Hook with anti-detachment mechanism

Abstract

To enable unlocking operation of a stopper without removing fingers from the palm in a hook with a mechanism for preventing the stopper from coming off, which opens an opening by rotating the stopper upward. [Solution] The hook 1 with a release prevention mechanism has a release stopper 4 and a U-shaped lock lever 6 that engages with the release stopper 4 to hold it in the closed position, and is unlocked by rotating the lock lever 6 counterclockwise around the lever support shaft 7. The lock lever 6 is rotatable on the back side of the hook body 2, and a line R extending horizontally from the center of the lever support shaft 7 passes below the bottom end position p.

Description

[Technical Field]

[0001] The present invention relates to a hook used for slinging and transporting work, and more particularly to a hook with a mechanism for preventing the sling from coming off. [Background technology]

[0002] Some hooks with detachment prevention mechanisms, such as those shown in Patent Document 1, have a single-opening latch, known as a hook stopper or latch, rotatably attached to the base end of the hook body, which can be rotated downward around a pivot point to open an opening for inserting and removing slings. Rotating the latch downward places the latch inside the opening, limiting the working space. On the other hand, hooks with detachment prevention mechanisms, such as those shown in Patent Documents 2-5, rotate the latch upward around a pivot point to open the opening. By rotating the latch upward, the working space within the opening is not limited, and the opening can be made larger than if the latch were rotated downward, making them superior to the hooks with detachment prevention mechanisms shown in Patent Document 1.

[0003] The hooks with detachment prevention mechanisms disclosed in Patent Documents 1 to 5 are equipped with a lock lever that holds the detachment stopper in a position where the opening is closed and prevents the detachment stopper from opening from that position. The lock lever is designed to lock the detachment stopper from rotating in the opening direction. The lock is released by manually rotating the lock lever. Furthermore, Figure 4 of Patent Document 6 discloses a hook (a so-called "latch lock") in which the base end and the detachment stopper are integrated and pivotally attached to the hook member by a pin. With a latch lock, when a load is hung, the base end is hung by a crane, lowering the detachment stopper, and the weight of the load hanging on the hook member raises the hook tip, closing the opening at the hanging point. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-147969 [Patent Document 2] Japanese Patent Publication No. 2021-169362 [Patent Document 3] Japanese Unexamined Patent Publication No. 50-89746 [Patent Document 4] Japanese Utility Model Application Publication No. 59-195176 [Patent Document 5] Jikko No. 50-7657 [Patent Document 6] Japanese Patent Application Publication No. 8-301571 Summary of the Invention [Problem to be solved by the invention]

[0005] In the hook with a detachment prevention mechanism disclosed in Patent Document 1, the lock lever provided on the back side of the hook body is unlocked by moving its tip in a direction that overlaps the hook body. In the hook with a detachment prevention mechanism disclosed in Patent Documents 2-5, the lock lever is housed in a detachment stopper, and the rotation axis of the lock lever is provided on the detachment stopper side. When the detachment stopper closes the opening, the lock lever is housed in the detachment stopper. In the hook with a detachment prevention mechanism disclosed in Patent Documents 2 and 3, the lock lever is rotated upward to unlock. Meanwhile, in the hook with a detachment prevention mechanism disclosed in Patent Documents 4 and 5, the lock lever is rotated downward to unlock.

[0006] In the case of the hook with a release prevention mechanism shown in Patent Document 1, when the lock is released by moving the tip of the lock lever in a direction that overlaps with the hook body, the lock can be easily released if the tip of the lock lever on the back side of the hook body receives an impact that presses it toward the hook body.

[0007] Furthermore, as with the hooks with detachment prevention mechanisms shown in Patent Documents 2 and 3, when rotating the lock lever upward, it is necessary to pull up the lock lever with the fingers. This poses a problem when wearing thick gloves, making it difficult for the fingers to engage the lock lever. Furthermore, the fingers must be separated from the palm and moved independently.

