Lifting tool

Abstract

To provide an easy-to-handle hoisting tool.SOLUTION: A hoisting tool includes a chain connected to an object to be hoisted, and a hoisting tool main body that suspends the object via the chain. The hoisting tool main body includes an exterior part including a hook part that is hooked onto a hoisting machine, a wheel that is rotatably attached to the exterior part and has a fitting part formed on an outer circumferential side face to fit with the chain, a locking mechanism that can restrict the rotation of the wheel, and a brake mechanism that brakes the rotation of the wheel. The wheel is vertically movable relative to the exterior part, and the locking mechanism includes biasing means that biases the wheel upward while allowing the wheel to move vertically, and a pair of opposing meshing parts that come into contact with and separate from each other by changing the position of the wheel in the vertical direction. One meshing part is fixed to the wheel, and the other meshing part is fixed to the exterior part, and the brake mechanism includes a brake shoe that presses against the wheel, and adjustment means that adjusts the pressing force of the brake shoe against the wheel.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a lifting tool used when lifting heavy objects or the like.

Background Art

[0002] As such a lifting tool, for example, a suspension pulley including a rope connected to a load to be lifted and a main body portion that suspends the load to be lifted via the rope, as disclosed in Patent Document 1, is known.

[0003] The main body portion includes a pair of snatch plates arranged opposite to each other, and a hanging metal fitting attached between the pair of snatch plates, the hanging metal fitting being for hanging on a hoist, and a rope sheave around which a rope is wound, the rope sheave being rotatably attached between the pair of snatch plates, and a stopping means for stopping the rotation of the rope sheave.

[0004] A single sheave shaft is inserted through the rope sheave and the pair of snatch plates. This sheave shaft is configured to be able to change its arrangement in the vertical direction with respect to the snatch plate, and is placed on a spring attached to the snatch plate so as to expand and contract in the vertical direction.

[0005] Therefore, the rope sheave is arranged closer to the upper side of the snatch plate unless a load greater than the biasing force of the spring is applied, and when a load greater than the biasing force of the spring is applied, the arrangement position with respect to the snatch plate is changed from the upper side to the lower side.

[0006] The stopping means includes a wave-shaped inner corrugated tooth formed on the inner peripheral surface of the hollow (annular) rope sheave, and a sector fixed inside the snatch plate in a state of facing the inner corrugated tooth from below, and an outer corrugated tooth meshing with the inner corrugated tooth is formed on the upper surface of the sector.

[0007] When lifting a load to be lifted using the hanging pulley with the above configuration, wind the rope around the outer peripheral side of the rope sheave, connect both ends to the load to be lifted, and hang the hanging hardware on the hoist.

[0008] In such a state, the hanging pulley is lifted by the hoist. However, when the hoist starts to lift the main body, if the center of gravity position of the load to be lifted is deviated from the lifting center line (an imaginary line extending vertically through the position where the main body is lifted), as the wheel rotates, the main body moves toward the center of gravity of the load to be lifted, so the arrangement position of the main body is automatically adjusted so that the center of gravity position of the load to be lifted and the lifting center line overlap.

[0009] When the load to be lifted is lifted from the ground, a load greater than the biasing force of the spring is applied to the rope sheave. Therefore, the arrangement position of the rope sheave with respect to the snatch plate is changed from the upper side to the lower side. Along with this, the inner corrugated teeth and the outer corrugated teeth mesh, and the rope sheave is fixed to the snatch plate so as not to rotate. Thus, it is said that the load to be lifted can be lifted while the arrangement position of the main body with respect to the load to be lifted does not change.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0011] By the way, in the hanging pulley with the above configuration, until the inner corrugated teeth and the outer corrugated teeth mesh and the rope sheave is fixed to the snatch plate so as not to rotate, the rope sheave can rotate freely. Therefore, the rope sheave may rotate at an unintended timing, which is a difficult point to handle.

[0012] Therefore, in view of such a situation, an object of the present invention is to provide a lifting tool that is easy to handle.

Means for Solving the Problem

[0013] The hoist of the present invention is a long chain, including a chain connected to an object to be lifted, and a hoist main body for lifting the object to be lifted via the chain. The hoist main body includes an exterior part including a part to be hung on a hoisting machine, a wheel rotatably attached to the exterior part, a fitting part formed on the outer peripheral surface thereof for fitting with the chain, a lock mechanism that can be switched between a state of restricting the rotation of the wheel and a state of releasing the restriction on the rotation of the wheel, and a brake mechanism for braking the rotation of the wheel. The wheel is vertically movable relative to the exterior part. The lock mechanism includes biasing means for biasing upward in a state allowing the vertical movement of the wheel, and a pair of meshing parts arranged to face each other in the vertical direction, the pair of meshing parts coming into contact with and separating from each other as the vertical position of the wheel relative to the exterior part changes. One of the pair of meshing parts is fixed to the wheel. The other of the pair of meshing parts is fixed to the exterior part. The brake mechanism includes a brake shoe pressed against the wheel and adjusting means for adjusting the pressing force of the brake shoe against the wheel.

