CN111547614A - Anti-decoupling device for hook - Google Patents

Abstract

The present invention provides an anti-releasing hook device for a hook. An installation hole is provided at the lower end of the straight handle, the middle part of the frame is rotatably connected to the installation hole, and one end of the frame is located in the hook and can The other end of the frame extends from the mounting hole to the outside of the hook back, and one end of the positioning plate is rotatably connected with the other end of the frame; when the positioning plate hangs down naturally When the frame is locked, one end of the frame and the hook tip are snapped to the hook mouth to close, so that the hook is in a locked state; moving the positioning plate makes the frame rotate and the other side of the positioning plate One end of the frame is engaged with the hook back, and one end of the frame moves away from the hook tip and moves into the curved hook until the hook opening is opened, so that the hook is in an open state. The anti-decoupling device can achieve positioning in both states of locking and opening, without manual intervention, and when the rigging is heavy, only one person can operate the rigging with both hands.

Description

Anti-decoupling device for hook

technical field

The invention relates to the technical field of hoisting hooks, in particular to an anti-decoupling device for the hook.

Background technique

Hook is the most common type of spreader in lifting machinery, especially crane equipment. The objects to be hoisted are hung into the hooks through rigging, and the objects are transferred with the lifting of the hooks. Due to the needs of safety production, in order to avoid safety accidents caused by the rigging slipping out of the hook during the working process of the crane, the crane hook must be equipped with an anti-release hook device. The standard spring clip-type anti-releasing hook device is adopted. The device relies on the elastic force of the spring to ensure that the opening of the hook is locked. However, the spring is very easy to fail and damage, and it is difficult to replace. After the opening of the hook is opened, the other hand can take out the rigging. When the rigging is heavy and cannot be lifted with one hand, two people are required to cooperate to complete the rigging work, which has potential safety hazards. It is also a waste of manpower, especially in the workplace where frequent rigging is required, and the work efficiency is low.

In view of the above-mentioned problems in the prior art, there is a need for an anti-decoupling device for a hook.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an anti-decoupling device for a hook. The device is not only convenient and quick to install and replace, but also the anti-decoupling device can be positioned in both states after locking and opening, without manual intervention, and when the rigging is heavy, only one person can use both hands to remove the rigging Tool.

In order to achieve the above object, the present invention provides the following technical solutions:

An anti-releasing hook device for a hook, the hook includes a straight handle and a curved hook, the curved hook has a hook tip, the side opposite to the hook tip is a hook back, and the hook tip reaches the straight line. The position between the handles is the hook mouth, and the anti-decoupling device includes a frame and a positioning plate, wherein,

An installation hole is provided at the lower end of the straight handle, the middle part of the frame is rotatably connected with the installation hole, and one end of the frame is located in the hook and can be clamped with the hook tip; The other end extends to the outside of the hook back from the mounting hole, and one end of the positioning plate is rotatably connected to the other end of the frame; rotating the frame can make the other end of the positioning plate and the hook back clamp When the positioning plate hangs down naturally, one end of the frame and the hook tip are snapped to the hook mouth to close, so that the hook is in a locked state; moving the positioning plate can make the The frame rotates and the other end of the positioning plate is snapped with the hook back, and one end of the frame moves away from the hook tip and moves into the hook until the hook opening is opened, so that the hook is in the position of the hook. open state.

Further, in the above-mentioned hook anti-decoupling device, the frame includes an inner frame and an outer frame, the frame is a rectangular structure, and the frame is bent at the mounting hole to form the inner frame and the outer frame. The outer frame, on the frame, from the mounting hole to one end of the frame is the inner frame, and from the mounting hole to the other end of the frame is the outer frame; the positioning One end of the plate is rotatably connected with the outer frame.

Further, in the above-mentioned hook prevention device for hooks, two first sleeves are provided on the frame, and the two first sleeves are arranged opposite to each other, and one end of the first sleeve is connected to the Frame connection, the other end of the first sleeve extends to the inside of the frame, the mounting hole is connected with a screw, both ends of the screw extend out of the mounting hole, and the two ends of the screw extend respectively into one of the first sleeves, and the first sleeves can rotate relative to the screws.