[0008] Furthermore, when rotating the lock lever downward, as with the hooks with anti-disconnection mechanisms shown in Patent Documents 4 and 5, the user must remove their fingers from the palm of their hand and insert them into the opening where the sling is located to operate the lock lever, which poses problems not only in terms of operability but also in terms of safety.The latch lock disclosed in Patent Document 6 has a problem in that the base end that bears the load of the suspended load and the hook member are separated and pivotally connected by a pin, resulting in a complex structure.

[0009] To provide a hook with a prevention mechanism that allows the locking of the stopper to be released without removing the fingers from the palm of the hand, in a hook with a removal prevention mechanism that opens an opening by rotating the stopper upward around a rotation fulcrum. [Means for solving the problem]

[0010] In order to solve the above problems, the hook with a disengagement prevention mechanism of the present invention has a disengagement prevention device that bridges the opening between the base end side and the tip end side of the hook body and has a pivot shaft as a rotation center on the base end side, and a lock lever that engages a locking part with an engaging part of the disengagement prevention device to hold the disengagement prevention device in a position to close the opening, and disengages the locking part from the engaging part to rotate the disengagement prevention device upward to open the opening, The lock lever has a U-shape that surrounds the hook body on the back side with left and right pieces and a back part that connects the left and right pieces, and is rotatable on the back side of the hook body around a lever support shaft located below the pivot shaft as a rotation center, A line extending horizontally from the center of the lever support shaft passes below the lower end position of the spine when the locking portion and the engaging portion are engaged. [Effects of the Invention]

[0011] To unlock the hook with the detachment prevention mechanism of the present invention, the user wraps the palm of the hand around the hook body from the outside, holds the lock lever between the thumb and index finger, and places the pad of the thumb against the shoulder, allowing the user to safely unlock the hook without removing or moving the fingers from the palm. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a side view of the hook with the detachment prevention mechanism of the present invention. [Figure 2] FIG. 10 is a perspective cross-sectional view of a hook with a detachment prevention mechanism. [Figure 3] FIG. 10 is a perspective view of a hook with a detachment prevention mechanism. [Figure 4] 10A and 10B are explanatory diagrams illustrating how to use a hook with a mechanism for preventing detachment. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of a hook with a detachment prevention mechanism of the present invention will be described below with reference to FIGS. 1 to 4 of the accompanying drawings. In FIG. 1, the hook with a detachment prevention mechanism 1 is exemplified as an eye hook having a loop at a base end 2a on the upper side of the hook body 2 for connecting a crane hoisting wire, string, or the like. The base end 2a is a part formed integrally with the hook body 2. FIG. 1A shows the hook in a locked state, and FIG. 1B shows the hook in an unlocked state. The hook body 2 includes a detachment stopper 4 that bridges an opening 3, which is the space between the base end 2a and the tip end 2b of the hook body 2, a pivot 5 that rotatably attaches the detachment stopper 4 to the base end 2a of the hook body 2, and a lock lever 6 that holds the detachment stopper 4 in a position that closes the opening 3 (locked state). A lever support shaft 7 is provided below the pivot 5. The lever support shaft 7 serves as the rotation center of the lock lever 6, allowing the lock lever 6 to rotate on the back side of the hook body 2 (the opposite side of the opening 3 across the hook body 2). The lock lever 6 has a pin-shaped lock portion 8 at a position away from the lever support shaft 7. The hook body 2 has an elongated hole 2c so that the lock portion 8 can move in an arc centered on the lever support shaft 7 when the lock lever 6 rotates.

[0014] Fig. 2 is a perspective side view of the hook 1 with a disengagement prevention mechanism. Fig. 2A shows the locked state, and Fig. 2B shows the unlocked state. The disengagement prevention device 4 has a body 4a and a tail 4b on the opposite side of the pivot 5, with the pivot 5 sandwiched between them. The tail 4b is provided with an engaging portion 4c that engages with the locking portion 8. A spring body 9 (double torsion spring) biases the body 4a of the disengagement prevention device 4 so that it rotates around the pivot 5 toward the upper side of the base end 2a (counterclockwise in the figure).

