A safety staircase for piers
By designing a safety ladder with a cubic frame structure and using a combination of sliders and elastic blocks as a buffer mechanism, the safety hazards of existing safety ladders breaking are solved, and the structural stability and personnel safety are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 广西新祥高速公路有限公司
- Filing Date
- 2023-12-27
- Publication Date
- 2026-06-30
AI Technical Summary
Existing safety ladders lack cushioning measures in the event of breakage, posing a significant safety hazard and potentially causing injury to workers.
Design a safety ladder for piers, which adopts a cubic frame structure. Through the combination of sliders, elastic blocks and arc blocks, the elasticity of the elastic blocks and the movement of the sliders are used to buffer the ladder breakage. This includes the slider abutting against the bottom of the ladder and the slider abutting against the elastic blocks. When the elastic blocks bend, the deformation of the arc blocks and springs provides buffering.
It improves the stability of the ladder structure, reduces the impact force when it breaks, protects the safety of workers, extends the service life of elastic elements, and provides valuable time for escape.
Smart Images
Figure CN117779624B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of temporary staircase technology, and more specifically to a safety staircase for pier columns. Background Technology
[0002] During bridge construction, temporary ladders are erected on the bridge piers. These temporary ladders are constructed using conventional steel pipe scaffolding, but the need for manual erection at each level increases material and labor costs. Furthermore, due to the height, the overall stability of the temporary ladders is poor, posing significant safety hazards.
[0003] To address the aforementioned issues, Chinese Patent Publication No. CN207728025U discloses a safety ladder for bridge construction, comprising a ladder body and a "Z"-shaped ladder. The ladder body is composed of several individual ladders connected in series from top to bottom via bolt assemblies. Each individual ladder is fixedly connected by uprights, crossbars, and diagonal reinforcing bars to form a steel cubic frame structure. The cubic frame structure is surrounded by a protective mesh fence. Each individual ladder contains a matching "Z"-shaped ladder, which is installed within and connected to the individual ladder. This patent allows for simple, convenient, and quick installation and disassembly, and enables repeated use. It also improves work efficiency, accelerates construction progress, saves resources and costs, achieves standardized manufacturing, and maximizes the safety of operators.
[0004] In actual use, the "Z"-shaped ladder, as described in the patent, consists of three platforms and two ladders connected to the two platforms. The ladders are suspended in mid-air and have no direct support structure. If the ladders suffer significant damage due to prolonged use without the workers' knowledge, they may break when workers walk on them, posing a significant safety hazard. Furthermore, if the ladders break due to external impacts while workers are walking on them, the workers could be directly injured, potentially leading to irreversible consequences. Therefore, this also presents a significant safety risk. Summary of the Invention
[0005] The present invention aims to provide a safety ladder for pier columns to solve the problem that existing safety ladders lack cushioning measures when they break.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: a safety ladder for piers, comprising several cubic frames, each cubic frame including a fence and a "Z"-shaped ladder fixedly connected to the fence, two adjacent fences being detachably connected, the "Z"-shaped ladder including several platforms staggered and fixedly connected to both sides of the fence along the height direction, and a climbing ladder fixedly connected between two adjacent platforms along the height direction of the fence; a support block is provided between two adjacent platforms on the same side of the fence, a fixing block is passed through the support block, and the fixing block is fixedly connected to the support block; a sliding groove is provided laterally on the side wall of the fixing block, and a slider is slidably connected in the sliding groove; vertical grooves are symmetrically provided on the side of the support block near the climbing ladder, vertical blocks are slidably connected in the vertical grooves, and a bendable elastic block is provided between two vertical blocks; one end of the slider abuts against the bottom of the climbing ladder, and the other end of the slider abuts against the elastic block.
[0007] The principle and advantages of this scheme are:
[0008] 1. In this scheme, several cubic frames are stacked vertically, and two adjacent fences are connected to each other, so that several cubic frames can be built and workers can crawl inside them; two adjacent platforms on the same side of the fence are supported by support blocks, which can improve the stability of the structure and make the workers more stable during crawling.
[0009] 2. In this solution, when the ladder breaks, the ladder will squeeze the slider. Since one end of the slider is against the bottom of the ladder, and the other end of the slider is against the elastic block through the arc block, the elasticity of the elastic block itself can buffer the movement of the slider, thereby buffering the breakage of the ladder.
