CN111329546A

CN111329546A - Knob assembly and circular tube type anastomat

Info

Publication number: CN111329546A
Application number: CN201811549388.5A
Authority: CN
Inventors: 陈志�; 郭毅; 林江
Original assignee: Touchstone International Medical Science Co Ltd
Current assignee: Touchstone International Medical Science Co Ltd; Suzhou Tianchen International Medical Technology Co Ltd
Priority date: 2018-12-18
Filing date: 2018-12-18
Publication date: 2020-06-26

Abstract

The invention provides a knob assembly and a circular tube type anastomat, wherein the knob assembly comprises a knob driving piece and a knob body which are selectively linked, the knob body is sleeved outside a screw rod, and the screw rod is driven to move along the axial direction of the anastomat when the knob body rotates; set up one in first fitting piece and the second fitting piece on knob driving piece and the knob body respectively, first fitting piece is resilient fitting piece, and first fitting piece has and blocks the state and let the bit state, and when first fitting piece was in and blocks the state, first fitting piece and second fitting piece linkage, and when first fitting piece was in the bit state, first fitting piece did not link with the second fitting piece. By adopting the invention, when the knob driving piece is rotated, after the resistance borne by the knob body reaches the preset resistance value, the knob assembly can not transmit larger torque any more, and at the moment, the knob assembly enters a failure mode, and the gap between the nail anvil assembly and the nail bin is kept unchanged, so that tissues can not be excessively squeezed.

Description

Knob assembly and circular tube type anastomat

Technical Field

The invention relates to the technical field of medical instruments, in particular to a knob assembly and a circular tube type anastomat.

Background

Digestive tract diseases are one of the high-incidence diseases of human beings, and in the treatment process, a circular tube type anastomat is often used for performing anastomosis on physiological tissues such as the digestive tract instead of manual operation of a doctor. The circular tube type anastomat is a common surgical operation instrument, an axial internal stapling mode is mostly adopted, during operation, physiological tissues such as esophagus, stomach and intestinal tract are anastomosed end to end or end to side, two sections of tissues are contained in the anastomat in an inward converging mode during anastomosis, a circular anastomotic stoma is formed on the tissues after the anastomosis is finished, and a human body channel is rebuilt.

In the prior art, a circular tube-type anastomat comprises an anastomat body, an operating handle movably connected with the anastomat body and a nail anvil assembly matched with the anastomat body. The anastomat body comprises a nail bin assembly arranged at the far end, and the nail bin assembly comprises an annular nail bin and a cutter; and the knob is arranged at the near end of the body, the knob can rotate relative to the body, and the inside of the anastomat body also comprises an anvil shaft arranged from the near end to the far end. The distal and proximal ends are herein relative to the operator, with the end closer to the operator being the proximal end and the end further from the operator, i.e. closer to the surgical site, being the distal end. In the anastomat, the inner side and the outer side are relative to the axis of the anastomat, the side close to the axis is the inner side, and the side far away from the axis is the outer side. The nail anvil component comprises a nail anvil, a nail anvil cap arranged at the far end of the nail anvil and a knife anvil arranged in the nail anvil, and the nail anvil component can be directly connected with the far end of the nail anvil shaft or connected with the far end of the nail anvil shaft through a nail anvil shaft connecting piece. In the process of tumor operation, after tumor tissues are removed by separation, the nail anvil shaft penetrates out of the pouch of the residual end tissues and is arranged at the far end of the anastomat body, the knob is rotated to gradually reduce the distance between the nail anvil component and the nail bin to a proper distance, and then the nail anvil component and the nail bin reach a cockable state, and only the operating handle can be held to trigger the instrument to complete anastomosis. With the continuous development of medical instruments, the circular tube type anastomat is also widely applied to the treatment of diseases such as hemorrhoids and the like.

In the process of rotating the knob to enable the anvil component to approach the nail bin, sometimes, after the tissue is closed in place, the knob can still rotate, so that the anvil component and the nail bin can continuously approach to compress the tissue, the tissue is excessively squeezed, even the tissue can be crushed, and the operation result is very unfavorable.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a knob assembly and a circular tube type anastomat.

