Anti-disengagement device for hacker and hacker

Abstract

To provide an anti-disengagement device for preventing a sling passed through a sling part of a hacker from accidentally coming off.SOLUTION: An anti-disengagement device 20 for a hacker 10 comprises an outer cylindrical body 21, an inner cylindrical body 22, a compression spring 23, and a cable tie 24. The outer cylindrical body includes an outer cylindrical protrusion 21f that can be fitted into one hook inner surface recess 17a, and an outer cylindrical inner diameter space 21b that accommodates the inner cylindrical body. The inner cylindrical body includes an inner cylindrical protrusion 22g that can be fitted into the other hook inner surface recess 17b, an annular groove 22e for locking the cable tie, and an inner cylindrical inner diameter space 22b that accommodates the compression spring. When the compression spring is compressed so that its axial length is shorter than the hacker inner width IW, the outer cylindrical protrusion and the inner cylindrical protrusion are fitted into the respective hook inner surface recesses, thereby achieving an attached state, which is held in place by the cable tie locked in the annular groove.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a hacker used to lift and transport work (loads such as steel plates, structural steel, and steel pipes), and more specifically to a hacker and a device for preventing slings such as wires and slings from falling off from the sling part. [Background technology]

[0002] A lifting device called a hacker is used to lift and transport workpieces (see Patent Document 1). The hacker (Fig. 1) described in Patent Document 1 is a two-jaw type formed by hot or cold forging and bending killed steel, with a pair of hooks extending approximately parallel to each other at a specified distance from both ends of the sling part, which is formed in a roughly inverted U shape when viewed from the front, and the tip of each hook is bent at a specified angle (for example, about 90 degrees) to form a claw.

[0003] Figure 2 of Patent Document 1 shows an example of using a pair of these hackers to lift a square steel pipe (column). A sling chain, wire rope, or other lifting material connected via a coupling to a hanging ring suspended from a crane is passed through the sling of the hacker, and the claws of the hacker are inserted deep into the inner diameter space from both ends of the square steel pipe, and the square steel pipe W is then lifted with the crane, with the upper surfaces of the claws of the hacker engaging with the upper inner surface of the square steel pipe, allowing the square steel pipe W to be lifted and transported.

[0004] When the crane is lowered to hoist the workpiece (in this example, a square steel pipe) to a designated location and the hacker is removed from the workpiece, if the hoisting material is loose, or when the hacker is being stored, the hoisting material attached to the sling part may slip through between the pair of hook parts and come off the hacker.To prevent this, a detachable stopper 1 is detachably mounted on the hacker.

[0005] The stopper provided in the hacker described in Patent Document 1 will be described with reference to Figure 9 (which is substantially the same as Figure 8 of Patent Document 1). This stopper 1 includes a stopper bolt 2, a stopper nut 3 that threadably mounts the stopper bolt 2 so that it can move back and forth, and a movable nut 4 that threadably mounts the stopper bolt 2 between the stopper bolts 2 and 3 so that it can move back and forth. A round washer 5 is fixed to the outer surface of the stopper bolt 2, and the outer end shank 2a of the stopper bolt 2 protrudes outward beyond the round washer 6a. Similarly, a round washer 6 is fixed to the outer surface of the stopper nut 3, and the outer end shank 3a of the stopper nut 3 protrudes outward beyond the round washer 6. The main shank 2b that protrudes inward from the stopper bolt 2 is inserted into and threadedly engages with the female thread 3b of the stopper nut 3.

[0006] This stopper 1 has its shortest axial length when the stopper bolt 2 is screwed all the way into the stopper nut 3 with the moving nut 4 tightly attached therebetween (Fig. 9(a)), and the axial length of the stopper 1 at this time is slightly shorter than the distance between the inner surfaces 7a and 7b of the hooks of the hacker (the width inside the hacker). This makes the stopper 1 detachable from the hacker, so with the stopper 1 removed, it is easy to hook a sling or other hanging material to the sling when lifting a workpiece, and to remove the material from the sling after the workpiece has been lowered to the designated location.

