Adjustable neck support suitable for dental chair

Abstract

The utility model discloses an adjustable neck collar suitable for a dental chair, and relates to the technical field of medical instruments. The clamp comprises a mounting box and two groups of clamping blocks used for clamping two supporting rods, each group of clamping blocks comprises an inner clamping block and an outer clamping block which are oppositely arranged, and the supporting rods, the inner clamping blocks and the outer clamping blocks are symmetrically arranged. The mounting box is provided with an inner clamping mechanism fixedly connected with the inner clamping block and an outer clamping mechanism fixedly connected with the outer clamping block. By means of the inner clamping mechanism, the gear rotates synchronously, drives the two racks to be away from each other and pushes the moving strips to be away from each other until the two inner clamping blocks forcefully clamp the supporting rod in one step, the mounting box is effectively fixed to one side of the supporting rod by clamping the different sides of the supporting rod, the mounting box is prevented from sliding, and the mounting box is convenient to use. And the stability of the mounting box and the neck support plate is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of medical equipment, in particular to an adjustable neck support suitable for a dental chair. Background Art

[0002] The dental chair is one of the essential equipment in the dental clinic. It is mainly used to support and adjust the patient's body position so that the dentist can better perform oral treatment. During dental treatment, the patient's head and neck need to be stably supported to ensure the patient's comfort and the dentist's convenience. However, most existing dental chairs use fixed neck braces that cannot be adjusted according to the patient's specific needs, causing some patients to feel neck discomfort during treatment.

[0003] In addition, due to the differences in body shape and needs of different patients, the fixed cervical brace cannot adapt to all patients, resulting in some patients being unable to obtain effective neck support during treatment. In addition, the usual installation method of the cervical brace, which uses splints and bolts, is cumbersome to operate and provides poor support. When the patient squeezes the cervical brace, the fixing plate may move, thereby causing the position of the cervical brace to move. Therefore, an adjustable cervical brace suitable for dental chairs is needed to solve the existing deficiencies. Utility Model Content

[0004] The purpose of the utility model is to provide an adjustable neck support suitable for a dental chair, which effectively fixes the installation box to one side of the support rod through the internal clamping mechanism to prevent it from sliding, thereby improving the stability of the installation box and the neck support plate; the external clamping mechanism is provided to facilitate users to adjust from any side, thereby facilitating the rapid installation and removal of the neck support plate; the angle adjustment mechanism is provided to facilitate the necks of different patients to be adequately supported, which is conducive to their obtaining a more comfortable neck experience during dental surgery.

[0005] In order to solve the above technical problems, the utility model is realized by the following technical solutions:

[0006] The utility model discloses an adjustable neck support suitable for a dental chair, which is fixed on two supporting rods of the dental chair and comprises a mounting box and two groups of clamping blocks for clamping the two supporting rods, each group of clamping blocks comprises an inner clamping block and an outer clamping block which are arranged opposite to each other, the supporting rods, the inner clamping blocks and the outer clamping blocks are all arranged symmetrically, the mounting box is provided with an inner clamping mechanism which is fixedly connected to the inner clamping block and an outer clamping mechanism which is fixedly connected to the outer clamping block, the inner clamping mechanism and the outer clamping mechanism can respectively drive the inner clamping block and the outer clamping block to move in directions of approaching or moving away from each other, an angle adjustment mechanism is arranged on the outer side of the mounting box, and a neck support plate is fixedly connected to one end of the angle adjustment mechanism which is away from the mounting box.

[0007] The utility model is further configured as follows: the internal clamping mechanism includes a rotary column, a gear, two racks, and a control member extending to the outside of the mounting box and penetrating the mounting box and fixedly connected to the rotary column; the rotary column penetrates the gear and is fixedly connected to the gear; the gear is located between the two racks and respectively meshes with the two racks; the two racks are respectively connected to one of the inner clamping blocks via a connecting member passing through the mounting box; the two racks are symmetrical about the axis of the rotary column as the origin; and the gear is movably connected to the inside of the mounting box via the rotary column.