[0014] To lift an object to be lifted using the hoist configured as above, the chain with both ends connected to the object to be lifted is hung on the wheel, and the part to be hung of the exterior part is hung on the hoisting machine.

[0015] While a load greater than the biasing force of the biasing means is not applied to the wheel, the wheel can rotate if an external force exceeding the braking force of the brake mechanism is applied, so that the arrangement position of the hoist main body can be changed along the chain.

[0016] When the exterior part is lifted by a hoisting machine and a load greater than the biasing force of the biasing means is applied to the wheel, while the wheel attempts to stay in place, the exterior part continues to be lifted. As a result, the position of the wheel relative to the exterior part changes from the upper side to the lower side. Along with this, the engaging part fixed to the wheel and the engaging part fixed to the exterior part mesh with each other, restricting the rotation of the wheel.

[0017] Furthermore, in the lifting tool with the above configuration, if the pressing force of the brake shoe against the wheel is increased by the adjusting means, the rotation of the wheel can be braked. Therefore, it is possible to prevent the wheel from rotating at an unintended timing, thereby improving the ease of handling.

[0018] In the lifting tool of the present invention, On the outer peripheral side surface of the wheel, a fitting groove into which the chain fits and a braking contact portion against which the brake shoe abuts are formed. The braking contact portion may be formed at the bottom of the fitting groove.

[0019] According to the lifting tool with the above configuration, since the fitting groove into which the chain fits and the braking contact portion against which the brake shoe abuts are integrally formed, it is possible to exhibit the function of making the wheel difficult to rotate with a simple structure.

[0020] In the lifting tool of the present invention, The adjusting means has a lever exposed outside the exterior body. The lever may be configured such that its posture changes according to the pressing force of the brake shoe against the wheel.

[0021] According to the lifting tool with the above configuration, by looking at the direction of the lever, it becomes possible to confirm the strength of the braking force with which the braking mechanism acts on the rotational movement of the wheel, thereby improving the ease of handling.

[0022] In the lifting tool of the present invention, The suspension tool body has switching restriction means for disabling switching to a state of restricting the rotation of the wheel of the locking mechanism. The switching restriction means may be provided on the exterior portion and configured to directly or indirectly hold the wheel from below in a state where the exterior portion is tilted to one end side or the other end side of the chain.

[0023] When the exterior portion of the suspension tool configured as described above is pulled upward obliquely by a hoisting machine (when the exterior portion is in a state of being obliquely pulled), the switching restriction means directly or indirectly holds the wheel from below, so that the wheel cannot be repositioned downward relative to the exterior portion.

[0024] Accordingly, switching to a state of restricting the rotation of the wheel by the locking mechanism is also impossible. By keeping the wheel rotatable, it is possible to prevent the object to be hoisted from being hoisted while receiving a lateral force, and thus the object to be hoisted can be safely hoisted.

Advantages of the Invention

[0025] As described above, the suspension tool of the present invention can achieve an excellent effect of being easy to handle.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, a lifting tool according to an embodiment of the present invention will be described with reference to the accompanying drawings. The vertical direction and the horizontal direction are based on the states shown in FIGS. 1 to 4.

[0028] As shown in FIG. 1, the lifting tool 1 according to this embodiment includes a long chain 2 whose both ends can be connected to a lifting object (for example, a heavy object), and a tool body portion 3 that suspends the lifting object via the chain 2.

[0029] At both ends of the chain 2 in the longitudinal direction, coupling means 20 such as couplings, hooks, shackles, etc. are provided, and both ends of the chain 2 are connected to the object to be suspended by this coupling means 20.

[0030] The chain 2 of the present embodiment is configured by connecting a plurality of rings 200. The ring 200 is in an elliptical ring shape and has a pair of straight portions 200a parallel to each other and arc portions 200b connecting the ends of one adjacent straight portion 200a and the ends of the other straight portion 200a.

[0031] As shown in FIG. 2, the hoist body portion 3 includes an exterior portion 30 including a portion 300 to be hung on a hoisting machine (for example, a crane, etc.), a wheel 31 on which the chain 2 is hung on the outer peripheral side surface and is rotatably attached to the exterior portion 30, a lock mechanism 32 that can be switched between a state where the rotation of the wheel 31 is restricted (locked state) and a state where the restriction on the rotation of the wheel 31 is released (unlocked state), a brake mechanism 33 that brakes the rotation of the wheel 31, and a switching restriction means 34 that makes it impossible to switch from the locked state of the lock mechanism 32 to the unlocked state.

[0032] The exterior portion 30 of the present embodiment has a pair of plates 301 arranged opposite to each other with a space therebetween and a roller shaft 302 arranged between the pair of plates 301.

[0033] One end of the roller shaft 302 in the axial direction is attached to one plate 301, and the other end in the axial direction is attached to the other plate 301. And in the hoist 1 of the present embodiment, this roller shaft 302 constitutes the portion 300 to be hung.

[0034] The wheel 31 is disposed between a pair of plates 301. A rotary shaft P1 is inserted through a through-hole at the center of the wheel 31 and through each of the pair of plates 301 (specifically, shaft insertion portions 320, which will be described later, formed in each of the pair of plates 301). Thereby, the wheel 31 is rotatably attached to the exterior portion 30.