[0007] From this state, when the retaining nut 3 is rotated in the direction to loosen it relative to the retaining bolt 2, the retaining bolt 2 and the retaining nut 3 move away from each other, gradually lengthening their axial lengths, and as shown in Figure 9(b), the outer end shank 2a of the retaining bolt 2 enters the recess 8a formed in one hook inner surface 7a, and the outer end shank 3b of the retaining nut 3 enters the recess 8b formed in the other hook inner surface 7b. At this time, the round washers 5, 6 provided on both ends of the retainer 5 come into close contact with both hook inner surfaces 7a, 7b.

[0008] From this state, moving the moving nut 4 along the main shaft 2b of the locking bolt 2 and tightening it until it comes into close contact with the locking nut 3 prevents the locking nut 3 from rotating in the loosening direction, and the locking device 1 is fixed between the hook inner surfaces 7a and 7b (Fig. 9(c)). This prevents the sling chain, wire rope, or other hanging material attached to the sling part from accidentally coming off the hacker when the work is landed after being lifted and transported using the hacker and then released into an unloaded state. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-098387 Summary of the Invention [Problem to be solved by the invention]

[0010] The present applicant has been manufacturing and selling hackers using the above-described locking device for many years and has confirmed that it provides a satisfactory locking effect, but has found that there is still room for improvement. The locking device described above moves the locking nut 3 away from the locking bolt 2, bringing the round washers 5, 6 attached to its outer surface into close contact with the hook inner surfaces 7a, 7b, and maintaining this positional relationship with the movable nut 4. However, if the locking nut 3 is turned too hard, the round washers 5, 6a press against the hook inner surfaces 7a, 7b with too much force, deforming the hacker in a direction that widens the gap between the hook inner surfaces 7a, 7b (the hacker's internal width). Conversely, if the locking nut 3 is not turned enough, a gap forms between the round washers 5, 6 and the hook inner surfaces 7a, 7b, resulting in rattles and loud noises during lifting and transport. To prevent these problems, proper torque control is required when turning the locking nut 3, but this is a difficult task in the workplace.

[0011] Therefore, the problem that the present invention aims to solve is to provide a new type of hacker anti-detachment device that is easy for workers to install and remove and that can provide good and reliable anti-detachment effects, and a hacker equipped with such an anti-detachment device. [Means for solving the problem]

[0012] To solve this problem, the present invention of claim 1 provides a locking device for a hacker in which the upper ends of a pair of hooks are connected and closed by a sling, and the locking device is configured to be attachable and detachable between the pair of hooks. The locking device comprises an outer cylindrical body, an inner cylindrical body, a compression spring, and a retaining member. The outer cylindrical body has an outer cylindrical protrusion protruding from its outer end that can fit into a recess formed on the inner surface of one of the hooks, and an inner diameter space formed in the outer cylindrical body that can accommodate the inner cylindrical body. The inner cylindrical body has an inner cylindrical protrusion protruding from its outer end that can fit into a recess formed on the inner surface of the other hook, and a locking portion formed in a predetermined axial position that can lock the locking member, and an inner diameter space formed in the inner cylindrical body that can accommodate the compression spring. When the compression spring is accommodated in the inner diameter space and the inner cylindrical body is accommodated in the outer diameter space, when the compression spring contracts against its spring force, the axial length from the outer end of the outer cylindrical protrusion to the outer end of the inner cylindrical protrusion becomes smaller than the inner width of the hacker, allowing it to be attached. When the compression spring recovers and extends from this attachable state due to its spring force, the anti-detachment device enters an attached state in which the outer tube protrusion is fitted into the recess on the inner surface of one of the hook portions and the inner tube protrusion is fitted into the recess on the inner surface of the other hook portion, and this attached state is maintained by a retaining member engaged with the engaging portion of the inner tube body.

[0013] The present invention of claim 2 is characterized in that, in the hacker anti-detachment device described in claim 1, the inner diameter space of the inner cylinder has an inner diameter approximately the same as the outer diameter of the compression spring, and the inner diameter space of the outer cylinder has an inner diameter approximately the same as the outer shape of the inner cylinder.

[0014] The present invention of claim 3 is characterized in that, in the hacker anti-detachment device described in claim 2, a spring tip accommodating portion having an inner diameter approximately the same as the outer diameter of the compression spring is formed continuous with the inner diameter space of the outer tube.

