Three degree of freedom surgical instrument

Abstract

The application discloses a three-degree-of-freedom surgical instrument, which comprises a main body, an execution mechanism, a driving mechanism, two groups of driving wires and a compensation mechanism. The execution mechanism is installed on the main body and comprises a first joint part and a second joint part. The first end of the first joint part is rotatably installed on the main body around an axis in a first direction. The first end of the second joint part is rotatably installed on the second end of the first joint part around an axis in a second direction perpendicular to the first direction. The second end of the second joint part is configured to be installed with an execution part suitable for surgery. The driving mechanism is installed on the main body. The two groups of driving wires are configured to drive the first joint part to deflect relative to the axis of the main body and drive the second joint part to deflect relative to the axis of the first joint part under the driving of the driving mechanism. The compensation mechanism is installed on the main body and is configured to compensate for the slack or excessive tension of the driving wire connected with the second joint part when the first joint part deflects, so as to maintain the coaxiality of the second joint part and the first joint part.

Description

TECHNICAL FIELD

[0001] At least one embodiment of the present disclosure relates to the technical field of surgical instruments, in particular to a three-degree-of-freedom surgical instrument. BACKGROUND

[0002] In a robot-assisted minimally invasive surgery process, a surgical instrument in the system acts as an end effector in accordance with a master-slave control mode of the system, and the action of a master hand of a doctor is directly applied to a lesion site of a patient. Currently, a surgical instrument for minimally invasive surgery generally adopts a wire transmission transmission mode.

[0003] A wire transmission surgical instrument is a surgical instrument that uses a steel wire as a traction wire to drive a surgical execution terminal such as an electric hook or operating forceps to perform a surgical operation. In the wire transmission surgical instrument, the traction wire drives the joint of the end to swing, and the joint drives the surgical execution terminal to reach the required surgical position. However, when the wire transmission drives the joint to swing and is not linear transmission, the traction wire will be in a wire relaxation or transition tension state, which leads to a decrease in the control accuracy of the surgical instrument and affects the accuracy of the surgical instrument. SUMMARY

[0004] In view of the existing technical problems, the present disclosure provides a three-degree-of-freedom surgical instrument to at least partially solve the above technical problems, reduce the error caused by the relaxation or transition tension of the driving wire, and improve the accuracy of the surgical instrument.

[0005] An embodiment of the present disclosure provides a three-degree-of-freedom surgical instrument, which comprises a main body part; an execution mechanism installed on the main body part and comprising a first joint part, a first end of the first joint part being rotatably installed on the main body part about an axis in a first direction; and a second joint part, a first end of the second joint part being rotatably installed on a second end of the first joint part about an axis in a second direction perpendicular to the first direction, a second end of the second joint part being configured to install an execution part suitable for surgery; a driving mechanism installed on the main body part; two groups of driving wires configured to drive the first joint part to deflect relative to the axis of the main body part and drive the second joint part to deflect relative to the axis of the first joint part under the driving of the driving mechanism; and a compensation mechanism installed on the main body part and configured to compensate for the relaxation or transition tension of the driving wire connected with the second joint part when the first joint part deflects, so as to maintain the second joint part coaxial with the first joint part.

[0006] According to an embodiment of the present disclosure, the compensation mechanism is configured to tension the second driving wire connected to the second joint part in the two groups of driving wires to compensate for slack of the second driving wire during the first joint part deviating from the axis of the main body part; and slacken the second driving wire to compensate for over-tensioning of the second driving wire during the first joint part rotating close to the axis of the main body part.

[0007] According to an embodiment of the present disclosure, the first joint part and the second joint part each include a tube body, a connecting ear mounted on at least one end of the tube body and configured to allow the first joint part and the second joint part to rotate, and a ring part arranged in the inner cavity of the tube body, the ring part having driving holes for allowing the driving wire to pass through at radially opposite ends in the first direction and the second direction; wherein the first end of the tube body of the first joint part has the connecting ear arranged at radially opposite ends in the first direction, and the second end of the first joint part and the first end of the second joint part have the connecting ear arranged at radially opposite ends in the second direction; preferably, the tube body has a clearance slot arranged on both sides of the connecting ear to allow the first joint part to rotate around the axis in the first direction and the second joint part to rotate around the axis in the second direction.

[0008] According to an embodiment of the present disclosure, the compensation mechanism includes two groups of compensation assemblies, and any one of the two groups of compensation assemblies includes a second wire guide assembly mounted on the main body part and configured to wind and conduct the second driving wire, an adjusting assembly slidably mounted on the second wire guide assembly and configured to tighten or release the second driving wire, and a compensation driving assembly mounted on the main body part and configured to drive the adjusting assembly to slide during the first driving wire in the two groups of driving wires driving the first joint part to rotate; preferably, the adjusting assembly includes a sliding frame slidably mounted on the second wire guide assembly, and a rotating wheel rotatably mounted on the sliding frame and configured to wind and conduct the second driving wire.

