Manufacturing method of head pin of biopsy forceps

Abstract

The invention relates to a method for manufacturing a head pin of biopsy forceps, which comprises the following steps of: forming a head part with a through hole by using a stamping process; forming a pin part by utilizing a wire drawing process, wherein the diameter of the pin part is smaller than the inner diameter of the through hole; one end of the pin part is placed in a limiting hole of a welding jig, the other end of the pin part protrudes out of the welding jig to form a fixed end, and the error between the length of the fixed end and the thickness of the head part ranges from + 0.08 mm to-0.01 mm; the through hole of the head part is sleeved on the fixed end, and the head part and the fixed end are welded, so that the head part is fixed at the fixed end, and the head pin with an accurate size can be manufactured.

Description

Technical Field

[0001] The invention relates to a method for manufacturing a headed pin which is low-cost, easy to manufacture and high-precision. Background Art

[0002] Biopsy forceps is a medical device mainly used to take samples from human tissue for examination. Biopsy forceps are usually made of stainless steel or other high-strength medical materials. They are mainly used to accurately grasp a small amount of tissue for pathological analysis of the lesion area.

[0003] The structure of the biopsy forceps is as shown in the utility model patent case CN204033383U "Biopsy Forceps" announced by China on December 24, 2014. It discloses that: the forceps head assembly includes a left forceps head, a right forceps head, a left wire hook, a right wire hook, a forceps head seat and a pin tube, the left forceps head and the right forceps head are hingedly mounted on the forceps head seat through the pin tube, the left wire hook and the right wire hook are respectively connected to the left forceps head and the right forceps head, the left wire hook and the right wire hook are both formed with a connecting head at the front end of their straight wires by bending, the connecting heads of the left wire hook and the right wire hook are respectively connected to the forceps head holes at the tail ends of the left forceps head and the right forceps head, the bending part of the connecting head is inserted into the forceps head hole, and the folding part of the connecting head is larger than the aperture of the forceps head hole to limit its escape from the forceps head hole.

[0004] The patent case uses a double control line connecting rod structure of left and right wire hooks to control the left and right clamp heads. The disadvantage is that the control method of this mechanism is less flexible and the operation feel is poor. In addition, in order to meet the clamping force requirements, the control line size cannot be too thin, so the control line is thicker, resulting in the smaller the size of the biopsy forceps mechanism, the worse its operating performance will be, especially when used for 1.0mm thin biopsy forceps, the operating performance and flexibility will be greatly limited.

[0005] There is also a patent case of utility model number CN2850522Y "Improved Endoscopic Biopsy Forceps" announced by China on December 27, 2006. It discloses that it is composed of two clamp heads, a clamp head frame, a left connecting rod, a right connecting rod, a pull rod and an outer tube. The left connecting rod and the right connecting rod are respectively hinged to the two clamp heads, and the other ends of the left and right connecting rods are hinged to the pull rod. The clamp head frame is connected to the outer tube. A pin for hinge connection with the left and right connecting rods is fixed on the clamp head. The left connecting rod is composed of a rod body and a cylindrical boss perpendicular to the rod body, and the cylindrical boss is fixed to one end of the rod body. The other end of the left connecting rod has a hinge hole, and both ends of the right connecting rod have hinge holes.

[0006] The patent case mainly utilizes the left connecting rod to have an integral cylindrical boss, which is inserted into the hinge hole of the right connecting rod to form a four-link group. Since the connecting rod and the clamp head of this mechanism are only connected by sleeves and there is no structure to prevent them from falling off, high-strength clamp heads and connecting rods are required to prevent deformation of parts and prevent the connection mechanism from falling off and failing. In particular, this mechanism is only suitable for large-sized biopsy forceps and cannot be applied to the manufacturing technology of small-sized (1.0mm) biopsy forceps.

[0007] There is also a utility model patent case CN214414847U "A jaw and biopsy forceps" announced by China on October 19, 2021. It discloses that: the jaw includes a clamping end and a connecting end connected to the clamping end; the connecting end is provided with a first connecting hole and a connecting rivet; the connecting rivet is provided at the rear end of the first connecting hole, and the connecting rivet and the connecting end are an integrated structure. When assembling the biopsy forceps, the jaws can be assembled by directly inserting the connecting rivet into the corresponding connecting hole on the connecting rod.

