Universal wide-angle screw and assembling method thereof

Abstract

The invention provides a universal large-angle screw and an assembling method thereof, and relates to the technical field of medical instruments. The universal large-angle screw comprises a screw base, a pressing ring, an intermediate ring and a screw tail. The intermediary ring is provided with an opening axially penetrating through the intermediary ring, one axial end of the intermediary ring is clamped and matched with the nail seat, and the other axial end of the intermediary ring is provided with a notch communicated with the opening; and a ball head is arranged at one end of the nail tail, is clamped and matched in the intermediate ring, and can realize the tilting action of the nail tail. The nail tail can tilt around the ball head relative to the nail seat and can tilt into the notch so as to obtain a larger tilting angle; the ball head of the nail tail is stably limited in the intermediary ring, friction force exists between the ball head and the intermediary ring, the nail tail can rotate by 360 degrees along with the intermediary ring, and after the nail tail is implanted into a human body, the intermediary ring can be kept stable at any position by means of the friction force between the ball head and the intermediary ring, namely self-parking is achieved, and meanwhile the large-angle flexible tilting and universal functions of the nail tail are achieved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a universal large-angle screw and its assembly method. Background Technology

[0002] Universal screws mainly consist of a base and a swivelly connected to the base. The swivelly end of the swivelly engages with the inner cavity of the base, allowing it to tilt within a certain range relative to the base. However, to achieve a wider tilting angle range, existing structures typically require enlarging the opening at the bottom of the base, which may lead to reduced stability of the ball joint connection. Furthermore, for smooth tilting movement of the swivelly end, the ball joint and the inner cavity of the base must maintain an appropriate clearance. Traditional assembly processes often struggle to simultaneously meet the dual technical requirements of ensuring the ball joint's rotational flexibility and maintaining its positional stability. Summary of the Invention

[0003] The purpose of this invention is to provide a universal large-angle screw and its assembly method to meet the dual technical requirements of flexible tilting of the screw tail at a large angle and stable assembly position of the ball head.

[0004] In a first aspect, the universal large-angle screw provided by the present invention includes: a screw base, a pressure ring, an intermediate ring, and a screw tail; the side wall of the intermediate ring is provided with an opening that penetrates the intermediate ring axially, one axial end of the intermediate ring is engaged with the screw base, and the other axial end of the intermediate ring is provided with a groove extending from the inside to the outside and communicating with the opening; one end of the screw tail is provided with a ball head, and the screw tail passes through the screw base and the intermediate ring, the pressure ring is installed in the screw base, and the ball head is movably engaged in the intermediate ring and clamped by the intermediate ring.

[0005] Optionally, the slot includes an arcuate groove adapted to the nail tail; the axis of the arcuate groove is inclined from one end near the nail seat to the other end away from the nail seat in a direction away from the axis of the intermediate ring.

[0006] Optionally, the intermediate ring has an inner ball groove that is adapted to the ball head.

[0007] Optionally, the cross-sectional diameter of the middle part of the inner ball groove along the axial direction of the intermediate ring is larger than the cross-sectional diameter of the two ends of the inner ball groove.

[0008] Optionally, the sidewall of the intermediate ring is provided with a stiffness weakening groove, and the stiffness weakening groove and the opening are spaced apart along the circumference of the intermediate ring.

[0009] Optionally, the outer side wall of the intermediate ring is provided with a first convex ring and a second convex ring; the first convex ring and the second convex ring are spaced apart along the axial direction of the intermediate ring, and an outer ring groove is formed between the first convex ring and the second convex ring; the pin seat is engaged with the first convex ring and the outer ring groove, and the intermediate ring is rotatably engaged with the pin seat.

[0010] Optionally, the nail seat is provided with an intermediate ring groove adapted to the first convex ring and a pressure ring groove adapted to the pressure ring; the inner wall of the pressure ring groove is provided with a first limiting boss adapted to the pressure ring.

[0011] Optionally, the outer side wall of the pressure ring is provided with a second limiting boss corresponding to the first limiting boss; the end face of the first limiting boss is away from the pressure ring groove, and / or, the end face of the second limiting boss near the intermediate ring groove is provided with an inclined surface that slopes from the outside to the inside towards the intermediate ring groove.