[0009] According to an embodiment of the present disclosure, the driving mechanism comprises two deflection driving mechanisms configured to drive the two groups of driving wires respectively, either of the two deflection driving mechanisms comprises a deflection driving assembly mounted on the main body portion, a rotating shaft extending in a third direction perpendicular to the first direction and the second direction and configured to rotate about an axis of the third direction under the driving of the deflection driving assembly, and two driving cams mounted on the rotating shaft, two driving wires in each group of driving wires are reversely wound on the two driving cams respectively, and the two driving cams are configured to drive one of the driving wires to be reeled in and the other driving wire to be unreeled under the driving of the rotating shaft, so that the first joint portion and the second joint portion rotate; preferably, the two deflection driving mechanisms comprise a first deflection driving mechanism configured to drive the two first driving wires and a second deflection driving mechanism configured to drive the two second driving wires.

[0010] According to an embodiment of the present disclosure, the compensation driving assembly comprises a transmission shaft rotatably mounted on the main body portion in the third direction, two adjusting cams mounted on the transmission shaft and configured to drive the adjusting assembly to slide to press or release the second driving wire, and a transmission assembly configured to drive the transmission shaft to rotate in the process that the first deflection driving mechanism drives the first driving wire; preferably, the transmission assembly comprises a first transmission wheel mounted on the rotating shaft of the first deflection driving mechanism and configured to rotate with the rotating shaft, a second transmission wheel mounted on the transmission shaft, and a transmission wire wound between the first transmission wheel and the second transmission wheel and configured to drive the transmission shaft to rotate under the driving of the rotating shaft of the first deflection driving mechanism, so that the two adjusting cams drive the adjusting assembly to slide to press or release the second driving wire.

[0011] According to an embodiment of the present disclosure, the deflection driving mechanism comprises a connecting disc coaxially connected to the rotating shaft and mounted on the rotating shaft, and two protrusions mounted on the same radial direction of the connecting disc to indicate that the actuating mechanism is located at the initial position on the axis of the main body portion when the two protrusions rotate to the preset position.

[0012] According to an embodiment of the present disclosure, the main body part comprises a base and a connecting pipe, a first end of the connecting pipe is rotatably mounted on the base and extends in the third direction, the executing mechanism is mounted on a second end of the connecting pipe, a rotary driving mechanism for driving the connecting pipe to rotate is arranged on the base, the rotary driving mechanism comprises a rotary driving assembly mounted on the base, a driving wheel rotatably mounted on the base and configured to rotate under the driving of the rotary driving assembly, a driven wheel rotatably mounted on the base and connected with the first end of the connecting pipe, and a rotating wire wound on the driving wheel and the driven wheel and configured to drive the driven wheel to rotate under the driving of the driving wheel, so that the connecting pipe rotates around an axis in the third direction to adjust the pose of the executing mechanism.

[0013] According to an embodiment of the present disclosure, two first wire guiding assemblies are further arranged on the main body part and configured to respectively wind and conduct the first driving wire, any one of the first wire guiding assembly and the second wire guiding assembly comprises a support frame mounted on the main body part, a wire guiding wheel rotatably mounted on the support frame and configured to receive the driving wire conducted by the driving cam, a support arm mounted on the support frame and extending towards the first end of the connecting pipe, and a wire guiding shaft mounted on the support arm, the wire guiding shaft is parallel to the third direction with the straight line where the driving hole is located, so as to receive the driving wire conducted by the wire guiding wheel and conduct the driving wire in the third direction.

[0014] According to an embodiment of the present disclosure, the first wire guiding assembly and the second wire guiding assembly further comprise a bracket slidably mounted on the support frame, a tensioning wheel rotatably mounted on the bracket to conduct the driving wire, and an adjusting member mounted on the support frame and abutting against the bracket, configured to drive the bracket to slide to tension the driving wire wound on the tensioning wheel.

[0015] According to the three-degree-of-freedom surgical instrument provided by the present disclosure, under the driving of the driving mechanism, two groups of driving wires respectively drive the first joint part to deflect relative to the axis of the main body part and drive the second joint part to deflect relative to the axis of the first joint part, since the first joint part is rotatably connected with the main body part and the second joint part is rotatably connected with the first joint part, when the first joint part deflects, the driving wire connected with the second joint part will be loosened or over-tensioned, which affects the accuracy of the executing part used for surgery during the operation, the compensation mechanism compensates for the loosening or over-tensioning of the driving wire connected with the second joint part, when the first joint part deflects, the second joint part is maintained coaxial with the first joint part, the influence of the error caused by the loosening or over-tensioning of the driving wire is reduced, thereby improving the accuracy of the surgical instrument. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a perspective view of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure;

[0017] Figure 2 is a perspective view of an actuator of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure;

[0018] Figure 3 is an exploded view of an actuator of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure;

