Mechanical anti-falling fence for climbing operation

Abstract

The invention relates to the technical field of mechanical anti-falling fences, in particular to a mechanical anti-falling fence for climbing operation, which comprises a displacement mechanism, a lifting assembly is mounted at the top of the displacement mechanism, and a windproof gravity center adjusting mechanism is mounted at the top of the lifting assembly. The operation window is located on the leeward face, the cover body can resist wind and sand, a comfortable and safe working environment is provided for workers, and during operation, the balancing weight slides at the bottom of the cover body according to the magnitude of wind power, gravity distribution adjustment is automatically conducted, so that the cover body is not prone to toppling, the wind power is continuously increased, and the lantern ring and the first magnet move towards the operation window; a plurality of guardrails are formed at the position of the operation window, the risk that workers and goods fall off is reduced, the sealing plate moves to relieve sealing of the force unloading air opening, the force unloading air opening and the operation window are communicated, part of wind can penetrate through the force unloading air opening, wind force borne by the cover body is reduced, and the side inclination risk is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical anti-fall fences, in particular to a mechanical anti-fall fence for high-altitude operations. Background Art

[0002] Flexible support refers to a prestressed structural system formed with cables as the main load-bearing components. It is mainly composed of foundation, steel structure, steel strands, connecting accessories, wind-resistant system and other parts. Its structural methods are diverse, including single-layer suspension cable system, prestressed double-layer cable system, prestressed cable net, hybrid system, chord-supported dome, transverse reinforcement and other structures. After the steel strands are erected, the load-bearing objects are installed on their foundation.

[0003] During the installation of the load, since the working height is higher than the height of the workers, it is necessary to use climbing machinery. In order to ensure safety, a mechanical anti-fall fence will be installed on the outside of the workbench to reduce the possibility of workers and goods falling from heights. The fences are mostly hollow steel structures and do not have a windproof effect. When working in a specific environment, such as the installation of solar panels, they are mostly located in open areas, where winds blow frequently and strongly, and may be accompanied by dust and gravel, affecting the normal operation of the workers. The existing technology can solve the above problems by adding wind shields, but the addition of wind shields will increase the wind force on the climbing machinery, increase the risk of rollover, and reduce the safety factor. Summary of the invention

[0004] In response to the above-mentioned problems, the present application provides a mechanical anti-fall fence for high-altitude operations, which solves the problem that the mechanical anti-fall fences in the prior art are mostly hollow steel structures and do not have a windproof effect. When operating in a specific environment, such as the installation of solar panels, they are mostly located in open areas, where winds blow frequently and strongly, and may be accompanied by dust and gravel, affecting the normal operation of workers. The prior art can solve the above-mentioned problems by adding wind shields, but the addition of wind shields will increase the wind force on the high-altitude operation machinery, increase the risk of rollover, and reduce the safety factor.

[0005] The technical solution of the present invention is: A mechanical anti-fall fence for high-altitude operations, comprising a displacement mechanism, a lifting assembly is installed on the top of the displacement mechanism, a center of gravity adjustment mechanism for wind protection is installed on the top of the lifting assembly, an emergency protection mechanism for avoiding danger in strong winds is installed outside the center of gravity adjustment mechanism, the center of gravity adjustment mechanism comprises a cover body, a plurality of wind plates rotating according to wind force are installed on the top of the cover body, and a counterweight block that slides in position according to the number of rotations of the wind plates is installed at the bottom of the cover body; An operation window for construction is provided on one side of the cover body, and an emergency force unloading vent is provided on the other side of the cover body; The emergency protection mechanism includes two symmetrically installed sealing plates for sealing the unloading air vents. A ring is slidably installed on the outer periphery of the sealing plate, and multiple lever plates are hinged on the outer side of the ring. When the wind is strong, the sealing plate slides into the ring to release the seal on the unloading air vent and drive the lever plate to rotate and open. Driven by the wind, the two rings merge at the operating window to form an emergency guardrail.

[0006] Furthermore, a steering unit is fixedly mounted on the bottom of the cover body, and the bottom of the steering unit is fixedly mounted on the top of the lifting assembly.

