Base station antenna recycling and separating equipment

Abstract

The utility model belongs to the technical field of base station antenna recycling and separating, and provides base station antenna recycling and separating equipment which comprises a base, a positioning device and a separating device. A first hydraulic machine is arranged at the upper end of the base, a first telescopic rod is movably connected to the upper end of the first hydraulic machine, and a discharging table is fixedly connected to the upper end of the first telescopic rod; a first support and a second support are arranged on two sides of the base, a positioning device is arranged at the upper end of the first support, a supporting plate is arranged at the upper end of the second support, a third support is arranged at the upper end of the supporting plate, and a separating device is arranged at the upper end of the third support. According to the utility model, through the cooperation of the positioning device and the separating device, the reflecting plate and the outer cover of the base station antenna are separated, rapid fatigue caused by long-time manual separation of the outer cover and the reflecting plate of the base station antenna is avoided, time and labor are saved, meanwhile, the separated outer cover and the reflecting plate are not located at the same place, and time cost increase caused by mixing of the outer cover and the reflecting plate is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of base station antenna recovery and separation, in particular to a base station antenna recovery and separation device. Background Art

[0002] As the name implies, the base station antenna is the antenna configured on the base station. It is usually composed of an outer cover, a reflector at one end of the outer cover, a vibrator on the reflector, and a feed network (except for 5G base stations). Its function is to convert the base station electrical signal into an electromagnetic wave signal and send it to the terminal, and receive the electromagnetic wave signal sent by the terminal and convert it into an electrical signal and send it to the base station for decoding to obtain information. During the use of the base station antenna, it will be damaged due to various natural or man-made factors, and a new base station antenna needs to be replaced, and the replaced base station antenna needs to be recycled and reused.

[0003] In the prior art, base station antennas are usually recovered and separated manually. During the recovery and separation process, the base station antenna needs to be disassembled first, and the reflector is manually pulled out from one end of the base station antenna cover (at this time, there is no bracket connected to the base station antenna cover), and then the components on the reflector are disassembled and recovered. Base station antennas are generally large in size and heavy in weight. The step of manually pulling out the reflector from one end of the base station antenna repeatedly will cause the operator to quickly fatigue and is time-consuming and laborious. At the same time, the removed cover and reflector will be mixed together, increasing the time cost.

[0004] In summary, the utility model therefore provides a base station antenna recovery and separation device. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides a base station antenna recovery and separation device to solve the problem that the base station antenna is usually recovered and separated manually in the prior art. During the recovery and separation process, the base station antenna needs to be disassembled first, and the reflector is manually pulled out from one end of the base station antenna cover (at this time, there is no bracket connected to it on the base station antenna cover), and then the components on the reflector are disassembled and recovered. The base station antenna is generally large in size and heavy in weight. The step of manually pulling out the reflector from one end of the base station antenna repeatedly will cause the operator to quickly fatigue, which is time-consuming and laborious. At the same time, the removed cover and reflector will be mixed together, increasing the time cost and other problems.

[0006] A base station antenna recovery and separation device comprises a base, a positioning device and a separation device, a No. 1 hydraulic press is arranged on the upper end of the base, a No. 1 telescopic rod is movably connected to the upper end of the No. 1 hydraulic press, a material discharge table is fixedly connected to the upper end of the No. 1 telescopic rod, a No. 1 bracket and a No. 2 bracket are arranged on both sides of the base, a positioning device is arranged on the upper end of the No. 1 bracket, a support plate is arranged on the upper end of the No. 2 bracket, a No. 3 bracket is arranged on the upper end of the support plate, and a separation device is arranged on the upper end of the No. 3 bracket.

[0007] Preferably, the positioning device includes a No. 1 shell, a No. 2 hydraulic press is arranged inside the No. 1 shell, one end of the No. 2 hydraulic press is movably connected to the No. 2 telescopic rod, the No. 2 telescopic rod is abutted against the No. 2 shell, a No. 3 hydraulic press is arranged inside the No. 2 shell, one end of the No. 3 hydraulic press is movably connected to the No. 3 telescopic rod, one end of the No. 3 telescopic rod is abutted against the connecting block, both ends of the connecting block are movably connected to a No. 1 connecting piece and a No. 2 connecting piece, the No. 1 connecting piece is movably connected to the No. 3 connecting piece, the No. 3 connecting piece is movably connected to the No. 1 sector gear through the No. 1 connecting column, the No. 2 connecting piece is movably connected to the No. 4 connecting piece, the No. 4 connecting piece is movably connected to the No. 2 sector gear through the No. 2 connecting column, the No. 1 sector gear and the No. 2 sector gear are respectively meshed and connected to the No. 1 rack and the No. 2 rack, and the upper ends of the No. 1 rack and the No. 2 rack are respectively fixedly connected to the No. 1 clamp and the No. 2 clamp.

