Surgical robot main hand tools

Abstract

The present invention discloses a surgical robot main hand tool, comprising a housing connectable to a main hand; a motor is arranged in the housing; a motor shaft of the motor is fixedly connected to a first control block; a motor body of the motor is fixedly connected to a second control block, and an encoder is fixed to the lower part of the motor. The surgical robot main hand tool of the present invention has a simple structure and is easy to operate.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices and relates to a main control mechanism of a surgical robot. Background Art

[0002] CN106667583A discloses a seven-degree-of-freedom operating hand of a minimally invasive surgical robot, comprising a base, a turntable arranged on the base and rotating around the z-axis, a connecting rod connected to the turntable and capable of rotating around the x-axis, a No. 1 self-rotating connecting rod connected to the connecting rod and capable of rotating around the x-axis, a No. 2 self-rotating connecting rod connected to the No. 1 self-rotating connecting rod and capable of rotating around the x-axis, and a clamping mechanism connected to the No. 2 self-rotating connecting rod, wherein the clamping mechanism comprises a thumb component and an index finger component that rotate relative to each other. Although the operating hand can realize seven-degree-of-freedom operation, it has a complex structure and a long force transmission path, which makes it difficult to perform precise surgical operations.

[0003] Therefore, those skilled in the art are committed to developing a surgical robot main hand tool with a simple structure and easy operation. Summary of the invention

[0004] In view of the above-mentioned defects in the prior art, the technical problem to be solved by the present invention is to provide a surgical robot main hand tool with a simple structure and easy operation.

[0005] To achieve the above objectives, the present invention provides a surgical robot main hand tool, including a shell that can be connected to the main hand; a motor is arranged in the shell; the motor shaft of the motor is fixedly connected to the first control block; and an encoder is fixed at the bottom of the motor.

[0006] For the reliability of the system and to facilitate the installation of the motor, the housing includes a cylindrical motor installation portion; the motor is arranged in the motor installation portion through a positioning structure.

[0007] In order to fix the motor on the motor mounting part, use less space for accurate positioning and fixing, and have high flexibility, the positioning structure includes an annular connecting seat fixed to the end of the motor away from the encoder; a first clamping bearing is arranged between the connecting seat and the motor mounting part;

[0008] The upper end of the outer ring of the first clamping bearing is positioned by a limit seat fixed to the upper end of the motor mounting portion; the lower end of the outer ring of the first clamping bearing abuts against the upper end surface of the first positioning step correspondingly arranged on the upper part of the motor mounting portion;

[0009] A second protruding positioning step is provided on the upper part of the connecting seat; the lower end of the second positioning step abuts against the upper end of the inner ring of the first clamping bearing; a positioning washer sleeved on the connecting seat is provided between the lower end of the inner ring of the first clamping bearing and the upper end surface of the motor.

[0010] In order to control the movement of the second control block through the motor body, the motor body of the motor is fixedly connected to the second control block through the connecting seat.

[0011] In order to realize the control direction of the control block and the linkage function between the first control block and the second control block, a linkage component is arranged between the first control block and the second control block.

[0012] In order to realize the linkage between the first control block and the second control block, the linkage assembly includes a first hinged member and a second hinged member whose one ends are hinged to each other through a first hinge shaft;

[0013] The first articulated shaft is arranged to float;

[0014] The other end of the first hinge is connected to the second control block, and one end of the second hinge is connected to the first control block.

[0015] In order to increase the flexibility of the linkage between the first control block and the second control block, the other end of the first hinge is hinged to the second control block through a second hinge shaft; the other end of the second hinge is hinged to the first control block through a third hinge shaft.

[0016] In order to limit the movement of the first hinge shaft within a certain activity space, the first hinge shaft is arranged in a guide mechanism; the guide mechanism includes a first guide block and a second guide block fixedly connected to the limit seat; a guide groove is formed between the first guide block and the second guide block; a rolling bearing is sleeved on the first hinge shaft, and the rolling bearing is rollingly arranged in the guide groove.

[0017] In order to support the palm and reduce fatigue, an end cover is fixedly arranged on the limiting seat, and a palm rest is arranged on the end cover.