[0010] 3. If the ladder breakage worsens, the ladder will compress the slider to move to the right within the groove. The slider will drive the arc block to move synchronously, causing the arc block to compress the elastic block to move to the right. Furthermore, the elastic block will bend to the right, bringing the two vertical blocks closer together. During the bending process of the arc block, the elasticity of the arc block itself will buffer the movement of the slider, thereby buffering the ladder breakage.
[0011] Furthermore, the width of the elastic block gradually decreases from the two ends of the elastic block to the middle of the elastic block, and the end of the slider away from the ladder abuts against the middle of the elastic block.
[0012] With the above settings, since the width of the elastic block gradually decreases from the two ends of the elastic block to the middle of the elastic block, the middle of the arc block is easier to bend when the arc block squeezes the elastic block, which can guide the bending direction of the elastic block.
[0013] Furthermore, a first arc-shaped block is provided at the end of the slider away from the ladder, and the end of the first arc-shaped block away from the ladder abuts against the middle of the elastic block.
[0014] With the above settings, after the elastic block bends, the arc-shaped block abuts against the bent part of the elastic block, which can solidify the bent elastic block and prevent it from breaking at the bend.
[0015] Furthermore, the support block has a horizontal through hole through which the fixing block passes; both sides of the inner wall of the through hole have vertical guide grooves, and a second arc-shaped block is slidably connected in the guide groove. A first spring is provided between the second arc-shaped block and the guide groove, and the two second arc-shaped blocks abut against each other; a push block is slidably connected in the sliding groove. One end of the push block abuts against the middle of the elastic block, and the other end of the push block has a third arc-shaped block, which abuts against the two second arc-shaped blocks.
[0016] With the above setup, the elastic block bends and pushes the push block to the right, which in turn drives the third arc-shaped block to the right. This causes the third arc-shaped block to simultaneously squeeze the two second arc-shaped blocks, which slide along the path of the guide groove, compressing the first spring. Therefore, the movement of the two second arc-shaped blocks can decompose the force of the third arc-shaped block, and the deformation of the first spring can buffer the movement of the third arc-shaped block, that is, buffer the movement of the push block. Thus, the push block, through the elastic block, arc-shaped block, and slider, plays a buffering role in the breakage of the ladder.
[0017] Furthermore, the pusher block has an arc-shaped groove at one end near the elastic block for abutting against the elastic block after bending.
[0018] With the above configuration, the bent part of the elastic block abuts against the arc groove, which can further solidify the bent elastic block and prevent it from breaking at the bend.
[0019] Furthermore, both sides of the through hole are provided with arc-shaped surfaces for abutting against the elastic block after bending.
[0020] With the above settings, after the elastic block bends, the arc-shaped block abuts against the bent part of the elastic block, and the elastic block also abuts against the arc-shaped surfaces on both sides of the through hole. This can further solidify the bent elastic block and prevent it from breaking at the bend.
[0021] Furthermore, a buffer block is slidably connected inside the slide groove, and a second spring is provided between the buffer block and the slide groove. The buffer block abuts against two second arc-shaped blocks, and the buffer block and the third arc-shaped block are located on both sides of the second arc-shaped blocks.
[0022] With the above setup, the third arc-shaped block continues to move to the right, causing the sidewalls of the second and third arc-shaped blocks to abut against each other; the movement of the third arc-shaped block to the right will compress the buffer block to the right, and compress the second spring; therefore, the deformation of the second spring can buffer the movement of the third arc-shaped block, that is, buffer the movement of the push block. Thus, the push block, through the elastic block, arc-shaped block, and slider, buffers the breakage of the ladder.
[0023] Furthermore, the support block has chambers on both sides of the through hole, with movable blocks slidably connected inside each chamber. A third spring is provided between the movable block and the chamber, and a first wedge is provided on the movable block. A connecting groove is provided between the chamber and the guide groove, and the first wedge is slidably connected to the connecting groove. The second arc-shaped block has a vertical end groove at one end near the chamber, and the first wedge slides in cooperation with the end groove. The end groove is located on the movement trajectory of the first wedge, and a stop groove is provided on the side wall of the first wedge. A transverse groove is provided on the inner wall of the end groove, and a second wedge for being squeezed by the first wedge is slidably connected in the transverse groove. A fourth spring is provided between the second wedge and the transverse groove, and the second wedge is located on the movement trajectory of the first wedge. The second wedge slides in cooperation with the stop groove. It also includes a linkage part that moves the two movable blocks simultaneously with the movement of the buffer block, and the two movable blocks move in opposite directions.
