Tension applying mechanism and conveying device with tension applying mechanism

Abstract

To provide a tension application mechanism capable of easily rotating a tension arm with a one-way clutch in a direction where the one-way clutch is locked.SOLUTION: A tension application mechanism 1 comprises: a clutch unit 2 that houses in a housing 25 a one-way clutch 21 that applies tension to a circulating endless member 86 and allows rotation in one direction around a clutch shaft; an arm 3 connected to the clutch shaft of the clutch unit 2 and rotatable around the clutch shaft; and a tension pulley 43 that is rotatably supported by the arm 3, and applies tension to the endless member 86. The housing 25 or the arm 3, here the housing 25, is rotatably provided in a second direction opposite to a first direction with respect to the clutch shaft.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a tension applying mechanism for an endless rotating member. [Background technology]

[0002] For example, as a mechanism for automatically adjusting the tension of an endless member such as a drive belt, a "device for automatically adjusting the tension of a drive belt in which a one-way clutch attached within the boss portion of the base of a tension arm having a tension pulley pivotally attached to the tip is attached to a fixed shaft of the main body, a tension spring is provided to rotate the tension arm toward the drive belt, and the pulley is pressed against the belt" has been proposed (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 62-181750 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned automatic tension adjusting device has a problem in that, for example, it is difficult to return the tension arm to the side opposite the drive belt, that is, to rotate the tension arm in the locking direction of the one-way clutch. In other words, in the above-mentioned automatic adjustment device, the tension arm needs to rotate approximately one revolution in the rotational direction of the one-way clutch, but due to the presence of a motor pulley for the drive belt and the like, the tension arm cannot be rotated one revolution. The situation in which the one-way clutch is returned in the locking direction occurs, for example, when the drive belt is replaced, or when a chain member is used as the endless member and a link of the chain member is removed to shorten the chain member. The problem to be solved by the present invention is to provide a tension applying mechanism that can easily rotate an arm (tension arm) with a one-way clutch in the locking direction of the one-way clutch. [Means for solving the problem]

[0005] A tension applying mechanism according to one embodiment of the present invention is a tension applying mechanism for an endless member that moves in a circulating manner, and comprises a clutch unit that accommodates a one-way clutch that allows rotation in one direction around a clutch shaft within a housing, an arm that is connected to the clutch shaft of the clutch unit and can rotate around the clutch shaft, and a tension pulley that is rotatably supported on the arm and applies tension to the endless member, and the housing or the arm is rotatably arranged relative to the clutch shaft in a second direction that is opposite to the first direction. Effect of the Invention

[0006] According to the present invention, the tension arm with the one-way clutch can be easily rotated in the locking direction of the one-way clutch. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a transport device according to a first embodiment. [Diagram 2] 5A and 5B are side views of the tension applying mechanism, in which FIG. 5A shows the tension applying mechanism in an assembled state, and FIG. 5B shows the tension applying mechanism with the outer plate in the width direction removed. [Diagram 3] 3A is a cross-sectional view of the tension applying mechanism, in which FIG. 3A is a cross-sectional view taken along the line AA in FIG. 2A as viewed from the arrow side, and FIG. 3B is a cross-sectional view taken along the line BB in FIG. 2A as viewed from the arrow side. [Figure 4] 11A and 11B are diagrams for explaining a state in which the tension applying mechanism is used. [Diagram 5] 5A and 5B are perspective views of a tension applying mechanism according to a second embodiment, in which (a) is a diagram in an assembled state and (b) is a diagram in a partially disassembled state so that the structure can be seen. [Figure 6]3 is a cross-sectional view taken along the line AA in FIG. 2(a). [Figure 7] 10A and 10B are diagrams relating to modified examples, in which FIG. 10A is a diagram of a tension applying mechanism corresponding to the first embodiment, and FIG. 10B is a diagram of a tension applying mechanism corresponding to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] <Summary> A first tension applying mechanism according to one aspect of the present invention is a tension applying mechanism for an endless member that moves in a circulating manner, the tension applying mechanism comprising: a clutch unit that accommodates a one-way clutch that allows rotation in one direction about a clutch shaft in a housing, an arm that is connected to the clutch shaft of the clutch unit and is rotatable about the clutch shaft, and a tension pulley that is rotatably supported by the arm and applies tension to the endless member, the housing or the arm being rotatably provided relative to the clutch shaft in a second direction opposite to the first direction, whereby the arm can be easily moved in the locking direction. A second tension applying mechanism according to another embodiment is the first tension applying mechanism, in which the housing is rotatably attached to a support member that supports the clutch unit in the second direction, and the arm is attached to the clutch shaft so as not to rotate around the shaft, thereby easily implementing a tension applying mechanism in which the arm can move in the lock direction. A third tension applying mechanism according to another embodiment is the first tension applying mechanism, wherein the arm is rotatably attached to the clutch shaft in the second direction, and the housing is attached to a support member that supports the clutch unit so as not to rotate around the clutch shaft, thereby easily implementing a tension applying mechanism in which the arm can move in the locking direction. A fourth tension applying mechanism according to another embodiment is any one of the first to third tension applying mechanisms, further comprising a sensor that detects that the movement of the arm in the first direction has reached a predetermined position, thereby making it possible to prevent the arm from being left in a state where it has reached the predetermined position.