Further, in the above-mentioned hook-releasing prevention device, the width of the inner space of the frame is greater than the width of the largest cross-section of the hook.

Further, in the above-mentioned hook-releasing prevention device, the connection between the outer frame and the inner frame is an arc structure.

Further, in the above-mentioned hook-releasing prevention device, the weight of the outer frame plus the weight of the positioning plate is greater than the weight of the inner frame.

Further, in the above-mentioned anti-decoupling device for a hook, one end of the positioning plate is provided with a second sleeve, and the second sleeve is sleeved on the other end of the frame, so that the positioning plate is connected to the frame. The other end of the frame is rotatably connected.

Further, in the above-mentioned hook-releasing prevention device, the other end of the positioning plate is provided with a groove, and the groove can be matched with the arc surface of the hook back.

Further, in the above-mentioned hook-releasing prevention device, the length of the outer frame is greater than the length of the inner frame.

Further, in the above-mentioned hook-releasing prevention device, a push-pull hook is further included, through which the positioning plate can be pushed and pulled at a long distance so that the hook is in an open or locked state.

It can be seen from the analysis that the present invention discloses an anti-decoupling device for a hook, which can achieve positioning in both locked and open states; the movement of the anti-decoupling device from the open to the locked state relies on the outer frame plus the positioning plate The anti-decoupling device can realize positioning in the locked state, that is, the inner frame is stuck at the hook mouth and is positioned by the positioning plate to prevent the rigging from decoupling; ) The positioning plate realizes the process from locking to opening, and it can also be realized by lifting the outer frame upward; the positioning of the anti-decoupling device in the open state is realized by the groove of the positioning plate being stuck on the hook back; the anti-decoupling device After opening, it can be positioned and released without other manual intervention; when the anti-decoupling device is in the open state to take the rigging, only one person can take the rigging with two hands at the same time.

Description of drawings

The accompanying drawings forming a part of the present application are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. in:

FIG. 1 is a schematic structural diagram of an embodiment of the present invention in a use state.

FIG. 2 is a schematic structural diagram of an embodiment of the present invention in another use state.

FIG. 3 is a schematic structural diagram of an embodiment of the present invention.

FIG. 4 is a schematic structural diagram of a frame according to an embodiment of the present invention.

FIG. 5 is a schematic structural diagram of an inner frame according to an embodiment of the present invention.

FIG. 6 is a schematic diagram of the right side view of FIG. 1 .

FIG. 7 is a schematic structural diagram of a positioning plate according to an embodiment of the present invention.

Description of reference numerals: 1 hook; 11 straight handle; 12 curved hook; 13 hook tip; 14 hook back; 15 mounting hole; 16 hook mouth; 2 frame; 21 inner frame; 22 outer frame; 23 first sleeve; 3 positioning plate; 31 second sleeve; 32 groove.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. The various examples are provided by way of explanation of the invention and do not limit the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment can be used on another embodiment to yield yet another embodiment. Therefore, it is intended that the present invention embrace such modifications and variations as come within the scope of the appended claims and their equivalents.

In the description of the present invention, the terms "portrait", "horizontal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", " The orientations or positional relationships indicated by "top" and "bottom" are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention rather than requiring the present invention to be constructed and operated in a specific orientation, and therefore cannot be understood as Limitations of the present invention. The terms "connected", "connected" and "arranged" used in the present invention should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection; it may be directly connected or indirectly connected through intermediate components. Those of ordinary skill in the art can understand the specific meanings of the above terms according to specific situations.

As shown in FIG. 1 to FIG. 7 , according to an embodiment of the present invention, there is provided an anti-decoupling device for a hook. The hook 1 includes a straight handle 11 and a curved hook 12. The curved hook 12 has a hook tip 13. The side opposite to the hook tip 13 is the hook back 14. The position between the hook tip 13 and the straight handle 11 is the hook mouth 16. The decoupling device includes a frame 2 and a positioning plate 3, wherein a mounting hole 15 is provided at the lower end of the straight handle 11 of the hook 1, the middle of the frame 2 is rotatably connected with the mounting hole 15, and one end of the frame 2 is located in the hook 12 and can The other end of the frame 2 extends from the mounting hole 15 to the outside of the hook back 14, and one end of the positioning plate 3 is rotatably connected with the other end of the frame 2, and the positioning plate 3 plays the role of positioning;

When the positioning plate 3 hangs down naturally, one end of the frame 2 and the hook tip 13 are snapped to the hook opening 16 to be closed, as shown in FIG. 1 , so that the hook 1 is in a locked state. Rotate the frame 2 so that the other end of the positioning plate 3 is engaged with the hook back 14. At this time, one end of the frame 2 leaves the hook tip 13 and moves into the hook 12 until the hook mouth 16 opens, as shown in FIG. 2, so that the hook 1 is open.