The embodiment of the invention provides a knob assembly which is used for a circular tube type anastomat, wherein a screw rod is arranged inside the anastomat; the knob assembly includes:

the knob body is sleeved outside the screw rod and drives the screw rod to move along the axial direction of the anastomat when rotating;

the first matching piece is an elastic matching piece and has a blocking state and a yielding state, when the first matching piece is in the blocking state, the first matching piece is linked with the second matching piece, and when the first matching piece is in the yielding state, the first matching piece is not linked with the second matching piece;

the first matching piece is arranged on the knob driving piece, and the second matching piece is arranged on the knob body; or, the first fitting piece is arranged on the knob body, and the second fitting piece is arranged on the knob driving piece.

Optionally, the knob driving piece is rotated by external force, and when the rotation resistance of the knob body is greater than a preset resistance value, the first fitting piece is deformed by the acting force of the second fitting piece to enter a yielding state.

Optionally, the first mating member is a spring plate with a protrusion.

Optionally, the knob driving member or the knob body is provided with a spring plate mounting groove, and two ends of the spring plate are mounted in the spring plate mounting groove.

Optionally, the resilient tab includes a first guide surface, and the first guide surface of the first mating member contacts the second mating member when the knob driver is rotated in the first direction.

Optionally, the first guide surface is a curved surface or a sloped surface.

Optionally, the resilient tab includes a second guide surface, and the second guide surface of the first mating member contacts the second mating member when the knob driver is rotated in the second direction.

Optionally, the second guide surface is a curved surface or a sloped surface.

Optionally, the second mating member comprises at least one mating structure, the mating structure being a protrusion or a groove.

Optionally, the engagement structure includes a first side surface, and when the knob driver rotates towards the first direction, the first side surface of the engagement structure contacts the first engagement member, and the first side surface inclines towards the first direction.

Optionally, the mating structure includes a second side surface, and the second side surface of the mating structure contacts the first mating member when the knob driver is rotated in the second direction.

Optionally, the second side surface of the mating structure is a right-angle surface, or the second side surface of the mating structure is inclined toward the second direction, and the inclination degree of the second side surface of the mating structure is smaller than the inclination degree of the first side surface of the mating structure.

Optionally, the knob driver comprises a knob housing, and the first mating member or the second mating member is disposed on an inner side surface of the knob driver.

Optionally, a first boss is disposed on an outer side surface of the knob body, the first fitting member is disposed on an inner side surface of the knob housing, and the second fitting member is disposed on a proximal end side or a distal end side of the boss; or

The second fitting member is disposed on an inner side surface of the knob housing, and the first fitting member is disposed on a proximal end side or a distal end side of the boss.

Optionally, a second boss is further disposed on the outer side surface of the knob body, and the second boss is located on the proximal end side of the first boss;

the first matching piece or the second matching piece is arranged on the second boss, the height of the first matching piece or the second matching piece of the second boss is lower than that of the first boss, and the far end of the knob body is matched with the first boss.

Optionally, the knob body further comprises a knob rear cover located at the proximal end of the knob body, a rear cover internal thread is arranged at the distal end of the knob rear cover, and a body external thread matched with the rear cover internal thread is arranged at the proximal end of the knob body.

The embodiment of the invention also provides the circular tube type anastomat which comprises the knob assembly.

The knob assembly and the circular tube type anastomat provided by the invention have the following advantages:

the invention provides a knob assembly for a circular tube type anastomat, which is divided into a knob body and a knob driving piece, wherein the knob driving piece is selectively linked with the knob body, the knob driving piece can drive the knob body to rotate together before the rotation resistance borne by the knob body reaches a preset resistance value, the knob body can drive a nail anvil assembly to move along the axial direction of the anastomat through a lead screw to be close to a nail bin, after the rotation resistance borne by the knob body reaches the preset resistance value, the knob driving piece cannot drive the knob body to rotate due to the deformation of an elastic fitting piece, at the moment, the knob assembly enters a failure mode, the gap between the nail anvil assembly and the nail bin is kept unchanged, and tissues cannot be excessively squeezed.