[0012] Optionally, the pressure ring has a circumferential limiting groove at one end away from the nail tail; the nail seat has a radially penetrating notch, and a connecting rod adapted to the circumferential limiting groove is detachably installed in the notch; the nail seat can be detachably fitted with a screw plug, and the connecting rod is pressed between the screw plug and the pressure ring.

[0013] Secondly, the universal large-angle screw assembly method provided by the present invention includes: One end of the intermediate ring is snapped into the nail seat, and the other end of the intermediate ring is provided with a groove extending from the inside to the outside, the groove communicating with an opening that penetrates the side wall of the intermediate ring along the axis. The nail tail is passed through the nail seat and the intermediate ring, so that the ball head at one end of the nail tail is pressed into the intermediate ring; wherein the intermediate ring expands radially within the nail seat and presses the ball head radially.

[0014] The embodiments of the present invention bring the following beneficial effects: The sidewall of the intermediate ring is provided with an opening that penetrates the intermediate ring along the axial direction. One axial end of the intermediate ring is engaged with the nail seat, and the other axial end of the intermediate ring is provided with a groove that extends from the inside to the outside and connects to the opening. One end of the nail tail is provided with a ball head. By passing the nail tail through the nail seat and the intermediate ring, and installing the pressure ring on the nail seat, the ball head can be movably engaged between the pressure ring and the intermediate ring. On the one hand, the nail tail can tilt around the ball head relative to the nail seat, and can tilt into the groove to obtain a larger tilting angle. On the other hand, the ball head is stably restricted in the intermediate ring, and there is friction between the ball head and the intermediate ring. The nail tail can rotate with the intermediate ring, and the ball head remains stable and self-retaining relative to the intermediate ring, thus realizing the large-angle flexible tilting and universal function of the nail tail.

[0015] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a cross-sectional view of a universal high-angle screw provided in an embodiment of the present invention; Figure 2 A schematic diagram of a universal large-angle screw provided in an embodiment of the present invention; Figure 3 An exploded view of a universal large-angle screw provided in an embodiment of the present invention; Figure 4 A top view of the intermediate ring of a universal large-angle screw provided in an embodiment of the present invention; Figure 5 A schematic diagram of the intermediate ring of a universal large-angle screw provided in an embodiment of the present invention; Figure 6 A cross-sectional view of the intermediate ring of a universal large-angle screw provided in an embodiment of the present invention; Figure 7 A cross-sectional view of the screw base of a universal large-angle screw provided in an embodiment of the present invention; Figure 8 A cross-sectional view of the pressure ring of a universal large-angle screw provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the pressure ring of a universal large-angle screw provided in an embodiment of the present invention.

[0018] Icons: 100-Nail seat; 101-Plug; 102-Connecting rod; 103-Threaded section; 104-Side hole; 105-Intermediate ring groove; 106-Pressure ring groove; 107-First limiting boss; 200-Pressure ring; 201-Circumferential limiting groove; 202-Second limiting boss; 203-Conical groove; 300-Intermediate ring; 301-First convex ring; 302-Second convex ring; 303-Inner ball groove; 304-Outer ring groove; 305-Inner conical surface; 306-Opening; 307-Stiffness weakening groove; 308-Groove opening; 400-Nail tail; 401-Ball head; 402-Rod section; 403-Nail tail threaded section. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used only to describe differences in name and should not be construed as indicating or implying relative importance. Physical quantities in formulas, unless otherwise specified, should be understood as basic quantities in the International System of Units (SI), or derived quantities derived from basic quantities through mathematical operations such as multiplication, division, differentiation, or integration.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; and 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 invention based on the specific circumstances.

[0022] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the universal large-angle screw provided in this embodiment of the invention includes: a screw base 100, a pressure ring 200, an intermediate ring 300, and a screw tail 400; the side wall of the intermediate ring 300 is provided with an opening 306 that passes through the intermediate ring 300 along the axial direction, one axial end of the intermediate ring 300 is engaged with the screw base 100, and the other axial end of the intermediate ring 300 is provided with a groove 308 that extends from the inside to the outside and connects to the opening 306; one end of the screw tail 400 is provided with a ball head 401, and the screw tail 400 passes through the screw base 100 and the intermediate ring 300, the pressure ring 200 is installed in the screw base 100, and the ball head 401 is movably engaged in the intermediate ring 300 and clamped by the intermediate ring 300, so that when the screw tail 400 tilts relative to the intermediate ring 300, there is frictional resistance between the ball head 401 and the intermediate ring 300, and the tilted screw tail 400 can be kept at a stable angle by static friction.