[0007] Furthermore, an assembly bin is fixedly installed on the top of the cover body, and a wind direction detection unit is fixedly installed on the top of the assembly bin; A rotating shaft is rotatably installed in the middle of the assembly bin, and wind plates are evenly and fixedly installed on the outside of the rotating shaft. Two interconnected leverage vents are arranged in a position deviating from the middle of the assembly bin.

[0008] Furthermore, a coil spring is fixedly installed on the outside of the rotating shaft, and the outer end of the coil spring is fixedly installed on the inside of the assembly bin. Partitions are movably installed on the top and bottom of the coil spring, and the partitions are fixedly installed on the inside of the assembly bin. The partitions are rotatably connected with the rotating shaft.

[0009] Furthermore, a linkage rope is wound around the outer side of the rotating shaft near the bottom, the linkage rope is slidably connected with the assembly bin, and a plurality of pulleys are fixedly installed on the outer side of the cover body, and the pulleys are movably connected with the linkage rope; An installation groove is provided at the bottom of the cover body, and the counterweight block is slidably installed in the installation groove. The end of the counterweight block is fixedly connected with a linkage rope, and the linkage rope is slidably penetrated and connected with the cover body.

[0010] Furthermore, two first limit rods are fixedly installed on the inner side of the installation groove, the first limit rods are slidably connected with the counterweight block, and a first return spring is fixedly installed on the counterweight block and the inner side of the installation groove, and the first return spring is movably sleeved on the outer periphery of the first limit rods.

[0011] Furthermore, a second magnet is fixedly mounted on the end of the sealing plate, a guide rail is slidably engaged on the inner side of the collar, the guide rail is fixedly mounted on the periphery of the cover body, and a first magnet is fixedly mounted on the end of the collar; A sliding groove is provided on the inner side of the sleeve ring, and the sealing plate is slidably installed inside the sliding groove. An elastic member is fixedly installed between the end of the sealing plate and the inner side of the sliding groove.

[0012] Furthermore, a limiting groove connected to the mounting groove is provided at the bottom inner side of the cover body, a linkage rod is slidably installed in the middle of the limiting groove, and a plurality of separation plates are evenly fixedly installed on the outer side of the linkage rod, and the separation plates are provided with pointed ends.

[0013] Furthermore, a second limiting rod is slidably installed in the middle of the linkage rod, a second return spring is fixedly installed between the linkage rod and the inner side of the cover body, and the second return spring is movably installed on the outer periphery of the second limiting rod.

[0014] The beneficial effects of the present invention are as follows: The mechanical anti-fall fence for high-altitude operation described in the present invention is provided with a cover body, an operation window is opened on the outer side of the cover body, and the operation window is located on the leeward side. The cover body can resist wind and sand, and provide a more comfortable and safe working environment for workers. During operation, the counterweight slides at the bottom of the cover according to the wind force, automatically adjusting the gravity distribution so that the cover is not easy to tip over; As the wind force continues to increase, the two second magnets and the sealing plate separate, and the sealing plate enters the collar, squeezing and rubbing the cylindrical part of the lever plate to make it open outward, thereby increasing the force-bearing area and angle of the collar. Under the action of wind force, the collar and the first magnet move toward the operating window, forming multiple guardrails at the operating window to reduce the risk of workers and goods falling. The sealing plate moves to release the seal on the unloading vent, allowing the unloading vent and the operating window to be connected, allowing some wind to pass through, reducing the wind force on the cover and reducing the risk of rollover. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0016] Figure 1 A schematic diagram of the overall structure of a mechanical anti-fall fence for high-altitude operations provided by the present invention; Figure 2 A schematic diagram of the partial structure of a mechanical anti-fall fence for high-altitude operations provided by the present invention; Figure 3 A schematic diagram of the cover structure of a mechanical anti-fall fence for high-altitude operations provided by the present invention; Figure 4 A schematic diagram of the assembly compartment structure of a mechanical anti-fall fence for high-altitude operations provided by the present invention; Figure 5 A schematic diagram of the internal structure of an assembly compartment of a mechanical anti-fall fence for high-altitude operations provided by the present invention; Figure 6 A schematic diagram of the internal structure of a cover body of a mechanical anti-fall fence for high-altitude operations provided by the present invention; Figure 7 for Figure 6 A magnified image of point A; Figure 8 A schematic diagram of the internal structure of a collar of a mechanical anti-fall fence for high-altitude operations provided by the present invention; Fig. 9 for Figure 8 The enlarged view of point B; Fig.10 A schematic diagram of the structure of a lever plate of a mechanical anti-fall fence for high-altitude operations provided by the present invention; Fig.11 A schematic diagram of the guide rail structure of a mechanical anti-fall fence for high-altitude operations provided by the present invention.