[0009] First Embodiment The first embodiment will be described in detail below with reference to the drawings.

[0010] 1. Overall structure The tension applying mechanism 1 according to the first embodiment is provided in a conveying device 7 that uses a chain member or a belt member and conveys an object to be conveyed. Here, the direction in which the object to be conveyed is conveyed using the chain member is defined as the conveying direction. As shown in FIG. 1, the transport device 7 includes one or more conveyor units 80, a drive unit 81 for driving the conveyor units 80, and a tension applying mechanism 1. Here, there are two conveyor units 80 spaced apart in a direction perpendicular to the conveying direction, and they are connected by a connecting member 82. Note that the drive unit 81 here is provided in one of the conveyor units 80. Here, the transport direction of the transported object is also referred to as the longitudinal direction of the transport device 7 or simply as the longitudinal direction, the direction in which the drive shaft 91 of the drive unit 81 extends or the direction in which the two conveyor units 80 are arranged side by side is also referred to as the width direction of the transport device 7 or simply as the width direction, and the direction perpendicular to the longitudinal direction and width direction of the transport device 7 is also referred to as the height direction or up-down direction.

[0011] The conveyor unit 80 includes a frame 84 extending in the conveying direction, a sprocket (not shown) provided at one end of the frame 84 in the conveying direction, a driven roller 85 (see FIG. 2(b)) provided at the other end of the frame 84 in the conveying direction, and a chain member 86 that moves in a circular motion by winding around the sprocket and the driven roller 85. The sprocket is rotatably fixed to the frame 84 via a pair of plates 87, and the driven roller 85 is rotatably fixed to the frame 84 via a pair of plates 88. The chain member 86 has inner links and outer links connected to each other, but is shown in the figure as a belt for convenience. The drive unit 81 includes a motor 89 and an orthogonal-axis type gear head 90, and the drive shaft 91 connected to the gear head 90 is connected to a sprocket of the conveyor unit 80. The drive unit 81 is fixed to the frame 84 of one of the conveyor units 80 via a plate 92.

[0012] 2. Tensioning mechanism The tension applying mechanism 1 applies tension to a chain member 86 that moves in a circulating manner (circulation). 2 and 3, the tension applying mechanism 1 includes a clutch unit 2 that houses a one-way clutch 21 that allows rotation in one direction around a clutch shaft 23 in a housing 25, an arm 3 that is connected to the clutch shaft 23 of the clutch unit 2 and is rotatable around the clutch shaft 23, and a tension pulley 4 that is rotatably supported on the arm 3 and applies tension to a chain member 86. This allows the arm 3 to rotate in a first direction around the clutch shaft 23. The first direction (rotation direction) is the direction in which the tension pulley 4 applies tension to the chain member 86, and the second direction (locking direction) is the direction in which the tension pulley 4 releases tension from the chain member 86. The housing 25 of the tension applying mechanism 1 or the arm 3 is provided rotatably in a second direction opposite to the first direction with respect to the clutch shaft 23. This allows the arm 3 to rotate in the second direction. Here, the housing 25 is provided on a plate 88, which is a support member that supports the clutch unit 2, so as to be rotatable in the second direction, and the arm 3 is fixed to the clutch shaft 23 so as not to be rotatable around the shaft.

