mechanism  28 B. 
     In addition, the tape attaching mechanism  46  is attached to the supporting plate  45   d  of the moving frame  45 . Therefore, due to driving by the moving motor  66   c , the tape attaching mechanism  46  is configured to move between a tape attaching position (a position shown in  FIG. 12 ) at which the tape attaching mechanism  46  opposes the suction surface  33   d  in order to attach the tape T to the end section of the sheet W and a retreated position (a position shown in  FIG. 9 ) at which the tape attaching mechanism  46  is retreated from a movement path (a rotation path) of the suction holding member  33  so as to allow a movement (a rotation) of the suction holding member  33 . In other words, the fixed frame  44 , the moving frame  45 , and the driving mechanism  66  correspond to a movement supporting mechanism which supports the tape attaching mechanism  46  so as to be movable between the tape attaching position and the retreated position. 
     Specifically, the tape attaching mechanism  46  includes: a delivery roller  46   a  which holds a roll formed by winding the tape T is wound in a state where delivery of the tape T is allowed; a winding roller  46   b  which takes up a release paper of the tape T; a cutting blade  46   c  which cuts only an adhesive layer of the tape T; a pushing tool  46   d  which presses the adhesive layer of the tape T against the sheet W; a pushing tool cylinder  46   e  which drives the pushing tool  46   d  in the Z direction; a winding motor  46   f  which rotationally drives the winding roller  46   b ; and a pushing tool valve  46   g  which controls driving of the pushing tool cylinder  46   e.    
     When attaching the adhesive layer of the tape T to the sheet W, in a process of moving the tape attaching mechanism  46  from the retreated position to the tape attaching position, the winding motor  46   f  is driven to drive the pushing tool cylinder  46   e  and the tape T is pressed against the side of the sheet W with the pushing tool  46   d . Accordingly, a partial range of the adhesive layer (in the drawing, the adhesive layer is also denoted by reference character T for the sake of convenience) of the tape T having been cut by the cutting blade  46   c  is attached onto the sheet W. 
     Referring to  FIG. 1  and  FIG. 2 , the operation robot  3  retrieves the end section of the sheet W from the standby-side original material roll R 2  and conveys the end section of the sheet W to the joining unit  8 . In particular, the operation robot  3  is configured to convey the end section of the sheet W to the joining unit  8  from each of two sheet retrieval positions (positions of the end section of the sheet W suctioned by the suction roller  21 ) set in the sheet delivery system  1 . Therefore, the end section of the sheet W can be conveyed from both original material rolls R 1  and R 2  to the joining unit  8  without changing holding positions of the original material rolls R 1  and R 2  being held by the roll holding unit  5 . 
     Specifically, the operation robot  3  includes: a robot main body  47  which conveys the end section of the sheet W; and a moving mechanism  48  which supports the robot main body  47  so as to be movable in the X direction. 
     The robot main body  47  includes: a movable body  54  which is movably supported by the moving mechanism  48 ; and a multi-jointed arm  55  provided on the movable body  54 . 
     The multi-jointed arm  55  includes: a turning section  56  attached to the movable body  54  in a state where the turning section  56  is turnable around a turning axis J 1  along the Z axis direction; a first arm  57  attached to the turning section  56  in a state where the first arm  57  is swingable around a first horizontal direction axis J 2 ; a second arm  58  attached to the first arm  57  in a state where the second arm  58  is swingable around a second horizontal direction axis J 3 ; a third arm  59  attached to the second arm  58  in a state where the third arm  59  is rotatable around a third horizontal direction axis J 4 ; and a hand  60  attached to the third arm  59  in a state where the hand  60  is swingable around an axis J 5  that is perpendicular to the third axis J 4 . 
     In addition, the multi-jointed arm  55  includes: a first motor  61  which turnably drives the turning section  56  with respect to the movable body  54 ; a second motor  62  which drives the first arm  57  with respect to the turning section  56 ; a third motor  63  which drives the second arm  58  with respect to the first arm  57 ; a fourth motor  64  which rotationally drives the third arm  59  with respect to the second arm  58 ; and a fifth motor  65  which drives the hand  60  with respect to the third arm  59 . 