[0019] Figure 4 is a partial cross-sectional view of an actuator of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure, in which a first joint portion is in an initial state coaxial with a connecting tube;

[0020] Figure 5 is another partial cross-sectional view of an actuator of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure, in which a first joint portion is in a deflected state offset from an axis of a connecting tube;

[0021] Figure 6 is a side view of the actuator shown in Figure 4 a partial cross-sectional state;

[0022] Figure 7 is a side view of the actuator shown in Figure 5 a partial cross-sectional state;

[0023] Figure 8 is a perspective view of an actuator, a compensation mechanism, and a driving wire cooperation of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure;

[0024] Figure 9 is a perspective view of a first deflection driving mechanism of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure;

[0025] Figure 10 is a perspective view of a second guide wire assembly of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure;

[0026] Figure 11 is an exploded view of an adjustment assembly of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure; and

[0027] Figure 12 is a partial perspective view of a rotation driving mechanism of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure.

[0028] Reference signs

[0029] 1, main body portion;

[0030] 11, base;

[0031] 12. A connecting tube;

[0032] 2. An actuator;

[0033] 21. A first joint part;

[0034] 211. A first tube body;

[0035] 2111. A let go slot;

[0036] 212. A first connecting lug;

[0037] 213. A first ring part;

[0038] 214. A driving hole;

[0039] 22. A second joint part;

[0040] 221. A second tube body;

[0041] 222. A second connecting lug;

[0042] 223. A second ring part;

[0043] 224. A second driving hole;

[0044] 23. An execution part;

[0045] 3. A deflection driving mechanism;

[0046] 31. A first deflection driving mechanism;

[0047] 32. A second deflection driving mechanism;

[0048] 311. A rotating shaft;

[0049] 312. A driving cam;

[0050] 313. A connecting disc;

[0051] 314. A protrusion;

[0052] 4. A driving wire;

[0053] 41. A first driving wire;

[0054] 42. A second driving wire;

[0055] 5. A compensation mechanism;

[0056] 51. A second guide wire assembly;

[0057] 52. An adjusting assembly;

[0058] 521. A sliding frame;

[0059] 522. A rotating wheel;

[0060] 53. compensating driving assembly;

[0061] 531. transmission shaft;

[0062] 532. adjusting cam;

[0063] 533. conducting assembly;

[0064] 5331. first transmission wheel; 5332. second transmission wheel; 5333. transmission wire;

[0065] 6. rotating driving mechanism;

[0066] 61. driving wheel;

[0067] 62. driven wheel;

[0068] 63. rotating wire;

[0069] 7. first wire conducting assembly;

[0070] 71. supporting frame;

[0071] 72. wire guide wheel;

[0072] 73. supporting arm;

[0073] 74. wire guide shaft;

[0074] 75. supporting bracket;

[0075] 76. tensioning wheel;

[0076] 77. adjusting member. DETAILED DESCRIPTION

[0077] In order to make the objects, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to specific embodiments and drawings.

[0078] However, it should be understood that the description is merely exemplary, and is not intended to limit the scope of the present application. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that one or more embodiments can be practiced without these specific details. In addition, in the following description, descriptions of well-known technology are omitted to avoid unnecessary confusion of the concepts of the present application.

[0079] The terms used herein are merely used to describe specific embodiments, and are not intended to limit the present application. The term "comprising" used herein indicates the presence of a feature, step, operation, but does not exclude the presence or addition of one or more other features.

[0080] In the case of using expressions like "at least one of A, B, and C, etc.", it generally means to include at least one of A, at least one of B, at least one of C, etc. and / or some combination thereof, unless otherwise specifically stated herein. In the case of using expressions like "at least one of A, B, or C, etc.", it generally means to include at least one of A, at least one of B, at least one of C, etc. and / or some combination thereof, unless otherwise specifically stated herein.

[0081] All terms used herein, including technical and scientific terms, have the meanings commonly understood by one of ordinary skill in the art, unless otherwise defined herein. It should be noted that the use of terms such as "first," "second," etc. herein do not generally limit the scope of the application, but are used to distinguish one element from another unless otherwise stated herein.

[0082] The description discloses structural embodiments and methods of the present application. It should be appreciated that this is not intended to limit the present application to particular disclosed embodiments, and the present application can be practiced using other features, elements, methods and embodiments. Similar elements in different embodiments are generally labeled with similar numbers.

[0083] The surgical instrument currently used for minimally invasive surgery generally adopts a wire transmission transmission mode. In the wire transmission surgical instrument, the traction wire drives the joint swing of the end, and the joint drives the surgical execution terminal to reach the required surgical position and perform surgery on the diseased part. However, when the wire transmission drives the joint swing and is not linear transmission, the traction wire will be in the case of wire relaxation or transition tension, which affects the wire transmission force, causes the control accuracy of the surgical instrument to decrease, and affects the accuracy of the surgical instrument.