[0013] (1) Clutch unit As shown in (a) of Figure 3, the clutch unit 2 has a clutch shaft 23 rotatably supported by a pair of plates 88, a housing 25 having a through hole in its central axis, and a one-way clutch 21 arranged between the through hole of the housing 25 and the clutch shaft 23. Here, the housing 25 is cylindrical with a cylindrical through hole at the center. The housing 25 is fixed to the one plate 88 by the screw 27 with the end face of the housing 25 abutting against the one plate 88. When viewed from the thickness direction (width direction) of the plate 88, the one plate 88 has an elongated hole 88a penetrating in an arc shape on a circumference centered on the central axis of the clutch shaft 23, as shown in FIG. 2(a). The screw 27 is inserted into the elongated hole 88a, and the threaded portion of the screw 27 is screwed into the threaded hole in the end face of the housing 25. This allows the housing 25 to be fixed to the one plate 88 so as to be rotatable in the second direction. Here, the one plate 88 is a plate located on the outside in the width direction.

[0014] (2) Arm Here, the arm 3 has, for example, a rectangular plate shape. A pair of arms 3 are provided on the outer sides in the thickness direction of the pair of plates 88. The arm 3 has through holes at both ends in the longitudinal direction of the arm 3. A screw 31 is inserted into a through hole on one end of the arm 3 and screws into a threaded hole in the clutch shaft 23 of the clutch unit 2. The arm 3 is fixed to the clutch shaft 23 by the screw 31, and when the screw 31 is loosened, the arm 3 can rotate in the second direction relative to the clutch shaft 23, but the screw 31 in this case fixes the arm 3 so that it cannot rotate relative to the clutch shaft 23. A screw 33 is inserted into a through hole on the other end of the arm 3 and screws into a threaded hole in the fixed shaft 41 of the tension pulley 4. When viewed in the thickness direction (width direction) of the plate 88, each plate 88 has an elongated hole 88b that penetrates in an arc shape on a circumference centered on the central axis of the clutch shaft 23. A fixed shaft 41 for the tension pulley 4 is inserted into the elongated hole 88b. This allows the arm 3 to rotate around the clutch shaft 23 in the first direction. The length of the arc in the elongated hole 88b corresponds to the connection length between the inner link and the outer link of the chain member 86. In order to avoid interference with the screw 96 (see FIG. 2) when the arm 3 moves in the first direction, a cylindrical collar 35 is disposed between the arm 3 and one of the plates 88, as shown in FIG. 3(a). In addition, the screw 96 fixes a guide member 95 for guiding the chain member 86 to the frame 84 to the plate 88, as shown in FIG. 2(b).

[0015] (3) Tension pulley The tension pulley 4 has a fixed shaft 41 that is inserted through the long holes 88b of a pair of plates 88 and fixedly supported by a pair of arms 3, and a tension pulley 43 in which the fixed shaft 41 is arranged in a central through hole and is supported rotatably relative to the fixed shaft 41. As shown in Fig. 2(b), the tension pulley 4 is disposed in the path of the circular movement of the chain member 86. The tension pulley 4 functions as a weight, and is supported so as to be movable in the direction in which gravity acts. As a result, the tension pulley 4 constantly applies tension to the chain member 86.

[0016] 3.Use This will be explained using Figure 4. In Fig. 4, "3A" shows the arm in an initial state, "3B" shows the arm in a state in which the chain member 86 has been stretched due to use, "27A" shows the screw in an initial state, and "27B" shows the state in which the links of the chain member 86 have been pulled out multiple times (four times in this case). (1) Arm In the initial state of use, the arm 3A is located at the end of the long hole 88b of the plate 88 on the second direction (lock direction) side. As the conveying device 7 is used, the chain member 86 stretches and the tension pulley 4 moves downward. As a result, the arm 3 rotates around the central axis O of the clutch shaft 23 in the first direction. Furthermore, as the conveying device 7 is used, the chain member 86 stretches, the tension pulley 4 moves downward, and the arm 3B rotates in the first direction about the central axis O and is positioned at the end of the long hole 88b on the first direction (rotation direction) side. When arm 3B is positioned at the end of long hole 88b in the first direction, the amount of elongation of chain member 86 corresponds to approximately the connection length between the inner link and the outer link. In other words, angle A between the center line of arm 3A and the center line of arm 3B in the figure corresponds to the connection length between the inner link and the outer link. This makes it possible to grasp the amount of elongation of chain member 86 from the position of arm 3.