[0035] As shown in FIG. 4, a fitting groove 310 into which the chain 2 is fitted and a braking contact portion 311 against which a brake shoe 35, which will be described later, abuts are formed on the outer peripheral side surface of the wheel 31 of the present embodiment.

[0036] As shown in FIG. 5(a), the fitting groove 310 is formed so as to open on the outer peripheral side surface of the wheel 31 and is formed to be continuous over the entire circumference of the outer peripheral side surface of the wheel 31.

[0037] The fitting groove 310 of the present embodiment is a deep groove portion 310a formed on the outer peripheral side surface of the wheel 31, and includes a deep groove portion 310a formed to be continuous over the entire circumference of the outer peripheral side surface of the wheel 31, and a plurality of shallow groove portions 310b formed on the outer peripheral side surface of the wheel 31, the plurality of shallow groove portions 310b being formed to be arranged along the circumferential direction of the wheel 31.

[0038] The depth of each of the plurality of shallow groove portions 310b is shallower than that of the deep groove portion 310a (see FIG. 5(b)).

[0039] Each of the plurality of shallow groove portions 310b has a pair of shallow groove forming portions 310c formed so as to be arranged via the deep groove portion 310a in the thickness direction of the wheel 31.

[0040] One of the pair of shallow groove forming portions 310c is continuous with one side in the thickness direction of the wheel 31 with respect to the deep groove portion 310a (one side in the groove width direction of the deep groove portion 310a), and the other shallow groove forming portion 310c of the pair of shallow groove forming portions 310c is continuous with the other side in the thickness direction of the wheel 31 with respect to the deep groove portion 310a (the other side in the groove width direction of the deep groove portion 310a).

[0041] Each of the plurality of shallow groove portions 310b is formed so as to be arranged at intervals in the circumferential direction of the wheel 31.

[0042] As shown in FIG. 5(b), the ring 200 enters the shallow groove portion 310b in a horizontal orientation (horizontal with respect to the outer peripheral side surface of the wheel 31), and the ring 200 enters the deep groove portion 310a in a vertical orientation (vertical with respect to the outer peripheral side surface of the wheel 31). Therefore, in a state where the chain 2 is hung on the wheel 31, the shallow groove portion 310b and the horizontally oriented ring 200 are engaged with each other in the circumferential direction of the wheel 31.

[0043] The brake contact portion 311 is constituted by the deep groove portion 310a. That is, the deep groove portion 310a serves both as a portion into which the vertically oriented ring 200 enters and a portion into which the brake mechanism 33 (brake shoe 330 described later) enters.

[0044] The bottom surface of the brake contact portion 311 is formed so that the cross section in the radial direction is linear, and the brake shoe 330 described later abuts against this bottom surface. Although the chain 2 is hung on the upper side of the wheel 31, the lower side of the wheel 31 remains open, so that the brake shoe 330 can be brought into contact with the bottom surface of the brake contact portion 311 from the lower side of the wheel 31.

[0045] As shown in FIG. 3, the locking mechanism 32 includes a shaft insertion portion 320 formed in the exterior portion 30, through which a rotating shaft P1 inserted through the wheel 31 is inserted in a vertically movable state, a biasing means 321 that biases the wheel 31 upward while allowing vertical movement of the wheel 31, and a pair of meshing portions 322, 323 that are arranged to face each other in the vertical direction and engage and disengage with each other as the vertical position of the wheel 31 relative to the exterior portion 30 changes.

[0046] The shaft insertion portion 320 is constituted by a long hole (a long hole extending along the vertical direction) formed in the exterior portion 30. Therefore, when the rotating shaft P1 is inserted into the shaft insertion portion 320, while movement in the vertical direction is allowed, movement of the rotating shaft P1 in the left - right direction is restricted. And the wheel 31 through which the rotating shaft P1 is inserted is also, when the rotating shaft P1 is inserted into the shaft insertion portion 320, allowed to move in the vertical direction while its movement in the left - right direction is restricted.

[0047] The biasing means 321 supports the rotating shaft P1 inserted into the shaft insertion portion 320 from below. Also, since the biasing means 321 biases the rotating shaft P1 upward while allowing vertical movement of the rotating shaft P1 in the shaft insertion portion 320, the wheel 31 through which the rotating shaft P1 is inserted is also in a state of receiving an upward biasing force while vertical movement is allowed.

[0048] Therefore, when a load greater than the biasing force of the biasing means 321 is applied to the wheel 31 when the exterior portion 30 is lifted by the hoisting machine, the arrangement position of the wheel 31 relative to the exterior portion 30 changes downward, and when the load changes from a state where it exceeds the biasing force of the biasing means 321 to a state where it is less than the biasing force, the arrangement position of the wheel 31 relative to the exterior portion 30 changes (returns) upward.

[0049] Note that the biasing force of the biasing means 321 is set to such an extent that, as the hoisting tool main body 3 is hoisted and the object to be suspended moves away from the ground surface, the pair of meshing portions 322, 323 are held so as not to mesh with each other.