[0084] Figure 1 is a perspective view of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure.

[0085] Embodiments of the present disclosure propose a three-degree-of-freedom surgical instrument, such as Figure 1As shown, the three-degree-of-freedom surgical instrument includes a body part 1, an actuator 2, a driving mechanism, two groups of driving wires 4 and a compensation mechanism 5. The actuator 2 is installed on the body part 1 and includes a first joint part 21 and a second joint part 22. A first end of the first joint part 21 is rotatably installed on the body part 1 about an axis in a first direction. A first end of the second joint part 22 is rotatably installed on a second end of the first joint part 21 about an axis in a second direction perpendicular to the first direction, and a second end of the second joint part 22 is configured to be installed with an execution part 23 suitable for surgery. The driving mechanism is installed on the body part 1. The two groups of driving wires 4 are configured to drive the first joint part 21 to deflect relative to the axis of the body part 1 and drive the second joint part 22 to deflect relative to the axis of the first joint part 21, respectively, under the driving of the driving mechanism. The compensation mechanism 5 is installed on the body part 1 and is configured to compensate for slack or transitional tension of the driving wire 4 connected with the second joint part 22 when the first joint part 21 deflects, so as to maintain the second joint part 22 coaxial with the first joint part 21.

[0086] According to the embodiment of the present disclosure, the two groups of driving wires 4 drive the first joint part 21 to deflect relative to the axis of the body part 1 and drive the second joint part 22 to deflect relative to the axis of the first joint part 21, respectively, under the driving of the driving mechanism. Since the first joint part 21 is rotatably connected with the body part 1 and the second joint part 22 is rotatably connected with the first joint part 21, the driving wire 4 connected with the second joint part 22 will be slack or be in transitional tension during the process that the first joint part 21 deflects relative to the axis of the body part 1 from a state of horizontal extension to a state of deflection or the first joint part 21 resets relative to the axis of the body part 1 from the state of deflection to the state of horizontal extension, which will affect the accuracy of the execution part 23 for surgery during the operation. The compensation mechanism 5 compensates for the slack or the transitional tension of the driving wire 4 connected with the second joint part 22, maintains the second joint part 22 coaxial with the first joint part 21 when the first joint part 21 deflects, reduces the influence of the error caused by the slack or the transitional tension of the driving wire 4, and thus improves the accuracy of the surgical instrument.

[0087] Figure 2 is a perspective view of an actuator of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure.

[0088] It should be noted that, in the present embodiment, as Figure 1 and Figure 2As shown, two ends of one of the two groups of driving wires 4 are arranged between the driving mechanism and the first joint part 21, and two ends of the other group of driving wires 4 are arranged between the driving mechanism and the second joint part 22. The driving mechanism drives one of the driving wires 4 in one group of driving wires 4 to contract and the other driving wire 4 to expand, so that the first joint part 21 deflects relative to the axis of the main body part 1 and the second joint part 22 deflects relative to the axis of the first joint part 21. Those skilled in the art understand that, in order to achieve sensitive driving of the first joint part 21 and the second joint part 22 by the two groups of driving wires 4, it is necessary to keep both driving wires in each group of driving wires 4 in a normal tension state, that is, each driving wire 4 does not have a natural bending. However, in the process of deflecting the first joint part 21 relative to the axis of the main body part 1 from a state of extending horizontally to a state of being deflected or resetting the first joint part 21 relative to the axis of the main body part 1 from a state of being deflected to a state of extending horizontally, each driving wire connected to the second joint part 22 in the two groups of driving wires 4 will be simultaneously relaxed or simultaneously transitionally tensioned, wherein the transitional tension represents that the tension of the driving wire 4 is greater than the normal tension of the driving wire 4 in the normal tension state; the relaxation represents that the driving wire 4 is relaxed relative to the normal tension state, that is, there is a natural bending.

[0089] Specifically, in the process of deflecting the first joint part 21 away from the axis of the main body part 1, the second driving wire 42 connected to the second joint part 22 in the two groups of driving wires 4 is relaxed, and the compensation mechanism 5 tensions the second driving wire 42 to compensate for the relaxation of the second driving wire 42. In the process of deflecting the first joint part 21 close to the axis of the main body part 1, the second driving wire 42 connected to the second joint part 22 is transitionally tensioned, and the compensation mechanism 5 relaxes the second driving wire 42 to compensate for the transitionally tensioned second driving wire 42. When the first joint part 21 deflects, the relaxation or transitionally tensioned second driving wire 42 is compensated by the compensation mechanism 5, the second joint part 22 is maintained coaxial with the first joint part 21, the influence of the error caused by the relaxation or transitionally tensioned second driving wire 42 is reduced, and thus the precision of the surgical instrument is improved.

[0090] Figure 3 is an exploded view of an actuator of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure.