[0017] (2) Housing In the initial state of use, the housing 25 is fixed by the screw 27A at the end of the long hole 88b of the plate 88 on the first direction (rotation direction) side. As the conveyor 7 is used, when the amount of elongation of the chain member 86 reaches the connecting length between the inner link and the outer link, that is, when the position of the arm 3B reaches the end of the long hole 88b on the first direction side, the link of the chain member 86 is released to shorten the overall length. Accordingly, the screw 27A that fixed the housing 25 to one plate 88 is loosened, and the housing 25 is rotated around the clutch shaft 23 in the second direction. As a result, the arm 3A fixed to the housing 25 returns to the position of the end of the long hole 88b in the second direction. In this manner, the position of the arm 3 can be easily returned to the second direction. At this time, since the connection length of the inner link and the outer link of the chain member 86 corresponds to the length of the long hole 88b, the total length of the chain member 86 with the link removed becomes the same as the total length of the chain member 86 at the start of use, and the position of the arm 3 when returned becomes the end of the long hole 88b in the second direction. Furthermore, as the conveying device 7 is used, the chain member 86 stretches and the links are removed, so that the screw 27 fixing the housing 25 moves in the second direction within the long hole 88a, and eventually the screw 27B is positioned at the end in the second direction. When screw 27B is located at the end of long hole 88a in the second direction, this corresponds to the life of chain member 86. In other words, angle B between an imaginary line connecting central axis O and the center of screw 27A in the figure and an imaginary line connecting central axis O and the center of screw 27B indicates the number of times the links of chain member 86 have been removed. This makes it possible to grasp the life of chain member 86.

[0018] 4.Other (1) In the first embodiment, as shown in (a) of FIG. 3, the housing 25 of the clutch unit 2 was fixed to the plate 88 on the outer side in the width direction by the screws 27. However, it may be fixed to the plate 88 on the inner side in the width direction by the screws. (2) Although the elongated hole 88a of the plate 88 has an arc shape, it may have a shape that covers substantially the entire circumferential area, that is, a shape close to a circle. In this case, it is not necessary to consider the number of times the links are removed until the life of the chain member 86 ends (i.e., the angle at which it is returned in the second direction) shown in Fig. 4. Also, when the elongated hole 88a has an arc shape, a mark indicating the life of the chain member may be provided on the plate. There may be a plurality of long holes 88a, and the length of the arc of one of the long holes may correspond to the life of the chain member 86, while the other long holes may be longer than the long hole associated with the life. (3) In the first embodiment, the long holes 88a of the plate 88 correspond to the connection length between the inner links and the outer links (are set to approximately the same length). In other words, the tension applying mechanism 1 corresponds to the chain member 86 used in the conveying device 7, but, for example, the long holes 88a may be longer than the connection length. Making the long holes 88a longer than the connection length makes it possible to accommodate a plurality of chain members 86 with different connection lengths, thereby improving versatility. (4) Although one screw 31 is used to fix the arm 3 to the clutch shaft 23, for example, as shown in Fig. 7(a), two screws 331 may be used for fixation. This makes it possible to prevent the arm 303 from rotating around the central axis of the clutch shaft even if the screw 331 becomes loose.

[0019] <Second embodiment> In the first embodiment, the housing 25 is provided to be rotatable in the second direction on a plate 88 which is a support member that supports the clutch unit 2, and the arm 3 is provided to the clutch shaft 23 so as not to be rotatable around the shaft. In the second embodiment, the arm 203 is provided rotatably in a second direction relative to the clutch shaft 223, and the housing 225 is provided on a plate 288, which is a support member that supports the clutch unit 202, so as not to be rotatable around the clutch shaft 223. The tension applying mechanism 201 of the second embodiment will be described below with reference to FIGS.

[0020] 1. Configuration The tension applying mechanism 201 includes a clutch unit 202 that houses in a housing 25 a one-way clutch 21 that allows rotation in one direction around a clutch shaft 223, an arm 203 that is connected to the clutch shaft 223 of the clutch unit 2 and is rotatable around the clutch shaft 223, and a tension pulley 4 that is rotatably supported by the arm 203 and applies tension to the chain member 86. Note that the tension pulley 4 has the same or substantially the same structure as in the first embodiment, and therefore a description thereof will be omitted.