[0008] The utility model is further configured as follows: the control member 1 includes a cross block and a knob 1, the rotary column is provided with a connecting hole matching the cross block, the cross block is plugged into and matched with the connecting hole of the rotary column, the knob 1 is located outside the installation box, and the bottom end of the knob 1 passes through the installation box and is fixedly connected to the cross block, the outer periphery of the knob 1 adjacent to its bottom end is provided with a thread, and the knob 1 is screwed to the installation box thread.

[0009] The utility model is further configured that the connecting member includes a group of symmetrical moving bars fixedly connected to the bottom end of the inner clamping block, and one end of the moving bar away from the inner clamping block passes through the installation box and is fixedly connected to the rack.

[0010] The utility model is further configured as follows: the external clamping mechanism includes two symmetrically arranged moving blocks, an adjusting rod and two knobs located outside the installation box, the two ends of the adjusting rod respectively pass through the installation box and are fixedly connected to the knobs, and the installation box is movably connected to the adjusting rod, a group of symmetrical threads are opened on the outside of the adjusting rod, the moving block passes through the installation box, and one end of the moving block extends to the outside of the installation box and is fixedly connected to the external clamping block, and the moving block is located adjacent to its other end inside the installation box and is threadedly connected to the adjusting rod.

[0011] The utility model is further configured as follows: the angle adjustment mechanism includes a pair of teeth one, a pair of teeth two, a control rod, a support block, a rotary rod and a knob three, the pair of teeth one is fixedly connected to one end of the control rod, and the knob three is fixedly connected to the other end of the control rod, the pair of teeth one is meshed with the pair of teeth two, the support block and the rotary rod are a group and there are two groups in total, and each group of support blocks is symmetrically arranged, one end of the rotary rod passes through the support block, and the rotary rod is movably connected to the support block, and the other end of the rotary rod is movably connected to the inside of the support block.

[0012] The utility model is further configured as follows: the angle adjustment mechanism also includes a reset spring and a spacer ring, the spacer ring and the reset spring can be sleeved on the outside of the control rod, one end of the reset spring is fixedly connected to the support block, and the other end of the reset spring is fixedly connected to one side of the spacer ring, the other side of the spacer ring is fitted with the back side of the first tooth, the second tooth is fixedly connected to one side of the support block, the control rod passes through the rotary rod, and the control rod is movably connected to the rotary rod, the outside of the rotary rod is fixedly connected with a group of symmetrical connecting plates, and the other end of the connecting plates is fixedly connected to the back side of the neck support plate.

[0013] The utility model has the following beneficial effects:

[0014] 1. The utility model sets up an internal clamping mechanism to make the gears rotate synchronously, drive the two racks to move away from each other, and push the moving bars to move away from each other until the two internal clamping blocks clamp the support rod forcefully in one step. By clamping different sides of the support rod, the installation box is effectively fixed to one side of the support rod to prevent it from sliding, thereby improving the stability of the installation box and the neck support plate.

[0015] 2. The utility model provides an external clamping mechanism, by turning the second knob, the adjusting rod is driven to rotate. Since the adjusting rod is threadedly connected to the moving block, the external clamping blocks are brought closer to each other until the two external clamping blocks clamp the supporting block forcefully. Knobs 2 are provided at both ends of the installation box, which is convenient for the user to adjust from either side, thereby facilitating the rapid installation and removal of the neck support plate.

[0016] 3. The utility model is provided with an angle adjustment mechanism. By pulling the knob three outward, the control rod is driven to move inside the rotating rod, so that the tooth one is separated from the tooth two, and the spacer ring is driven to move, so that the reset spring is compressed and shortened. Then, the knob is turned, and the control rod drives the rotating rod to rotate synchronously. Under the action of the connecting plate, the neck support plate is driven to rotate synchronously around the rotating rod, thereby completing the angle adjustment, so that the necks of different patients can get sufficient support, which is conducive to their obtaining a more comfortable neck experience during dental surgery.