[0017] In the figure: 1. Displacement mechanism; 2. Lifting components; 3. Center of gravity adjustment mechanism; 31. Cover body; 32. Assembly chamber; 33. Wind direction detection unit; 34. Leverage air outlet; 35. Wind plate; 36. Coil spring; 37. Rotating shaft; 38. Linkage rope; 39. Pulley; 310. Counterweight; 311. First limit rod; 312. First return spring; 313. Mounting slot; 314. Steering unit; 315. Working window; 4. Emergency protection mechanism; 41. Linkage rod; 42. Limiting slot; 43. Second limiting rod; 44. Second return spring; 45. Separation plate; 46. Unloading vent; 47. Guide rail; 48. Ring; 49. Sealing plate; 410. Lever plate; 411. Elastic member; 412. First magnet; 413. Second magnet; 414. Slide groove. DETAILED DESCRIPTION

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structure of the drawings is only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0019] As shown in Figure 1- Fig.11 As shown, an embodiment of the present invention provides a mechanical anti-fall fence for high-altitude operations, including a displacement mechanism 1, a lifting assembly 2 is installed on the top of the displacement mechanism 1, a center of gravity adjustment mechanism 3 for wind protection is installed on the top of the lifting assembly 2, an emergency protection mechanism 4 for avoiding danger in strong winds is installed on the outer side of the center of gravity adjustment mechanism 3, and the center of gravity adjustment mechanism 3 includes a cover body 31, a plurality of wind plates 35 rotating according to wind force are installed on the top of the cover body 31, and a counterweight block 310 that slides according to the number of rotations of the wind plates 35 is installed at the bottom of the cover body 31, thereby reducing the possibility of the cover body 31 tipping over and improving the safety of the operation; An operation window 315 for construction is provided through one side of the cover body 31, and an emergency force unloading vent 46 is provided through the other side of the cover body 31; The emergency protection mechanism 4 includes two symmetrically installed sealing plates 49 for sealing the unloading vents 46. A collar 48 is slidably installed on the periphery of the sealing plate 49. A plurality of lever plates 410 are hinged on the outer side of the collar 48. When the wind is strong, the sealing plate 49 slides into the collar 48 to release the seal on the unloading vents 46 and drive the lever plates 410 to rotate and open. Driven by the wind, the two collars 48 merge at the operating window 315 to form an emergency guardrail.

[0020] In this embodiment, the sealing plate 49 moves to release the seal of the unloading vent 46, so that the unloading vent 46 and the operation window 315 are connected, and part of the wind can pass through, thereby reducing the wind force on the cover body 31 and reducing the risk of rollover. At the same time, the lifting assembly 2 descends and resets, lowering the cover body 31, and the staff moves away from it as quickly as possible and enters a safe area.

[0021] Specifically, a steering unit 314 is fixedly installed at the bottom of the cover body 31 for fine-tuning the direction of the cover body 31 , and the bottom of the steering unit 314 is fixedly installed on the top of the lifting assembly 2 .

[0022] Specifically, an assembly chamber 32 is fixedly installed on the top of the cover body 31, and a wind direction detection unit 33 is fixedly installed on the top of the assembly chamber 32 for detecting the wind direction.

[0023] In this embodiment, the wind direction detection unit 33 is used to detect the wind direction. The staff adjusts the direction of the displacement mechanism 1 according to the wind direction so that the working window 315 is on the leeward side. The steering unit 314 can assist in fine-tuning the cover body 31. The staff and construction parts enter the cover body 31, and the lifting assembly 2 rises. The cover body 31 can resist wind and sand, providing a more comfortable and safe working environment for the staff.