[0021] (1) Clutch unit The clutch unit 202 has a clutch shaft 223 rotatably supported by a pair of plates 288, a housing 25 having a through hole in its central axis, and a one-way clutch 21 disposed between the through hole of the housing 25 and the clutch shaft 23. Note that since the clutch unit 2 has the same or substantially the same structure as the clutch unit 2 of the first embodiment except for the length of the clutch shaft 223, a description of the one-way clutch 21 and the housing 25 will be omitted. The housing 25 is fixed to the plate 288 by the screw 27 with its end face abutting against the plate 288. The plate 288 is provided with a through hole through which the screw 27 passes, and when viewed from the thickness direction (width direction) of the plate 288, the through hole has a shape and size corresponding to the threaded portion of the screw 27. In other words, the housing 25 is fixed to the plate 288 so as not to rotate. Note that the plate 288 to which the housing 25 is fixed is a plate located on the outside in the width direction here, but it may be a plate located on the inside.

[0022] (2) Arm Here, the arm 203 has, for example, a rectangular plate shape. A pair of arms 203 are provided on the outer sides in the thickness direction of the pair of plates 288. The arm 203 has through holes at both ends in the longitudinal direction of the arm 203. 5(b), the clutch shaft 223 is inserted into the through hole 203a on one end side of the arm 203. The screw 33 is inserted into the through hole (not shown in the figure due to the screw 33) on the other end side of the arm 3, as in the first embodiment, and is screwed into the screw hole of the fixed shaft 41 of the tension pulley 4. Similarly to the first embodiment, each plate 288 is provided with an elongated hole 88b. Similarly to the first embodiment, the length of the arc in the elongated hole 88b corresponds to the connection length between the inner link and the outer link of the chain member 86. Additionally, a collar 35 is provided to avoid interference between the arm 203 and the screw 96 (not visible in FIG. 5 due to the arm 203) that fixes the guide member 95.

[0023] As described above, the arm 203 is rotatable with respect to the clutch shaft 223, and is normally fixed to the clutch shaft 223 so as not to rotate. The arm 203 is attached (fixed) to the clutch shaft 223 by fixing the clamping means 205, which clamps the clutch shaft 223 so as not to rotate, to the arm 203. The clamping means 205 has a plurality of clamping members 251 formed by dividing a member that fits onto the outer periphery of the columnar (including cylindrical) clutch shaft 223, and is connected by a connector (e.g., a screw) 253 in a state where the plurality of clamping members 251 clamp the clutch shaft 223. Specifically, a set collar can be used as the clamping means 205. Here, it is a separate type in which two collars 251 are separated. The set collar 205 is fixed to the arm 203 by screwing a screw 259 passing through a through hole 251a on the side of the collar 251 into a screw hole 203b of the arm 203.

[0024] 2.Use In the initial state of use, the arm 203 is located at the end of the long hole 288b in the second direction (locking direction) of the plate 288. As the conveying device is used, the chain member 86 stretches and when the arm 203 is located at the end of the long hole 288b in the first direction (rotation direction), the links of the chain member 86 are released to shorten the overall length of the chain member 86. Accordingly, the screw 259 and the connector 253 of the set collar 205 that fixes the arm 203 to the clutch shaft 223 are loosened, and the arm 203 is rotated in the second direction around the clutch shaft 223. Then, the screw 259 and the connector 253 of the set collar 205 are tightened again to fix the arm 203 so that it does not rotate relative to the clutch shaft 223.

[0025] 3.Other (1) In the second embodiment, as shown in Fig. 6, the housing 25 of the clutch unit 202 is fixed to the plate 288 on the outer side in the width direction by the screw 27, but it may be fixed to the plate 288 on the inner side in the width direction by the screw, or may be fixed to a pair of plates 288. Note that the term "fixed" here means fixed so as not to rotate about the central axis of the clutch shaft 223. (2) The housing 25 is fixed to the plate 288 by the screw 27, but for example, the housing may be supported in such a manner that the protrusions or recesses of the pair of plates are fitted into the recesses or protrusions of the housing. In this case as well, the housing is supported (fixed) so as not to rotate about the central axis of the clutch shaft. (3) Although a separate type set collar 205 is used to fix the clutch shaft 223 of the arm 203, other types of set collars may be used, such as a setscrew type, a slit type, a hinge type, etc. Also, for example, in the case of a setscrew type, the set collar may be integrated with the arm.

