Novel posterior atlantoaxial reduction forceps

Abstract

The utility model provides a novel posterior atlantoaxial reset forceps, include: first handle, be connected with first adjusting handle on first handle, be connected with first anchoring structure on first adjusting handle, first anchoring structure locks atlantoaxyphoid screw; Second handle, be connected with second adjusting handle on second handle, be connected with second anchoring structure on second adjusting handle, second anchoring structure locks pivot screw; The middle part of first handle and second handle is hinged; First anchoring structure and second anchoring structure are crossed and lock up connecting rod. The utility model is based on the basis that internal fixation is inserted into atlantoaxial screw and pivot screw, and pivot screw is locked through second adjusting handle operation, and the connecting rod that anchors and pivot screw is attached, makes screw, connecting rod and pivot fixed as a whole, as the fulcrum of reset; Then through first adjusting handle can pull atlantoaxyphoid screw, is applicable to the reset operation mode of internal fixation and is inserted into pedicle screw, can pass through first adjusting handle accurate control posterior reset tension to satisfaction.

Description

Technical Field

[0001] This utility model relates to the field of surgical instruments for cervical spine diseases, and in particular to a novel posterior atlantoaxial repositioning clamp. Background Technology

[0002] The upper cervical spine, including the atlas and axis, forms a complex joint system, the most mobile joint in the spine. Upper cervical spine disorders include odontoid malformation, flat skull base, atlanto-occipital fusion, cervical segmentation insufficiency (Klippel-Feil syndrome), basilar impression, and atlantoaxial dislocation. These conditions can occur individually or simultaneously. Mild cases generally have no obvious clinical symptoms, while severe cases can cause compression of the upper cervical spinal cord, leading to quadriplegia or even respiratory muscle paralysis, which can be life-threatening. Severe cases often require surgical treatment to relieve spinal cord compression, stabilize spinal segments, and prevent secondary damage.

[0003] Common surgical approaches include anterior, posterior, and combined approaches. Compared to anterior surgery, posterior surgery involves only one incision and is more maneuverable, effectively reducing perioperative discomfort and surgical complications. The key to posterior surgery is the placement of internal fixation devices and effective atlantoaxial reduction. Posterior internal fixation methods include pedicle screws, lateral mass screws, and laminectomy screws; currently, different screw combinations can achieve internal fixation. However, the degree of reduction lacks clear guidance. The diversity of screw placement methods and the instability of reduction traction forces pose challenges to atlantoaxial reduction, often resulting in unsatisfactory postoperative outcomes.

[0004] In existing patented technologies, such as the Chinese invention patent application with publication number CN109247979A and publication date of January 22, 2019, the atlas and axis are fixed by two arms respectively, and then the atlas is lifted to achieve atlantoaxial repositioning.

[0005] However, this type of patented technology directly uses a hook to pull and reduce the posterior arch of the atlas, without a structure connecting the atlas screw, and is not suitable for the reduction operation of internal fixation with pedicle screws. Utility Model Content

[0006] The purpose of this utility model is to provide a novel posterior atlantoaxial reduction clamp that can precisely control the posterior reduction tension based on the internal fixation of atlantoaxial screws and axis screws.

[0007] This utility model provides a novel posterior atlantoaxial reduction clamp, comprising: a first clamp handle, on which a first adjusting handle is connected, and on which a first anchoring structure is connected, wherein the first anchoring structure locks an atlantoaxial screw; a second clamp handle, on which a second adjusting handle is connected, and on which a second anchoring structure is connected, wherein the second anchoring structure locks an atlantoaxial screw; the first clamp handle and the second clamp handle are hinged at their middle portions; a connecting rod passes through and is locked in the first anchoring structure and the second anchoring structure.

[0008] Furthermore, the first adjusting handle includes a first outer sleeve and a first inner sleeve, the first outer sleeve is connected to the first clamp handle, the first inner sleeve is retractably connected inside the first outer sleeve, and the first anchoring structure is connected to the front end of the first inner sleeve.

