Special-shaped spring winding device and method
By providing a special-shaped spring winding device including a fixing device, a rotating handle and a pin shaft, the problem of difficulty in winding the special-shaped spring hook in the prior art is solved, and convenient winding of the special-shaped spring end hook is achieved .
Patent Information
- Application Number
- CN202411784757.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-06
- Publication Date
- 2025-02-18
AI Technical Summary
The prior art is difficult to easily wind the hooks on the spring wire of the special-shaped spring, especially in speed regulator products, it is difficult to manually wind the hooks on the ends of the spring wire of the special-shaped spring.
Provided is a special-shaped spring winding device, including a fixing device, a rotary handle and a pin shaft. The spring is fixed in the circumference and axial direction of the spring through the fixing device. The pin hole on the rotary handle is inserted on the pin shaft and reserved. The spring wire is sandwiched between the winding head and the pin shaft, and the rotating handle is rotated to fit the reserved spring wire and the outer side of the pin shaft and form a hook.
Through the coordination of the rotating handle, pin shaft and fixed structure, the hook at the end of the special-shaped spring can be easily wound, which solves the problem of difficulty in winding the special-shaped spring hook in the prior art.
Smart Images
Figure CN119456869A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of special-shaped spring production and manufacturing, and in particular to a special-shaped spring winding device and method. Background Art
[0002] Special-shaped springs are springs designed to meet specific functions. Most of them have special shapes, and the dimensions and shape and position tolerances of each part are designed separately according to actual requirements. For some speed regulator products, in order to achieve the function of the speed regulator, the internal structure requires a special-shaped spring with a hook at the end of the spring wire. For such special-shaped springs, it is difficult to manually wind the hook at the end of the spring wire of the special-shaped spring according to the designed size. Therefore, there is an urgent need for a special-shaped spring winding device and method that is convenient for winding the hook on the special-shaped spring. Summary of the invention
[0003] The object of the present invention is to provide a device and method for winding a special-shaped spring, so as to solve the problems existing in the above-mentioned prior art and make it easier to wind the upper hook of the special-shaped spring.
[0004] To achieve the above object, the present invention provides the following solutions:
[0005] The present invention provides a special-shaped spring winding device, comprising: a fixing device, a rotating handle and a pin shaft, wherein the fixing device is used to fix the spring in the circumferential direction and axial direction of the spring, the pin shaft is connected to the fixing device and is fixed in position in a direction perpendicular to the axis of the pin shaft, the axis of the pin shaft is parallel to the axis of the spring fixed on the fixing device and has a spacing, the cross-sectional shape of the pin shaft along a perpendicular to its own axis is circular, one end of the rotating handle is a winding end, a pin hole is arranged on the winding end, a winding head is also fixedly connected to the winding end, a spacing is provided between the winding head and the pin hole, the pin shaft can be inserted into the pin hole, a reserved spring wire is arranged between the winding head and the pin shaft, the side surfaces of the winding head and the pin shaft can contact the reserved spring wire at the same time, the rotating handle can rotate around the pin shaft and drive the winding head to rotate around the pin shaft, so that the reserved spring wire adapts to the deformation of the outer side surface of the pin shaft and forms a hook.
[0006] In some embodiments, the fixing device includes a core shaft, a support disk and a clamping structure, one side of the support disk is fixedly connected to one end of the core shaft, the length of the core shaft is less than the length of the spring in a natural state, the outside of the core shaft is used to sleeve the spring and one end of the spring can contact the support disk, the end of the spring away from the support disk is the first end, the clamping structure is detachably fixedly connected to the core shaft, the clamping structure can clamp at least one spring coil of the spring from the first end, and the pin is arranged on the clamping structure and is parallel to the axis of the core shaft.