[0008] Preferably, the separation device comprises a No. 1 servo motor and a No. 3 housing, the No. 1 servo motor is connected to a gear through a rotating shaft, the rotating shaft passes through the No. 3 housing, the gear is arranged in the No. 3 housing, the gear is meshingly connected to a No. 3 rack and a No. 4 rack, the upper end of the No. 3 rack is fixedly connected to a No. 1 support block, the upper end of the No. 1 support block is movably connected to a No. 1 synchronous wheel, one end of the No. 1 synchronous wheel is transmission-connected to a No. 2 servo motor, a No. 1 synchronous wheel is surrounded by a transmission belt, a No. 2 support block is arranged at one end of the No. 4 rack, the upper end of the No. 2 support block is movably connected to the No. 2 synchronous wheel, one end of the No. 2 synchronous wheel is transmission-connected to a No. 3 servo motor, and a No. 2 transmission belt is arranged around the No. 1 synchronous wheel.

[0009] Preferably, the No. 1 connecting column and the No. 2 connecting column are penetrated through the No. 1 outer shell.

[0010] Preferably, a No. 1 slide block is provided at the upper end of the No. 2 housing, and a No. 1 slide groove matched with the No. 1 slide block is provided at the lower ends of the No. 1 rack and the No. 2 rack.

[0011] Preferably, three first synchronous wheels are provided, and three second synchronous wheels are provided.

[0012] Preferably, a No. 2 slider is arranged inside the No. 3 shell, and two No. 2 sliders are arranged. The lower ends of the No. 3 rack and the No. 4 rack are provided with a No. 2 slide groove adapted to the No. 2 slider, and the other ends of the No. 3 rack and the No. 4 rack are provided with a limit plate.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] The utility model cooperates with a positioning device and a separation device. The first clamp and the second clamp of the positioning device clamp one end of the base station antenna with a reflector bottom plate (at this time, there is no bracket connected to it on the base station antenna cover). After clamping the column, the base station antenna is pushed toward the positioning device and pushed between the first support block and the second support block of the separation device. The first support block and the second support block clamp the other end of the base station antenna cover. At this time, the cover contacts the first and second synchronous wheels on the first and second support blocks, and then the first and second synchronous wheels rotate to drive the cover to separate from the reflector. After the cover is separated from the reflector, the cover is then rotated to separate it outside, thereby avoiding rapid fatigue caused by long-term manual separation of the cover and the reflector of the base station antenna, saving time and effort. At the same time, the separated cover and the reflector are not in the same place, thereby avoiding the increase in time cost caused by mixing them together. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a three-dimensional diagram of the separation equipment of the utility model;

[0016] Figure 2 yes Figure 1 The internal schematic diagram of the positioning device at A in the middle;

[0017] Figure 3 yes Figure 1 Schematic diagram of the interior of the separation device at B in the middle;

[0018] Figure 4 It is a side view of the third bracket of the utility model.

[0019] In the figure:

[0020] 1. Base; 2. No. 1 hydraulic press; 3. No. 1 telescopic rod; 4. No. 1 bracket; 401. Unloading table; 5. No. 2 bracket; 6. Positioning device; 7. Support plate; 8. No. 3 bracket; 9. Separation device; 61. No. 1 shell; 62. No. 2 hydraulic press; 63. No. 2 telescopic rod; 64. No. 2 shell; 65. No. 3 hydraulic press; 66. No. 3 telescopic rod; 67. Connecting block; 68. No. 1 connecting piece; 69. No. 2 connecting piece; 610. No. 3 connecting piece; 611. No. 1 connecting column; 612. No. 1 sector gear; 613. No. 4 connecting piece; 614. No. 2 connecting column; 615. No. 2 sector gear Wheel; 616, rack No. 1; 617, rack No. 2; 618, gripper No. 1; 619, gripper No. 2; 620, slider No. 1; 621, slide No. 1; 91, servo motor No. 1; 92, gear; 93, rack No. 3; 94, rack No. 4; 95, support block No. 1; 96, synchronous wheel No. 1; 97, servo motor No. 2; 98, transmission belt No. 1; 99, support block No. 2; 910, synchronous wheel No. 2; 911, servo motor No. 3; 912, transmission belt No. 2; 913, rotating shaft; 914, housing No. 3; 915, slider No. 2; 916, slide No. 2; 917, limit plate. DETAILED DESCRIPTION