[0015] The present invention of claim 4 is characterized in that, in the hacker anti-detachment device described in any of claims 1 to 3, the locking portion of the inner cylinder is an annular groove formed at a predetermined axial position of the inner cylinder, and the position retaining member is a cable tie that can be locked into this annular groove.

[0016] The present invention according to claim 5 is a hacker equipped with the anti-detachment device according to any one of claims 1 to 3. [Effects of the Invention]

[0017] According to the present invention, the anti-detachment device attached to the hacker is maintained by a retaining member engaged with the locking portion of the inner cylinder. Therefore, even if an external force acts on the anti-detachment device, the device can be stably held in place as long as the retaining member does not come off the locking portion. Even if the retaining member comes off the locking portion, the force of the compression spring keeps the outer cylinder protrusion and the inner protrusion engaged in the recess on the inner surface of the hook portion. Therefore, the anti-detachment device will not easily come off the hacker unless an external force is applied in a direction that shortens the axial length against the spring force. Therefore, even if a sling chain, wire rope, or other suspending material becomes loose when a workpiece is lowered at a predetermined location using a hacker equipped with the anti-detachment device of the present invention, the suspending material will not slip through the pair of hooks and come off the hacker, ensuring safety.

[0018] According to the present invention of claim 2, a predetermined axial length range on one end side of the compression spring is tightly accommodated in the inner diameter space of the inner cylinder, and the inner cylinder body is tightly accommodated in the inner diameter space of the outer cylinder, and the outer cylinder body and the inner cylinder body are essentially integrated together, and will not easily come apart unless you try to pull them apart forcefully, making them easy to handle and reducing the risk of them being lost.

[0019] According to the present invention of claim 3, the other end of the compression spring is tightly housed in the spring tip housing of the outer cylinder body, so that the outer cylinder body and the inner cylinder body are more tightly integrated and are less likely to come apart, further improving ease of handling and loss prevention.

[0020] According to the present invention as set forth in claim 4, a preferred embodiment is provided that uses a cable tie that is inexpensive and easily available.

[0021] According to the present invention as set forth in claim 5, a hacker that is excellent in safety and ease of use is provided. [Brief explanation of the drawings]

[0022] [Figure 1] 1A and 1B are perspective views of a hacker according to one embodiment of the present invention; [Figure 2] FIG. 2 is an exploded view of the anti-detachment device used in this hacker. [Figure 3] 2 is an enlarged view showing the outer cylinder body of the anti-detachment device of FIG. 1 alone. FIG. [Figure 4] 2 is an enlarged view showing the inner cylinder body of the anti-detachment device of FIG. 1 alone. FIG. [Figure 5] 2 is an enlarged view showing the compression spring (unloaded) of the anti-detachment device of FIG. 1 alone. FIG. [Figure 6] 2 is a diagram showing the state in which the anti-detachment device of FIG. 1 is attached to a hacker (attached state). FIG. [Figure 7] 2 is a diagram showing a state in which a compression spring is contracted (compressed state) in the fall-off prevention device of FIG. 1. FIG. [Figure 8] 10A and 10B are perspective views showing an example of how a hacker uses the device. [Figure 9] 1A to 1C are diagrams showing the configuration and usage of a hacker removal prevention device according to the prior art. BEST MODE FOR CARRYING OUT THE INVENTION

[0023] A hacker locking device according to one embodiment of the present invention will be described with reference to FIGS.

[0024] Hacker 10 has basically the same shape and structure as the hacker described in Patent Document 1. That is, hacker 10 has hook portions 11a and 11b that are generally U-shaped in side view and extend generally parallel to each other with a predetermined gap (hacker inner width) IW between them, and the upper ends of hook portions 11a and 11b are connected to each other by sling portion 12 that is generally inverted U-shaped in front view to form a closed shape. The tips of hook portions 11a and 11b are bent inward at an angle of approximately 90 degrees to form claw portions 13a and 13b.

