Wire cutters

Abstract

The present invention relates to a wire cutter, comprising: an outer shear with an outer shear edge at the distal end; a control body, an inner shear, the inner shear including a functional part and an inner core, the inner core being slidably disposed within the outer shear, the distal end of the inner core being connected to the proximal end of the functional part, the proximal end of the inner core being connected to the control body, the inner core being configured to drive the functional part and the outer shear to move axially relative to each other under the traction of the control body, wherein an inlet is provided on the distal end face of the functional part, an outlet is provided on the side wall of the functional part, the outlet is communicated with the inlet through a wire passing hole, and an inner shear edge capable of cooperating with the outer shear edge is provided at the distal end of the outlet; wherein, the material of the distal end of the outer shear is 455 stainless steel, the material of the functional part is 420 stainless steel, and the fitting clearance between the functional part and the outer shear is not greater than 0.06 mm, with good wire cutting effect and longer wire cutting service life.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a wire cutting pliers. Background Art

[0002] In endoscopic surgical suture tools, wire cutting pliers are required to cut surgical suture threads. The service life of surgical scissors is affected by the cutting edge. After cutting a certain number of times, the edge wears out, and wire drawing is likely to occur, and even the suture thread cannot be effectively cut. At present, it is required that the wire cutting pliers can cut the wire continuously, and the number of wire cutting times reaches more than 10,000 times. However, in fact, wire drawing occurs when the wire cutting pliers cut the wire 2,000 times, and the edge is completely damaged when the wire cutting times reach 3,000 times, and the suture thread cannot be cut, and the function fails. Summary of the Invention

[0003] Based on this, it is necessary to propose a wire cutting pliers for the problem that the number of wire cutting times in the prior art cannot meet the requirements, that is, the function fails.

[0004] A wire cutting pliers, comprising: an outer shear, the distal end of the outer shear is provided with an outer shear edge; a control body, arranged at the proximal end of the outer shear, an inner shear, the inner shear includes a functional part and an inner core, the inner core is slidably arranged in the outer shear, the distal end of the inner core is connected to the proximal end of the functional part, the proximal end of the inner core is connected to the control body, the inner core is used to drive the functional part and the outer shear to move axially relative to each other under the traction of the control body, wherein an inlet is provided on the distal end surface of the functional part, an outlet is provided on the side wall of the functional part, the outlet is communicated with the inlet through a wire passing hole, and an inner shear edge capable of cooperating with the outer shear edge is provided at the distal end of the outlet; wherein, the material of the distal end of the outer shear is 455 stainless steel, the material of the functional part is 420 stainless steel, and the fitting clearance between the functional part and the outer shear is not greater than 0.06 mm.

[0005] For the above-mentioned wire cutting pliers, 455 stainless steel has high strength and good corrosion resistance, 420 stainless steel has certain wear resistance and corrosion resistance and relatively high hardness. The hardness of 455 stainless steel is not as high as that of 420 stainless steel. When cooperating with 420 stainless steel, there will be no phenomenon of "hard" hitting "hard", but "soft" and "hard" cooperation, so the wire cutting effect can be better exerted. 420 stainless steel is used as the material of the functional part of the inner shear, with high hardness, and it is easier to cut the surgical thread during the wire cutting process, and it is more wear-resistant than 455 stainless steel. When the fitting clearance is controlled not to be greater than 0.06 mm, it is ensured that the suture thread can be cut at one time, and at the same time, the phenomenon of incomplete cutting at one time and increased wear due to too large a clearance is avoided, so that more wire cutting times can be achieved.

[0006] In one embodiment, the fitting clearance range between the functional part and the outer shear is 0.02 mm - 0.06 mm.

[0007] In one embodiment, the inlet port is inclined away from the outlet port along a direction towards the proximal end.

[0008] In one embodiment, the wire threading hole gradually contracts from the inlet port to the outlet port.

[0009] In one embodiment, the wire threading hole is a tapered hole.

[0010] In one embodiment, the fitting clearance between the inner core and the outer shear is greater than the fitting clearance between the functional part and the outer shear.

[0011] In one embodiment, the transition surface between the functional part and the inner core is an arc surface.

