Transmission mechanism and surgical cutting and suturing device

Abstract

This invention discloses a transmission mechanism for a surgical cutting and suturing device, comprising: a drive gear having a first rotational central axis; a key gear having a second rotational central axis, wherein the key gear is provided with a communicating pin hole and a key hole, and the key gear meshes with the drive gear; a rack meshing with a rotating gear; a line connecting the first rotational central axis and the second rotational central axis is a central line, and a straight line intersecting the second rotational central axis and extending downward perpendicularly to the central line is a first dividing line; in response to the rack being at its farthest position and the key hole being located on the first dividing line of the key gear, the rack moves from its farthest position to its closest position, and the position of the key hole after rotating a certain angle is the second dividing line; in response to the rack being at its closest position, the key hole of the key gear is located in the part of the key gear away from the drive gear, and the key hole is not on either of the two dividing lines. The setting of the key hole position avoids the phenomenon of the firing handle getting stuck, ensuring the normal transmission of the transmission mechanism.

Description

Technical Field

[0001] This invention relates to the field of surgical instruments, and in particular to a transmission mechanism for a surgical cutting and suturing device and a surgical cutting and suturing device having the aforementioned transmission mechanism. Background Technology

[0002] Surgical staplers, such as laparoscopic staplers, are widely used in thoracic surgery, abdominal surgery, gynecology, and pediatric surgery because they allow for smaller incisions, facilitating postoperative recovery. Surgical staplers operate on the principle of a stapler, using staples to close and suture the incision during surgery. They are characterized by neat sutures, reliable suture strength, and good hemostasis.

[0003] Figure 1 , Figure 2 This is a partial structural diagram of an existing surgical cutting and suturing device.

[0004] like Figure 1 , Figure 2 As shown, the surgical cutting and suturing device 100's advance and retraction operations are achieved through the firing handle 118 cooperating with the transmission mechanism. The transmission mechanism includes a drive gear assembly 111, a key gear 112, a return gear 113, a pinion gear structure 116, and a rack 114. The drive gear assembly 111 includes a rotating gear 111a and a drive gear 111b coaxially arranged. The rotating gear 111a meshes with the rack 114, and the drive gear 111b meshes with the key gear 112. The key gear 112 is configured with... There are connecting pin holes 200 and key holes 201. A pin 198 with a key 199 slides through the reset gear 113 and the key gear 112. The pin 198 engages with the pin hole 200, and the key 199 engages with the key hole 201. The diameter of the drive gear 111b is smaller than the diameter of the key gear 112. The key gear 112 and the reset gear 113 are respectively located on opposite sides of the support of the surgical cutting and suturing device 100. Specifically, the key gear 112 is located on one side, and the reset gear 113 is located on the opposite side. Figure 2 As shown, the transmission mechanism also includes a pusher 60, a rod 61 mounted on the main body, and a tension spring 62. The tension spring 62 has a through hole 68. The end of the pusher 60 has an upwardly protruding finger-like portion 69 that passes through the through hole 68. A rack 114 is connected to a firing lever 21, which is connected to a cutting member 33. The rack 114 drives the firing lever 21 to move forward or backward, and the firing lever 21 drives the cutting member 33 to move forward or backward, thereby realizing the advance or retraction of the blade. The firing handle 118 includes a movable handle 81 and a sector gear 82. The sector gear 82 meshes with a reset gear 113, and the movable handle 81 is connected to the rod 61.