[0015] A spring body 10 is disposed between the lock lever 6 and the hook body 2. One end of the spring body 10 engages with the protrusion 2d on the hook body 2, and the other end engages with the protrusion 6e on the lock lever 6. The spring body 10 biases the lock lever 6 in a direction that rotates it around the lever support shaft 7 toward the base end 2a (clockwise in the drawing).

[0016] For the three-dimensional shape of the lock lever 6, please refer to Figure 3B. The lock lever 6 has left and right pieces 60, 61 and a back portion 62 connecting the pieces 60, 61, and is formed into a U-shape that surrounds the hook body 2 on the back side. Specifically, the pieces 60, 61 and the back portion 62 are formed by bending a metal plate into a U-shape. In the locked state of Figure 2A, the engaging portion 4c of the release stopper 4 engages with the lock portion 8 of the lock lever 6. In the unlocked state of Figure 2B, the lock lever 6 is rotated counterclockwise. The engaging portion 4c of the release stopper 4 disengages from the lock portion 8, and the release stopper 4 rotates counterclockwise due to the spring body 9, opening the opening 3.

[0017] 2B, the shoulder 6b of the lock lever 6 is pulled downward. The shoulder 6b is the upper edge of the pieces 60 and 61 of the lock lever 6.

[0018] In the locked state shown in FIG. 2A , the outer surface 6a of the back portion 62 of the lock lever 6 is inclined by an angle θ in the vertical direction. When the locking portion 8 and the engaging portion 4c are engaged, a line R extending horizontally from the center of the lever support shaft 7 passes below the lower end position p of the back portion 62. More preferably, a line r extending from the center of the lever support shaft 7 perpendicular to the line extending downward from the lower end position p of the outer surface 6a of the back portion 62 while maintaining its inclination passes at or below the lower end position p (below the lower end position p in the figure). Therefore, even if a force F acts at the lower end position p to press the lock lever 6 toward the hook main body 2, the lock lever 6 will not rotate counterclockwise due to such force F.

[0019] Figure 3 is a perspective view of the hook 1 with a release prevention mechanism, with Figure 3A showing the unlocked state and Figure 3B showing the disassembled state. The pivot 5 is inserted through a through-hole 2f drilled below the base end 2a of the hook main body 2, the coil 9a of the spring body 9, and a hole 4e drilled in the release prevention device 4. The lever support shaft 7 is inserted through a hole 6f formed in the lock lever 6 and a hole 2g drilled in the hook main body 2 below the through-hole 2f. The locking part 8 is inserted through a hole 6g formed in the lock lever 6 and an elongated hole 2c formed in the hook main body 2.

[0020] In the description of FIG. 1, the anti-detachment device 4 was described as having a body portion 4a and a tail portion 4b on the opposite side of the pivot 5. More specifically, as shown in FIG. 3A, the body portion 4a includes a pair of opposing side walls 40, 40 and a cover wall 41 provided between the opposing side walls 40, 40. The pair of opposing side walls 40, 40 are spaced apart by a gap 4g, and the cover wall 41 closes the gap 4f at the tip of the body portion 4a, thereby cooperating with the opposing side walls 40, 40 to surround the tip portion 2b of the hook body 2. The tail portion 4b also specifically includes a pair of opposing side walls 42, 42. The pair of opposing side walls 42, 42 are spaced apart by a gap 4g from the pair of opposing side walls 40, 40, respectively. The gap 4f between the pair of opposing side walls 40, 40 allows a portion of the base end 2a to fit in when the anti-detachment device 4 is rotated upward by the spring body 9. This allows the stopper 4 to rotate widely, and the opening 3 to be opened widely.

[0021] The arm portions 9c of the spring body 9 are housed in the stop portions 4d provided on a pair of opposing side walls 40, 40. In addition, the center portion 9b of the spring body 9 abuts against the contact surface 2h of the hook body 2. This allows the spring body 9 to bias the stopper 4 counterclockwise around the pivot 5.