[0007] In some embodiments, the clamping structure includes a fixing plate, a fixing bolt and a clamping piece, the fixing plate being capable of being inserted into a gap between two adjacent spring coils on a portion of the spring that is longer than the core shaft in a natural state, the fixing plate being provided with a through hole, a screw hole being provided on an end face of the core shaft away from the support disk, the through hole being able to penetrate the screw hole, the clamping piece and the fixing bolt forming a fixed connection in the axial direction of the fixing bolt, the fixing bolt being able to pass through the through hole and being screwed into the screw hole, as the fixing bolt is screwed into the screw hole to a greater depth, the clamping piece can press the spring coil onto the fixing plate and press the fixing plate onto the end of the core shaft away from the support disk, the fixing plate being provided with a mounting hole, the pin being able to be inserted into the mounting hole and forming a detachable connection with the mounting hole.
[0008] In some embodiments, a limiting portion is further included, wherein the limiting portion is fixedly connected to a side of the support plate away from the core shaft, and the cross section of the limiting portion along a direction perpendicular to the axial direction of the core shaft is rectangular.
[0009] In some embodiments, the rotating handle includes a winding portion and a rotating rod, one end of the winding portion forms the winding end, the rotating rod passes through and is fixedly connected to the winding portion, and the rotating rod is perpendicular to the extension direction of the pin hole.
[0010] In some embodiments, four mounting holes are provided, and they are respectively a first mounting hole, a second mounting hole, a third mounting hole and a fourth mounting hole. There are four mounting holes, and each of the pin shafts can be inserted into one of the mounting holes. The first mounting hole and the second mounting hole are located on one side of the through hole, and the third mounting hole and the fourth mounting hole are located on the other side of the through hole. A pin shaft can be inserted into each of the mounting holes. The handle has multiple models, and the sizes of the pin holes on the handles of different models are different. Each of the pin shafts has a handle with a pin hole of corresponding size to match it.
[0011] In some embodiments, a limiting shaft is further included, and a limiting hole is provided on the support plate, the limiting hole can correspond to the position of the first mounting hole, and the limiting shaft can be inserted into the limiting hole and the first mounting hole at the same time.
[0012] In some embodiments, a threaded hole is provided on the pressing member, and the fixing bolt passes through the threaded hole and forms a threaded connection with the threaded hole.
[0013] In some embodiments, the winding head is cylindrical.
[0014] The present invention also provides a method for winding a special-shaped spring, comprising the following steps:
[0015] Winding the spring: Use a winding tool to wind the spring, and reserve two sections of spring wire at both ends of the spring wire for forming hooks;
[0016] Winding special-shaped springs: Use a fixing device to fix the spring, then insert the pin hole on the rotating handle onto the pin shaft, and clamp the reserved spring wire between the winding head and the pin shaft, then turn the rotating handle to make the reserved spring wire fit against the outer side of the pin shaft and wind it to form a hook.
[0017] Compared with the prior art, the present invention has achieved the following technical effects:
[0018] The special-shaped spring winding device provided by the present invention first uses a lathe or other winding devices to wind the spring, and reserves a certain length at the end of the spring wire to form a reserved spring wire, and then uses a fixing device to fix the spring in the circumferential and axial directions of the spring, then inserts the pin hole on the rotating handle into the pin shaft, and clamps the reserved spring wire between the winding head and the pin shaft, and then rotates the rotating handle to make the reserved spring wire fit with the outer side surface of the pin shaft to form a hook. Through the cooperation of the rotating handle, the pin shaft and the fixing structure, the hook at the end of the special-shaped spring can be conveniently wound. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0020] Figure 1 A top view of a fixing plate in some embodiments of the present invention;
[0021] Figure 2 A cross-sectional view of a rotary handle in some embodiments of the present invention;
[0022] Figure 3It is a front view of the core shaft, the support plate and the limiting part in some embodiments of the present invention;
[0023] Figure 4 A front view of a pin in some embodiments of the present invention;
[0024] Figure 5 A top view of a special-shaped spring wound by using a special-shaped spring winding device in some embodiments of the present invention;
[0025] In the figure: 1, rotary handle; 11, pin hole; 12, winding head; 13, winding part; 2, pin shaft; 3, core shaft; 31, screw hole; 4, support plate; 41-limiting hole; 5, fixing plate; 51, first mounting hole; 52, second mounting hole; 53, third mounting hole; 54, fourth mounting hole; 55, through hole; 6, limiting part; 7, first reserved spring wire; 71, first hook; 72, second hook; 8, second reserved spring wire; 81, third hook; 82, fourth hook; 9, spring body. DETAILED DESCRIPTION
[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0027] The object of the present invention is to provide a device and method for winding a special-shaped spring, so as to solve the problems existing in the above-mentioned prior art and make it easier to wind the upper hook of the special-shaped spring.