[0017] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 It is a three-dimensional structural schematic diagram of the utility model;

[0020] Figure 2 This is a structural schematic diagram of another viewing angle of the utility model;

[0021] Figure 3 It is a schematic diagram of the structure of the inner clamping mechanism and the outer clamping mechanism of the utility model;

[0022] Figure 4 This is a schematic diagram of the angle adjustment mechanism structure of the utility model;

[0023] Figure 5 For this utility model Figure 3 A schematic diagram of the enlarged structure at A in the middle;

[0024] Figure 6 For this utility model Figure 4 Schematic diagram of the enlarged structure at point B in the middle.

[0025] In the figure: 1. support rod; 2. mounting box; 3. inner clamping block; 4. outer clamping block; 5. inner clamping mechanism; 501. rotary column; 502. gear; 503. rack; 504. cross block; 505. knob one; 6. outer clamping mechanism; 601. moving block; 602. adjusting rod; 603. knob two; 7. angle adjustment mechanism; 701. gear one; 702. gear two; 703. control rod; 704. support block; 705. rotary rod; 706. knob three; 707. reset spring; 708. spacer ring; 8. neck support plate; 9. moving bar; 10. connecting plate. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] like Figure 1-6 As shown, the utility model provides a technical solution: an adjustable neck support suitable for a dental chair, fixed on two support rods 1 of the dental chair, comprising a mounting box 2 and two groups of clamping blocks for clamping the two support rods 1, each group of clamping blocks comprising an inner clamping block 3 and an outer clamping block 4 arranged opposite to each other, the support rods 1, the inner clamping block 3 and the outer clamping block 4 are symmetrically arranged, the mounting box 2 is provided with an inner clamping mechanism 5 fixedly connected to the inner clamping block 3 and an outer clamping mechanism 6 fixedly connected to the outer clamping block 4, the inner clamping mechanism 5 and the outer clamping mechanism 6 can respectively drive the inner clamping block 3 and the outer clamping block 4 to move in directions of approaching or moving away from each other, an angle adjustment mechanism 7 is provided on the outer side of the mounting box 2, and a neck support plate 8 is fixedly connected to the end of the angle adjustment mechanism 7 away from the mounting box 2.

[0028] First, the two ends of the support rod 1 are respectively connected to the backrest and headrest of the dental chair, then, the support rod 1 is placed on the opposite sides of the inner clamping block 3 and the outer clamping block 4, then, the knob 2 603 is turned to drive the adjusting rod 602 to rotate, and since the adjusting rod 602 is threadedly connected to the moving block 601, the outward clamping blocks 4 are made to approach each other until the two outer clamping blocks 4 clamp the supporting block 704 effectively, and knobs 2 603 are provided at both ends of the installation box 2, which is convenient for the user to adjust from either side; then, the knob 1 505 in the middle position of the installation box 2 is turned, and the knob 1 505 is turned inward to drive the cross block 504 to rotate synchronously. Since the cross block 504 and the rotary column 501 are movably connected, the cross block 504 also rotates inward during the movement, thereby driving the rotary column 501 to rotate, and does not cause the rotary column 501 to move synchronously, thereby making The gear 502 rotates synchronously, driving the two racks 503 away from each other, pushing the moving bars 9 away from each other, until the two inner clamping blocks 3 clamp the support rod 1 in one step, and by clamping the different sides of the support rod 1, the mounting box 2 is effectively fixed to one side of the support rod 1 to prevent it from sliding; then the angle of the neck support plate 8 is adjusted as needed so that the neck support plate 8 can better support the patient's neck, and by pulling the knob three 706 outward, the control rod 703 is driven to move inside the rotating rod 705, so that the tooth one 701 is separated from the tooth two 702, and the spacer ring 708 is driven to move, so that the reset spring 707 is compressed and shortened, and then the knob is turned, and the control rod 703 drives the rotating rod 705 to rotate synchronously. Under the action of the connecting plate 10, the neck support plate 8 is driven to rotate synchronously around the rotating rod 705, thereby completing the angle adjustment.

