Knob assembly and circular tube type stapler

Abstract

The present invention provides a knob assembly and a circular tube type stapler. The knob assembly includes a knob body, a clutch member, and a knob rear cover. A first mating portion is provided on the knob body. When the knob body rotates, it drives a lead screw to move axially along the stapler. A second mating portion is provided on the clutch member, and a compression spring is provided between the knob rear cover and the clutch member. In the present invention, the knob assembly is divided into a knob body and a clutch member. Before the resistance received by the knob body reaches a preset value, rotating the clutch member can drive the knob body to rotate together. The knob body can drive the anvil assembly to move axially along the stapler to approach the cartridge. After the resistance received by the knob reaches the preset value, the clutch member cannot drive the knob body to rotate. At this time, the knob assembly enters a failure mode, and the gap between the anvil assembly and the cartridge remains unchanged, without over-pressing the tissue.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a knob assembly and a circular tubular stapler. Background Art

[0002] Digestive tract diseases are one of the most common diseases in humans. During the treatment process, circular tubular staplers are often used to replace the doctor's manual operation to anastomose physiological tissues such as the digestive tract. Circular tubular staplers are a common surgical instrument, most of which use axial internal stapling to form end-to-end or end-to-side anastomosis of physiological tissues such as the esophagus, stomach, and intestines during surgery. During the anastomosis, the two sections of tissue are contained inwardly in the stapler. After the firing is completed, a circular anastomosis is formed on the tissue, reconstructing the human body channel.

[0003] In the prior art, a circular tube-type stapler includes a stapler body, an operating handle movably connected to the stapler body, and a nail anvil assembly matched with the body. The stapler body includes a nail magazine assembly arranged at the distal end, the nail magazine assembly includes an annular nail magazine, a cutter; and a knob arranged at the proximal end of the body, the knob can rotate relative to the body, and the interior of the stapler body also includes a nail anvil shaft arranged from the proximal end to the distal end. Here, the distal end and the proximal end are relative to the operator, the end closer to the operator is the proximal end, and the end farther from the operator, that is, the end closer to the surgical site is the distal end. In the stapler, the inner side and the outer side are relative to the axis of the stapler, the side close to the axis is the inner side, and the side away from the axis is the outer side. The nail anvil assembly includes a nail anvil, a nail anvil cap arranged at the distal end of the nail anvil, and a knife anvil arranged inside the nail anvil. The nail anvil assembly can be directly connected to the distal end of the nail anvil shaft or connected through a nail anvil shaft connector. During tumor surgery, after the tumor tissue is cut off and removed, the anvil shaft passes through the purse of the residual tissue and is arranged at the distal end of the stapler body. The knob is rotated to gradually reduce the distance between the anvil assembly and the stapler to a suitable distance, and then the firing state is reached. Only then can the operating handle be held to fire the instrument to complete the anastomosis. With the continuous development of medical devices, circular tube staplers are also increasingly widely used in the treatment of hemorrhoids and other diseases.

[0004] In the process of rotating the knob to move the anvil assembly closer to the nail magazine, sometimes the knob can still be rotated after the tissue is closed. In this way, the anvil assembly and the nail magazine will continue to get closer, continue to compress the tissue, cause excessive squeezing of the tissue, and may even crush the tissue, which is very unfavorable to the surgical outcome. Summary of the invention

[0005] In view of the problems in the prior art, the purpose of the present invention is to provide a knob assembly and a circular tube type stapler. When rotating the knob, when the resistance received by the knob reaches the preset resistance value, the knob will no longer be able to transmit a greater torque. At this time, the knob enters the failure mode, and the gap between the anvil assembly and the cartridge remains unchanged, without over-pressing the tissue.

[0006] An embodiment of the present invention provides a knob assembly for a circular tube type stapler. A lead screw is provided inside the stapler. The knob assembly includes:

[0007] A knob body sleeved outside the lead screw. A driving member is provided on the knob body. A first fitting portion is provided on the proximal end face of the driving member. When the knob body rotates, it drives the lead screw to move along the axial direction of the stapler.