[0023] During assembly, the intermediate ring 300 can be radially compressed, reducing the width of the opening 306 to allow it to be inserted into the bottom of the nail holder 100. After releasing the intermediate ring 300, it springs back radially, opening 306 and thus engaging with the nail holder 100. The ball head 401 is positioned between the pressure ring 200 and the intermediate ring 300. The nail tail 400 can rotate around the axis of the intermediate ring 300 via the ball head 401 and can also tilt relative to the axis of the intermediate ring 300 within the opening range. When a larger tilt angle is required, the nail tail 400 can tilt into the slot 308, at which point the tilt angle is at its maximum, easily achieving an angle greater than or equal to 45 degrees between the nail tail 400 and the axis of the nail holder 100, while maintaining the stability of the ball head 401.

[0024] It should be noted that the ball head 401 is pressed tightly inside the intermediate ring 300, and there is friction between the ball head 401 and the intermediate ring 300. While ensuring that the nail tail 400 can tilt around the center of the ball head 401 relative to the intermediate ring 300, the nail tail 400 can also rotate with the intermediate ring 300 relative to the nail seat 100 around its axis, thereby changing the orientation of the tip of the nail tail 400, realizing the universal adjustment function, and can achieve self-locking by using static friction after adjustment.

[0025] In this embodiment of the invention, the slot 308 includes an arcuate groove adapted to the nail tail 400; the axis of the arcuate groove is inclined from one end near the nail seat 100 to the end away from the nail seat 100 in a direction away from the axis of the intermediate ring 300.

[0026] The included angle between the axis of the arc groove and the axis of the intermediate ring 300 is greater than or equal to 45 degrees. The nail tail 400 includes a ball head 401, a rod segment 402 and a nail tail threaded segment 403 connected in sequence. When the nail tail 400 is tilted to the maximum angle, the rod segment 402 can fit against the inner wall of the arc groove.

[0027] Furthermore, the intermediate ring 300 has an inner ball groove 303 that is adapted to the ball head 401. The ball head 401 fits in the inner ball groove 303, and the center of the ball head 401 coincides with the center of the ball groove 303, thereby ensuring the stability of the position of the ball head 401.

[0028] Furthermore, the cross-sectional diameter of the middle part of the inner ball groove 303 along the axial direction of the intermediate ring 300 is larger than the cross-sectional diameter of both ends of the inner ball groove 303. During initial installation, the rod segment 402 and the threaded segment 403 of the nail end pass through the nail seat 100 and the intermediate ring 300, and the ball head 401, with a diameter slightly larger than the top cross-sectional diameter of the inner ball groove 303, abuts against the top of the intermediate ring 300. When installing the pressure ring 200, other tools can be used to press the ball head 401 into the inner ball groove 303, or the pressure ring 200 can be used to press the ball head 401 downward, thereby pressing the ball head 401 into the inner ball groove 303, thus achieving a spherical contact fit between the ball head 401 and the inner ball groove 303. With the ball head 401 engaged with the inner ball groove 303, the ball head 401 radially expands the intermediate ring 300, thereby ensuring that the intermediate ring 300 is securely engaged with the nail seat 100. In addition, the intermediate ring 300 clamps the ball head 401 radially, and there is sliding friction between the two. When the nail tail 400 tilts relative to the intermediate ring 300 through the ball head 401 to any angle, the tilting angle of the nail tail 400 relative to the intermediate ring 300 can be kept fixed by the friction.