[0021] The following is a further detailed description of the implementation of the present invention in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0022] like Figures 1 to 4 As shown, a base station antenna recovery and separation device includes a base 1, a positioning device 6 and a separation device 9, a No. 1 hydraulic press 2 is arranged on the upper end of the base 1, a No. 1 telescopic rod 3 is movably connected to the upper end of the No. 1 hydraulic press 2, a No. 1 telescopic rod 3 is fixedly connected to the upper end of the No. 1 telescopic rod 3 with a discharge table 401, a No. 1 bracket 4 and a No. 2 bracket 5 are arranged on both sides of the base 1, a positioning device 6 is arranged on the upper end of the No. 1 bracket 4, a support plate 7 is arranged on the upper end of the No. 2 bracket 5, a No. 3 bracket 8 is arranged on the upper end of the support plate 7, and a separation device 9 is arranged on the upper end of the No. 3 bracket 8.

[0023] When recycling and separating the base station antenna, it is necessary to disassemble it first, place a base station antenna (at this time, there is no bracket connected to it on the base station antenna cover) on the unloading table 401, lean it against the edge of the unloading table 401, and face one end of the reflector base to the positioning device 6, and the other end to the separation device 9, then start the No. 1 hydraulic press 2, and the No. 1 hydraulic press 2 drives the No. 1 telescopic rod 3 to raise the unloading table 401 to a suitable position.

[0024] As a specific embodiment of the present utility model, the positioning device 6 includes a No. 1 shell 61, a No. 2 hydraulic press 62 is arranged inside the No. 1 shell 61, one end of the No. 2 hydraulic press 62 is movably connected to a No. 2 telescopic rod 63, the No. 2 telescopic rod 63 is abutted against the No. 2 shell 64, a No. 3 hydraulic press 65 is arranged inside the No. 2 shell 64, one end of the No. 3 hydraulic press 65 is movably connected to a No. 3 telescopic rod 66, one end of the No. 3 telescopic rod 66 is abutted against a connecting block 67, and both ends of the connecting block 67 are movably connected to a No. 1 connecting piece 68 and a No. 2 connecting piece 69, and the No. 1 connecting piece 68 is movably connected to the No. 3 connecting piece 6 10. The third connecting member 610 is movably connected to the first sector gear 612 through the first connecting column 611. The second connecting member 69 is movably connected to the fourth connecting member 613. The fourth connecting member 613 is movably connected to the second sector gear 615 through the second connecting column 614. The first connecting column 611 and the second connecting column 614 are penetrated by the first housing 61. The first sector gear 612 and the second sector gear 615 are respectively meshed and connected with the first rack 616 and the second rack 617. The upper ends of the first rack 616 and the second rack 617 are respectively fixedly connected with the first clamp 618 and the second clamp 619.