[0005] When the surgical cutting and suturing device 100 performs the infeed operation, the firing handle 118 moves along... Figure 2 Rotating counterclockwise in the middle rotates the movable handle 81, which drives the rod 61 to move forward. The tension spring 62 pulls the finger-shaped part 69 of the pusher 60 backward. The pusher 60 first rotates clockwise so that its front abutment part abuts against the recessed hole formed by the upward indentation at the bottom of the rack 114. That is, the pusher 60 rotates clockwise until it abuts against the rack 114. The rod 61 drives the pusher 60 to move forward and push the rack 114 forward. The rack 114 pushes the firing rod 21 forward, thereby causing the cutting component 33 to move towards the operating end 1. 17. When the rack 114 moves, it drives the rotating gear 111a to rotate, and the driving gear 111b rotates coaxially with the rotating gear 111a, which in turn drives the key gear 112 to rotate counterclockwise, and causes the letter wheel structure 116 to rotate to indicate the current usage status of the surgical cutter 100 to the user; during the complete cutting operation of the surgical cutter 100, the rack 114 is driven to move from the nearest position to the farthest position by the firing handle 118, and the rack 114 drives the key gear 112 in the transmission mechanism to rotate 180° counterclockwise.

[0006] When the surgical cutter 100 performs a retraction operation, the pin 198 slides axially to engage with the reset gear 113, and the key 199 can operably engage with the keyhole 201 of the reset gear 113 and the key gear 112. The reset gear 113 is driven to rotate clockwise by the firing handle 118, and the pin 198 rotates synchronously. The key 199, located on the pin 198, applies a force to the key gear 112 to rotate clockwise, causing the key gear 112 and the reset gear 113 to rotate clockwise synchronously, thereby driving the drive gear 111b and the rotating gear 111a to rotate, causing the rack 114 to move in the opposite direction to the operating end 117, thereby resetting the cutting member 33. During the complete retraction operation of the surgical cutter 100, the reset gear 113 and the key gear 112 are driven to rotate 180° clockwise by the firing handle 118, thereby moving the rack 114 from the farthest position to the nearest position.

[0007] In the existing technology, the firing handle of the surgical cutting and suturing device often gets stuck during use. In this case, a lot of force needs to be applied to the firing handle to turn it. In severe cases, the firing handle is stuck, making it impossible to retract the blade normally, which affects the normal use of the surgical cutting and suturing device and increases the risk of surgery.

[0008] The focus of this invention is to identify the causes affecting the normal rotation of the firing handle and to enable the operator of the surgical cutting and suturing device to apply a uniform force to the firing handle for normal cutting and retraction. Summary of the Invention

[0009] In view of the shortcomings of the prior art, the present invention aims to find out the cause of the jamming of the firing handle of the surgical cutting and suturing device, and based on the found cause, to provide a transmission mechanism and a surgical cutting and suturing device that solve the above-mentioned technical problems.

[0010] This invention provides an improved technical solution, a transmission mechanism for a surgical cutting and suturing device, the transmission mechanism comprising: A drive gear assembly, comprising a rotating gear and a drive gear arranged coaxially; Pins, keys; A key gear and a return gear are coaxially arranged. The key gear meshes with the drive gear. The key gear has a communicating pin hole and a key hole. The pin, which has the key, slides through the return gear and the key gear. The pin engages with the pin hole, and the key engages with the key hole. A rack that meshes with the rotating gear, the rack moving between a nearest and a farthest position, the key gear rotating by a certain angle in response to the movement of the rack between the nearest and farthest positions; The drive gear has a first rotational center axis, and the key gear has a second rotational center axis; the line connecting the first rotational center axis and the second rotational center axis is a center line, which is perpendicular to both the first and second rotational center axes; a straight line intersecting the second rotational center axis, perpendicular to the center line, and extending substantially downwards is a first dividing line; in response to the rack being at its farthest position and the keyhole being located on the first dividing line of the key gear, the rack moves from its farthest position to its closest position, and the position of the keyhole after rotating by the angle is a second dividing line; the first and second dividing lines divide the key gear into a portion far from the drive gear and a portion close to the drive gear; in response to the rack being at its closest position, the keyhole of the key gear is located in the portion of the key gear far from the drive gear, and the keyhole is not on the first or second dividing line.