[0008] A clutch member located at the proximal end of the driving member. A second fitting portion is provided on the distal end face of the clutch member. The second fitting portion can axially move relative to the first fitting portion. When the second fitting portion is in contact and cooperation with the first fitting portion, the rotation of the clutch member drives the rotation of the knob body.

[0009] A knob rear cover located at the proximal end of the knob body, and a compression spring is provided between the knob rear cover and the proximal end face of the clutch member.

[0010] Optionally, the first fitting portion includes at least one first fitting member provided on the proximal end face of the driving member, and the second fitting portion includes second fitting members corresponding to the first fitting members one by one.

[0011] Optionally, the first fitting member is a first protrusion, and the second fitting member is a second protrusion.

[0012] Optionally, the first fitting member is a first protrusion, and the second fitting member is a groove.

[0013] Optionally, the first fitting member is a groove, and the second fitting member is a protrusion.

[0014] Optionally, the first fitting member includes a first side face, and the second fitting member includes a third side face. When the clutch member rotates under an external force in the first direction, the first side face of the first fitting member is in contact and cooperation with the third side face of the second fitting member, and the first side face of the first fitting member is inclined towards the first direction.

[0015] Optionally, the first fitting member further includes a second side face, and the second fitting member further includes a fourth side face. When the clutch member rotates under an external force in the second direction, the second side face of the first fitting member is in contact and cooperation with the fourth side face of the second driving member.

[0016] Optionally, the second side surface of the first fitting member is a right-angle surface, or the second side surface of the first fitting member inclines towards the second direction and the inclination degree of the second side surface of the first fitting member is less than that of the first side surface.

[0017] Optionally, both the first side surface of the first fitting member and the third side surface of the second fitting member are flat surfaces or mating curved surfaces, and both the second side surface of the first fitting member and the fourth side surface of the second fitting member are flat surfaces or mating curved surfaces.

[0018] Optionally, the clutch member includes a clutch ring sleeved outside the knob body.

[0019] Optionally, the stapler further includes a knob housing, and a fourth fitting portion is provided on the inner surface of the knob housing;

[0020] The clutch member is located inside the knob housing, and a third fitting portion is provided on the side surface of the clutch member. The third fitting portion mates with the fourth fitting portion so that the knob housing can drive the clutch member to rotate, and the clutch member can axially move relative to the knob housing.

[0021] Optionally, the third fitting portion includes at least one orientation groove located on the side surface of the clutch member, the fourth fitting portion includes orientation ribs corresponding to the orientation grooves one by one, the orientation ribs extend along the axial direction of the stapler and extend into the orientation grooves, and the orientation grooves can move along the extending direction of the orientation ribs.

[0022] Optionally, the third fitting portion includes at least one orientation rib located on the side surface of the clutch member, the fourth fitting portion includes orientation grooves corresponding to the orientation ribs one by one, the orientation ribs extend along the axial direction of the stapler and extend into the orientation grooves, and the orientation ribs can move along their own extending directions.

[0023] Optionally, a step portion is provided on the inner surface of the knob housing, and the step portion is located at the distal end surface of the clutch member.

[0024] Optionally, an internal thread of the rear cover is provided at the distal end of the knob rear cover, and an external thread of the body that mates with the internal thread of the rear cover is provided at the proximal end of the knob body.

[0025] An embodiment of the present invention further provides a circular tube type stapler including the above-mentioned knob assembly.

[0026] The knob assembly and the circular tube type stapler provided by the present invention have the following advantages:

[0027] The present invention provides a knob assembly for a circular tube stapler. The knob assembly is divided into a knob body and a clutch member. Before the resistance received by the knob body reaches the preset resistance value, rotating the clutch member can drive the knob body to rotate together. The knob body can drive the anvil assembly to move axially along the stapler to approach the cartridge. After the resistance received by the knob reaches the preset resistance value, the clutch member cannot drive the knob body to rotate. At this time, the knob assembly enters a failure mode, and the gap between the anvil assembly and the cartridge remains unchanged, without over-compressing the tissue. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Other features, objects, and advantages of the present invention will become more apparent by reading the detailed description of the non-limiting embodiments with reference to the following drawings.