Moving the positioning plate 3 can make the frame 2 rotate, and the other end of the positioning plate 3 can be engaged with the hook back 14. When the hook 1 is in the locked state, first move the positioning plate 3 to rotate the frame 2, and the One end leaves the hook tip 13 and moves into the hook 12 until the hook opening 16 is opened, and then the other end of the positioning plate 3 is snapped with the hook back 14 to keep the hook 1 in an open state.

When the hook 1 is in the locked state, the outer frame 22 can also be lifted up to move one end of the frame 2 away from the hook tip 13 and move into the hook 12 until the hook opening 16 is opened, and then the other end of the positioning plate 3 can be opened. It is snapped with the hook back 14 so that the hook 1 is in an open state.

Specifically, when the hook 1 is in the locked state, the positioning plate 3 is moved to rotate the frame 2. Due to the lever principle, one end of the frame 2 moves away from the hook tip 13 and moves into the hook 12 until the hook opening 16 opens, so that the hook 16 is opened. The hook 1 is in an open state, and the rigging in the hook 1 can be taken out from the hook opening 16 at this time. Move the positioning plate 3 so that the positioning plate 3 leaves the hook back 14 and sags naturally. Under the gravity of the positioning plate 3, the frame 2 is rotated. The hook tip 13 is snapped, thereby realizing the locking state of the hook 1 . When putting in the rigging again, put the rigging directly into the hook mouth 16. When the rigging is pressed to one end of the frame 2, one end of the frame 2 leaves the hook tip 13 and moves into the hook 12 due to the action of gravity. When the distance from the hook tip 13 is greater than the diameter of the rigging, the rigging enters the hook 12 through the hook mouth 16, and the frame 2 is rotated under the gravity of the positioning plate 3, and one end of the frame 2 is re-engaged with the hook tip 13. Then, the hook 1 is in the locked state again.

Further, the frame 2 can be made of various materials such as round steel, steel plate, stainless steel, etc., and can be produced by various processes such as bending, welding, and cutting. As shown in FIG. 3, the frame 2 includes an inner frame 21 and an outer frame 22, the frame 2 is a rectangular closed frame structure, and the frame 2 is bent at a certain angle at the mounting hole 15 of the hook 1 to form the inner frame 21 and the outer frame 21. One end of the frame 22 from the mounting hole 15 to the frame 2 is the inner frame 21 , and the other end from the mounting hole 15 to the frame 2 is the outer frame 22 ; one end of the positioning plate 3 is rotatably connected to the outer frame 22 .

Further, the angle between the inner frame 21 and the outer frame 22 can be changed due to the change of the shape of the hook 1. The angle design principle is: when the hook 1 is in the locked state, the inner frame 21 can be stuck in the hook mouth 16, the outer frame 22 and the hook back 14 just fit together; during the process of the hook 1 changing from the locked state to the open state (the opening of the inner frame 21 and the hook mouth 16 is the largest), the upward movement of the outer frame 22 is related to the lifting of the hook. The hook 1 itself does not interfere. In an embodiment of the present invention, the included angle between the inner frame 21 and the outer frame 22 is 80°-85°, such as 82°, so that when the hook 1 is in the locked state, the inner frame 21 can be locked in the At the hook opening 16, the outer frame 22 and the hook back 14 just fit together; when the hook 1 changes from the locked state to the open state, the upward movement of the outer frame 22 does not interfere with the hook 1 itself.