[0024] Specifically, a rotating shaft 37 is rotatably installed in the middle of the assembly bin 32, and the wind plates 35 are evenly fixedly installed on the outside of the rotating shaft 37. The assembly bin 32 is provided with two interconnected leverage vents 34 deviating from the middle position for wind circulation to drive the wind plates 35 to rotate.

[0025] In this embodiment, during operation, wind passes through the wind port 34 to drive the wind plate 35 and the rotating shaft 37 to rotate.

[0026] Specifically, a coil spring 36 is fixedly installed on the outside of the rotating shaft 37. It stores energy when the wind is strong and releases energy when the wind is weak, driving the rotating shaft 37 to rotate in the opposite direction. The outer end of the coil spring 36 is fixedly installed on the inside of the assembly bin 32. Partitions are movably installed on the top and bottom of the coil spring 36. The partitions are fixedly installed on the inside of the assembly bin 32, and the partitions are rotatably connected with the rotating shaft 37.

[0027] Specifically, a linkage rope 38 is wound around the outer side of the rotating shaft 37 near the bottom, and the linkage rope 38 is slidably connected with the assembly chamber 32. A plurality of pulleys 39 are fixedly installed on the outer side of the cover body 31 to reduce the friction resistance of the linkage rope 38, so that the linkage rope 38 slides more sensitively, and the pulley 39 is movably connected with the linkage rope 38. A mounting groove 313 is provided at the bottom of the cover body 31, and the counterweight block 310 is slidably installed in the mounting groove 313. The end of the counterweight block 310 is fixedly connected to the linkage rope 38, and the linkage rope 38 is slidably connected to the cover body 31. Balls can be rolled and embedded in the mounting groove 313 to reduce the sliding resistance between the mounting groove 313 and the counterweight block 310. Other existing technologies can also be used to achieve this effect. These are relatively mature existing technologies and are not listed one by one in this article.

[0028] In this embodiment, the rotating shaft 37 rotates, the coil spring 36 accumulates force, the rotating shaft 37 rotates and reels the linkage rope 38, thereby pulling the counterweight block 310 close to the windward side of the cover body 31, so that the cover body 31 is not easy to topple over under strong winds.

[0029] Specifically, two first limit rods 311 are fixedly installed on the inner side of the installation groove 313, which are used to limit the sliding trajectory of the counterweight block 310. The first limit rod 311 is slidably connected with the counterweight block 310. The counterweight block 310 and the inner side of the installation groove 313 are fixedly installed with a first return spring 312, which is used to return the counterweight block 310. The first return spring 312 is movably mounted on the outer side of the first limit rod 311.

[0030] In this embodiment, when the wind weakens, the coil spring 36 releases energy, releases the linkage rope 38, and the counterweight block 310 moves in the opposite direction under the elastic force of the first return spring 312, automatically adjusting the gravity distribution so that the cover body 31 is not easy to tip over.

[0031] Specifically, the second magnet 413 is fixedly installed at the end of the sealing plate 49, the guide rail 47 is slidably engaged with the inner side of the collar 48, the guide rail 47 is fixedly installed on the outer periphery of the cover body 31, and the first magnet 412 is fixedly installed at the end of the collar 48; A slide groove 414 is provided on the inner side of the ring 48 , and the sealing plate 49 is slidably installed inside the slide groove 414 . An elastic member 411 is fixedly installed between the end of the sealing plate 49 and the inner side of the slide groove 414 . When the two second magnets 413 are separated, the elastic member 411 drives the sealing plate 49 to enter the ring 48 .

[0032] Specifically, a limiting groove 42 connected to the installation groove 313 is provided at the bottom inner side of the cover body 31, a linkage rod 41 is slidably installed in the middle of the limiting groove 42, the limiting groove 42 is used to limit the moving trajectory of the linkage rod 41, and a plurality of separation plates 45 are evenly fixedly installed on the outer side of the linkage rod 41, and the separation plates 45 are provided with a pointed end to facilitate the separation of the second magnet 413.