     Referring to  FIG. 5  and  FIG. 7 , the hand  60  corresponds to a grasping unit or a sheet holding unit configured to grasp the end section of the sheet W of the original material rolls R 1  and R 2 . The hand  60  includes: an extending section  60   a  which extends from the third arm  59 ; a pair of grasping actuators  60   b  provided on a tip section of the extending section  60   a ; grasping units  60   d  and  60   e  attached to the grasping actuators  60   b ; a plurality of grasping claws  60   f  provided on the grasping units  60   d  and  60   e ; and a grasping valve  60   c  which controls driving of the grasping actuators  60   b.    
     The grasping actuators  60   b  include: an actuator main body (reference symbol omitted); and a pair of driving units  60   g  and  60   h  which protrude from the actuator main body. The pair of driving units  60   g  and  60   h  approach each other as air is supplied to the actuator main body and separate from each other as air is discharged from the actuator main body. The grasping valve  60   c  is configured to control supply of air to the grasping actuators  60   b  and discharge of air from the grasping actuators  60   b.    
     The grasping unit  60   d  is attached to the driving unit  60   g . On the other hand, the grasping unit  60   e  is attached to the driving unit  60   h.    
     As shown in  FIG. 5 , the grasping claws  60   f  are arranged at a same pitch as a pitch of spaces between adjacent suction rollers  21 . In addition, each of the grasping claws  60   f  has a size and shape that enables the grasping claws  60   f  to be inserted to the spaces between adjacent suction rollers  21 . Furthermore, the grasping claw  60   f  provided on the grasping unit  60   d  and the grasping claw  60   f  provided on the grasping unit  60   e  oppose each other. Therefore, as shown in  FIG. 18 , in a state where the grasping claw  60   f  is inserted between suction rollers  21 , the end section of the sheet W suctioned by the suction rollers  21  can be grasped by the grasping claw  60   f.    
     In other words, in the multi jointed arm  55 , the turning section  56 , the arms  57  to  59 , and the motors  61  to  65  correspond to a supporting mechanism which supports the hand  60  in a state where the hand  60  is movable within a movement range set in advance. 
     On the other hand, the moving mechanism  48  shown in  FIG. 1  movably supports the supporting mechanism between an operating position (a position indicated by a chain double-dashed line in  FIG. 3 ) at which the joining unit  8  and a retrieval position (the suction roller  21 ) of the sheet W with respect to the original material rolls R 1  and R 2  is within the movement range of the supporting mechanism and a standby position (a position indicated by a solid line in  FIG. 3 ) at which the supporting mechanism is separated from the joining unit  8  as compared to the operating position. 
     Specifically, as shown in  FIG. 3  and  FIG. 4 , the moving mechanism  48  includes: a main body unit  49 ; a pair of pulleys  50   a  and  50   b  rotatably supported around an axis along the Y direction with respect to the main body unit  49 ; a belt  51  provided between the pulleys  50   a  and  50   b ; a moving motor  52  which rotationally drives the pulley  50   a ; and a rail  53  (refer to  FIG. 4 ) fixed to the main body unit  49 . 
     On the other hand, the movable body  54  of the robot main body  47  includes: a movable body main body  54   a  provided on the main body unit  49 ; a slider  54   b  which is fixed to a lower surface of the movable body main body  54   a  and which engages the rail  53  in a state where the slider  54   b  is slidable in the X direction; and a fixed section  54   e  which is fixed to a part of the belt  51  positioned between both pulleys  50   a  and  50   b.    
     When the pulley  50   a  is rotated by the moving motor  52 , in accordance with a movement of the part of the belt  51  positioned between both pulleys  50   a  and  50   b , the fixed section  54   c  which is fixed thereto moves in the X direction. As a result, the slider  54   b  slides relative to the rail  53  and, accordingly, the movable body main body  54   a  fixed to the slider  54   b  and the robot main body  47  supported by the movable body main body  54   a  move in the X direction. 
     In addition, the main body unit  49  of the moving mechanism  48  includes: a standby position detector  49   a  (refer to  FIG. 4 ) configured to detect that the robot main body  47  (the movable body  54 ) is moved to the standby position; and an operating position detector  49   b  (refer to  FIG. 14 ) configured to detect that the robot main body  47  is moved to the operating position. Both detectors  49   a  and  49   b  are respectively configured to detect whether or not the fixed section  54   c  of the movable body  54  has reached a position corresponding to the standby position or whether or not the fixed section  54   c  has reached a position corresponding to the operating position. 
     Moreover, a portion of the operation robot  3  other than the hand  60  corresponds to a holding unit driving mechanism which drives the hand  60 . 