If the angle between the inner frame 21 and the outer frame 22 is too large, it will not affect the closing of the hook opening 16, but when the anti-decoupling device is opened, the upward movement of the outer frame 22 will interfere with the hook 1 and stop, causing the inner The distance between the frame 21 and the hook tip 13 is too small to be fully opened. When the distance between the inner frame 21 and the hook tip 13 is smaller than the diameter of the rigging, the rigging cannot be taken out from the hook;

If the angle between the inner frame 21 and the outer frame 22 is too small, when the locked state is turned, the outer frame 22 will move downward and hit the hook back 14 and stop, and the inner frame 21 cannot move to the hook tip 13 to get stuck. There is a gap between the inner frame 21 and the hook tip 13. When the gap is larger than the diameter of the rigging, the rigging may slip off from the hook mouth 16, which cannot prevent the hook from disengaging. Therefore, the angle between the inner frame 21 and the outer frame 22 The angle needs to meet the above two conditions to set.

For the hook shape of the hook shown in the drawings, the angle between the inner frame 21 and the outer frame 22 is suitable to be 80°-85°, and about 82° is optimal. Other hook-shaped hooks 1 may satisfy the above two conditions.

The length requirements of the frame 2 are further explained below. Taking FIG. 1 as an example, the outer frame 22 extends from the mounting hole 15 to the hook back 14, and the length of the outer frame 22 is just beyond the hook back 14 (referring to the horizontal direction of the hook back 14). If the length of the outer frame 22 is too short and does not exceed the maximum size in the horizontal direction of the hook back 14, the positioning plate 3 interferes with the hook back 14 and cannot sag naturally; if the length of the outer frame 22 is too long long, the distance between the positioning plate 3 and the hook back 14 is too large when the positioning plate 3 sags naturally, the positioning plate 3 will swing left and right, and when the outer frame 22 is moved upward and opened, the connection between the outer frame 22 and the positioning plate 3 is far from the hook back If it is too far, the positioning plate 3 needs to be lengthened to be stuck on the hook back 14, which is not conducive to the manufacture of the anti-decoupling device.

Further, as shown in FIGS. 4 and 5 , the rotational connection between the middle of the frame and the installation hole is achieved by the following method: the frame 2 is located at the installation hole 15 (the connection between the inner frame 21 and the outer frame 22 ) to set There are two first sleeves 23, the two first sleeves 23 are arranged opposite to each other, one end of the first sleeve 23 is connected to the frame 2, the other end of the first sleeve 23 extends to the inside of the frame 2, the first sleeve 23 The other end is in a floating state.

In an embodiment of the present invention, the mounting hole 15 is connected with a screw, and both ends of the screw are respectively protruded into a first sleeve 23. The first sleeve 23 can rotate relative to the screw, and the frame 2 is connected to the mounting hole 15 through the screw. Rotating connection, in order to make the installation beautiful, the length of the screw entering the first sleeve 23 should not be too long, and the length of the screw entering the first sleeve 23 should be the thickness that can install a nut. The diameter of the first sleeve 23 is larger than the diameter of the screw, and the diameter of the first sleeve 23 is preferably 0.5mm-1mm larger than the diameter of the screw, which can ensure the flexible rotation of the frame 2; if the gap between the first sleeve 23 and the screw is Too large will cause frame 2 to wobble. This arrangement enables the frame 2 to be turned over freely with the first sleeve 23 as the axis, and the anti-decoupling device can be quickly and conveniently installed or replaced by disassembling and assembling screws.

In another embodiment of the present invention, a pin is connected to the mounting hole 15, and both ends of the pin are respectively protruded into a first sleeve 23. The first sleeve 23 can rotate relative to the pin, and the pin makes the The frame 2 is rotatably connected with the mounting hole 15, and the diameter of the first sleeve 23 is larger than the diameter of the pin shaft.

Further, as shown in FIG. 6 , the width L1 of the inner space of the frame 2 (the width of the inner frame 21 and the outer frame 22 ) is greater than the width L2 of the maximum cross-section of the hook 1 to ensure that the frame 2 can pass through the hook tip 13 and insert to the mounting hole 15 on the hook 1.

Further, for the sake of beauty and safety, the connection between the outer frame 22 and the inner frame 21 is an arc structure.

