Transmission mechanism with self-checking function

Abstract

The present application relates to a kind of transmission mechanism with self-checking function, the transmission mechanism is arranged in the anastomat body of electric anastomat;The front end of the anastomat body is slidably installed with driver, and driver is connected with the anastomosis and cutting assembly provided with electric anastomat;The transmission mechanism includes: rack;Stroke buffer structure;Motor assembly;And main PCBA board;With the transmission mechanism with self-checking ability, it can be ensured that motor assembly can work normally before really firing anastomosis and cutting assembly, improve safety.Transmission mechanism adopts motor output gear and is transmitted with rack cooperation, and the number of link member of transmission mechanism is less, effectively reduce the influence of friction between link member, movement interference on transmission efficiency, ensure that high transmission rate is guaranteed while ensuring transmission stability.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and more particularly to a transmission mechanism with a self-testing function. Background Technology

[0002] Minimally invasive surgery aims to achieve the same high-quality results as open surgery with minimal or no trauma and minimal disruption to the patient's internal environment (local or systemic). Anastomosing devices, as a type of minimally invasive surgical instrument, are commonly used for tissue cutting and suturing in some surgical procedures. Existing anastomosing devices are divided into two types: manually fired and electrically fired. Manual firing involves pressing a handle to mechanically transmit force to the anastomosis assembly, requiring significant firing force to complete the anastomosis and placing extremely high demands on the operator. Insufficient firing force can lead to incomplete tissue cutting and closure, resulting in surgical accidents.

[0003] Current electrically operated staplers primarily convert the rotational motion of an internal motor into the desired motion via a transmission mechanism, enabling the cutting and closing of tissue by the anastomosis component. If the motor malfunctions during stapler use, it can pose surgical risks. Since the operation of the stapler motor inherently implies the use of the anastomosis component, detecting motor malfunctions before the stapler is put into use can effectively improve surgical safety and prevent potential surgical accidents. Summary of the Invention

[0004] The purpose of this invention is to provide a transmission mechanism with a self-testing function, which can confirm whether the motor assembly is working properly before the stapler is fired.

[0005] This invention is achieved through the following technical solution:

[0006] A transmission mechanism with a self-checking function is disposed inside the stapler body of an electric stapler;

[0007] A driver is slidably mounted on the front end of the stapler body, and the driver is connected to the cutting component of the electric stapler.

[0008] The transmission mechanism includes:

[0009] The rack extends in the front-to-back direction;

[0010] The rack and pinion mechanism, through which the drive unit is connected, features a stroke buffer structure.

[0011] The motor assembly, in conjunction with the rack and pinion drive, drives the rack to move back and forth; and

[0012] The main PCBA board divides the rack's travel stroke into at least two parts: a cutting stroke and a self-test stroke, in the front-to-back direction.

[0013] When the rack moves back and forth within the self-test stroke, it is used to detect whether the motor assembly is operating effectively and the stroke buffer structure ensures that the driver will not be displaced. When the rack moves forward during the kissing stroke, the rack drives the driver to move forward through the stroke buffer structure and completes the firing. When the rack returns to the initial position after the kissing stroke and the self-test stroke, it drives the driver and the kissing assembly to return to the initial position.

[0014] Compared with previous technologies, the beneficial effects of the present invention are as follows:

[0015] 1. By utilizing a transmission mechanism with self-testing capabilities, it is possible to ensure that the motor assembly can function normally before the actual slicing component is fired, thereby improving safety.

[0016] 2. The transmission mechanism uses a combination of motor output gear and rack for transmission, and the transmission mechanism has a small number of links, which effectively reduces the impact of friction and motion interference between links on transmission efficiency, ensuring both high transmission efficiency and transmission stability.

[0017] 3. The transmission mechanism is simple in composition, with small and few parts, and occupies little space, which is conducive to the miniaturization design of instruments. Attached Figure Description

[0018] Figure 1 This is a rendering of the present invention installed inside the anastomosis device.

[0019] Figure 2 This is a diagram showing the fit and connection relationships of some components of the present invention;

[0020] Figure 3 This is a structural diagram of the rack and its travel self-checking block.

[0021] Figure 4 A rendering showing the effect when the main PCBA board is located at the top inside the stapler body;

[0022] Figure 5 This is a structural diagram of the rack and its travel self-checking block.