[0050] Further, the biasing means 321 may be configured using an elastically deformable elastic body such as a torsion spring. In this case, the biasing means 321 includes a mounting portion 321a that is spiral and has a fixing shaft inserted therein, and a pair of extending portions 321b that extend from the mounting portion 321a, and one of the extending portions 321b pushes up the rotating shaft P1.

[0051] One of the pair of meshing portions 322, 323, the wheel-side meshing portion 322, is attached to the wheel 31 by bolting, and the other of the pair of meshing portions 323, the exterior-side meshing portion 323, is fixed to the exterior portion 30 and is immovable vertically with respect to the exterior portion 30 in the attached state.

[0052] Tooth portions 3220 and 3230 that mesh with each other are formed on the wheel-side meshing portion 322 and the exterior-side meshing portion 323.

[0053] The wheel-side meshing portion 322 is formed in a disc shape, and the tooth portion 3220 is formed on the entire outer circumference of the outer surface of the wheel-side meshing portion 322. Also, the wheel-side meshing portion 322 may be fixed to the front or back of the wheel 31.

[0054] Furthermore, since the wheel-side meshing portion 322 is concentric with the wheel 31, the distance between the tooth portion 3220 of the wheel-side meshing portion 322 and the tooth portion 3230 of the exterior-side tooth portion 323 is kept constant even when the wheel 31 rotates in a state where the arrangement position of the wheel 31 with respect to the exterior portion 30 has not changed downward due to the biasing force of the biasing means 321.

[0055] The exterior-side meshing portion 323 is disposed at a position below and aligned with the wheel-side meshing portion 322 and is fixed to the exterior portion 30 (the inner surface of the plate 301 in this embodiment) with the tooth portion 3230 facing the tooth portion 3220 of the wheel-side meshing portion 322.

[0056] Here, the arrangement relationship between the wheel-side meshing portion 322 and the exterior-side meshing portion 323 will be described. As shown in Fig. 6(a), the exterior-side meshing portion 323 is arranged inside the wheel-side meshing portion 322. Also, in a state where a load greater than the biasing force of the biasing means 321 is not applied to the wheel 31, since the arrangement position of the wheel 31 with respect to the exterior portion 30 is on the upper side, the exterior-side meshing portion 323 is arranged at a position separated downward from the wheel-side meshing portion 322 in a state of facing the wheel-side meshing portion 322.

[0057] Then, when a load greater than the biasing force of the biasing means 321 is applied to the wheel 31 during the lifting of the sling body portion 3, while the wheel-side meshing portion 322 stays in place together with the wheel 31, the exterior-side meshing portion 323 is lifted upward together with the exterior portion 30. Therefore, as shown in Fig. 6(b), the arrangement position of the wheel 31 with respect to the exterior portion 30 changes from the upper side to the lower side, the exterior-side meshing portion 323 approaches the wheel-side meshing portion 322, and the tooth portion 3230 of the exterior-side meshing portion 323 meshes with the tooth portion 3220 of the wheel-side meshing portion 322.

[0058] Note that the tooth portion 3220 and the tooth portion 3230 can be formed of rounded wave-shaped teeth, triangular teeth, etc. However, if the tooth portion 3220 and the tooth portion 3230 are formed of triangular teeth as in this embodiment, it becomes easier to ensure the contact area between the tooth portion 3220 and the tooth portion 3230 in the circumferential direction of the wheel 31. Therefore, it becomes easier to enhance the effect of restricting the rotation of the wheel 31 due to the meshing of the tooth portion 3230 and the tooth portion 3230, and the rotation of the wheel 31 can be minimized. Along with this, it becomes less likely for a deviation to occur in the position of the sling body portion 3 with respect to the object to be suspended during lifting (for example, the position of the lifting center line of the sling body portion 3 with respect to the center of gravity position of the object to be suspended).

[0059] In this way, the sling body portion 3 of this embodiment is configured to switch between a state where the rotation of the wheel 31 is restricted according to the arrangement position of the wheel 31 with respect to the exterior portion 30 and a state where the restriction on the rotation of the wheel 31 is released.

[0060] As shown in FIG. 4, the brake mechanism 33 includes a brake shoe 330 that is in sliding contact with the wheel 31, and an adjustment means 331 that adjusts the pressing force of the brake shoe 330 against the wheel 31.

[0061] The brake shoe 330 is constantly in contact with the bottom surface of the braking contact portion 311. When the wheel 31 attempts to rotate or rotates, the brake shoe 330 is configured to generate a braking force against the rotation of the wheel 31. The brake shoe 330 is made of a material that can cause a frictional force with the bottom surface of the braking contact portion 311. For example, steel, resin material, sintered material, etc. can be used.

[0062] The adjustment means 331 includes a push operation portion 3310 that pushes the brake shoe 330 inward in the radial direction of the wheel 31, and an adjustment operation portion 3311 that adjusts the pressing force of the push operation portion 3310 against the brake shoe 330.