[0011] Furthermore, in response to the movement of the rack between its nearest and farthest positions, the key gear rotates by an angle of 180°, and the second dividing line is a generally upward-extending straight line that intersects the second rotational center axis and is perpendicular to the line connecting the centers.

[0012] Furthermore, the surgical cutting and suturing device includes a firing handle, which is disposed below the reset gear and engages with the reset gear.

[0013] Furthermore, the firing handle includes a connected movable handle and a sector gear, the sector gear meshing with a reset gear.

[0014] The present invention also provides a surgical cutting and suturing device, which includes the transmission mechanism described above.

[0015] Furthermore, it also includes a handle assembly, a shaft assembly extending longitudinally from the handle assembly, and an end effector disposed at the distal end of the shaft assembly; the handle assembly includes a firing handle.

[0016] Furthermore, the end effector is provided with a movable cutting member that moves to cut tissue located in the end effector; a firing rod is provided within the rod assembly, the cutting member is connected to one end of the firing rod, and the other end of the firing rod is connected to one end of the rack; the rack moves between the nearest position and the farthest position, causing the cutting member to move between the initial position and the firing position.

[0017] This invention recognizes that if there is a position with the greatest force during the retraction process, the center distance between the key gear and the drive gear will decrease. This is the reason why the firing handle cannot rotate normally or even gets stuck. By changing the installation position of the key hole in the key gear of the transmission mechanism, the key gear and the drive gear can mesh normally during transmission, allowing the firing handle to rotate normally and preventing it from getting stuck. This ensures smooth retraction and allows the surgical cutting and suturing device to be used normally, thereby effectively reducing surgical risks. Attached Figure Description

[0018] Figure 1 This is a partial structural diagram of an existing surgical cutting and suturing device; Figure 2 This is a schematic diagram of the transmission mechanism of an existing surgical cutting and suturing device; Figure 3a and Figure 3b yes Figure 2 A schematic diagram of the gear components of the transmission mechanism of the surgical cutting and suturing device shown; Figure 4a This is a schematic diagram of the transmission mechanism in one embodiment of the present invention, where the rack is located at its furthest position and the key hole of the key gear is located at a position perpendicular to the center line S1 and extending upward. Figure 4b This is a schematic diagram of the transmission mechanism of an embodiment of the present invention, in which the rack is located at the closest position and the key hole of the key gear is located perpendicular to the center line S1 and extends downward. Figure 5a This is a schematic diagram of the transmission mechanism in one embodiment of the present invention, where the rack is located at its furthest position and the key hole of the key gear is located at a position perpendicular to the center line S1 and extending downward. Figure 5bThis is a schematic diagram of the transmission mechanism in one embodiment of the present invention, where the rack is located at the closest position and the key hole of the key gear is located at a position perpendicular to the center line S1 and extending upward. Figure 6 This is a schematic diagram of the transmission mechanism in Embodiment 2 of the present invention, where the rack is at its closest position and the keyhole of the key gear is on a horizontal line. Figure 7 This is a schematic diagram of the transmission mechanism when the three racks are in the closest position and the keyhole of the key gear is in a vertical line according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the transmission mechanism in an embodiment of the present invention, where the four racks are located at the closest positions and the key holes of the key gears are located on the extension line of the center line S1. Figure 9 This is a partial structural schematic diagram of the surgical cutting and suturing device of the present invention.

[0019] The reference numerals in the above figures are as follows: 100-Surgical cutting and suturing device; 118-Firing handle; 111-Drive gear assembly; 111a-Rotating gear; 111b-Drive gear; 112-Key gear; 113-Reset gear; 114-Rack; 116-Character wheel structure; 117-Operating end; 198-Pin; 199-Key; 200-Pin hole; 201-Key hole; 60-Pushing member; 61-Rod; 62-Tension spring; 68-Through hole; 69-Finger part; 21-Firing lever; 33-Cutting component; 81-Modible handle; 82-Sector-shaped belt gear; C1-First rotation center axis; C2-Second rotation center axis; S1-Center line; R1-First dividing line; R2-Second dividing line; S2-Horizontal line; S3-Center extension line; h-Vertical line. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0021] It is important to understand that the terms "proximal" and "distal" used in this article are relative to the clinician manipulating the stapler handle. The term "proximal" refers to the part closer to the clinician, while the term "distal" refers to the part farther from the clinician. That is, the handle is the proximal side, and the jaw assembly is the distal side. For example, the proximal end of a component refers to the end relatively closer to the handle, and the distal end refers to the end relatively closer to the jaw assembly.

