CN218960864U

CN218960864U - Medical cutting tool

Info

Publication number: CN218960864U
Application number: CN202223428347.5U
Authority: CN
Inventors: 郭毅军; 王永贤; 刘君
Original assignee: Chongqing Xishan Science and Technology Co Ltd
Current assignee: Chongqing Xishan Science and Technology Co Ltd
Priority date: 2022-12-21
Filing date: 2022-12-21
Publication date: 2023-05-05
Anticipated expiration: 2032-12-21

Abstract

The utility model relates to a medical cutting tool, comprising: an inner knife assembly and an outer knife assembly. The inner knife assembly includes an inner knife tube. The inner cutter pipe comprises a plurality of pipe sections which are sequentially arranged along the axial direction. One end of the pipe section is provided with a plurality of convex parts which are sequentially arranged at intervals around the circumferential direction, and the other end of the pipe section is provided with a plurality of concave parts which are sequentially arranged at intervals around the circumferential direction. For any two adjacent pipe sections, the convex parts of one pipe section are arranged in the concave parts of the other pipe section in a one-to-one correspondence. The outer knife assembly comprises an outer knife tube, and the inner knife tube is rotatably arranged in the outer knife tube in a penetrating manner. The inner cutter tube is synchronously bent to a required angle along any direction along with the outer cutter tube, and can transmit torque and reciprocate to shave or grind a focus area. In addition, the inner cutter pipe can be bent at will according to actual demands, so the inner cutter pipe is designed to be of a single-layer pipe structure, the product structure can be simplified, the processing and the manufacturing are convenient, and the cost is reduced.

Description

Medical cutting tool

Technical Field

The utility model relates to the technical field of medical instruments, in particular to a medical cutting tool.

Background

Medical cutting tools, including planing tools (abbreviated as planing tools) and medical cutting tools (abbreviated as grinding heads), are generally used in the operations of the ear cavities, the nasal cavities and the throat parts of the human body with more complex natural passages due to the small and exquisite structure and the bending capability. In the prior art, a medical cutting tool comprises an inner cutter assembly, wherein the inner cutter assembly comprises an inner cutter tube, a cutting head connected to the front end of the inner cutter tube and a first handle connected to the tail of the inner cutter tube; the cutting tool further comprises a sheath tube and a second handle connected with the sheath tube, and the inner cutter tube is rotatably arranged in the sheath tube and the second handle in a penetrating mode. However, because the curved inner cutter tube is formed by welding multiple layers of parts, each layer of parts is spiral, and two parts of each curved part are welded in multiple layers, the structure is complex, and the cost is high.

Disclosure of Invention

Based on the above, it is necessary to overcome the defects of the prior art, and to provide a medical cutting tool, which can simplify the product structure, facilitate processing and manufacturing, and reduce the cost.

The technical scheme is as follows: a medical cutting tool, the medical cutting tool comprising:

the inner cutter assembly comprises an inner cutter pipe, the inner cutter pipe comprises a plurality of pipe sections which are sequentially arranged along the axial direction, one end of each pipe section is provided with a plurality of convex parts which are sequentially arranged at intervals around the circumferential direction, and the other end of each pipe section is provided with a plurality of concave parts which are sequentially arranged at intervals around the circumferential direction; for any two adjacent pipe sections, the convex parts of one pipe section are correspondingly arranged in the concave parts of the other pipe section one by one; and

the outer cutter assembly comprises an outer cutter tube, and the inner cutter tube rotationally penetrates through the outer cutter tube.

In one embodiment, a plurality of convex portions are formed at one end nozzle edge of the pipe section and are sequentially spaced around the circumference, and a plurality of concave portions are formed at the other end nozzle edge of the pipe section and are sequentially spaced around the circumference.

In one embodiment, the convex portion is provided with a drop-preventing portion having a width that increases in a direction approaching the top wall of the convex portion, the concave portion is provided with a reduced-width portion having a width that decreases in a direction approaching the bottom wall of the concave portion, and the drop-preventing portion is provided in the reduced-width portion.

In one embodiment, the inner cutter tube is provided with at least one first bending part, and the first bending part is provided with a plurality of tube sections which are sequentially arranged along the axial direction; the outer cutter tube is provided with a second bending part corresponding to the first bending part.

In one embodiment, the inner cutter tube is obtained by cutting the inner cutter tube at a plurality of different positions.

In one embodiment, the convex portion is adapted to the shape of the concave portion, and a gap is provided between an outer wall of the convex portion and an inner wall of the concave portion.