[0023] Figure 6 A rendering showing the effect when the main PCBA board is located on the side inside the stapler body;

[0024] Figure 7 This is a schematic diagram of the disassembly and assembly connection structure of the rack and pinion and the stroke self-checking block;

[0025] Figure 8 This is a structural diagram of an electric stapler using the transmission mechanism of the present invention;

[0026] Figure 9 A schematic diagram of the first embodiment of the driver and the stroke self-test block;

[0027] Figure 10This is a schematic diagram of a second embodiment of the driver and the stroke self-test block;

[0028] Figure 11 Structural diagram of the pointer pull hook limit safety connecting pin;

[0029] Figure 12 for Figure 11 A magnified view of the center pointer hook and the safety connecting pin;

[0030] Figure 13 A structural diagram showing the pointer pull hook without the limit safety connecting pin.

[0031] Figure 14 for Figure 13 A magnified view of the center pointer hook and the safety connecting pin.

[0032] Labeling Explanation: 1 Outer Sheath, 2 Driver, 21 First Connecting Hole, 22 Second Empty Stroke Slot, 3 Connecting Shaft, 4 Rack, 401 Stroke Self-Check Block, 411 Raised Rib, 412 Receiving Slot, 413 First Empty Stroke Slot, 413a Front Side Point, 413b Rear Side Point, 414 Channel, 415 Second Connecting Hole, 42 Slot, 421 Insert Block, 5 Lead Screw, 6 Main PCBA Board, 61 Kissing Termination Switch, 62 Self-Check Kissing Critical Switch, 63 Initial Switch, 7 Anastomosing Device Body, 71 Firing Handle, 8 Adjusting Nut, 9 Rack Cover, 10 Safety Connecting Pin, 11 Stop Block, 12 Firing Button, 13 Firing PCBA Board, 14 Motor Assembly, 141 Gear, 15 Kissing Assembly, 16 Pointer Hook, 17 Indicator Pin, 18 Push Block, 19 Return Spring. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description:

[0034] like Figures 1 to 14 As shown, a transmission mechanism with a self-checking function is provided inside the stapler body 7 of an electric stapler;

[0035] The front end of the stapler body 7 is slidably mounted with a driver 2, which is connected to the cutting component of the electric stapler.

[0036] The transmission mechanism includes:

[0037] Rack 4 extends in the front-to-back direction;

[0038] The rack 4 is connected to the driver 2 via a stroke buffer structure.

[0039] Motor assembly 14, in transmission cooperation with rack 4, drives rack 4 to move back and forth; and

[0040] The main PCBA board 6 divides the running stroke of the rack 4 into at least a cutting stroke and a self-test stroke in the front-to-back direction;

[0041] When the rack 4 moves back and forth within the self-test stroke, it is used to detect whether the motor assembly is operating effectively and the stroke buffer structure ensures that the driver 2 will not be displaced. When the rack 4 moves forward during the kissing stroke, the rack 4 drives the driver 2 to move forward through the stroke buffer structure and completes the firing. When the rack 4 returns to the initial position after the kissing stroke and the self-test stroke, it drives the driver 2 and the kissing assembly to return to the initial position.

[0042] It should be noted that the front end of the stapler body 7 is connected to an outer sheath 1, and the driver 2 is slidably installed inside the outer sheath 1. The outer sheath 1 and the driver 2 are located on the first axis inside the stapler body 7; the rack 4 is located on the second axis inside the stapler body 7, and the first axis and the second axis are parallel.

[0043] like Figure 9 As shown, in the first embodiment of the driver and stroke self-test block:

[0044] The stroke buffer structure includes a connecting shaft 3 and a first empty stroke groove 413;

[0045] The connecting shaft 3 is mounted on the driver 2 which has a first connecting hole 21;

[0046] The first empty travel groove 413 is provided on the rack 4, the connecting shaft 3 passes through the first empty travel groove 413, and the connecting shaft 3 can move back and forth within the first empty travel groove 413.

[0047] Furthermore, a stroke self-test block 401 is provided at the front end of the rack 4; a first empty stroke slot 413 is provided on the stroke self-test block 401;

[0048] The stroke self-check block 401 is also provided with a protruding rib 411; the stroke self-check block 401 moves with the rack 4, causing the protruding rib 411 to move during the kissing stroke and the self-check stroke;

[0049] The travel self-test block 401 is provided with a receiving slot 412 for the driver 2 to pass through.