[0022] The transmission process of a conventional surgical cutting and suturing device is as follows: During the advance, the rack moves from its nearest to its farthest position; during the retraction, the rack moves from its farthest to its nearest position, thereby causing the cutting component to move from the firing position to the initial position. When the rack reaches its farthest position, the keyhole of the key gear rotates to its uppermost position. During the retraction process, the firing handle drives the return gear to rotate clockwise, and the return gear, through a pin and a key, drives the key gear to rotate clockwise. After rotating a certain angle, the rack returns to its nearest position, and the keyhole is located at its lowest position. During the retraction process, the angular range between the starting and ending positions of the keyhole rotation is the rotation range of the keyhole. The starting position, ending position, and rotation range of the key rotation are all the same as those of the keyhole.

[0023] During the aforementioned retraction process, the key applies a force to the key gear, causing it to rotate clockwise. This rotational force has a component along the line connecting the rotation center of the key gear and the rotation center of the drive gear. This component exerts a force on the key gear along the connecting line. This force increases as the key rotates to... Figure 3a The force applied to the key gear along the connecting line in the fourth quadrant is the largest. This force causes the key gear to move toward the drive gear, reducing the center distance between the two gears. This results in the key gear teeth meshing too tightly with the drive gear teeth, preventing the key gear teeth from properly disengaging from the drive gear teeth. Consequently, the gear surfaces cannot mesh properly, preventing the key gear from rotating normally. The firing handle is jammed due to the interruption of gear transmission, and the drive gear cannot properly drive the rack, thus preventing normal tool return.

[0024] The transmission process of the surgical cutting and suturing device: During the advance, the rack 114 moves from its nearest position to its farthest position; during the retraction, the rack 114 moves from its farthest position to its nearest position, thereby causing the cutting component to move from the firing position to the initial position. Throughout the entire process of retraction or advance, the key gear rotates 180°. For example... Figure 3a As shown, in the prior art, when the rack 114 moves to its furthest position, the keyhole 201 of the key gear 112 rotates to its uppermost position. It should be noted that when the rack 114 is at its furthest position, the keyhole 201 is at the starting point of rotation, corresponding to the starting position of the retraction. During the retraction process, the firing handle 118 drives the reset gear 113 to rotate clockwise. The reset gear 113, through the pin 198 and key 199, drives the key gear 112 to rotate clockwise. After rotating 180°, as... Figure 3bAs shown, the tool retraction is complete, rack 114 returns to its closest position, and keyhole 201 is at its lowest position. It should be noted that when rack 114 is at its closest position, tool retraction is complete, and keyhole 201 is at the end point of rotation. During the tool retraction process, the angular range between the starting and ending positions of keyhole 201's rotation is the rotation range of keyhole 201. The starting position, ending position, and rotation range of key 199 are the same as those of keyhole 201. During the above tool retraction process, key 199 applies a force to key gear 112, causing it to rotate clockwise. Starting from the starting position of keyhole 201's rotation, when key 199 rotates clockwise to... Figure 3a and Figure 3b In the fourth quadrant, the rotational force has a component along the line S1 connecting the rotation center of the key gear 112 and the rotation center of the drive gear 111b. This component exerts a force on the key gear 112 along the center line S1, causing the key gear 112 to move towards the drive gear 111b. When the key 199 rotates to a position perpendicular to the connecting line S1, the rotational force is fully applied to the center line S1. It should be noted that when the key 199 rotates to... Figure 3a and Figure 3b When the key gear 112 is positioned perpendicular to the center line S1 in the fourth quadrant, the rotational force exerted on it along the center line S1 is at its maximum. This force causes the key gear 112 to move toward the drive gear 111b, reducing the center distance between the two gears. This results in the teeth of the key gear 112 meshing too tightly with the tooth grooves of the drive gear 111b. The teeth of the key gear 112 cannot properly disengage from the tooth grooves of the drive gear 111b, causing the gear surfaces to not mesh properly. Consequently, the key gear 112 cannot rotate normally, and the firing handle 118 is jammed due to the interruption of transmission. The drive gear 111b cannot properly drive the rack 114 to move, thus preventing the tool from returning to its original position.