[0012] In one embodiment, the inner core is offset away from the outlet port relative to the functional part.

[0013] In one embodiment, the functional part and the outer shear both extend along a first axis, and the inner core extends along a second axis, and the second axis is not collinear with the first axis.

[0014] In one embodiment, the second axis deviates from the first axis by 2 - 4°. Description of the Drawings

[0015] Figure 1 It is a schematic structural diagram of a wire cutting pliers in a use state of an embodiment.

[0016] Figure 2 It is Figure 1 a top view of

[0017] Figure 3 It is Figure 1 a schematic assembly structure diagram of the inner shear and the outer shear of the wire cutting pliers in one direction.

[0018] Figure 4 It is a partial schematic diagram of the assembly structure of the inner shear and the outer shear in another direction.

[0019] Figure 5 It is a partial sectional structural schematic diagram of the assembly structure of the inner shear and the outer shear.

[0020] Figure 6 It is a schematic structural diagram of the functional part of the inner shear.

[0021] The corresponding numbers of the related elements in the figure are as follows:

[0022] 100, Wire Cutter; 10, Outer Shear; 110, First Pin Hole; 120, Outer Shear Edge; 20, Inner Shear; 210, Functional Part; 211, Inlet; 212, Outlet; 213, Threading Hole; 214, Inner Shear Edge; 220, Inner Core; 221, Second Pin Hole; 230, Transition Surface; 30, Control Body; 310, Fixed Handle; 320, Movable Handle; 330, Control Switch; 340, Link; X, First Axis; Y, Second Axis; 200, Suture Thread. Detailed Embodiment

[0023] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following detailed description of the specific embodiments of the present invention will be given in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axis", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0025] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0026] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the present invention, for the sake of easy understanding, terms such as "proximal end" and "distal end" are used, which refer to the relative orientation, relative position, and direction of elements or actions relative to each other from the perspective of a doctor using the medical device. The "proximal end" and "distal end" are not restrictive, but the "proximal end" generally refers to the end of the medical device that is close to the operator during normal operation, while the "distal end" generally refers to the end that is far from the operator.

[0028] In the art, traditional surgical suture scissors often make the inner scissors and the outer scissors move relative to each other to cut the surgical suture. However, the service life of the suture scissors is affected by the cutting edges. Before reaching the required number of suture cutting times of 10,000 times, the cutting function often fails, resulting in the inability to effectively cut the suture, or even complete failure to cut the suture.

[0029] To solve the problem of failure due to insufficient suture cutting times, the applicant has found through research that materials with higher hardness and wear resistance can be selected to improve the wear resistance of the inner scissors and the outer scissors. Usually, 420 stainless steel, which is commonly used in surgical instruments, is selected for the inner scissors and the outer scissors. 420 stainless steel has high hardness and wear resistance and is more likely to cut the suture during the suture cutting process. However, when 420 stainless steel is used for the inner scissors and the outer scissors, the applicant has found that such suture scissors have good effects in the early stage of use, and the one-time cutting effect is relatively ideal. However, as the number of uses increases, the wear of the outer cutting edge of the outer scissors and the inner cutting edge of the inner scissors increases significantly, and the cutting ability of the suture scissors decreases rapidly, resulting in the still inability to meet the requirements of the number of suture cutting times well. In addition, the phenomenon of the exposed outer scissors being bruised also increases.

[0030] Based on the above considerations, in order to solve the problem that the design of selecting 420 stainless steel for the inner scissors and the outer scissors due to insufficient suture cutting times leads to increased wear and thus fails to effectively solve the problem of insufficient suture cutting times, as well as the problem that the outer scissors are prone to being bruised, the inventor has conducted in-depth research and proposed a pair of suture scissors. The functional part of the inner scissors is made of 420 stainless steel, and at least the area of the outer scissors that cooperates with the functional part (i.e., the distal end of the outer scissors) is made of 455 stainless steel. At the same time, the cooperation gap between the outer scissors and the functional part is controlled to be no more than 0.06 mm.