[0025] When preparing to disassemble the base station antenna, the distance between the No. 1 clamp 618 and the No. 2 clamp 619 is the largest. When the unloading platform 401 raises the base station antenna to a suitable position, the end of the base station antenna with the reflector base is between the No. 1 clamp 618 and the No. 2 clamp 619. The No. 2 hydraulic press 62 drives the No. 2 telescopic rod 63 to move forward, the No. 2 telescopic rod 63 drives the No. 2 housing 64, and the No. 2 housing 64 drives the No. 1 clamp 618 and the No. 2 clamp 619 to move forward to a suitable position, and then the No. 3 hydraulic press 65 drives the No. 3 telescopic rod 66 to move forward, the No. 3 telescopic rod 66 drives the connecting block 67, and the connecting block 67 drives the No. 1 connecting piece 68 and the No. 2 connecting piece 69 that are movably connected at both ends of the connecting block 67, drives the No. 3 connecting piece 610 that is movably connected to the No. 1 connecting piece 68, and drives the No. 1 sector gear 612 that is movably connected to the No. 3 connecting piece 610 through the No. 1 connecting column 611. , driving the No. 4 connecting piece 613 movably connected to the No. 2 connecting piece 69, driving the No. 2 fan gear 615 movably connected to the No. 4 connecting piece 613 through the No. 2 connecting column 614, driving the No. 1 fan gear 612 and the No. 2 fan gear 615 respectively meshing with the No. 1 rack 616 and the No. 2 rack 617 drive the No. 1 clamp 618 and the No. 2 clamp 619 to move in parallel until one end of the base station antenna with the reflector base is clamped, and then the No. 2 hydraulic press 62 continues to drive the No. 2 telescopic rod 63 forward to push the other end of the base station antenna into the separation device 9.

[0026] As a specific embodiment of the present utility model, the separation device 9 includes a No. 1 servo motor 91 and a No. 3 housing 914. The No. 1 servo motor 91 is connected to a gear 92 through a rotating shaft 913. The rotating shaft 913 is penetrated by the No. 3 housing 914. The gear 92 is arranged in the No. 3 housing 914. The gear 92 is meshed and connected with a No. 3 rack 93 and a No. 4 rack 94. The upper end of the No. 3 rack 93 is fixedly connected to a No. 1 support block 95. The upper end of the No. 1 support block 95 is movably connected to a No. A synchronous wheel 96, one end of the No. 1 synchronous wheel 96 is transmission-connected to a No. 2 servo motor 97, a No. 1 transmission belt 98 is sleeved around the No. 1 synchronous wheel 96, a No. 2 support block 99 is provided at one end of the No. 4 rack 94, a No. 2 synchronous wheel 910 is movably connected to the upper end of the No. 2 support block 99, one end of the No. 2 synchronous wheel 910 is transmission-connected to a No. 3 servo motor 911, a No. 2 transmission belt 912 is sleeved around the No. 2 synchronous wheel 910, three No. 1 synchronous wheels 96 are provided, and three No. 2 synchronous wheels 910 are provided.

[0027] When preparing to disassemble the base station antenna, the distance between the No. 1 support block 95 and the No. 2 support block 99 is the largest. When the other end of the base station antenna is between the No. 1 support block 95 and the No. 2 support block 99, the No. 1 servo motor 91 drives the gear 92 connected by the rotating shaft 913, and the gear 92 drives the meshing rack 93 and the No. 4 rack 94 to move toward the middle until the other end of the base station antenna is clamped. At this time, the No. 1 transmission belt 98 and the No. 2 transmission belt 912 outside the three No. 1 synchronous wheels 96 and the three No. 2 synchronous wheels 910 on the No. 1 support block 95 and the No. 2 support block 99 are against the other end of the base station antenna, and then the No. 2 servo motor 97 rotates counterclockwise, and the No. 3 servo motor 911 rotates clockwise, driving the No. 1 synchronization wheel 96 and the No. 2 synchronization wheel 910. The outer cover of the base station antenna is away from the separation device under the action of the No. 1 transmission belt 98 and the No. 2 transmission belt 912 until it falls to the ground.

[0028] It avoids quick fatigue caused by long-term manual separation of the outer cover and reflector of the base station antenna, saving time and effort. At the same time, the separated outer cover and reflector are not in the same location, avoiding the increase in time cost caused by mixing them together.

[0029] As a specific implementation of the utility model, a No. 1 slider 620 is disposed at the upper end of the No. 2 housing 64 , and a No. 1 slide groove 621 adapted to the No. 1 slider 620 is provided at the lower ends of the No. 1 rack 616 and the No. 2 rack 617 .

[0030] The first slider 620 slides in the first slide groove 621 matched therewith, so that the first sector gear 612 and the second sector gear 615 can better drive the first rack 616 and the second rack 617 to move inwardly.

