attachment

Abstract

To suppress prolongation of work time in a construction site.SOLUTION: An attachment includes: an input shaft that is rotatable with a first rotary shaft as a center and to which power is input from an electric tool; a tip socket having a recess; a housing that has a housing opening to which a work object is inserted, and rotatably supports the tip socket; a power transmission mechanism for transmitting power input to the input shaft, to the tip socket; and a front face stop mechanism for stopping rotation of the tip socket in a state in which the socket opening of the recess and the housing opening are made coincident with each other.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The technology disclosed in this specification relates to an attachment.

Background Art

[0002] At a construction site, fixtures such as floor ties or turnbuckles are used. Patent Document 1 discloses a tool for a turnbuckle for adjusting the length of the turnbuckle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Floor ties support the large pulls of a building. At a construction site, an operation for adjusting the length of the floor ties is carried out. A technology that can suppress the lengthening of the working time at the construction site is desired.

[0005] The technology disclosed in this specification aims to suppress the lengthening of the working time at a construction site.

Means for Solving the Problems

[0006] This specification discloses an attachment to be mounted on a power tool. The attachment may include a power input shaft that is rotatable about a first rotation axis and receives power from the power tool, a tip socket having a recess, a housing having a housing opening into which a work object is inserted, and rotatably supports the tip socket, a power transmission mechanism that transmits the power input to the input shaft to the tip socket, and a front stop mechanism that stops the rotation of the tip socket in a state where the socket opening of the recess and the housing opening are aligned.

Effects of the Invention

[0007] The technology disclosed herein helps to suppress the prolongation of working hours at construction sites. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram illustrating how to use the attachment according to the embodiment. [Figure 2] Figure 2 is a perspective view from the right rear showing the attachment according to the embodiment. [Figure 3] Figure 3 is a perspective view from the front left showing the attachment according to the embodiment. [Figure 4] Figure 4 is an exploded perspective view from the right rear showing the attachment according to the embodiment. [Figure 5] Figure 5 is an exploded perspective view from the front left showing the attachment according to the embodiment. [Figure 6] Figure 6 is a cross-sectional view showing an attachment according to an embodiment. [Figure 7] Figure 7 is a bottom perspective view showing the input shaft, tip socket, power transmission mechanism, power cutoff mechanism, front stop mechanism, and magnet according to the embodiment. [Figure 8] Figure 8 is a top-down perspective view showing the input shaft, tip socket, power transmission mechanism, power cutoff mechanism, front stop mechanism, and magnet according to the embodiment. [Figure 9] Figure 9 is a bottom view showing the input shaft, tip socket, power transmission mechanism, power cutoff mechanism, front stop mechanism, and magnet according to the embodiment. [Figure 10] Figure 10 is a front view showing the input shaft, tip socket, power transmission mechanism, power cutoff mechanism, front stop mechanism, and magnet according to the embodiment. [Figure 11] Figure 11 is an exploded perspective view from the front right showing a part of the input shaft and power transmission mechanism according to the embodiment. [Figure 12] Figure 12 is a cross-sectional view showing the operation of the attachment according to the embodiment. [Figure 13] Figure 13 is a bottom view showing the operation of the input shaft, tip socket, power transmission mechanism, power cutoff mechanism, front stop mechanism, and magnet. [Modes for carrying out the invention]

[0009] In one or more embodiments, the attachment may include an input shaft rotatable about a first rotation axis and receiving power from a power tool; a tip socket having a recess; a housing having a housing opening into which a workpiece is inserted and rotatably supporting the tip socket; a power transmission mechanism for transmitting power input to the input shaft to the tip socket; and a front stop mechanism for stopping the rotation of the tip socket when the socket opening in the recess aligns with the housing opening.

[0010] In the above configuration, when the workpiece is a bundle body, the bundle body is inserted into the recess of the tip socket through the housing opening and the socket opening. Power is applied to the input shaft, causing the tip socket to rotate. The rotation of the tip socket causes the bundle body to rotate. The rotation of the bundle body adjusts the length of the floor bundle. After the length of the floor bundle has been adjusted, the rotation of the tip socket stops when the socket opening and the housing opening are aligned, due to the operation of the front stop mechanism. This allows the worker to immediately remove the attachment from the bundle body. Since the attachment can be immediately removed from the bundle body after the work of adjusting the length of the floor bundle is completed, the work time is kept from being prolonged.

[0011] In one or more embodiments, the attachment may include a power cut-off mechanism capable of cutting off power. A front stop mechanism may, in synchronization with the power cut-off, stop the rotation of the tip socket while aligning the socket opening of the recess with the housing opening.

[0012] In the above configuration, after the adjustment of the length of the floor bundle is completed, by operating the power cut-off mechanism and the front stop mechanism in synchronization, when the rotation of the tip socket stops, the reaction torque applied to the operator from the attachment is reduced.

[0013] In one or more embodiments, the power transmission mechanism may include a missing-tooth gear provided on the outer peripheral surface of the tip socket, and a spur gear coupled to the missing-tooth gear and having the same number of teeth as the missing-tooth gear. The front stop mechanism may include a rotating member fixed to the spur gear and having a notch, and a moving member inserted into the notch in synchronization with the power cut-off.

[0014] In the above configuration, when the moving member is inserted into the notch, the rotation of the spur gear stops. Since the number of teeth of the missing-tooth gear is the same as the number of teeth of the spur gear, when the rotation of the spur gear stops, the rotation of the missing-tooth gear stops so that the socket opening and the housing opening coincide.

[0015] In one or more embodiments, the power transmission mechanism may include a first intermediate shaft connected to the input shaft and rotating together with the input shaft, and a second intermediate shaft spline-coupled to the first intermediate shaft and transmitting the power input to the input shaft to the spur gear. The power cut-off mechanism may release the spline connection.

[0016] In the above configuration, when the spline connection is released, the power transmitted from the input shaft to the tip socket is cut off.

[0017] In one or more embodiments, the attachment may be supported by the housing and include a bearing that supports the first intermediate shaft. The input shaft and the first intermediate shaft may be movable in the front-rear direction parallel to the first rotation axis. The spline connection may be released by the forward movement of the input shaft and the first intermediate shaft.

[0018] In the above configuration, the power tool is pushed forward by the operator, causing the input shaft and the first intermediate shaft to move forward. This releases the spline connection.

[0019] In one or more embodiments, the moving member may move in the longitudinal direction together with the input shaft and the first intermediate shaft. The moving member may be inserted into the notch as the input shaft and the first intermediate shaft move forward.

[0020] In the above configuration, the power tool is pushed forward by the operator, causing the input shaft and the first intermediate shaft to move forward. This causes the moving member to be inserted into the notch, and the rotation of the toothless gear stops so that the socket opening and the housing opening align.