Drawings

Other features, objects and advantages of the present invention will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a stapler according to a first embodiment of the invention;

FIG. 2 is a schematic view of the knob assembly of the first embodiment of the present invention engaged with a lead screw;

FIG. 3 is a sectional view taken in the direction A1-A1 of FIG. 2;

FIG. 4 is a schematic view of the structure of a second boss according to the first embodiment of the present invention;

FIG. 5 is a schematic structural view of a knob body according to a first embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a spring plate according to the first embodiment of the present invention;

FIG. 7 is a schematic structural view of a knob housing according to a first embodiment of the present invention;

FIG. 8 is a schematic structural view of a first rotary knob rear cover according to the first embodiment of the present invention;

FIG. 9 is a schematic view of a knob assembly of the second embodiment of the present invention engaged with a lead screw;

FIG. 10 is a sectional view taken in the direction A2-A2 of FIG. 9;

FIG. 11 is a schematic structural view of a knob body according to a second embodiment of the present invention;

fig. 12 is a schematic structural view of a spring plate according to a second embodiment of the present invention;

fig. 13 is a schematic structural view of a knob housing according to a second embodiment of the present invention.

Reference numerals:

first embodiment

1 second end of 213 spring plate of knob body

11 first guiding surface of the convex 214 elastic sheet

111 second guide surface of the first side 215 of the projection

112 raised second side 22 spring plate mounting groove

12 body external thread 5 first knob rear cover

13 body internal thread 51 rear cover internal thread

14 first boss 6 screw rod

15 second boss 7 second knob rear cover

2 knob shell 81 anastomat body shell

21 elastic sheet 82 nail bin assembly

211 spring lug 83 anvil assembly

212 spring plate first end 84 handle

Second embodiment

3 32 shell fragment mounting grooves of knob body

31 spring piece 33 first boss

311 projection 34 of shrapnel and second boss

312 first end 4 knob shell of shell fragment

313 the second end 41 of the elastic sheet is convex

First side surface of the first guide surface 411 of the 314 elastic sheet

315 second side surface of the spring plate protruding from the second guide surface 412

Detailed Description

Example embodiments will now be described in more detail with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their repetitive description will be omitted.

In order to solve the technical problems in the prior art, the invention provides a knob assembly for a circular tube type anastomat, wherein a screw rod is arranged inside the anastomat, the knob assembly comprises a knob driving piece and a knob body which are selectively linked, the knob body is sleeved outside the screw rod, and the screw rod is driven to move along the axial direction of the anastomat when the knob body rotates. One of two fitting pieces is arranged on the knob driving piece and the knob body respectively, and the two fitting pieces comprise a first fitting piece and a second fitting piece. That is, the first mating member and the second mating member are respectively disposed on the knob driving member and the knob body, or the first mating member and the second mating member are respectively disposed on the knob body and the knob driving member. The invention further provides a circular tube type anastomat which comprises the knob assembly.

The first fitting piece is an elastic fitting piece, the first fitting piece is provided with a blocking state and a yielding state, the first fitting piece is in the blocking state and linked with the second fitting piece, and the first fitting piece is in the yielding state and not linked with the second fitting piece.

When an operator rotates the knob driving piece along the first direction, the knob driving piece transmits rotating torque through the two matching pieces, before the rotating resistance borne by the knob body reaches a resistance preset value, the first matching piece is in a blocking state, namely, the relative motion between the knob driving piece and the knob body is blocked, the knob driving piece can drive the knob body to rotate together through the two matching pieces, namely, the two matching parts are in a linkage state, and the knob body further drives the nail anvil assembly to move along the axial direction of the anastomat through the lead screw to be close to the nail anvil assembly.