[0029] See Figure 4 The intermediate ring 300 has a stiffness-weakening groove 307 on its sidewall, and the stiffness-weakening groove 307 and the opening 306 are spaced apart along the circumference of the intermediate ring 300. The stiffness-weakening groove 307 can reduce the radial dimension of the sidewall of the intermediate ring 300, making the sidewall at this location easier to bend, and thus facilitating the radial compression of the intermediate ring 300 during assembly. It is particularly suitable to place the stiffness-weakening groove 307 and the opening 306 at opposite positions on the circumference of the intermediate ring 300.

[0030] like Figure 1 , Figure 2 , Figure 3 , Figure 5 , Figure 6 and Figure 7 As shown, the outer side wall of the intermediate ring 300 is provided with a first protruding ring 301 and a second protruding ring 302; the first protruding ring 301 and the second protruding ring 302 are spaced apart along the axial direction of the intermediate ring 300, and an outer ring groove 304 is formed between the first protruding ring 301 and the second protruding ring 302; the nail seat 100 is fitted with the first protruding ring 301 and the outer ring groove 304, and the intermediate ring 300 is rotatably fitted relative to the nail seat 100.

[0031] The outer diameter of the first protruding ring 301 is smaller than that of the second protruding ring 302. When the first protruding ring 301 is fitted into the nail holder 100, the second protruding ring 302 abuts against the bottom of the nail holder 100. The intermediate ring 300 can rotate relative to the nail holder 100. When the nail tail 400 swings into the slot 308 to reach its maximum tilt angle, the orientation of the nail tail 400 can be changed by rotating the intermediate ring 300 relative to the nail holder 100.

[0032] It should be noted that the intermediate ring 300 has an inner conical surface 305 on the inner side of the second convex ring 302 at one end. The nail tail 400 can tilt to fit the inner conical surface 305. At this time, the tilting angle is small. When the nail tail 400 tilts into the groove 308, a larger tilting angle can be obtained.

[0033] See Figure 1 , Figure 5 , Figure 6 , Figure 7 and Figure 8 The nail seat 100 is provided with an intermediate ring groove 105 adapted to the first protruding ring 301 and a pressure ring groove 106 adapted to the pressure ring 200; the inner wall of the pressure ring groove 106 is provided with a first limiting boss 107 adapted to the pressure ring 200.

[0034] The intermediate ring groove 105 has an annular limiting part at one end away from the pressure ring groove 106. When the first convex ring 301 is engaged in the intermediate ring groove 105, the annular limiting part is engaged in the outer ring groove 304, thereby realizing the engagement of the intermediate ring 300 with the nail seat 100, restricting the axial movement of the intermediate ring 300 relative to the nail seat 100, and the intermediate ring 300 can rotate freely relative to the nail seat 100.

[0035] Furthermore, the outer wall of the pressure ring 200 is provided with a second limiting boss 202 corresponding to the first limiting boss 107. The end face of the first limiting boss 107 facing away from the pressure ring groove 106 may have an inclined surface that slopes from the outside inward toward the intermediate ring groove 105; or, the end face of the second limiting boss 202 approaching the intermediate ring groove 105 may have an inclined surface that slopes from the outside inward toward the intermediate ring groove 105. Alternatively, both the end face of the first limiting boss 107 facing away from the pressure ring groove 106 and the end face of the second limiting boss 202 approaching the intermediate ring groove 105 may be configured as inclined surfaces that slope from the outside inward toward the intermediate ring groove 105.

[0036] When the pressure ring 200 is subjected to axial pressure pointing towards the intermediate ring 300, the inclined surface can generate a guiding effect. The force acting on the pressure ring 200 through the inclined surface drives it to compress radially, and the force acting on the nail seat 100 through the inclined surface drives it to expand radially, so that the second limiting boss 202 passes over the first limiting boss 107 until the second limiting boss 202 abuts against the end face of the first limiting boss 107 near the intermediate ring groove 105. This achieves axial positioning of the pressure ring 200 relative to the nail seat 100, ensuring that the ball head 401 can contact and engage with the inner wall of the bottom tapered groove 203 of the pressure ring 200.