[0021] In one or more embodiments, the power transmission mechanism may have a first intermediate gear and a second intermediate gear that mesh with a spur gear. The spur gear may be coupled to a gear with missing teeth via at least one of the first intermediate gear and the second intermediate gear. During the rotation of the spur gear, at least one of the first intermediate gear and the second intermediate gear may mesh with the gear with missing teeth.

[0022] In the above configuration, during the rotation of the missing gear, when the missing gear and the first intermediate gear cannot mesh, the missing gear meshes with the second intermediate gear. Therefore, the rotational force of the spur gear is transmitted to the missing gear via the second intermediate gear. Similarly, when the missing gear and the second intermediate gear cannot mesh, the missing gear meshes with the first intermediate gear. Therefore, the rotational force of the spur gear is transmitted to the missing gear via the first intermediate gear.

[0023] In one or more embodiments, the attachment may include a magnet positioned on the inner surface of the recess.

[0024] In the above configuration, the bundle body is attracted to the inner surface of the recess. This prevents the tip socket from rotating while the central axis of the bundle body and the second rotation axis of the tip socket are misaligned. Therefore, the attachment can rotate the bundle body stably.

[0025] In one or more embodiments, the inner surface of the recess may include a first surface and a second surface facing the first surface with a gap between them. The socket opening may be provided between one end of the first surface and one end of the second surface. The surface of the magnet may be positioned between the other end of the first surface and the other end of the second surface.

[0026] In the above configuration, since the magnet is positioned on the back surface of the recess, when the bundle body is inserted into the recess through the socket opening, the bundle body is prevented from being attracted to at least one of the first and second sides. The bundle body is attracted to the magnet after being inserted all the way to the back of the recess, thus preventing a decrease in workability when inserting the bundle body into the tip socket.

[0027] The first side, second side, and back surface may each be parallel to the second rotation axis of the tip socket. The dimensions of the first side, second side, and back surface in the direction parallel to the second rotation axis may be larger than the dimensions of the first side, second side, and back surface in the direction perpendicular to the second rotation axis.

[0028] In the above configuration, rotation of the tip socket is prevented when the central axis of the bundle body and the second rotation axis of the tip socket are misaligned. Therefore, the attachment can rotate the bundle body stably.

[0029] The embodiments will be described below with reference to the drawings. The components of the embodiments described below can be combined as appropriate. In addition, some components may be omitted.

[0030] In the embodiments, the terms left, right, front, rear, top, and bottom are used to describe the positional relationships of each part. These terms indicate relative positions or directions with respect to the center of the attachment.

[0031] [How to use the attachment] Figure 1 is a schematic diagram illustrating how to use attachment 1 according to an embodiment. Attachment 1 is mounted on a power tool 100. In the example shown in Figure 1, the power tool 100 is a pen-type driver drill. Note that the power tool 100 may be any rotary power tool such as an impact driver or a driver drill. The power tool 100 comprises an output shaft 101 and a motor (not shown) that rotates the output shaft 101. The output shaft 101 has a tool hole 102 into which a driver bit is inserted. When the operator operates the trigger switch provided on the power tool 100, the motor is driven and the output shaft 101 rotates.

[0032] Attachment 1 is used to adjust the length of the floor joist 200. Examples of floor joists 200 include resin joists made of synthetic resin or steel joists made of steel. In this embodiment, the floor joist 200 is a steel joist. In the following description, the floor joist 200 will be referred to as a steel joist 200 as appropriate.

[0033] The steel support 200 is installed on the foundation 301 of the building. The steel support 200 supports the main beam 302 of the building from below. The steel support 200 comprises a support body 201 extending in the vertical direction, a lower threaded rod 202 attached to the lower part of the support body 201, an upper threaded rod 203 attached to the upper part of the support body 201, a base plate 204 fixed to the lower threaded rod 202, and a support plate 205 fixed to the upper threaded rod 203.

[0034] The bundle body 201 is pipe-shaped. The middle section of the bundle body 201 in the vertical direction is rectangular. That is, the outer shape of the middle section of the bundle body 201 in the vertical direction is square. A lower screw hole is provided at the bottom of the bundle body 201. An upper screw hole is provided at the top of the bundle body 201. The lower screw hole and the upper screw hole have reverse threads relative to each other.

[0035] The lower threaded rod 202 is inserted into the lower threaded hole of the bundle body 201 from the bottom of the bundle body 201. The lower threaded rod 202 is connected to the lower threaded hole. The upper threaded rod 203 is inserted into the upper threaded hole of the bundle body 201 from the top of the bundle body 201. The upper threaded rod 203 is connected to the upper threaded hole.

[0036] The base plate 204 is fixed to the lower end of the lower threaded rod 202. The base plate 204 is installed on the foundation 301. The support plate 205 is fixed to the upper end of the upper threaded rod 203. The support plate 205 supports the main beam 302.

[0037] As the bundle body 201 is rotated, the insertion depth of the lower threaded rod 202 into the lower threaded hole and the insertion depth of the upper threaded rod 203 into the upper threaded hole change. As a result of these changes, the distance between the base plate 204 and the support plate 205 changes. This adjusts the length of the steel bundle 200 and the height of the support plate 205 relative to the base plate 204.

[0038] A lower lock nut 206 is positioned around the lower threaded rod 202. An upper lock nut 207 is positioned around the upper threaded rod 203. After the length of the steel support 200 is adjusted, the lower lock nut 206 is rotated relative to the lower threaded rod 202 so that the lower lock nut 206 contacts the support body 201, and the upper lock nut 207 is rotated relative to the upper threaded rod 203 so that the upper lock nut 207 contacts the support body 201. This suppresses the relative rotation between the support body 201 and the lower threaded rod 202, and suppresses the relative rotation between the support body 201 and the upper threaded rod 203.

[0039] Attachment 1 comprises an input shaft 3 inserted into the tool hole 102 of the power tool 100 and a tip socket 4 positioned around the bundle body 201. The input shaft 3 rotates around the rotation axis AX (first rotation axis). The tip socket 4 rotates around the rotation axis CX (second rotation axis). The axis parallel to the rotation axis AX and the rotation axis CX are perpendicular. With the input shaft 3 inserted into the tool hole 102 and the tip socket 4 positioned around the bundle body 201, the motor is driven and the output shaft 101 rotates when the trigger switch on the power tool 100 is operated by the operator. As the output shaft 101 rotates, power is input from the power tool 100 to the input shaft 3. As the output shaft 101 rotates, the input shaft 3 rotates around the rotation axis AX. As the input shaft 3 rotates, the tip socket 4 rotates around the rotation axis CX. As the tip socket 4 rotates, the bundle body 201 rotates. The length of the steel beam 200 is adjusted by the rotation of the beam body 201.