[0025] Its usage is also substantially the same as that of the hacker described in Patent Document 1, and not only is it used to insert the tip claws 13a, 13b of the hook portions 11a, 11b into the inner diameter space of a square steel pipe (column) to horizontally suspend and transport it, as shown in Figure 2 of Patent Document 1, but it can also be used to horizontally suspend and transport a flat steel plate W1 (Figure 8(a)) or an H-shaped steel W2 (Figure 8(b)) by hoisting two pairs of hackers 10, 10; 10, 10 with a crane 16 via a balance 14 and a suspending material 15 such as a sling chain or a wire rope, as shown in Figure 8 of the present application.

[0026] A new anti-detachment device 20, which is completely different from the anti-detachment device 5 (FIG. 9) already described and employed in the hacker described in Patent Document 1, is detachably attached to the hacker 10. The configuration and operation of this anti-detachment device 20 will be described in detail below, particularly with reference to FIGS. 2 to 7.

[0027] This retaining device 20 is composed of four members: an outer cylindrical body 21, an inner cylindrical body 22, a compression spring 23, and a binding band 24. The outer cylindrical body 21 and the inner cylindrical body 22 are substantially cylindrical bodies having a common axis X.

[0028] The outer cylinder 21 has an outer cylinder main body 21a (axial length L1), and the outer cylinder main body 21a has an outer cylinder inner diameter space 21b (axial length L2). The outer cylinder inner diameter space 21b opens at the inner end (right end in the figure) 21c of the outer cylinder main body 21a, extends outward (leftward in the figure) from the inner end 21c with an inner diameter R1 for an axial length L2, and extends from its bottom with an inner diameter R2 (<R1) for a slight axial length L3 to form a spring tip accommodating portion 21d.

[0029] An outer cylinder protrusion 21f that protrudes further outward is provided at the outer end (left end in the figure) 21e of the outer cylinder main body 21a. The outer cylinder protrusion 21f has a shape and size that can be fitted into a substantially circular concave portion 17a formed on the inner surface of one hook portion 11a of the hocker 10.

[0030] The inner cylinder 22 has an inner cylinder main body 22a. The inner cylinder main body 22a has an outer diameter R3 that is substantially the same as or slightly smaller than the inner diameter R1 of the outer cylinder inner diameter space 21b, and has an axial length L4 that is substantially the same as or slightly smaller than the axial length L2 of the inner diameter space 21b of the outer cylinder 21. Therefore, substantially the entire inner cylinder main body 22a can be accommodated in the outer cylinder inner diameter space 21b.

[0031] The inner cylinder main body 22a has an inner cylinder inner diameter space 22b. The inner cylinder inner diameter space 22b opens at the inner end (left end in the figure) 22c of the inner cylinder main body 22a, and extends outward (rightward in the figure) from the inner end 22c for an axial length L5. The inner end of the inner cylinder inner diameter space 22b is slightly narrowed in diameter to form a spring tip accommodating portion 22d.

[0032] An annular groove 22e with an outer diameter R4 that is slightly smaller than the outer diameter R3 is recessed at a predetermined axial position of the inner cylinder main body 22a, and a binding band 24 can be attached to this annular groove 22e. The inner cylinder main body 22a consists of three parts: a portion 22a1 (outer diameter R3, axial length L6) inside the annular groove 22e, the annular groove 22e (outer diameter R4, groove width L7), and a portion 22a2 (outer diameter R3, axial length L8) on the outer end side of the annular groove 22e. Therefore, L4 = L6 + L7 + L8.

[0033] An outwardly projecting protrusion 22g is provided at the outer end 22f (the right end in the drawing) of the inner cylinder body 22a. This protrusion 22g has a shape and size that allows it to fit into a substantially circular recess 17b formed on the inner surface of the other hook portion 11b of the hacker 10.