[0029] Figure 1 is a schematic structural diagram of a stapler according to an embodiment of the present invention;

[0030] Figure 2 is a schematic diagram of the cooperation between the knob assembly and the lead screw according to an embodiment of the present invention;

[0031] Figure 3 is a schematic structural diagram of the knob body according to an embodiment of the present invention;

[0032] Figure 4 is a schematic structural diagram of the clutch ring according to an embodiment of the present invention;

[0033] Figure 5 is a schematic structural diagram of the knob housing according to an embodiment of the present invention;

[0034] Figure 6 is a schematic structural diagram of the first knob rear cover according to an embodiment of the present invention;

[0035] Figure 7 is a schematic diagram of the cooperation between the knob body and the clutch ring in the initial state according to an embodiment of the present invention;

[0036] Figure 8 is a schematic diagram of the cooperation between the knob body and the clutch ring in the failure state of the knob assembly according to an embodiment of the present invention.

[0037] Reference Signs:

[0038] 1 Knob Body 3 Compression Spring

[0039] 11 First Projection 4 Knob Housing

[0040] 111 First Side 41 Orientation Rib

[0041] 112 Second Side 42 Step Portion

[0042] 12 Outer thread of the body 5 First knob rear cover

[0043] 13 Inner thread of the body 51 Inner thread of the rear cover

[0044] 14 Driving member 6 Lead screw

[0045] 2 Clutch ring 7 Second knob rear cover

[0046] 21 Second protrusion 81 Stapler body housing

[0047] 211 Third side 82 Cartridge assembly

[0048] 212 Fourth side 83 Anvil assembly

[0049] 22 Orientation groove 84 Handle

[0050] 23 Distal end face of the clutch ring Detailed implementation manners

[0051] Example embodiments will now be described more specifically with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote the same or similar structures, and thus their repeated description will be omitted.

[0052] To solve the technical problems in the prior art, the present invention provides a knob assembly, which includes a knob body, a clutch member and a knob rear cover. The knob body is sleeved outside the lead screw, and a driving member is arranged on the knob body. A first engaging portion is arranged on the proximal end face of the driving member. When the knob body rotates, it drives the lead screw to move axially along the stapler. The clutch member is located at the proximal end of the driving member, and a second engaging portion is arranged on the distal end face of the clutch member. The second engaging portion can axially move relative to the first engaging portion. The second engaging portion has a first state in which it can drive the first engaging portion, and a second state in which it cannot drive the first engaging portion. When the second engaging portion is in the first state, the rotation of the clutch member drives the knob body to rotate. When the second engaging portion is in the second state, the rotation of the clutch member does not drive the knob body to rotate, and the clutch member axially moves proximally relative to the knob body. The knob rear cover is located at the proximal end of the knob body, and a compression spring is arranged between the knob rear cover and the proximal end face of the clutch member.

[0053] Therefore, in the present invention, the knob assembly is divided into a knob body and a clutch member. Additionally, a knob rear cover and a positioning compression spring are provided at the proximal end of the knob body. The axial movement of the clutch member towards the proximal end of the stapler is hindered by the compression spring, that is, the axial movement of the clutch member needs to overcome the spring force of the compression spring. The driving member of the knob body and the clutch member together form a clutch structure. When the operator rotates the knob assembly, the first component to be rotated by the rotational force of the operator is the clutch member. Before the resistance received by the knob body reaches the resistance preset value, the clutch mechanism can transmit a torque greater than the resistance of the knob body, and the knob body and the clutch member are linked. Rotating the clutch member can drive the knob body to rotate together, and the knob body can drive the anvil assembly to move axially along the stapler to approach or move away from the staple cartridge. When the resistance received by the knob reaches the resistance preset value, the clutch mechanism cannot transmit a torque greater than the resistance of the knob body. The clutch member moves towards the proximal end of the stapler and disengages from the driving member, and compresses the compression spring. At this time, the clutch member cannot drive the knob body to rotate, and the knob assembly enters a failure mode. The gap between the anvil assembly and the staple cartridge remains unchanged, and the tissue will not be over-pressed. Among them, the magnitude of the resistance preset value is determined by the inclination angle of the contact surface between the driving member and the clutch member and the spring force of the compression spring. The magnitude of the resistance preset value corresponds to the magnitude of the maximum tissue pressing force for pressing the tissue between the anvil assembly and the staple cartridge assembly.