[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0029] Embodiment 1
[0030] This embodiment provides a special-shaped spring winding device, such as Figure 1-4As shown, it includes: a fixing device, a handle 1 and a pin 2, the fixing device is used to fix the spring in the circumferential and axial directions of the spring, the pin 2 is connected to the fixing device and is fixed in a direction perpendicular to the axis of the pin 2, the axis of the pin 2 is parallel to the axis of the spring fixed on the fixing device and has a spacing, the cross-sectional shape of the pin 2 along the perpendicular to its own axis is circular, one end of the handle 1 is a winding end, a pin hole 11 is arranged on the winding end, a winding head 12 is also fixedly connected to the winding end, there is a spacing between the winding head 12 and the pin hole 11, the pin 2 can be inserted into the pin hole 11, a reserved spring wire is arranged between the winding head 12 and the pin 2, the side surfaces of the winding head 12 and the pin 2 can contact with the reserved spring wire at the same time, the handle 1 can rotate around the pin 2 and drive the winding head 12 to rotate around the pin 2, so that the reserved spring wire adapts to the deformation of the outer side surface of the pin 2 and forms a hook.
[0031] The special-shaped spring winding device provided in this embodiment first uses a lathe or other winding device to wind the spring, and reserves a certain length at the end of the spring wire to form a reserved spring wire, and then uses a fixing device to fix the spring in the circumferential and axial directions of the spring, then inserts the pin hole 11 on the rotating handle 1 into the pin shaft 2, and clamps the reserved spring wire between the winding head 12 and the pin shaft 2, and then rotates the rotating handle 1 to make the reserved spring wire fit with the outer side of the pin shaft 2 and form a hook. Through the cooperation of the rotating handle 1, the pin shaft 2 and the fixing structure, the hook at the end of the special-shaped spring can be easily wound. Among them, the pin shaft 2 is preferably cylindrical.
[0032] In one implementation of this embodiment, the fixing device includes a mandrel 3, a support disk 4 and a clamping structure, one side of the support disk 4 is fixedly connected to one end of the mandrel 3, the length of the mandrel 3 is less than the length of the spring in the natural state, the outside of the mandrel 3 is used to sleeve the spring and one end of the spring can contact the support disk 4, the end of the spring away from the support disk 4 is the first end, the clamping structure is detachably fixedly connected to the mandrel 3, the clamping structure can clamp at least one spring coil of the spring from the first end, and the pin 2 is fixedly connected to the clamping structure and is parallel to the axis of the mandrel 3. When fixing the spring, the spring is sleeved on the mandrel 3, and then the clamping structure is used to clamp at least one spring coil of the spring from the first end, so as to complete the axial and circumferential fixation of the spring.
[0033] In one implementation of the present embodiment, the clamping structure includes a fixing plate 5, a fixing bolt and a clamping piece. The fixing plate 5 can be inserted into the gap between two adjacent spring coils on the part of the spring that is longer than the core shaft 3 in the natural state. A through hole 55 is provided on the fixing plate 5. A screw hole 31 is provided on the end surface of the core shaft 3 away from the support disk 4. The through hole 55 and the screw hole 31 can be connected. The clamping piece and the fixing bolt form a fixed connection in the axial direction of the fixing bolt. The fixing bolt can pass through the through hole 55 and be screwed into the screw hole 31. As the depth of the fixing bolt screwed into the screw hole 31 increases, the clamping piece can press the spring coil onto the fixing plate 5 and press the fixing plate 5 onto the end of the core shaft 3 away from the support disk 4. A mounting hole is provided on the fixing plate 5. The pin 2 can be inserted into the mounting hole and form a detachable connection with the mounting hole. When clamping the spring, the fixing plate 5 is inserted between two adjacent spring coils of the spring, and the fixing bolt is passed through the through hole 55 on the fixing plate 5, and then the fixing bolt is screwed into the screw hole 31 on the core shaft 3. As the fixing bolt is screwed into the screw hole 31, the pressing member moves in the direction where the support plate 4 is located, and presses several spring coils of the spring on the fixing plate 5, and also presses the fixing plate 5 on the end surface of the core shaft 3. At this time, a part of the spring coils of the spring are clamped between the fixing plate 5 and the pressing member, and the pressing member also fixes the fixing plate 5 on the core shaft 3. Among them, the fixing plate 5 is preferably inserted between the first spring coil and the second spring coil on the part of the spring that is longer than the core shaft 3 in the natural state.
