A crane lifting safety limit structure and method

Abstract

The present invention relates to the technical field of crane equipment, and specifically discloses a crane lifting safety limit structure, comprising a crane body, a hook and an anti-fall mechanism, wherein the anti-fall mechanism comprises a base plate, a touch plate, a travel switch, a side frame and a clamping assembly. The base plate is fixedly connected to the crane body and is located below the crane body. The touch plate is sleeved on the outer wall of the base plate. There are multiple travel switches, each of which is respectively arranged below the base plate. There are two side frames, each of which is fixedly connected to the hook and is respectively located on both sides of the hook. There are two clamping assemblies, each of which is respectively arranged above the touch plate. The above structure can clamp the hook even if the crane body loses power, preventing the hook and cargo from falling, reducing the occurrence of safety accidents, and reducing safety hazards during operation.

Description

Technical Field

[0001] The present invention relates to the technical field of crane equipment, and in particular to a crane lifting safety limit structure and method. Background Art

[0002] Currently, cranes can speed up construction efficiency, but they are electrically driven, which results in a fast lifting speed, making it easy for heavy objects to hit the top and cause heavy objects to fall, resulting in safety accidents.

[0003] In the prior art, an effective shock absorption effect is activated by arranging a shock absorbing spring and a shock absorbing plate under the crane, and a limit switch is used to control the electric hoist of the crane. When reaching the top, the contact of the limit switch is touched to stop the electric hoist.

[0004] However, in the prior art, there is a possibility that the electric hoist will be damaged after the cargo hits the top, causing the electric hoist to lose its ability to fix the cargo, which will also cause the cargo to fall and lead to a safety accident. Summary of the Invention

[0005] The purpose of the present invention is to provide a crane lifting safety limit structure and method, which solves the problem in the prior art that the electric hoist may be damaged after the cargo hits the top, causing the electric hoist to lose the ability to fix the cargo, which will also cause the cargo to fall and lead to a safety accident.

[0006] To achieve the above-mentioned purpose, the present invention adopts a lifting safety limit structure of a crane, including a crane body, a hook and an anti-fall mechanism, the anti-fall mechanism including a base plate, a touch plate, a travel switch, a side frame and a clamping assembly, the base plate is fixedly connected to the crane body and is located below the crane body, the touch plate is sleeved on the outer wall of the base plate, there are multiple travel switches, each of which is respectively arranged below the base plate, there are two side frames, and the two side frames are respectively fixedly connected to the hook and are respectively located on both sides of the hook, there are two clamping assemblies, and the two clamping assemblies are respectively arranged above the touch plate.

[0007] In which, the base plate includes a plate body, a sliding tube and a limiting ring. The plate body is fixedly connected to the crane body and is located below the crane body. The sliding tube is fixedly connected to the plate body and is located below the plate body. The limiting ring is fixedly connected to the sliding tube and is sleeved on the outer wall of the sliding tube. The touch plate is sleeved on the outer wall of the sliding tube and is located between the limiting ring and the plate body, and the travel switch is arranged below the plate body.

[0008] Each of the side frames includes a transverse plate and a clamping plate, wherein the transverse plate is fixedly connected to the hook and is located on one side of the hook, and the clamping plate is fixedly connected to the transverse plate and is located above the transverse plate, and the clamping plate has a clamping hole.

[0009] Wherein, each of the side frames further includes an oblique block, one side of the oblique block is fixedly connected to the transverse plate, the other side of the oblique block is fixedly connected to the clamping plate, and the oblique block is located between the transverse plate and the clamping plate.

[0010] Among them, each of the holding components includes an electric cylinder, a limit bin, an adapter bin, a clamping column and a reset spring. The electric cylinder is fixedly connected to the touch plate and is located above the touch plate. The limit bin is fixedly connected to the touch plate and is located above the touch plate. The adapter bin is fixedly connected to the touch plate and is located above the touch plate. The clamping column is arranged inside the limit bin. The reset spring is sleeved on the outer wall of the clamping column and is located inside the limit bin.

[0011] The lifting safety limit structure of the crane further includes an auxiliary mechanism, and there are multiple auxiliary mechanisms, and each of the auxiliary mechanisms is respectively arranged between the plate body and the touch plate.