[0040] [attachment] Figure 2 is a rear-right perspective view showing attachment 1 according to the embodiment. Figure 3 is a front-left perspective view showing attachment 1 according to the embodiment. Figure 4 is an exploded rear-right perspective view showing attachment 1 according to the embodiment. Figure 5 is an exploded front-left perspective view showing attachment 1 according to the embodiment. Figure 6 is a cross-sectional view showing attachment 1 according to the embodiment.

[0041] Attachment 1 comprises a housing 2, an input shaft 3, a tip socket 4, a power transmission mechanism 5, a power cut-off mechanism 6, a front stop mechanism 7, and a magnet 8.

[0042] Housing 2 houses the power transmission mechanism 5, the power cut-off mechanism 6, and the front stop mechanism 7. Housing 2 has a housing opening 2M into which the bundle body 201, which is the workpiece, is inserted. Housing 2 includes a lower housing 2A, an upper housing 2B, and a rear housing 2C.

[0043] The input shaft 3 is positioned behind the rear housing 2C. The input shaft 3 is positioned to extend in the front-to-back direction. When inserted into the tool hole 102 of the power tool 100, the input shaft 3 is rotatable around the rotation axis AX. The rotation axis AX extends in the front-to-back direction.

[0044] The tip socket 4 is positioned at the front end of the housing 2. The tip socket 4 has a socket opening 4M into which the bundle body 201 is inserted. The tip socket 4 has a recess 4R into which the bundle body 201 is positioned. The socket opening 4M is provided at the front end of the recess 4R. While positioned around the bundle body 201, it rotates around the rotation axis CX. The rotation axis CX extends in the vertical direction.

[0045] Figure 7 is a bottom perspective view showing the input shaft 3, tip socket 4, power transmission mechanism 5, power cut-off mechanism 6, front stop mechanism 7, and magnet 8 according to the embodiment. Figure 8 is a top perspective view showing the input shaft 3, tip socket 4, power transmission mechanism 5, power cut-off mechanism 6, front stop mechanism 7, and magnet 8 according to the embodiment. Figure 9 is a bottom view showing the input shaft 3, tip socket 4, power transmission mechanism 5, power cut-off mechanism 6, front stop mechanism 7, and magnet 8 according to the embodiment. Figure 10 is a front view showing the input shaft 3, tip socket 4, power transmission mechanism 5, power cut-off mechanism 6, front stop mechanism 7, and magnet 8 according to the embodiment. Figure 11 is an exploded perspective view from the front right showing a part of the input shaft 3 and power transmission mechanism 5 according to the embodiment.

[0046] The power transmission mechanism 5 transmits the power input from the power tool 100 to the input shaft 3 to the tip socket 4. The power transmission mechanism 5 transmits the rotational force of the input shaft 3 to the tip socket 4. The power transmission mechanism 5 includes a first intermediate shaft 9, a second intermediate shaft 10, a first bevel gear 11, a second bevel gear 12, a third intermediate shaft 24, a spur gear 13, a first intermediate gear 14, a second intermediate gear 15, and a toothless gear 16.

[0047] The first intermediate shaft 9 is connected to the input shaft 3. The first intermediate shaft 9 rotates together with the input shaft 3 around the axis of rotation AX. The first intermediate shaft 9 and the input shaft 3 are connected by two balls 17 and a leaf spring 18. The balls 17 are positioned in grooves 3A provided at the front of the input shaft 3. The leaf spring 18 is positioned to cover the balls 17. The leaf spring 18 has an opening 18A into which a portion of the balls 17 are positioned.

[0048] The first intermediate shaft 9 is rotatably supported by a bearing 19. The bearing 19 is a sliding bearing. The bearing 19 is held in the cylindrical portion 2D of the rear housing 2C. The input shaft 3 is supported by the housing 2 via the first intermediate shaft 9 and the bearing 19, which is a sliding bearing. The rear housing 2C has a support portion 2E that contacts the rear end of the bearing 19 and a support portion 2F that contacts the front end of the bearing 19. The support portions 2E and 2F prevent the bearing 19 from moving in the front-rear direction relative to the housing 2. The first intermediate shaft 9 is rotatably supported by the bearing 19 about the rotation axis AX and is movable in the front-rear direction relative to the bearing 19. The input shaft 3 and the first intermediate shaft 9 are supported by the housing 2 via the bearing 19 so as to be movable in the front-rear direction parallel to the rotation axis AX.

[0049] The second intermediate shaft 10 is connected to the first intermediate shaft 9. The second intermediate shaft 10 transmits power input from the power tool 100 to the input shaft 3 to the spur gear 13. The second intermediate shaft 10 is spline-coupled to the first intermediate shaft 9. The first intermediate shaft 9 has a spline hole 9A into which the rear part of the second intermediate shaft 10 is inserted. Spline internal teeth 9G are formed on the inner surface of the spline hole 9A. Spline external teeth 10G are formed on the rear part of the second intermediate shaft 10. The spline internal teeth 9G and the spline external teeth 10G mesh together. With the spline internal teeth 9G and the spline external teeth 10G meshed together, the second intermediate shaft 10 rotates together with the first intermediate shaft 9 around the rotation axis AX.

[0050] The second intermediate shaft 10 is rotatably supported by bearings 20. The bearings 20 are ball bearings. Two bearings 20 are arranged. The two bearings 20 are arranged in the front-rear direction. The rear end face of the outer ring of the rear bearing 20 is supported by a support portion 2G provided in the lower housing 2A via a snap ring 21. The front end face of the outer ring of the front bearing 20 is supported by a support portion 2H provided in the lower housing 2A. The front end face of the inner ring of the front bearing 20 is supported by a snap ring 22. The snap ring 22 is located in a groove 10A provided in the front of the second intermediate shaft 10. The support portions 2G and 2H prevent the bearings 20 from moving in the front-rear direction relative to the housing 2.

[0051] The second intermediate shaft 10 has a flange portion 10B that contacts the rear end surface of the inner ring of the rear bearing 20. The flange portion 10B and the snap ring 22 prevent the second intermediate shaft 10 from moving in the front-rear direction relative to the bearing 20.

[0052] As described above, the first intermediate shaft 9 is movable in the front-rear direction relative to the bearing 19. From a state where the internal spline teeth 9G and the external spline teeth 10G are engaged, the first intermediate shaft 9 can be moved forward relative to the bearing 19. When the first intermediate shaft 9 moves forward, the internal spline teeth 9G separate from the external spline teeth 10G. In other words, when the first intermediate shaft 9 moves forward, the spline connection between the internal spline teeth 9G and the external spline teeth 10G is released.