[0050] The first empty stroke groove 413 has a front point 413a and a rear point 413b at its front and rear ends, respectively. When the rack 4 moves back and forth within the self-test stroke, the motor assembly 14 rotates, driving the rack 4 to move forward or backward along the second axis, which in turn drives the stroke self-test block 401 to move forward or backward along the second axis. Due to the effect of the first empty stroke groove 413, the connecting shaft 3 reciprocates between the front point 413a and the rear point 413b of the first empty stroke groove 413. This makes the movement of the rack 4 during this process an empty stroke, used to check whether the motor assembly 14 is working properly. This process cannot drive the driver 2 to move. This empty stroke can be used to observe whether the transmission mechanism is operating normally before the actual firing and cutting engagement, improving safety.

[0051] like Figure 10 As shown, in the second implementation of the driver and stroke self-test block:

[0052] The stroke buffer structure is a connecting shaft 3 and a second empty stroke groove 22;

[0053] The connecting shaft 3 is mounted on the rack 4 and has a second connecting hole 415.

[0054] The second empty travel groove 22 is provided on the driver 2, the connecting shaft 3 passes through the second empty travel groove 22, and the connecting shaft 3 can move back and forth within the second empty travel groove 22.

[0055] Furthermore, the front end of the rack 4 is provided with a stroke self-checking block 401; the second connecting hole 415 is provided on the stroke self-checking block 401 of the rack 4, and the connecting shaft 3 is installed in the second connecting hole 415.

[0056] The stroke self-check block 401 is also provided with a protruding rib 411; the stroke self-check block 401 moves with the rack 4, causing the protruding rib 411 to move during the kissing stroke and the self-check stroke;

[0057] The travel self-test block 401 is provided with a receiving slot 412 for the driver 2 to pass through.

[0058] When rack 4 moves back and forth within its self-test stroke, motor assembly 14 rotates, causing rack 4 to move forward or backward along the second axis. This, in turn, causes stroke self-test block 401 to move forward or backward along the second axis. Meanwhile, connecting shaft 3 reciprocates within the second idle stroke groove 22. This idle stroke constitutes an idle stroke for checking whether motor assembly 14 is functioning correctly; it does not drive driver 2. This idle stroke allows observation of whether the transmission mechanism is operating normally before actual firing and cutting, improving safety.

[0059] In the two embodiments above, the axis of the connecting shaft 3 is perpendicular to the first axis and the second axis, respectively.

[0060] It should be noted that, based on embodiments 1 and 2, the main PCBA board 6 is provided with a kissing termination switch 61, a self-test kissing critical switch 62, and an initial switch 63 sequentially from front to back; a kissing stroke is formed between the kissing termination switch 61 and the self-test kissing critical switch 62, and a self-test stroke is formed between the self-test kissing critical switch 62 and the initial switch 63; the stroke self-test block 401 moves with the rack 4, driving the protruding rib 411 to move in the kissing stroke and the self-test stroke. The rear part of the driver 2 extends into the receiving groove 412, and the rear end face of the driver 2 can form a face contact with the inside of the receiving groove 412, using the end face force to achieve a stable and reliable effect, preventing the situation where the driver 2 fails during the secondary firing process, resulting in the inability to perform kissing and cutting.

[0061] like Figures 2 to 4 As shown, the stroke self-test block 401 can be located at the front end of the rack 4, and the protruding rib 411 is located at the top of the stroke self-test block 401; the main PCBA board 6 is located at the top inside the anastomosis device body 7, and is used to cooperate with the stroke self-test block 401 and the protruding rib 411.

[0062] like Figure 5 and Figure 6 As shown, the stroke self-test block 401 can be located at the front end of the rack 4, and the protruding rib 411 is located on the side of the stroke self-test block 401; the side of the main PCBA board 6 located inside the anastomosis device body 7 forms a cooperation with the stroke self-test block 401 and the protruding rib 411.

[0063] like Figure 7 As shown, for ease of production and assembly, the stroke self-test block 401 and the rack 4 are produced separately and then assembled, that is, the stroke self-test block 401 is installed on the rack 4 in a disassembled manner; the front end of the rack 4 is provided with a slot 42, and the stroke self-test block 401 is provided with a plug 421 that can be inserted into the slot 42.