[0018] In order to install the palm rest on the end cover, the outer side wall of the end cover has a first concave hole, and the palm rest has a through hole arranged opposite to the first concave hole; a spring and a first limiting column extending into the through hole are arranged in the first concave hole, and an anti-drop structure for limiting the first limiting column from falling off is arranged in the end cover;

[0019] The anti-slip structure includes a second recessed hole arranged at the end of the end cover and intersecting with the first recessed hole, and a second limiting column passing through the second recessed hole; the first limiting column has a limiting groove or a limiting hole, and the second limiting column extends into the limiting groove or the limiting hole.

[0020] By setting different length ratios between the first hinge and the second hinge of the linkage assembly, the stroke ratio between the first control block and the second control block and the required shifting force ratio can be achieved.

[0021] The beneficial effects of the present invention are as follows: the main hand tool of the surgical robot of the present invention has a simple structure, high flexibility, high precision and easy operation; a palm rest is arranged on the end cover, and its shape matches the palm, so the doctor is not easily fatigued during long-term operation, and the surgical precision is effectively improved; the thumb has a large force, controls the second control block, has a small stroke, and is used to drive the motor body to rotate; the index finger has a small force, controls the first control block, has a large stroke, and is more flexible, and is used to drive the motor shaft to rotate, which can fully meet the different requirements of the force and stroke of the two fingers. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the connection between the main hand tool and the main hand of a surgical robot in one specific embodiment of the present invention.

[0023] Figure 2 yes Figure 1 Schematic diagram of the partial structure of the main hand tool of the surgical robot.

[0024] Figure 3 yes Figure 2 Schematic diagram of the local structure.

[0025] Figure 4 It is a schematic diagram of the front view structure of the main hand tool of the surgical robot in a specific embodiment of the present invention.

[0026] Figure 5 yes Figure 4 Schematic diagram of the cross-sectional structure of AA.

[0027] Figure 6 yes Figure 5 Schematic diagram of the structure at part I in the figure.

[0028] Figure 7 yes Figure 4 Schematic diagram of the cross-sectional structure of BB.

[0029] Figure 8 yes Figure 7 Schematic diagram of the structure at local II in the middle.

[0030] Fig. 9 yes Figure 5 Schematic diagram of the cross-sectional structure of CC.

[0031] Fig.10 It is a structural schematic diagram of a motor mounting portion according to a specific embodiment of the present invention.

[0032] Fig.11 It is another cross-sectional structural schematic diagram of the main hand tool of the surgical robot according to a specific embodiment of the present invention.

[0033] Fig.12 It is a structural schematic diagram of a shell according to a specific embodiment of the present invention.

[0034] Fig.13 It is a schematic diagram of the cross-sectional structure of the shell.

[0035] Fig.14 yes Fig.13 Schematic diagram of the enlarged structure at III in the middle.

[0036] Fig.15 It is a structural schematic diagram of an upper cover plate in a specific implementation manner of the present invention.

[0037] Fig.16 yes Fig.15 Schematic diagram of the structure viewed from above.

[0038] Fig.17 yes Fig.15 Schematic diagram of the top view structure.

[0039] Fig.18 yes Fig.17 Schematic diagram of EE cross-sectional structure.

[0040] Fig.19 yes Fig.17 Schematic diagram of the FF cross-sectional rotation structure.

[0041] Fig. 20 yes Fig.17 Schematic diagram of the GG cross-sectional structure.

[0042] Fig.21 yes Fig. 20 Schematic diagram of the HH cross-sectional structure.

[0043] Fig. 22 It is a structural schematic diagram of a self-clamping nut in a specific implementation manner of the present invention. DETAILED DESCRIPTION

[0044] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0045] like Figures 1 to 11 As shown, an embodiment of the present invention discloses a surgical robot master hand tool, including a housing 100 that can be connected to a master hand, a motor 3 is arranged in the housing 100, a motor shaft 4 of the motor 3 is fixedly connected to a first control block 7, and an encoder 5 is fixed to the lower part of the motor 3. The housing 100 includes a cylindrical motor mounting portion 102, and the motor 3 is arranged in the motor mounting portion 102 through a positioning structure.