[0033] In this embodiment, the wind force continues to increase, the counterweight block 310 slides and squeezes the linkage rod 41, thereby pushing the separation plate 45 through the unloading vent 46, squeezing the connection between the two second magnets 413, so that the two second magnets 413 and the sealing plate 49 are separated, and under the pulling force of the elastic member 411, the sealing plate 49 enters the collar 48, squeezes and rubs the cylindrical part of the lever plate 410, so that it opens outward, that is, increases the force area and angle of the collar 48, and under the action of wind force, the collar 48 and the first magnet 412 move toward the operating window 315, and finally the two first magnets 412 fit and adsorb to form multiple guardrails at the operating window 315, reducing the risk of staff and goods falling, and the sealing plate 49 moves to release the seal of the unloading vent 46, so that the unloading vent 46 and the operating window 315 are connected, and part of the wind can pass through, reducing the wind force on the cover body 31 and reducing the risk of rollover.

[0034] Specifically, a second limiting rod 43 is slidably installed in the middle of the linkage rod 41 to limit the movement trajectory of the linkage rod 41. A second return spring 44 is fixedly installed between the linkage rod 41 and the inner side of the cover body 31 to drive the separation plate 45 to reset. The second return spring 44 is movably installed on the periphery of the second limiting rod 43.

[0035] How it works: The wind direction detection unit 33 is used to detect the wind direction. The staff adjusts the direction of the displacement mechanism 1 according to the wind direction so that the working window 315 is on the leeward side. The steering unit 314 can assist in fine-tuning the cover body 31. The staff and construction parts enter the cover body 31, and the lifting assembly 2 rises. The cover body 31 can resist wind and sand, providing a more comfortable and safe working environment for the staff.

[0036] During operation, wind passes through the leveraged vent 34, blowing the wind plate 35 and the rotating shaft 37 to rotate, the coil spring 36 accumulates force, the rotating shaft 37 rotates and reels in the linkage rope 38, and then pulls the counterweight 310 close to the windward side of the cover body 31, so that the cover body 31 is not easily tipped over by strong winds. When the wind weakens, the coil spring 36 releases energy, releases the linkage rope 38, and the counterweight 310 moves in the opposite direction under the elastic force of the first return spring 312, and automatically performs gravity distribution adjustment, so that the cover body 31 is not easily tipped over.

[0037] As the wind force continues to increase, the counterweight 310 slides and squeezes the linkage rod 41, thereby pushing the separation plate 45 through the unloading vent 46, squeezing the connection between the two second magnets 413, so that the two second magnets 413 and the sealing plate 49 are separated. Under the pulling force of the elastic member 411, the sealing plate 49 enters the collar 48, squeezes and rubs the cylindrical part of the lever plate 410, so that it opens outward, that is, the force-bearing area and angle of the collar 48 are increased. Under the action of the wind force, the collar 48 and the first magnet 412 move toward the operating window 315, and finally the two first magnets 412 fit and adsorb to form multiple guardrails at the operating window 315, reducing the risk of workers and goods falling. The sealing plate 49 moves to release the seal of the unloading vent 46, so that the unloading vent 46 and the operating window 315 are connected, and part of the wind can pass through, thereby reducing the wind force on the cover body 31 and reducing the risk of rollover. At the same time, the lifting assembly 2 descends and resets, lowering the cover body 31, and the staff separates the first magnet 412 and moves away as quickly as possible to enter the safe area.

[0038] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A mechanical anti-fall fence for high-altitude operations, comprising a displacement mechanism (1), a lifting assembly (2) being mounted on the top of the displacement mechanism (1), a center of gravity adjustment mechanism (3) for wind protection being mounted on the top of the lifting assembly (2), and an emergency protection mechanism (4) for avoiding danger in strong winds being mounted on the outer side of the center of gravity adjustment mechanism (3), characterized in that: The center of gravity adjustment mechanism (3) comprises a cover body (31), a plurality of wind plates (35) rotating according to wind force are mounted on the top of the cover body (31), and a counterweight block (310) sliding in position according to the number of rotations of the wind plates (35) is mounted on the bottom of the cover body (31); An operation window (315) for construction is provided through one side of the cover body (31), and an emergency force unloading vent (46) is provided through the other side of the cover body (31); The emergency protection mechanism (4) comprises two symmetrically mounted sealing plates (49) for sealing the force unloading vents (46); a collar (48) is slidably mounted on the periphery of the sealing plate (49); a plurality of lever plates (410) are hingedly connected to the outer side of the collar (48); when the wind force is strong, the sealing plate (49) slides into the collar (48), releases the seal on the force unloading vents (46), and drives the lever plates (410) to rotate and open; driven by the wind force, the two collars (48) merge at the operation window (315) to form an emergency guardrail.