[0029] like Figure 1 , Figure 3 and Figure 5As shown, the inner clamping mechanism 5 includes a rotating column 501, a gear 502, two racks 503 located in the installation box 2, and a control member 1 extending to the outside of the installation box 2 and penetrating the installation box 2 and fixedly connected to the rotating column 501. The rotating column 501 penetrates the gear 502 and is fixedly connected to the gear 502. The gear 502 is located between the two racks 503 and meshes with the two racks 503 respectively. The two racks 503 are respectively connected to one of the inner clamping blocks 3 through a connecting member passing through the installation box 2. The two racks 503 are symmetrical about the axis of the rotating column 501 as the origin. The gear 502 is movably connected to the inner of the installation box 2 through the rotating column 501. The control part 1 includes a cross block 504 and a knob 1 505. The rotary column 501 is provided with a connecting hole matched with the cross block 504. The cross block 504 is plugged into the connecting hole of the rotary column 501. The knob 1 505 is located on the outside of the installation box 2, and the bottom end of the knob 1 505 passes through the installation box 2 and is fixedly connected to the cross block 504. The outer periphery of the knob 1 505 adjacent to its bottom end is provided with a thread, and the knob 1 505 is screwed with the installation box 2. The connecting part includes a group of symmetrical moving bars 9 fixedly connected to the bottom end of the inner clamping block 3, and the end of the moving bar 9 away from the inner clamping block 3 passes through the installation box 2 and is fixedly connected to the rack 503.

[0030] The cross block 504 is driven by the screw thread 502 to rotate synchronously, and the screw thread 501 is prevented from moving synchronously, thereby the gear 502 is driven to rotate synchronously, and the two racks 503 are driven to move away from each other, and the moving bars 9 are pushed away from each other, until the two inner clamping blocks 3 clamp the support rod 1 in one step, and the installation box 2 is effectively fixed to one side of the support rod 1 by clamping different sides of the support rod 1 to prevent it from sliding, thereby improving the stability of the installation box 2 and the neck support plate 8.

[0031] like Figure 1 , Figure 3 and Figure 5 As shown, two symmetrically arranged moving blocks 601, an adjusting rod 602 and two knobs 603 located on the outside of the installation box 2, both ends of the adjusting rod 602 respectively pass through the installation box 2 and are fixedly connected to the knobs 603, and the installation box 2 is movably connected to the adjusting rod 602, and a group of symmetrical threads are opened on the outside of the adjusting rod 602, the moving block 601 passes through the installation box 2, and one end of the moving block 601 extends to the outside of the installation box 2 and is fixedly connected to the outer clamping block 4, and the moving block 601 is located adjacent to its other end inside the installation box 2 and is threadedly connected to the adjusting rod 602.

[0032] Turning knob 2 603 drives the adjusting rod 602 to rotate. Since the adjusting rod 602 is threadedly connected to the moving block 601, the outward clamping blocks 4 are moved closer to each other until the two outer clamping blocks 4 firmly clamp the supporting block 704. Knobs 2 603 are provided at both ends of the installation box 2, which is convenient for the user to adjust from either side, thereby facilitating the quick installation and removal of the neck support plate 8.

[0033] like Figure 1 , Figure 4 and Figure 6 As shown, the angle adjustment mechanism 7 includes a pair of teeth 1 701, a pair of teeth 2 702, a control rod 703, a support block 704, a rotary rod 705 and a knob 3 706. The pair of teeth 1 701 is fixedly connected to one end of the control rod 703, and the knob 3 706 is fixedly connected to the other end of the control rod 703. The pair of teeth 1 701 is meshed with the pair of teeth 2 702. The support block 704 and the rotary rod 705 are a group and there are two groups in total, and each group of support blocks 704 is symmetrically arranged. One end of the rotary rod 705 passes through the support block 704, and the rotary rod 705 is movably connected to the support block 704. The other end of the rotary rod 705 is movably connected to the inside of the support block 704. The angle adjustment mechanism 7 It also includes a reset spring 707 and a spacer ring 708, and the spacer ring 708 and the reset spring 707 can be sleeved on the outside of the control rod 703, one end of the reset spring 707 is fixedly connected to the support block 704, and the other end of the reset spring 707 is fixedly connected to one side of the spacer ring 708, the other side of the spacer ring 708 is in contact with the back side of the tooth 1 701, and the tooth 2 702 is fixedly connected to one side of the support block 704, the control rod 703 passes through the rotary rod 705, and the control rod 703 is movably connected to the rotary rod 705, and a group of symmetrical connecting plates 10 are fixedly connected to the outside of the rotary rod 705, and the other end of the connecting plate 10 is fixedly connected to the back side of the neck support plate 8.