[0063] The push operation portion 3310 is configured to move in a direction of approaching and separating from the brake shoe 330 in the radial direction of the wheel 31. The adjustment operation portion 3311 is a portion that is operated when moving the push operation portion 3310 in a direction approaching the wheel 31 or separating from the wheel 31.

[0064] The push operation portion 3310 includes a push operation shaft 3310a whose one end abuts against the brake shoe 330, a shaft holding portion 3310b that holds the operation shaft 3310a in a slidable state in a direction of approaching and separating from the wheel 31, and a shaft biasing portion 3310c that biases the operation shaft 3310a in a direction away from the wheel 31.

[0065] The adjustment operation portion 3311 is constituted by an elongated lever. Also, an intermediate portion between one end portion and the other end portion in the longitudinal direction of the adjustment operation portion 3311 is rotatably attached to the exterior portion 30.

[0066] One end of the adjustment operation unit 3311 in the longitudinal direction is configured as an operation unit 3311a that is pulled by the user, and the other end of the adjustment operation unit 3311 in the longitudinal direction is configured as a shaft pressing unit 3311b that presses the pressing operation shaft 3310a toward the wheel 31 side.

[0067] In the adjustment means 331 of the present embodiment, when the operation unit 3311a is pulled downward, the entire adjustment operation unit 3311 rotates, and the shaft pressing unit 3311b moves upward. When the shaft pressing unit 3311b moves upward, it presses the pressing operation shaft 3310a toward the wheel 31 side (brake shoe 330 side), so that the pressing operation shaft 3310a presses the brake shoe 330, thereby suppressing the rotation of the wheel 31.

[0068] When the operation state of the operation unit 3311a is released, the pressing operation shaft 3310a is pushed by the shaft biasing unit 3310c and moves away from the wheel 31. When the shaft pressing unit 3311b is pushed back (pushed down) by the pressing operation shaft 3310a, the adjustment means 331 rotates and returns to the original state.

[0069] Since the adjustment operation unit 3311 of the present embodiment is configured by a lever as described above, the position of the pressing operation unit 3310 (that is, the pressing force on the brake shoe 330) can be adjusted according to the turning degree (pulling degree) of the adjustment operation unit 3311.

[0070] Further, the shaft pressing unit 3311b may be directly held by the user's hand for operation, or a rod or string may be attached for pulling operation.

[0071] As shown in FIG. 7(a), the switching restriction means 34 includes a movement restriction unit 340 that restricts the downward movement of the wheel 31 with respect to the exterior unit 30, and a connecting shaft 341 that rotatably connects the movement restriction unit 340 to the exterior unit 30.

[0072] The movement restricting part 340 is configured to enable the change of the arrangement position of the wheel 31 downward with respect to the exterior part 30 when the upper end part and the lower end part of the exterior part 30 are aligned vertically in the upright state, and to disable the change of the arrangement position of the wheel 31 downward with respect to the exterior part 30 when the upper end part and the lower end part of the exterior part 30 are displaced in the direction in which one end and the other end of the chain 2 are aligned in the inclined state.

[0073] As shown in FIG. 7(b), the movement restricting part 340 of the present embodiment engages (holds) from the lower side with respect to the rotation axis P1 when the exterior part 30 switches from the upright state to the inclined state, and as shown in FIG. 7(a), is configured to move away from the rotation axis P1 when the exterior part 30 switches from the inclined state to the upright state.

[0074] The movement restricting part 340 of the present embodiment includes a rotation connecting part 3400 rotatably connected to the exterior part 30 at a position separated upward from the rotation axis P1, and a pair of engaging claw parts 3401 extending from the rotation connecting part 3400, the pair of engaging claw parts 3401 being arranged side by side with a space therebetween.

[0075] A connecting shaft 341 is inserted through the rotation connecting part 3400 and the plate 301, and thus the rotation connecting part 3400 is configured to be rotatable about the connecting shaft 341. Therefore, the rotation connecting part 3400 swings like a pendulum with respect to the exterior part 30.

[0076] The rotation connecting part 3400 is arranged at a place where the rotation axis P1 is interposed between the pair of engaging claw parts 3401. The rotation connecting part 3400 of the present embodiment is arranged overlapping the outer surface of the plate 301. Also, a connecting shaft 341 is inserted through the rotation connecting part 3400 and the plate 301, and thus the rotation connecting part 3400 is configured to be rotatable with respect to the plate 301 (exterior part 30).

[0077] At the tip of the engaging claw part 3401, a return part 3401a protruding toward the adjacent engaging claw part 3401 side is formed.

[0078] Here, as shown in FIG. 8, the rotation axis P1 of the present embodiment includes a shaft main body portion P10 inserted into the central portion of the wheel 31, an axially guided shaft portion P11 extending outward from the shaft main body portion P10 along the axial direction of the shaft main body portion P10 and inserted into the shaft insertion portion 320 of the plate 301, and an engaged portion P12 extending outward from the tip of the axially guided shaft portion P11 along the axial direction and engaged with the movement restricting portion 340 from below.