[0008] The patent case mainly uses the riveting method of connecting rivets to form a four-bar linkage. Since the size of the rivet pin is quite limited, it is only suitable for larger biopsy forceps. Due to the size limitation of rivets and riveting technology, it cannot be made too small and cannot be applied to the manufacturing technology of small-sized (1.0mm) biopsy forceps.

[0009] Therefore, in order to manufacture small-sized biopsy forceps, it is necessary to use customized headed pins, which are used as the connection of the four-bar linkage, so that the assembled biopsy forceps can have better comprehensive performance. However, customized headed pins require higher processing quality, usually using precision machining technology (CNC), which is expensive, and requires precise shaft dimensions. High-frequency measurements are required during processing, which is time-consuming and costly.

[0010] The structure and assembly of the head pin can refer to the invention patent No. CN117584061A "ribbed connecting rod processing part for making biopsy forceps" published in China on February 23, 2024. It is disclosed that the head pin is welded and fixed to one of the clamp cups, so that one of the clamp cups can be pivoted to the second pivot part of the connecting rod, and the above method is repeated to pivot the other clamp cup to the connecting rod with another head pin, so that the two clamp cups can be opened or closed by the connecting rod and the connecting rod.

[0011] The patent prior art provides a manufacturing technology for small-sized (1.0 mm) biopsy forceps by assembling a four-link group with a head pin. However, the manufacturing cost of the head pin is currently high, making the manufacturing of small-sized biopsy forceps difficult and unable to significantly reduce the manufacturing cost. Summary of the invention

[0012] Therefore, in view of the above-mentioned disadvantages of the headed pin currently used in biopsy forceps, an object of the present invention is to provide a method for manufacturing the headed pin of biopsy forceps.

[0013] The present invention provides a method for manufacturing a headed pin of a biopsy forceps, which is characterized by comprising the following steps: forming a head portion by a stamping process, wherein the head portion has a through hole; forming a pin portion by a wire drawing process, wherein the diameter of the pin portion is smaller than the inner diameter of the through hole; placing one end of the pin portion in a limiting hole of a welding fixture, so that the other end of the pin portion protrudes out of the welding fixture to become a fixed end, and the length of the fixed end and the thickness error of the head portion are +0.08 to -0.01 mm; fitting the through hole of the head portion onto the fixed end, applying a welding process to the head portion and the fixed end, so that the head portion is fixed to the fixed end, thereby manufacturing a headed pin.

[0014] The head portion is configured to be in a circular ring shape, and the pin portion is configured to be in a round rod shape.

[0015] The stamping process is to place a blank between a male die and a female die of a stamping die, and to manufacture the head with the through hole in an integrated manner through continuous stamping.

[0016] The outer diameter of the head is 0.44-0.5 mm, the thickness of the head is 0.1-0.15 mm, the inner diameter of the through hole is 0.25-0.35 mm, and the diameter of the pin is 0.25-0.35 mm.

[0017] The surface of the welding fixture has a working plane, on which one or more limiting holes are arranged, and the depth of the limiting holes is less than the sum of the length of the pin portion and the thickness of the head portion.

[0018] The depth of the limiting hole is 4.88 mm, and the length of the fixed end is 0.1-0.15 mm.

[0019] The two vertically opposite side surfaces of the welding fixture are connected to each other and are provided with a slot extending through to the lower position of the limiting hole.

[0020] The welding process is performed on the head and the fixing end using a welding device, and the welding device can be a laser welding machine, a spot welding machine, an electron beam welding machine or a plasma welding machine.

[0021] The head is formed in one piece and connected with a support member. After the through hole of the head is fitted on the fixed end, the support member is fixed and then the welding process is performed. After the welding is completed, the support member of the head is removed.

[0022] The stamping process is to place a blank between a male die and a female die of a stamping die, and to manufacture the head and the support member having the through hole in an integrated manner through continuous stamping.

[0023] The length of the support member is 5.8 mm, and the thickness of the support member is 0.12 mm.

[0024] The support member is fixed by a clamp or a jig manually or automatically to prevent the head from shaking.

[0025] The support member to which the head is connected is removed by using pliers and grinding equipment.

[0026] According to the above technical features, it has the following advantages:

[0027] 1. It is possible to produce a head pin structure with precise dimensions, and the overall advantages include low cost and good size control.