[0091] In an exemplary embodiment, as Figure 2 and Figure 3As shown, the first joint part 21 and the second joint part 22 each include a tube body, a connecting ear and a ring part. The tube body is a tubular structure, the connecting ear is mounted on at least one end of the tube body and is configured to allow the first joint part 21 to rotate relative to the main body part 1 and the second joint part 22 to rotate relative to the first joint part 21. The ring part is arranged in the inner cavity of the tube body, and the ring part can be integrally connected with the tube body or mounted with the tube body through a detachable connection mode such as clamping or plugging. The ring part is provided with a driving hole for allowing the driving wire 4 to pass through at the radially opposite ends in the first direction and the second direction.

[0092] Specifically, as shown in Figure 2 and Figure 3 , specifically, the first joint part 21 includes a first tube body 211, a first connecting ear 212 and a first ring part 213, the first end of the first tube body 211 of the first joint part 21 is provided with a first connecting ear 212 at the radially opposite ends in the first direction, respectively, and the two first connecting ears 212 are rotatably connected with the main body part 1 through a connecting shaft to allow the first joint part 21 to rotate around the axis of the first connecting ear 212 in the first direction. The second end of the first tube body 211 of the first joint part 21 is provided with a first connecting ear 212 at the radially opposite ends in the second direction, respectively, and the first ring part 213 is located in the inner cavity of the first tube body 211 and perpendicular to the first tube body 211, and the first ring part 213 is provided with a first driving hole 214 for allowing the driving wire 4 to pass through at the radially opposite ends in the first direction and the second direction. The second joint part 22 includes a second tube body 221, a second connecting ear 222 and a second ring part 223, the first end of the second tube body 221 of the second joint part 22 is provided with a second connecting ear 222 at the radially opposite ends in the second direction, respectively, and the second connecting ear 222 and the first connecting ear 212 at the second end of the first joint part 21 are rotatably connected through a connecting shaft to allow the second joint part 22 to rotate around the axis of the second connecting ear 222 in the second direction, and the second ring part 223 is arranged in the inner cavity of the second tube body 221 and perpendicular to the second tube body 221, and the second ring part 223 is provided with a second driving hole 224 for allowing the driving wire 4 to pass through at the radially opposite ends in the first direction and the second direction. The tube body includes the above-mentioned first tube body 211 and second tube body 221, the connecting ear includes the above-mentioned first connecting ear 212 and second connecting ear 222, and the ring part includes the above-mentioned first ring part 213 and second ring part 223. The execution part 23 suitable for surgery is mounted on the second end of the second joint part 22, and the execution part 23 can be an electric hook, an ultrasonic knife, a surgical forceps, a camera or other surgical terminal, which is not limited here.

[0093] In an exemplary embodiment, as Figure 1 and Figure 3As shown, the main body part 1 comprises a base 11 and a connecting tube 12, the first end of the connecting tube 12 is mounted on the base 11 and extends in a third direction perpendicular to both the first direction and the second direction, the second end of the connecting tube 12 is provided with a driving hole for allowing the driving wire 4 to pass through at both ends in the first direction and the second direction respectively. The first connecting lug 212 of the first end of the first joint part 21 is rotationally connected to the second end of the connecting tube 12.

[0094] Further, as shown in Figure 1 , Figure 2 and Figure 3 , the two groups of driving wires 4 comprise two first driving wires 41 and two second driving wires 42. The ends of the two first driving wires 41 are respectively mounted in the first driving holes 214 at the radially opposite ends of the first ring part 213 of the first joint part 21 in the second direction. The ends of the two second driving wires 42 are respectively passed through the first driving holes 214 at the radially opposite ends of the first ring part 213 of the first joint part 21 in the first direction and mounted in the second driving holes 224 at the radially opposite ends of the second ring part 223 of the second joint part 22 in the second direction. The driving mechanism drives one of the two first driving wires 41 to be reeled in, and the other first driving wire 41 to be unreeled, both the two first driving wires 41 are in normal tension state, so that the first joint part 21 is flexibly deflected around the axis in the first direction.

[0095] Figure 4 is a sectional view of an actuator of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure, wherein the first joint part is in an initial state coaxial with the connecting tube. Figure 5 is another sectional view of an actuator of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure, wherein the first joint part is in a deflected state deviating from the axis of the connecting tube. Figure 6 is Figure 4 a side view of the actuator in a partially sectioned state. Figure 7 is Figure 5 a side view of the actuator in a partially sectioned state.

