CN117243473A - Trigger type compact shelf anti-toppling device - Google Patents

Abstract

The invention relates to the technical field of compact racks, and in particular to a trigger-type compact rack anti-tilting device. The object of the present invention is to provide a safe and reliable trigger-type compact rack anti-tilting device. A trigger-type compact rack anti-tilting device, including a frame body, a first slide rail, a horizontal inclination sensor and a partition. The first slide rail is fixed on the ground. The first slide rail is slidably connected to the frame body. The frame body A horizontal inclination sensor is installed on the top, and partitions are evenly spaced inside the frame, which also includes a balancing mechanism and a supporting mechanism. The lower part of the frame is equipped with a balancing mechanism to prevent the frame from tipping, and there are devices on the left and right sides of the frame to prevent it from falling. Support mechanism for tilting the frame. When the frame tilts forward, the counterweight moves backward to weight the rear part of the frame. When the frame tilts backward, the counterweight moves forward to weight the front part of the frame and is supported on the ground by the poles provided. , safe and reliable, and can effectively prevent the frame from tipping over.

Description

A trigger-type compact rack anti-tilting device

Technical field

The invention relates to the technical field of compact racks, and in particular to a trigger-type compact rack anti-tilting device.

Background technique

Compact racks are mainly used for the storage of files, books and other materials. They usually consist of guide rails laid on the ground, several rows of compact racks, and a drive installed on the outer box of the compact rack to drive the compact racks to move on the above-mentioned guide rails. Mechanism composition: In order to make full use of the space in the archives, the compact racks are generally very high, so the bottom tracks of the compact racks are equipped with devices to prevent them from tipping over.

The patent publication number is CN208160444U, a compact rack anti-tilting device. The invention includes a guide rail. The cross section of the guide rail is C-shaped. A limit strip is provided in the middle of the guide rail. Several-shaped anti-tilting slides are slidingly connected in the guide rail. The protrusions at both ends of the anti-tilting slides are inserted into the guide rail. In the cavities at both ends, a groove body that can accommodate the limit strip is opened in the middle of the bottom of the anti-tilting slide.

The above device uses the guide rails and limiting bars to keep the several-shaped anti-tilting slide in an upright state, thereby preventing the compact rack from falling down. However, since many compact racks are very high, when the compact rack topples over due to force, the anti-tipping slides may easily break, causing the compact rack to topple over. How to design a safe and reliable trigger-type compact rack anti-tipping device is a technical problem that needs to be solved in this patent.

Contents of the invention

In order to overcome the disadvantage that many compact racks are very high, when the compact rack is tipped under force, the anti-tipping slides may easily break, causing the compact rack to topple over. The purpose of the present invention is to provide a safe and reliable trigger-type compact rack. Anti-tip device.

The technical solution is: a trigger-type compact rack anti-tilting device, which includes a frame body, a first slide rail, a horizontal inclination sensor and a partition. The first slide rail is fixed on the ground, and the first slide rail is slidably connected to the rack. There is a horizontal inclination sensor installed on the top of the frame. Partitions are evenly spaced inside the frame. It also includes a balancing mechanism and a supporting mechanism. The lower part of the frame is equipped with a balancing mechanism to prevent the frame from tipping. There are two balance mechanisms on the left and right sides of the frame. A support mechanism is provided to prevent the frame from falling over.

As an improvement to the above solution, the balancing mechanism includes a motor, a threaded rod, a belt, a moving rod and a counterweight. A motor is installed on the front side of the lower part of the frame, and a threaded rod is rotatably connected to the lower part of the frame. The output shafts of the motors are similar to A belt is wound between the threaded rods through a transmission wheel, and a moving rod is threadedly connected to the threaded rods. A counterweight is connected between the moving rods to prevent the frame from tipping. The motor is electrically connected to the horizontal inclination sensor.

As an improvement to the above solution, the support mechanism includes a cylinder, a connecting plate, a support rod and a movable cylinder. Cylinders are installed on the left and right sides of the frame. The cylinder is electrically connected to the horizontal inclination sensor, and the left and right sides of the frame are slidingly connected. There is a connecting plate, which is connected to the telescopic rod of the cylinder. The connecting plates are connected with support rods. The left and right sides of the frame are connected with movable cylinders, and the support rods pass through the movable cylinders.