[0034] In one implementation of this embodiment, the special-shaped spring winding device provided in this embodiment further includes a limiting portion 6, which is fixedly connected to the side of the support plate 4 away from the core shaft 3, and the cross section of the limiting portion 6 along the axis perpendicular to the core shaft 3 is rectangular. When winding the spring, the limiting portion 6 can be inserted into a rectangular hole or a limiting groove matching the cross-sectional shape of the limiting portion 6, and the entire device is limited, which is more labor-saving than manually grasping the special-shaped spring winding device to limit.
[0035] In one implementation of this embodiment, the rotary handle 1 includes a winding portion 13 and a rotating rod, one end of the winding portion 13 forms a winding end, the rotating rod passes through and is fixedly connected to the winding portion 13, and the rotating rod is perpendicular to the extension direction of the pin hole 11. The staff can rotate the winding portion 13 through the rotating rod, so that the rotation of the rotary handle 1 is more labor-saving.
[0036] In one implementation of this embodiment, there are four mounting holes, which are respectively the first mounting hole 51, the second mounting hole 52, the third mounting hole 53 and the fourth mounting hole 54. There are four mounting holes, and each pin shaft 2 can be inserted into one mounting hole. The first mounting hole 51 and the second mounting hole 52 are located on one side of the through hole 55, and the third mounting hole 53 and the fourth mounting hole 54 are located on the other side of the through hole 55. A pin shaft 2 can be inserted into each mounting hole. The handle 1 has multiple models, and the sizes of the pin holes 11 on the handles 1 of different models are different. Each pin shaft 2 has a handle 1 with a pin hole 11 of a corresponding size to match it. Figure 5 As shown, a section of spring wire is reserved at each end of the special-shaped spring, and two hooks need to be wound on the two sections of reserved spring wire. When winding, the spring can be fixed first, and the pin shaft 2 corresponding to the first mounting hole 51 and the second mounting hole 52 can be inserted into the first mounting hole 51 and the second mounting hole 52 respectively, and then the two hooks on a section of reserved spring wire are wound using the handle 1 corresponding to the first mounting hole 51 and the second mounting hole 52. After that, the spring is removed and reversed to fix the spring, and the pin shaft 2 corresponding to the third mounting hole 53 and the fourth mounting hole 54 can be inserted into the third mounting hole 53 and the fourth mounting hole 54 respectively, and the handle 1 corresponding to the pin shaft 2 on the third mounting hole 53 and the fourth mounting hole 54 is used to complete the winding of the reserved spring wire at the other end of the spring. Among them, the diameter of the first mounting hole 51 is 4mm, the cross-sectional diameter of the second mounting hole 52 is 2mm, the cross-sectional diameter of the third mounting hole 53 is 2mm, and the diameter of the fourth mounting hole 54 is 6mm. The diameters of the four mounting holes correspond to the diameters of the four hooks on the special-shaped spring.
[0037] In one implementation of the present embodiment, the special-shaped spring winding device provided in the present embodiment further includes a limiting shaft, a limiting hole 41 is provided on the support plate 4, the limiting hole 41 can correspond to the position of the first mounting hole 51, and the limiting shaft can be inserted into the limiting hole 41 and the first mounting hole 51 at the same time. After the winding of the hook at one end of the spring is completed, in order to make the relative position of the hook at the other end and the completed winding hook meet the design requirements, the limiting shaft can be inserted into the first mounting hole 51 and the limiting hole 41 after adjusting the position of the spring, and the rotation of the fixing plate 5 is limited by the limiting shaft, so that the position of the pin 2 is fixed, thereby preventing the spring from rotating during the rotation of the handle.