[0096] According to an embodiment of the present disclosure, as shown in Figure 4 and Figure 6 , there is a distance difference between the first connecting lug 212 of the first end of the first joint part 21 and the first driving hole 214 on the first ring part 213 of the first joint part 21 in the axial direction. As shown in Figure 5 and 7 , during the process of the first joint part 21 deviating from the axis of the connecting tube 12 of the main body part 1, the distance between the first driving hole 214 of the first joint part 21 and the first connecting lug 212 between the first joint part 21 and the connecting tube 12 decreases. As shown in Figure 6 and Figure 7As shown, in the process of the first joint part 21 deviating from the axis of the main body part 1, since the second joint part 22 rotates with the first joint part 21, the distance between the second driving hole 214 of the second joint part 22 and the driving hole of the second end of the connecting pipe 12 is constantly reduced, and Figure 5 in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than Figure 4 in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than

[0097] in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than Figure 2 in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than Figure 3 in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than

[0098] in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than Figure 8 in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than

[0099] in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than Figure 8 in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than

[0100] in the process of the first joint part 21 deviating from the axis of the main body part 1, the distance between the driving hole of the connecting pipe 12 and the first driving hole 214 of the first joint part 21 is less than Figure 9is a perspective view of a first deflection driving mechanism of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure. Figure 10 is a perspective view of a second wire guide assembly of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure. Figure 11 is a perspective view of an adjustment assembly of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure.

[0101] In an exemplary embodiment, as shown in Figure 8 , Figure 10 and Figure 11 , the adjustment assembly 52 comprises a sliding frame 521 and a rotating wheel 522. The sliding frame 521 is slidably mounted on the second wire guide assembly 51. The rotating wheel 522 is rotatably mounted on the sliding frame 521 and is configured to wind and conduct the second driving wire 42.

[0102] According to an embodiment of the present disclosure, the second driving wire 42 is wound on and conducted by the second wire guide assembly 51, and in the process of driving the first joint 21 to rotate by the first driving wire 41, the sliding frame 521 is driven to slide relative to the second wire guide assembly 51 by the driving assembly 53 to compress or release the second driving wire 42, compensate for the slack or excessive tension of the second driving wire 42, maintain the coaxiality of the second joint 22 and the first joint 21, reduce the influence of errors caused by the slack or excessive tension of the driving wire, and thus improve the accuracy of the surgical instrument.

[0103] In an exemplary embodiment, as shown in Figure 8 and Figure 9 , the driving mechanism comprises two deflection driving mechanisms 3 configured to drive two groups of driving wires 4 respectively, and any one of the two deflection driving mechanisms 3 comprises a deflection driving assembly, a rotating shaft 311 and two driving cams 312. The deflection driving assembly is mounted on the main body 1, and the deflection driving assembly (not shown in the figure) can be a servo motor. The rotating shaft 311 extends in the third direction and is configured to rotate around the axis in the third direction under the drive of the deflection driving assembly. The two driving cams 312 are mounted on the rotating shaft 311, and the two driving wires 4 in each group of driving wires 4 are reversely wound on the two driving cams 312 respectively, and the two driving cams 312 are configured to drive one of the driving wires 4 to wind under the drive of the rotating shaft 311, while driving the other driving wire 4 to unwind, so that the first joint 21 and the second joint 22 rotate.

[0104] Specifically, as shown in Figure 8 and Figure 9As shown, the two deflection driving mechanisms 3 include a first deflection driving mechanism 31 and a second deflection driving mechanism 32. The first deflection driving mechanism 31 is configured to drive the two first driving wires 41, and the second deflection driving mechanism 32 is configured to drive the two second driving wires 42. The two first driving wires 41 are reversely wound on the two driving cams 312 of the first deflection mechanism respectively; and the two second driving wires 42 are reversely wound on the two driving cams 312 of the second deflection mechanism respectively.

[0105] According to the embodiment of the present disclosure, in use, the deflection driving assembly of the first deflection driving mechanism 31 drives the rotation shaft 311 to rotate around the axis in the third direction, and the two driving cams 312 drive one of the first driving wires 41 to be wound and the other first driving wire 41 to be unwound, so that the first joint part 21 is deflected around the axis in the first direction towards the direction deviating from the axis of the connecting tube 12 and the direction close to the first driving wire 41 in the wound state. Similarly, the second deflection driving mechanism 32 drives one of the second driving wires 42 to be wound and the other second driving wire 42 to be unwound, so that the second joint part 22 is deflected around the axis in the second direction towards the direction deviating from the axis of the first joint part 21 and the direction close to the second driving wire 42 in the wound state.

[0106] In an exemplary embodiment, as shown in Figure 8 and Figure 9 The base of the base 11 is rectangular or rounded rectangular. The deflection driving mechanism 3 includes a connecting disc 313 and two lugs 314. The connecting disc 313 is mounted on the rotation shaft 311 and coaxially connected with the rotation shaft 311. The two lugs 314 are mounted on the same radial direction of the connecting disc 313, so as to indicate that the actuating mechanism 2 is located at the initial position on the axis of the main body part 1 when the two lugs 314 are rotated to the preset position. In this embodiment, when the same straight line where the two lugs 314 are located is parallel to the side of the base 11, it indicates that the two lugs 314 are rotated to the preset position, and the first joint part 21 and the second joint part 22 of the actuating mechanism 2 are located at the initial position on the axis of the main body part 1 in the third direction, so as to be directly observed and reset to the initial position before or after the surgical operation.