[0009] Furthermore, the first adjusting handle also includes a locking sleeve, which is movably sleeved outside the first inner sleeve; the front end of the first inner sleeve has a slit, the first anchoring structure is clamped between the slits, and the locking sleeve tightens the slit by moving closer to the front end of the first inner sleeve.

[0010] Furthermore, the second adjusting handle includes a second outer sleeve and an inner adjusting handle. The second outer sleeve is connected to the second clamp handle, and the inner adjusting handle is retractably connected inside the second outer sleeve. The second anchoring structure is connected to the front end of the inner adjusting handle.

[0011] Furthermore, the first inner sleeve is provided with an external thread, the first outer sleeve is provided with an internal thread, and the first inner sleeve and the first outer sleeve are threadedly connected; the inner adjusting handle is provided with an external thread, the second outer sleeve is provided with an internal thread, and the inner adjusting handle and the second outer sleeve are threadedly connected.

[0012] Furthermore, the outer wall of the first inner sleeve is provided with a stop groove along the axial direction, and the first outer sleeve is provided with a stop hole along the radial direction. A stop pin can be detachably inserted into the stop hole and embedded in the stop groove.

[0013] Furthermore, the front end of the second outer sleeve is provided with a hook, which is hooked onto the connecting rod.

[0014] Furthermore, the first anchoring structure and the second anchoring structure each include a connector and a stop block. The connector is hollow inside, and the end of the screw passes through it axially and is embedded in the connector. The connecting rod passes through the two connectors radially, and the connecting rod abuts against the end of the screw through the stop block.

[0015] Furthermore, the first anchoring structure further includes a first locking member, and the second anchoring structure further includes a second locking member. A locking structure is provided on the inner wall of the connector. The first locking member passes through the inside of the first inner sleeve and locks with the locking structure inside the connector of the first anchoring structure. The second locking member is connected to the front end of the inner adjusting handle and locks with the locking structure inside the connector of the second anchoring structure.

[0016] Furthermore, an opening adjustment mechanism is provided between the first clamp handle and the second clamp handle. The opening adjustment mechanism includes a rotating arm and an elastic support member. The rotating arm is rotatably connected to the first clamp handle and has a limiting structure. The elastic support member is connected between the first clamp handle and the second clamp handle, and the second clamp handle abuts against the limiting structure on the rotating arm.

[0017] The technical solution of this utility model, based on the internal fixation of atlantoaxial screws and axis screws, uses a second adjusting handle to lock the axis screw and anchor the connecting rod attached to the axis screw, fixing the screw, connecting rod, and axis into one unit, serving as a fulcrum for reduction; then, the atlantoaxial screw can be pulled up by the first adjusting handle, which is suitable for the reduction operation of internal fixation pedicle screws. The first adjusting handle can precisely control the posterior reduction traction force to a satisfactory level, thereby improving the effectiveness of atlantoaxial reduction surgery and reducing surgical risks and the possibility of postoperative complications. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0020] Figure 2 This utility model Figure 1 Enlarged view of point A;

[0021] Figure 3 This is a side view of the present invention;

[0022] Figure 4 This utility model Figure 3 AA section view;

[0023] Figure 5 This is a schematic diagram of the connector after the first inner sleeve is hidden in this utility model;

[0024] Figure 6This is a schematic diagram of the abutment block behind the concealed connector of this utility model;

[0025] Explanation of reference numerals in the attached figures:

[0026] 1-First clamp handle; 2-First adjusting handle; 21-First outer sleeve; 211-Stop hole; 22-First inner sleeve; 221-Crack; 222-Stop groove; 23-Locking sleeve; 24-Stop pin; 3-First anchoring structure; 4-Atlantic screw;

[0027] 5-Second clamp handle; 6-Second adjusting handle; 61-Second outer sleeve; 611-Hook; 62-Inner adjusting handle; 7-Second anchoring structure; 8-Pivot screw;