[0037] See Figure 3 , Figure 7 , Figure 8 and Figure 9The first limiting boss 107 and the second limiting boss 202 extend circumferentially along the pressure ring 200, and their corresponding extension angles are both less than 180 degrees. The first limiting boss 107 and the second limiting boss 202 can abut or be clearance-fitted. When the first limiting boss 107 and the second limiting boss 202 can abut, the pressure ring 200 can be axially fixed relative to the nail seat 100. When the first limiting boss 107 and the second limiting boss 202 are completely misaligned circumferentially along the pressure ring 200, the pressure ring 200 can slide axially onto the nail seat 100. In an optional embodiment, when it is necessary to disassemble the universal large-angle screw, the pressure ring 200 can be screwed until the second limiting boss 202 and the first limiting boss 107 are completely misaligned. At this time, the axial limiting effect of the first limiting boss 107 on the pressure ring 200 can be released, making it easier to remove the pressure ring 200 from the nail seat 100.

[0038] like Figure 1 , Figure 2 , Figure 3 , Figure 5 , Figure 7 , Figure 8 and Figure 9 As shown, the pressure ring 200 has a circumferential limiting groove 201 at one end away from the nail tail 400; the nail seat 100 has a radially penetrating notch, and a connecting rod 102 adapted to the circumferential limiting groove 201 can be detachably installed in the notch, which can be installed during surgery; the nail seat 100 has a threaded section 103, through which the screw plug 101 can be detachably installed, and during surgery, the connecting rod 102 can be pressed between the screw plug 101 and the pressure ring 200.

[0039] During assembly, after the nail tail 400 is passed through the nail seat 100 and the intermediate ring 300, and the ball head 401 is placed on the intermediate ring 300 for initial alignment, the connecting rod 102 can be inserted from the notch groove, and the circumferential surface of the connecting rod 102 is made to fit against the circumferential limiting groove 201. Subsequently, the screw plug 101 is installed on the threaded section 103 of the nail seat 100 and gradually tightened. The screw plug 101 will compress the connecting rod 102, and the connecting rod 102 will press down on the pressure ring 200. When the second limiting boss 202 passes the first limiting boss 107, the pressure ring 200 is axially positioned relative to the nail seat 100. In addition, the pressure ring 200 will press the ball head 401 into the inner ball groove 303, and use the ball head 401 to radially support the intermediate ring 300, thereby preventing the first convex ring 301 from loosening relative to the intermediate ring groove 105. In addition, the connecting rod 102, in conjunction with the circumferential limiting groove 201, can also restrict the rotation of the pressure ring 200 relative to the nail seat 100, thereby keeping the first limiting boss 107 and the second limiting boss 202 aligned and abutting, thus improving structural stability.

[0040] like Figures 1 to 9As shown, the universal large-angle screw assembly method provided in this embodiment of the invention can be used to assemble the universal large-angle screw described in the above embodiments. The method includes: engaging one axial end of an intermediate ring 300 with a screw base 100, and providing a groove 308 extending from the inside to the outside at the other axial end of the intermediate ring 300, the groove 308 communicating with an opening 306 that penetrates the side wall of the intermediate ring 300 along the axial direction; passing a screw tail 400 through the screw base 100 and the intermediate ring 300, so that the ball head 401 at one end of the screw tail 400 is pressed into the intermediate ring 300; wherein, the intermediate ring 300 is radially expanded within the screw base 100, and the intermediate ring 300 radially presses the ball head 401.

[0041] See Figure 2 and Figure 7 In an optional embodiment, a side hole 104 may be provided on the side wall of the nail seat 100, and an instrument used with a universal large-angle screw may be connected to the side hole 104.

[0042] The universal high-angle screw obtained using the above assembly method allows the screw tail 400 to tilt within the opening range of the intermediate ring 300 and rotate 360 ​​degrees around the axis of the intermediate ring 300. Furthermore, the screw tail 400 can tilt into the slot 308, thereby obtaining a larger tilting angle. In the assembled universal high-angle screw, the ball head 401 fits within the intermediate ring 300, and can also fit between the pressure ring 200 and the intermediate ring 300 for limiting its position. The ball head 401 radially expands the intermediate ring 300, ensuring a stable assembly position and preventing the intermediate ring 300 from loosening relative to the screw seat 100 due to radial contraction, thus improving the overall structural stability of the universal high-angle screw. Additionally, the intermediate ring 300 exerts a clamping force on the ball head 401, and there is sliding friction resistance between them, thus limiting and locking the screw tail 400 within any tilting angle state within the constraint range of the intermediate ring 300.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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; and these 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 the present invention.