[0031] In such wire cutters, the wire cutting effect is good and the service life of wire cutting is longer. Specifically, 455 stainless steel is maraging stainless steel, which has high strength and good corrosion resistance. 420 stainless steel has certain wear resistance and corrosion resistance, and has a relatively high hardness, belonging to "cutting tool grade" martensitic steel. Considering the requirements for material strength and corrosion resistance in the air, both materials have good cutting ability as the inner cutting edge. After annealing, 455 stainless steel has good elastic properties and is not easily bruised. As the outer cutter, it is not easily bruised. The hardness of 455 stainless steel is not as high as that of 420 stainless steel. When combined with 420 stainless steel, there will be no phenomenon of "hard" hitting "hard", but "soft" and "hard" cooperation, so it can reduce wear and better play the wire cutting effect. 420 stainless steel is used as the material of the functional part of the inner cutter. It has a high hardness, is easier to cut the surgical suture during wire cutting, and is more wear-resistant than 455 stainless steel. When the fit clearance is controlled not to be greater than 0.06 mm, it is ensured that the suture can be cut off at one time, and at the same time, the phenomenon of increased wear caused by the inability to cut off at one time when the clearance is too large can be avoided, so that more wire cutting times can be achieved.

[0032] The following will describe in detail the wire cutters according to the embodiments of the present invention with reference to the accompanying drawings.

[0033] As Figure 1 and Figure 2 shown, an embodiment of the present invention provides a wire cutter 100, which can be used to cut off a suture 200 after completing an endoscopic suture operation (such as a rotator cuff suture operation at the shoulder joint). The wire cutter 100 according to the embodiment of the present invention includes an outer cutter 10, an inner cutter 20, and a control body 30. The outer cutter 10 is sleeved outside the inner cutter 20. The inner cutter 20 is slidably arranged relative to the outer cutter 10 for threading the suture 200. The control body 30 is installed at the proximal end of the outer cutter 10 and is connected to the inner cutter 20. The control body 30 is used to pull the inner cutter 20 to move relative to the outer cutter 10, so that the inner cutter 20 can cooperate with the outer cutter 10 to cut off the suture 200. Figures 1 to 3 In

[0034] The outer cutter 10 is specifically in the shape of a hollow cylinder, and its outer surface is smooth. On the one hand, it can be conveniently processed based on a bar stock. On the other hand, it is not easy to damage human tissues during operation in the human body. Of course, the outer cutter 10 is not limited to a cylinder. For example, it can also be a polygon with a smooth transition between adjacent sides of the polygon. As Figure 3 shown, a first pin hole 110 is provided at the proximal end of the outer cutter 10. The first pin hole 110 is used to connect to the control body 30 through a pin. At least the distal end of the outer cutter 10 is made of 455 stainless steel. Preferably, the entire outer cutter 10 is made of 455 stainless steel, which is convenient for processing.

[0035] The control body 30 is arranged at the proximal end of the outer shear 10 and is connected to the inner shear 20. The specific structure of the control body 30 is not limited, as long as it can traction the inner shear 20 to move relative to the outer shear 10. Combining Figures 1 to 3 As shown, in one example, the control body 30 includes a fixed handle 310, a movable handle 320, a control switch 330 and a connecting rod 340. The fixed handle 310 is connected to the first pin hole 110. The movable handle 320 is hinged to the fixed handle 310 and is connected to the second pin hole 221 on the inner shear 20 through the connecting rod 340. The control switch 330 is used to drive the movable handle 320 to rotate and then drive the inner shear 20 to perform a reciprocating linear motion. For another example, in other embodiments, the control body 30 can also be a sliding mechanism arranged at the proximal end of the outer shear 10.