[0054] An embodiment of the present invention further provides a circular tube type stapler. The knob assembly is located at the proximal end of the stapler. A staple cartridge assembly and an anvil assembly are provided at the distal end of the stapler. The anvil assembly is connected to the distal end of the lead screw through an anvil shaft or directly connected to the distal end of the lead screw. When the knob body rotates, the anvil assembly can be driven by the anvil shaft to move axially along the stapler to approach or move away from the staple cartridge assembly.

[0055] In the initial state when the anvil assembly and the stapler body having the staple cartridge assembly are just successfully docked, rotating the knob in the first direction, the clutch member rotates. At this time, since the tissue has not been clamped yet, the resistance received by the knob body has not reached the resistance preset value. The clutch mechanism can transmit a torque greater than the resistance of the knob body. The compression spring remains in the initial state, without deformation or with a certain amount of initial deformation. The clutch member drives the knob body to rotate in the first direction, that is, the second mating portion is in the first state and drives the first mating portion, and the anvil assembly is driven by the anvil shaft and the lead screw to gradually approach the staple cartridge assembly.

[0056] After the tissue is clamped between the anvil assembly and the cartridge assembly, rotate the knob. The knob body will be subject to a resistance that hinders rotation in the first direction. This resistance corresponds to the tissue pressing force between the anvil assembly and the cartridge assembly. At this time, only by applying a rotational torque greater than this resistance on the knob body can the knob body be rotated in the first direction. When this resistance is greater than the preset resistance value, if a greater rotational torque is applied to rotate the clutch member, the reaction force of the rotational torque received by the knob body is applied to the clutch member. This reaction force will overcome the spring force of the compression spring and compress the compression spring to cause deformation. The clutch member will generate an axial movement towards the proximal end of the stapler, causing the second mating portion of the clutch member to disengage from the first mating portion of the knob body, that is, the second mating portion is in the second state and does not drive the first mating portion. At this time, the clutch member cannot transmit the rotational torque applied by the operator to the knob body, and the knob body will not rotate. The clutch member performs an ineffective idling rotation and can emit a clicking sound when the first mating portion and the second mating portion are disengaged. At this time, the knob assembly is in a failure state, and the staple forming gap between the anvil assembly and the cartridge assembly remains unchanged, and the tissue will not be over-pressed.

[0057] The following will introduce in detail the circular tube type stapler and the knob assembly therein provided by an embodiment of the present invention with reference to the accompanying drawings.

[0058] As Figure 1 shown, the structure of a stapler according to an embodiment is shown. Among them, the stapler includes a stapler body and an anvil assembly 83. Among them, the stapler body includes a stapler housing 81, a cartridge assembly 82 located at the distal end of the stapler housing 81, a knob assembly located at the proximal end of the stapler housing 81, and a lead screw 6 arranged from the proximal end to the distal end. The cartridge assembly 82 includes an annular cartridge and a cutter. The anvil assembly 83 includes an anvil and an anvil shaft. The anvil is connected to the distal end of the lead screw through the anvil shaft. When the knob assembly rotates, it drives the anvil assembly 83 to move axially away from or close to the cartridge assembly 82 in sequence through the lead screw and the anvil shaft.