In one embodiment, the medical cutting tool further comprises a flexible sleeve, the inner cutter tube is arranged in the flexible sleeve in a penetrating mode, and the flexible sleeve is tightly attached to the inner cutter tube.

In one embodiment, the inner cutter assembly further comprises an inner cutter head connected with the front end of the inner cutter tube; the outer cutter assembly further comprises an outer cutter head, the outer cutter head is connected with the front end of the outer cutter tube, and the inner cutter head rotationally penetrates through the outer cutter head.

In one embodiment, the inner cutter assembly further comprises a first handle body connected with the tail end of the inner cutter tube; the outer cutter assembly further comprises a second handle body, and the second handle body is connected with the tail end of the outer cutter tube; the second handle body is provided with a first channel communicated with the outer cutter tube, the inner cutter tube is arranged in the first channel in a penetrating mode, and the tail end of the inner cutter tube extends out of the second handle body.

In one embodiment, the second handle body is provided with a connecting nozzle communicated with the first channel; the medical cutting tool further comprises a sealing element and a pressing element, wherein the sealing element is arranged at one end of the first channel close to the first handle body, and the inner cutter tube is arranged in the sealing element in a penetrating manner; the compressing piece is sleeved outside the inner cutter tube and used for compressing and fixing the sealing piece on the second handle body.

In the medical cutting tool, the inner cutter tube comprises a plurality of tube sections which are sequentially arranged along the axial direction, and a plurality of convex parts of the tube sections are correspondingly arranged in a plurality of concave parts one by one for any two adjacent tube sections; in addition, the inner cutter tube is rotatably arranged in the outer cutter tube in a penetrating manner. Thus, the inner knife tube is a flexible piece, can be synchronously bent to a required angle along any direction along with the outer knife tube, and can transmit torque to carry out reciprocating motion to shave or grind a focus area. Compared with an inner cutter pipe formed by welding multiple layers of parts in the related art, the inner cutter pipe can be bent at will according to actual requirements, so that the inner cutter pipe is designed to be of a single-layer pipe structure, the product structure is simplified, the processing and the manufacturing are convenient, and the cost is reduced.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application, illustrate and explain the application and are not to be construed as limiting the application.

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a medical cutting tool according to an embodiment of the present utility model;

FIG. 2 is a schematic cross-sectional view of a medical cutting tool according to an embodiment of the present utility model;

FIG. 3 is an enlarged schematic view of FIG. 2 at A;

FIG. 4 is a schematic view of an inner cutter assembly according to an embodiment of the present utility model, wherein the first handle is omitted;

FIG. 5 is an enlarged schematic view of FIG. 4 at B;

fig. 6 is a schematic structural view of an inner cutter tube according to an embodiment of the present utility model after one of the tube sections is unfolded.

10. An inner cutter assembly; 11. an inner cutter tube; 111. a pipe section; 1111. a convex portion; 1112. a concave portion; 1113. an anti-falling part; 1114. a pinch portion; 115. a gap; 12. an inner cutter head; 13. a first handle body; 20. an outer cutter assembly; 21. an outer cutter tube; 22. an outer cutter head; 23. a second handle body; 231. a first channel; 232. a connecting nozzle; 30. a flexible sleeve; 40. a seal; 50. and a pressing member.

Detailed Description

In order to make the above objects, features and advantages of the present application more comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is, however, susceptible of embodiment in many other forms than those described herein and similar modifications can be made by those skilled in the art without departing from the spirit of the application, and therefore the application is not to be limited to the specific embodiments disclosed below.

Referring to fig. 1 to 2, fig. 1 shows a schematic structural view of a medical cutting tool according to an embodiment of the present utility model, and fig. 2 shows a schematic sectional structural view of a medical cutting tool according to an embodiment of the present utility model. An embodiment of the present application provides a medical cutting tool, the medical cutting tool includes: inner knife assembly 10 and outer knife assembly 20.

Referring to fig. 3 to 6, fig. 3 is an enlarged schematic view of fig. 2 at a, fig. 4 is a schematic view of an inner cutter assembly 10 according to an embodiment of the present utility model, in which the first handle 13 is omitted, fig. 5 is an enlarged schematic view of fig. 4 at B, and fig. 6 is a schematic view of an inner cutter tube 11 according to an embodiment of the present utility model after one of the tube sections 111 is unfolded. Wherein the inner cutter assembly 10 comprises an inner cutter tube 11. The inner cutter tube 11 includes a plurality of tube segments 111 arranged in sequence in the axial direction. One end of the pipe section 111 is provided with a plurality of protrusions 1111 sequentially spaced apart around the circumferential direction, and the other end of the pipe section 111 is provided with a plurality of recesses 1112 sequentially spaced apart around the circumferential direction. For any adjacent two pipe sections 111, the plurality of protrusions 1111 of one pipe section 111 are provided in the plurality of recesses 1112 of the other pipe section 111 in one-to-one correspondence. Further, the outer cutter assembly 20 includes an outer cutter tube 21, and the inner cutter tube 11 is rotatably inserted into the outer cutter tube 21.