[0036] As Figures 3 to 6 shown, the inner shear 20 includes a functional part 210 and an inner core 220. The distal end of the inner core 220 is connected to the proximal end of the functional part 210. As Figure 3 shown, the proximal end of the inner core 220 is provided with a second pin hole 221 for connection with the control body 30. Figures 1 to 3 In this case, the proximal ends of the inner shear 20, the functional part 210 and the inner core 220 are their respective right ends, and the distal ends are their respective left ends. The inner shear 20 is specifically rod-shaped and is not easy to damage human tissues when operating in the human body, but it is not limited to this shape. The inner core 220 is arranged inside the outer shear 10 and drives the functional part 210 to move relative to the outer shear 10 under the traction of the control body 30. When the functional part 210 moves to overlap with the outer shear 10, the functional part 210 and the outer shear 10 cooperate to cut the suture 200 together. As Figure 5 and Figure 6 shown, an inlet 211 is provided on the distal end surface of the functional part 210, and an outlet 212 is provided on the side wall of the functional part 210. The outlet 212 is communicated with the inlet 211 through a threading hole 213. Specifically, if the functional part 210 is generally cylindrical, the distal end surface is the bottom surface of the cylinder, and the side wall is the side surface of the cylinder. If the functional part 210 is of other shapes, the relative positions of the inlet 211 and the outlet 212 can be deduced by analogy.

[0037] Specifically, when using the wire cutter 100 for wire cutting operation: As Figure 5 and Figure 6 shown, the suture 200 is made to enter the threading hole 213 from the inlet 211 and extend out of the functional part 210 from the outlet 212 to complete threading. Then, the control switch 330 is used to drive the movable handle 320 to rotate, so that the inner shear 20 moves backward ( Figure 1 to the right in this case), so that the end of the outlet 212 away from the inner core 220 and the outer shear 10 cut the suture 200 through shearing action, that is, the wire cutting operation is completed.

[0038] At least the material of the functional part 210 on the inner scissors 20 is 420 stainless steel. Preferably, the whole inner scissors 20 are made of 420 stainless steel, which is convenient for processing. The fitting clearance between the functional part 210 and the distal end of the outer scissors 10 is not greater than 0.06 mm. Preferably, the fitting clearance range between the functional part 210 and the outer scissors 10 is 0.02 mm - 0.06 mm. More preferably, the fitting clearance between the functional part 210 and the outer scissors 10 is 0.04 mm. When the fitting clearance range is 0.02 mm - 0.06 mm, it not only ensures the wire cutting ability but also takes into account the processing ability, that is, the requirement for processing accuracy can be appropriately reduced.

[0039] In order to better cut the suture 200, in combination with Figure 4 and Figure 6 As shown, at one end of the wire outlet 212 on the functional part 210 of the inner scissors 20 away from the inner core 220, there is an inner cutting edge 214. Correspondingly, at the distal end of the outer scissors 10, there is an outer cutting edge 120 that can cooperate with the inner cutting edge 214. Both the inner cutting edge 214 and the outer cutting edge 120 are relatively sharp, which is beneficial to cutting the suture 200. In a specific embodiment, the wire outlet 212 is triangular, and the inner cutting edge 214 on the inner scissors 20 is triangular. One vertex and two sides of the wire outlet 212 on the left are processed into sharp blade shapes to obtain the inner cutting edge 214. The outer cutting edge 120 on the outer scissors 10 is the edge position of the distal end of the outer scissors 10 close to the wire outlet 212, which is processed into a sharp blade shape to obtain the cutting edge. During specific processing, the inner cutting edge 214 on the inner scissors 20 can be processed by slow wire cutting the blade, and then finely polished, so that the surface roughness is small. The outer cutting edge 120 on the outer scissors 10 can be formed into a blade by using a grinding machine. The outer cutting edge 120 formed by grinding the blade on the grinding machine is sharper, without notches under microscopic view, and has good shearing ability.

[0040] When using the wire cutting pliers 100 for wire cutting operation, the suture 200 enters the wire threading hole 213 from the wire inlet 211 and extends out of the functional part 210 from the wire outlet 212. The wire threading can only be along the direction parallel to the functional part 210, but this is relatively difficult for endoscopic surgery due to space limitations.

[0041] For this reason, in one embodiment, in combination with Figure 5 and Figure 6As shown, the inlet 211 is inclined towards the proximal end of the inner core 220 and the side of the functional part 210 away from the outlet 212, making it more convenient to thread the suture 200. Specifically, the outlet 212 is provided at the top of the functional part 210, and the inlet 211 is provided in the lower region of the distal end face of the functional part 210, and this lower region is inclined towards the proximal end of the right inner core 220 and the bottom of the functional part 210. In this way, originally the suture could only be threaded along the direction parallel to the functional part 210 from the left side of the functional part 210, but after improvement, in addition to still being able to thread along the direction parallel to the functional part 210 from the left side of the functional part 210, it can also be threaded from the lower left of the functional part 210, making it more convenient to thread during the surgical operation.