[0059] Of course, in another type of circular tube type stapler, such as the circular tube type stapler for hemorrhoid surgery mentioned above, the anvil assembly 83 is directly connected to the stapler body, and the anvil assembly 83 cannot be removed from the stapler body. At this time, the anvil assembly 83 does not include an anvil shaft, and the anvil is directly fixedly connected to the distal end of the lead screw 6. The present invention will be described by taking this type of stapler as an example.

[0060] As Figures 2 to 6As shown, the knob assembly includes a knob body 1, a clutch member, and a knob rear cover. The knob body 1 is sleeved outside the lead screw 6. A driving member 14 is provided on the knob body 1. A first mating portion is provided on the proximal end face of the driving member 14. An internal thread 13 of the body is provided inside the knob body 1. The internal thread 13 of the body mates with the lead screw 6 of the stapler. When the knob body 1 rotates, it drives the lead screw 6 to move axially along the stapler. The clutch member is located at the proximal end of the driving member 14. A second mating portion is provided on the distal end face of the clutch member. The second mating portion can axially move relative to the first mating portion. The second mating portion has a first state in which it can drive the first mating portion and a second state in which it cannot drive the first mating portion. When the second mating portion is in the first state, the rotation of the clutch member drives the knob body 1 to rotate. When the second mating portion is in the second state, the rotation of the clutch member does not drive the knob body to rotate, and the clutch member axially moves proximally relative to the knob body. The knob rear cover is located at the proximal end of the knob body 1, and a compression spring 3 is provided between the knob rear cover and the proximal end face of the clutch member.

[0061] In this embodiment, the clutch member includes a clutch ring 2. The clutch ring 2 is sleeved on the knob body 1. The first mating portion includes at least one first mating member provided on the proximal end face of the driving member 14. The second mating portion includes second mating members corresponding one by one to the first mating members. The first mating member can be a first protrusion 11, and the second mating member can be a second protrusion 21. In other alternative embodiments, the first mating member and the second mating member can also be selected as other structures. For example, the first mating member is a protrusion and the second mating member is a groove that mates with the protrusion, or the first mating member is a groove and the second mating member is a protrusion that mates with the groove, etc., all of which fall within the protection scope of the present invention. Further preferably, the first protrusion 11 includes a first side face 111, and the second protrusion 21 includes a third side face 211. When the clutch ring 2 is rotated along the first direction by an external force, the first side face 111 of the first protrusion 11 contacts and mates with the third side face 211 of the second protrusion 21, and the first side face 111 of the first protrusion 11 is inclined toward the first direction. The inclination direction of the third side face 211 of the second protrusion 11 is adapted to the first side face 111.

[0062] In the perspective of the stapler from the proximal end toward the distal end, the first direction is the clockwise direction, and the second direction is the counterclockwise direction. When the clutch ring 2 is rotated clockwise and drives the knob body 1 to rotate clockwise, the lead screw 6 moves proximally along the stapler and drives the anvil assembly 83 closer to the cartridge assembly 82. When the clutch ring 2 is rotated counterclockwise and drives the knob body 1 to rotate counterclockwise, the lead screw 6 moves distally along the stapler and drives the anvil assembly 83 away from the cartridge assembly 82.

[0063] In this embodiment, the first side surface 111 and the third side surface 211 are in inclined surface fit. Through the inclined surface fit, when the resistance received by the knob body 1 is greater than the preset resistance value, when the clutch ring 2 is rotated in the first direction by an external force and applies a relatively large rotational torque to the knob body 1, the reaction force of the knob body 1 on the clutch ring 2 is decomposed by the inclined surface. After decomposition, the force along the axial direction of the stapler pushes the clutch ring 2 towards the proximal end of the stapler, so as to overcome the elastic force of the compression spring 3 and cause the compression spring 3 to deform, thereby gradually separating the knob body 1 from the clutch ring 2. The preset resistance value can be determined by the spring force of the compression spring 3 and the inclination degree of the first side surface 111 and the third side surface 211. In addition, due to the setting of the inclination degree of the first side surface 111 of the first protrusion 11 and the third side surface 211 of the second protrusion 21, when the clutch ring 2 rotates clockwise and is not linked with the knob body 1, the second protrusion 21 with a displacement towards the proximal end is more likely to be separated from the first protrusion 11.