[0028] 9-Linkage rod; 10-Connector; 1001-Locking structure; 11-Abutment block; 12-Rotating arm; 13-Elastic support; 14-Limiting structure. Detailed Implementation

[0029] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0030] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] Example 1

[0033] like Figures 1-6 As shown, this utility model provides a novel posterior atlantoaxial reduction clamp, comprising: a first clamp handle 1, a first adjusting handle 2 connected to the first clamp handle 1, a first anchoring structure 3 connected to the first adjusting handle 2, and the first anchoring structure 3 locking an atlantoaxial screw 4; a second clamp handle 5, a second adjusting handle 6 connected to the second clamp handle 5, a second anchoring structure 7 connected to the second adjusting handle 6, and the second anchoring structure 7 locking an atlantoaxial screw 8; the first clamp handle 1 and the second clamp handle 5 are hinged at their middle parts; a connecting rod 9 passes through and is locked in the first anchoring structure 3 and the second anchoring structure 7.

[0034] Specifically, the first clamp handle 1 and the second clamp handle 5 are hinged at the middle to form a scissor structure. The first anchoring structure 3 and the atlas screw 4 are adjusted by the first adjusting handle 2, thereby gradually pulling the anteriorly dislocated atlas back to its original position, thus applying a repositioning force to the atlantoaxial joint. The axis screw 8 is locked by operating the second adjusting handle 6, anchoring the connecting rod 9 (specifically a titanium rod) attached to the axis screw 8, thus fixing the screw, titanium rod, and axis into a single unit, serving as a fulcrum for repositioning.

[0035] This invention can be applied to atlantoaxial reduction surgery to treat spinal cord compression symptoms caused by atlantoaxial dislocation due to various reasons (basal skull impression, spontaneous atlantoaxial dislocation, etc.). By increasing the posterior reduction force based on the existing internal fixation screw placement, effective atlantoaxial reduction can be achieved, thereby improving surgical effectiveness and reducing surgical risks and postoperative complications.

[0036] Example 2

[0037] The first adjusting handle 2 includes a first outer sleeve 21 and a first inner sleeve 22. The first outer sleeve 21 is connected to the first clamp handle 1. The first inner sleeve 22 is telescopically connected inside the first outer sleeve 21. The first anchoring structure 3 is connected to the front end of the first inner sleeve 22. The first adjusting handle 2 also includes a locking sleeve 23, which is movably sleeved outside the first inner sleeve 22. The front end of the first inner sleeve 22 has a slit 221. The first anchoring structure 3 is clamped between the slits 221. The locking sleeve 23 tightens the slit 221 by moving closer to the front end of the first inner sleeve 22. The first inner sleeve 22 is provided with an external thread, and the first outer sleeve 21 is provided with an internal thread. The first inner sleeve 22 and the first outer sleeve 21 are threadedly connected. The outer wall of the first inner sleeve 22 is provided with a stop groove 222 along the axial direction, and the first outer sleeve 21 is provided with a stop hole 211 along the radial direction. A stop pin 24 can be detachably inserted into the stop hole 211 and embedded in the stop groove 222.

[0038] Specifically, the first outer sleeve 21 is connected and fixed to the first clamp handle 1. The first inner sleeve 22 is threaded inside the first outer sleeve 21. By turning the first inner sleeve 22, the telescopic movement of the first inner sleeve 22 relative to the first outer sleeve 21 can be adjusted. The rear end of the first inner sleeve 22 extends out of the first outer sleeve 21 and is fixedly connected to a handle with friction grooves for easy turning. Through the telescopic movement of the first inner sleeve 22, the first anchoring structure 3 connected to it can be lifted, thereby lifting the atlas screw 4 anchored to the first anchoring structure 3, and thus lifting the atlas to achieve atlas repositioning. When the atlas is lifted to the appropriate position, it needs to be fixed in this position. At this time, the stop pin 24 is passed through the stop hole 211 on the first outer sleeve 21 and embedded in the stop groove 222 on the first inner sleeve 22, thereby limiting the rotation of the first inner sleeve 22, that is, restricting the telescopic movement of the first inner sleeve 22, thus fixing the position of the atlas.