[0053] A coil spring 23 is positioned in the internal space 9B of the first intermediate shaft 9. The rear end of the coil spring 23 contacts a support surface 9C provided in the internal space 9B of the first intermediate shaft 9. The front end of the coil spring 23 contacts a support surface 10C provided on the second intermediate shaft 10. The coil spring 23 is positioned between the support surfaces 9C and 10C in a compressed state. The coil spring 23 generates an elastic force that moves the first intermediate shaft 9 backward.

[0054] The first bevel gear 11 is fixed to the front end of the second intermediate shaft 10. The first bevel gear 11 rotates together with the second intermediate shaft 10 around the rotation axis AX.

[0055] The second bevel gear 12 meshes with the first bevel gear 11. The second bevel gear 12 rotates around the rotation axis BX. The rotation axis BX extends vertically. The second bevel gear 12 is fixed to the third intermediate shaft 24. The third intermediate shaft 24 extends vertically. The third intermediate shaft 24 rotates together with the second bevel gear 12 around the rotation axis BX. The lower end of the third intermediate shaft 24 is rotatably supported by a bearing 25. The upper end of the third intermediate shaft 24 is rotatably supported by a bearing 26. The bearing 25 is held in the lower housing 2A. The bearing 26 is held in the upper housing 2B. When the first bevel gear 11 rotates, the second bevel gear 12 rotates. When the second bevel gear 12 rotates, the third intermediate shaft 24 rotates together with the second bevel gear 12.

[0056] The spur gear 13 is fixed to the third intermediate shaft 24. The spur gear 13 is positioned below the second bevel gear 12. The spur gear 13 rotates around the rotation axis BX. When the second bevel gear 12 rotates and the third intermediate shaft 24 rotates, the spur gear 13 rotates together with the third intermediate shaft 24.

[0057] The first intermediate gear 14 and the second intermediate gear 15 each mesh with the spur gear 13. The first intermediate gear 14 is positioned to the right of the second intermediate gear 15. The first intermediate gear 14 and the second intermediate gear 15 each rotate around a vertically extending axis. A shaft 14A is fixed to the first intermediate gear 14. A shaft 15A is fixed to the second intermediate gear 15. The lower end of the shaft 14A is rotatably supported by a bearing 27, and the upper end of the shaft 14A is rotatably supported by a bearing 28. The lower end of the shaft 15A is rotatably supported by a bearing 29, and the upper end of the shaft 15A is rotatably supported by a bearing 30. Bearings 27 and 29 are each held in the lower housing 2A. Bearings 28 and 30 are each held in the upper housing 2B.

[0058] As the spur gear 13 rotates, the first intermediate gear 14 and the second intermediate gear 15, which are meshed with the spur gear 13, also rotate.

[0059] The missing tooth gear 16 is provided on the outer circumferential surface of the tip socket 4. The missing tooth gear 16 is fixed to the tip socket 4. The missing tooth gear 16 and the tip socket 4 may be a single unit. The missing tooth gear 16 meshes with at least one of the first intermediate gear 14 and the second intermediate gear 15. The spur gear 13 is coupled to the missing tooth gear 16 via at least one of the first intermediate gear 14 and the second intermediate gear 15. The missing tooth gear 16 has a gear opening 16M into which the bundle body 201 is inserted. In the circumferential direction of the rotation axis CX, the socket opening 4M and the gear opening 16M coincide.

[0060] The rotation of the first intermediate gear 14 and the second intermediate gear 15 causes the missing tooth gear 16 to rotate around the rotation axis CX. As the missing tooth gear 16 rotates, the tip socket 4 fixed to the missing tooth gear 16 rotates together with the missing tooth gear 16 around the rotation axis CX.

[0061] The missing tooth gear 16 has a gear opening 16M. Therefore, during the rotation of the missing tooth gear 16, there is a period during which the missing tooth gear 16 and the first intermediate gear 14 cannot mesh. During this period, the missing tooth gear 16 meshes with the second intermediate gear 15. Therefore, the rotational force of the spur gear 13 is transmitted to the missing tooth gear 16 via the second intermediate gear 15. Similarly, during the rotation of the missing tooth gear 16, there is a period during which the missing tooth gear 16 and the second intermediate gear 15 cannot mesh. During this period, the missing tooth gear 16 meshes with the first intermediate gear 14. Therefore, the rotational force of the spur gear 13 is transmitted to the missing tooth gear 16 via the first intermediate gear 14. As the spur gear 13 rotates, at least one of the first intermediate gear 14 and the second intermediate gear 15 meshes with the toothless gear 16, so the rotational force of the spur gear 13 is transmitted to the toothless gear 16.

[0062] The tip socket 4 is rotatably supported by bearings 31 and 32. Bearing 31 rotatably supports the lower part of the tip socket 4. Bearing 32 rotatably supports the upper part of the tip socket 4. Bearing 31 is held in the lower housing 2A. Bearing 32 is held in the upper housing 2B. The tip socket 4 is rotatably supported in the housing 2 via bearings 31 and 32.

[0063] A portion of bearing 31 is notched. Bearing 31 has a bearing opening 31M into which the bundle body 201 is inserted. A portion of bearing 32 is notched. Bearing 32 has a bearing opening 32M into which the bundle body 201 is inserted.

[0064] The power interruption mechanism 6 can interrupt the power transmitted from the input shaft 3 to the tip socket 4. The power interruption mechanism 6 includes internal spline teeth 9G and external spline teeth 10G. By disengaging the spline coupling between the first intermediate shaft 9 and the second intermediate shaft 10, the power transmitted from the input shaft 3 to the tip socket 4 is interrupted. When the input shaft 3 and the first intermediate shaft 9 are rotated by the power tool 100 with the internal spline teeth 9G and the external spline teeth 10G engaged, the second intermediate shaft 10 rotates together with the first intermediate shaft 9. As a result, the rotational force input to the input shaft 3 is transmitted to the tip socket 4 via the power transmission mechanism 5. The operator can move the power tool 100 forward so as to press the power tool 100 against the attachment 1 with the input shaft 3 inserted into the tool hole 102 and the tip socket 4 positioned around the bundle body 201. As described above, the first intermediate shaft 9 is movable in the front-rear direction relative to the bearing 19. As the power tool 100 moves forward so as to press against the attachment 1, the input shaft 3 and the first intermediate shaft 9 move forward relative to the bearing 19. When the first intermediate shaft 9 moves forward relative to the bearing 19 from a state where the internal spline teeth 9G and the external spline teeth 10G are engaged, the internal spline teeth 9G move forward of the external spline teeth 10G, and the spline connection between the internal spline teeth 9G and the external spline teeth 10G is released. In other words, the forward movement of the input shaft 3 and the first intermediate shaft 9 releases the spline connection between the first intermediate shaft 9 and the second intermediate shaft 10. As a result, even if the input shaft 3 and the first intermediate shaft 9 are rotated by the power tool 100, the second intermediate shaft 10 does not rotate. Therefore, the transmission of the rotational force input to the input shaft 3 to the tip socket 4 is interrupted.