[0028] 2. The stamping process is mass-producible. In addition to the low cost of parts, the tolerance of the through hole in the head can reach ±0.01mm. The pin part uses a wire drawing process to draw out a whole roll of stainless steel wire with a precise diameter, with a tolerance of ±0.003mm. After cutting out the same length, the pin part can be completed. Therefore, the manufacturing method is simple, the operation steps are extremely easy, and the accuracy is very high.

[0029] 3. After the head pin is assembled on the biopsy forceps, the biopsy forceps have excellent maneuverability due to the accurate diameter of the head pin. Also, due to the larger head of the head pin, the risk of parts slipping off is extremely small, the failure rate is low, and the service life is long. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The figure is an operation flow chart of an embodiment of the present invention.

[0031] Figure 2 It is a three-dimensional appearance diagram of the head and the pin part of an embodiment of the present invention.

[0032] Figure 3 This is a three-dimensional appearance diagram of a welding fixture according to an embodiment of the present invention.

[0033] Figure 4 This is a schematic diagram of a pin portion placed in a limiting hole according to an embodiment of the present invention.

[0034] Figure 5 It is a schematic diagram of the through hole of the head in an embodiment of the present invention being sleeved on the fixed end.

[0035] Figure 6 It is a schematic diagram of the head and the fixed end being fixed by welding according to an embodiment of the present invention.

[0036] Figure 7 This is a schematic diagram of the appearance of a completed head pin according to an embodiment of the present invention.

[0037] Figure 8 This is a three-dimensional exploded view of a head pin assembled on a biopsy forceps according to an embodiment of the present invention.

[0038] Fig. 9 This is a three-dimensional combination diagram of a head pin assembled on a biopsy forceps according to an embodiment of the present invention.

[0039] Fig.10 FIG. 4 is an operation flow chart of another embodiment of the present invention.

[0040] Explanation of the reference numerals: 1-head; 11-through hole; 12-support member; 2-pin portion; 3-welding fixture; 31-working plane; 32-limiting hole; 5-biopsy forceps; 51-single-strand drive cable; 511-driving end; 512-first pivot hole; 52-driving connecting rod; 521-second pivot hole; 522-third pivot hole; 53-jaw portion; 531-fourth pivot hole; 54-jaw head frame; 541-pin member; 55-flexible sleeve; 56-pin shaft; 57-headed pin; 571-pin portion; A-outer diameter; B-thickness; C-inner diameter; D-length; E-thickness; F-diameter; G-length; H-depth; I-length. DETAILED DESCRIPTION

[0041] See also Figure 1 and Figure 2 As shown, the embodiment of the present invention includes the following steps:

[0042] A. A head is formed by a stamping process, and the head has a through hole, and the head is connected to a support. The ring-shaped head 1 is mainly formed by a continuous stamping process, and a through hole 11 is formed at the center of the head 1, and the head 1 is horizontally integrally formed and connected to a support 12. It is made of stainless steel. The continuous stamping process is to put a blank between the male mold and the female mold of a stamping mold, and through continuous stamping, the head 1 with the through hole 11 and its support 12 are integrally formed. The outer diameter A of the formed head 1 is 0.44-0.5mm, the thickness B of the head 1 is 0.1-0.15mm, and the inner diameter C of the through hole 11 is 0.25-0.35mm. The best outer diameter A of the head 1 is 0.46mm, the thickness B of the head 1 is 0.12mm, and the inner diameter C of the through hole 11 is 0.305mm. The length D of the support member 12 is 5.8 mm, and the thickness E of the support member 12 is 0.12 mm (which is the same as the thickness B of the head 1 because they are integrally formed from a plate of the same thickness).

[0043] B. A pin portion in the shape of a round rod is formed by a wire drawing process, and the diameter of the pin portion is smaller than the inner diameter of the through hole. The pin portion 2 is mainly formed by a wire drawing process by rolling a whole roll of stainless steel wire with a precise diameter. The diameter F of the formed pin portion 2 is 0.25-0.35 mm, and the optimal diameter F of the pin portion 2 is 0.3 mm. The length G of the pin portion 2 is 5 mm.