[0012] Wherein, each of the auxiliary mechanisms includes an auxiliary rod, an auxiliary sleeve, a chuck and a shock-absorbing spring, the auxiliary rod is fixedly connected to the plate body and is located below the plate body, the auxiliary sleeve is fixedly connected to the touch plate and is located above the touch plate, and the auxiliary rod is located inside the auxiliary sleeve, the chuck is fixedly connected to the auxiliary rod and is located at one end of the auxiliary rod, and the chuck is located inside the auxiliary sleeve, the shock-absorbing spring is sleeved on the outer wall of the auxiliary sleeve, and the shock-absorbing spring is located between the plate body and the touch plate.

[0013] Among them, each of the auxiliary mechanisms includes an inner ring and an outer ring, the number of the inner rings is two, each of the inner rings is fixedly connected to the corresponding plate body and the touch plate, and is respectively located inside the shock-absorbing spring, the number of the outer rings is two, each of the outer rings is fixedly connected to the corresponding plate body and the touch plate, and is respectively located on the outer wall of the shock-absorbing spring, and the two ends of the shock-absorbing spring are respectively located between the corresponding inner ring and the outer ring.

[0014] The present invention also provides a method for using a lifting safety limit structure of a crane, comprising the following steps:

[0015] When the goods hit the top, the touch plate is pushed up so that the touch plate contacts the contact of the travel switch;

[0016] After the punch pushes the touch plate to contact the travel switch, the clamping hole is also placed on one side of the clamping column;

[0017] After touching the contact point of the stroke opening, the electric cylinder is rapidly extended and pushes the clamping column to pass through the clamping hole;

[0018] This is used to limit the position of the pallet and prevent the hook from falling, thereby effectively preventing the cargo from falling after hitting the top.

[0019] The lifting safety limit structure and method of a crane of the present invention hangs the cargo on the hook and lifts the hook upward by the crane body, so as to lift the cargo. When the lifting speed of the crane body is too fast or the hook hits the top due to misoperation, the hook pushes the touch plate upward so that the touch plate slides upward on the outer wall of the bottom plate and touches any contact of the travel switch after sliding to a certain distance, thereby activating the clamping assembly to clamp the side frame. When the touch plate touches the travel switch, the side frame must be located on one side of the clamping assembly, and the side frame is clamped and limited by the clamping assembly. With the above structure, the hook can be clamped even when the crane body loses power, thereby preventing the hook and cargo from falling, reducing the occurrence of safety accidents, and reducing safety hazards during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 It is a structural diagram of the first embodiment of the present invention.

[0022] Figure 2 is a side view of the first embodiment of the present invention.

[0023] Figure 3 The present invention Figure 2 AA line structural cross-sectional view.

[0024] Figure 4 is a side view of a second embodiment of the present invention.

[0025] Figure 5 The present invention Figure 4 BB line structural cross-sectional view.

[0026] Figure 6 The present invention Figure 5 A magnified view of the local structure at point C.

[0027] Figure 7 is a side view of a third embodiment of the present invention.

[0028] Figure 8 The present invention Figure 7 DD line structural cross-sectional view.

[0029] Figure 9 The present invention Figure 8 Enlarged view of the local structure at E.

[0030] Figure 10 The present invention is a flowchart of the steps of a method for using a lifting safety limit structure of a crane.

[0031] 101-crane body, 102-hook, 103-touch plate, 104-travel switch, 105-plate, 106-slide tube, 107-limit ring, 108-cross plate, 109-clamping plate, 110-clamping hole, 111-oblique block, 112-electric cylinder, 113-limit bin, 114-adapter bin, 115-clamping column, 116-reset spring, 201-auxiliary rod, 202-auxiliary sleeve, 203-chuck, 204-shock absorber spring, 205-inner ring, 206-outer ring, 301-suction plate, 302-magnetic column, 303-energized coil, 304-magnetic plate. DETAILED DESCRIPTION

[0032] The first embodiment of this application is:

[0033] See also Figures 1 to 3 ,in Figure 1 is a structural diagram of the first embodiment, Figure 2 is a side view of the first embodiment, Figure 3 for Figure 2 The AA line structural cross-sectional view shows a lifting safety limit structure of a crane, comprising a crane body 101, a hook 102 and an anti-fall mechanism, wherein the anti-fall mechanism comprises a base plate, a touch plate 103, a travel switch 104, a side frame and a clamping assembly, wherein the base plate comprises a plate body 105, a sliding tube 106 and a limiting ring 107, the side frame comprises a transverse plate 108, a clamping plate 109 and an inclined block 111, and the clamping assembly comprises an electric cylinder 112, a limiting bin 113, an adapter bin 114, a clamping column 115 and a reset spring 116.