[0079] The shaft main body portion P10 is cylindrical, but both end faces of the axially guided shaft portion P11 (both end faces in the lateral direction orthogonal to the vertical direction and the axial direction) are flat surfaces adapted to the shape of the shaft insertion portion 320, and the bottom surface of the engaged portion P12 is a flat surface with which the return portion 3401a of the engaging claw portion 3401 can be engaged from below. When the rotation axis P1 is viewed from the axial direction, the engaged portion P12 is formed in a semicircular shape, but may have a shape different from the semicircular shape as long as the return portion 3401a of the engaging claw portion 3401 can be engaged.

[0080] Also, the axially guided shaft portion P11 and the engaged portion P12 may be formed only at one end or the other end of the shaft main body portion P10, or may be formed at both one end and the other end of the shaft main body portion P10.

[0081] When the exterior portion 30 is in the upright state, the rotation connection portion 3400 is disposed above the rotation axis P1, and the pair of engaging claw portions 3401 are disposed on both sides of the rotation axis P1 (positions separated on the left and right sides). The return portions 3401a of each engaging claw portion 3401 are also disposed on both sides of the rotation axis P1. In this case, even when the arrangement position of the wheel 31 with respect to the exterior portion 30 changes from the upper side to the lower side, the rotation axis P1 remains non-contact, so the wheel 31 is in a state where the arrangement position can be changed. That is, the rotation of the wheel 31 can be restricted by the locking mechanism 32.

[0082] When the exterior part 30 changes from the upright state to the inclined state, the rotation axis P1 moves horizontally together with the exterior part 30. At this time, the connecting shaft 341 and the movement restricting part 340 also move horizontally. However, since the pair of engaging claw parts 3401 maintain the hanging posture, the movement restricting part 340 rotates relative to the rotation axis P1, and the engaging claw part 3401 gets into the state of rotating under the engaged part P12.

[0083] In this case, even if the arrangement position of the wheel 31 relative to the exterior part 30 tries to change from the upper side to the lower side, the wheel 31 is held by the switching restricting means 34 to the exterior part 30. Therefore, the arrangement position of the wheel 31 relative to the exterior part 30 cannot be changed from the upper side to the lower side. As a result, the rotation of the wheel 31 cannot be restricted by the locking mechanism 32.

[0084] The configuration of the hoist 1 according to this embodiment is as described above. Next, the usage method of the hoist 1 will be described.

[0085] When lifting the object to be lifted O using the hoist 1, the chain 2 is hung on the outer peripheral side surface of the wheel 31, and both ends are connected to the object to be lifted O.

[0086] Since the wheel 31 receives the braking force from the braking mechanism 33, as shown in FIG. 1, even if the length from the position where the chain 2 is hooked on the wheel 31 to one end (hereinafter referred to as the length on the one end side) and the length from the position where the chain 2 is hooked on the wheel 31 to the other end (hereinafter referred to as the length on the other end side) are unequal, the wheel 31 does not rotate, so this state can be maintained. Therefore, according to the position of the center of gravity of the object to be lifted O, the length on the one end side and the length on the other end side of the chain 2 can be roughly adjusted.

[0087] Then, the hooking part 300 is hung on the hoisting machine, and the arrangement position of the hoist main body part 3 is adjusted.

[0088] Before lifting the suspension tool body 3, no load greater than the biasing force of the biasing means 321 is applied to the wheel 31. Therefore, the wheel 31 is in a state of being pulled upward with respect to the exterior part 30 by the biasing force of the biasing means 321 (see Fig. 6(a)). At this time, since the tooth part 3230 of the exterior side engaging part 323 and the tooth part 3220 of the wheel side engaging part 322 are separated from each other, the wheel 31 is under the braking force of the braking mechanism 33 but is in a rotatable state.

[0089] When adjusting the arrangement position of the suspension tool body 3, the suspension tool body 3 is moved to one end side or the other end side of the chain 2 while rotating the wheel 31. For example, as shown in Figs. 8 and 9, the arrangement position of the suspension tool body 3 may be set in accordance with the center of gravity G of the object to be lifted O, but it may also be set at a position deviated from the center of gravity G of the object to be lifted. At this time, if the braking force applied by the braking mechanism 33 to the wheel 31 is weakened by operating the adjustment operation part 3311 by lever, the suspension tool body 3 can be easily moved.

[0090] In addition, since the braking mechanism 33 of the present embodiment can adjust the pressing force of the brake shoe 330 on the wheel 31 by the adjusting means 331, as long as the braking force against the rotation of the wheel 31 is generated within the range where the wheel 31 is rotatable, the wheel 31 can be prevented from rotating too much. In this way, by preventing unnecessary rotation of the wheel 31, the position of the suspension tool body 3 can be easily adjusted.

[0091] Then, the hoisting machine hoists the lifting tool main body 3. When starting to hoist the lifting tool main body 3 with the hoisting machine, if the position of the center of gravity G of the object O to be hoisted is deviated from the hoisting center line CL (a virtual line extending in the vertical direction passing through the position where the lifting tool main body 3 is hoisted), when the lifting tool main body 3 is pulled toward one end side or the other end side of the chain 2 with a force greater than the braking force of the braking mechanism 33, the wheel 31 rotates, and thus the arrangement position of the lifting tool main body 3 can be moved to one end side or the other end side of the chain 2. Therefore, when the lifting tool main body 3 is hoisted, the arrangement position of the lifting tool main body 3 is automatically adjusted so that the position of the center of gravity G of the object O to be hoisted coincides with the hoisting center line CL.