[0026] <Modification> The tension applying mechanisms 1, 201 according to the first and second embodiments have been described above, but the present invention is not limited to these embodiments and may be modified in the following ways. The present invention may also be modified in a combination of the embodiments and modifications, or in a combination of modifications. The present invention also includes examples not described in the embodiments and modifications, and design changes that do not depart from the gist of the present invention.

[0027] 1.Endless member In the embodiment, a chain member 86 formed by connecting an inner link and an outer link is used as the endless member, but a belt member without a link mechanism can also be used. When a belt member is used, for example, when the arm 3, 203 moves from the end on the second direction side of the long holes 88b, 288b of the plates 88, 288 to the end on the first direction side to replace the belt member, the arm 3, 203 can be easily rotated in the second direction. Also, when a belt member is used, the length of the arc of the long holes 88b, 288b corresponds to the amount of stretch of the belt member at the time of replacement, so that the time to replace the belt member can be known.

[0028] 2. Tensioning mechanism (1) Tension pulley The tension pulley 4 applies a load to the endless member 86 by its own weight, but a weight may be added, or a biasing means such as a spring may be added. (2) Arm In the embodiment, there is a pair of arms 3, 203, but depending on the size of the tension pulley and the magnitude of the tension applied to the endless member, there may be only one arm. The shape of the arm is rectangular when viewed from the extension direction of the clutch shaft, but it may be other shapes such as an arc shape or an "L" shape as shown in Figure 7(b). (3) Fixing the arm to the tension pulley In the embodiment, one screw 33 is used to fix the arm 3, 203 to the tension pulley 4, but for example, as shown in FIG. 7, the arms 303, 403 may be fixed with two screws 333. Furthermore, in the first embodiment, the arm 3 is fixed to the clutch shaft 23 by one screw 31, but as shown in FIG. 7(a), the arm 303 may be fixed by two screws 331.

[0029] (4) Other functions The tension applying mechanism may have other functions. As shown in (a) and (b) of Figure 7, the tension applying mechanism may include a sensor 61 that detects when the movement of the arm 303, 403 in the first direction reaches a predetermined position. The predetermined position here is a position where the arm 303, 403 reaches the end of the long hole 388b, 488b in the first direction. The sensor 61 may be a non-contact type or a contact type, and a non-contact type proximity sensor can be used here. The sensor 61 is provided on the plate 388, 488, and detects the sensor dog 63 attached to the arm 303, 403. Needless to say, the sensor 61 also includes a notification means for notifying the user when the sensor 61 detects the sensor dog 63. This makes it possible to prevent the arm 303, 403 from being left in a state where it has reached the end of the long hole 388b, 488b in the first direction for a long period of time. [Explanation of symbols]

[0030] 1 Tensioning mechanism 2 Clutch unit 3 Arm 4 Tension pulley 7. Conveyor 21 One-way clutch 23 Clutch shaft 25 Housing 61 Sensors 86 Chain components (endless components) 88 Plate (support member)

Claims

1. In a tension applying mechanism for an endless member that moves in a circulating manner, a clutch unit that accommodates a one-way clutch in a housing, the one-way clutch allowing rotation in one direction around a clutch shaft; an arm connected to the clutch shaft of the clutch unit and rotatable about the clutch shaft; a tension pulley rotatably supported on the arm and configured to apply tension to the endless member; Equipped with The housing or the arm is provided rotatably relative to the clutch shaft in a second direction opposite to the first direction, The arm is provided on the clutch shaft so as to be rotatable in the second direction, The housing is attached to a support member that supports the clutch unit so as not to be rotatable around the clutch shaft. Tensioning mechanism.

2. A sensor is provided to detect when the movement of the arm in the first direction reaches a predetermined position. The tensioning mechanism of claim 1 .

3. The tension pulley is provided with a weight or a biasing means.

3. A tensioning mechanism according to claim 1 or 2.

4. A conveying device that utilizes an endless member and conveys a conveyed object; a tension applying mechanism that applies tension to the endless member; Equipped with The tension applying mechanism is a tension applying mechanism according to any one of claims 1 to 3. A transport device with a tension mechanism.

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