[0025] Therefore, in the existing assembly method of key gears, during the retraction process, the force of the key on the key gear reduces the center distance between the two gears, thereby affecting the meshing of the gear surfaces. The gear transmission is jammed, which causes the firing handle to be jammed. A large force needs to be applied to the firing handle to complete the retraction. In severe cases, the gear transmission is completely jammed, and the firing handle is stuck.

[0026] This invention discloses a structure for preventing the firing handle in a transmission mechanism from jamming. The transmission mechanism includes: a drive gear assembly comprising a rotating gear and a driving gear coaxially arranged; a key gear and a return gear coaxially arranged, the key gear meshing with the driving gear, the key gear having a communicating pin hole and a key hole, a pin for which a key slides through the return gear and the key gear, the pin and key engaging with the pin hole and key hole respectively; and a rack meshing with the rotating gear, the rack moving between a nearest position and a farthest position, the key gear rotating a certain angle in response to the rack's movement between the nearest and farthest positions; the driving gear having a first rotational center axis, and the key gear having a second rotational center axis; the first rotational center axis to the second… The line connecting the two rotational axes is the center line, which is perpendicular to both the first and second rotational axes. A straight line intersecting the second rotational axis and extending approximately downwards perpendicular to the center line is the first dividing line. In response to the rack being at its farthest position and the keyhole being located on the first dividing line of the key gear, the rack moves from its farthest position to its closest position. The position of the keyhole after rotating a certain angle is the second dividing line. The first and second dividing lines divide the key gear into a part far from the driving gear and a part close to the driving gear. In response to the rack being at its closest position, the keyhole of the key gear is located in the part of the key gear far from the driving gear, and the keyhole is not on the first or second dividing line.

[0027] Specific Embodiment 1: The present invention also provides an improved technical solution. Please refer to... Figures 4a-4b This embodiment provides a transmission mechanism for a surgical cutting and suturing device 100. The drive gear 111b has a first rotational central axis C1, and the key gear 112 has a second rotational central axis C2. A perpendicular line connecting the first rotational central axis C1 to the second rotational central axis C2 is defined as the center line S1. A straight line perpendicular to both the second rotational central axis C2 and the center line S1 is defined as the first dividing line. Figure 4a The first dividing line extending roughly downwards is R1, along... Figure 4aThe second dividing line, R2, extends roughly upwards. The first dividing line R1 and the second dividing line R2 divide the key gear 112 into two parts. The first rotational axis C1 is parallel to the second rotational axis C2, and the connecting line S1 is perpendicular to both the first and second rotational axes C1 and C2. The determination of the second dividing line R2 is based on the fact that the keyhole rotates 180 degrees during the rack's movement from its furthest position to its closest position. Based on this, regardless of whether the keyhole's rotation angle is 180 degrees, once the position of the first dividing line R1 is determined, in response to the rack being at its furthest position and the keyhole being positioned on the first dividing line R1 of the key gear, the position of the keyhole after rotating the rack from its furthest position to its closest position is the second dividing line R2. Furthermore, the first dividing line R1 and the second dividing line R2 divide the key gear into a part far from the drive gear and a part close to the drive gear.