[0046] The encoder 5 is connected to the control center of the surgical robot. After the encoder reads the torque, speed and angle of the motor body 2 and the motor shaft 4 of the motor, the encoder transmits the above data to the control center through the connecting line set in the housing 100. The control center controls the synchronous movement of the instruments of the surgical robot. The motor shaft 4 of the motor 3 is inserted into the motor body 2, and the motor shaft 4 can rotate along its own central axis in the motor body 2; the motor body 2 is only axially positioned and can rotate around the central axis of the motor shaft 4.

[0047] The positioning structure includes an annular connecting seat 12 fixed to the end of the motor 3 away from the encoder 5, a first clamping bearing 6 is arranged between the connecting seat 12 and the motor mounting portion 102, the upper end of the outer ring of the first clamping bearing 6 is positioned by a limit seat 14 fixed to the upper end of the motor mounting portion 102, the lower end of the outer ring of the first clamping bearing 6 abuts against the upper end surface of the first positioning step 11 correspondingly arranged on the upper part of the motor mounting portion 102, the upper part of the connecting seat 12 is provided with a convex second positioning step 13, the lower end of the second positioning step 13 abuts against the upper end of the inner ring of the first clamping bearing 6, and a positioning washer 15 sleeved on the connecting seat 12 is arranged between the lower end of the inner ring of the first clamping bearing 6 and the upper end surface of the motor 3. The connecting seat 12 is fixedly connected to the motor body 2 of the motor 3.

[0048] The upper and lower ends of the first clamping bearing 6 are tightly fixed by the connecting seat 12, the limit seat 14 and the motor mounting part 102, thereby increasing the reliability of the entire system; at the same time, less space is used to achieve precise positioning and fixation with high flexibility; and timely feedback of force can be achieved to ensure the stability of the system.

[0049] The linkage structure includes a first control block 7 and a second control block 8, and a linkage component is provided between the first control block 7 and the second control block 8. In this embodiment, the motor shaft 4 of the motor 3 is fixedly connected to the first control block 7. In this embodiment, the motor body 2 of the motor 3 is fixedly connected to the second control block 8 through the connecting seat 12.

[0050] The first control block 7 is an index finger component, and the second control block 8 is a thumb component. The thumb has a strong force, controls the second control block, has a small stroke, and is used to rotate the motor body 2; the index finger has a weak force, controls the first control block, has a large stroke, is more flexible, and is used to rotate the motor shaft, which can fully meet the different requirements of the force and stroke of the two fingers. In other embodiments, the first control block 7 can also be a thumb component, and the second control block 8 can be an index finger component.

[0051] The first control block 7 has a first finger ring 16 on the outside, and the second control block 8 has a second finger ring 17 on the outside. The first control block 7 and the second control block 8 are connecting rods respectively. The central axis of the first finger ring 16 has a certain inclination angle relative to the motor mounting portion 102. When the palm acts on the palm rest 10, the direction pointed by the first control block is the direction of the central axis of the first finger ring 16; the central axis of the second finger ring 17 has a certain inclination angle relative to the motor mounting portion 102. When the palm acts on the palm rest 10, the direction pointed by the second control block 8 is the direction of the central axis of the second finger ring 17, that is, the first finger ring 16 and the second finger ring 17 are the natural angles of the fingers, and the hand is not easily fatigued.

[0052] The linkage assembly includes a first hinge 18 and a second hinge 19, one end of which is hinged to each other through a first hinge shaft 20, and the first hinge shaft 20 is arranged in a floating manner. The other end of the first hinge 18 is connected to the second control block 8, and one end of the second hinge 19 is connected to the first control block 7. The floating arrangement means that the first hinge shaft 20 is suspended in the air through the hinge of the first hinge 18 and the second hinge 19, and can move in the guide mechanism.

[0053] The other end of the first hinge 18 is hinged to the second control block 8 via a second hinge shaft 21; the other end of the second hinge 19 is hinged to the first control block 7 via a third hinge shaft 22. The first hinge shaft 20, the second hinge shaft 21 and the third hinge shaft 22 are parallel to each other. The second hinge shaft 21 and the third hinge shaft 22 are both floating.

[0054] In other embodiments, one end of the first hinge 18 is fixedly connected to the second control block 8, and one end of the second hinge 19 is fixedly connected to the first control block 7. In other embodiments, the first hinge 18 is integrally formed with the second control block 8, and the second hinge 19 is integrally formed with the first control block 7.