As an improvement to the above solution, a reinforcement mechanism for fixing the frame on the first slide rail when the frame is tipped is also included. The reinforcement mechanism includes a rod plate, a cross plate, a first return spring, a limit rod and a double head. plate, the left and right sides of the lower part of the frame are connected with limit rods, and the limit rods on the left and right sides are slidingly connected with cross plates. The cross plates are connected to the frame body with first return springs, and the outer sides of the cross plates are A rod-inserting plate is connected, and the left and right parts of the first slide rail are evenly spaced with clamping holes. The rod-inserting plate will move outward and be inserted into the clamping holes of the first slide rail to fix the frame body on the first slide rail. , a double-headed plate is connected to the middle of the counterweight block.

As an improvement to the above solution, both the front and rear parts of the double-headed board are inclined.

As an improvement to the above solution, an anti-deviation mechanism for preventing items on the rack from slipping is also included. The anti-deviation mechanism includes a stop frame, a first connecting rope, a connecting block, a second return spring, a pressure inclined plate, and a bevel edge. The orifice plate and the tie rod are slidably connected to the rack inside the frame. There is a second return spring connected between the bottom of the rack and the frame. The left and right sides of the lower part of the frame are slidingly connected to connecting blocks. The rear parts of the cross plates are connected to each other. There is a pressure inclined plate, and the lower part of the frame body is slidingly connected to a beveled orifice plate. The front side of the beveled orifice plate is in contact with the pressure inclined plate. The rear part of the connecting block is connected to a tie rod. The back side of the beveled orifice plate is in contact with the tie rod and connected. A first connecting rope is connected between the front side of the block and the block frame.

As an improvement to the above solution, an adjustment mechanism for improving the stability of the frame is also included. The adjustment mechanism includes a base, a hole sliding sleeve, a connecting rod, a limit sleeve, a fixed pin and a second slide rail. The left and right sides of the top of the frame are Both sides are connected to bases, and the bases are connected to sliding sleeves with openings. There are connecting rods slidingly connected inside the sliding sleeves with openings. The upper ends of the connecting rods on the left and right sides are slidingly connected with second slide rails. The hole sliding sleeve is slidably connected to the limit sleeve, the limit sleeve is slidably connected to a fixing pin, and the fixing pin is plugged into the hole sliding sleeve.

As an improvement to the above solution, a warning mechanism is also included to serve as a reminder when the frame falls. The warning mechanism includes a sliding plate, a limit frame, a second connecting rope and a third return spring. The left and right sides of the top of the frame are connected The limit frame is slidably connected with a sliding plate, and a second connecting rope is connected between the sliding plate and the adjacent connecting plate. The limit frame is covered with a third return spring, and the third return spring is Both ends are connected with the limiting frame and the sliding plate respectively.

The advantage of the present invention is: when the frame tilts forward, the counterweight moves backward to weight the rear part of the frame; when the frame tilts backward, the counterweight moves forward to weight the front part of the frame, and passes through the set The pole is supported on the ground, which is safe and reliable, and can effectively prevent the frame from tipping; the pole plate is inserted into the hole of the first slide rail to fix the frame on the first slide rail to prevent the frame from tipping; When the rack body topples over, the front side of the rack body is blocked by the stopper to prevent the items on the rack body from sliding down; the second slide rail is moved upward according to the height of the ceiling, and the second slide rail drives the connecting rod to move upward, and the second slide rail is moved upward. The slide rails are fixed on the ceiling above the frame to improve the stability of the frame; the extended sliding plate reminds people approaching to stay away from the frame, so that safety accidents can be avoided.

Description of drawings

Figure 1 is a schematic three-dimensional structural diagram of the present invention.

Figure 2 is a partial three-dimensional structural schematic diagram of the present invention.

Figure 3 is a schematic three-dimensional structural diagram of the balancing mechanism of the present invention.

Figure 4 is a schematic three-dimensional structural diagram of the reinforcement mechanism of the present invention.

Figure 5 is a schematic three-dimensional structural diagram of the support mechanism of the present invention from a first perspective.

Figure 6 is a schematic three-dimensional structural diagram of the support mechanism of the present invention from a second perspective.

Figure 7 is a first three-dimensional structural schematic diagram of the anti-deviation mechanism of the present invention.

Figure 8 is a partial three-dimensional structural schematic diagram of the anti-deviation mechanism of the present invention.

Figure 9 is a schematic diagram of the second three-dimensional structure of the anti-deviation mechanism of the present invention.