[0034] The compression spring 23 has an outer diameter R5 that is approximately the same as or slightly smaller than the inner diameter R2 of the spring tip accommodating portion 21d of the outer tube main body 21a and the inner diameter (no symbol) of the spring tip accommodating portion 22d formed at the rear end of the inner tube inner diameter space 22b, and has an axial length L9 (unloaded) that is sufficiently larger than the axial length L5 of the inner tube inner diameter space 22b. Therefore, the compression spring 23 has one end within a predetermined axial length range tightly accommodated in the spring tip accommodating portion 22d at the rear end of the inner cylinder inner diameter space 22a, the inner cylinder main body 22a holding the compression spring 23 in this manner is tightly accommodated in the outer cylinder inner diameter space 21b, and the other end of the compression spring 23 is tightly accommodated in the spring tip accommodating portion 21d at the rear end of the outer cylinder inner diameter space 21b, so that it is essentially integrated with the outer cylinder body 21 and the inner cylinder body 22 and will not easily come apart unless you try to pull it apart forcefully, making it easy to handle and reducing the risk of it being lost.

[0035] With this anti-slip device 20 not attached to the hacker 10, a sling 14 (FIG. 8) such as a wire is passed between the hook portions 11a and 11b and set on the sling portion 12, and then the anti-slip device 20 is attached to the hacker 10. As described above, in this anti-slip device 20, one end of the compression spring 23 is tightly housed in the spring tip housing portion 22d at the rear end of the inner cylinder inner diameter space 22a, the inner cylinder body 22a is tightly housed in the outer cylinder inner diameter space 21b, and the other end of the compression spring 23 is tightly housed in the spring tip housing portion 21d at the rear end of the outer cylinder inner cylinder space, with the outer cylinder body 21, inner cylinder body 22, and compression spring 23 integrated together, and a binding band 24 is provided separately.

[0036] While grasping the outer cylinder body 21a and inner cylinder body 22a of this anti-detachment device 20 (outer cylinder body 21 + inner cylinder body 22 + compression spring 23) with both hands, move them toward each other against the spring force of the compression spring 24 until the axial length from the outer end of the outer cylinder protrusion 21e to the outer end of the inner cylinder protrusion 22e reaches a dimension L10 that is approximately equal to or slightly smaller than the hacker inner width IW (Figure 7). In this compressed state, almost the entire inner cylinder body 22a is housed within the outer cylinder inner diameter space 21b.

[0037] While maintaining the compressed state, insert the anti-detachment device 20 (outer tube body 21, inner tube body 22, and compression spring 23) between the hook portions 11a and 11b of the hacker 10, roughly align it with the recesses 17a and 17b on the inner surface of the hook portions, and then release the outer tube body 21a and the inner tube body 22a to release the compression spring 23. This generates a spring force that moves the outer tube body 21 and the inner tube body 22 away from each other, resulting in an attached state in which the outer tube protrusion 21f enters the recess 17a on the inner surface of the hook portion 11a and the inner tube protrusion 22g enters the recess 17b on the inner surface of the hook portion 11b. After confirming that this attached state has been achieved, wrap a cable tie 24 around the annular groove 22d of the inner tube body 22 to secure it in place (Figure 6). The axial length of the anti-detachment device 20 at this time is equal to the inner width IW of the hacker.

[0038] In this attached state, even if an external force acts on the anti-detachment device 20, the attached state is stably maintained unless the cable tie 24 breaks and comes off the annular groove 22e. Even if the cable tie 24 breaks and comes off the annular groove 22e, the spring force of the compression spring 23 keeps the outer tube protrusion 21f and the inner protrusion 22g, respectively, engaged in the recesses 17a and 17b on the inner surface of the hook portion. Therefore, the anti-detachment device 20 will not easily come off the hacker 10 unless an external force that shortens the axial length against the spring force is applied. Therefore, when the anti-detachment device 20 is properly attached to the hacker 10, even if the suspending member 15 is loose, it will not pass between the pair of hook portions 11a and 11b and come off the hacker 10, ensuring safety, even if the suspending member 15 is loose.

[0039] The removal of the anti-detachment device 20 from the hacker 10 after the workpiece has been lowered at a predetermined location can be performed in substantially the same manner as the installation described above. That is, the cable tie 24 is removed from the attached anti-detachment device 20, and while grasping the outer tube body 21a and the inner tube body 22a with both hands, the outer tube body 21a and the inner tube body 22a are moved toward each other against the spring force of the compression spring 24 until the axial length from the outer surface of the outer tube projection 21f to the outer surface of the inner tube projection 22g is approximately equal to or slightly smaller than the hacker inner width IW. The anti-detachment device 20 can then be removed from the hacker 10 by pulling it out from between the hook portions 11a and 11b. As described above, the outer tube body 21, the inner tube body 22, and the compression spring 23 are substantially integrated after removal and do not easily come apart unless a strong attempt is made to pull them apart. This makes the anti-detachment device 20 less likely to come apart, easier to handle, and less likely to be lost.