[0042] In one embodiment, from the inlet 211 to the outlet 212, the threading hole 213 gradually contracts. Specifically, the threading hole 213 is a tapered hole, and the taper is 1°, but it is not limited to this. During manufacturing, the threading hole 213 can be processed by slow wire cutting and swinging the wire by 1°. In this way, the entrance size of the threading hole 213 is larger, making it easy for the suture 200 to penetrate; the rear section of the threading hole 213 gradually becomes narrower, which can guide the penetrated suture 200 and make it easy for the suture to pass through. Therefore, the structural design of the gradually contracting threading hole 213 is beneficial to the penetration and passing of the suture.

[0043] In one embodiment, the fitting clearance between the inner core 220 and the outer scissors 10 is greater than the fitting clearance between the functional part 210 and the outer scissors 10. And the length of the inner core 220 is greater than the length of the functional part 210. In this way, most of the inner scissors 20 will not rub against the outer cutting edge 120 of the outer scissors 10, which is beneficial to extending the service life of the inner cutting edge 214.

[0044] Specifically, the diameter of the functional part 210 is greater than the diameter of the inner core 220. That is, in comparison, the functional part 210 is thick and the inner core 220 is thin. In this way, when the inner scissors 20 slide relative to the outer scissors 10, most of the time the inner scissors 20 do not rub against the outer cutting edge 120 of the outer scissors 10, which is beneficial to extending the service life of the outer cutting edge 120 of the outer scissors 10.

[0045] Furthermore, the transition surface 230 between the functional part 210 and the inner core 220 is an arc surface. In this way, there is a smooth transition between the functional part 210 and the inner core 220. When the inner scissors 20 slide relative to the outer scissors 10 to cut the thread more smoothly, when the functional part 210 moves backward to cooperate with the outer scissors 10, the transition surface 230 is not easy to damage the outer cutting edge 120 of the outer scissors 10.

[0046] Such as Figure 5 and Figure 6As shown, the inner core 220 is offset towards the side of the functional part 210 away from the wire outlet 212. Here, the side refers to one of the two radially opposite sides. Specifically, both the functional part 210 and the outer shear 10 extend along the first axis X, and the inner core 220 extends along the second axis Y. The second axis Y and the first axis X are not on the same straight line. For example, an obtuse angle is formed between the inner core 220 and the functional part 210. In a specific embodiment, during manufacturing, the junction between the inner core 220 and the functional part 210 can be bent by a special tooling, so that the whole inner core 220 deviates from the horizontal line by 2-4° (i.e., the included angle between the first axis X and the second axis Y is 2-4°), preferably 3°. In this way, the inner core 220 and the functional part 210 are still nearly straight, which does not affect the smooth sliding of the inner shear 10, but forms the effect that the inner core 220 is further away from the side of the wire outlet 212. When cutting the wire, the surface of the inner core 220 is not easily scratched during internal friction, and the outer shear edge 120 of the outer shear 10 is not easily damaged. It is easy to understand that the second axis Y and the first axis X can also be parallel to each other, but the second axis Y is translated towards the side away from the wire outlet 212 relative to the first axis X. In this way, it also does not affect the smooth sliding of the inner shear 10, but forms the effect that the inner core 220 is further away from the side of the wire outlet 212.

[0047] In addition, through the above structural design, most of the area of the inner shear 20 does not rub against the outer shear edge 120 of the outer shear 10. The wire cutting pliers 100 can further reduce the fitting clearance between the outer shear 10 and the functional part 210 of the inner shear 20, so as to increase the shearing force and the operating feeling of wire cutting is better.