Figure 10 is a schematic three-dimensional structural diagram of the adjustment mechanism of the present invention.

Figure 11 is a partial three-dimensional structural diagram of the adjustment mechanism of the present invention.

Figure 12 is a schematic three-dimensional structural diagram of the warning mechanism of the present invention.

Figure 13 is a partial three-dimensional structural diagram of the warning mechanism of the present invention.

Number names in the figure: 1. Frame, 2. First slide rail, 3. Horizontal inclination sensor, 4. Partition plate, 5. Balance mechanism, 51. Motor, 52. Threaded rod, 53. Belt, 54. Moving rod , 55. Counterweight, 6. Reinforcement mechanism, 61. Rod plate, 62. Cross plate, 63. First return spring, 64. Limit rod, 65. Double-headed plate, 7. Support mechanism, 71. Cylinder , 72. Connecting plate, 73. Support rod, 74. Movable cylinder, 8. Anti-deviation mechanism, 81. Bracket, 82. First connecting rope, 83. Connecting block, 84. Second return spring, 85. Pressure Inclined plate, 86, hypotenuse orifice plate, 87, tie rod, 9, adjustment mechanism, 91, base, 92, opening sliding sleeve, 93, connecting rod, 94, limit sleeve, 95, fixed pin, 96, second Slide rail, 10. Warning mechanism, 101. Sliding plate, 102. Limiting frame, 103. Second connecting rope, 104. Third return spring.

Detailed ways

The above solution will be further described below with reference to specific examples. It should be understood that these examples are used to illustrate the present application and are not limited to limiting the scope of the present application. The implementation conditions used in the examples can be further adjusted according to the conditions of specific manufacturers. Unspecified implementation conditions are usually the conditions in routine experiments.

Example 1

A trigger-type compact rack anti-tilting device, with reference to Figures 1, 2, 3, 5 and 6, including a frame body 1, a first slide rail 2, a horizontal inclination sensor 3, a partition 4, and a balancing mechanism 5 and a support mechanism 7, the first slide rail 2 is fixed on the ground, the frame 1 is slidingly connected to the first slide rail 2, a horizontal inclination sensor 3 is installed on the top of the frame 1, and partitions are evenly spaced inside the frame 1 4. There is a balancing mechanism 5 in the lower inner part of the frame 1. The balancing mechanism 5 is used to prevent the frame 1 from tipping. There are support mechanisms 7 on the left and right sides of the frame 1. The support mechanisms 7 are used to prevent the frame 1 from tipping.

Referring to Figure 3, the balancing mechanism 5 includes a motor 51, a threaded rod 52, a belt 53, a moving rod 54 and a counterweight 55. Two motors 51 are installed on the front side of the lower inner part of the frame 1, and the inner lower part of the frame 1 is rotatably connected. There are two threaded rods 52. A belt 53 is wound between the output shaft of the motor 51 and the adjacent threaded rod 52 through a transmission wheel. The two threaded rods 52 are both threadedly connected to a moving rod 54. Between the two moving rods 54 A counterweight 55 is installed between them, and the counterweight 55 is used to prevent the frame 1 from tipping. The motor 51 is electrically connected to the horizontal inclination sensor 3 .

Referring to Figures 5 and 6, the support mechanism 7 includes a cylinder 71, a connecting plate 72, a support rod 73 and a movable cylinder 74. Cylinders 71 are installed on both left and right sides of the frame 1. The cylinder 71 is electrically connected to the horizontal inclination sensor 3. , the left and right sides of the frame 1 are slidingly connected with connecting plates 72, the connecting plates 72 are connected to the telescopic rods of the cylinder 71, the connecting plates 72 are equipped with two struts 73, and the left and right sides of the frame 1 are equipped with movable The cylinder 74, the support rod 73 passes through the movable cylinder 74.