In the medical cutting tool, since the inner cutter tube 11 includes a plurality of tube sections 111 sequentially arranged in the axial direction, and for any two adjacent tube sections 111, a plurality of protrusions 1111 of the tube section 111 are disposed in a plurality of recesses 1112 in a one-to-one correspondence; the inner cutter tube 11 is also rotatably inserted into the outer cutter tube 21. Thus, the inner cutter tube 11 is a flexible member, and can be synchronously bent to a required angle along any direction along with the outer cutter tube 21, and can transmit torque to reciprocate to shave or grind a focus area. Compared with the inner cutter tube 11 formed by welding multiple layers of parts in the related art, the inner cutter tube 11 can be bent at will according to actual requirements, so that the inner cutter tube 11 is designed to be of a single-layer tube structure, the product structure can be simplified, the processing and the manufacturing are convenient, and the cost is reduced.

It should be noted that, alternatively, the bending portion of the inner cutter tube 11 is a single-layer tube structure, and the thickness is flexibly adjusted and selected according to the actual requirement of the transmission torque.

In addition, the bending part of the inner cutter tube 11 has no welding position, so the bent cutter head has relatively short size (see L part in fig. 4), and can be bent at any place according to actual requirements, thereby meeting the requirements of different parts of patients. In addition, the number of the pipe sections 111 of the inner cutter pipe 11 per unit length can affect the radius of the inner cutter pipe 11 after bending, and when the number of the pipe sections 111 of the inner cutter pipe 11 per unit length is larger, the radius of the inner cutter pipe 11 after bending is smaller; conversely, when the number of tube sections 111 of the inner cutter tube 11 per unit length is smaller, the radius of the inner cutter tube 11 after bending is larger. Accordingly, the control of the size of the tube sections 111 is achieved by controlling the number of tube sections 111 per unit length, so that a curved shape satisfying different radius sizes can be achieved.

Referring to fig. 3, 5 and 6, in one embodiment, the protrusions 1111 have a width (as shown in the figuresW in 6 ₁ As shown) in a direction approaching the top wall of the boss 1111, the recess 1112 is provided with a width (as W in fig. 6) ₂ As shown) in the reduced-diameter portion 1114 which tends to decrease in the direction approaching the bottom wall of the recess 1112, the drop-off prevention portion 1113 is provided in the reduced-diameter portion 1114. Thus, after the two adjacent pipe sections 111 are assembled and connected with each other, the anti-falling part 1113 is arranged in the shrinkage part 1114, so that the limiting effect in the axial direction is achieved, the two adjacent pipe sections 111 can be prevented from being separated from each other in the axial direction, and are not easy to separate in the axial direction, and the stability of grinding work is ensured; in addition, since the inner cutter tube 11 is inserted into the outer cutter tube 21, the radial detachment phenomenon can be prevented.

It should be noted that the protrusions 1111 and the recesses 1112 may be separate components from the pipe section 111, such as a metal sheet welded to the pipe section 111; or may be a part of the pipe section 111, i.e. an integrally formed structure with the pipe section 111. The present embodiment is preferably an integrally formed structure, as shown in fig. 5 and 6, in which one end nozzle edge of the pipe section 111 is formed with a plurality of protrusions 1111 spaced apart in sequence around the circumferential direction, and in which the other end nozzle edge of the pipe section 111 is formed with a plurality of recesses 1112 spaced apart in sequence around the circumferential direction.

In one embodiment, after the pipe section 111 is unfolded, it can be observed that the head of the protrusion 1111 is large and the root is small, that is, the anti-drop portion 1113 and the necking portion 1114 in the above embodiment can be formed. The convex portion 1111 is formed in, for example, an arc, an elliptical arc, or a polygon, and the shape of the concave portion 1112 is adapted to the shape of the convex portion 1111.

In one embodiment, the inner cutter tube 11 is provided with at least one first bend. The first bending portion is provided with a plurality of tube segments 111 arranged in sequence in the axial direction. The outer cutter tube 21 is provided with a second bent portion corresponding to the first bent portion. In the actual operation process, when the second bending portion of the outer cutter tube 21 is bent, the first bending portion can be correspondingly driven to bend. Because the first bending part is provided with a plurality of pipe sections 111 which are sequentially arranged along the axial direction, the first bending part can flexibly bend and adjust the angle along with the second bending part when being stressed.