     Referring to  FIG. 1  and  FIG. 14 , the controller  70  controls driving of the roll holding units  5 A and  5 B, the end section retrieving units  7 A and  7 B, the joining unit  8 , the tape affixing units  9 A and  9 B, and the operation robot  3  based on results of detections by the remaining sheet amount detector  16 , the rotational angle detector  25 , the end section detector  27 , the standby position detector  49   a , and the operating position detector  49   b.    
     Specifically, the controller  70  includes: a holding control unit  71  which controls driving of the roll holding units  5 A and  5 B; a retrieval control unit  72  which controls driving of the end section retrieving units  7 A and  7 B; an affixing control unit  73  which controls driving of the tape affixing units  9 A and  9 B; a joining control unit  74  which controls driving of the joining unit  8 ; and a robot control unit  75  which controls driving of the operation robot  3 . 
     The holding control unit  71  starts driving of the roll driving motor  15  when the remaining sheet amount detector  16  detects that a remaining roll amount of the delivery-side original material roll R 1  is smaller than a remaining amount set in advance. On the other hand, the holding control unit  71  stops the roll driving motor  15  when the end section detector  27  detects an end section of the standby-side original material roll R 2  on the suction roller  21 . 
     The retrieval control unit  72  controls driving of the rotary valve  24  so that the suction roller  21  comes into contact with the original material rolls R 1  and R 2  based on results of detections by the remaining sheet amount detector  16  and the rotational angle detector  25 . 
     When a position of the suction roller  21  is changed in accordance with a remaining amount of the sheet W of the original material rolls R 1  and R 2  in this manner, a retrieval position of the sheet W by the operation robot  3  changes in accordance with the change. 
     Therefore, as shown in  FIG. 17 , the retrieval control unit  72  calculates an amount of variation of a position of an end section of the sheet W with respect to a reference position (for example, a position indicated by a chain double-dashed line in  FIG. 17 ) set in advance, based on a positional relationship (a radius of rotation R) between the rotary shaft  17  and the end section detector  27  and rotational angles of the arms  18   a  and  18   b  detected by the rotational angle detector  25 . 
     Specifically, the retrieval control unit  72  calculates a movement distance D 1  based on an angular difference θ 1  between a reference position and a current position of the arms  18   a  and  18   b  and the radius of rotation R. In addition, the retrieval control unit  72  calculates an amount of variation ΔX in the X direction and an amount of variation ΔZ in the Z direction based on an angular difference θ 2  with respect to the X direction of a movement direction of the arms  18   a  and  18   b  from the reference position to the current position and the movement distance D 1 . 
     Furthermore, the retrieval control unit  72  separates the sheet W from the original material rolls R 1  and R 2  using the suction roller  21  by opening the suction valve  26  at a timing set in advance. 
     The robot control unit  75  controls the moving motor  52  based on results of detections by the standby position detector  49   a  and the operating position detector  49   b  so that the robot main body  47  moves to the standby position in a situation where the sheet W is being delivered from one of the original material rolls R 1  and R 2  and that the robot main body  47  moves to the operating position in a situation where a joining operation of the sheet W is required. 
     In addition, the robot control unit  75  controls the first to fifth motors  61  to  65  so that the hand  60  moves toward a sheet retrieval position calculated by the retrieval control unit  72 , and controls the grasping valve  60   c  so that the sheet W suctioned by the suction roller  21  is grasped by the hand  60  as shown in  FIG. 18 . 
     Furthermore, as shown in  FIG. 19 , the robot control unit  75  controls driving of the first to fifth motors  61  to  65  so that the hand  60  grasping the sheet W moves along a path which passes above, to the right, and below the support roller  6   b  and which reaches the joining mechanism  28 B. 
     Moreover, as shown in  FIG. 20  to  FIG. 22 , the robot control unit  75  controls the first to fifth motors  61  to  65  and the grasping valve  60   c  so that the hand  60  places the end section of the sheet W on the suction surface  33   d  of the suction holding member  33 , the hand  60  releases its hold on the end section of the sheet W, and the hand  60  further rubs the end section of the sheet W placed on the suction surface  33   d  along the suction surface  33   d.    