[0065] The front stopping mechanism 7 stops the rotation of the tip socket 4 when the socket opening 4M of the recess 4R and the housing opening 2M are aligned. The front stopping mechanism 7 adjusts the position of the tip socket 4 in the circumferential direction around the rotation axis CX so that the socket opening 4M of the recess 4R and the housing opening 2M are aligned.

[0066] The front stop mechanism 7 stops the rotation of the tip socket 4 in a state where the socket opening 4M of the recess 4R and the housing opening 2M are aligned, in synchronization with the power cut-off mechanism 6. The front stop mechanism 7 adjusts the position of the tip socket 4 in the circumferential direction around the rotation axis CX so that the socket opening 4M of the recess 4R and the housing opening 2M are aligned when the power transmission is cut off by the power cut-off mechanism 6.

[0067] The front stop mechanism 7 includes a rotating member 33 fixed to the spur gear 13 and a movable member 34 that moves in the front-rear direction together with the input shaft 3 and the first intermediate shaft 9.

[0068] The rotating member 33 is substantially a disc-shaped member. The rotating member 33 is positioned below the spur gear 13. The rotating member 33 is also fixed to the third intermediate shaft 24. The rotating member 33 and the spur gear 13 may be a single unit. The rotating member 33 rotates together with the third intermediate shaft 24 and the spur gear 13 around the rotation axis CX.

[0069] The rotating member 33 has an outer circumferential surface 331 and a notch 332 provided in a part of the outer circumferential surface 331. The notch 332 is formed to be recessed from a part of the outer circumferential surface 331 toward the center of the rotating member 33 (rotation axis CX).

[0070] The inner surface of the notch 332 includes a first side surface 332A, a second side surface 332B facing the first side surface 332A, a contact surface 332C arranged to connect the inner end of the first side surface 332A and the inner end of the second side surface 332B, a first tapered surface 332D arranged to connect the outer end of the first side surface 332A and the outer peripheral surface 331, and a second tapered surface 332E arranged to connect the outer end of the second side surface 332B and the outer peripheral surface 331.

[0071] The movable member 34 is a rod-shaped member that is long in the front-rear direction. The front end of the movable member 34 is positioned in front of the front end of the first intermediate shaft 9. The movable member 34 is connected to the first intermediate shaft 9 via a connecting member 35. In this embodiment, the connecting member 35 is a plate-shaped member. The movable member 34 and the connecting member 35 are fixed together by a screw 36. An arc-shaped portion 35A is provided at the upper end of the connecting member 35. The arc-shaped portion 35A is provided so as to be recessed downward from the upper end of the connecting member 35. The arc-shaped portion 35A is inserted into a groove 9D provided at the front of the outer circumferential surface of the first intermediate shaft 9.

[0072] The relative position between the first intermediate shaft 9 and the movable member 34 does not change. The movable member 34 moves in the front-rear direction together with the input shaft 3 and the first intermediate shaft 9. When the input shaft 3 and the first intermediate shaft 9 move forward, the movable member 34 moves forward together with the input shaft 3 and the first intermediate shaft 9. When the input shaft 3 and the first intermediate shaft 9 move backward, the movable member 34 moves backward together with the input shaft 3 and the first intermediate shaft 9. The lower housing 2A has a guide hole 2K in which the movable member 34 is positioned. The movable member 34 moves in the front-rear direction while being guided by the guide hole 2K.

[0073] As the input shaft 3 and the first intermediate shaft 9 move forward, the front end of the moving member 34 is inserted into the notch 332 of the rotating member 33. The front end of the moving member 34 is inserted into the notch 332 of the rotating member 33 in synchronization with the power cutoff by the power cutoff mechanism 6.

[0074] As described above, with the input shaft 3 inserted into the tool hole 102 and the tip socket 4 positioned around the bundle body 201, the worker can move the power tool 100 forward so as to press the power tool 100 against the attachment 1. During the rotation of the rotating member 33, there are periods when the front end of the moving member 34 and the outer circumferential surface 331 of the rotating member 33 are in opposition, and periods when the front end of the moving member 34 and the notch 332 of the rotating member 33 are in opposition. During the period when the front end of the moving member 34 and the outer circumferential surface 331 of the rotating member 33 are in opposition, even if the worker tries to move the first intermediate shaft 9 forward, the contact between the front end of the moving member 34 and the outer circumferential surface 331 of the rotating member 33 prevents the first intermediate shaft 9 from moving forward. During the period when the front end of the movable member 34 and the notch 332 of the rotating member 33 are facing each other, if an attempt is made to move the first intermediate shaft 9 forward, the front end of the movable member 34 is inserted into the notch 332, so the first intermediate shaft 9 can be moved forward.

[0075] As described above, the movement of the first intermediate shaft 9 forward releases the spline coupling, interrupting the transmission of power from the first intermediate shaft 9 to the second intermediate shaft 10. Furthermore, the insertion of the front end of the movable member 34 into the notch 332 prevents the rotation of the rotating member 33, thereby preventing the rotation of the spur gear 13, the first intermediate gear 14, the second intermediate gear 15, and the toothless gear 16. The prevention of the rotation of the toothless gear 16 stops the rotation of the tip socket 4. In this way, synchronized with the power interruption by the power interruption mechanism 6, the front end of the movable member 34 is inserted into the notch 332 of the rotating member 33, and the rotation of the tip socket 4 stops with the socket opening 4M and the housing opening 2M aligned.

[0076] In this embodiment, the number of teeth of the spur gear 13 and the number of teeth of the missing gear 16 are the same. The number of teeth of the missing gear 16 represents the number of teeth if the gear opening 16M were not present. That is, the rotation ratio of the spur gear 13 and the rotation ratio of the missing gear 16 are the same. Furthermore, the initial rotational positions of the rotating member 33 and the tip socket 4 are pre-adjusted so that when the front end of the movable member 34 is inserted into the notch 332 and the rotation of the tip socket 4 stops, the housing opening 2M and the socket opening 4M of the tip socket 4 coincide. As a result, the housing opening 2M and the socket opening 4M of the tip socket 4 coincide simply by the operator pushing the power tool 100 in.

[0077] The magnet 8 is provided in the tip socket 4. The magnet 8 is positioned on the inner surface of the recess 4R of the tip socket 4. The inner surface of the recess 4R of the tip socket 4 includes a first side surface 4A, a second side surface 4B that faces the first side surface 4A with a gap between them, and a back surface 4C that connects the rear end of the first side surface 4A and the rear end of the second side surface 4B. The socket opening 4M is provided between the front end of the first side surface 4A and the front end of the second side surface 4B.