In a specific embodiment, the outer cutter tube 21 may be a plurality of tube sections 111, each of which is formed as a curved member, and the inner cutter tube 11 may be formed as a plurality of tube sections 111, each of which is formed as a plurality of tube sections.

In one embodiment, the inner cutter tube 11 is cut at a plurality of different locations to obtain a plurality of tube segments 111.

Specifically, for example, a plurality of different portions of the inner tube 11 are cut by a laser or plasma processing technique to form a plurality of cutting slits, thereby obtaining a plurality of tube segments 111 that are sequentially arranged in the axial direction.

Referring to fig. 3, 5 and 6, in one embodiment, the shape of the protrusion 1111 and the recess 1112 are adapted, and a gap 115 is formed between the outer wall of the protrusion 1111 and the inner wall of the recess 1112. The size of the gap 115 is controlled to be within 0.04mm-0.20mm, for example, and can be flexibly adjusted to other ranges according to actual requirements.

Referring to fig. 3, in one embodiment, the medical cutting tool further comprises a flexible sleeve 30. The inner cutter tube 11 is arranged in the flexible sleeve 30 in a penetrating way, and the flexible sleeve 30 is tightly attached to the inner cutter tube 11. In this way, the flexible sleeve 30 plays a role in sealing and isolating, prevents substances outside the inner cutter tube 11 from entering the inner cutter tube 11 through the gap 115 of the adjacent tube sections 111, and improves the safety of the operation.

Referring to fig. 2, in one embodiment, the inner cutter assembly 10 further includes an inner cutter head 12, and the inner cutter head 12 is connected to the front end of the inner cutter tube 11. The outer cutter assembly 20 further includes an outer cutter 22, the outer cutter 22 being connected to the front end of the outer cutter tube 21, and the inner cutter 12 rotatably passing through the outer cutter 22. In this embodiment, the inner cutter head 12 and the outer cutter head 22 may be matched to form a planing cutter head (i.e. planing tool) as shown, however, the inner cutter head 12 may also be a separate grinding cutter head (i.e. grinding head), which is not limited herein. Wherein, because the inner cutter tube 11 is provided with a plurality of tube sections 111 which are sequentially arranged along the axial direction, namely, the front end of the inner cutter tube 11 is relatively short, the requirements of different parts of a patient can be met, and the operation of doctors is convenient.

Referring to fig. 2, in one embodiment, the inner cutter assembly 10 further includes a first handle 13, and the first handle 13 is connected to the tail end of the inner cutter tube 11. The outer cutter assembly 20 further includes a second shank 23, the second shank 23 being connected to the trailing end of the outer cutter tube 21. The second handle body 23 is provided with a first channel 231 communicated with the outer cutter tube 21, the inner cutter tube 11 is arranged in the first channel 231 in a penetrating mode, and the tail end of the inner cutter tube 11 extends out of the second handle body 23.

Referring to fig. 2, in one embodiment, the second handle 23 is provided with a connection nozzle 232 in communication with the first channel 231. In addition, the medical cutting tool further comprises a sealing member 40 and a pressing member 50, wherein the sealing member 40 is arranged at one end of the first channel 231 close to the first handle body 13, and the inner cutter tube 11 is penetrated in the sealing member 40. The pressing member 50 is sleeved outside the inner cutter tube 11, and is used for pressing and fastening the sealing member 40 to the second handle body 23.

Specifically, the seal 40 is, for example, a gasket or a packing. Further, optionally, a step is provided on an inner wall of one end of the first passage 231 adjacent to the first shank 13, and the pressing member 50 abuts against the sealing member 40, so that the sealing member 40 is stably provided on the step. The sealing member 40 is closely contacted and matched with the outer wall of the inner cutter tube 11 penetrating through the inside of the sealing member to ensure the tightness of the first channel 231 and prevent the liquid in the first channel 231 from leaking outwards. Alternatively, the compression member 50 may include, but is not limited to, being fixedly coupled to the second shank 23 by threaded connection, snap fit, adhesive, or the like.

Referring to fig. 1 to 3, in one embodiment, a grinding device includes the medical cutting tool of any of the above embodiments, and further includes an endoscope having a second channel in which the medical cutting tool is inserted.