[0064] On the other hand, the rack 4 and the stroke self-test block 401 are designed as a detachable structure. If the stroke self-test block 401 or the rack 4 alone has a problem, only one part can be replaced instead of replacing the entire rack 4 and the stroke self-test block 401, which can save costs.

[0065] Furthermore, the motor assembly 14 includes a motor and a gear 141 connected to the motor output shaft, with the gear 141 engaging with the rack 4. The transmission mechanism also includes a firing PCBA board 13, which is located within the firing handle 71 of the anastomosis device body 7. A firing button 12 is also installed on the firing handle 71. The firing PCBA board 13, the motor, and the main PCBA board 6 are connected. Pressing the firing button 12 triggers the firing PCBA board 13, thereby driving the motor. The structure of the motor and gear 141 is a conventional technique and will not be described in detail.

[0066] Furthermore, the stapler body 7 is equipped with a first safety device;

[0067] The first safety device includes a rack cover 9, a stop block 11, and a safety connecting pin 10; wherein, the rack cover 9 is located on the side of the rack 4 and the gear 141; a safety switch extending out of the anastomosis device body 7 is installed on the rack cover 9; the safety connecting pin 10 is located inside the firing handle 71; the safety switch is connected to the stop block 11 through the safety connecting pin 10; the stop block 11 is located between the firing PCBA board 13 and the firing button 12, and is used to prevent the firing button 12 from contacting the firing PCBA board 13;

[0068] By toggling the safety switch, the safety connecting pin 10 moves the stop block 11, thereby disengaging the stop block 11 from blocking the firing button 12, allowing the firing button 12 to contact the firing PCBA board 13.

[0069] The stapler body 7 is equipped with a second safety device;

[0070] The second safety device includes a lead screw 5, an adjusting nut 8, and a pointer hook 16. The adjusting nut 8 is rotatably mounted on the rear end of the stapler body 7, and the lead screw 5 is rotatably mounted inside the stapler body 7, with its rear end extending out of the stapler body 7 and threadedly connected to the adjusting nut 8. The pointer hook 16 is mounted inside the stapler body 7 in a back-to-back sliding manner, and the pointer hook 16 is limitedly connected to the safety connecting pin 10 to prevent the movement of the safety switch and the safety connecting pin 10. The lead screw 5 and the pointer hook 16 work together so that rotating the adjusting nut 8 can move the lead screw 5 backward while simultaneously moving the pointer hook 16 backward, causing the pointer hook 16 to disengage from the limited connection with the safety connecting pin 10.

[0071] It should be noted that the second safety device also includes an indicator needle 17 connected to the pointer hook 16, a push block 18 cooperating with the lead screw 5, and a return spring 19; wherein, the indicator needle 17 extends out of the anastomosis device body 7, and the indicator needle 17 cooperates with the green marking area provided on the outside of the anastomosis device body 7. In the initial state, the indicator needle 17 is not in the green marking area, indicating that the safety switch cannot be turned; rotating the adjusting nut 8 can allow the pointer hook 16 to move the indicator needle 17 to the green marking area, which is used to indicate that the safety switch can be turned;

[0072] The pointer hook 16 includes a horizontal extension piece and a vertical extension piece vertically connected to the rear end of the horizontal extension piece, so that the pointer hook 16 has an L-shaped structure; the front end of the horizontal extension piece is limitedly connected to the safety connecting pin 10, and the vertical extension piece has a slot for the lead screw 5 to pass through.

[0073] The push block 18 is fixedly connected to the lead screw 5, and the push block 18 is located on the front side of the vertical extension piece of the pointer hook 16; the return spring 19 is sleeved on the outer periphery of the lead screw 5 and located at the rear end of the vertical extension piece of the pointer hook 16. Rotating the adjusting nut 8 can drive the lead screw 5 and the push block 18 to move backward, so that the push block 18 pushes the pointer hook 16 to move backward and squeezes the return spring 19, thereby causing the pointer hook 16 to disengage from the limiting connection with the safety connecting pin 10; rotating the adjusting nut 8 in the opposite direction can drive the lead screw 5 and the push block 18 to move forward, while the return spring 19 pushes the pointer hook 16 forward, thereby restoring the pointer hook 16 to the limiting connection with the safety connecting pin 10.

