A multifunctional bed for student dormitories

Abstract

The present invention relates to a bed, and in particular to a multifunctional bed for student dormitories. It mainly provides a multifunctional bed for student dormitories that is convenient for getting on and off the bed, automatically cleans the used steps, and has a pull-type bed curtain to ensure the sleep quality of students. A multifunctional bed for student dormitories includes: a bed frame, a bed board, a first spring, a telescopic rod, a first limiting rod and a first movable rod. One side of the bed frame is provided with a plurality of steps, the top of the bed frame is slidably provided with a bed board, a plurality of first springs are connected between the bottom of the bed board and the bed frame, one side of the top of the bed frame is symmetrically provided with telescopic rods, the first limiting rods are connected between the telescopic ends of the telescopic rods, and the first movable rods are slidably provided on both sides of the first limiting rod. By driving the first clamping block to no longer clamp the first movable rod, the first movable rod is moved outward by the reset force to form a fence on the front side of the bed frame to prevent the human body from accidentally rolling down.

Description

Technical Field

[0001] The invention relates to a bed, in particular to a multifunctional bed used in a student dormitory. Background Art

[0002] In today's school dormitories for four to six people, the most commonly used new type of beds are those with a bed on top and integrated facilities such as a desk, bookshelf, wardrobe, etc. on the bottom. Each individual has an independent space and does not interfere with each other. There is a controlled staircase between the two beds, which is shared by the two beds and can be used by students to go up and down the stairs.

[0003] Although this facility makes use of the space above and below the dormitory, because the beds are set too high, the force-bearing surface of the controlled stairs is small and inconvenient to clean. After using it, many students reported that it was inconvenient to get on and off the bed. Some students with hand and leg injuries found it even more difficult to climb the high ladder to go to bed. Accidents of students accidentally falling off the bed while sleeping also occurred from time to time. In addition, most beds currently do not have curtains, which cannot create an independent and quiet rest environment for students.

[0004] Therefore, it is necessary to design a multifunctional bed for student dormitories that is convenient for getting on and off the bed, automatically cleans the used steps, and has a pull-type bed curtain to ensure the sleep quality of students. Summary of the invention

[0005] In order to overcome the shortcomings of controlled stairs, such as small foot-stress surface and inconvenient cleaning, inconvenient getting on and off the bed, and the existing beds are not equipped with bed curtains, which affects sleep to a certain extent, the technical problem of the present invention is to provide a multifunctional bed for student dormitories that is convenient for getting on and off the bed, automatically cleans the used steps, and has a pull-type bed curtain to ensure the sleep quality of students.

[0006] The technical implementation scheme of the present invention is: a multifunctional bed for student dormitories, including a bed frame, a bed board, a first spring, a telescopic rod, a first limiting rod, a first movable rod, a second spring, a first clamping block, a rising mechanism and a shielding mechanism, a plurality of steps are provided on one side of the bed frame, a bed board is slidably provided on the top of the bed frame, a plurality of first springs are connected between the bottom of the bed board and the bed frame, a telescopic rod is symmetrically provided on one side of the top of the bed frame, a first limiting rod is connected between the telescopic ends of the telescopic rod, first movable rods are slidably provided on both sides of the first limiting rod, a second spring is connected between the inner side of the first movable rod and the inner wall of the first limiting rod, a first clamping block is provided on the upper part of the bed frame, a rising mechanism is provided on one side of the top of the bed frame, and a shielding mechanism is connected between the upper part of the bed frame.

[0007] Furthermore, the lifting mechanism includes a first fixed block, a second clamping block, a second limiting rod, a third spring, a rack, a gear and a screw rod. A first fixed block is provided on one side of the top of the bed frame, a second clamping block is slidably provided on the upper part of the first fixed block, a second limiting rod is provided on one side of the top of the bed frame, a rack is slidably provided on one side of the second limiting rod, a third spring is connected between the rack and the inner wall of the second limiting rod, a screw rod is rotatably provided on the middle side of the top of the bed frame, and a gear is provided at the bottom of the screw rod.