[0024] With the above configuration, during the movement of the buffer block to the right, the buffer block drives the two movable blocks to move closer together through the linkage, and the third spring is compressed. Therefore, the deformation of the third spring can buffer the movement of the buffer block, and in turn buffer the movement of the third arc block, that is, buffer the movement of the push block. Thus, the push block buffers the breakage of the ladder through the elastic block, arc block and slider.
[0025] During the movement of the movable block, the movable block drives the first wedge block to slide in the connecting groove, causing the first wedge block to move towards the end groove; the movable block continues to move, causing the first wedge block to slide into the end groove, and the first wedge block squeezes the second wedge block to slide in the transverse groove, and the fourth spring is compressed; therefore, the deformation of the fourth spring can buffer the movement of the first wedge block and the movable block, and thus buffer the movement of the buffer block, that is, buffer the movement of the third arc block. Therefore, the third arc block buffers the breakage of the ladder through the push block, elastic block, arc block and slider.
[0026] The first wedge pushes the second wedge into the transverse groove. The first wedge continues to move vertically, causing the second wedge to abut against the side wall of the first wedge. The first wedge continues to move, causing the second wedge to face the stop groove. Under the action of the fourth spring, the second wedge slides into the stop groove, thereby positioning the movable block and the second arc-shaped block. In turn, the linkage can position the buffer block. That is, the stability of the ladder breakage buffer is improved by the third arc-shaped block, push block, elastic block, arc-shaped block and slider. Furthermore, the positioning of the buffer block can also protect the second spring, prevent the second spring from being damaged and extend the service life of the second spring.
[0027] Furthermore, the linkage part has linkage arms on both sides of the buffer block and side grooves on both sides of the support block located in the through hole. One end of the linkage arm is hinged to the buffer block, and the other end of the linkage arm passes through the side groove and is hinged to the movable block.
[0028] With the above setup, during the movement of the buffer block to the right, the buffer block drives the movable block to slide in the cavity through the linkage arm, so that the two movable blocks come closer together. Attached Figure Description
[0029] Figure 1 This is a front view of an embodiment of a safety staircase for piers according to the present invention;
[0030] Figure 2 for Figure 1 A sectional view of a single fence in the main view direction;
[0031] Figure 3 for Figure 2 A partial sectional view from the front view direction;
[0032] Figure 4 for Figure 3 Enlarged view of point A in the middle;
[0033] Figure 5 for Figure 4 Enlarged view of section B in the middle. Detailed Implementation
[0034] The following detailed description illustrates the specific implementation method:
[0035] The reference numerals in the accompanying drawings include: fence 10, platform 11, ladder 12, support block 20, vertical groove 21, vertical block 22, elastic block 23, through hole 24, guide groove 25, second arc-shaped block 26, first spring 27, fixing block 30, sliding groove 31, slider 32, first arc-shaped block 33, push block 34, third arc-shaped block 35, arc-shaped groove 36, arc-shaped surface 37, buffer block 38, second spring 39, chamber 40, movable block 41, third spring 42, first wedge 43, connecting groove 44, end groove 45, stop groove 46, transverse groove 47, second wedge 48, fourth spring 49, linkage arm 50, and side groove 51.
[0036] Example
[0037] The basics are as follows: Figure 1 Appendix Figure 2 Appendix Figure 3 Appendix Figure 4 Appendix Figure 5 As shown: A safety staircase for a pier includes several cubic frames. Each cubic frame includes a fence 10 and a "Z"-shaped ladder fixed to the fence 10. Two adjacent fences 10 are connected by existing bolts. The "Z"-shaped ladder includes several platforms 11 that are staggered and fixed to both sides of the fence 10 along the height direction of the fence 10. A ladder 12 is fixed between two adjacent platforms 11 along the height direction of the fence 10.