2. A mechanical anti-fall fence for high-altitude operations as claimed in claim 1, characterized in that: A steering unit (314) is fixedly mounted on the bottom of the cover body (31), and the bottom of the steering unit (314) is fixedly mounted on the top of the lifting assembly (2).

3. The mechanical anti-fall fence for high-altitude operations according to claim 1, characterized in that: An assembly bin (32) is fixedly mounted on the top of the cover body (31), and a wind direction detection unit (33) is fixedly mounted on the top of the assembly bin (32); A rotating shaft (37) is rotatably mounted in the middle of the assembly bin (32), and the wind plates (35) are evenly and fixedly mounted on the outside of the rotating shaft (37). Two communicating force-assisted air vents (34) are provided through the assembly bin (32) at a position deviating from the middle.

4. A mechanical anti-fall fence for high-altitude operations as claimed in claim 3, characterized in that: A coil spring (36) is fixedly mounted on the outside of the rotating shaft (37), and an outer end of the coil spring (36) is fixedly mounted on the inside of the assembly bin (32). A partition is movably mounted on the top and bottom of the coil spring (36), and the partition is fixedly mounted on the inside of the assembly bin (32). The partition is rotatably connected to the rotating shaft (37).

5. A mechanical anti-fall fence for high-altitude operations as claimed in claim 4, characterized in that: A linkage rope (38) is wound around the outer side of the rotating shaft (37) near the bottom, the linkage rope (38) is slidably connected to the assembly bin (32), and a plurality of pulleys (39) are fixedly mounted on the outer side of the cover body (31), and the pulleys (39) are movably connected to the linkage rope (38); A mounting groove (313) is provided at the bottom of the cover body (31), and the counterweight block (310) is slidably mounted in the mounting groove (313). The end of the counterweight block (310) is fixedly connected to a linkage rope (38), and the linkage rope (38) is slidably penetrated and connected to the cover body (31).

6. A mechanical anti-fall fence for high-altitude operations as claimed in claim 5, characterized in that: Two first limit rods (311) are fixedly installed inside the installation groove (313), the first limit rods (311) are slidably connected with the counterweight block (310), a first return spring (312) is fixedly installed inside the counterweight block (310) and the installation groove (313), and the first return spring (312) is movably sleeved on the outer periphery of the first limit rods (311).

7. The mechanical anti-fall fence for high-altitude operations according to claim 1, characterized in that: A second magnet (413) is fixedly mounted on the end of the sealing plate (49); a guide rail (47) is slidably engaged on the inner side of the collar (48); the guide rail (47) is fixedly mounted on the periphery of the cover body (31); and a first magnet (412) is fixedly mounted on the end of the collar (48); A slide groove (414) is provided on the inner side of the sleeve ring (48), and the sealing plate (49) is slidably mounted inside the slide groove (414). An elastic member (411) is fixedly mounted between the end of the sealing plate (49) and the inner side of the slide groove (414).

8. The mechanical anti-fall fence for high-altitude operations as claimed in claim 5, characterized in that: The inner bottom of the cover body (31) is provided with a limit slot (42) connected to the mounting slot (313); a linkage rod (41) is slidably mounted in the middle of the limit slot (42); a plurality of separation plates (45) are evenly fixedly mounted on the outer side of the linkage rod (41); and the separation plates (45) are provided with a pointed end.

9. A mechanical anti-fall fence for high-altitude operations as claimed in claim 8, characterized in that: A second limiting rod (43) is slidably installed in the middle of the linkage rod (41), a second return spring (44) is fixedly installed between the linkage rod (41) and the inner side of the cover body (31), and the second return spring (44) is movably installed on the outer periphery of the second limiting rod (43).

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