[0031] As a specific implementation of the utility model, a No. 2 slider 915 is arranged inside the No. 3 shell 914, and two No. 2 sliders 915 are arranged. The lower ends of the No. 3 rack 93 and the No. 4 rack 94 are provided with a No. 2 slide groove 916 adapted to the No. 2 slider 915, and the other ends of the No. 3 rack 93 and the No. 4 rack 94 are provided with a limiting plate 917.

[0032] The second slider 915 slides in the second slide groove 916 adapted thereto, so that the gear 92 can better drive the third rack 93 and the fourth rack 94 to move in the middle. The limit plate 917 can prevent the third rack 93 and the fourth rack 94 from moving outwards too far.

[0033] Specific working principle:

[0034] When recycling and separating the base station antenna, it is necessary to disassemble it first, place a base station antenna (at this time, there is no bracket connected to it on the base station antenna cover) on the unloading table 401, lean it against the edge of the unloading table 401, and face one end of the reflector base to the positioning device 6, and the other end to the separation device 9, then start the No. 1 hydraulic press 2, and the No. 1 hydraulic press 2 drives the No. 1 telescopic rod 3 to raise the unloading table 401 to a suitable position.

[0035] When the unloading platform 401 raises the base station antenna to a suitable position, the end of the base station antenna with the reflector base is between the No. 1 clamp 618 and the No. 2 clamp 619. The No. 2 hydraulic press 62 drives the No. 2 telescopic rod 63 to move forward, the No. 2 telescopic rod 63 drives the No. 2 housing 64, the No. 2 housing 64 drives the No. 1 clamp 618 and the No. 2 clamp 619 to move forward to a suitable position, and then the No. 3 hydraulic press 65 drives the No. 3 telescopic rod 66 to move forward, the No. 3 telescopic rod 66 drives the connecting block 67, the connecting block 67 drives the No. 1 connecting piece 68 and the No. 2 connecting piece 69 movably connected at both ends of the connecting block 67, drives the No. 3 connecting piece 610 movably connected to the No. 1 connecting piece 68, and drives the No. 1 sector gear 612 movably connected to the No. 3 connecting piece 610 through the No. 1 connecting column 611. , driving the No. 4 connecting piece 613 movably connected to the No. 2 connecting piece 69, driving the No. 2 fan gear 615 movably connected to the No. 4 connecting piece 613 through the No. 2 connecting column 614, driving the No. 1 fan gear 612 and the No. 2 fan gear 615 respectively meshing with the No. 1 rack 616 and the No. 2 rack 617 drive the No. 1 clamp 618 and the No. 2 clamp 619 to move in parallel until one end of the base station antenna with the reflector base is clamped, and then the No. 2 hydraulic press 62 continues to drive the No. 2 telescopic rod 63 forward to push the other end of the base station antenna into the separation device 9.

[0036] When the other end of the base station antenna is between the No. 1 support block 95 and the No. 2 support block 99, the No. 1 servo motor 91 drives the gear 92 connected by the rotating shaft 913, and the gear 92 drives the meshing connected No. 3 rack 93 and the No. 4 rack 94 to move toward the middle until the other end of the base station antenna is clamped. At this time, the No. 1 transmission belt 98 and the No. 2 transmission belt 912 outside the three No. 1 synchronous wheels 96 and the three No. 2 synchronous wheels 910 on the No. 1 support block 95 and the No. 2 support block 99 are against the other end of the base station antenna. Then the No. 2 servo motor 97 rotates counterclockwise, and the No. 3 servo motor 911 rotates clockwise, driving the No. 1 synchronous wheel 96 and the No. 2 synchronous wheel 910. The outer cover of the base station antenna is moved away from the separation device under the action of the No. 1 transmission belt 98 and the No. 2 transmission belt 912 until it falls to the ground, and then the reflector on the discharge table 401 is taken down to disassemble the next base station antenna.

[0037] It avoids the rapid fatigue caused by long-term manual separation of the outer cover and reflector of the base station antenna, saving time and effort. At the same time, the separated outer cover and reflector are not in the same location, avoiding the increase in time cost caused by mixing them together.