[0055] The first hinge shaft 20 is arranged in the guide mechanism, which includes a first guide block 23 and a second guide block 24 fixedly connected to the limit seat 14, and a guide groove is formed between the first guide block 23 and the second guide block 24; a rolling bearing 25 is sleeved on the first hinge shaft 20, and the rolling bearing 25 is rolled in the guide groove. The guide groove extends along the radial direction of the motor mounting portion 102. Guide mechanism

[0056] In some embodiments, limit stop edges may be provided at the upper and lower ends of the first hinge shaft 20, respectively, to prevent the rolling bearing 25 from moving axially along the first hinge shaft 20. Limit stop edges are provided on the first hinge shaft 20, the second hinge shaft 21, and the third hinge shaft 22. At this time, when the first hinge 18 and the second control block 8 rotate, the second hinge shaft 21 will not move axially, and when the second hinge 19 and the first control block 7 rotate, the third hinge shaft 22 will not move axially. When the first hinge 18 and the second hinge 19 rotate, the first hinge shaft 20 will not move axially.

[0057] An end cover 9 is fixedly arranged on the limit seat 14, and a slot is provided between the end cover 9 and the limit seat 14, and the first control block 7 and the second control block 8 extend outward from the slot. The slot is arranged circumferentially along the end cover 9, and the first control block 7 can drive the motor shaft 4 to rotate around the central axis when moving in the slot, and the second control block 8 can drive the motor body 2 to rotate around the central axis when moving in the slot.

[0058] The end cover palm rest connection structure comprises an end cover 9 and a palm rest 10. The end cover 9 is provided with the palm rest 10. The palm rest 10 is used to support the palm. The inner side wall of the palm rest 10 is fixedly connected to the outer side wall of the end cover 9.

[0059] In this embodiment, the outer wall of the end cover 9 has a first concave hole 9a, and the palm rest 10 has a through hole 10a arranged opposite to the first concave hole; a spring 26 and a first limiting column 27 extending into the through hole 10a are arranged in the first concave hole 9a, and an anti-drop structure for limiting the drop of the first limiting column 27 is arranged in the end cover 9. Since there is only one through hole 10a on the palm rest, the integrity of the palm rest shape is ensured, and no discomfort is caused to the palm.

[0060] In this embodiment, the anti-drop structure includes a second concave hole arranged at the end of the end cover 9 and intersecting with the first concave hole, and a second limiting column 28 penetrated in the second concave hole. The first limiting column 27 has a limiting groove 29 or a limiting hole, and the second limiting column 28 extends into the limiting groove 29 or the limiting hole. The second limiting column 28 is inserted into the limiting groove 29 or the limiting hole, which can limit the first limiting column 27 from falling outward. The second limiting column 28 is inserted into the limiting groove 29. Under the elastic force of the spring 26, one end of the limiting groove 29 on the first limiting column 27 abuts against the second limiting column 28, which can limit the first limiting column 27 from falling outward.

[0061] like Figures 12 to 22 As shown, the shell 100 includes a main hand mounting portion 101, a cylindrical motor mounting portion 102, an upper cover plate 104, a side shell 105 and a bottom shell 103. The main hand mounting portion 101 and the side shell 105 are made as one piece. After the side shell 105 and the bottom shell 103 are fixedly connected, the upper cover plate 104 is buckled on the side shell 105 and the bottom shell 103.

[0062] The lower end of the motor mounting portion 102 is threadedly connected to the upper cover plate 104. The outer wall of the housing 100 is a smooth surface.

[0063] The motor 3 is arranged in the motor mounting portion 102 through a positioning structure. The main hand mounting portion 101 of the main hand tool of the surgical robot can be connected to the main hand 34 .

[0064] A plurality of positioning holes 31 are provided at the lower end of the motor mounting portion 102. When the motor mounting portion 102 and the upper cover plate 104 are threadedly connected in place, a limit screw 30 is provided to prevent loosening during use. When the limit screw 30 is inserted into the positioning hole 31, the circumferential rotation of the motor mounting portion 102 can be effectively limited, thereby preventing the motor mounting portion 102 from falling off.