[0034] According to this specific embodiment, the cargo is hung on the hook 102, and the hook 102 is lifted upward by the crane body 101. When the travel switch 104 is touched, the side frame is clamped and fixed by the clamping assembly, thereby clamping the hook 102 after the top is hit.

[0035] The bottom plate is fixedly connected to the crane body 101 and is located below the crane body 101. The touch plate 103 is sleeved on the outer wall of the bottom plate. There are multiple limit switches 104, each of which is respectively arranged below the bottom plate. There are two side frames, which are respectively fixedly connected to the hook 102 and are respectively located on both sides of the hook 102. There are two clamping assemblies, which are respectively arranged above the touch plate 103. The cargo is hung on the hook 102 and at the same time, the cargo is lifted by the crane body 101. The hook 102 is lifted upward to lift the cargo. When the crane body 101 lifts too fast or is misoperated, causing the hook 102 to hit the top, the hook 102 pushes the touch plate 103 upward, so that the touch plate 103 slides upward on the outer wall of the bottom plate, and after sliding to a certain distance, it touches any contact of the travel switch 104 to activate the clamping assembly to clamp the side frame. When the touch plate 103 touches the travel switch 104, the side frame must be located on one side of the clamping assembly, and the side frame is clamped and limited by the clamping assembly.

[0036] Secondly, the plate body 105 is fixedly connected to the crane body 101 and is located below the crane body 101. The slide tube 106 is fixedly connected to the plate body 105 and is located below the plate body 105. The limiting ring 107 is fixedly connected to the slide tube 106 and is sleeved on the outer wall of the slide tube 106. The touch plate 103 is sleeved on the outer wall of the slide tube 106 and is located between the limiting ring 107 and the plate body 105. The travel switch 104 is arranged below the plate body 105, and the slide tube 106 and the travel switch 104 are supported by the plate body 105. At the same time, the limiting ring 107 limits the touch plate 103, and the touch plate 103 is supported by the limiting ring 107 and the ring tube.

[0037] At the same time, the horizontal plate 108 is fixedly connected to the hook 102 and is located on one side of the hook 102. The clamping plate 109 is fixedly connected to the horizontal plate 108 and is located above the horizontal plate 108. The clamping plate 109 has a clamping hole 110. The horizontal plate 108 supports the clamping plate 109. When the hook 102 hits the top, the clamping plate 109 passes through the touch plate 103 and passes through the clamping hole 110 through the clamping assembly, thereby achieving the purpose of fixing the hook 102.

[0038] In addition, one side of the oblique block 111 is fixedly connected to the transverse plate 108, and the other side of the oblique block 111 is fixedly connected to the card plate 109, and the oblique block 111 is located between the transverse plate 108 and the card plate 109. The oblique block 111 can enhance the strength of the card plate 109 and prevent the card plate 109 from deformation.

[0039] Furthermore, the electric cylinder 112 is fixedly connected to the touch plate 103 and is located above the touch plate 103. The limit bin 113 is fixedly connected to the touch plate 103 and is located above the touch plate 103. The adapting bin 114 is fixedly connected to the touch plate 103 and is located above the touch plate 103. The clamping column 115 is arranged inside the limit bin 113. The return spring 116 is sleeved on the outer wall of the clamping column 115 and is located inside the limit bin 113. When the contact of the travel switch 104 is touched, the output end of the electric cylinder 112 is immediately started to extend, and at the same time, the clamping column 115 is pushed, and one end of the clamping column 115 is pushed into the adapting bin 114. The return spring 116 facilitates the rapid reset of the clamping column 115 after the electric cylinder 112 is retracted.