[0048] Specifically, during actual manufacturing, due to inevitable error causes resulting from processing accuracy, the smaller the fit clearance, the more likely it is that the inner cutting edge 214 of the inner shear 20 and the outer cutting edge 120 of the outer shear 10 will rub against each other when the functional part 210 of the inner shear overlaps with the outer shear 10. If the diameter of the inner core 220 is the same as the diameter of the functional part 210, when the inner cutting edge 214 of the inner shear 20 rubs against the outer cutting edge 120 of the outer shear 10, when the inner core 220 slides relative to the outer shear 10, the inner core 220 will also rub against the outer cutting edge 120 of the outer shear 10. That is to say, this will cause the inner core 220, which is not used to perform the wire cutting function, to also rub against the outer cutting edge 120 of the outer shear 10 when the inner shear 20 slides relative to the outer shear 10, resulting in the phenomenon that the inner shear 20 always rubs against the outer cutting edge 120 of the outer shear 10 when it slides, which will greatly reduce the service life of the outer cutting edge 120 of the outer shear 10. With the above structural design, most areas of the inner shear 20 do not rub against the outer cutting edge 120 of the outer shear 10, so it is beneficial to minimize the fit clearance between the outer shear 10 and the functional part 210 of the inner shear as much as possible. In this way, even if the inner cutting edge 214 of the inner shear 20 rubs against the outer cutting edge 120 of the outer shear 10, the above-mentioned rubbing only occurs before and after wire cutting. Compared with the inner shear 20 always rubbing against the outer cutting edge 120 of the outer shear 10, it is obviously beneficial to extend the service life of the outer cutting edge 120 of the outer shear 10.

[0049] The advantages of the wire cutting pliers according to the embodiments of the present invention will be further described below in conjunction with multiple embodiments and comparative examples.

[0050] Experiment 1

[0051] The inner shear 20 and the outer shear 10 were made of different materials respectively, and the fit clearances were 0.04 mm and 0.1 mm respectively, and other structures were the same, and experiments were carried out. That is, continuous wire cutting was repeated until damage was found on the inner cutting edge 214 of the inner shear 20 or the outer cutting edge 120 of the outer shear 10 and wire cutting could not be performed, and the effective number of wire cutting times (each cut wire was counted as one time) was recorded as the evaluation criterion. The specific results are shown in Table 1.

[0052] Table 1

[0053] Group type Outer cutting material Inner cutting material Fitting clearance Number of cutting times 1 455 stainless steel 455 stainless steel 0.04 mm 3 thousand 2 420 stainless steel 420 stainless steel 0.04 mm 2 thousand 3 3 316 stainless steel 316 stainless steel 0.04 mm 1 thousand 9 4 455 stainless steel 455 stainless steel 0.1 mm 2 thousand 5 5 420 stainless steel 420 stainless steel 0.1 mm 2 thousand 1 6 316 stainless steel 316 stainless steel 0.1 mm 1 thousand 8 7 455 stainless steel 420 stainless steel 0.04 mm 10,000+ 8 455 stainless steel 420 stainless steel 0.1 mm 6,000+ 9 420 stainless steel 455 stainless steel 0.04 mm 7,000+

[0054] As can be seen from the above experimental results, in the seventh group of experimental data, for the external shear 10, 455 stainless steel is used, and for the internal shear 20, 420 stainless steel is used. The wire-cutting pliers with a mating clearance of 0.04 mm have a longer service life. Among them, the number of times the wire-cutting pliers with a mating clearance of 0.04 mm can cut the surgical thread at one time is significantly higher than that of the wire-cutting pliers with a mating clearance of 0.1 mm. This is because with a smaller mating clearance, the wire-cutting effect can be significantly improved, and the wire-cutting can often be successful at one time. However, due to the poor wire-cutting effect of the wire-cutting pliers with a mating clearance of 0.1 mm, sometimes it is necessary to cut several times to cut the suture, so it is damaged and unable to cut the wire when completing a small number of effective wire-cutting times.

[0055] In addition, on the basis of a mating clearance of 0.04 mm, the applicant also appropriately increased and decreased the mating clearance respectively, and also used different materials to make the external shear 10 and the internal shear 20 for experiments respectively. The experiments show that when the clearance is further reduced, the number of wire-cutting times shows an increasing trend.