[0065] The bottom shell 103 is provided with a first mounting bevel 103b at one end away from the motor mounting portion 102, and a first through hole 103d is provided on the first mounting bevel 103b. The lower part of the side shell 105 is provided with a second mounting bevel 105a which is in contact with the first mounting bevel 103b, and the bottom shell 103 is fixedly connected to the side shell 105 by a first fixing screw 33 passing through the first through hole 103d.

[0066] The bottom shell 103 is provided with a second through hole 103c, and the bottom end of the upper cover plate 104 is provided with a slot 104a, in which a self-locking nut 35 is provided. The self-locking nut 35 includes an embedding portion 35a that can be embedded in the slot 104a, and a nut mounting portion 35b that is integrally and vertically connected to the embedding portion 35a, and the screw hole 35b is provided in the middle of the nut mounting portion 35b. The second fixing screw 32 passes through the second through hole 103c and is connected to the self-locking nut 35. Therefore, the second screw 32 further fixes the bottom shell 102 and the upper cover plate 104. Through the design of the slot 104a and the self-locking nut 35, the housing is reliably fixed and the installation and disassembly of the motor are convenient.

[0067] In the surgical robot main hand tool of the present invention, when the finger operates the first control block 7 to move in the slot, the motor shaft 4 starts to rotate, and the encoder 5 reads the torque, speed, angle and other data of the motor shaft 4, and transmits the above data to the control center through the connecting line set in the shell 100, and the control center controls the synchronous movement of the surgical robot's instruments. At the same time, the first control block 7 drives the movement of the second hinge 19, and the second hinge 19 drives the movement of the first hinge 18 under the action of the guide mechanism, and the first hinge 18 drives the movement of the second control block 8 in the slot, and the second control block 8 further drives the rotation of the motor body 2. After the encoder 5 reads the torque, speed and angle and other data of the motor body 2, it transmits the above data to the control center through the connecting line set in the shell 100, and the control center controls the synchronous movement of the surgical robot's instruments.

[0068] Similarly, when the finger operates the second control block 8 to move in the slot, the motor body 2 starts to rotate, and the encoder 5 reads the torque, speed, angle and other data of the motor body 2, and transmits the above data to the control center through the connection line set in the shell 100, and the control center controls the synchronous movement of the surgical robot. At the same time, the second control block 8 drives the movement of the first hinge 17, and the first hinge 17 drives the movement of the second hinge 18 under the action of the guide mechanism. The movement of the second hinge 18 drives the first control block 7 to move in the slot, and the first control block 7 then drives the rotation of the motor shaft 4. After the encoder 5 reads the torque, speed and angle and other data of the motor shaft 4, it transmits the above data to the control center through the connection line set in the shell 100, and the control center controls the synchronous movement of the surgical robot.

[0069] The main hand mounting part 101 and the side shell 105 are made in one piece, the lower end of the motor mounting part 102 is threadedly connected to the upper cover plate 104, and the limiting screw 30 is inserted into the positioning hole 31 for limiting; the bottom shell 103 and the side shell 105 are fixed by the first fixing screw 33, and the lower end of the upper cover plate 104 is buckled with the upper ends of the bottom shell 103 and the side shell 105. The second fixing screw 32 can also be used to connect the bottom shell 103 and the upper cover plate 104 for reinforcement.

[0070] When the surgical robot is in working state, the motor mounting part 102 is roughly in a vertical state, and the palm rest 10 is located at the top of the motor mounting part 102. The shape of the palm rest 10 matches the palm of the hand, and it is roughly hemispherical. The force of the palm on the palm rest 10 acts on the end cover 9, the end cover acts on the motor mounting part 102, and the motor mounting part 102 acts on the active arm. Due to the support of the palm rest 10, the doctor is not easy to get tired when operating the surgical robot for a long time, which effectively improves the surgical accuracy.

[0071] The main hand tool of the surgical robot of the present invention has a simple structure, high flexibility, high precision and easy operation; a palm rest is arranged on the end cover, and its shape matches the palm, so the doctor is not easily fatigued during long-term operation, and the surgical precision is effectively improved; the thumb has a strong force, controls the second control block, has a small stroke, and is used to drive the motor body to rotate; the index finger has a weak force, controls the first control block, has a large stroke, is more flexible, and is used to drive the motor shaft to rotate, which can fully meet the different requirements of the force and stroke of the two fingers.