     In this case, as shown in  FIG. 21  and  FIG. 22 , the robot control unit  75  controls the first to fifth motors  61  to  65  and the grasping valve  60   c  so that the hand  60  places the end section of the sheet W on the suction surface  33   d  so that the tip section of the sheet W exceeds an edge of the suction surface  33   d  and is arranged outside of the suction surface  33   d , the hand  60  releases its hold on the end section of the sheet W, and the hand  60  further pushes the tip section of the sheet W along the pressed surface  33   e  so that the tip section of the sheet W bends along the pressed surface  33   e.    
     The joining control unit  74  controls the rotary valves  30 A and  30 B so that, as shown in  FIG. 27 , the joining mechanisms  28 A and  28 B are arranged at the delivery position during a delivery period of the sheet W of one of the original material rolls R 1  and R 2 . On the other hand, when a joining operation is required, as shown in  FIG. 19 , the joining control unit  74  controls the rotary valve  30 B so that the joining mechanism  28 B is arranged at the mounting position in order to mount the end section of the sheet W of the standby-side original material roll R 2  and, at the same time, opens the suction valve  43  to enable the sheet W to be suctioned by the suction surface  33   d.    
     In addition, after the tip section of the sheet W is bent along the pressed surface  33   e  by the hand  60  as shown in  FIG. 22 , the joining control unit  74  controls the sheet pressing valve  42  so that the tip section of the sheet W is sandwiched between the pressed surface  33   e  and the pressing member  34  as shown in  FIG. 23 . Although details will be provided later, in this state, the tape T is affixed to the end section of the sheet W on the suction surface  33   d . Furthermore, the joining control unit  74  continues pressing the tip section of the sheet W at least while the joining mechanism  28 B moves from the mounting position to the delivery position. 
     Moreover, the joining control unit  74  controls the rotary valve  30 B so that the joining mechanism  28 B moves from the mounting position to the delivery position as shown in  FIG. 24 , and controls the push-in valve  40  so that the suction holding member  33  of the joining mechanism  28 A approaches the suction holding member  33  of the joining mechanism  28 B as shown in  FIG. 25 . Accordingly, the sheet W of the delivery-side original material roll R 1  and the sheet W of the standby-side original material roll R 2  are joined via the tape T. 
     In this state, as shown in  FIG. 26 , the joining control unit  74  controls the sheet cutting valve  41  so that the cutting blade  35  and the pressing blade  36  of the joining mechanism  28 A are projected toward a side of the joining mechanism  28 B. Accordingly, the sheet W of the delivery-side original material roll R 1  is cut. 
     The affixing control unit  73  controls the moving motor  66   c  so that, in a state where the joining mechanism  28 B is rotated to the mounting position as shown in  FIG. 23 , the tape attaching mechanism  46  is positioned at the tape attaching position as shown in  FIG. 12  and, before the joining mechanism  28 B rotates to the delivery position, the tape attaching mechanism  46  is positioned at the retreated position. 
     In addition, the affixing control unit  73  controls the winding motor  46   f  and the pushing tool valve  46   g  so that the adhesive layer of the tape T is attached to the sheet W by taking up the release paper of the tape T and pushing the pushing tool  46   d  toward the side of the sheet W during the movement of the tape attaching mechanism  46  to the tape attaching position. 
     Hereinafter, a process executed by the controller  70  will be described with reference to  FIG. 15  and  FIG. 16 . 
     The process by the controller  70  is started in a state where both joining mechanisms  28 A and  28 B are arranged at the delivery position as shown in  FIG. 27  (while the sheet W of the original material roll R 2  is being delivered in  FIG. 27 , in a present stage, the original material roll R 1  is being delivered). In other words, a case of the process by the controller  70  being started in a state where a delivery step is being executed in which the sheet W is being delivered from the delivery-side original material roll R 1  will be described. 
     First, based on a result of detection by the remaining sheet amount detector  16 , a determination is made on whether or not a remaining sheet amount of the delivery-side original material roll R 1  is below a remaining amount set in advance (step S 1 ). 
     When it is determined that the remaining sheet amount is below the remaining amount set in advance, as shown in  FIG. 19 , the joining mechanism  28 B is rotated to the mounting position and, at the same time, suction by the suction holding member  33  is started (step S 2 ). 
     Next, both arms  18   a  and  18   b  are rotated so that the suction roller  21  approaches the standby-side original material roll R 2  and, at the same time, suction by the suction roller  21  is started (step S 3 ). Accordingly, the suction roller  21  enters a state where the suction roller  21  is capable of coming into rolling contact with the standby-side original material roll R 2  in accordance with rotational driving of the standby-side original material roll R 2 . 