When in use, the first slide rail 2 is fixed to the ground at a designated position, and items are placed on the frame 1. When the frame 1 tilts forward or backward, the horizontal inclination sensor 3 sends a signal to control the output of the motor 51 The shaft drives the threaded rod 52 to rotate forward or reverse through the transmission wheel and the belt 53, and the threaded rod 52 drives the counterweight 55 to move forward or backward through the moving rod 54. In this way, when the frame 1 tilts forward, the counterweight 55 55 moves the rear part of the weighted frame body 1 backward. When the frame body 1 tilts backward, the counterweight block 55 moves forward to weight the front part of the frame body 1, thereby preventing the frame body 1 from tipping. When the frame body 1 becomes stable, it will level The inclination sensor 3 sends a signal, and the output shaft of the control motor 51 drives the threaded rod 52 to rotate forward or reverse through the transmission wheel and the belt 53. The threaded rod 52 drives the counterweight 55 to move forward or backward through the moving rod 54 to reset. When the body 1 falls forward or backward, the horizontal inclination sensor 3 sends a signal to control the telescopic rod of the cylinder 71 to contract. The telescopic rod of the cylinder 71 drives the connecting plate 72 to move downward, and the connecting plate 72 drives the support rod 73 to move downward and support it. On the ground, prevent the frame 1 from tipping. When the frame 1 is stable, the horizontal inclination sensor 3 sends a signal to control the telescopic rod of the cylinder 71 to extend and reset. The telescopic rod of the cylinder 71 drives the support rod 73 to move upward through the connecting plate 72 and reset.

Example 2

On the basis of Embodiment 1, with reference to Figures 1, 2 and 4, a reinforcement mechanism 6 is also included. The reinforcement mechanism 6 includes a rod insertion plate 61, a cross plate 62, a first return spring 63, and a limiting rod 64. and a double-headed plate 65. Two limit rods 64 are welded to the left and right sides of the lower inner part of the frame body 1. Two cross plates 62 are slidingly connected between the two limit rods 64 on the left and right sides. The cross plates 62 There are two first return springs 63 connected to the frame body 1, and rod inserting plates 61 are welded on the outside of the cross plate 62. The left and right parts of the first slide rail 2 are evenly spaced with clamping holes, and the rod inserting plates 61 will It is moved outward and inserted into the card hole of the first slide rail 2. A double-headed plate 65 is installed in the middle of the counterweight block 55. Both the front and rear parts of the double-headed plate 65 are inclined.

When the counterweight 55 moves forward or backward, the double-headed plate 65 is driven to move forward or backward. Both the front and rear parts of the double-headed plate 65 are inclined, so that the double-headed plate 65 contacts the cross plate 62, thereby Pushing the cross plate 62 to move outward, the first return spring 63 is compressed, and the cross plate 62 drives the rod plate 61 to move outward and be inserted into the hole of the first slide rail 2, thereby fixing the frame 1 on the first slide rail 2. on the rail 2 to prevent the frame 1 from falling over. When the counterweight 55 is reset, it drives the double-head plate 65 to reset, and then drives the cross plate 62 to move outward and reset under the reset action of the first return spring 63. The cross plate 62 drives the The rod plate 61 moves outward and resets.

Referring to Figures 1, 2, 7, 8 and 9, an anti-deviation mechanism 8 is also included. The anti-deviation mechanism 8 includes a stop frame 81, a first connecting rope 82, a connecting block 83, a second return spring 84, The pressure inclined plate 85, the hypotenuse orifice plate 86 and the pull rod 87 are slidably connected to the frame body 1 with a retaining frame 81. Four second return springs 84 are connected between the bottom of the retaining frame 81 and the frame body 1. The frame body 1 The left and right sides of the inner lower part are slidably connected with connecting blocks 83, and the rear parts of the two cross plates 62 are welded with pressure inclined plates 85. The inner lower part of the frame body 1 is slidably connected with two beveled edge hole plates 86, with bevel edge holes. The front side of the plate 86 is in contact with the pressure inclined plate 85, the rear side of the connecting block 83 is welded with a tie rod 87, the rear side of the hypotenuse orifice plate 86 is in contact with the tie rod 87, and the front side of the connecting block 83 is connected to the stopper 81 with a third A connecting rope 82.

When the rod inserting plate 61 moves outward, the rod inserting plate 61 drives the pressure inclined plate 85 to move outward, the pressure inclined plate 85 pushes the hypotenuse orifice plate 86 to move backward, and the hypotenuse orifice plate 86 pushes the pull rod 87 toward Move inward, the pull rod 87 drives the connecting block 83 to move inward, the connecting block 83 pulls the blocking frame 81 to move downward through the first connecting rope 82, and the second return spring 84 is compressed. In this way, when the frame body 1 tilts, the blocking frame 81 is The rack 81 blocks the front side of the rack body 1 to prevent the items on the rack body 1 from sliding forward. When the rod inserting plate 61 moves inward and resets, the rod inserting plate 61 drives the pressure inclined plate 85 to move inward and reset, and then in the third The two return springs 84 drive the block frame 81 to move upward and reset under the action of the reset. The block frame 81 pulls the connecting block 83 through the first connecting rope 82 to move outward and reset. The connecting block 83 drives the pull rod 87 to move outward and reset, and the pull rod 87 pushes and tilts. The side hole plate 86 moves forward and resets.