[0039] The first inner sleeve 22 is hollow inside, and its front end (the end used to connect to the first anchoring structure 3) is split along the diameter to form a slit 221. The first anchoring structure 3 is clamped in the slit 221. By opening or closing the slit 221, the first anchoring structure 3 can be released or clamped, achieving a detachable connection. The opening and closing of the slit 221 is controlled by the locking sleeve 23. When the locking sleeve 23 moves towards the first anchoring structure 3, it gradually tightens and closes the slit 221. Conversely, when the locking sleeve 23 moves away from the first anchoring structure 3, it allows the slit 221 to open freely. The movement of the locking sleeve 23 is achieved through a threaded connection with the first inner sleeve 22, that is, by rotating the locking sleeve 23, it moves axially on the first inner sleeve 22.

[0040] Example 3

[0041] The second adjusting handle 6 includes a second outer sleeve 61 and an inner adjusting handle 62. The second outer sleeve 61 is connected to the second clamp handle 5. The inner adjusting handle 62 is retractably connected inside the second outer sleeve 61. The second anchoring structure 7 is connected to the front end of the inner adjusting handle 62. The inner adjusting handle 62 has external threads, and the second outer sleeve 61 has internal threads. The inner adjusting handle 62 and the second outer sleeve 61 are threaded together. The front end of the second outer sleeve 61 has a hook 611, which hooks onto the connecting rod 9.

[0042] Specifically, the second anchoring structure 7 anchors the pivot screw 8 and serves as a repositioning fulcrum. The pivot screw 8, connecting rod 9, and locking element are locked before repositioning. The second outer sleeve 61 is connected and fixed to the second clamp handle 5. The inner adjusting handle 62 is threaded into the second outer sleeve 61. By turning the inner adjusting handle 62, the telescopic movement of the inner adjusting handle 62 relative to the second outer sleeve 61 can be adjusted. The rear end of the inner adjusting handle 62 extends out of the second outer sleeve 61 and is fixedly connected to a handle with friction grooves for easy turning.

[0043] By extending and retracting the inner adjusting handle 62, the second locking member connected to its end can be locked or released from the locking structure 1001 in the connector 10 of the second anchoring structure 7, thereby locking and releasing the connecting rod 9 and the pivot screw 8.

[0044] The second outer sleeve 61 has two hooks 611 at its front end. Both hooks 611 are hooked onto the connecting rod 9, and the second anchoring structure 7 (connector 10) is located between the two hooks 611, so as to realize the quick and convenient connection between the second outer sleeve 61 and the connecting rod 9. When the opening of the two clamps changes, the two hooks 611 can keep the position of the second anchoring structure 7 changing synchronously.

[0045] Example 4

[0046] The first anchoring structure 3 and the second anchoring structure 7 each include a connector 10 and a stop block 11. The connector 10 is hollow inside, and the end of the screw passes through it axially and is embedded inside the connector 10. The connecting rod 9 passes through the two connectors 10 radially and abuts against the end of the screw through the stop block 11. The first anchoring structure 3 also includes a first locking member (not shown), and the second anchoring structure 7 also includes a second locking member (not shown). A locking structure 1001 is provided on the inner wall of the connector 10. The first locking member passes through the inside of the first inner sleeve 22 and locks with the locking structure 1001 inside the connector 10 of the first anchoring structure 3. The second locking member is connected to the front end of the inner adjusting handle 62 and locks with the locking structure 1001 inside the connector 10 of the second anchoring structure 7.