     In this case, the standby-side original material roll R 2  is rotated counterclockwise in  FIG. 19  (step S 4 ). In other words, in steps S 1  and S 4 , a rotational driving process is performed in which the standby-side original material roll R 2  is rotationally driven when the remaining amount of the sheet W of the delivery-side original material roll R 1  falls below the remaining amount set in advance. 
     Next, a determination is made on whether or not the end section of the sheet W suctioned by the suction roller  21  is detected by the end section detector  27  (step S 5 : detecting step). 
     When it is determined that the end section of the sheet W is not detected, driving of the standby-side original material roll R 2  in step S 4  is continued. 
     On the other hand, when it is determined that the end section of the sheet W is detected as shown in  FIG. 17 , driving of the standby-side original material roll R 2  is stopped (step S 6 ), and the robot main body  47  is moved to the operating position as indicated by the chain double-dashed line in  FIG. 1  and the hand  60  is arranged at a position (a preparation position) in a vicinity of the end section retrieving unit  7 B (step S 7 ). 
     Next, a position of the end section of the sheet W detected by the end section detector  27  is computed as shown in  FIG. 17  (step S 8 ), and the end section of the sheet W held by the suction roller  21  is grasped by the hand  60  as shown in  FIG. 18  (step S 9 ). 
     In this state, as shown in  FIG. 19  and  FIG. 20 , the hand  60  is moved along a path set in advance so that the sheet W grasped by the hand  60  is guided via the support roller  6   b  to the suction surface  33   d  of the suction holding member  33  of the joining mechanism  28 B (step S 10 ). 
     In other words, in steps S 1  to S 10 , a conveying step is performed in which the end section of the sheet W of the standby-side original material roll R 2  is retrieved using the operation robot  3  and the end section of the sheet W is conveyed to the suction holding member  33  when the remaining amount of the sheet W of the delivery-side original material roll R 1  falls below the remaining amount set in advance. 
     By executing step S 10 , when the end section of the sheet W is suctioned by the suction surface  33   d  as shown in  FIG. 21 , the hand  60  is released and, at the same time, the sheet W is smoothed by rubbing, along the suction surface  33   d , the end section of the sheet W having been placed on the suction surface  33   d  by the hand  60  (step S 11 ). Accordingly, even when the sheet W suctioned by the suction surface  33   d  is slack, the slack of the sheet W can be taken up before affixing the tape T as will be described later. 
     Next, as shown in  FIG. 22 , the tip section of the sheet W is folded along the pressed surface  33   e  with the hand  60  (step S 12 ) and, the hand  60  is separated from the joining mechanism  28 B to move the robot main body  47  to the standby position indicated by the solid line in  FIG. 1  (step S 13 ). 
     In this state, the tip section of the sheet W is pressed between the pressing member  34  and the pressed surface  33   e  by rotating the pressing member  34  (step S 14 ). 
     Subsequently, both arms  18   a  and  18   b  are rotated so that the suction roller  21  separates from the standby-side original material roll R 2  (step S 15 ) and, the standby-side original material roll R 2  is rotated in reverse (clockwise in  FIG. 19 ) in order to take up the slack of the sheet W on the suction surface  33   d  (step S 16 ). 
     In this state, the adhesive layer of the tape T is attached to the sheet W as shown in  FIG. 23  by advancing the tape attaching mechanism  46  from the retreated position shown in  FIG. 9  to a position set in advance (step S 17 ), lowering the pushing tool  46   d , and advancing the tape attaching mechanism  46  (step S 18 ). 
     Next, the pushing tool  46   d  is raised and the tape attaching mechanism  46  is retreated to the retreated position (step S 19 ), and the joining mechanism  28 B is rotated to the delivery position as shown in  FIG. 24  (step S 20 ). 
     In this state, rotation of the delivery-side original material roll R 1  is stopped (step S 21 ). In step S 21 , at the same time the rotation of the delivery-side original material roll R 1  is stopped, the upper roller group  6 A and the lower roller group  6 B of the sheet storage mechanism  6   h  shown in  FIG. 1  are brought close to each other. Accordingly, even after the rotation of the delivery-side original material roll R 1  is stopped, delivery of the sheet W can be continued in correspondence to a reduction in length of the path of the sheet W in the sheet storage mechanism  6   h.    