[0038] The embodiments of the present invention are provided for the purpose of illustration and description. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A base station antenna recovery and separation device, characterized in that: The utility model comprises a base (1), a positioning device (6) and a separating device (9), wherein a No. 1 hydraulic press (2) is arranged at the upper end of the base (1), a No. 1 telescopic rod (3) is movably connected to the upper end of the No. 1 hydraulic press (2), a No. 1 telescopic rod (3) is fixedly connected to the upper end of the No. 1 telescopic rod (3) and a material discharge platform (401) are arranged at the upper end of the base (1), a No. 1 bracket (4) and a No. 2 bracket (5) are arranged at both sides of the base (1), a positioning device (6) is arranged at the upper end of the No. 1 bracket (4), a support plate (7) is arranged at the upper end of the No. 2 bracket (5), a No. 3 bracket (8) is arranged at the upper end of the support plate (7), and a separating device (9) is arranged at the upper end of the No. 3 bracket (8).

2. The base station antenna recovery and separation device as claimed in claim 1, characterized in that: The positioning device (6) comprises a first housing (61), a second hydraulic press (62) is arranged inside the first housing (61), one end of the second hydraulic press (62) is movably connected to a second telescopic rod (63), the second telescopic rod (63) abuts against the second housing (64), a third hydraulic press (65) is arranged inside the second housing (64), one end of the third hydraulic press (65) is movably connected to a third telescopic rod (66), one end of the third telescopic rod (66) abuts against a connecting block (67), two ends of the connecting block (67) are movably connected to a first connecting piece (68) and a second connecting piece (69), the first connecting piece (68) is movably connected to the second connecting piece (69), and the first connecting piece (68) is movably connected to the second connecting piece (69). A No. 3 connecting member (610) is connected, and the No. 3 connecting member (610) is movably connected to a No. 1 fan-shaped gear (612) through a No. 1 connecting column (611). The No. 2 connecting member (69) is movably connected to a No. 4 connecting member (613). The No. 4 connecting member (613) is movably connected to a No. 2 fan-shaped gear (615) through a No. 2 connecting column (614). The No. 1 fan-shaped gear (612) and the No. 2 fan-shaped gear (615) are respectively meshed and connected to a No. 1 rack (616) and a No. 2 rack (617). The upper ends of the No. 1 rack (616) and the No. 2 rack (617) are respectively fixedly connected to a No. 1 clamp (618) and a No. 2 clamp (619).

3. The base station antenna recovery and separation device as claimed in claim 1, characterized in that: The separation device (9) comprises a No. 1 servo motor (91) and a No. 3 housing (914); the No. 1 servo motor (91) is connected to a gear (92) via a rotating shaft (913); the rotating shaft (913) passes through the No. 3 housing (914); the gear (92) is arranged in the No. 3 housing (914); the gear (92) is meshedly connected to a No. 3 rack (93) and a No. 4 rack (94); the upper end of the No. 3 rack (93) is fixedly connected to a No. 1 support block (95); the upper end of the No. 1 support block (95) A first synchronous wheel (96) is movably connected, one end of the first synchronous wheel (96) is transmission-connected to a second servo motor (97), a first transmission belt (98) is sleeved around the first synchronous wheel (96), a second support block (99) is arranged at one end of the fourth rack (94), a second synchronous wheel (910) is movably connected to the upper end of the second support block (99), one end of the second synchronous wheel (910) is transmission-connected to a third servo motor (911), and a second transmission belt (912) is sleeved around the second synchronous wheel (910).

4. The base station antenna recovery and separation device as claimed in claim 2, characterized in that: The first connecting column (611) and the second connecting column (614) are disposed through the first housing (61).

5. The base station antenna recovery and separation device as claimed in claim 2, characterized in that: A first slide block (620) is disposed at the upper end of the second housing (64), and a first slide groove (621) adapted to the first slide block (620) is provided at the lower ends of the first rack (616) and the second rack (617).

6. The base station antenna recovery and separation device as claimed in claim 3, characterized in that: The number one synchronous wheels (96) are provided in three pieces, and the number two synchronous wheels (910) are provided in three pieces.

7. The base station antenna recovery and separation device as claimed in claim 3, characterized in that: A No. 2 slider (915) is arranged inside the No. 3 housing (914), and two No. 2 sliders (915) are arranged. A No. 2 slide groove (916) adapted to the No. 2 slider (915) is provided at the lower ends of the No. 3 rack (93) and the No. 4 rack (94), and a limiting plate (917) is arranged at the other ends of the No. 3 rack (93) and the No. 4 rack (94).

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