Claims

1. A universal large-angle screw, characterized in that, include: Pin seat (100), pressure ring (200), intermediate ring (300) and pin tail (400); The sidewall of the intermediate ring (300) is provided with an opening (306) that passes through the intermediate ring (300) along the axial direction. One axial end of the intermediate ring (300) is engaged with the nail seat (100), and the other axial end of the intermediate ring (300) is provided with a groove (308) that extends from the inside to the outside and connects to the opening (306). One end of the nail tail (400) is provided with a ball head (401), and the nail tail (400) passes through the nail seat (100) and the intermediate ring (300). The pressure ring (200) is installed in the nail seat (100), and the ball head (401) is movably fitted in the intermediate ring (300) and clamped by the intermediate ring (300).

2. The universal large-angle screw according to claim 1, characterized in that, The slot (308) includes an arcuate groove adapted to the nail tail (400); The axis of the arc groove is inclined from one end near the nail seat (100) to the end away from the nail seat (100) in a direction away from the axis of the intermediate ring (300).

3. The universal large-angle screw according to claim 1, characterized in that, The intermediate ring (300) has an inner ball groove (303) that is adapted to the ball head (401).

4. The universal large-angle screw according to claim 3, characterized in that, The cross-sectional diameter of the middle part of the inner ball groove (303) along the axial direction of the intermediate ring (300) is greater than the cross-sectional diameter of the two ends of the inner ball groove (303).

5. The universal large-angle screw according to any one of claims 1 to 4, characterized in that, The sidewall of the intermediate ring (300) is provided with a stiffness weakening groove (307), and the stiffness weakening groove (307) and the opening (306) are spaced apart along the circumference of the intermediate ring (300).

6. The universal large-angle screw according to any one of claims 1 to 4, characterized in that, The outer wall of the intermediate ring (300) is provided with a first protruding ring (301) and a second protruding ring (302). The first convex ring (301) and the second convex ring (302) are spaced apart along the axial direction of the intermediate ring (300), and an outer ring groove (304) is formed between the first convex ring (301) and the second convex ring (302). The pin seat (100) is fitted to the first convex ring (301) and the outer ring groove (304), and the intermediate ring (300) is rotated relative to the pin seat (100).

7. The universal large-angle screw according to claim 6, characterized in that, The nail seat (100) is provided with an intermediate ring groove (105) adapted to the first convex ring (301) and a pressure ring groove (106) adapted to the pressure ring (200). The inner wall of the pressure ring groove (106) is provided with a first limiting boss (107) that is adapted to the pressure ring (200).

8. The universal large-angle screw according to claim 7, characterized in that, The outer wall of the pressure ring (200) is provided with a second limiting boss (202) corresponding to the first limiting boss (107). The first limiting boss (107) is away from the end face of the pressure ring groove (106), and / or the end face of the second limiting boss (202) near the intermediate ring groove (105) is provided with an inclined surface that is inclined from the outside to the inside towards the intermediate ring groove (105).

9. The universal large-angle screw according to claim 1, characterized in that, The pressure ring (200) is provided with a circumferential limiting groove (201) at the end opposite to the nail tail (400); The nail seat (100) is provided with a radially penetrating notch, and a connecting rod (102) adapted to the circumferential limiting groove (201) can be detachably installed in the notch. The nail seat (100) is detachably fitted with a screw plug (101), and the connecting rod (102) is pressed between the screw plug (101) and the pressure ring (200).

10. A method for assembling a universal large-angle screw, characterized in that, include: One axial end of the intermediate ring (300) is snapped into the nail seat (100), and the other axial end of the intermediate ring (300) is provided with a groove (308) extending from the inside to the outside. The groove (308) is connected to an opening (306) that penetrates the side wall of the intermediate ring (300) along the axial direction. The nail tail (400) is passed through the nail seat (100) and the intermediate ring (300) so that the ball head (401) at one end of the nail tail (400) is pressed into the intermediate ring (300); wherein the intermediate ring (300) is radially expanded within the nail seat (100) and the intermediate ring (300) radially presses the ball head (401).

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