     Subsequently, pressing of the sheet W by the pressing member  34  is released as shown in  FIG. 24  (step S 22 ), and the suction holding member  33  of the joining mechanism  28 A is caused to protrude to the side of the suction holding member  33  of the joining mechanism  28 B as shown in  FIG. 25  (step S 23 ). Accordingly, the end section of the sheet W of the standby-side original material roll R 2  is joined to the intermediate section of the sheet W of the delivery-side original material roll R 1 . 
     In other words, in steps S 12  to S 23 , a joining step is performed in which the end section of the sheet W of the standby-side original material roll R 2  is joined to the intermediate section of the sheet W of the delivery-side original material roll R 1  by moving the suction surface  33   d  of the suction holding member  33  toward the intermediate section of the sheet W of the delivery-side original material roll R 1  while restricting movement of the end section of the sheet W with respect to the suction holding member  33 . 
     In this state, by causing the cutting blade  35  and the pressing blade  36  of the joining mechanism  28 A to protrude to the side of the joining mechanism  28 B as shown in  FIG. 26  (step S 24 ), the sheet W of the delivery-side original material roll R 1  is cut. 
     As a result, in accordance with tension applied to the sheet W, the sheet W is delivered from the standby-side original material roll R 2  as shown in  FIG. 27  (the standby-side original material roll R 2  becomes a next delivery-side original material roll). Subsequently, by attaching the new standby-side original material roll R 1  to the roll holding unit  5 A, when a remaining amount of the sheet W of the delivery-side original material roll R 2  becomes small, an end section of the sheet W of the standby-side original material roll R 1  can be joined to the sheet W of the delivery-side original material roll R 2 . 
     As described above, during the movement of the suction surface  33   d  toward the intermediate section of the sheet W of the delivery-side original material roll R 1 , a movement of the end section of the sheet W with respect to the suction holding member  33  can be regulated by the regulating mechanism (the opposing plates  31   a  and  31   b , the shafts  39   a  and  39   b , the sheet pressing cylinder  39 , the sheet pressing valve  42 , and the pressing member  34 ) of the suction holding member  33 . 
     Therefore, a holding position of the sheet W with respect to the suction holding member  33  can be prevented from changing during a movement of the suction holding member  33 . 
     Furthermore, the first embodiment also achieves the following effects. 
     Since only a tip section of the sheet W is restrained in the regulated state, slack formed on the sheet W can be taken up using tension applied to the sheet W. 
     When slack is formed on an end section of the sheet W on the suction surface  33   d , the slack formed on the sheet W can be smoothed by moving the hand  60  so as to rub the sheet W. 
     Since the tip section of the sheet W can be pressed between the pressing member  34  and the pressed surface  33   e  which extends in a direction opposite to a direction to which the suction surface  33   d  face, a movement of the sheet W can be regulated without the regulating mechanism (the pressing member  34 ) being an obstacle in a process of bringing the suction surface  33   d  close to the delivery-side original material roll R 1 . 
     In addition, such regulation of the movement of the sheet W can be automatically performed by the hand  60  and the pressing member  34 . 
     The tape T can be attached to the end section of the sheet W suctioned by the suction surface  33   d  by moving the tape attaching mechanism  46  to the tape attaching position shown in  FIG. 12 , and the suction holding member  33  can be moved by moving the tape attaching mechanism  46  to the retreated position shown in  FIG. 9 . 
     Accordingly, the tape T can be attached to the end section of the sheet W while avoiding interference with the suction holding member  33 . 
     &lt;Second Embodiment&gt; 
     Although the first embodiment includes a single joining unit  8  for joining the sheet W of the original material roll R 1  and the sheet W of the original material roll R 2  to each other, the joining unit  8  may be provided in plurality. 
     Specifically, a sheet delivery system  1  according to the second embodiment shown in  FIG. 28  includes two sheet delivery apparatuses  2  described earlier. Specifically, the sheet delivery system  1  further includes a joining unit  8  (an alternative joining unit) configured to perform a joining operation of a sheet W of original material rolls R 1  and R 2  (an alternative delivery-side original material roll and an alternative standby-side original material roll) which are separate from the original material rolls R 1  and R 2  described above. Therefore, sheets W of two types can be continuously delivered. 
     On the other hand, the sheet delivery system  1  according to the second embodiment includes a single operation robot  3  configured to convey the end section of the sheet W from each of four sheet retrieval positions (end section retrieving units  7 A and  7 B) to both joining units  8 . 