Along with the nail anvil subassembly is close to the nail storehouse subassembly gradually, when reaching suitable distance between nail anvil subassembly and the nail storehouse subassembly, when reaching suitable predetermined value to the squeezing force of tissue simultaneously, rotatory knob again, this can receive the rotatory resistance that hinders first direction of knob body, and this resistance is corresponding to the tissue squeezing force between nail anvil subassembly and the nail storehouse subassembly promptly, and at this moment, only exert the rotation torque who is greater than this resistance on the knob body and just can follow first direction and rotate the knob body. Namely, after the rotational resistance that the knob body receives reached the resistance default, the interact power between first fitting piece and the second fitting piece is greater than the power of overcoming elastic deformation of elastic fitting piece, and first fitting piece produces and warp and gets into the state of stepping down, no longer blocks the relative motion between knob driving piece and the knob body promptly, and knob driving piece and knob body no longer link, and the knob subassembly at this moment gets into failure mode, and the clearance between nail anvil subassembly and the nail storehouse remains unchanged, and can not make the tissue excessively squeezed.

The circular tube type anastomat and the knob assembly thereof provided by the two embodiments of the invention are described in detail in the following with reference to the accompanying drawings. Fig. 1 to 8 show a structure of a knob assembly according to a first embodiment of the present invention, in which a first mating member is disposed on a knob driving member, and a second mating member is disposed on a knob body; fig. 9 to 13 show the structure of a knob assembly according to a second embodiment of the present invention, in which a first engaging member is provided on a knob body and a second engaging member is provided on a knob driver.

As shown in fig. 1, the structure of the stapler of the first embodiment is shown. The anastomat comprises an anastomat body and a nail anvil assembly 83, wherein the anastomat body comprises an anastomat shell 81, a nail bin assembly 82 located at the far end of the anastomat shell 81, a knob assembly located at the near end of the anastomat shell 81 and a screw rod 6 arranged from the near end to the far end, the nail bin assembly 82 comprises an annular nail bin and a cutter, the nail anvil assembly 83 comprises a nail anvil and a nail anvil shaft, and the nail anvil is connected to the far end of the screw rod through the nail anvil shaft. When the knob assembly rotates, the anvil assembly 83 is driven to move axially through the screw rod and the anvil shaft in sequence and is far away from or close to the nail bin assembly 82.

Of course, in another type of circular tube-type anastomat, such as the aforementioned circular tube-type anastomat for performing hemorrhoid surgery, the anvil assembly 83 is directly connected to the anastomat body, and the anvil assembly 83 cannot be removed from the anastomat body, and at this time, the anvil assembly 83 does not include an anvil shaft, and the anvil is directly connected to the distal end of the screw rod.

As shown in FIGS. 2 to 8, the knob assembly includes a knob body 1 and a knob driver. In this embodiment, the knob driver is a knob housing 2, and the operator directly contacts the knob housing 2 when operating the knob assembly, but the present invention is not limited thereto. The knob body 1 is sleeved outside the screw rod 6, and the knob body 1 is matched with the screw rod 6 through an internal body internal thread 13. When the knob body 1 rotates along the first direction, the screw rod 6 can be driven to move towards the proximal end of the anastomat, and the nail anvil assembly 83 is further driven to approach the nail bin assembly 82. When the knob body 1 rotates along the second direction, the screw rod 6 can be driven to move towards the distal end of the stapler, so that the nail anvil assembly 83 is far away from the nail bin assembly 82. In this embodiment, the first mating member is disposed on the knob housing 2, and the second mating member is disposed on the knob body 1. Wherein, first fitting piece is resilient fitting spare, just first fitting piece has the state of blockking and the state of stepping down, when first fitting piece is in the state of blockking, first fitting piece and the linkage of second fitting piece, knob shell 2 and knob body 1 link, when first fitting piece is in the state of stepping down, first fitting piece and second fitting piece do not link, and knob shell 2 and knob body 1 do not link.

In this embodiment, the first mating member is a spring 21 having a protrusion 211. An elastic piece mounting groove 22 is formed on an inner side surface of the knob housing 2, and a first end 212 and a second end 213 of the elastic piece 21 are mounted in the elastic piece mounting groove 22. The elastic sheet 21 may be a metal elastic sheet or a plastic elastic sheet, or other structures that can elastically deform and recover to an initial state after an external force is removed. The elastic engagement element is only one arrangement, and in other alternative embodiments, the elastic engagement element may also adopt a structure that a spring is engaged with a movable block, and the like, and all of them fall within the protection scope of the present invention.