[0038] A support block 20 is fixedly connected between two adjacent platforms 11 on the same side of the fence 10. A fixing block 30 is installed on the support block 20 and fixedly connected to the support block 20. A sliding groove 31 is opened horizontally on the side wall of the fixing block 30. A slider 32 is slidably connected in the sliding groove 31. The slider 32 is located on the left side of the support block 20. A vertical groove 21 is symmetrically opened on the side of the support block 20 near the ladder 12. A vertical block 22 is slidably connected in the vertical groove 21. A bendable elastic block 23 is fixedly connected between the two vertical blocks 22. The elastic block 23 is an elastic iron block. One end of the slider 32 abuts against the bottom of the ladder 12, and the other end of the slider 32 abuts against the elastic block 23.
[0039] The width of the elastic block 23 gradually decreases from its two ends to its middle, meaning the width is smallest at the middle and largest at both ends. The end of the slider 32 furthest from the ladder 12 abuts against the middle of the elastic block 23. A first arc-shaped block 33 is fixedly connected to the end of the slider 32 furthest from the ladder 12, and the end of the first arc-shaped block 33 furthest from the ladder 12 abuts against the middle of the elastic block.
[0040] A through hole 24 is horizontally opened on the support block 20, and the fixing block 30 passes through the through hole 24 and is fixedly connected to the inner wall of the through hole 24. A guide groove 25 is vertically opened on both sides of the inner wall of the through hole 24. A second arc-shaped block 26 is slidably connected in the guide groove 25. A first spring 27 is fixedly connected between the second arc-shaped block 26 and the guide groove 25. The two second arc-shaped blocks 26 abut against each other. A push block 34 is slidably connected in the sliding groove 31. One end of the push block 34 abuts against the middle of the elastic block 23. A third arc-shaped block 35 is fixedly connected to the other end of the push block 34. The third arc-shaped block 35 abuts against the two second arc-shaped blocks 26.
[0041] The pusher block 34 has an arc-shaped groove 36 at one end near the elastic block 23 for abutting against the elastic block 23 after bending. Both sides of the through hole 24 are provided with arc-shaped surfaces 37 for abutting against the elastic block 23 after bending.
[0042] A buffer block 38 is slidably connected inside the slide groove 31. The buffer block 38 is located on the right side of the support block 20. A second spring 39 is fixed between the buffer block 38 and the slide groove 31. The buffer block 38 abuts against two second arc-shaped blocks 26. The buffer block 38 and the third arc-shaped block 35 are located on both sides of the second arc-shaped blocks 26.
[0043] The support block 20 has chambers 40 on both sides of the through hole 24. A movable block 41 is slidably connected within each chamber 40. A third spring 42 is fixed between the movable block 41 and the chamber 40. A first wedge 43 is fixed to the movable block 41. A connecting groove 44 is formed between the chamber 40 and the guide groove 25. The first wedge 43 is slidably connected to the connecting groove 44. A vertical end groove 45 is formed at the end of the second arc-shaped block 26 near the chamber 40. The first wedge 43 slides into the end groove 45, which is located on the movement trajectory of the first wedge 43. A stop groove 46 is formed on the side wall of the first wedge 43. A transverse groove 47 is formed on the inner wall of the end groove 45. The 7-inch sliding connection is used for the second wedge 48 that is pressed by the first wedge 43. A fourth spring 49 is fixed between the second wedge 48 and the transverse groove 47. The second wedge 48 is located on the movement trajectory of the first wedge 43. The second wedge 48 is slidably engaged with the stop groove 46. The 7-inch sliding connection also includes a linkage part that moves two movable blocks 41 simultaneously with the movement of the buffer block 38. The two movable blocks 41 move in opposite directions. The linkage part is located on the linkage arms 50 on both sides of the buffer block 38 and the side grooves 51 on both sides of the support block 20 located in the through hole 24. One end of the linkage arm 50 is hinged to the buffer block 38, and the other end of the linkage arm 50 passes through the side groove 51 and is hinged to the movable block 41.
[0044] The specific implementation process is as follows:
[0045] In use, several cubic frames are stacked vertically, and adjacent fences 10 are connected by bolts to complete the construction of the cubic frames, allowing workers to crawl inside. Two adjacent platforms 11 on the same side of the fence 10 are supported by support blocks 20, which improves the stability of the structure and makes it more stable for workers to crawl.