[0078] The magnet 8 is plate-shaped. The external shape of the magnet 8 is substantially rectangular. The front surface of the magnet 8 is positioned between the rear end of the first side surface 4A and the rear end of the second side surface 4B. The magnet 8 is positioned on the back surface 4C. In this embodiment, the magnet 8 is positioned in a recess 4D provided on the back surface 4C. The back surface 4C and the front surface of the magnet 8 positioned in the recess 4D are substantially on the same plane (flush).

[0079] By providing a magnet 8 inside the tip socket 4, when the bundle body 201 is inserted inside the tip socket 4, the bundle body 201 is attracted to the tip socket 4 by the magnetic force of the magnet 8. This suppresses play between the tip socket 4 and the bundle body 201. The magnet 8 can, for example, align the rotation axis AX of the tip socket 4 with the central axis of the bundle body 201. The attachment 1 can rotate the bundle body 201 while suppressing eccentricity between the tip socket 4 and the bundle body 201.

[0080] The magnet 8 is positioned on the back surface 4C. That is, the magnet 8 is positioned far from the socket opening 4M. This ensures that when the bundle body 201 is inserted into the tip socket 4 through the socket opening 4M, the magnetic force of the magnet 8 is exerted only after the bundle body 201 has been inserted all the way into the tip socket 4. For example, if the magnet 8 were positioned near the socket opening 4M, the bundle body 201 might be attracted to the magnet 8 before it is inserted all the way into the tip socket 4, making it difficult to smoothly insert the bundle body 201 all the way into the tip socket 4. In this embodiment, since the magnet 8 is positioned far from the socket opening 4M, the bundle body 201 is attracted to the tip socket 4 by the magnet 8 only after it has been inserted all the way into the tip socket 4.

[0081] The first side 4A, the second side 4B, and the back surface 4C are all parallel to the axis of rotation CX. The shape of the first side 4A is substantially rectangular. The shape of the second side 4B is substantially rectangular. The shape of the back surface 4C is substantially rectangular. The vertical dimension of the first side 4A, parallel to the axis of rotation CX, is greater than the horizontal dimension of the first side 4A, perpendicular to the axis of rotation CX. The vertical dimension of the second side 4B, parallel to the axis of rotation CX, is greater than the horizontal dimension of the second side 4B, perpendicular to the axis of rotation CX. The vertical dimension of the back surface 4C, parallel to the axis of rotation CX, is greater than the horizontal dimension of the back surface 4C, perpendicular to the axis of rotation CX. In other words, the shape of the first side 4A is a rectangle that is elongated vertically. The shape of the second side 4B is a rectangle that is elongated vertically. The shape of the back surface 4C is a rectangle that is elongated vertically. Because the inner surface of the recess 4R is elongated in the vertical direction, play between the tip socket 4 and the bundle body 201 when the bundle body 201 is held by the tip socket 4 is suppressed. The rotation axis AX of the tip socket 4 and the central axis of the bundle body 201 can be aligned. The attachment 1 can rotate the bundle body 201 while suppressing eccentricity between the tip socket 4 and the bundle body 201.

[0082] Figure 12 is a cross-sectional view showing the operation of the attachment 1 according to the embodiment. Figure 13 is a bottom view showing the operation of the input shaft 3, tip socket 4, power transmission mechanism 5, power cut-off mechanism 6, front stop mechanism 7, and magnet 8 according to the embodiment.

[0083] With the input shaft 3 and the first intermediate shaft 9 pulled backward, the operator inserts the input shaft 3 into the tool hole 102 of the power tool 100 and positions the tip socket 4 around the bundle body 201. With the input shaft 3 inserted into the tool hole 102 of the power tool 100 and the tip socket 4 positioned around the bundle body 201, the operator operates the trigger switch of the power tool 100. This causes the output shaft 101 of the power tool 100 to rotate. As the output shaft 101 rotates, the input shaft 3 and the first intermediate shaft 9 also rotate.

[0084] During power transmission, when the input shaft 3 and the first intermediate shaft 9 are pulled backward, the internal spline teeth 9G of the first intermediate shaft 9 and the external spline teeth 10G of the second intermediate shaft 10 mesh. As a result, the rotation of the first intermediate shaft 9 is transmitted to the second intermediate shaft 10. When the rotation of the first intermediate shaft 9 is transmitted to the second intermediate shaft 10, the power of the electric tool 100 input to the input shaft 3 is transmitted to the tip socket 4 via the power transmission mechanism 5. During power transmission, the moving member 34 is separated from the rotating member 33, so the rotation of the rotating member 33 is not hindered. As the tip socket 4 rotates, the bundle body 201 rotates. As the bundle body 201 rotates, the length of the steel bundle 200 is adjusted.

[0085] The bundle body 201 can rotate smoothly with minimal wobbling from the tip socket 4 due to the magnetic force of the magnet 8. The tip socket 4 can rotate stably.

[0086] After the length of the steel beam 200 is adjusted, the operator pushes the power tool 100 forward so that the rotation of the tip socket 4 stops, thereby moving the input shaft 3 and the first intermediate shaft 9 forward. When the input shaft 3 and the first intermediate shaft 9 are switched to move forward, the spline internal teeth 9G move forward relative to the spline external teeth 10G. Also, the front end of the moving member 34 approaches the rotating member 33. During the rotation of the rotating member 33, when the front end of the moving member 34 and the outer circumferential surface 331 of the rotating member 33 are facing each other, the front end of the moving member 34 strikes the outer circumferential surface 331 of the rotating member 33, preventing the moving member 34 from moving forward. By preventing the moving member 34 from moving forward, the input shaft 3 and the first intermediate shaft 9 are also prevented from moving forward.

[0087] As the operator continues to push the power tool 100 forward, the rotation of the rotating member 33 causes the front end of the moving member 34 to face the notch 332 of the rotating member 33, allowing the moving member 34 to move forward. When the moving member 34 is allowed to move forward and the input shaft 3 and the first intermediate shaft 9 move forward, the internal spline teeth 9G are positioned in front of the external spline teeth 10G, and the spline coupling between the internal spline teeth 9G and the external spline teeth 10G is released. When the power is cut off and the spline coupling between the internal spline teeth 9G and the external spline teeth 10G is released, the power of the power tool 100 is not transmitted to the tip socket 4, even if the power tool 100 continues to rotate the input shaft 3 and the first intermediate shaft 9. Also, in synchronization with the release of the spline coupling between the internal spline teeth 9G and the external spline teeth 10G, the front end of the moving member 34 is inserted into the notch 332. This stops the rotation of the rotating member 33. As the rotation of the rotating member 33 stops, the rotation of the tip socket 4 also stops. The rotation of the tip socket 4 stops when the housing opening 2M and the socket opening 4M are aligned. Since the rotation of the tip socket 4 stops when the housing opening 2M and the socket opening 4M are aligned, the worker can immediately pull the attachment 1 out of the bundle body 201.