[0107] In an exemplary embodiment, as shown in Figure 8 and Figure 10As shown, the three-degree-of-freedom surgical instrument further comprises two first guide wire assemblies 7, each of which is mounted on the base 11 and configured to wind and conduct the first driving wire 41. Either of the first guide wire assembly 7 and the second guide wire assembly 51 comprises a support frame 71, a guide wire wheel 72, a support arm 73, and a guide wire shaft 74. The support frame 71 is mounted on the base 11. The support frame 71 extends in the third direction. The guide wire wheel 72 is rotatably mounted on the support frame 71 and configured to receive the driving wire 4 conducted by the driving cam 312. The guide wire wheel 72 is provided in plurality, which are distributed along the length direction of the support frame 71, and the driving wire 4 is wound on the plurality of guide wire wheels 72 in a serpentine manner. The support arm 73 is mounted on the support frame 71 and extends towards the first end of the connecting tube 12. The guide wire shaft 74 is mounted on the support arm 73, and the straight line where the driving hole is located is parallel to the third direction, so as to receive the driving wire conducted by the guide wire wheel 72 and conduct it in the third direction.

[0108] In an exemplary embodiment, as shown in Figure 10 The guide wire shaft 74 is rotatably mounted on the support arm 73, so as to reduce the frictional resistance of the driving wire 4 during transmission, reduce the degree of wear of the driving wire 4, and improve the service life of the driving wire.

[0109] According to the embodiment of the present disclosure, the two first guide wire assemblies 7 receive the two first driving wires 41 conducted by the two driving cams 312 of the first deflection driving mechanism 31, respectively. The first driving wire 41 on the driving cam 312 is conducted to the guide wire wheel 72 of the first guide wire assembly 7, and then the first driving wire 41 is conducted to the guide wire shaft 74 of the first guide wire assembly 7, which extends in the third direction and is arranged in the first driving hole 214 at the radially opposite ends of the first ring portion 213 of the first joint portion 21 in the second direction. The two second guide wire assemblies 51 receive the two second driving wires 42 conducted by the two driving cams 312 of the second deflection driving mechanism 32, respectively. The second driving wire 42 is wound and conducted to the guide wire wheel 72 of the second guide wire assembly 51 and the rotating wheel 522 of the compensation mechanism 5, and then the second driving wire 42 is conducted to the guide wire shaft 74 of the second guide wire assembly 51, which extends in the third direction and is arranged in the second driving hole 224 at the radially opposite ends of the second ring portion 223 of the second joint portion 22 in the first direction. When the first deflection mechanism and the second deflection mechanism drive the first driving wire 41 and the second driving wire 42, respectively, the first joint portion 21 deflects relative to the axis of the main body portion 1 about the axis in the first direction, and the second joint portion 22 deflects relative to the axis of the first joint portion 21 about the axis in the second direction.

[0110] In an exemplary embodiment, as shown in Figure 10 and Figure 11As shown, the first guide wire assembly 7 and the second guide wire assembly 51 further include a bracket 75, a tensioning wheel 76 and an adjusting member 77. The bracket 75 is slidably mounted on the support frame 71. The tensioning wheel 76 is rotatably mounted on the bracket 75 to conduct the drive wire 4. The adjusting member 77 (not shown in the figure) is mounted on the support frame 71. The adjusting member 77 can be a screw rod which penetrates through the support frame 71 and is threadedly engaged with the support frame 71. The end of the screw rod is abutted against the bracket 75 and is configured to drive the bracket 75 to slide so as to tension the drive wire 4 wound on the tensioning wheel 76.

[0111] According to the embodiment of the present disclosure, before the drive wire 4 is installed, the screw rod is rotated to drive the bracket 75 to slide relative to the support frame 71 so as to tension the drive wire 4. After the installation of the drive wire 4 is completed, the initial state adjustment is performed to make the drive wire 4 be in a normal tensioning degree.

[0112] In an exemplary embodiment, as shown in Figure 8 and Figure 10 The compensation drive assembly 53 includes a transmission shaft 531, two adjusting cams 532 and a transmission assembly 533. The transmission shaft 531 is rotatably mounted on the main body portion 1 in the third direction. The two adjusting cams 532 are mounted on the transmission shaft 531 and rotate with the transmission shaft 531 and are configured to drive the adjusting assembly 52 to slide so as to press or release the second drive wire 42. The transmission assembly 533 is configured to drive the transmission shaft 531 to rotate in the process that the first deflection drive mechanism 31 drives the first drive wire 41.