Referring to Figures 1, 2, 10 and 11, an adjustment mechanism 9 is also included. The adjustment mechanism 9 includes a base 91, a hole sliding sleeve 92, a connecting rod 93, a limit sleeve 94, a fixed pin 95 and a second sliding sleeve. rails 96, two bases 91 are installed on the left and right sides of the top of the frame 1, and open sliding sleeves 92 are installed on the bases 91, and connecting rods 93 are slidingly connected inside the opening sliding sleeves 92. The two bases 91 on the left and right sides are The upper ends of the connecting rods 93 are all slidingly connected to second slide rails 96, the opening sliding sleeves 92 are all slidingly connected to the limit sleeves 94, and the limit sleeves 94 are all slidingly connected to fixed pins 95, which are fixed pins 95. Plug into the hole sliding sleeve 92.

Move the fixing pin 95 forward to separate from the hole sliding sleeve 92, and then move the second slide rail 96 upward according to the height of the ceiling. The second slide rail 96 drives the connecting rod 93 to move upward, and the second slide rail 96 can be fixed on the shelf. On the ceiling above the body 1, improve the stability of the frame body 1. After it is fixed, move the reset fixing pin 95 backward so that the fixing pin 95 is inserted into the opening sliding sleeve 92.

Referring to Figures 1, 2, 12 and 13, a warning mechanism 10 is also included. The warning mechanism 10 includes a sliding plate 101, a limiting frame 102, a second connecting rope 103 and a third return spring 104. The top of the frame 1 Limiting frames 102 are installed on both left and right sides, and sliding plates 101 are slidingly connected to the limiting frames 102. Two second connecting ropes 103 are connected between the sliding plates 101 and adjacent connecting plates 72. The limiting frames 102 A third return spring 104 is set on both ends, and both ends of the third return spring 104 are connected to the limiting frame 102 and the sliding plate 101 respectively.

When the connecting plate 72 moves downward, the connecting plate 72 pulls the sliding plate 101 to move outward through the second connecting rope 103, and the third return spring 104 is compressed to remind people approaching to stay away from the frame 1 through the extended sliding plate 101. In this way, safety accidents can be avoided. When the connecting plate 72 moves upward to reset, the second connecting rope 103 is relaxed, and then drives the sliding plate 101 to move inward and reset under the reset action of the third return spring 104 .

The above embodiments are only preferred embodiments of the present invention and are not used to limit the scope of the present invention. Therefore, all equivalent changes made to the content described in the claims of the present invention should be included in the scope of the claims of the present invention. .

Claims (8)

1. The utility model provides a trigger formula compact shelf anti-toppling device, including support body (1), first slide rail (2), level inclination sensor (3) and baffle (4), first slide rail (2) are fixed subaerial, sliding connection has support body (1) on first slide rail (2), horizontal inclination sensor (3) are installed at support body (1) top, inside even interval connection of support body (1) has baffle (4), characterized by, still including balance mechanism (5) and supporting mechanism (7), lower part is equipped with balance mechanism (5) that are used for preventing support body (1) to empty in support body (1), support mechanism (7) that are used for preventing support body (1) to empty are all equipped with in support body (1) left and right sides.

2. The anti-toppling device for the trigger-type compact shelving as claimed in claim 1, wherein the balancing mechanism (5) comprises a motor (51), a threaded rod (52), a belt (53), a moving rod (54) and a balancing weight (55), the motor (51) is installed on the front side of the inner lower portion of the shelf body (1), the threaded rod (52) is rotatably connected to the inner lower portion of the shelf body (1), the belt (53) is wound between the output shaft of the motor (51) and the similar threaded rod (52) through a driving wheel, the moving rod (54) is connected to the threaded rod (52) through uniform threads, the balancing weight (55) for preventing the shelf body (1) from toppling is connected between the moving rods (54), and the motor (51) is electrically connected with the horizontal inclination sensor (3).