[0088] [effect] As described above, in this embodiment, the attachment 1 is rotatable around a first rotation axis, which is a rotation axis AX, and includes an input shaft 3 into which power is input from an electric tool 100, a tip socket 4 having a recess 4R, a housing 2 having a housing opening 2M into which the bundle body 201, which is the workpiece, is inserted, and which rotatably supports the tip socket 4, a power transmission mechanism 5 that transmits the power input to the input shaft 3 to the tip socket 4, and a front stop mechanism 7 that stops the rotation of the tip socket 4 when the socket opening 4M of the recess 4R and the housing opening 2M are aligned.

[0089] In the above configuration, the bundle body 201 is inserted into the recess 4R of the tip socket 4 via the housing opening 2M and the socket opening 4M. Power is input to the input shaft 3, causing the tip socket 4 to rotate. The rotation of the tip socket 4 causes the bundle body 201 to rotate. The rotation of the bundle body 201 adjusts the length of the steel bundle 200. After the length adjustment of the steel bundle 200 is completed, the rotation of the tip socket 4 stops when the socket opening 4M and the housing opening 2M are aligned, due to the operation of the front stop mechanism 7. This allows the worker to immediately remove the attachment 1 from the bundle body 201. Since the attachment 1 can be immediately removed from the bundle body 201 after the work of adjusting the length of the steel bundle 200 is completed, the work time is kept from being prolonged.

[0090] In this embodiment, the attachment 1 includes a power cutoff mechanism 6 capable of cutting off power. The front stop mechanism 7 stops the rotation of the tip socket 4 in a state where the socket opening 4M of the recess 4R and the housing opening 2M are aligned, in synchronization with the power cutoff.

[0091] In the above configuration, after the length of the steel beam 200 has been adjusted, the power cut-off mechanism 6 and the front stop mechanism 7 are activated in sync, thereby reducing the reaction torque applied to the operator from the attachment 1 when the rotation of the tip socket 4 stops.

[0092] In this embodiment, the power transmission mechanism 5 includes a toothless gear 16 provided on the outer circumferential surface of the tip socket 4, and a spur gear 13 coupled to the toothless gear 16 and having the same number of teeth as the toothless gear 16. The front stop mechanism 7 includes a rotating member 33 fixed to the spur gear 13 and having a notch 332, and a movable member 34 that is inserted into the notch 332 in synchronization with the interruption of power.

[0093] In the above configuration, the rotation of the spur gear 13 is stopped when the movable member 34 is inserted into the notch 332. Since the number of teeth of the missing tooth gear 16 is the same as the number of teeth of the spur gear 13, the rotation of the missing tooth gear 16 is stopped when the rotation of the spur gear 13 stops, so that the socket opening 4M and the housing opening 2M align.

[0094] In this embodiment, the power transmission mechanism 5 includes a first intermediate shaft 9 connected to the input shaft 3 and rotating together with the input shaft 3, and a second intermediate shaft 10 spline-coupled to the first intermediate shaft 9 and transmitting the power input to the input shaft 3 to the spur gear 13. The power cut-off mechanism 6 releases the spline coupling.

[0095] In the above configuration, the power transmitted from the input shaft 3 to the tip socket 4 is interrupted when the spline connection is released.

[0096] In this embodiment, the attachment 1 is supported by the housing 2 and includes a bearing 19, which is a sliding bearing supporting the first intermediate shaft 9. The input shaft 3 and the first intermediate shaft 9 are movable in a forward-reverse direction parallel to the rotation axis AX. Moving the input shaft 3 and the first intermediate shaft 9 forward releases the spline coupling.

[0097] In the above configuration, when the power tool 100 is pushed forward by the operator, the input shaft 3 and the first intermediate shaft 9 move forward. This releases the spline connection.

[0098] In this embodiment, the movable member 34 moves in the front-rear direction together with the input shaft 3 and the first intermediate shaft 9. As the input shaft 3 and the first intermediate shaft 9 move forward, the movable member 34 is inserted into the notch 332.

[0099] In the above configuration, the power tool 100 is pushed forward by the operator, causing the input shaft 3 and the first intermediate shaft 9 to move forward. As a result, the moving member 34 is inserted into the notch 332, and the rotation of the toothless gear 16 stops so that the socket opening 4M and the housing opening 2M align.

[0100] In this embodiment, the power transmission mechanism 5 has a first intermediate gear 14 and a second intermediate gear 15 that mesh with a spur gear 13. The spur gear 13 is coupled to a toothless gear 16 via at least one of the first intermediate gear 14 and the second intermediate gear 15. During the rotation of the spur gear 13, at least one of the first intermediate gear 14 and the second intermediate gear 15 meshes with the toothless gear 16.

[0101] In the above configuration, during the rotation of the missing tooth gear 16, when the missing tooth gear 16 and the first intermediate gear 14 cannot mesh, the missing tooth gear 16 meshes with the second intermediate gear 15. Therefore, the rotational force of the spur gear 13 is transmitted to the missing tooth gear 16 via the second intermediate gear 15. Similarly, when the missing tooth gear 16 and the second intermediate gear 15 cannot mesh, the missing tooth gear 16 meshes with the first intermediate gear 14. Therefore, the rotational force of the spur gear 13 is transmitted to the missing tooth gear 16 via the first intermediate gear 14.

[0102] In this embodiment, the attachment 1 includes a magnet 8 positioned on the inner surface of the recess 4R.

[0103] In the above configuration, the bundle body 201 is attracted to the inner surface of the recess 4R. This prevents the tip socket 4 from rotating while the central axis of the bundle body 201 and the rotation axis CX, which is the second rotation axis of the tip socket 4, are misaligned. Therefore, the attachment 1 can rotate the bundle body 201 stably.

[0104] In this embodiment, the inner surface of the recess 4R includes a first side surface 4A and a second side surface 4B that faces the first side surface 4A with a gap between them. The socket opening 4M is provided between the front end, which is one end of the first side surface 4A, and the front end, which is one end of the second side surface 4B. The front surface, which is the surface of the magnet 8, is positioned between the other end of the first side surface 4A and the other end of the second side surface 4B.

[0105] In the above configuration, since the magnet 8 is positioned on the back surface 4C of the recess 4R, when the bundle body 201 is inserted into the recess 4R via the socket opening 4M, the bundle body 201 is prevented from being attracted to at least one of the first side surface 4A and the second side surface 4B. The bundle body 201 is attracted to the magnet 8 after being inserted all the way to the back of the recess 4R, thus preventing a decrease in workability when inserting the bundle body 201 into the tip socket 4.