[0034] By pulling knob three 706 outward, the control rod 703 is driven to move inside the rotating rod 705, so that the tooth one 701 is separated from the tooth two 702, and the spacer ring 708 is driven to move, so that the reset spring 707 is compressed and shortened, and then the knob is turned, and the control rod 703 drives the rotating rod 705 to rotate synchronously. Under the action of the connecting plate 10, the neck support plate 8 is driven to rotate synchronously around the rotating rod 705, thereby completing the angle adjustment, so that the necks of different patients can get sufficient support, which is conducive to their having a more comfortable neck experience during dental surgery.

[0035] This embodiment also provides a dental chair, including a chair back and a headrest, wherein the chair back is connected to the headrest via two support rods 1, and an adjustable neck support is mounted on the two support rods 1 and is located between the chair back and the headrest.

[0036] Working principle: When in use, first, the two ends of the support rod 1 are connected to the backrest and headrest of the dental chair respectively, then, the support rod 1 is placed on the opposite sides of the inner clamping block 3 and the outer clamping block 4 respectively, and then, the knob 2 603 is turned to drive the adjusting rod 602 to rotate. Since the adjusting rod 602 is threadedly connected to the moving block 601, the outward clamping blocks 4 are close to each other until the two outer clamping blocks 4 clamp the supporting block 704 forcefully. Knobs 2 603 are provided at both ends of the installation box 2, which is convenient for the user to adjust from either side; then, turn the knob 1 505 in the middle position of the installation box 2, and turn the knob 1 505 inward to drive the cross block 504 to rotate synchronously. Since the cross block 504 and the rotary column 501 are movably connected, the cross block 504 also rotates inward during the movement, thereby driving the rotary column 501 to rotate, and the rotary column 501 will not move synchronously. , thereby making the gear 502 rotate synchronously, driving the two racks 503 away from each other, pushing the moving bars 9 away from each other, until the two inner clamping blocks 3 clamp the support rod 1 in one step, and by clamping the different sides of the support rod 1, the mounting box 2 is effectively fixed to one side of the support rod 1 to prevent it from sliding; then the angle of the neck support plate 8 is adjusted as needed, so that the neck support plate 8 can better support the patient's neck, by pulling the knob three 706 outward, driving the control rod 703 to move inside the rotating rod 705, so that the tooth one 701 and the tooth two 702 are separated, driving the spacer ring 708 to move, so that the reset spring 707 is compressed and shortened, and then the knob is turned, the control rod 703 drives the rotating rod 705 to rotate synchronously, and under the action of the connecting plate 10, the neck support plate 8 is driven to rotate synchronously around the rotating rod 705, thereby completing the angle adjustment.

[0037] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0038] The preferred embodiments of the utility model disclosed above are only used to help explain the utility model. The preferred embodiments do not describe all the details in detail, nor do they limit the utility model to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the utility model, so that technicians in the relevant technical field can well understand and use the utility model. The utility model is limited only by the claims and their full scope and equivalents.

Claims

1. An adjustable neck support suitable for a dental chair, fixed on two support rods (1) of the dental chair, comprising a mounting box (2) and two groups of clamping blocks for clamping the two support rods (1), each group of clamping blocks comprising an inner clamping block (3) and an outer clamping block (4) arranged opposite to each other, characterized in that: The support rod (1), the inner clamping block (3) and the outer clamping block (4) are all symmetrically arranged. The installation box (2) is provided with an inner clamping mechanism (5) fixedly connected to the inner clamping block (3) and an outer clamping mechanism (6) fixedly connected to the outer clamping block (4). The inner clamping mechanism (5) and the outer clamping mechanism (6) can respectively drive the inner clamping block (3) and the outer clamping block (4) to move in a direction of approaching or moving away from each other. The outer side of the installation box (2) is provided with an angle adjustment mechanism (7). The end of the angle adjustment mechanism (7) away from the installation box (2) is fixedly connected to a neck support plate (8).