     Specifically, the operation robot  3  according to the second embodiment includes a moving mechanism  48  which supports a robot main body  47  between two operating positions (positions indicated by chain double-dashed lines in  FIG. 28 ) at which one joining unit  8 , one end section retrieving unit  7 A, and one end section retrieving unit  7 B are arranged in a movement range of a hand  60 , and a standby position (a position indicated by a solid line in  FIG. 28 ) at which the robot main body  47  is retreated in comparison to the operating positions. 
     Accordingly, joining operations at the two joining units  8  can be executed by one operation robot  3 . 
     Moreover, while an example in which two joining units  8  are provided has been described, joining operations can be performed by one operation robot  3  even when a plurality of joining units  8  are provided. 
     In addition, the sheet delivery system  1  according to the second embodiment includes a roller driving motor (a suction roller driving unit)  76  which rotationally drives a suction roller  21 . Therefore, a sheet holding position at which the sheet W is held by the hand  60  can always be kept constant. 
     For example, a case where a position of the suction roller  21  (the end section of the sheet W) indicated by the solid line in  FIG. 17  is set in advance as a sheet holding position will be described. When the end section of the sheet W is detected at the position indicated by the chain double-dashed line in  FIG. 17 , the suction roller  21  can be rotated to the sheet holding position by rotating both arms  18   a  and  18   b  based on a result of detection by a rotational angle detector  25 . 
     However, rotating both arms  18   a  and  18   b  causes the suction roller  21  to rotate due to tension created on the sheet W and changes a position of the end section of the sheet W. 
     In consideration thereof, by rotating the suction roller  21  with the roller driving motor  76 , the position of the end section of the sheet W can be returned to a position which can be detected by an end section detector  27  or, in other words, the sheet holding position. 
     Furthermore, while an example in which two original material rolls R 1  and R 2  are held with respect to one joining unit  8  has been described, a plurality of original material rolls may be held with respect to one joining unit  8 . 
     The specific embodiment described above mainly includes an invention configured as described below. 
     Specifically, the present invention provides a sheet delivery system for continuously delivering a sheet, the sheet delivery system including: a roll holding unit which holds a plurality of original material rolls, each formed by winding a sheet, in a state where delivery of the sheet is allowed; a joining unit which joins, to an intermediate section of a sheet being delivered from a delivery-side original material roll among the plurality of original material rolls held by the roll holding unit, an end section of a sheet of a standby-side original material roll that is a roll other than the delivery-side original material roll among the plurality of original material rolls held by the roll holding unit; an end section conveying apparatus which retrieves the end section of the sheet from the standby-side original material roll and which conveys the end section of the sheet to the joining unit; and a controller which controls an operation of the joining unit, wherein the joining unit includes: a suction holding member having a suction surface configured to suction the end section of the sheet of the standby-side original material roll conveyed by the end section conveying apparatus; a moving mechanism configured to move the suction surface of the suction holding member toward the intermediate section of the sheet of the delivery-side original material roll along a path set in advance so that tension is applied to a sheet between the standby-side original material roll and the suction holding member; and a regulating mechanism that is configured to switch between a regulated state in which a movement of the end section of the sheet with respect to the suction holding member due to the tension is regulated and an allowable state in which the movement of the end section of the sheet with respect to the suction holding member is allowed, and the controller switches the regulating mechanism to the regulated state during the movement of the suction surface toward the intermediate section of the sheet of the delivery-side original material roll. 
     As described above, during the movement of the suction surface toward the intermediate section of a sheet of the delivery-side original material roll, a movement of an end section of a sheet with respect to the suction holding member can be regulated by the regulating mechanism of the suction holding member. 
     Therefore, according to the present invention, a holding position of a sheet with respect to the suction holding member can be prevented from changing during a movement of the suction holding member. 
     The regulating member can restrain an entire end section of a sheet with respect to the suction holding member. However, in this case, when slack is formed in an end section of the sheet on the suction surface, since a movement of the entire end section of the sheet is regulated by the restraint applied by the regulating member, the slack formed on the sheet cannot be taken up. When attaching an adhesive on the end section of the sheet, slack of the sheet hinders the attachment of the adhesive. 
     In consideration thereof, in the sheet delivery system described above, the regulating mechanism favorably restrains only a tip section of the sheet with respect to the suction holding member in the regulated state. 