[0040] Although one embodiment of the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to this embodiment and can be implemented with a wide variety of modifications and changes within the scope of the invention as defined by the claims.

[0041] For example, in the above embodiment, the attached state of the anti-detachment device 20 (FIG. 3) is maintained by wrapping and tying the cable tie 24 around the annular groove 22d of the inner cylindrical body 21. While using cable ties, which are inexpensive and readily available, offers the advantage of this configuration, other configurations may be adopted as long as they can maintain the attached state. For example, a configuration in which a radially extending hole is formed at a predetermined axial position of the inner cylindrical body and a pin is inserted into this through-hole to maintain the attached state may also be adopted. In this case, the through-hole needs to be formed outward from the bottom of the inner cylindrical inner diameter space 22b that houses the compression spring 23 to prevent the pin inserted into the through-hole from interfering with the compression spring. [Explanation of symbols]

[0042] 10. Hacker 11a, 11b Hook part 12 Sling section 13a, 13b Tip claws 17a, 17b Recessed portion on the inner surface of the hook 20 Anti-detachment device 21 Outer cylinder 21a main body 21b Outer cylinder inner diameter space 21c inner edge 21d Spring tip housing 21e Outer edge 21f protrusion 22 Inner cylinder 22a main body 22b Inner cylinder inner diameter space 22c inner edge 22d Spring tip housing 22e Annular groove (locking part) 22f outer edge 22g protrusion 23 Compression spring 24 Cable tie (retaining member)

Claims

1. In a hacker in which the upper ends of a pair of hooks are connected and closed by a sling part, a detachment prevention device is provided which is attachable and detachable so as to span between the pair of hooks, and which is composed of an outer cylindrical body, an inner cylindrical body, a compression spring, and a holding member. The outer cylinder has an outer cylinder protrusion protruding from its outer end, which can be fitted into a recess formed on the inner surface of one of the hook portions, and an inner diameter space of the outer cylinder capable of accommodating the inner cylinder is formed. The inner cylinder has an inner cylinder protrusion protruding from its outer end that can be fitted into a recess formed on the inner surface of the other hook portion, a locking portion that can lock a holding member at a predetermined axial position, and an inner diameter space that can accommodate a compression spring. A hacker anti-detachment device characterized in that, when the compression spring is housed in the inner diameter space of the inner tube and the inner tube body is housed in the inner diameter space of the outer tube, when the compression spring contracts against its spring force, the axial length from the outer end of the outer tube protrusion to the outer end of the inner tube protrusion becomes smaller than the inner width of the hacker, making it possible to attach it, and when the compression spring recovers and extends from this attachable state due to its spring force, the outer tube protrusion is fitted into the recess on the inner surface of one of the hook portions and the inner tube protrusion is fitted into the recess on the inner surface of the other hook portion, making it possible to attach it, and this attached state is maintained by a retaining member engaged with the engaging portion of the inner tube body.

2. 2. A hacker locking device according to claim 1, wherein the inner diameter space of the inner cylinder has an inner diameter substantially equal to the outer diameter of the compression spring, and the inner diameter space of the outer cylinder has an inner diameter substantially equal to the outer diameter of the inner cylinder.

3. 3. A hacker stopper device according to claim 2, wherein a spring tip accommodating portion having an inner diameter substantially the same as the outer diameter of the compression spring is formed adjacent to the inner diameter space of the outer cylinder.

4. A hacker anti-detachment device as described in any one of claims 1 to 3, characterized in that the locking portion of the inner cylindrical body is an annular groove formed at a predetermined axial position of the inner cylindrical body, and the position retaining member is a cable tie that can be locked in this annular groove.

5. A hacker equipped with the anti-detachment device according to any one of claims 1 to 3.

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