[0047] Specifically, the connector 10 has a U-shaped structure for the connecting rod 9 to pass through the U-shaped opening, and the end has a through hole for the atlas screw 4 and pivot screw 8 to pass through and be embedded. The screw end (end cap) has an enlarged structure so that it cannot be detached from the connector 10. To prevent the screw from moving axially within the connector 10, a stop block 11 is used to hold the screw end within the connector 10, and then the connecting rod 9 presses against the stop block 11, thereby pressing and fixing the screw. The front end of the stop block 11 is a convex curved surface to fit the curved inner wall of the connector 10, and the rear end of the stop block 11 is a (semi-circular) groove to fit the (rod-shaped) outer wall of the connecting rod 9.

[0048] The first inner sleeve 22 is hollow, so the first locking member can be inserted through the rear port of the first inner sleeve 22 and fall into the locking structure 1001 at the rear end of the connector 10 along the inside of the first inner sleeve 22. The first locking member is then locked to the locking structure 1001 by operating a tool from inside the first inner sleeve 22. Specifically, for example, the first locking member (and the second locking member) is a screw or bolt, and the locking structure 1001 is an internal thread on the inner wall of the connector 10. After the bolt is inserted, the screwdriver is used to tighten the internal thread of the bolt through the first inner sleeve 22, so that the connecting rod 9 is pressed.

[0049] The first inner sleeve 22 has two slits 221 at the front end, each with an insertion hole. The connector 10 is externally fixed with a short rod. The connector 10 is clamped inside the slit 221 and the short rod is inserted into the insertion hole. The connector 10 is then clamped by tightening the slit 221 with the locking sleeve 23.

[0050] Example 5

[0051] An opening adjustment mechanism is provided between the first clamp handle 1 and the second clamp handle 5. The opening adjustment mechanism includes a rotating arm 12 and an elastic support member 13. The rotating arm 12 is rotatably connected to the first clamp handle 1. A limiting structure 14 is provided on the rotating arm 12. The elastic support member 13 is connected between the first clamp handle 1 and the second clamp handle 5. The second clamp handle 5 abuts against the limiting structure 14 on the rotating arm 12.

[0052] Specifically, the opening widens when the second clamp handle 5 moves away from the first clamp handle 1, and conversely, the opening narrows when the second clamp handle 5 moves closer to the first clamp handle 1. The vertical spacing between the atlantoaxial screw 4 and the pivot screw 8 is adjusted accordingly to restore the atlantoaxial alignment. The elastic support 13 can be a spring or a spring plate, etc., used to maintain the opening with minimal effort. The rotating connection between the rotating arm 12 and the first clamp handle 1 is equipped with a structure such as a locking nut to control the angle of the rotating arm 12. The limiting structure 14 on the rotating arm 12 can be multiple serrated stops. During operation, first loosen the locking structure 1001 between the rotating arm 12 and the first clamp handle 1, allowing the second clamp handle 5 to move (relatively). When the opening is adjusted appropriately and the reset is satisfactory, rotate the rotating arm 12 to contact the end of the second clamp handle 5, and the end of the second clamp handle 5 is blocked and limited by the serrated stops. Tighten the locking structure 1001 between the rotating arm 12 and the first clamp handle 1 to automatically maintain the opening position of the clamp handle.

[0053] How this utility model is used:

[0054] The atlas is connected by an atlas screw 4, and the axis is connected by an axis screw 8. When the inner adjusting handle 62 is turned, the second locking element (bolt) is locked to the locking structure 1001 (internal thread) of the connector 10. The hook 611 at the front end of the second outer sleeve 61 hooks onto the connecting rod 9 and both sides of the connector 10, thereby locking the axis screw 8 and serving as a reset fulcrum. When the locking sleeve 23 is turned, it moves forward to clamp the front end slit 221 of the first inner sleeve 22, thus clamping the connector 10 of the first anchoring structure 3. When the first inner sleeve 22 is turned, the atlas screw 4 is pulled up to reset the atlas that has slipped forward. Once the reset is satisfactory, the rotating arm 12 is rotated to contact the end of the second clamp handle 5. The end of the second clamp handle 5 is stopped and limited by a serrated stop bar. Tightening the locking structure 1001 between the rotating arm 12 and the first clamp handle 1 will automatically maintain the opening position of the clamp handle.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A novel posterior atlantoaxial reduction clamp, characterized in that, include: A first clamp handle, a first adjusting handle connected to the first clamp handle, a first anchoring structure connected to the first adjusting handle, and the first anchoring structure locking the atlantoaxial screw. A second clamp handle, a second adjusting handle connected to the second clamp handle, a second anchoring structure connected to the second adjusting handle, and the second anchoring structure locking the pivot screw; The first clamp handle and the second clamp handle are hinged at the middle; A connecting rod passes through and locks into both the first and second anchoring structures.

2. The novel posterior atlantoaxial reduction clamp according to claim 1, characterized in that, The first adjusting handle includes a first outer sleeve and a first inner sleeve. The first outer sleeve is connected to the first clamp handle, and the first inner sleeve is retractably connected inside the first outer sleeve. The first anchoring structure is connected to the front end of the first inner sleeve.

3. The novel posterior atlantoaxial reduction clamp according to claim 2, characterized in that, The first adjusting handle also includes a locking sleeve, which is movably sleeved outside the first inner sleeve; the front end of the first inner sleeve has a slit, the first anchoring structure is clamped between the slits, and the locking sleeve tightens the slit by moving closer to the front end of the first inner sleeve.

4. The novel posterior atlantoaxial reduction clamp according to claim 2, characterized in that, The second adjusting handle includes a second outer tube and an inner adjusting handle. The second outer tube is connected to the second clamp handle. The inner adjusting handle is retractably connected inside the second outer tube. The second anchoring structure is connected to the front end of the inner adjusting handle.

5. The novel posterior atlantoaxial reduction clamp according to claim 4, characterized in that, The first inner sleeve is provided with an external thread, the first outer sleeve is provided with an internal thread, and the first inner sleeve and the first outer sleeve are threadedly connected. The inner adjusting handle is provided with an external thread, and the second outer sleeve is provided with an internal thread. The inner adjusting handle and the second outer sleeve are threadedly connected.

6. The novel posterior atlantoaxial reduction clamp according to claim 5, characterized in that, The outer wall of the first inner sleeve is provided with a stop groove along the axial direction, and the first outer sleeve is provided with a stop hole along the radial direction. A stop pin can be detachably inserted into the stop hole and embedded in the stop groove.

7. The novel posterior atlantoaxial reduction clamp according to claim 4, characterized in that, The front end of the second outer tube is provided with a hook, which is hooked onto the connecting rod.

8. The novel posterior atlantoaxial reduction clamp according to claim 4, characterized in that, The first anchoring structure and the second anchoring structure each include a connector and a stop block. The connector is hollow inside, and the end of the screw passes through it axially and is embedded in the connector. The connecting rod passes through the two connectors radially, and the connecting rod abuts against the end of the screw through the stop block.

9. The novel posterior atlantoaxial reduction clamp according to claim 8, characterized in that, The first anchoring structure further includes a first locking element, the second anchoring structure further includes a second locking element, and the inner wall of the connector is provided with a locking structure; The first locking member passes through the inside of the first inner sleeve and locks itself with the locking structure inside the connector of the first anchoring structure. The second locking member is connected to the locking structure inside the connector of the inner adjusting handle and the second anchoring structure and locked in place.

10. The novel posterior atlantoaxial reduction clamp according to claim 1, characterized in that, An opening adjustment mechanism is provided between the first clamp handle and the second clamp handle. The opening adjustment mechanism includes a rotating arm and an elastic support member. The rotating arm is rotatably connected to the first clamp handle and has a limiting structure. The elastic support member is connected between the first clamp handle and the second clamp handle, and the second clamp handle abuts against the limiting structure on the rotating arm.

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