The second mating member comprises at least one mating structure, and the mating structure is a protrusion or a groove. In this embodiment, the second mating member comprises a plurality of protrusions 11, and the plurality of protrusions 11 are uniformly distributed on the outer side surface of the knob body 1. The protrusion 11 has a first side 111 and a second side 112, and when the knob housing 2 rotates towards the first direction, the first side 111 of the protrusion 11 contacts the spring plate 21, and when the knob housing 2 rotates towards the second direction, the second side 112 of the protrusion 11 contacts the spring plate 21.

When the operator operates the knob subassembly, at first, exert external force and make knob shell 2 receive external force and rotate, knob shell 2 transmits external force to knob body 1 through two mating members with knob body 1, first mating member can give a rotational force of second mating member, if the rotational resistance of knob body 1 is less than preset resistance value this moment, the reaction force that the second mating member was given first mating member is less than the power of overcoming elastic deformation of shell fragment 21, shell fragment 21 can not take place to warp, first mating member is in and blocks the state, knob shell 2 drives knob body 1 through shell fragment 21 and bellied 11's cooperation and rotates together. When the operator applys external force drive knob shell 2 and rotates, if the rotational resistance of knob body 1 reaches or is greater than and predetermines the resistance value, the operator need apply bigger external force, protruding 11 is greater than 2 overcoming elastic deformation's of shell fragment power for the reaction force of shell fragment 21 this moment, shell fragment 21 receives the effort of protruding 11 to produce and warp and get into the state of stepping down, protruding 11 and shell fragment 21 can't transmit external force to knob body 1 promptly on, knob shell 2 can't link with knob body 1, what knob shell 2 went on is invalid idle running, and can send the sound of clicking when protruding 11 and shell fragment 21 are tripped. At this time, the knob assembly is in a failure state, the staple forming gap between the anvil assembly 83 and the cartridge assembly 82 is kept unchanged, and the tissue is not excessively squeezed. If the operator hears a click or, based on the feel of the rotary knob assembly at the time of the failure condition, can determine that the current anvil assembly 83 has moved into position, the stapling operation can be performed.

In this embodiment, the resilient plate 21 includes a first guide surface 214, and when the knob housing 2 is rotated in the first direction, the first guide surface 214 of the resilient plate 21 contacts the protrusion 11. The first guide surface 214 may be a curved surface or a sloped surface. The resilient plate 21 may further include a second guiding surface 215, when the knob housing 2 is rotated toward the second direction, the second guiding surface 215 of the resilient plate 21 contacts the protrusion 11, and the second guiding surface 215 may be an arc surface or an inclined surface.

As shown in fig. 2, a first boss 14 is disposed on an outer side surface of the knob body 1, a second boss 15 is further disposed on a proximal end side of the first boss 14, and the protrusion 11 is disposed on the second boss 15. And as shown in fig. 3 and 4, the second boss 15 and the plurality of protrusions 11 form a gear disk structure. Here, it is only an embodiment, and in other alternative embodiments, only one boss may be provided, or the second boss 15 may be provided on the distal end side of the first boss 14, etc., all falling within the protection scope of the present invention.

In this embodiment, the height of the projection 11 on the second boss 15 is lower than the height of the first boss 14; suitably, the distal end of the rotary shell 2 is provided with a stepped surface cooperating with the first boss 14 to limit the movement of the knob housing in the axial direction; the inner side of the far end of the rotary shell 2 is provided with an elastic sheet 2 matched with the bulge 11.

Further, the near-end of knob subassembly still is provided with lid behind the knob, lid 7 behind the knob includes lid 5 behind first knob and the second knob, and the distal end of lid 5 behind the first knob is provided with back lid internal thread 51, the near-end of knob body 1 be provided with lid internal thread matched with body external screw thread 12 behind, lid 5 passes through threaded connection in the near-end cooperation of knob body 1 behind the first knob, lid 7 can install in the near-end of lid 5 behind the first knob behind the second knob.