[0046] When the ladder 12 breaks, it will compress the slider 32. Since one end of the slider 32 is against the bottom of the ladder 12, and the other end of the slider 32 is against the elastic block 23 through the arc block, the elasticity of the elastic block 23 itself can buffer the movement of the slider 32, thus buffering the breakage of the ladder 12. If the breakage of the ladder 12 is more severe, the ladder 12 compresses the slider 32 and moves it to the right in the slide groove 31. The slider 32 drives the arc block to move synchronously, causing the arc block to compress the elastic block 23 to move to the right. Furthermore, the elastic block 23 bends to the right, and the two vertical blocks 22 move closer together. During the bending process of the arc block, the elasticity of the arc block itself can buffer the movement of the slider 32, thus buffering the breakage of the ladder 12.
[0047] Since the width of the elastic block 23 gradually decreases from the two ends of the elastic block 23 to the middle, the middle of the arc block is easier to bend when the arc block squeezes the elastic block 23. This can guide the bending direction of the elastic block 23, ensuring a buffering effect on the one hand, and ensuring that the elastic block 23 bends and squeezes the push block 34 on the other hand. Furthermore, after the elastic block 23 bends, the arc block abuts against the bent part of the elastic block 23, and the elastic block 23 also abuts against the arc surfaces 37 on both sides of the through hole 24. This can solidify the bent elastic block 23 and prevent the elastic block 23 from breaking at the bend.
[0048] After the elastic block 23 bends, it pushes the push block 34 to move to the right. The push block 34 drives the third arc block 35 to move to the right, so that the third arc block 35 simultaneously squeezes the two second arc blocks 26. The second arc blocks 26 slide along the path of the guide groove 25, and the first spring 27 is compressed. Therefore, the movement of the two second arc blocks 26 can decompose the force of the third arc block 35. Then, the deformation of the first spring 27 can buffer the movement of the third arc block 35, that is, buffer the movement of the push block 34. Therefore, the push block 34 plays a buffering role against the breakage of the ladder 12 through the elastic block 23, the arc block, and the slider 32. In addition, the bent part of the elastic block 23 abuts against the arc groove 36, which can play a solid role in fixing the bent elastic block 23 and prevent the elastic block 23 from breaking at the bend.
[0049] The third arc-shaped block 35 continues to move to the right, causing the second arc-shaped block 26 to abut against the side wall of the third arc-shaped block 35; the movement of the third arc-shaped block 35 to the right will compress the buffer block 38 to move to the right, and compress the second spring 39; therefore, the deformation of the second spring 39 can buffer the movement of the third arc-shaped block 35, that is, buffer the movement of the push block 34. Therefore, the push block 34 buffers the breakage of the ladder 12 through the elastic block 23, the arc-shaped block, and the slider 32.
[0050] During the movement of buffer block 38 to the right, buffer block 38 drives movable block 41 to slide in chamber 40 through linkage arm 50, so that the two movable blocks 41 are close together and the third spring 42 is compressed. Therefore, the deformation of the third spring 42 can buffer the movement of buffer block 38, and thus buffer the movement of third arc block 35, that is, buffer the movement of push block 34. Therefore, push block 34 buffers the breakage of ladder 12 through elastic block 23, arc block and slider 32.
[0051] During the movement of the movable block 41, the movable block 41 drives the first wedge block 43 to slide in the connecting groove 44, causing the first wedge block 43 to move towards the end groove 45; the movable block 41 continues to move, causing the first wedge block 43 to slide into the end groove 45, and the first wedge block 43 squeezes the second wedge block 48 to slide in the transverse groove 47, and the fourth spring 49 is compressed; therefore, the deformation of the fourth spring 49 can buffer the movement of the first wedge block 43 and the movable block 41, and thus buffer the movement of the buffer block 38, that is, buffer the movement of the third arc block 35. Therefore, the third arc block 35 buffers the breakage of the ladder 12 through the push block 34, the elastic block 23, the arc block, and the slider 32.