[0064] In this embodiment, the first protrusion 11 further includes a second side surface 112, and the second protrusion 21 further includes a fourth side surface 212. When the clutch ring 2 is rotated in the second direction by an external force, the second side surface 112 of the first protrusion 11 is in contact fit with the fourth side surface 212 of the second protrusion 21, so as to facilitate driving the knob body 1 to rotate in the second direction to increase the distance between the anvil 83 and the cartridge assembly 82 when the clutch ring 2 is rotated in the second direction.

[0065] In this embodiment, the second side surface 112 of the first protrusion 11 is a right-angle surface. Correspondingly, the fourth side surface 212 of the second protrusion 21 is also a right-angle surface. Here, the right-angle surface means that the second side surface 112 of the first protrusion 11 is perpendicular to the surface of the driving member 14. In other alternative embodiments, the second side surface 112 of the first protrusion 11 may also be inclined towards the second direction and the inclination degree of the second side surface 112 of the first protrusion 11 is less than the inclination degree of the first side surface 111 of the first protrusion 11. Correspondingly, the inclination direction and angle of the fourth side surface 212 of the second protrusion 21 are adapted to the second side surface 112. Such a setting can make it difficult for the second protrusion 21 to be separated from the first protrusion 11 when the clutch ring 2 rotates in the second direction, so as to prevent the knob assembly from being unable to drive the knob body 1 to rotate in the second direction to increase the distance between the anvil assembly 83 and the cartridge assembly 82 when reverse operation is required after the knob assembly is tightened in the first direction.

[0066] The first side surface 111 of the first protrusion 11 and the third side surface 211 of the second protrusion 21 are both flat surfaces or mating curved surfaces, and the second side surface 112 of the first protrusion 11 and the fourth side surface 212 of the second protrusion 21 are both flat surfaces or mating curved surfaces.

[0067] In this embodiment, the knob rear cover includes a first knob rear cover 5 and a second knob rear cover 7. The distal end of the first knob rear cover 5 is provided with an internal thread 51 of the rear cover, and the proximal end of the knob body 1 is provided with an external thread 12 of the body that cooperates with the internal thread 51 of the rear cover. The first knob rear cover 5 is fitted to the proximal end of the knob body 1 by means of a thread, and the second knob rear cover 7 can be mounted on the proximal end of the first knob rear cover 5. The first knob rear cover 5 can provide support and limitation for the proximal end of the compression spring 3.

[0068] As Figure 7 and 8 shown, the structures of the cooperation between the knob body 1 and the clutch ring 2 in the initial state and the failure state are respectively shown.

[0069] In the initial state when the anvil assembly 83 and the stapler body are just successfully docked or in the initial state when the tissue is just incorporated, the knob assembly is in the initial state. The operator rotates the clutch ring 2 in the first direction. At this time, since the tissue has not been clamped, the resistance received by the knob body 1 has not reached the resistance preset value. The clutch mechanism can transmit the torque greater than the resistance of the knob body 1 from the clutch ring 2 to the knob body 1 through the cooperation between the first protrusion 11 and the second protrusion 21. At this time, the reaction force of the knob body 1 on the clutch ring 2 is not sufficient to overcome the elastic force of the compression spring 3. As Figure 7 shown, at this time, the compression spring 3 remains in the initial state, without deformation or with a certain amount of initial deformation. The second mating part is in the first state. The second protrusion 21 of the clutch ring 2 is in full contact and cooperation with the first protrusion 11 of the knob body 1. The rotation of the clutch ring 2 drives the knob body 1 to rotate in the first direction, and the anvil assembly 83 is driven by the lead screw 6 to gradually approach the cartridge assembly 82.