[0074] Furthermore, the driver 2 is provided with a connecting hole, through which the driver 2 is connected to the connecting shaft 3. The connecting shaft 3 connects the connecting hole on the driver to the protruding rib 411 on the rack 4 travel self-test block 401, thereby realizing the connection between the driver 2 and the rack 4.

[0075] Furthermore, the transmission mechanism also includes a firing PCBA board 13; the firing PCBA board 13 is connected to the firing button 12 and the motor assembly 14 respectively; the firing PCBA board 13 is triggered by pressing the firing button 12, thereby driving the motor assembly 14 to work.

[0076] In summary, when using it:

[0077] In any embodiment, after the present invention is powered on, since the safety switch is in the initial state, the motor assembly 14 is working. When the rack 4 moves back and forth within the self-test stroke, the motor assembly 14 rotates, causing the rack 4 to move forward or backward along the second axis. This, in turn, causes the stroke self-test block 401 to move forward or backward along the second axis. Due to the effect of the first empty stroke groove 413, the connecting shaft 3 will only reciprocate between the front point 413a and the rear point 413b of the first empty stroke groove 413 during this process. This makes the movement of the rack 4 during this process an empty stroke, used to check whether the motor assembly 14 is working. After the self-test is completed, the protruding rib 411 on the rack 4 can stop at any position between switches 62 and 63, that is, at any position within the self-test stroke.

[0078] Then, the safety switch is turned on, and the firing button 12 is operated to make the rack 4 move in the cutting stroke. During this process, the connecting shaft 3 abuts against the rear point 413b of the first empty stroke groove 413. The motor assembly 14 rotates and drives the rack 4 to move forward along the second axis, which in turn drives the stroke self-test block 401 to move forward along the second axis. At this time, the stroke self-test block 401 can push the connecting shaft 3 to move forward, which in turn drives the driver 2 to move forward along the first axis in the anastomosis device body 7, so that the protruding rib 411 moves to the cutting termination switch 61 of the main PCBA board 6. The rack 4 drives the driver 2 to move forward through the stroke buffer structure and completes the firing, completing the cutting and anastomosis action. At this time, it can enter the pressure holding state.

[0079] Finally, the motor assembly 14 can be rotated in the opposite direction by controlling the firing button 12 again (or by setting the program), which will drive the rack 4 and driver 2 to retract. The rack 4 retracts after the kissing stroke and / or self-test stroke, and at the same time drives the driver 2 and the kissing assembly to retract. When the protruding rib 411 returns to the self-test kissing critical switch 62 or the initial switch 63, the motor stops, and the entire firing process is completed.

[0080] Although the present invention has been illustrated and described through specific embodiments and alternative methods, it should be understood that various changes and modifications may be made without departing from the spirit and scope of the invention. Therefore, it should be understood that the present invention is not limited in any sense except by the appended claims and their equivalents.

Claims

1. A transmission mechanism with a self-testing function, characterized in that, The transmission mechanism is located inside the stapler body (7) of the electric stapler; A driver (2) is slidably mounted on the front end of the stapler body (7), and the driver (2) is connected to the cutting component of the electric stapler. The transmission mechanism includes: The rack (4) extends in the front-to-back direction; The stroke buffer structure, the rack (4) cooperates with the driver (2) through the stroke buffer structure; The motor assembly (14) engages with the rack (4) in a transmission relationship and drives the rack (4) to move back and forth; and The main PCBA board (6) divides the running stroke of the rack (4) into at least a cutting stroke and a self-test stroke in the front-to-back direction; When the rack (4) moves back and forth within the self-test stroke, it is used to detect whether the motor assembly is operating effectively and the stroke buffer structure ensures that the driver (2) will not be displaced. When the rack (4) moves forward during the kissing stroke, the rack (4) drives the driver (2) to move forward through the stroke buffer structure and completes firing. When the rack (4) returns to the initial position after the kissing stroke and self-test stroke, it drives the driver (2) and the kissing assembly to return to the initial position.

2. The transmission mechanism with self-testing function according to claim 1, characterized in that: The stroke buffer structure includes a connecting shaft (3) and a first empty stroke groove (413); The connecting shaft (3) is mounted on the driver (2) which has a first connecting hole (21); The first empty travel groove (413) is provided on the rack (4), the connecting shaft (3) passes through the first empty travel groove (413), and the connecting shaft (3) can move back and forth in the first empty travel groove (413).