Further, the weight of the outer frame 22 plus the weight of the positioning plate 3 is greater than the weight of the inner frame 21, and the outer frame 22 and the positioning plate 3 play a counterweight role. The hook tip 13 is snapped to ensure that the hook 1 is in a locked state.

Further, the length of the outer frame 22 is greater than the length of the inner frame 21 , and such arrangement can facilitate the operation of the anti-decoupling device.

Further, the length of the inner frame 21 is greater than the length of the distance between the mounting hole 15 and the hook tip 13 , so that the inner frame 21 can only move inward of the hook 12 but not outward.

Further, the material of the positioning plate 3 is various materials such as ordinary steel plate or stainless steel plate.

Further, as shown in FIG. 7 , one end of the positioning plate 3 is provided with a second sleeve 31, and the second sleeve 31 is sleeved on the other end of the frame 2, so that the positioning plate 3 is rotatably connected with the other end of the frame 2, This arrangement enables the positioning plate 3 to be freely turned over. When making the frame 2, the second sleeve 31 is sleeved on the other end of the frame 2, and the second sleeve 31 can also be made into a hoop shape, which is convenient for installation and disassembly.

Further, as shown in FIG. 7 , the other end of the positioning plate 3 is provided with a groove 32, and the groove 32 is an arc structure, so that the groove 32 can be matched with the arc surface of the hook back 14, preventing the positioning plate 3 from being positioned. slips.

Further, it also includes a push-pull hook, through which the positioning plate 3 can be pushed and pulled at a long distance to make the hook 1 in an open or locked state.

During use, when you want to take out the rigging from the hook 1, hold the positioning plate 3 with your hands and lift it up along the outer wall of the hook 1, so that the arc-shaped groove 32 at the other end of the positioning plate 3 runs along the hook back 14. The arc surface slides upward, and at the same time when the positioning plate 3 moves upward, it drives the outer frame 22 to move upward with the screw (the first sleeve 23) as the fulcrum. Due to the lever principle, the inner frame 21 uses the screw (the first sleeve 23) as the The fulcrum moves downward until the hook opening 16 of the hook 1 is fully opened, and the hand is released. At this time, the arc-shaped groove 32 under the positioning plate 3 is close to the hook back 14 of the hook 1, and the gap between the positioning plate 3 and the outer frame 22 It forms a certain acute angle and is self-locking and does not slide down, and the positioning is realized when the hook 1 is in the open state. At this time, the rigging can be taken out from the hook 12, and only one person can use it without the intervention of other people. Remove the rigging with both hands.

After the rigging is taken out, gently pull the positioning plate 3 to the outside of the hook 1 and release it from the hook back 14 of the hook 1. The positioning plate 3 acts as a counterweight and drives the outer frame 22 downward to make a circle with the screw as the fulcrum. Movement, due to the lever principle, one end of the inner frame 21 moves to the hook tip 13. Because the length of the inner frame 21 is greater than the length from the mounting hole 15 to the hook tip 13, when the inner frame 21 is in contact with the hook tip 13, it is stuck. , at this time the hook 1 is in a locked state and is positioned.

When putting in the rigging again, put the rigging directly into the hook port 16, when the rigging is pressed against the inner frame 21, due to the action of gravity, the inner frame 21 makes a circular downward movement with the screw as the fulcrum, and the hook port 16 gradually opens. When the opening degree of the opening 16 is greater than the diameter of the rigging, the rigging enters the hook 1 through the hook opening 16, and the inner frame 21 that loses contact with the rigging is under the action of the gravity of the outer frame 22 and the positioning plate 3, and the outer frame 22 moves downward. , According to the lever principle, one end of the inner frame 21 moves to the hook tip 13 again, and stops after being stuck at the hook tip 13 to prevent the rigging from slipping out of the hook 1 .