[0008] Furthermore, the shielding mechanism includes a support frame, a bed curtain, a spiral spring, a gear ring, a third clamping block, a torsion spring and a pull rope. The support frames are symmetrically arranged on the upper part of the bed frame, and a rotating shaft is rotatably connected between the upper parts of the support frames. A spiral spring is connected to the support frames on both sides of the rotating shaft, a bed curtain is wound on the rotating shaft, a gear ring is rotatably arranged on the rotating shaft, a third clamping block is rotatably arranged on one side of the rotating shaft, a torsion spring is connected between the third clamping block and the rotating shaft, and a pull rope is wound on the gear ring.

[0009] Furthermore, it also includes a snap mechanism, which includes a second fixed block, a fourth spring, a second movable block and a second movable rod. The second fixed block is provided on the upper part of the bed frame, and a second movable block is slidably provided on the top of the second fixed block. The bottom of the second movable block is connected to the second fixed block with a fourth spring, and a second movable rod is slidably provided on one side of the top of the bed frame.

[0010] Furthermore, it also includes a cleaning mechanism, which includes a fixed plate, a third movable rod, a fifth spring and a sixth spring. The fixed plate is connected between the steps, and a third movable rod is slidably provided on one side of the fixed plate. The fifth spring is connected between the third movable rod and the upper part of the fixed plate, and the sixth spring is connected between the third movable rod and the lower part of the fixed plate.

[0011] Furthermore, it also includes a storage mechanism, which includes a fixed frame, a first movable block and a material receiving plate. The upper part of the bed frame is connected to the fixed frame, and the lower inner wall of the fixed frame is hinged with multiple first movable blocks through elastic parts, and the material receiving plate is hinged between the first movable blocks.

[0012] Furthermore, it also includes a door closing mechanism, which includes a fourth movable rod, a seventh spring, a movable plate, an eighth spring and a third limiting rod. The fourth movable rod is rotatably provided on the upper part of the fixed plate, the seventh spring is connected between the fourth movable rod and the fixed plate, a movable plate is slidably provided in the middle part of the fixed plate, the third limiting rod is symmetrically provided on one side of the fixed plate, the limiting plates are slidably connected between the third limiting rods, and the eighth spring is connected between the bottom of the limiting plates and the third limiting rods.

[0013] Furthermore, a plurality of brushes are provided at the bottom of the third movable rod.

[0014] The beneficial effects are as follows: 1. By driving the first clamping block to no longer clamp the first movable rod, the first movable rod is moved outward by the reset force to form a fence on the front side of the bed frame to prevent the human body from accidentally rolling down;

[0015] 2. Pull the rope downwards, and the third block will lock the gear ring to drive the shaft and the bed curtain to be pulled out, providing a darker environment for the user to rest and promote sleep;

[0016] 3. When the bed board moves downward due to the weight of the human body, the third movable rod will no longer be stuck. The third movable rod moves to the right, driving the brush to move to the right, thereby achieving the purpose of cleaning the steps;

[0017] 4. By setting up an item storage slot, the items that the user needs on a daily basis can be placed. By rotating the fourth movable rod, the movable plate is driven to move downward to block the item storage slot to ensure its privacy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0019] Figure 2 It is a schematic diagram of the three-dimensional structure of the mechanism of the present invention.

[0020] Figure 3 It is a schematic diagram of the three-dimensional structure of the opening mechanism of the present invention.

[0021] Figure 4 It is a schematic diagram of the three-dimensional structure of the first part of the lifting mechanism of the present invention.

[0022] Figure 5 It is a schematic diagram of the three-dimensional structure of the second part of the lifting mechanism of the present invention.

[0023] Figure 6 It is a schematic diagram of the three-dimensional structure of the first part of the shielding mechanism of the present invention.

[0024] Figure 7 It is a schematic diagram of the three-dimensional structure of the second part of the shielding mechanism of the present invention.

[0025] Figure 8 It is a schematic diagram of the three-dimensional structure of the first part of the storage mechanism of the present invention.

[0026] Fig. 9 It is a schematic diagram of the three-dimensional structure of the second part of the storage mechanism of the present invention.

[0027] Fig.10 It is a schematic diagram of the three-dimensional structure of the buckle mechanism of the present invention.

[0028] Fig.11 It is a schematic diagram of the three-dimensional structure of the cleaning mechanism of the present invention.

[0029] Fig.12 It is a schematic diagram of the three-dimensional structure of the door closing mechanism of the present invention.