[0106] The first side 4A, the second side 4B, and the back side 4C are each parallel to the rotation axis CX of the tip socket 4. The dimensions of the first side 4A, the second side 4B, and the back side 4C in the direction parallel to the second rotation axis are greater than the dimensions of the first side 4A, the second side 4B, and the back side 4C in the direction perpendicular to the second rotation axis.

[0107] In the above configuration, rotation of the tip socket 4 is suppressed when the central axis of the bundle body 201 and the rotation axis CX of the tip socket 4 are misaligned. Therefore, the attachment 1 can rotate the bundle body 201 stably.

[0108] [Other embodiments] In the above-described embodiment, the workpiece held by the tip socket 4 does not have to be the bundle body 201; for example, it may be a turnbuckle or a lock nut. [Explanation of Symbols]

[0109] 1...Attachment, 2...Housing, 2A...Lower housing, 2B...Upper housing, 2C...Rear housing, 2D...Cylindrical part, 2E...Support part, 2F...Support part, 2G...Support part, 2H...Support part, 2K...Guide hole, 2M...Housing opening, 3...Input shaft, 3A...Groove, 4...Tip socket, 4A...First side, 4B...Second side, 4C...Back surface, 4D...Recess, 4M...Socket opening, 4R...Recess, 5...Power transmission mechanism, 6...Power cutoff mechanism, 7...Front stop mechanism, 8...Magnet, 9...First Intermediate shaft, 9A...spline hole, 9B...internal space, 9C...support surface, 9D...groove, 9G...spline internal teeth, 10...second intermediate shaft, 10A...groove, 10B...flange section, 10C...support surface, 10G...spline external teeth, 11...first bevel gear, 12...second bevel gear, 13...spur gear, 14...first intermediate gear, 14A...shaft, 15...second intermediate gear, 15A...shaft, 16...missing tooth gear, 16M...gear opening, 17...ball, 18...leaf spring, 18A...opening, 19...be 20...Bearing, 21...Snap ring, 22...Snap ring, 23...Coil spring, 24...Third intermediate shaft, 25...Bearing, 26...Bearing, 27...Bearing, 28...Bearing, 29...Bearing, 30...Bearing, 31...Bearing, 31M...Bearing opening, 32...Bearing, 32M...Bearing opening, 33...Rotating member, 331...Outer circumference, 332...Notch, 332A...First side, 332B...Second side, 332C...Contact surface, 332 D...First tapered surface, 332E...Second tapered surface, 34...Moving member, 35...Connecting member, 35A...Arc section, 36...Screw, 100...Power tool, 101...Output shaft, 102...Tool hole, 200...Steel support (floor support), 201...Support body, 202...Lower threaded rod, 203...Upper threaded rod, 204...Base plate, 205...Support plate, 206...Lower lock nut, 207...Upper lock nut, 301...Foundation part, 302...Main beam, AX...Rotating shaft (first rotating shaft), BX...Rotating shaft, CX...Rotating shaft (second rotating shaft).

Claims

1. It is rotatable around the first axis of rotation, and has an input shaft to which power is input from an electric tool, A tip socket having a recess, A housing having a housing opening into which the workpiece is inserted, and which rotatably supports the tip socket, A power transmission mechanism that transmits power input to the input shaft to the tip socket, The system includes a front stop mechanism that stops the rotation of the tip socket when the socket opening of the recess and the housing opening are aligned, The power transmission mechanism comprises a toothless gear provided on the outer circumferential surface of the tip socket, a first intermediate gear and a second intermediate gear, a spur gear coupled to the toothless gear via at least one of the first intermediate gear and the second intermediate gear, a first intermediate shaft connected to the input shaft and rotating together with the input shaft, and a second intermediate shaft having a rear portion inserted into a hole provided in the front portion of the first intermediate shaft and transmitting power input to the input shaft to the spur gear. Each of the first intermediate gear and the second intermediate gear meshes with the spur gear, During the period when the missing tooth gear and the first intermediate gear cannot mesh, the missing tooth gear and the second intermediate gear mesh, and during the period when the missing tooth gear and the second intermediate gear cannot mesh, the missing tooth gear and the first intermediate gear mesh. The rotation ratio of the spur gear and the rotation ratio of the toothless gear are the same. The front stopping mechanism comprises a rotating member fixed to the spur gear and having a notch, and a movable member inserted into the notch. The input shaft and the first intermediate shaft are supported by the housing so as to be movable in a front-to-back direction parallel to the first rotation axis relative to the second intermediate shaft, with the rear portion of the second intermediate shaft inserted into a hole provided in the front portion of the first intermediate shaft. The moving member moves in the front-rear direction together with the input shaft and the first intermediate shaft. As the input shaft and the first intermediate shaft move forward, the moving member is inserted into the notch, causing the rotation of the tip socket to stop when the socket opening and the housing opening are aligned. attachment.

2. The housing is held by a bearing that supports the first intermediate shaft, The input shaft is supported by the housing via the first intermediate shaft and the bearing. The attachment according to claim 1.

3. The system includes a power interruption mechanism capable of interrupting the aforementioned power, The front stop mechanism stops the rotation of the tip socket in a state where the socket opening of the recess and the housing opening are aligned, in synchronization with the power cutoff. The attachment according to claim 2.

4. The hole provided in the front part of the first intermediate shaft is a spline hole into which the rear part of the second intermediate shaft is inserted. The second intermediate shaft is spline-coupled to the first intermediate shaft, The power cut-off mechanism releases the spline coupling. The attachment according to claim 3.

5. The spline coupling is released by the forward movement of the input shaft and the first intermediate shaft. The attachment according to claim 4.

6. The recess is provided with a magnet positioned on its inner surface. The attachment according to claim 1.

7. The inner surface of the recess includes a first surface and a second surface facing the first surface with a gap between them. The socket opening is provided between one end of the first side surface and one end of the second side surface. The surface of the magnet is positioned between the other end of the first side surface and the other end of the second side surface. The attachment according to claim 6.

8. The inner surface of the recess includes the inner surface connecting the other end of the first side surface and the other end of the second side surface. The magnet is positioned on the back surface. The attachment according to claim 7.

9. The aforementioned tip socket rotates around the second rotation axis, Each of the first side surface, the second side surface, and the back surface is parallel to the second axis of rotation, The dimensions of the first side surface, the second side surface, and the back surface in the direction parallel to the second axis of rotation are greater than the dimensions of the first side surface, the second side surface, and the back surface in the direction perpendicular to the second axis of rotation. The attachment according to claim 8.

Images