[0038] In order to facilitate the disassembly and replacement of the pressing member, in one implementation of this embodiment, a threaded hole is provided on the pressing member, and the fixing bolt passes through the threaded hole and forms a threaded connection with the threaded hole.
[0039] In one implementation of this embodiment, the winding head 12 is cylindrical in shape. The outer side of the winding head 12 is a cylindrical surface, which, compared with a prism with edges and corners, has less friction between the winding head 12 and the spring wire during winding.
[0040] Embodiment 2
[0041] This embodiment provides a method for winding a special-shaped spring, comprising the following steps:
[0042] Winding the spring: Use a winding tool to wind the spring, and reserve two sections of spring wire at both ends of the spring wire for forming hooks;
[0043] Winding special-shaped springs: Fix the spring with a fixing device, then insert the pin hole on the rotating handle onto the pin shaft, and clamp the reserved spring wire between the winding head 12 and the pin shaft 2, then rotate the rotating handle 1 to make the reserved spring wire fit with the outer side of the pin shaft and wind it to form a hook.
[0044] Embodiment 3
[0045] This embodiment provides a specific example of using the special-shaped spring winding device of the first embodiment and the special-shaped spring winding method of the second embodiment to wind a spring:
[0046] like Figure 4 As shown, the special-shaped spring includes a first reserved spring wire 7, a second reserved spring wire 8 and a spring body 9. The first reserved spring wire 7 and the second reserved spring wire 8 are located at both ends of the spring body 9. The specific size requirements are as follows (unit: mm): the length of the spring body is 15, the tolerance is ±0.8, the diameter of the spring body 9 is 31.4, the tolerance is ±0.5, the arc on the first reserved spring wire 7 close to the spring body 9 is the first hook 71, the radius of which is 3, the tolerance is 0~+0.8, the arc on the first reserved spring wire 7 close to the spring body 9 It is the second hook 72, whose radius is 1.5 and the tolerance is ±0.3. The arc on the second reserved spring wire 8 close to the spring body 9 is the third hook 81, whose radius is 1.5 and the tolerance is 0~+0.6. The arc on the second reserved spring wire 8 away from the spring body 9 is the fourth hook 82, whose radius is 4. The distance from the end of the first reserved spring wire 7 away from the spring body 9 to the center of the spring body 9 is 25 and the tolerance is ±1.5. The distance from the end of the second reserved spring wire 8 away from the spring body 9 to the center of the spring body 9 is 27 and the tolerance is ±1.5.
[0047] After production, the dimensions of the special-shaped spring are as follows (in mm):
[0048] The thickness of the spring body is 15.2, the diameter of the spring body 9 is 31.4, the radius of the first hook 71 is 3.3, the radius of the second hook 72 is 1.6, the radius of the third hook 81 is 1.7, the radius of the fourth hook 82 is 4, the distance from the end of the first reserved spring wire 7 away from the spring body 9 to the center of the spring body 9 is 25.5, and the distance from the end of the second reserved spring wire 8 away from the spring body 9 to the center of the spring body 9 is 26.5.
[0049] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.
Claims
1. A special-shaped spring winding device, characterized in that: include: A fixing device, a rotating handle and a pin shaft, wherein the fixing device is used to fix the spring in the circumferential and axial directions of the spring, the pin shaft is connected to the fixing device and is fixed in a direction perpendicular to the axis of the pin shaft, the axis of the pin shaft is parallel to the axis of the spring fixed to the fixing device and has a spacing therebetween, the cross-sectional shape of the pin shaft along a cross-section perpendicular to its own axis is circular, one end of the rotating handle is a winding end, a pin hole is arranged on the winding end, a winding head is also fixedly connected to the winding end, a spacing is provided between the winding head and the pin hole, the pin shaft can be inserted into the pin hole, a reserved spring wire is arranged between the winding head and the pin shaft, the side surfaces of the winding head and the pin shaft can contact the reserved spring wire at the same time, the rotating handle can rotate around the pin shaft and drive the winding head to rotate around the pin shaft, so that the reserved spring wire adapts to the deformation of the outer side surface of the pin shaft and forms a hook.