[0022] The upper edge 6c of the back portion 62 is shaped to follow the contour of the base end portion 2a when in the locked state, in order to create a silhouette that slopes down continuously from the surface of the base end portion 2a to the outer surface 6a of the back portion 62 with as few steps as possible (see FIG. 1A).

[0023] Figure 4 shows how to unlock (Figure 4B) a hook with a locking mechanism (Figure 4A). The hook body 2 is held in one palm, the lock lever 6 is pinched between the thumb and index finger, and the pad of the thumb or index finger is placed against the shoulder 6b. The palm of the other hand is placed against the locking device 4 (Figure 4A). The locking device 4 is held down to prevent the locking device 4 from bouncing up after being released by the spring 9. Pulling one palm down disengages the locking portion 8 from the engaging portion 4c of the locking device 4. Releasing the other palm rotates the locking device 4, opening the opening 3 (Figure 1B). While it is possible to operate the locking lever 6 by firmly pinching the outer surfaces 6d of the arms 60 and 61 from both sides, the outer surfaces 6d are flat and have little friction, making operation difficult. Placing the pads of the thumb or index finger against the shoulder 6b is much easier.

[0024] According to the hook 1 with the release prevention mechanism, even if a force is applied pressing the outer surface 6a of the back portion 62 toward the hook body 2, the force only moves the hook body 2 clockwise around the pivot 5, and the hook is not unlocked. To unlock the hook, the user wraps the palm of their hand around the hook body 2 from the outside, holds the lock lever 6 between their thumb and index finger, and places the pad of the thumb against the shoulder portion 6b, allowing the user to safely unlock the hook without having to move their fingers away from the palm. [Explanation of symbols]

[0025] 1. Hook with anti-detachment mechanism 2 Hook body 2a Proximal end 2b Tip 2c long hole 2d convex 2h contact surface 3 aperture 4 Stopper 4a Torso 4b Tail 4c Engagement part 4d stop 4f, 4g intervals 5 Axis 6 Lock lever 6a Outer surface 6b Shoulder 6c Top 6d outer surface 6e protruding 7 Lever support shaft 8 Locking section 9 Spring body 10 Spring body 40,40, 42,42 Opposite side walls 41 Cover Wall 60, 61 one side 62 Back

Claims

1. A hook with a disengagement prevention mechanism includes a disengagement stopper that bridges an opening between the base end side and the tip end side of a hook body and has a pivot shaft as a rotation center on the base end side, and a lock lever that holds the disengagement stopper in a position to close the opening by engaging a locking part with an engaging part of the disengagement stopper, and disengages the locking part from the engaging part to rotate the disengagement stopper upward to open the opening, The lock lever has a U-shape that surrounds the hook body on the back side with left and right pieces and a back part that connects the left and right pieces, and is rotatable on the back side of the hook body around a lever support shaft located below the pivot shaft as a rotation center, A hook with a detachment prevention mechanism, characterized in that a line extending horizontally from the center of the lever support shaft passes below the lower end position of the back part when the locking part and the engaging part are engaged.

2. In the hook with a detachment prevention mechanism of claim 1, A hook with a mechanism for preventing disengagement is characterized in that a line extending from the center of the lever support shaft perpendicular to an extension line extending downward from the lower end position of the back portion while maintaining the inclination of the outer surface of the back portion passes through the position of the lower end position or below it.

3. In the hook with a detachment prevention mechanism of claim 1, the stopper has a body portion and a tail portion on the opposite side of the pivot axis, the body portion further comprising a pair of first opposing side walls spaced apart by a first predetermined distance, and a cover wall provided between the first opposing side walls; the tail portion includes a pair of second opposing side walls spaced a second predetermined distance apart; A hook with a disengagement prevention mechanism, characterized in that the first gap is defined by a portion of the base end portion that fits into the first gap when the disengagement prevention device is rotated upward.

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