[0056] For example, when the mating clearance is reduced from 0.04 mm to 0.02 mm, the number of wire-cutting times can increase by 1000 - 1500 times. At this time, except that the number of wire-cutting times can reach more than 10,000 times when the external shear 10 is made of 455 stainless steel and the internal shear 20 is made of 420 stainless steel, the number of wire-cutting times in other material cases still cannot meet the requirements.

[0057] For example, when the mating clearance is increased from 0.04 mm to 0.06 mm, the number of wire-cutting times decreases. In the seventh group of experiments, for the external shear 10, 455 stainless steel is used, and for the internal shear 20, 420 stainless steel is used. When the mating clearance is changed to 0.06 mm, the number of wire-cutting times is close to the critical point of 10,000 times. In other groups of experiments, the number of wire-cutting times decreases, and the number of wire-cutting times is even more unable to meet the requirements.

[0058] Experiment Two

[0059] Fix the materials of the external shear 10 and the internal shear 20 to be 455 stainless steel and 420 stainless steel respectively, change the mating clearance, the transition surface, and the included angle characteristics of the internal shear 20 itself, conduct experiments, and repeat continuous wire-cutting until damage is found on the internal shear edge 214 of the internal shear 20 or the external shear edge 120 of the external shear 10 and it is unable to cut the wire. Record the number of effective wire-cutting times (cutting the wire is recorded as once) as the evaluation criterion. The specific results are shown in Table 3.

[0060] Table 2

[0061]

[0062] In Experiment 2, the first group of data (effective wire cutting times) is significantly better than the other three groups of data. It can be seen that the wire cutting effect of the wire cutters in the embodiments of the present invention is better and the service life is longer. This is because when wire cutting is performed with a structure having a larger fit clearance (Group 4), the phenomenon that the surgical wire cannot be cut off at one time will occur earlier. In order to cut it off, the wire cutting needs to be repeated, and the service life of the outer cutting edge 120 will be greatly reduced. For Group 2 without a transition surface and Group 3 where the inner cutter 20 is a straight line, since the friction time between the outer cutter 10 and the inner cutter 20 is longer, the wear of the outer cutting edge 120 increases, and the overall service life is greatly reduced.

[0063] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0064] In the present invention, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0065] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation.

[0066] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it cannot be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A wire cutter, characterized in that, The wire cutter includes: An outer shear, with an outer shear edge at the distal end of the outer shear; A control body, arranged at the proximal end of the outer shear, An inner shear, the inner shear includes a functional part and an inner core, the inner core is slidably arranged inside the outer shear, the distal end of the inner core is connected to the proximal end of the functional part, the proximal end of the inner core is connected to the control body, the inner core is used to drive the functional part and the outer shear to make relative axial movement under the traction of the control body, wherein an inlet is provided on the distal end face of the functional part, an outlet is provided on the side wall of the functional part, the outlet is communicated with the inlet through a wire passing hole, and an inner shear edge capable of cooperating with the outer shear edge is provided at the distal end of the outlet; Wherein, the material of the distal end of the outer shear is 455 stainless steel, the material of the functional part is 420 stainless steel, and the clearance between the functional part and the outer shear is not greater than 0.06mm.

2. The wire cutter according to claim 1, wherein The clearance range between the functional part and the outer shear is 0.02mm - 0.06mm.

3. The wire cutter according to claim 1, characterized in that, The inlet slopes away from the outlet along the direction towards the proximal end.

4. The wire cutter according to claim 1, wherein From the inlet to the outlet, the wire passing hole gradually contracts.

5. The wire cutter according to claim 4, wherein, The wire passing hole is a tapered hole.

6. The wire cutter according to claim 1, characterized in that, The clearance between the inner core and the outer shear is greater than the clearance between the functional part and the outer shear.

7. The wire cutter according to claim 6, wherein The transition surface between the functional part and the inner core is an arc surface.

8. The wire cutter according to claim 1 or 6, characterized in that, The inner core is offset from the functional part towards the side away from the outlet.

9. The wire cutter according to claim 8, characterized in that, The functional part and the outer shear both extend along a first axis, the inner core extends along a second axis, and the second axis and the first axis are not on the same straight line.

10. The wire cutter according to claim 9, characterized in that, The second axis deviates from the first axis by 2 - 4°.

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