[0028] Compared to existing technologies, in this invention, when installing the key gear 112, rotating the key gear 112 causes a change in the position of the keyhole 201, such as... Figures 4a-4b The illustration shows a configuration of keyhole 201 and key 199, wherein... Figure 4a The initial retraction state is shown. Figure 4b The diagram shows the completed retraction state, which is the critical state with the greatest force. It also shows the location of the keyhole that results in the greatest force. When the rack 114 moves to its furthest position, the center line of the keyhole 201 roughly coincides with the second dividing line R2. This can be described as the keyhole 201 being located on the second dividing line R2, or the key 199 being located on the second dividing line R2. During the subsequent retraction process, the firing handle 118 drives the reset gear 113 to rotate clockwise. The reset gear 113, through the pin 198 and the key 199, drives the key gear 112 to rotate clockwise. After the pin 198, key 199, and key gear 112 rotate 180°, the rack 114 moves to its closest position, completing the retraction. The center line of the keyhole 201 roughly coincides with the first dividing line R1. This can be described as the keyhole 201 being located on the first dividing line R1, or the key 199 being located on the first dividing line R1. When key 199 is located at the first dividing line R1, the force exerted by key 199, which is housed in key hole 201, on key gear 112 along the center line S1 is the greatest. This force minimizes the center distance between the two gears to the greatest extent and has the greatest impact on the meshing transmission of the two gears.

[0029] like Figures 5a-5bAnother configuration of the keyhole 201 and key 199 is shown. When the rack 114 moves to its furthest position, both the keyhole 201 and key 199 are located at the first dividing line R1. During the retraction process, the firing handle 118 drives the reset gear 113 to rotate clockwise. The reset gear 113 drives the key gear 112 to rotate clockwise via the pin 198 and key 199. After rotating 180°, when the rack 114 moves to its closest position, the retraction is complete, and both the keyhole 201 and key 199 are located at the second dividing line R2. Figure 5a In the initial state of the retraction shown, when the key 199 is located at the first dividing line R1, the key 199, which is housed in the key hole 201, exerts the maximum force on the key gear 112 along the center line S1. This force minimizes the center distance between the two gears to the greatest extent and has the greatest impact on the meshing transmission of the two gears.

[0030] During retraction, the key gear 112 rotates clockwise. Therefore, during the entire retraction process, as the key gear 112 rotates 180 degrees clockwise, the position where the key 199 exerts the greatest force on the key gear 112 along the center line S1 is the first dividing line R1. During assembly, the key 199, which is housed in the keyhole 201, should avoid this position, and correspondingly, the keyhole 201 should also avoid this position. The first dividing line R1 and the second dividing line R2 divide the key gear 112 into two parts: the part away from the drive gear 111b and the part close to the drive gear 111b. In the surgical cutting and suturing device of the present invention, when the rack 114 is in the closest position, and the key gear 112 is assembled, the key hole 201 of the key gear 112 is set in the part of the key gear 112 away from the drive gear 111b when the rack 114 is in the closest position, and the key hole 201 is not located on the first dividing line R1 or the second dividing line R2, that is, it is set to avoid the first dividing line R1 and the second dividing line R2. With the above arrangement, during the retraction process, the key 199 in the key hole 201 avoids the position that applies the maximum force to the key gear 112 along the center line S1, so that the movement of the key gear 112 toward the drive gear 111b is not too large, the decrease in center distance is not too large, and the influence of the key 199 in the key hole 201 on the meshing transmission of the two gears is not too large, thus avoiding the key gear 112 from getting stuck with the drive gear 111b.