[0072] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A surgical robot main hand tool, characterized by: The invention comprises a housing (100) connectable to a master hand; a motor (3) is arranged in the housing (100); a motor shaft (4) of the motor (3) is fixedly connected to a first control block (7); an encoder (5) is fixed at the lower part of the motor (3); The motor body (2) of the motor (3) is fixedly connected to the second control block (8); The motor shaft (4) can rotate along its own central axis in the motor body (2), and the motor body (2) can rotate around the central axis of the motor shaft (4); The first control block (7) has a first finger ring (16) on its outer side, and the second control block (8) has a second finger ring (17) on its outer side; A linkage component is provided between the first control block (7) and the second control block (8); The linkage assembly comprises a first hinged member (18) and a second hinged member (19) whose ends are hinged to each other via a first hinge shaft (20); The other end of the first hinge (18) is connected to the second control block (8), and one end of the second hinge (19) is connected to the first control block (7); The first hinge shaft (20) is arranged to float; The first hinge shaft (20) is arranged in the guide mechanism; The guide mechanism comprises a guide groove, and a rolling bearing (25) is sleeved on the first hinge shaft (20), and the rolling bearing (25) is rollingly arranged in the guide groove.

2. The surgical robot main hand tool according to claim 1, characterized in that: The housing (100) comprises a cylindrical motor mounting portion (102); the motor (3) is arranged in the motor mounting portion (102) via a positioning structure.

3. The surgical robot main hand tool according to claim 2, characterized in that: The positioning structure comprises an annular connecting seat (12) fixed to an end of the motor (3) away from the encoder (5); a first clamping bearing (6) is arranged between the connecting seat (12) and the motor mounting portion (102); The upper end of the outer ring of the first clamping bearing (6) is positioned by a limit seat (14) fixed to the upper end of the motor mounting portion (102); the lower end of the outer ring of the first clamping bearing (6) abuts against the upper end surface of a first positioning step (11) correspondingly arranged on the upper part of the motor mounting portion (102); The upper part of the connecting seat (12) is provided with a second protruding positioning step (13); the lower end of the second positioning step (13) abuts against the upper end of the inner ring of the first clamping bearing (6); and a positioning washer (15) sleeved on the connecting seat (12) is provided between the lower end of the inner ring of the first clamping bearing (6) and the upper end surface of the motor (3).

4. The surgical robot main hand tool according to claim 3, characterized in that: The motor body (2) of the motor (3) is fixedly connected to the second control block (8) via a connecting seat (12).

5. The surgical robot main hand tool according to claim 1, characterized in that: The other end of the first hinged member (18) is hinged to the second control block (8) via a second hinge shaft (21); the other end of the second hinged member (19) is hinged to the first control block (7) via a third hinge shaft (22); the second hinge shaft (21) and the third hinge shaft (22) are both floating arrangements.

6. The surgical robot main hand tool according to claim 3, characterized in that: The guide mechanism comprises a first guide block (23) and a second guide block (24) which are fixedly connected to the limiting seat (14); a guide groove is formed between the first guide block (23) and the second guide block (24).

7. The surgical robot main hand tool according to claim 3, characterized in that: An end cover (9) is fixedly arranged on the limiting seat (14), and a palm rest (10) is arranged on the end cover (9).

8. The surgical robot main hand tool according to claim 7, characterized in that: The outer wall of the end cover (9) has a first concave hole (9a), and the palm rest (10) has a through hole (10a) arranged opposite to the first concave hole (9a); a spring (26) and a first limiting column (27) extending into the through hole (10a) are arranged in the first concave hole (9a), and an anti-falling structure for limiting the falling of the first limiting column (27) is arranged in the end cover (9); The anti-slip structure comprises a second recessed hole arranged at the end of the end cover (9) and intersecting with the first recessed hole (9a), and a second limiting column (28) penetrating into the second recessed hole; the first limiting column (27) has a limiting groove (29) or a limiting hole, and the second limiting column (28) extends into the limiting groove (29) or the limiting hole.

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