[0030] Parts names and serial numbers in the figure: 1_bed frame, 2_bed board, 3_first spring, 40_telescopic rod, 41_first limit rod, 42_first movable rod, 43_second spring, 44_first block, 5_rising mechanism, 50_first fixed block, 51_second block, 52_second limit rod, 53_third spring, 54_rack, 55_gear, 56_screw rod, 6_shielding mechanism, 60_support frame, 61_bed curtain, 62_volute spring, 63_gear ring, 64_third block, 65_torsion spring, 66_pull rope, 7_storage mechanism, 70_fixed frame, 71_first movable block, 72_material receiving plate, 8_buckle mechanism, 80_second fixed block, 81_fourth spring, 82_second movable block, 83_second movable rod, 9_cleaning mechanism, 90_fixed plate, 91_third movable rod, 92_fifth spring, 93_sixth spring, 10_door closing mechanism, 1000_fourth movable rod, 1001_seventh spring, 1002_movable plate, 1003_eighth spring, 1004_third limiting rod. DETAILED DESCRIPTION

[0031] The preferred technical solutions of the present invention are described in detail below with reference to the accompanying drawings. Example 1

[0032] A multifunctional bed for student dormitories, such as Figures 1 to 7 As shown, it includes a bed frame 1, a bed board 2, a first spring 3, a telescopic rod 40, a first limiting rod 41, a first movable rod 42, a second spring 43, a first clamping block 44, a rising mechanism 5 and a shielding mechanism 6. Four steps are provided on the right side of the bed frame 1. A bed board 2 is slidably provided on the top of the bed frame 1. Four first springs 3 are connected between the bottom of the bed board 2 and the bed frame 1. Telescopic rods 40 are symmetrically provided on the left and right sides of the top front of the bed frame 1. A first limiting rod 41 is connected between the telescopic ends of the telescopic rod 40. First movable rods 42 are slidably provided on the left and right sides of the first limiting rod 41. Second springs 43 are connected between the inner sides of the first movable rods 42 and the inner walls of the first limiting rod 41. A first clamping block 44 is provided in the middle of the upper front side of the bed frame 1. A rising mechanism 5 is provided on the top front side of the bed frame 1. A shielding mechanism 6 is connected between the upper front sides of the bed frame 1.

[0033] The lifting mechanism 5 includes a first fixed block 50, a second clamping block 51, a second limiting rod 52, a third spring 53, a rack 54, a gear 55 and a screw rod 56. A first fixed block 50 is provided on the right front side of the top of the bed frame 1. A second clamping block 51 is slidably provided on the upper part of the first fixed block 50. A second limiting rod 52 is provided on the right front side of the top of the bed frame 1. A rack 54 is slidably provided on the left side of the second limiting rod 52. A third spring 53 is connected between the right side of the rack 54 and the inner wall of the second limiting rod 52. A screw rod 56 is rotatably provided on the middle side of the top of the bed frame 1. The screw rod 56 is threadedly connected to the first limiting rod 41. A gear 55 is provided at the lower part of the screw rod 56, and the gear 55 cooperates with the rack 54.

[0034] The shielding mechanism 6 includes a support frame 60, a bed curtain 61, a spiral spring 62, a gear ring 63, a third clamping block 64, a torsion spring 65 and a pull rope 66. The support frame 60 is symmetrically arranged on the left and right sides of the upper front side of the bed frame 1, and a rotating shaft is rotatably connected between the upper parts of the support frame 60. The left and right sides of the rotating shaft are connected to the support frame 60 with a spiral spring 62. The bed curtain 61 is wound on the rotating shaft. The right part of the rotating shaft is rotatably provided with a gear ring 63, and the right side of the rotating shaft is rotatably provided with a third clamping block 64. A torsion spring 65 is connected between the third clamping block 64 and the rotating shaft, and a pull rope 66 is wound around the gear ring 63.