3. A transmission mechanism with self-testing function according to claim 1, characterized in that: The stroke buffer structure is a connecting shaft (3) and a second empty stroke groove (22); The connecting shaft (3) is mounted on the rack (4) and has a second connecting hole (415); The second empty travel groove (22) is provided on the driver (2), the connecting shaft (3) passes through the second empty travel groove (22), and the connecting shaft (3) can move back and forth in the second empty travel groove (22).

4. A transmission mechanism with self-testing function according to claim 2, characterized in that: The front end of the rack (4) is provided with a stroke self-test block (401); the first empty stroke groove (413) is provided on the stroke self-test block (401) of the rack (4); The stroke self-check block (401) is also provided with a raised rib (411); the stroke self-check block (401) moves with the rack (4), causing the raised rib (411) to move in the kissing stroke and the self-check stroke; The travel self-test block (401) is provided with a receiving slot (412) for the driver (2) to pass through.

5. A transmission mechanism with self-testing function according to claim 3, characterized in that: The front end of the rack (4) is provided with a stroke self-test block (401); the second connecting hole (415) is provided on the stroke self-test block (401) of the rack (4), and the connecting shaft (3) is installed in the second connecting hole (415); The stroke self-check block (401) is also provided with a raised rib (411); the stroke self-check block (401) moves with the rack (4), causing the raised rib (411) to move in the kissing stroke and the self-check stroke; The travel self-test block (401) is provided with a receiving slot (412) for the driver (2) to pass through.

6. A transmission mechanism with self-testing function according to claim 4 or 5, characterized in that: The travel self-test block (401) is installed on the rack (4) in a disassembly and assembly manner; the front end of the rack (4) is provided with a slot (42), and the travel self-test block (401) is provided with a plug (421) that can be inserted into the slot (42).

7. A transmission mechanism with self-testing function according to claim 1, characterized in that: The motor assembly (14) includes a motor and a gear (141) connected to the output shaft of the motor. The gear (141) is in transmission engagement with the rack (4).

8. A transmission mechanism with self-testing function according to claim 7, characterized in that: The transmission mechanism also includes a firing PCBA board (13), which is located inside the firing handle (71) of the anastomosis device body (7). A firing button (12) is also installed on the firing handle (71). The firing PCBA board (13), the motor and the main PCBA board (6) are connected. The firing PCBA board (13) is triggered by pressing the firing button (12), thereby driving the motor to work.

9. A transmission mechanism with self-testing function according to claim 8, characterized in that: The anastomosis device body (7) is equipped with a first safety device; The first safety device includes a rack cover (9), a stop (11), and a safety connecting pin (10); wherein, the rack cover (9) is located on the side of the rack (4) and the gear (141); a safety switch extending out of the anastomosis device body (7) is installed on the rack cover (9); the safety connecting pin (10) is located inside the firing handle (71); the safety switch is connected to the stop (11) through the safety connecting pin (10); the stop (11) is located between the firing PCBA board (13) and the firing button (12) to prevent the firing button (12) from contacting the firing PCBA board (13); By toggling the safety switch, the safety connecting pin (10) moves the stop (11), thereby disengaging the stop (11) from blocking the firing button (12) and allowing the firing button (12) to contact the firing PCBA board (13).

10. A transmission mechanism with self-testing function according to claim 9, characterized in that: The anastomosis device body (7) is equipped with a second safety device; The second safety device includes a lead screw (5), an adjusting nut (8), and a pointer hook (16). The adjusting nut (8) is rotatably installed at the rear end of the stapler body (7), and the lead screw (5) is rotatably installed inside the stapler body (7), with the rear end of the lead screw (5) extending out of the stapler body (7) and threadedly connected to the adjusting nut (8). The pointer hook (16) is installed inside the stapler body (7) in a forward-backward sliding manner, and the pointer hook (16) is limitedly connected to the safety connecting pin (10) to block the movement of the safety switch and the safety connecting pin (10). The lead screw (5) and the pointer hook (16) work together so that rotating the adjusting nut (8) can drive the lead screw (5) to move backward while simultaneously driving the pointer hook (16) to move backward, causing the pointer hook (16) to disengage from the limited connection with the safety connecting pin (10).

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