2. The adjustable neck support for a dental chair according to claim 1, characterized in that: The inner clamping mechanism (5) comprises a rotating column (501) located inside the installation box (2), a gear (502), two racks (503), and a control member 1 extending to the outside of the installation box (2) and penetrating the installation box (2) and fixedly connected to the rotating column (501); the rotating column (501) penetrates the gear (502) and is fixedly connected to the gear (502); the gear (502) is located between the two racks (503) and is respectively meshed with the two racks (503); the two racks (503) are respectively connected to one of the inner clamping blocks (3) via a connecting member passing through the installation box (2); the two racks (503) are symmetrical about the axis of the rotating column (501) as the origin; and the gear (502) is movably connected to the inside of the installation box (2) via the rotating column (501).

3. The adjustable neck support for a dental chair according to claim 2, characterized in that: The control member 1 comprises a cross block (504) and a knob 1 (505); the rotary column (501) is provided with a connection hole matched with the cross block (504); the cross block (504) is plugged into and matched with the connection hole of the rotary column (501); the knob 1 (505) is located outside the installation box (2); the bottom end of the knob 1 (505) passes through the installation box (2) and is fixedly connected to the cross block (504); a thread is provided on the outer periphery of the knob 1 (505) adjacent to the bottom end thereof, and the knob 1 (505) is threadedly connected to the installation box (2).

4. The adjustable neck support for a dental chair according to claim 3, characterized in that: The connecting member comprises a group of symmetrical moving bars (9) fixedly connected to the bottom end of the inner clamping block (3); one end of the moving bar (9) away from the inner clamping block (3) passes through the mounting box (2) and is fixedly connected to the rack (503).

5. The adjustable neck support for a dental chair according to claim 1, characterized in that: The external clamping mechanism (6) comprises two symmetrically arranged moving blocks (601), an adjusting rod (602) and two knobs (603) located outside the installation box (2); the two ends of the adjusting rod (602) respectively pass through the installation box (2) and are fixedly connected to the knobs (603); the installation box (2) and the adjusting rod (602) are movably connected; a group of symmetrical threads are provided on the outside of the adjusting rod (602); the moving block (601) passes through the installation box (2), and one end of the moving block (601) extends to the outside of the installation box (2) and is fixedly connected to the external clamping block (4); the moving block (601) is located inside the installation box (2) adjacent to the other end thereof and is threadedly connected to the adjusting rod (602).

6. The adjustable neck support for a dental chair according to claim 1, characterized in that: The angle adjustment mechanism (7) comprises a pair of teeth (701), a pair of teeth (702), a control rod (703), a support block (704), a rotary rod (705) and a knob (706); the pair of teeth (701) is fixedly connected to one end of the control rod (703), and the knob (706) is fixedly connected to the other end of the control rod (703); the pair of teeth (701) is meshed with the pair of teeth (702); the support block (704) and the rotary rod (705) form a group and two groups are provided in total, and each group of support blocks (704) is symmetrically arranged; one end of the rotary rod (705) passes through the support block (704), and the rotary rod (705) is movably connected to the support block (704); and the other end of the rotary rod (705) is movably connected to the inside of the support block (704).

7. The adjustable neck support for a dental chair according to claim 6, characterized in that: The angle adjustment mechanism (7) also includes a reset spring (707) and a spacer ring (708), and the spacer ring (708) and the reset spring (707) can be sleeved on the outer side of the control rod (703), one end of the reset spring (707) is fixedly connected to the support block (704), and the other end of the reset spring (707) is fixedly connected to one side of the spacer ring (708), the other side of the spacer ring (708) is in contact with the back side of the first tooth (701), and the second tooth (702) is fixedly connected to one side of the support block (704), the control rod (703) passes through the rotary rod (705), and the control rod (703) is movably connected to the rotary rod (705), and the outer side of the rotary rod (705) is fixedly connected with a group of symmetrical connecting plates (10), and the other end of the connecting plates (10) is fixedly connected to the back side of the neck support plate (8).

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