In the above-described grinding device, since the inner cutter tube 11 includes the plurality of tube segments 111 sequentially arranged in the axial direction, and for any two adjacent tube segments 111, the plurality of protrusions 1111 of the tube segment 111 are provided in the plurality of recesses 1112 in one-to-one correspondence; the inner cutter tube 11 is also rotatably inserted into the outer cutter tube 21. Thus, the inner cutter tube 11 is a flexible member, and can be synchronously bent to a required angle along any direction along with the outer cutter tube 21, and can transmit torque to reciprocate to shave or grind a focus area. Compared with the inner cutter tube 11 formed by welding multiple layers of parts in the related art, the inner cutter tube 11 can be bent at will according to actual requirements, so that the inner cutter tube 11 is designed to be of a single-layer tube structure, the product structure can be simplified, the processing and the manufacturing are convenient, and the cost is reduced.

It should be noted that, the "inner cutter head 12 and the first handle body 13" may be "a part of the inner cutter tube 11", that is, "the inner cutter head 12 and the first handle body 13" are manufactured integrally with "other parts of the inner cutter tube 11"; or can be a separate component which is separable from the other parts of the inner cutter tube 11, namely the inner cutter head 12 and the first handle body 13 can be manufactured independently and then combined with the other parts of the inner cutter tube 11 into a whole.

The "outer cutter head 22 and the second shank 23" may be "a part of the outer cutter tube 21", that is, the "outer cutter head 22 and the second shank 23" are integrally formed with "other parts of the outer cutter tube 21"; or can be a separate component which is separable from the other parts of the outer cutter tube 21, namely, the outer cutter head 22 and the second handle body 23 can be manufactured independently and then combined with the other parts of the outer cutter tube 21 into a whole.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the claims. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application is to be determined by the claims appended hereto.

In the description of the present application, 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," "axial," "radial," "circumferential," etc. indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be configured and operated in a particular orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless explicitly defined otherwise.

In this application, unless specifically stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

In this application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

Claims

1. A medical cutting tool, the medical cutting tool comprising:

2. The medical cutting tool according to claim 1, wherein one end nozzle edge of the tube segment is formed with a plurality of convex portions sequentially spaced around the circumference, and the other end nozzle edge of the tube segment is formed with a plurality of concave portions sequentially spaced around the circumference.

3. The medical cutting tool according to claim 1, wherein the convex portion is provided with a drop-preventing portion having a width that increases in a direction approaching the convex portion top wall, the concave portion is provided with a reduced-width portion having a width that decreases in a direction approaching the concave portion bottom wall, and the drop-preventing portion is provided in the reduced-width portion.

4. The medical cutting tool according to claim 1, wherein the inner cutter tube is provided with at least one first curved portion provided with a plurality of tube sections arranged in sequence in an axial direction; the outer cutter tube is provided with a second bending part corresponding to the first bending part.

5. The medical cutting tool according to claim 1, wherein the inner cutter tube is obtained by cutting at a plurality of different locations, respectively, to obtain the plurality of tube segments.

6. The medical cutting tool according to claim 1, wherein the convex portion conforms to the shape of the concave portion, and wherein the outer wall of the convex portion is provided with a gap with the inner wall of the concave portion.

7. The medical cutting tool of claim 1, further comprising a flexible sleeve, wherein the inner cutter tube is disposed through the flexible sleeve, and wherein the flexible sleeve is in close apposition with the inner cutter tube.

8. The medical cutting tool of claim 1, wherein the inner cutter assembly further comprises an inner cutter head, the inner cutter head being connected to the forward end of the inner cutter tube; the outer cutter assembly further comprises an outer cutter head, the outer cutter head is connected with the front end of the outer cutter tube, and the inner cutter head rotationally penetrates through the outer cutter head.

9. The medical cutting tool of claim 1, wherein the inner cutter assembly further comprises a first handle body coupled to the trailing end of the inner cutter tube; the outer cutter assembly further comprises a second handle body, and the second handle body is connected with the tail end of the outer cutter tube; the second handle body is provided with a first channel communicated with the outer cutter tube, the inner cutter tube is arranged in the first channel in a penetrating mode, and the tail end of the inner cutter tube extends out of the second handle body.

10. The medical cutting tool according to claim 9, wherein the second shank body is provided with a connecting nozzle in communication with the first channel; the medical cutting tool further comprises a sealing element and a pressing element, wherein the sealing element is arranged at one end of the first channel close to the first handle body, and the inner cutter tube is arranged in the sealing element in a penetrating manner; the compressing piece is sleeved outside the inner cutter tube and used for compressing and fixing the sealing piece on the second handle body.