[0035] In the initial state, the second block 51 is stuck on the rack 54, the third spring 53 is compressed, the first movable rod 42 is stuck on the first block 44, the second spring 43 is compressed, the user can step on the steps to enter the upper bunk, and after lying down, the bed board 2 is forced to move downward, driving the first spring 3 to be compressed, and the second block 51 is manually pushed to move upward and no longer stuck on the rack 54. The third spring 53 is reset to drive the rack 54 to move to the left and contact the gear 55. The gear 55 rotates through the screw rod 56 to drive the first limit rod 41 and the above components to move upward. The first movable rod 42 moves upward and no longer contacts the first clamping block 44. The second spring 43 returns to its original position and drives the first movable rod 42 to move outward to form a fence on the front side of the bed frame 1 to prevent the human body from rolling down. When the user needs to take a rest, the pull rope 66 is pulled downward to drive the gear ring 63 to rotate and cooperate with the third clamping block 64. The third clamping block 64 is clamped by the force of the torsion spring 65. The gear ring 63 rotates through the third clamping block 64 to drive the rotating shaft and the bed curtain 61 to rotate and be pulled out. The volute spring 62 is deformed. After the adjustment is completed, the pull rope 66 is pulled out. 6 is hooked on the right support frame 60 to fix the state of the bed curtain 61. After use, the drawstring 66 is taken out and no longer hooked on the right support frame 60. Then the drawstring 66 is stopped, and the scroll spring 62 is reset to drive the bed curtain 61 to rotate and retract through the rotating shaft. At the same time, the gear ring 63 is no longer subjected to force and stops operating. The rotation of the rotating shaft drives the third clamping block 64 to rotate and contact the gear ring 63. The rotation of the third clamping block 64 drives the torsion spring 65 to deform. When the bed curtain 61 is rolled up and stops rotating, the third clamping block 64 is no longer subjected to force, and the torsion spring 65 is reset. The third clamping block 64 is driven to rotate and re-engage the gear ring 63, and then the pull rope 66 can be manually recovered. After getting out of bed, it is necessary to manually push the first movable rod 42 to move inward to compress the second spring 43, and then squeeze the first limit rod 41 to move downward to drive the first movable rod 42 to engage in the first clamping block 44. The first limit rod 41 moves downward to drive the screw rod 56 to reverse, thereby driving the rack 54 to move outward through the gear 55. The third spring 53 is compressed, pushing the second clamping block 51 to move downward to engage the rack 54. Example 2

[0036] On the basis of Example 1, Figure 1 , Fig.10and Fig.11 As shown, a buckle mechanism 8 is also included, and the buckle mechanism 8 includes a second fixed block 80, a fourth spring 81, a second movable block 82 and a second movable rod 83. A second fixed block 80 is provided on the right rear side of the upper part of the bed frame 1, and a second movable block 82 is slidably provided on the top of the second fixed block 80. The bottom of the second movable block 82 is connected to the second fixed block 80 with a fourth spring 81, and a second movable rod 83 is slidably provided on the right rear side of the top of the bed frame 1.

[0037] It also includes a cleaning mechanism 9, which includes a fixed plate 90, a third movable rod 91, a fifth spring 92 and a sixth spring 93. The fixed plate 90 is connected between the right sides of the steps, an item placement groove is opened on the right side of the lower part of the fixed plate 90, a third movable rod 91 is slidably provided on the left side of the fixed plate 90, a plurality of brushes are provided at the bottom of the third movable rod 91, a fifth spring 92 is connected between the third movable rod 91 and the left side of the upper part of the fixed plate 90, and a sixth spring 93 is connected between the third movable rod 91 and the left side of the lower part of the fixed plate 90.

[0038] In the initial state, the second movable block 82 is against the third movable rod 91, and the fifth spring 92 and the sixth spring 93 are both stretched. The bed board 2 moves downward and squeezes the second movable rod 83 to move downward, thereby squeezing the second movable block 82 downward and no longer against the third movable rod 91. The fourth spring 81 is compressed. At the same time, the fifth spring 92 and the sixth spring 93 are reset to drive the third movable rod 91 to move right, so that the brush can be driven to move right to clean the steps. After cleaning, when the operator gets off the bed and no longer squeezes the second movable rod 83, the fourth spring 81 is reset to drive the second movable block 82 to move upward, thereby squeezing the second movable rod 83 to move upward and reset, and then pushes the third movable rod 91 to move leftward for reset. The third movable rod 91 moves leftward and contacts the second movable block 82, and the second movable block 82 moves downward. When the third movable rod 91 moves and resets and is located on the left side of the second movable block 82, the second movable block 82 is driven upward by the action of the fourth spring 81 to jam the third movable rod 91. At this time, the fifth spring 92 and the sixth spring 93 are both stretched. Example 3

[0039] On the basis of Example 2, Figure 1 , Figure 8 , Fig. 9 and Fig.12 As shown, a storage mechanism 7 is also included, which includes a fixed frame 70, a first movable block 71 and a material receiving plate 72. The fixed frame 70 is connected to the front side of the upper part of the bed frame 1. Four first movable blocks 71 are hinged on the inner wall of the lower part of the fixed frame 70 through elastic parts, and the material receiving plates 72 are hinged between the first movable blocks 71.