[0092] Furthermore, the arrangement position of the wheel 31 with respect to the exterior part 30 is changed from the upper side to the lower side, and when the tooth part 3220 of the wheel-side meshing part 322 meshes with the tooth part 3230 of the exterior-side meshing part 323, the rotation of the wheel 31 is completely restricted.

[0093] As described above, according to the lifting tool 1 according to the present embodiment, as described above, if the pressing force of the brake shoe 330 against the wheel 31 is increased by the adjusting means 331, the rotation of the wheel 31 can be braked. Therefore, it is possible to suppress the wheel 31 from rotating at an unintended timing, and thereby the handling ease can be improved.

[0094] Furthermore, in the lifting tool 1 of the present embodiment, since the tooth part 3220 of the wheel-side meshing part 322 is formed on the outer peripheral edge part of the wheel-side meshing part 322 formed with an outer diameter larger than that of the wheel 31, the load applied to the tooth part 3220 is reduced. Also, as the load applied to the tooth part 3220 is reduced, the tooth part 3220 can be made smaller and the number of tooth parts 3220 can be increased.

[0095] Also, in the lifting tool 1 of the present embodiment, since the fitting groove 310 into which the chain 2 is fitted and the brake contact part 311 against which the brake shoe 330 abuts are integrally formed, a simple structure can exhibit the function of making the wheel 31 difficult to rotate.

[0096] Furthermore, since the braking mechanism 33 is configured such that the adjusting means 331 for adjusting the braking force against the rotation of the wheel 31 is constituted by a lever, an operator can confirm the strength of the braking force with which the braking mechanism 33 acts on the rotational movement of the wheel 31 by looking at the direction of the lever, thereby improving the ease of handling.

[0097] Then, when the exterior part 30 is lifted obliquely upward by a hoisting machine (when the exterior part 30 is in a state of being obliquely pulled), the hoisting tool 1 of the present embodiment becomes a state in which the rotation of the wheel 31 cannot be restricted by the locking mechanism 32 by the switching restriction means 34. Therefore, by keeping the wheel 31 rotatable, it is possible to suppress the hoisting object O from being hoisted while receiving a lateral force, and thereby it becomes possible to safely hoist the hoisting object O.

[0098] Note that the hoisting tool according to the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0099] Although not particularly mentioned in the above embodiment, the wheel-side engaging portion 322 and the exterior-side engaging portion 323 may be arranged only on the front side or the rear side of the wheel 31, or may be arranged on both the front side and the rear side of the wheel 31.

[0100] In the above embodiment, the biasing means 321 is configured to push up the rotation shaft P1 from below, but is not limited to this configuration. For example, the biasing means 321 may be configured to pull up the rotation shaft P1 from above.

[0101] Although not particularly mentioned in the above embodiment, if the tooth width of the tooth portion 3220 of the wheel-side engaging portion 322 and the tooth portion 3230 of the exterior-side engaging portion 323 is increased, the strength will be enhanced. Also, it is possible to install the wheel-side engaging portion 322 and the exterior-side engaging portion 323 on one side and the other side of the wheel 31 so that the wheel 31 is supported on both sides.

[0102] In the above embodiment, the biasing means 321 was constituted by a torsion spring, but the present invention is not limited to this configuration. For example, the biasing means 321 may be constituted by a leaf spring, a bamboo spring, or a tension coil spring.

[0103] Further, as shown in FIG. 11, the biasing means 321 may be constituted by a compression coil spring. In this case, the locking mechanism 32 may be configured to include a pressing portion 324 that pushes up the rotation shaft P1 (specifically, the engaged portion P12 of the rotation shaft P1) by receiving the biasing force of the biasing means 321, and an adjustment mechanism 325 that adjusts the compression force of the biasing means 321.

[0104] As shown in FIG. 12, the pressing portion 324 includes a contact head 3240 that contacts the lower surface of the engaged portion P12 of the rotation shaft P1, a first extension shaft 3241 that extends downward from the contact head, and a second extension shaft 3242 that extends downward from the tip of the first extension shaft 3241.

[0105] The upper surface of the contact head 3240 contacts the lower surface of the engaged portion P12 of the rotation shaft P1 as described above, and the lower surface of the contact head 3240 contacts the biasing means 321.

[0106] The first extension shaft 3241 has a smaller diameter than the contact head 3240, and the second extension shaft 3242 has a smaller diameter than the first extension shaft 3241. Further, the first extension shaft 3241 and the second extension shaft 3242 are inserted inside the biasing means 321.

[0107] The adjustment mechanism 325 includes a base portion 3250 fixed to the exterior portion, a movable portion 3251 attached to the base portion 3250 so as to be vertically movable, and a lower receiving portion 3252 that receives the lower end of the biasing means 321 and is configured to move vertically together with the movable portion 3251.