[0040] When using the lifting safety limit structure of a crane of this embodiment, the cargo is hung on the hook 102, and the hook 102 is lifted upward by the crane body 101 to lift the cargo. When the lifting speed of the crane body 101 is too fast or the hook 102 hits the top due to misoperation, the touch plate 103 is pushed upward by the hook 102, so that the touch plate 103 slides upward on the outer wall of the bottom plate, and after sliding to a certain distance, it touches the contact of any one of the travel switches 104 to activate the clamping assembly to clamp the side frame. When the touch plate 103 touches the travel switch 104, the side frame must be located on one side of the clamping assembly, and the side frame is clamped and limited by the clamping assembly. The slide tube 106 and the travel switch 104 are supported by the plate body 105, and the limit ring 107 limits the touch plate 103. The limit ring 107 and the ring tube support the touch plate 103, and the cross plate 108 supports the clamping plate 109. When the hook 102 hits the top, the clamping plate 109 passes through the touch plate 103 and passes through the clamping hole 110 through the clamping assembly, so as to achieve the purpose of fixing the hook 102. The inclined block 111 can enhance the strength of the clamping plate 109 and prevent the clamping plate 109 from deforming. When the clamping assembly is started for clamping, when the contact of the travel switch 104 is touched, the output end of the electric cylinder 112 is immediately started to extend, and at the same time, the clamping column 115 is pushed, and one end of the clamping column 115 is pushed into the adapter compartment 114. The reset spring 116 is convenient for quickly resetting the clamping column 115 after the electric cylinder 112 is retracted, so as to prevent the hook 102 and the cargo from falling, reduce the occurrence of safety accidents, and reduce the safety hazards during operation.

[0041] The second embodiment of this application is:

[0042] Based on the first embodiment, please refer to Figures 4 to 6 ,in Figure 4 is a side view of the second embodiment, Figure 5 for Figure 4 BB line structural cross-sectional view, Figure 6 for Figure 5 An enlarged view of the local structure at point C of the present invention provides a lifting safety limit structure for a crane: it also includes an auxiliary mechanism, and the auxiliary mechanism includes an auxiliary rod 201, an auxiliary sleeve 202, a chuck 203, a shock-absorbing spring 204, an inner ring 205 and an outer ring 206.

[0043] According to this specific embodiment, the auxiliary rod 201 and the auxiliary sleeve 202 are extended and retracted to strengthen the touch panel 103 , thereby increasing the load-bearing capacity of the touch panel 103 .

[0044] The auxiliary rod 201 is fixedly connected to the plate body 105 and is located below the plate body 105. The auxiliary sleeve 202 is fixedly connected to the touch plate 103 and is located above the touch plate 103. The auxiliary rod 201 is located inside the auxiliary sleeve 202. The chuck 203 is fixedly connected to the auxiliary rod 201 and is located at one end of the auxiliary rod 201. The chuck 203 is located inside the auxiliary sleeve 202. The shock-absorbing spring 204 is sleeved on the auxiliary sleeve 202. The outer wall of the auxiliary sleeve 202, and the shock-absorbing spring 204 is located between the plate body 105 and the touch plate 103, the auxiliary rod 201 and the auxiliary sleeve 202 can play a telescopic role, and the auxiliary rod 201 is limited by the chuck 203. The auxiliary rod 201 and the auxiliary sleeve 202 can enhance the load-bearing strength of the touch plate 103. At the same time, the shock-absorbing spring 204 can also play a buffering and shock-absorbing role when the hook 102 hits the top.

[0045] Secondly, there are two inner rings 205, each of which is fixedly connected to the corresponding plate body 105 and the touch plate 103, and is respectively located inside the shock-absorbing spring 204. There are two outer rings 206, each of which is fixedly connected to the corresponding plate body 105 and the touch plate 103, and is respectively located on the outer wall of the shock-absorbing spring 204, and the two ends of the shock-absorbing spring 204 are respectively located between the corresponding inner ring 205 and the outer ring 206. The shock-absorbing spring 204 is limited by the inner ring 205 and the outer ring 206, which can effectively prevent the shock-absorbing spring 204 from being offset at an angle, thereby reducing the shock-absorbing effect of the shock-absorbing spring 204.

[0046] When using the lifting safety limit structure of a crane of this embodiment, the auxiliary rod 201 and the auxiliary sleeve 202 can enhance the load-bearing strength of the touch plate 103. At the same time, the shock-absorbing spring 204 can also play a role of buffering and shock absorption when the hook 102 hits the top. At the same time, the shock-absorbing spring 204 is limited by the inner ring 205 and the outer ring 206, which can effectively prevent the shock-absorbing spring 204 from being offset and reduce the shock-absorbing effect of the shock-absorbing spring 204, thereby effectively buffering the hook 102.