[0044] C. Place one end of the pin into a limiting hole of a welding fixture, so that the other end of the pin protrudes out of the welding fixture to become a fixed end. The length of the fixed end and the thickness error of the head are +0.08 to -0.01mm. Figure 3 and Figure 4 As shown, the embodiment of the present invention is implemented in conjunction with the welding jig 3. The surface of the welding jig 3 has a working plane 31. The working plane 31 is provided with one or more limiting holes 32. The depth H of the limiting hole 32 is less than the sum of the length G of the pin portion 2 and the thickness B of the head 1. The depth H of the limiting hole 32 is 4.88 mm. In addition, the two vertical opposite side surfaces 32 of the welding jig 3 are connected and provided with a slot 33 extending to the lower position of the limiting hole 32. One end of the pin portion 2 is placed straight into the limiting hole 32, so that the other end of the pin portion 2 protrudes from the outside of the welding jig 3 to become the fixed end 21. The error of the length I of the fixed end 21 with respect to the thickness B of the head 1 is +0.08 to -0.01 mm. The length of the fixed end is 0.1 to 0.15 mm. The best length I of the fixed end 21 is 0.12 mm.

[0045] D. Fit the through hole of the head onto the fixed end, fix the support, and perform welding process on the head and the fixed end to fix the head to the fixed end. Figure 5 As shown, the through hole 11 of the head 1 is fitted onto the fixed end 21. Then, a clamp or a jig is used to fix the support member 12 manually or automatically to prevent the head 1 from shaking. Then, a welding process is performed on the head 1 and the fixed end 21 using a welding device, so that the head 1 and the fixed end 21 are welded and fixed. Figure 6 The welding device can be a laser welding machine, a spot welding machine, an electron beam welding machine or a plasma welding machine.

[0046] E. Remove the support of the head to make a headed pin. Then use pliers and grinding equipment to remove the support 12 connected to the head 1, such as Figure 7As shown, a headed pin with accurate dimensions and integrity can be manufactured. The headed pin manufactured by the manufacturing method has a tolerance of ±0.01 mm for the through hole 11 of the head 1. The pin portion 2 uses a wire drawing process to draw out a whole roll of stainless steel wire with accurate diameter, and the tolerance can reach ±0.003 mm, so the headed pin has a very high precision.

[0047] See also Figure 8 and Fig. 9 As shown, the head pin can be used to assemble a miniature biopsy forceps 5, which includes a single-strand drive cable 51, two drive connecting rods 52, two clamps 53, a clamp head frame 54 and a flexible sleeve 55, a pin shaft 56 and two head pins 57.

[0048] One end of the two driving links 52 is pivotally connected to the driving end 511 of the single-strand driving cable 51. One end of the two driving links 52 is provided with a second pivot hole 521, and the pin 56 passes through the first pivot hole 512 of the driving end 511 and the second pivot hole 521 of the two driving links 52, so that the two driving links 52 are pivotally connected to the driving end 511. The other end of the two driving links 52 is provided with a third pivot hole 522.

[0049] The two jaws 53 are respectively pivotally connected to the other ends of the two driving links 52, so that the two jaws 53 can be pivotally opened or closed by the operation of the driving links 52. The two jaws 53 are each provided with a fourth pivot hole 531, and the head pin 57 passes through the third pivot hole 522 and the fourth pivot hole 531, and the two jaws 53 are respectively pivotally connected to the other ends of the two driving links 52, thereby, the two jaws 53 are opened or closed relative to the axis of the single strand driving cable 51.

[0050] The clamp head frame 54 is sleeved on the driving end 511 and connected to the clamp portion 53 by a pin 541, so that the clamp head frame 54 can support the clamp portion 53 and be used to install the driving link 52. The flexible sleeve 55 is sleeved on the single-strand driving cable 51 and smoothly adjacent to the clamp head frame 54. The clamp head frame 54 and the flexible sleeve 55 are completely sleeved outside the single-strand driving cable 51, so that the single-strand driving cable 51 can be prevented from being damaged by collision and bending and deformation.

[0051] The pin portion 571 of the head pin 57 is mainly utilized. After passing through the third pivot hole 522 of the two driving links 52 and the fourth pivot hole 531 of the two jaws 53, it is welded and fixed, so as to fix the two jaws 53 and the two driving links 52 together to form a four-bar linkage structure, and then assembled into a biopsy forceps 5.

[0052] In this way, the biopsy forceps assembled together with the headed pin manufactured by the embodiment of the present invention can be used for a long time without losing accuracy or being damaged because the headed pin has accurate size and excellent maneuverability, and the risk of parts slipping off is small due to its large head.