In the viewing angles in fig. 3 and 4, the first direction is clockwise and the second direction is counter-clockwise. As shown in fig. 3 and 4, in this embodiment, the first side 111 of the protrusion 11 is inclined toward the first direction, so that the deformed striking flake 2 can more easily pass over the protrusion 11 when the knob housing 2 is rotated in the clockwise direction and is not interlocked with the knob body 1. The second side 112 of the protrusion 11 is a substantially right angle surface or the second side 112 is inclined toward the second direction to prevent the knob housing from rotating in the second direction to give the surgeon tactile feedback indicating the direction of rotation. The second side surface 112 of the protrusion 11 is an approximate right-angled surface, which means that the second side surface 112 is substantially perpendicular to the outer side surface of the knob body 1. If the second side 112 of the protrusion 11 is inclined toward the second direction, the second side 112 is inclined to a lesser extent than the first side 111. Due to the arrangement, when the knob shell 2 rotates along the second direction, the elastic sheet 2 is not easy to cross the protrusion 11, so that the knob assembly is prevented from being screwed along the first direction, and when reverse operation is needed, the knob body 1 cannot be driven to rotate along the second direction to increase the distance between the nail bin assembly 82 and the nail anvil assembly 83.

As shown in FIGS. 9 to 13, the structure of a knob assembly according to a second embodiment of the present invention is shown. The second embodiment differs from the first embodiment in that: the first mating member is disposed on the knob body 3, and the second mating member is disposed on the knob housing 4.

In the perspective of fig. 10, the first direction is counterclockwise and the second direction is clockwise. The first mating member is a spring plate 31 including a protrusion 311, and the second mating member includes a plurality of protrusions 41 disposed on an inner side surface of the knob housing 4. When the knob body 3 rotates along the first direction, the elastic sheet 31 contacts with the first side surface 411 of the protrusion 41, and when the knob body 3 rotates along the second direction, the elastic sheet 31 contacts with the second side surface 412 of the protrusion 41. Similarly, the inclination degree of the first side 411 is greater than the inclination degree of the second side 412, so that when the rotary housing 4 rotates along the first direction and the rotation resistance of the knob body 3 is greater than the preset resistance value, the elastic sheet 31 is more easily disengaged from the protrusion 41, and it is ensured that after the rotary housing 4 is screwed along the first direction, the knob body 3 can be driven to rotate along the second direction through the knob housing 4.

The outer side surface of the knob body 3 is provided with an elastic piece mounting groove 32, and two

ends

312 and 313 of the elastic piece 31 are respectively arranged in the elastic piece mounting groove 32. The spring plate 31 includes a first guide surface 314 and a second guide surface 315. When the knob body 3 is rotated in the first direction, the first guide surface 314 of the resilient piece 31 contacts the first side surface 411 of the protrusion 41, and when the knob body 3 is rotated in the second direction, the second guide surface 315 of the resilient piece 31 contacts the second side surface 412 of the protrusion 41.

In this embodiment, the knob body 1 is provided with a first boss 33 and a second boss 34, and the second boss 34 is provided on the proximal end side of the first boss 33. The first boss 33 interacts with the distal end of the knob housing 4 to limit axial movement of the knob housing. The spring plate mounting groove 32 is disposed on the outer surface of the second boss 34. The distal end of the knob housing 4 mates with the first boss 33.

The operation principle of the knob assembly according to the second embodiment is similar to that of the knob assembly according to the first embodiment. When the operator operates the knob subassembly, at first, apply external force and make knob shell 4 rotatory, knob shell 4 transmits external force to knob body 3 through two mating members, first mating member can give the rotational force of second mating member, if the rotational resistance of knob body 3 is less than preset resistance value this moment, the effort that the second mating member was given first mating member is less than the power of overcoming elastic deformation of shell fragment 31, shell fragment 31 can not take place to warp, first mating member is in and blocks the state, knob shell 4 drives knob body 3 through the cooperation of shell fragment 31 and arch 41 and rotates together. When the external force is applied to the operator to drive the knob shell 4 to rotate, if the rotation resistance of the knob body 3 reaches or is greater than a preset resistance value, the operator needs to apply larger external force, the acting force of the protrusion 41 on the elastic sheet 31 is greater than the force of the elastic sheet 31 on overcoming elastic deformation, the elastic sheet 31 deforms under the action of the protrusion 41 and enters a abdicating state, namely, the protrusion 41 and the elastic sheet 31 cannot transmit the external force to the knob body 3, the knob shell 4 cannot be linked with the knob body 3, the knob shell 4 does not idle, and the clicking sound generated when the protrusion 41 and the elastic sheet 31 are tripped can be emitted. At this time, the knob assembly is in a failure state, the staple forming gap between the anvil assembly 83 and the cartridge assembly 82 is kept unchanged, and the tissue is not excessively squeezed. If the operator hears a click or, based on the feel of the rotary knob assembly at the time of the failure condition, can determine that the current anvil assembly 83 has moved into position, the stapling operation can be performed.