[0047] The third embodiment of this application is:

[0048] Based on the second embodiment, please refer to Figures 7 to 9 ,in Figure 7 is a side view of the third embodiment, Figure 8 for Figure 7 DD line structural cross-sectional view, Figure 9 for Figure 8 An enlarged view of the local structure at E of the crane. The present invention provides a lifting safety limit structure for a crane: it also includes a magnetic attraction mechanism, the magnetic attraction mechanism includes a magnetic attraction component and a suction plate 301, and the magnetic attraction component includes a magnetic column 302, an energized coil 303 and a magnetic plate 304.

[0049] According to this specific embodiment, when the clamping column 115 is pushed by the electric cylinder 112 to contact the adapting compartment 114 , it contacts the magnetic column 302 and is magnetically attracted to each other by electromagnetic force to enhance the stability of the clamping.

[0050] Among them, each of the magnetic suction mechanisms is arranged inside the corresponding holding component, and each of the magnetic suction components is arranged inside the adapter compartment 114. The suction plate 301 is fixedly connected to the clamping column 115 and is located at one end of the clamping column 115. When the clamping column 115 is pushed out by the electric cylinder 112, the clamping column 115 contacts the adapter compartment 114, thereby making the suction plate 301 contact the magnetic suction component, so that the magnetic suction component magnetically attracts the suction plate 301, so that the clamping column 115 is more stable when clamping the clamping plate 109.

[0051] Secondly, the magnetic column 302 is fixedly connected to the adaptation chamber 114 and is located inside the adaptation chamber 114. The energized coil 303 is sleeved on the outer wall of the magnetic column 302 and is located inside the adaptation chamber 114. The magnetic plate 304 is fixedly connected to the magnetic column 302 and is located at one end of the magnetic column 302, and the magnetic plate 304 is located inside the adaptation chamber 114. After the suction plate 301 contacts the magnetic plate 304, the energized coil 303 is immediately energized, and then the energization of the energized coil 303 can make the magnetic column 302 have electromagnetic force. At the same time, the magnetic plate 304 contacts the magnetic column 302, so that the electromagnetic force on the magnetic column 302 is transmitted to the magnetic plate 304, and the suction plate 301 is magnetically reinforced by the magnetic plate 304.

[0052] When the lifting safety limit structure of a crane of this embodiment is used, when the clamping column 115 is pushed out by the electric cylinder 112, the clamping column 115 contacts the adapter bin 114, thereby causing the suction plate 301 to contact the magnetic component, so that the magnetic component magnetically attracts the suction plate 301, making the clamping column 115 more stable when clamping the clamping plate 109. After the suction plate 301 contacts the magnetic plate 304, the energized coil 303 is immediately energized, and the energization of the energized coil 303 can make the magnetic column 302 have electromagnetic force. At the same time, the magnetic plate 304 contacts the magnetic column 302, so that the electromagnetic force on the magnetic column 302 is transmitted to the magnetic plate 304, and the suction plate 301 is magnetically reinforced by the magnetic plate 304.

[0053] See also Figure 10 The present invention also provides a method for using a lifting safety limit structure of a crane, comprising the following steps:

[0054] S1: When the cargo hits the top, the touch plate 103 is pushed up, so that the touch plate 103 contacts the contact of the travel switch 104;

[0055] S2: After the punch pushes the touch plate 103 to contact the travel switch 104, the clamping hole 110 is also placed on one side of the clamping column 115;

[0056] S3: After touching the contact point of the stroke opening, the electric cylinder 112 is rapidly extended, and the clamping column 115 is pushed through the clamping hole 110;

[0057] S4: This is used to limit the position of the card plate 109 and prevent the hook 102 from falling, thereby effectively preventing the cargo from falling after hitting the top.

[0058] In the above steps, when the cargo hits the top, the hook 102 pushes the touch plate 103, so that the touch plate 103 rises to the contact point of the travel switch 104, and at the same time, the electric cylinder 112 is started to push the cylinder at the moment of contact, so that the clamping column 115 clamps the clamping hole 110 in the clamping plate 109, and the clamping column 115 quickly penetrates the clamping hole 110 to limit the clamping plate 109, thereby preventing the cargo from falling after the crane body 101 loses power, thereby effectively protecting the cargo from hitting the top.