[0053] See also Fig.10 As shown, another embodiment of the present invention includes the following steps:

[0054] A. A head is formed by a stamping process, and the head has a through hole;

[0055] B. A pin portion having a round rod shape is formed by a wire drawing process, wherein the diameter of the pin portion is smaller than the inner diameter of the through hole;

[0056] C. One end of the pin is placed in a limiting hole of a welding fixture, so that the other end of the pin protrudes out of the welding fixture to become a fixed end, and the length of the fixed end and the thickness error of the head are +0.08 to -0.01mm;

[0057] D. The through hole of the head is fitted onto the fixed end, and a welding process is applied to the head and the fixed end to fix the head to the fixed end, thereby manufacturing a headed pin.

[0058] Another embodiment of the present invention is different from the above embodiment only in that the support member is not required, and the head pin can be easily manufactured at low cost and with high precision.

[0059] Based on the description of the above embodiments, one should be able to fully understand the operation, use and effects of the present invention. The above embodiments are only preferred embodiments of the present invention and should not be used to limit the scope of implementation of the present invention. That is, all simple equivalent changes and modifications made based on the contents of the present invention are within the scope of the present invention.

Claims

1. A method for manufacturing a headed pin of a biopsy forceps, characterized in that: It includes the following steps: A head is formed by a stamping process, and a through hole is formed on the head; A pin portion is formed by a wire drawing process, wherein the diameter of the pin portion is smaller than the inner diameter of the through hole; One end of the pin is placed in a limiting hole of a welding fixture, so that the other end of the pin protrudes out of the welding fixture to become a fixed end, and the length of the fixed end and the thickness error of the head are +0.08 to -0.01 mm; The through hole of the head is sleeved on the fixed end, and a welding process is applied to the head and the fixed end to fix the head on the fixed end, so as to manufacture a headed pin.

2. The method for manufacturing a headed pin of a biopsy forceps according to claim 1, characterized in that: The head is in a circular ring shape, and the pin is in a round rod shape.

3. The method for manufacturing a headed pin of a biopsy forceps according to claim 1, characterized in that: The punching process is to put a blank between a male mold and a female mold of a punching mold, and to manufacture the head with the through hole in an integrated manner through continuous punching.

4. The method for manufacturing a headed pin of a biopsy forceps according to claim 1, characterized in that: The outer diameter of the head is 0.44-0.5 mm, the thickness of the head is 0.1-0.15 mm, the inner diameter of the through hole is 0.25-0.35 mm, and the diameter of the pin is 0.25-0.35 mm.

5. The method for manufacturing a headed pin of a biopsy forceps according to claim 1, characterized in that: The surface of the welding fixture has a working plane, on which one or more limiting holes are arranged, and the depth of the limiting holes is less than the sum of the length of the pin portion and the thickness of the head portion.

6. The method for manufacturing a headed pin of a biopsy forceps according to claim 5, characterized in that: The depth of the limiting hole is 4.88 mm, and the length of the fixed end is 0.1-0.15 mm.

7. The method for manufacturing a headed pin of a biopsy forceps according to claim 5, characterized in that: Two vertically opposite side surfaces of the welding fixture are communicated with each other and are provided with a slot penetrating to a position below the limiting hole.

8. The method for manufacturing a headed pin of a biopsy forceps according to claim 1, characterized in that: The welding process is performed on the head and the fixing end by using a welding device, and the welding device is a laser welding machine, a spot welding machine, an electron beam welding machine or a plasma welding machine.

9. The method for manufacturing a headed pin of a biopsy forceps according to claim 1, characterized in that: The head is integrally formed and connected with a support piece in a transverse direction. After the through hole of the head is sleeved on the fixed end, the support piece is fixed and then the welding process is performed. After the welding is completed, the support piece of the head is removed.

10. The method for manufacturing a headed pin of a biopsy forceps according to claim 9, characterized in that: The punching process is to put a blank between a male mold and a female mold of a punching mold, and to manufacture the head with the through hole and the support member in an integrated manner through continuous punching.

11. The method for manufacturing a headed pin of a biopsy forceps according to claim 9, characterized in that: The length of the support member is 5.8 mm, and the thickness of the support member is 0.12 mm.

12. The method for manufacturing a headed pin of a biopsy forceps according to claim 9, characterized in that: The support is fixed by a clamp or a jig manually or automatically to prevent the head from shaking.

13. The method for manufacturing a headed pin of a biopsy forceps according to claim 9, characterized in that: The support to which the head is attached is removed using pliers and a grinding device.

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