[0070] When the anvil assembly and the cartridge assembly reach an appropriate distance and the squeezing force on the tissue reaches an appropriate predetermined value, then rotate the clutch ring 2 of the knob assembly in the first direction. The knob body 1 will receive a resistance that hinders its rotation in the first direction. At this time, only by applying a rotational torque greater than this resistance on the knob body 1 can the knob body 1 be rotated in the first direction. That is, when this resistance is greater than the resistance preset value, if the operator applies a rotational torque less than this resistance to the clutch ring 2, the clutch ring 2 is hindered by the knob body 1 and cannot rotate. If the operator applies a rotational torque greater than this resistance to rotate the clutch ring 2, the reaction force of the rotational torque received by the knob body 1 is transmitted to the clutch ring 2 through the cooperation between the first protrusion 11 and the second protrusion 21. The component force of this reaction force in the axial direction will overcome the spring force of the compression spring 3 and compress the compression spring 3 to cause deformation. As Figure 8As shown, the clutch ring 2 will generate an axial movement towards the proximal end of the stapler, causing the second protrusion 21 of the clutch ring 2 to disengage from the first protrusion 11 of the knob body 1, that is, the second mating portion is in the second state. At this time, the clutch ring 2 cannot transmit the rotational torque applied by the operator to the knob body 1, the knob body 1 will not rotate, and the clutch ring 2 performs an ineffective idling rotation. Also, a clicking sound can be emitted when the first protrusion 11 and the second protrusion 21 disengage. At this time, the knob assembly is in a failure state, and the staple forming gap between the anvil assembly 83 and the cartridge assembly 82 remains unchanged, and the tissue will not be over-pressed. If the operator hears the clicking sound or can determine based on the feel of rotating the knob assembly in the failure state that the current anvil assembly 83 has moved into place, the stapler can perform the firing operation.

[0071] Furthermore, the stapler further includes a knob housing 4, and the inner surface of the knob housing 4 is provided with a fourth mating portion; the clutch ring 2 is located inside the knob housing 4, and a third mating portion is provided on the side surface of the clutch ring 2. The third mating portion cooperates with the fourth mating portion so that the knob housing 4 can drive the clutch ring 2 to rotate, and the clutch ring 2 can axially move relative to the knob housing 4.

[0072] When the operator rotates the knob assembly, it is the knob housing 4 linked to the clutch ring 2 that rotates, and the knob housing 4 does not restrict the axial movement of the clutch ring 2 towards the proximal end of the stapler and its return to the initial position. In this embodiment, the third mating portion includes at least one guiding groove 22 located on the axial side surface of the clutch ring 2, and the fourth mating portion includes guiding ribs 41 corresponding one-to-one to the guiding grooves 22. The guiding ribs 41 extend along the axial direction of the stapler and can extend into the guiding grooves 22, and the guiding grooves 22 can move along the extending direction of the guiding ribs 41, so as to realize that the clutch ring 2 can rotate together with the knob housing 4, and the clutch ring 2 can axially move relative to the knob housing 4. The guiding ribs 41 provide a guiding function for the guiding grooves 22. Preferably, there are two guiding grooves 22 and guiding ribs 41 respectively, and they are symmetrically arranged to achieve structural balance and force balance. Of course, there can also be multiple, or asymmetrically arranged.

[0073] In other embodiments, the third mating portion can also include at least one guiding rib located on the axial side surface of the clutch ring 2, and the fourth mating portion includes guiding grooves corresponding one-to-one to the guiding ribs. The guiding ribs extend along the axial direction of the stapler and extend into the guiding grooves, and the guiding ribs can move along their own extending direction, so as to realize that the clutch ring 2 can rotate together with the knob housing 4, and the clutch ring 2 can axially move relative to the knob housing 4.

[0074] Further, an L-shaped step portion 42 is provided on the inner surface of the knob housing 4, and the step portion 42 is located at the distal end surface of the clutch ring 2. The use of the step portion 42 can limit the movement of the clutch ring 2 in the direction towards the distal end of the stapler.