From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects:

1. The anti-decoupling device can achieve positioning in both locked and opened states;

2. The movement of the anti-decoupling device from the open to the locked state is realized by the weight of the outer frame 22 and the positioning plate 3;

3. The anti-decoupling device can achieve positioning in the locked state, that is, the inner frame 21 is stuck at the hook 1 mouth and is positioned by the positioning plate 3 to prevent the rigging from decoupling;

4. The anti-decoupling device realizes the process from locking to opening by lifting the positioning plate 3 upward, or it can also be realized by lifting the outer frame 22 upward;

5. The positioning of the anti-decoupling device in the open state is realized by the groove 32 of the positioning plate 3 being stuck on the hook back 14;

6. The anti-decoupling device is suitable for various types of lifting equipment with hook 1, and the external dimensions vary with the size of the hook 1;

7. The frame 2 can be made of various materials such as round steel, steel plate, stainless steel, etc., and can be produced by various processes such as bending, welding, and cutting;

8. The positioning plate 3 can be made of ordinary steel plates, stainless steel plates and other materials;

9. The anti-decoupling device and the mounting hole 15 of the hook 1 can be connected by screws or by pins;

10. The anti-decoupling device can be in two states of opening and locking before being hooked into the rigging;

11. The anti-decoupling device can be positioned after being opened, and can be released without other manual intervention;

12. When the anti-decoupling device is in the open state to take the rigging, it can take the rigging with both hands at the same time;

13. When the hook 1 is far away from the person or cannot be operated close to the person due to environmental reasons, the locking and opening action of the anti-decoupling device can be controlled by pushing and pulling the positioning plate 3 at a long distance by means of a push-pull hook and other tools.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. An anti-unhooking device of a lifting hook, the lifting hook comprises a straight handle and a hook, the hook is provided with a hook tip, one side opposite to the hook tip is a hook back, and the position between the hook tip and the straight handle is a hook opening, the anti-unhooking device is characterized by comprising a frame and a positioning plate, wherein,

the lower end of the straight handle is provided with a mounting hole, the middle part of the frame is rotatably connected with the mounting hole, and one end of the frame is positioned in the hook and can be clamped with the hook tip;

the other end of the frame extends from the mounting hole to the outer side of the hook back, and one end of the positioning plate is rotatably connected with the other end of the frame;

the other end of the positioning plate can be clamped with the hook back by rotating the frame;

when the positioning plate naturally droops, one end of the frame and the hook tip are clamped to the hook opening to be closed, so that the lifting hook is in a locking state;

remove the locating plate can make the frame rotate and make the other end of locating plate with hook back of the body joint, the one end of frame leaves the hook point to remove in the crotch extremely the hook mouth is opened, so that the lifting hook is in the open mode.

2. The unhooking device of a lifting hook according to claim 1,

the frame comprises an inner frame and an outer frame, the frame is of a rectangular structure, the frame is bent at the mounting hole and forms the inner frame and the outer frame, the inner frame is arranged on the frame from the mounting hole to one end of the frame, and the outer frame is arranged on the frame from the mounting hole to the other end of the frame;

one end of the positioning plate is rotatably connected with the outer frame.

3. A hook unhooking prevention device as claimed in claim 2,

be provided with two first sleeves on the frame, two first sleeves set up relatively, first telescopic one end with frame connection, first telescopic other end to the frame inboard extends, the mounting hole is connected with the screw, the both ends of screw all extend to outside the mounting hole, the both ends of screw stretch into one respectively in the first sleeve, first sleeve can be relative the screw rotates.

4. The unhooking device of a lifting hook according to claim 1,

the inner hollow width of the frame is larger than the width of the largest section of the lifting hook.

5. A hook unhooking prevention device as claimed in claim 2,

the connection part of the outer frame and the inner frame is of an arc structure.

6. A hook unhooking prevention device as claimed in claim 2,

the weight of the outer frame plus the weight of the positioning plate is greater than the weight of the inner frame.

7. The unhooking device of a lifting hook according to claim 1,

and a second sleeve is arranged at one end of the positioning plate and sleeved on the other end of the frame, so that the positioning plate is rotatably connected with the other end of the frame.

8. The unhooking device of a lifting hook according to claim 1,

the other end of the positioning plate is provided with a groove, and the groove can be matched with the arc surface of the hook back.

9. A hook unhooking prevention device as claimed in claim 2,

the length of the outer frame is greater than that of the inner frame.

10. The unhooking device of a lifting hook according to claim 1,

the lifting hook is characterized by further comprising a push-pull hook, and the positioning plate can be pushed and pulled remotely through the push-pull hook to enable the lifting hook to be in an open or locked state.

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