     According to this aspect, since only the tip section of the sheet is restrained in the regulated state, slack formed on the sheet can be stretched using tension applied to the sheet. 
     In the sheet delivery system described above, favorably, the end section conveying apparatus includes a sheet holding unit which holds the end section of the sheet of the standby-side original material roll, and a holding unit driving mechanism which drives the sheet holding unit, and the controller controls the holding unit driving mechanism so that: the sheet holding unit places the end section of the sheet on the suction surface of the suction holding member; the sheet holding unit releases the hold on the end section of the sheet; and the sheet holding unit further rubs, along the suction surface, the end section of the sheet placed on the suction surface. 
     According to this aspect, when slack is formed on an end section of a sheet on the suction surface, the slack formed on the sheet can be smoothed by having the sheet holding unit move so as to rub the sheet. 
     While the regulation of a sheet by the regulating mechanism can be performed by, for example, sandwiching an end section of the sheet between the regulating mechanism and the suction surface, in this case, the regulating mechanism must be retreated during a process of bringing the suction surface close to the intermediate section of the sheet of the delivery-side original material roll. 
     In consideration thereof, favorably, in the sheet delivery system described above, the suction holding member includes a pressed surface which extends from an edge of the suction surface in a direction opposite to a direction to which the suction surface faces, the regulating mechanism includes: a pressing member having a pressing surface which sandwiches a tip section of the sheet between the pressing surface and the pressed surface; and a pressing driving mechanism which drives the pressing member so that the pressing surface approaches and retreats from the pressed surface, and the controller controls the holding unit driving mechanism so that: the sheet holding unit places the end section of the sheet on the suction surface so that the tip section of the sheet exceeds the edge of the suction surface and is arranged outside of the suction surface; the sheet holding unit releases the hold on the end section of the sheet; and the sheet holding unit further pushes the tip section of the sheet along the pressed surface so that the tip section of the sheet bends along the pressed surface, and the controller controls the pressing driving mechanism so that the tip section of the sheet pushed along the pressed surface becomes sandwiched between the pressed surface and the pressing surface. 
     According to this aspect, since a tip section of a sheet can be pressed between the pressing member and the pressed surface which extends in a direction opposite to a direction to which the suction surface faces, movement of the sheet can be regulated without the regulating mechanism (the pressing member) being an obstacle in a process of bringing the suction surface close to the delivery-side original material roll. 
     In addition, such regulation of the movement of a sheet can be automatically performed by the sheet holding unit and the pressing member. 
     Favorably, the sheet delivery system described above includes: an adhesive attaching mechanism which attaches, to the end section of the sheet suctioned by the suction surface, an adhesive for attaching the end section of the sheet of the standby-side original material roll to the intermediate section of the sheet of the delivery-side original material roll; and a movement supporting mechanism which supports the adhesive attaching mechanism so as to be movable between an adhesive attaching position at which the adhesive attaching mechanism opposes the suction surface in order to attach the adhesive to the end section of the sheet and a retreated position at which the adhesive attaching mechanism is retreated from a movement path of the suction holding member so as to allow a movement of the suction holding member. 
     According to this aspect, the adhesive can be attached to an end section of a sheet suctioned by the suction surface by moving the adhesive attaching mechanism to the adhesive attaching position, and the suction holding member can be moved by moving the adhesive attaching mechanism to the retreated position. 
     As a result, the adhesive can be attached to an end section of a sheet while avoiding interference with the suction holding member. 
     In addition, the present invention provides a sheet delivery method using the sheet delivery system described above, the sheet delivery method including: a delivery step of delivering a sheet from the delivery-side original material roll; a conveying step of retrieving an end section of a sheet of the standby-side original material roll and conveying the end section of the sheet to the suction holding member of the joining unit using the end section conveying apparatus when a remaining sheet amount of the delivery-side original material roll falls below a remaining amount set in advance by the delivery step; and a joining step of joining the end section of the sheet of the standby-side original material roll to an intermediate section of the sheet of the delivery-side original material roll by moving the suction surface of the suction holding member toward the intermediate section of the sheet of the delivery-side original material roll using the moving mechanism while regulating a movement of the end section of the sheet with respect to the suction holding member using the regulating mechanism. 
     According to the present invention, since movement of an end section of a sheet with respect to the suction holding member can be regulated by the regulating mechanism, a holding position of a sheet with respect to the suction holding member can be prevented from changing during a movement of the suction holding member.