[0040] It also includes a door closing mechanism 10, which includes a fourth movable rod 1000, a seventh spring 1001, a movable plate 1002, an eighth spring 1003 and a third limiting rod 1004. A fourth movable rod 1000 is rotatably provided on the upper rear side of the fixed plate 90, and a seventh spring 1001 is connected between the fourth movable rod 1000 and the fixed plate 90. A movable plate 1002 is slidably provided on the right side of the middle of the fixed plate 90, and a third limiting rod 1004 is symmetrically provided on the front and back right side of the fixed plate 90. A limiting plate is slidably connected between the third limiting rods 1004, and the limiting plate is connected to the movable plate 1002 for limiting, and an eighth spring 1003 is connected between the bottom of the plate and the third limiting rod 1004.

[0041] The user can place items such as a water cup in the fixing frame 70, the material receiving plate 72 is forced to move downward, driving the first movable block 71 to rotate, and the elastic member is deformed. When the water cup is taken out, the elastic member is reset and the material receiving plate 72 is driven to move upward and reset through the first movable block 71; in the initial state, the fourth movable rod 1000 is against the limit plate, the movable plate 1002 is located above the item placement slot, and the eighth spring 1003 is stretched, so that the user can place idle items such as books in the item placement slot, and when it is time to go to bed and rest, the rotation The fourth movable rod 1000 no longer presses against the limit plate, the seventh spring 1001 is deformed, and the eighth spring 1003 is reset to drive the movable plate 1002 to move downward through the limit plate to block the item placement slot to prevent items from being lost. When the movable plate 1002 needs to be opened again, the limit plate is manually pushed to drive the movable plate 1002 to move upward, the eighth spring 1003 is stretched, and then the push of the fourth movable rod 1000 is stopped. The seventh spring 1001 is reset to drive the fourth movable rod 1000 to rotate and reset against the limit plate.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A multifunctional bed for student dormitories, characterized in that it includes: The invention comprises: a bed frame (1), a bed board (2), a first spring (3), a telescopic rod (40), a first limit rod (41), a first movable rod (42), a second spring (43), a first clamping block (44), a rising mechanism (5) and a shielding mechanism (6); four steps are provided on one side of the bed frame (1); a bed board (2) is provided on the top of the bed frame (1) in a sliding manner; four first springs (3) are connected between the bottom of the bed board (2) and the bed frame (1); telescopic rods (40) are symmetrically provided on one side of the top of the bed frame (1); the telescopic rods (40) are provided on one side of the top of the bed frame (1); A first limiting rod (41) is connected between the telescopic ends of the bed frame (40), first movable rods (42) are slidably provided on both sides of the first limiting rod (41), second springs (43) are connected between the inner sides of the first movable rods (42) and the inner walls of the first limiting rods (41), a first clamping block (44) is provided on the upper part of the bed frame (1), a lifting mechanism (5) is provided on one side of the top of the bed frame (1), and a shielding mechanism (6) is connected between the upper parts of the bed frame (1), so as to provide a relatively dim environment for the user to rest and promote sleep; The lifting mechanism (5) comprises: a first fixed block (50), a second clamping block (51), a second limiting rod (52), a third spring (53), a rack (54), a gear (55) and a screw rod (56); a first fixed block (50) is provided on one side of the top of the bed frame (1); a second clamping block (51) is slidably provided on the upper part of the first fixed block (50); a second limiting rod (52) is provided on one side of the top of the bed frame (1); a rack (54) is slidably provided on one side of the second limiting rod (52); a third spring (53) is connected between the rack (54) and the inner wall of the second limiting rod (52); a screw rod (56) is rotatably provided on the middle side of the top of the bed frame (1); the screw rod (56) is threadedly connected to the first limiting rod (41); a gear (55) is provided on the lower part of the screw rod (56); the gear (55) cooperates with the rack (54); The shielding mechanism (6) comprises: a support frame (60), a bed curtain (61), a scroll spring (62), a gear ring (63), a third clamping block (64), a torsion spring (65) and a pull rope (66); the support frame (60) is symmetrically arranged on the upper part of the