[0075] The circular stapler provided by the present invention has the following advantages:

[0076] The present invention provides a knob assembly for a circular stapler. The knob assembly is divided into a knob body and a clutch member. Before the resistance received by the knob body reaches the resistance preset value, rotating the clutch member can drive the knob body to rotate together. The knob body can drive the anvil assembly to move axially along the stapler and approach the cartridge. After the resistance received by the knob reaches the resistance preset value, the clutch member cannot drive the knob body to rotate. At this time, the knob assembly enters a failure mode, and the gap between the anvil assembly and the cartridge remains unchanged, without over-compressing the tissue.

[0077] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can be made, and all should be regarded as belonging to the protection scope of the present invention.

Claims

1. A knob assembly, characterized in that, For a circular tube stapler, a lead screw is arranged inside the stapler; the knob assembly includes: A knob body sleeved outside the lead screw. A driving member is arranged on the knob body. A first fitting portion is arranged on the proximal end face of the driving member. The first fitting portion includes at least one first fitting member arranged on the proximal end face of the driving member. When the knob body rotates, it drives the lead screw to move along the axial direction of the stapler. The first fitting member includes a first side face and a second side face. The first side face inclines towards a first direction. The second side face is a right-angle face, or the second side face inclines towards a second direction, and the inclination degree of the second side face is less than that of the first side face; A clutch member located at the proximal end of the driving member and arranged outside the driving member. A second fitting portion is arranged on the distal end face of the clutch member. The second fitting portion includes second fitting members corresponding to the first fitting members one by one. The second fitting portion can axially move relative to the first fitting portion. When the second fitting portion is in contact and cooperation with the first fitting portion, the rotation of the clutch member drives the knob body to rotate. The second fitting member includes a third side face and a fourth side face; A knob rear cover located at the proximal end of the knob body, and a compression spring is arranged between the proximal end face of the knob rear cover and the clutch member; Wherein, the first fitting member is a first protrusion, and the second fitting member is a second protrusion or a groove; or, the first fitting member is a groove, and the second fitting member is a protrusion; Wherein, when the clutch member rotates along the first direction under an external force, the first side face is in contact and cooperation with the third side face; when the clutch member rotates along the second direction under an external force, the second side face of the first fitting member is in contact and cooperation with the fourth side face of the second fitting member.

2. The knob assembly according to claim 1, wherein, Both the first side face of the first fitting member and the third side face of the second fitting member are planes or mating curved surfaces. Both the second side face of the first fitting member and the fourth side face of the second fitting member are planes or mating curved surfaces.

3. The knob assembly according to claim 1, characterized in that, The clutch member includes a clutch ring sleeved outside the knob body.

4. The knob assembly according to claim 1, wherein, The stapler further includes a knob housing, and a fourth fitting portion is arranged on the inner surface of the knob housing; The clutch member is located inside the knob housing. A third fitting portion is arranged on the side face of the clutch member. The third fitting portion is in cooperation with the fourth fitting portion so that the knob housing can drive the clutch member to rotate, and the clutch member can axially move relative to the knob housing.

5. The knob assembly according to claim 4, wherein The third fitting portion includes at least one orientation groove located on the side face of the clutch member. The fourth fitting portion includes orientation ribs corresponding to the orientation grooves one by one. The orientation ribs extend along the axial direction of the stapler and extend into the orientation grooves, and the orientation grooves can move along the extending direction of the orientation ribs.

6. The knob assembly according to claim 4, wherein, The third fitting portion includes at least one orientation rib located on the side face of the clutch member. The fourth fitting portion includes orientation grooves corresponding to the orientation ribs one by one. The orientation ribs extend along the axial direction of the stapler and extend into the orientation grooves, and the orientation ribs can move along their own extending directions.

7. The knob assembly according to claim 4, wherein The inner surface of the knob housing is provided with a stepped portion, and the stepped portion is located at the distal end surface of the clutch member.

8. The knob assembly according to claim 1, characterized in that, The distal end of the knob back cover is provided with an internal thread of the back cover, and the proximal end of the knob body is provided with an external thread of the body that mates with the internal thread of the back cover.

9. A circular tube type stapler, characterized in that, It includes the knob assembly according to any one of claims 1 to 8.

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