2. The special-shaped spring winding device according to claim 1, characterized in that: The fixing device includes a core shaft, a support disk and a clamping structure, one side of the support disk is fixedly connected to one end of the core shaft, the length of the core shaft is less than the length of the spring in a natural state, the outside of the core shaft is used to sleeve the spring and one end of the spring can contact the support disk, the end of the spring away from the support disk is the first end, the clamping structure is detachably fixedly connected to the core shaft, the clamping structure can clamp at least one spring coil of the spring starting from the first end, and the pin is arranged on the clamping structure and is parallel to the axis of the core shaft.
3. The special-shaped spring winding device according to claim 2, characterized in that: The clamping structure includes a fixing plate, a fixing bolt and a clamping piece, wherein the fixing plate can be inserted into the gap between two adjacent spring coils on the part of the spring that is longer than the core shaft in the natural state, the fixing plate is provided with a through hole, and a screw hole is provided on the end surface of the core shaft away from the support plate, the through hole and the screw hole can be connected, the clamping piece and the fixing bolt form a fixed connection in the axial direction of the fixing bolt, the fixing bolt can pass through the through hole and be screwed into the screw hole, and as the depth of the fixing bolt screwed into the screw hole increases, the clamping piece can press the spring coil onto the fixing plate and press the fixing plate onto the end of the core shaft away from the support plate, the fixing plate is provided with a mounting hole, and the pin shaft can be inserted into the mounting hole and form a detachable connection with the mounting hole.
4. The special-shaped spring winding device according to claim 2, characterized in that: It also includes a limiting portion, which is fixedly connected to a side of the support plate away from the core shaft, and the cross section of the limiting portion along the axis perpendicular to the core shaft is rectangular.
5. The special-shaped spring winding device according to claim 1, characterized in that: The rotating handle includes a winding portion and a rotating rod, one end of the winding portion forms the winding end, the rotating rod passes through and is fixedly connected to the winding portion, and the rotating rod is perpendicular to the extending direction of the pin hole.
6. The special-shaped spring winding device according to claim 3, characterized in that: There are four mounting holes, which are respectively a first mounting hole, a second mounting hole, a third mounting hole and a fourth mounting hole. There are four mounting holes, and each of the pin shafts can be inserted into one of the mounting holes. The first mounting hole and the second mounting hole are located on one side of the through hole, and the third mounting hole and the fourth mounting hole are located on the other side of the through hole. A pin shaft can be inserted into each of the mounting holes. The rotary handle has multiple models, and the sizes of the pin holes on the rotary handles of different models are different. Each of the pin shafts has a rotary handle with a pin hole of corresponding size to match it.
7. The special-shaped spring winding device according to claim 6, characterized in that: It also includes a limiting shaft. The support plate is provided with a limiting hole. The limiting hole can correspond to the position of the first mounting hole. The limiting shaft can be inserted into the limiting hole and the first mounting hole at the same time.
8. The special-shaped spring winding device according to claim 3, characterized in that: The clamping member is provided with a threaded hole, and the fixing bolt passes through the threaded hole and forms a threaded connection with the threaded hole.
9. The special-shaped spring winding device according to claim 1, characterized in that: The winding head is cylindrical.
10. A method for winding a special-shaped spring, characterized in that: The following steps are involved: Winding the spring: Use a winding tool to wind the spring, and reserve two sections of spring wire at both ends of the spring wire for forming hooks; Winding special-shaped springs: Use a fixing device to fix the spring, then insert the pin hole on the rotating handle onto the pin shaft, and clamp the reserved spring wire between the winding head and the pin shaft, then turn the rotating handle to make the reserved spring wire fit against the outer side of the pin shaft and wind it to form a hook.