bed frame (1); a rotating shaft is rotatably connected between the upper part of the support frame (60); scroll springs (62) are connected between the support frame (60) and both sides of the rotating shaft; a bed curtain (61) is wound on the rotating shaft; a gear ring (63) is rotatably arranged on the rotating shaft; a third clamping block (64) is rotatably arranged on one side of the rotating shaft; a torsion spring (65) is connected between the third clamping block (64) and the rotating shaft; and a pull rope (66) is wound on the gear ring (63); The bed frame (1) further comprises a buckle mechanism (8), the buckle mechanism (8) comprising: a second fixed block (80), a fourth spring (81), a second movable block (82) and a second movable rod (83); the second fixed block (80) is provided on the upper part of the bed frame (1); the second movable block (82) is slidably provided on the top of the second fixed block (80); the fourth spring (81) is connected between the bottom of the second movable block (82) and the second fixed block (80); and the second movable rod (83) is slidably provided on one side of the top of the bed frame (1); The cleaning mechanism (9) also includes: a fixed plate (90), a third movable rod (91), a fifth spring (92) and a sixth spring (93); the fixed plate (90) is connected between the steps; an article placement slot is provided at the lower portion of the fixed plate (90); a third movable rod (91) is slidably provided at one side of the fixed plate (90); a fifth spring (92) is connected between the third movable rod (91) and the upper portion of the fixed plate (90); and a sixth spring (93) is connected between the third movable rod (91) and the lower portion of the fixed plate (90); A plurality of brushes are provided at the bottom of the third movable rod (91); In the initial state, the second movable block (82) abuts against the third movable rod (91), the fifth spring (92) and the sixth spring (93) are both stretched, the bed board (2) moves downward, squeezing the second movable rod (83) downward, thereby squeezing the second movable block (82) downward and no longer abutting against the third movable rod (91), the fourth spring (81) is compressed, and at the same time the fifth spring (92) and the sixth spring (93) are reset to drive the third movable rod (91) to move rightward, thereby driving the brush to move rightward to clean the steps, and after cleaning is completed, when the operator gets off the bed and no longer squeezes the second movable rod (83), the fourth spring (81) is compressed. The spring (81) resets and drives the second movable block (82) to move upward, thereby squeezing the second movable rod (83) to move upward and reset, and then pushing the third movable rod (91) to move leftward to reset. The third movable rod (91) moves leftward to contact the second movable block (82), and the second movable block (82) moves downward. When the third movable rod (91) moves and resets and is located on the left side of the second movable block (82), the second movable block (82) is driven by the fourth spring (81) to move upward and can clamp the third movable rod (91). At this time, the fifth spring (92) and the sixth spring (93) are both stretched.

2. A multifunctional bed for student dormitories according to claim 1, characterized in that: The bed frame (1) also includes a storage mechanism (7), which includes a fixed frame (70), a first movable block (71) and a material receiving plate (72). The upper part of the bed frame (1) is connected to the fixed frame (70), and the inner wall of the lower part of the fixed frame (70) is hinged with four first movable blocks (71) through elastic members, and the material receiving plates (72) are hinged between the first movable blocks (71).

3. A multifunctional bed for student dormitories according to claim 2, characterized in that: The invention also comprises a door closing mechanism (10), wherein the door closing mechanism (10) comprises: a fourth movable rod (1000), a seventh spring (1001), a movable plate (1002), an eighth spring (1003) and a third limiting rod (1004); the fourth movable rod (1000) is rotatably provided on the upper part of the fixed plate (90); the seventh spring (1001) is connected between the fourth movable rod (1000) and the fixed plate (90); the movable plate (1002) is slidably provided in the middle part of the fixed plate (90); the third limiting rod (1004) is symmetrically provided on one side of the fixed plate (90); the limiting plates are slidably connected between the third limiting rods (1004); the limiting plates are connected to the movable plate (1002); and the eighth spring (1003) is connected between the bottom of the limiting plates and the third limiting rod (1004).

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