[0052] The first wedge 43 presses the second wedge 48 into the transverse groove 47. The first wedge 43 continues to move vertically, causing the second wedge 48 to abut against the side wall of the first wedge 43. The first wedge 43 continues to move, causing the second wedge 48 to face the stop groove 46. The second wedge 48 slides into the stop groove 46 under the action of the fourth spring 49. This enables the positioning of the movable block 41 and the second arc-shaped block 26. In turn, the linkage arm 50 can position the buffer block 38. That is, the stability of the breakage buffer of the ladder 12 is improved by the third arc-shaped block 35, the push block 34, the elastic block 23, the arc-shaped block, and the slider 32. Furthermore, the positioning of the buffer block 38 can also protect the second spring 39, prevent the second spring 39 from being damaged, and extend the service life of the second spring 39.
[0053] The cushioning effect of the broken ladder 12 provides temporary protection for the workers climbing it, thus giving them valuable time to escape and ensuring their safety.
[0054] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.
Claims
1. A safety staircase for a pier, comprising several cubic frames, each cubic frame including a fence and a "Z"-shaped ladder fixedly connected to the fence, adjacent fences being detachably connected, the "Z"-shaped ladder including several platforms staggered and fixedly connected to both sides of the fence along the height direction, and a ladder fixedly connected between adjacent platforms along the height direction of the fence; characterized in that: A support block is installed between two adjacent platforms on the same side of the fence. A fixing block passes through the support block and is fixedly connected to the support block. A horizontal groove is provided on the side wall of the fixing block, and a slider is slidably connected in the groove. A vertical groove is symmetrically provided on the side of the support block near the ladder, and a vertical block is slidably connected in the groove. A flexible elastic block is provided between the two vertical blocks. One end of the slider abuts against the bottom of the ladder, and the other end of the slider abuts against the elastic block. The width of the elastic block gradually decreases from the two ends of the elastic block towards the middle. The end of the slider away from the ladder abuts against the elastic block. The middle of the blocks abut against each other; the end of the slider away from the ladder is provided with a first arc-shaped block, and the end of the first arc-shaped block away from the ladder abuts against the middle of the elastic block; the support block is provided with a through hole in the horizontal direction, and the fixing block passes through the through hole; the inner walls on both sides of the through hole are provided with guide grooves in the vertical direction, and a second arc-shaped block is slidably connected in the guide groove. A first spring is provided between the second arc-shaped block and the guide groove, and the two second arc-shaped blocks abut against each other; a push block is slidably connected in the slide groove. One end of the push block abuts against the middle of the elastic block, and the other end of the push block is provided with a third arc-shaped block, which abuts against the two second arc-shaped blocks.
2. The safety ladder for piers according to claim 1, characterized in that: The pusher block has an arc-shaped groove at one end near the elastic block for abutting against the elastic block after it bends.
3. The safety ladder for piers according to claim 2, characterized in that: Both sides of the through hole are provided with arc-shaped surfaces for abutting against the elastic block after bending.
4. The safety ladder for piers according to claim 3, characterized in that: A buffer block is slidably connected inside the slide groove. A second spring is provided between the buffer block and the slide groove. The buffer block abuts against two second arc-shaped blocks. The buffer block and the third arc-shaped block are located on both sides of the second arc-shaped blocks.
5. The safety ladder for piers according to claim 4, characterized in that: The support block has chambers on both sides of the through hole, and movable blocks are slidably connected in the chambers. A third spring is provided between the movable blocks and the chambers, and a first wedge is provided on the movable blocks. A connecting groove is provided between the chambers and the guide groove, and the first wedge is slidably connected to the connecting groove. The second arc-shaped block has a vertical end groove at one end near the chamber, and the first wedge slides in the end groove. The end groove is located on the movement trajectory of the first wedge, and a stop groove is provided on the side wall of the first wedge. A transverse groove is provided on the inner wall of the end groove, and a second wedge is slidably connected in the transverse groove for being squeezed by the first wedge. A fourth spring is provided between the second wedge and the transverse groove. The second wedge is located on the movement trajectory of the first wedge, and the second wedge slides in the stop groove. It also includes a linkage part that moves the two movable blocks simultaneously with the movement of the buffer block, and the two movable blocks move in opposite directions.
6. The safety ladder for piers according to claim 5, characterized in that: The linkage part consists of linkage arms on both sides of the buffer block and side grooves on both sides of the support block located at the through hole. One end of the linkage arm is hinged to the buffer block, and the other end of the linkage arm passes through the side groove and is hinged to the movable block.