3. The anti-toppling device for the trigger-type compact shelf as claimed in claim 2, wherein the supporting mechanism (7) comprises an air cylinder (71), a connecting plate (72), supporting rods (73) and movable cylinders (74), the air cylinder (71) is arranged on the left side and the right side of the shelf body (1), the air cylinder (71) is electrically connected with the horizontal inclination sensor (3), the connecting plate (72) is connected with the left side and the right side of the shelf body (1) in a sliding mode, the connecting plate (72) is connected with telescopic rods of the air cylinder (71), the supporting rods (73) are connected on the connecting plate (72), the movable cylinders (74) are connected on the left side and the right side of the shelf body (1), and the supporting rods (73) penetrate through the movable cylinders (74).

4. The trigger-type compact shelf anti-toppling device according to claim 3, further comprising a reinforcing mechanism (6) for fixing the shelf body (1) on the first sliding rail (2) when the shelf body (1) topples, wherein the reinforcing mechanism (6) comprises a inserted rod plate (61), a cross plate (62), first return springs (63), limiting rods (64) and double-headed plates (65), the limiting rods (64) are connected to the left side and the right side of the lower portion of the shelf body (1), the cross plates (62) are connected between the limiting rods (64) on the left side and the right side in a sliding mode, the first return springs (63) are connected between the cross plates (62) and the shelf body (1), the outer sides of the cross plates (62) are connected with the inserted rod plates (61), the left side and the right side of the first sliding rail (2) are uniformly spaced with clamping holes, the inserted rod plates (61) can move outwards to be inserted into the clamping holes of the first sliding rail (2), the shelf body (1) is fixed on the first sliding rail (2), and the middle portion of the balancing weight (55) is connected with the double-headed plates (65).

5. The tipping prevention device for the trigger type compact shelving as claimed in claim 4, wherein the front and rear parts of the double-headed plate (65) are obliquely arranged.

6. The trigger-type compact shelf anti-toppling device according to claim 5, further comprising an anti-deviation mechanism (8) for preventing objects on the shelf body (1) from slipping, wherein the anti-deviation mechanism (8) comprises a baffle frame (81), a first connecting rope (82), a connecting block (83), a second return spring (84), a pressing inclined plate (85), a bevel edge orifice plate (86) and a pull rod (87), the baffle frame (81) is connected in a sliding manner inside the shelf body (1), a second return spring (84) is connected between the bottom of the baffle frame (81) and the shelf body (1), connecting blocks (83) are connected on the left side and the right side of the inner lower portion of the shelf body (1) in a sliding manner, pressing inclined plates (85) are connected on the rear portion of the cross plate (62), the front side of the bevel edge orifice plate (86) is in contact with the inclined plates (85), pull rods (87) are connected on the rear side of the connecting blocks (83), and the front side of the bevel edge orifice plate (86) is in contact with the pull rods (87), and the front side of the bevel edge orifice plate (83) is connected with the first connecting block (82).

7. The trigger-type compact shelf anti-toppling device according to claim 6, further comprising an adjusting mechanism (9) for improving stability of the shelf body (1), wherein the adjusting mechanism (9) comprises a base (91), an opening sliding sleeve (92), a connecting rod (93), a limiting sleeve (94), a fixing pin (95) and a second sliding rail (96), the base (91) is connected to the left side and the right side of the top of the shelf body (1), the opening sliding sleeve (92) is connected to the base (91) in a sliding mode, the connecting rod (93) is connected to the upper ends of the connecting rods (93) on the left side and the right side in a sliding mode, the second sliding rail (96) is connected to the upper ends of the connecting rods (93) on the left side and the right side in a sliding mode, the limiting sleeve (94) is connected to the fixing pin (95) in a sliding mode, and the fixing pin (95) is inserted into the opening sliding sleeve (92).

8. The trigger-type compact shelf anti-toppling device according to claim 7, further comprising a warning mechanism (10) for reminding when the shelf body (1) topples, wherein the warning mechanism (10) comprises a sliding plate (101), a limiting frame (102), a second connecting rope (103) and a third reset spring (104), the limiting frame (102) is connected to the left side and the right side of the top of the shelf body (1), the sliding plate (101) is connected to the limiting frame (102) in a sliding mode, the second connecting rope (103) is connected between the sliding plate (101) and a similar connecting plate (72), the third reset spring (104) is sleeved on the limiting frame (102), and two ends of the third reset spring (104) are connected with the limiting frame (102) and the sliding plate (101) respectively.