[0031] Specific Implementation Example 2: As shown in the example Figure 6As shown, the horizontal line S2 extends horizontally away from the drive gear 111b and perpendicular to the second rotation center axis C2. During assembly of the surgical cutting and suturing device, the rack 114 is in its closest position. When assembling the key gear 112, the keyhole 201 of the key gear 112 is positioned on the horizontal line S2 of the key gear 112 when the rack 114 is in its closest position. Since the keyhole 201 is in this position at the initial feed position, the force exerted by the key 199 in the keyhole 201 along the center line S1 on the key gear 112 during the retraction process is relatively small. This results in a smaller movement of the key gear 112 towards the drive gear 111b, a smaller decrease in the center distance, and a smaller impact of the key 199 in the keyhole 201 on the meshing transmission of the two gears.

[0032] The other structures are the same as in Embodiment 1.

[0033] Specific Implementation Example 3: As shown in the example Figure 7 As shown, the line perpendicular to the second rotation center axis C2 and extending vertically upward is the vertical line h. During assembly of the surgical cutting and suturing device, the rack 114 is in its closest position. When assembling the key gear 112, the keyhole 201 of the key gear 112 is positioned on the vertical line h when the rack 114 is in its closest position. At the initial infeed position, the keyhole 201 is in this position. During the retraction process, the key 199 in the keyhole 201 exerts a smaller force on the key gear 112 along the center line S1, resulting in a smaller movement of the key gear 112 towards the drive gear 111b, a smaller decrease in the center distance, and a smaller impact of the key 199 in the keyhole 201 on the meshing transmission of the two gears.

[0034] The other structures are the same as in Embodiment 1.

[0035] Specific Implementation Example 4: As shown in the example Figure 8 As shown, the line connecting the first rotational axis C1 to the second rotational axis C2 is the center line S1, and the line extending from the center line S1 away from the drive gear 111b is the center extension line S3. During assembly of the surgical cutting and suturing device, the rack 114 is in the closest position. When assembling the key gear 112, the keyhole 201 of the key gear 112 is positioned on the center extension line S3 when the rack 114 is in the closest position. At the initial infeed position, the keyhole 201 is in this position. During the retraction process, the key 199 in the keyhole 201 exerts a small force on the key gear 112 along the center line S1, resulting in a small movement of the key gear 112 towards the drive gear 111b and a small decrease in the center distance. Therefore, the key 199 in the keyhole 201 has a small impact on the meshing transmission of the two gears.

[0036] The other structures are the same as in Embodiment 1.

[0037] like Figure 9As shown, the present invention also provides a surgical cutting and suturing device 100, which includes the transmission mechanism described above. The surgical cutting and suturing device 100 further includes a handle assembly, a shaft assembly extending longitudinally from the handle assembly, and an end effector disposed at the distal end of the shaft assembly; the end effector has a movable cutting member 33, the shaft assembly has a firing lever 21, and the handle assembly includes a firing handle 118. The cutting member 33 is used to cut tissue located in the end effector. One end of the firing lever 21 is connected to the cutting member 33, and the other end of the firing lever 21 is connected to a rack 114. The rack 114 drives the firing lever 21 to move forward or backward, and the firing lever 21 drives the cutting member 33 to move forward or backward, thereby achieving cutting advance or retraction. The firing handle 118 includes a movable handle 81 and a sector gear 82, which meshes with a reset gear 113, causing the cutting member 33 to move between an initial position and a firing position.

[0038] This invention is the first in the art to recognize that the reason the firing handle cannot rotate normally is that the key gear and the drive gear are stuck. During the retraction process, the center distance between the key gear and the drive gear decreases too much, meaning the key gear moves too far toward the drive gear, which is a major reason for the sticking. Based on this, this invention further determines that the force exerted on the key gear is greatest when the key rotates to a certain position. This force causes the key gear to move the greatest distance toward the drive gear, which is the specific reason for the gear sticking. Having identified the reasons why the firing handle cannot rotate normally, and the major and specific reasons for gear sticking, this invention is the first to propose setting the key hole of the key gear in a reasonable position during assembly, so that it avoids the position where the force exerted on the key gear is greatest during the retraction process, thereby preventing the key gear from sticking with the drive gear and allowing the firing handle to rotate normally. Finding the reasons why the firing handle cannot rotate normally, and the major and specific reasons for gear sticking, is the result of the inventors' creative labor.