[0059] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of the rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A lifting safety limit structure of a crane, comprising a crane body and a hook, wherein the hook is arranged at the lower end of the crane body, characterized in that: It also includes a fall prevention mechanism; The anti-fall mechanism includes a bottom plate, a touch plate, a travel switch, a side frame and a clamping assembly. The bottom plate is fixedly connected to the crane body and is located below the crane body. The touch plate is sleeved on the outer wall of the bottom plate. There are multiple travel switches, each of which is respectively arranged below the bottom plate. There are two side frames, each of which is fixedly connected to the hook and is respectively located on both sides of the hook. There are two clamping assemblies, each of which is respectively arranged above the touch plate. The bottom plate includes a plate body, a sliding tube and a limiting ring. The plate body is fixedly connected to the crane body and is located below the crane body. The sliding tube is fixedly connected to the plate body and is located below the plate body. The limiting ring is fixedly connected to the sliding tube and is sleeved on the outer wall of the sliding tube. The touch plate is sleeved on the outer wall of the sliding tube and is located between the limiting ring and the plate body. The travel switch is arranged below the plate body. Each of the side frames includes a transverse plate and a clamping plate, wherein the transverse plate is fixedly connected to the hook and is located on one side of the hook, and the clamping plate is fixedly connected to the transverse plate and is located above the transverse plate, and the clamping plate has a clamping hole; Each of the clamping components includes an electric cylinder, a limit bin, an adapter bin, a clamping column and a reset spring. The electric cylinder is fixedly connected to the touch plate and is located above the touch plate. The limit bin is fixedly connected to the touch plate and is located above the touch plate. The adapter bin is fixedly connected to the touch plate and is located above the touch plate. The clamping column is arranged inside the limit bin. The reset spring is sleeved on the outer wall of the clamping column and is located inside the limit bin.

2. A crane lifting safety limit structure according to claim 1, characterized in that: Each of the side frames further includes an oblique block, one side of the oblique block is fixedly connected to the transverse plate, the other side of the oblique block is fixedly connected to the clamping plate, and the oblique block is located between the transverse plate and the clamping plate.

3. The lifting safety limit structure of a crane according to claim 2, characterized in that: The lifting safety limit structure of the crane further includes an auxiliary mechanism, and there are multiple auxiliary mechanisms, and each of the auxiliary mechanisms is respectively arranged between the plate body and the touch plate.

4. A crane lifting safety limit structure according to claim 3, characterized in that: Each of the auxiliary mechanisms includes an auxiliary rod, an auxiliary sleeve, a chuck and a shock-absorbing spring. The auxiliary rod is fixedly connected to the plate body and is located below the plate body. The auxiliary sleeve is fixedly connected to the touch plate and is located above the touch plate, and the auxiliary rod is located inside the auxiliary sleeve. The chuck is fixedly connected to the auxiliary rod and is located at one end of the auxiliary rod, and the chuck is located inside the auxiliary sleeve. The shock-absorbing spring is sleeved on the outer wall of the auxiliary sleeve, and the shock-absorbing spring is located between the plate body and the touch plate.

5. The lifting safety limit structure of a crane according to claim 4, characterized in that: Each of the auxiliary mechanisms includes an inner ring and an outer ring, there are two inner rings, each of which is fixedly connected to the corresponding plate body and the touch plate, and is respectively located inside the shock-absorbing spring; there are two outer rings, each of which is fixedly connected to the corresponding plate body and the touch plate, and is respectively located on the outer wall of the shock-absorbing spring, and the two ends of the shock-absorbing spring are respectively located between the corresponding inner ring and the outer ring.

6. A method for using a crane's lifting safety limit structure, using the crane's lifting safety limit structure according to claim 5, characterized in that: The steps include: When the goods hit the top, the touch plate is pushed up so that the touch plate contacts the contact of the travel switch; After the punch pushes the touch plate to contact the travel switch, the clamping hole is also placed on one side of the clamping column; After touching the contact point of the stroke opening, the electric cylinder is rapidly extended and pushes the clamping column to pass through the clamping hole; This is used to limit the position of the pallet and prevent the hook from falling, thereby effectively preventing the cargo from falling after hitting the top.

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