[0108] The movable part 3251 shown in FIG. 12 is formed in a bolt shape and is screwed into the base part 3250. Specifically described, the movable part 3251 has a male thread formed on its outer peripheral surface and a movable shaft part 3251a that can be screwed into a threaded hole formed in the base part 3250, and a movable head part 3251b connected to one end (lower end) in the axial direction of the movable shaft part 3251a.

[0109] The movable part 3251 shown in FIG. 12 is formed in a bolt shape and is screwed into the base part 3250. Specifically described, the movable part 3251 has a male thread formed on its outer peripheral surface and a movable shaft part 3251a that can be screwed into a threaded hole formed in the base part 3250, and a movable head part 3251b connected to one end (lower end) in the axial direction of the movable shaft part 3251a.

[0110] Also, the movable shaft part 3251a has an insertion recess 3251c that opens at the other end (upper end) in the axial direction, and the second extension shaft 2342 can slide in the vertical direction. The insertion recess 3251c is formed.

[0111] The lower receiving part 3252 is annular, placed at the tip of the movable shaft part 3251a, and the second extension shaft 3242 is inserted through the central part.

[0112] The locking mechanism 32 with such a configuration can change the compression amount of the biasing means 321 by adjusting the vertical position of the movable shaft part 3251a, and thereby can adjust the force for pushing up the rotating shaft P1.

[0113] In the above embodiment, the wheel-side meshing part 322 was in the shape of a spur gear, but it may be in a shape other than the spur gear shape.

[0114] In the above-described embodiment, the wheel-side engaging portion 322 is formed in a disc shape, and the tooth portion 3220 is formed over the entire outer peripheral edge. However, the present invention is not limited to this configuration. For example, the wheel-side engaging portion 322 may be formed in an annular shape, and the tooth portion 3220 may be formed over the entire inner peripheral edge. However, when the wheel-side engaging portion 322 is formed in a disc shape with the tooth portion 3220 formed on the outer peripheral edge, it is easier to increase the outer diameter of the wheel-side engaging portion 322. Therefore, it becomes easier to reduce the size of the tooth portion 3220, and it also becomes easier to increase the number of tooth portions 3220. As a result, the load (burden) applied to the tooth portion 3220 of the wheel-side engaging portion 322 can be reduced.

Explanation of Reference Numerals

[0115] 1... Hoisting tool, 2... Chain, 3... Hoisting tool main body portion, 20... Connecting means, 30... Exterior portion, 31... Wheel, 32... Lock mechanism, 33... Brake mechanism, 34... Switching restriction means, 300... Hanging portion, 301... Plate, 302... Roller shaft, 310... Fitting groove, 311... Brake contact portion, 320... Shaft insertion portion, 321... Biasing means, 322... Engaging portion, 322... Wheel-side engaging portion, 323... Exterior-side engaging portion, 330... Brake shoe, 331... Adjusting means, 340... Movement restriction portion, 341... Connecting shaft, 3220... Tooth portion, 3230... Tooth portion, 3310... Push operation portion, 3311... Adjustment operation portion, 3400... Rotational connection portion, 3401... Engaging claw portion, 3401a... Return portion, P1... Rotation shaft, P10... Shaft main body portion, P11... Guided shaft portion, P12... Engaged portion

Claims

1. A long chain, comprising a chain connected to an object to be lifted, and a hoist body for suspending the object to be lifted via the chain. The hoist body includes an exterior portion including a portion to be hung on a hoisting machine, a wheel rotatably attached to the exterior portion, a fitting portion formed on an outer peripheral surface thereof for fitting with the chain, a locking mechanism capable of switching between a state of restricting rotation of the wheel and a state of releasing the restriction on rotation of the wheel, and a braking mechanism for braking rotation of the wheel. The wheel is vertically movable relative to the exterior portion. The locking mechanism includes biasing means for biasing upward in a state allowing vertical movement of the wheel, and a pair of meshing portions arranged to face each other in the vertical direction and coming into contact with and separating from each other as the vertical position of the wheel relative to the exterior portion changes. One of the pair of meshing portions is fixed to the wheel. The other of the pair of meshing portions is fixed to the exterior portion. The braking mechanism includes a brake shoe pressed against the wheel and adjusting means for adjusting the pressing force of the brake shoe against the wheel. An engaging groove into which the chain fits and a braking contact portion against which the brake shoe abuts are formed on an outer peripheral surface of the wheel. The braking contact portion is formed at the bottom of the engaging groove. Hoisting tool.

2. The adjusting means has a lever exposed outside the exterior portion. The lever is configured such that its posture changes according to the pressing force of the brake shoe against the wheel. The hoisting tool according to Claim 1.

3. The hoist body has switching restriction means for making it impossible to switch to a state of restricting rotation of the wheel of the locking mechanism. The switching restriction means is provided on the exterior part, and is configured to directly or indirectly hold the wheel from below in a state where the exterior part is inclined to one end side or the other end side of the chain. The suspension tool according to claim 1.

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