[0039] In summary, in this invention, the dividing lines R1 and R2 of the key gear of the surgical cutting and suturing device divide the key gear 112 into a part close to the driving gear and a part far away from the driving gear. When the rack 114 moves to the closest position, the key hole 201 is located in the part of the key gear 112 far away from the driving gear 111b, and the key hole 201 is not on the dividing lines R1 and R2. The aforementioned location of the key hole 201 ensures that during the retraction process, the key 199 in the key hole 201 avoids the position of the maximum force applied to the key gear 112 along the center line S1, thereby reducing the amplitude of the key gear 112 moving towards the driving gear 111b, reducing the amplitude of the change in the center distance, and reducing the influence of the key 199 in the key hole 201 on the meshing transmission of the two gears. This prevents the key gear 112 from getting stuck with the driving gear 111b, ensuring normal meshing of the key gear 112 and the driving gear 111b, and guaranteeing normal transmission.

[0040] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0041] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A transmission mechanism for a surgical cutting and suturing device, the transmission mechanism comprising: A drive gear assembly, comprising a rotating gear and a drive gear arranged coaxially; Pins, keys; A key gear and a reset gear are coaxially arranged. The key gear meshes with the drive gear. The key gear is provided with a communicating pin hole and a key hole. The pin with the key slides through the reset gear and the key gear. The pin engages with the pin hole and the key hole, respectively. as well as A rack that meshes with the rotating gear, the rack moving between a nearest and a farthest position, the key gear rotating by a certain angle in response to the movement of the rack between the nearest and farthest positions; The key gear is characterized in that the drive gear has a first rotational center axis, and the key gear has a second rotational center axis; the line connecting the first rotational center axis and the second rotational center axis is a center line, the center line is perpendicular to both the first and second rotational center axes, and a straight line intersecting the second rotational center axis, perpendicular to the center line, and extending downwards is a first dividing line; in response to the rack being at its farthest position and the key hole being located on the first dividing line of the key gear, the rack moving from its farthest position to its closest position, the position of the key hole after rotating by the angle is a second dividing line, and the first and second dividing lines divide the key gear into a portion far from the drive gear and a portion close to the drive gear; In response to the rack being in its closest position, the keyhole of the key gear is located in the portion of the key gear furthest from the drive gear, and the keyhole is not on the first dividing line and the second dividing line.

2. The transmission mechanism according to claim 1, characterized in that, In response to the movement of the rack between its nearest and farthest positions, the key gear rotates by an angle of 180°, and the second dividing line is a straight line extending upwards, intersecting the second rotation center axis and perpendicular to the line connecting the centers.

3. The transmission mechanism according to claim 1, characterized in that, The surgical cutting and suturing device includes a firing handle disposed below the reset gear and engaged with the reset gear.

4. The transmission mechanism according to claim 3, characterized in that, The firing handle includes a connected movable handle and a sector gear, which meshes with a reset gear.

5. A surgical cutting and suturing device, characterized in that, The surgical cutting and suturing device includes the transmission mechanism as described in any one of claims 1-4.

6. The surgical cutting and suturing device according to claim 5, characterized in that, It also includes a handle assembly, a shaft assembly extending longitudinally from the handle assembly, and an end effector disposed at the distal end of the shaft assembly; the handle assembly includes a firing handle.

7. The surgical cutting and suturing device according to claim 6, characterized in that, The end effector has a movable cutting member that moves to cut tissue located in the end effector; the rod assembly has a firing rod, the cutting member is connected to one end of the firing rod, and the other end of the firing rod is connected to one end of the rack; the rack moves between the nearest position and the farthest position, causing the cutting member to move between the initial position and the firing position.

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