It is understood that, in the first embodiment and the second embodiment, the number of the elastic pieces may be two or more, for example, when there are two elastic pieces, the two elastic pieces may be symmetrically arranged to enhance the structural stability.

The two embodiments given in the present invention are only examples, and in practical applications, some features in the two embodiments may also be combined to obtain a new technical solution. Or some of the features may be changed to obtain a new technical solution, all of which are within the protection scope of the present invention. For example, the first fitting piece may not adopt a structure of a spring piece, but adopt a structure of a movable block and a spring, the magnitude of the force overcoming the elastic deformation is the spring force of the spring, the second fitting piece may also adopt a structure of a groove instead of a protrusion, and the number and arrangement mode of the fitting structures may also be selected as required.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims

1. A knob assembly is characterized by being used for a circular tube type anastomat, wherein a screw rod is arranged inside the anastomat; the knob assembly includes:

2. The knob assembly according to claim 1, wherein the knob driving member is rotated by an external force, and when the rotational resistance of the knob body is greater than a predetermined resistance value, the first engaging member is deformed by the action force of the second engaging member to enter the abdicating state.

3. The knob assembly according to claim 2, wherein the first engagement member is a spring plate having a protrusion.

4. The knob assembly according to claim 3, wherein the knob driving member or the knob body is provided with a spring plate mounting groove, and both ends of the spring plate are mounted in the spring plate mounting groove.

5. The knob assembly according to claim 3, wherein the resilient tab includes a first guide surface, the first guide surface of the first mating member contacting the second mating member when the knob driver is rotated in the first direction.

6. The knob assembly according to claim 5, wherein the first guide surface is a curved surface or a sloped surface.

7. The knob assembly according to claim 5, wherein the resilient tab includes a second guide surface, the second guide surface of the first mating member contacting the second mating member when the knob driver is rotated in the second direction.

8. The knob assembly according to claim 7, wherein the second guide surface is a curved surface or a sloped surface.

9. The knob assembly according to claim 1, wherein the second engagement member comprises at least one engagement feature, the engagement feature being a protrusion or a recess.

10. The knob assembly according to claim 9, wherein the engagement structure includes a first side surface, the first side surface of the engagement structure contacting the first engagement member when the knob driver is rotated in a first direction, the first side surface being inclined in the first direction.

11. The knob assembly according to claim 10, wherein the engagement structure includes a second side surface, the second side surface of the engagement structure contacting the first engagement member when the knob driver is rotated in the second direction.

12. The knob assembly according to claim 11, wherein the second side of the mating structure is a right angled surface or the second side of the mating structure is inclined toward the second direction, and the second side of the mating structure is inclined less than the first side of the mating structure.

13. The knob assembly according to claim 1, wherein the knob driver comprises a knob housing, an inner side surface of the knob driver being provided with the first or second mating member.

14. The knob assembly according to claim 13, wherein an outer side of the knob body is provided with a first boss, the first engagement member is provided to an inner side of the knob housing, and the second engagement member is provided to a proximal or distal side of the boss; or

15. The knob assembly according to claim 14, wherein the outer side of the knob body is further provided with a second boss located at a proximal side of the first boss;

16. The knob assembly according to claim 1, further comprising a knob back cover at a proximal end of the knob body, wherein a distal end of the knob back cover is provided with back cover internal threads, and a proximal end of the knob body is provided with body external threads that mate with the back cover internal threads.

17. A circular tube-type anastomat, comprising the knob assembly of any one of claims 1 to 16.