[0113] Specifically, as shown in Figure 8 and Figure 10 The transmission assembly 533 includes a first transmission wheel 5331, a second transmission wheel 5332 and a transmission wire 5333. The first transmission wheel 5331 is mounted on the rotating shaft 311 of the first deflection drive mechanism 31 and rotates with the rotating shaft 311. The second transmission wheel 5332 is mounted on the transmission shaft 531. The transmission wire 5333 is wound between the first transmission wheel 5331 and the second transmission wheel 5332 and is configured to be driven to rotate the transmission shaft 531 under the drive of the rotating shaft 311 of the first deflection drive mechanism 31, so that the two adjusting cams 532 drive the adjusting assembly 52 to slide to press or release the second drive wire 42.

[0114] According to the embodiment of the present disclosure, in the process that the first driving wire 41 drives the first joint part 21 to rotate, the deflection driving assembly of the first deflection driving mechanism 31 drives the rotation shaft 311 to rotate, and the first transmission wheel 5331 rotates with the transmission shaft 531, so that the second transmission wheel 5332 is driven to rotate by the transmission wire 5333, the transmission shaft 531 is driven to rotate, and the two adjusting cams 532 are driven to rotate, so that the sliding frame 521 is driven to slide relative to the second wire guide assembly 51, the rotating wheel 522 is pressed against or released from the second driving wire 42, the relaxation or excessive tension of the second driving wire 42 is compensated, the coaxiality of the second joint part 22 and the first joint part 21 is maintained, the influence of the error caused by the relaxation or excessive tension of the driving wire is reduced, and the accuracy of the surgical instrument is improved.

[0115] In an exemplary embodiment, as shown in Figure 8 and Figure 10 The adjusting cam 532 includes a cylindrical part and a protruding part, the protruding part is connected to the circumference of the cylindrical part and extends outward, and the protruding part is integrally formed with the cylindrical part and smoothly transitions.

[0116] It should be noted that the relaxation amount of the second driving wire 42 caused by the coupling of the first joint part 21 and the second joint part 22 is analyzed, and the outer profile of the adjusting cam 532 is calculated. The change of the wire relaxation length is fitted with the rotation angle curve of the adjusting cam 532, is mapped on the radius of the adjusting cam 532, and determines the shape of the adjusting cam 532.

[0117] According to the embodiment of the present disclosure, in the process that the first deflection driving mechanism 31 drives the first driving wire 41 to make the first joint part 21 deviate from the axis of the connecting pipe 12, the transmission assembly 533 drives the transmission shaft 531 to rotate, and the two adjusting cams 532 are driven to rotate, the contact parts of the two adjusting cams 532 and the sliding frames 521 on the two second wire guide assemblies 51 are both rotated from the cylindrical part to the protruding part, so that the protruding part drives the sliding frames 521 to slide relative to the second wire guide assemblies 51 to press the second driving wire 42 to be tensioned and compensate for the relaxation of the second driving wire 42. In the process that the first deflection driving mechanism 31 drives the first driving wire 41 to make the first joint part 21 close to the axis of the main body part 1, the transmission assembly 533 drives the transmission shaft 531 to rotate in the opposite direction, and the two adjusting cams 532 are driven to rotate in the opposite direction, the contact parts of the two adjusting cams 532 and the sliding frames 521 on the two second wire guide assemblies 51 are both rotated from the protruding part to the cylindrical part, and since the second driving wire 42 is in a tensioned state, in the process that the contact parts of the adjusting cams 532 and the sliding frames 521 are rotated from the protruding part to the cylindrical part, the sliding frames 521 slide to relax the second driving wire 42, to compensate for the excessive tension of the second driving wire 42, reduce the influence of the error caused by the relaxation or excessive tension of the second driving wire 42, and improve the accuracy of the surgical instrument.

[0118] Figure 12 is a perspective view of a rotation driving mechanism of a three-degree-of-freedom surgical instrument according to an embodiment of the present disclosure.

[0119] In an exemplary embodiment, as shown in Figure 1 and Figure 12 the first end of the connecting tube 12 is rotatably mounted on the base 11. The base 11 is provided with a rotation driving mechanism 6 for driving the rotation of the connecting tube 12. The rotation driving mechanism 6 includes a rotation driving assembly, a driving wheel 61, a driven wheel 62 and a rotation wire 63. The rotation driving assembly (not shown in the figure) is mounted on the base 11, and can be a servo motor. The driving wheel 61 is rotatably mounted on the base 11 and is configured to rotate under the driving of the rotation driving assembly. The driven wheel 62 is rotatably mounted on the base 11 and is connected with the first end of the connecting tube 12. The rotation wire 63 is wound between the driving wheel 61 and the driven wheel 62 and is configured to drive the rotation of the driven wheel 62 under the driving of the driving wheel 61, so that the connecting tube 12 rotates around an axis in the third direction to adjust the pose of the execution mechanism 2.

[0120] According to the three-degree-of-freedom surgical instrument provided in the embodiment, under the driving of the driving mechanism, the two groups of driving wires 4 respectively drive the deflection of the first joint part 21 relative to the axis of the main body part 1 and the deflection of the second joint part 22 relative to the axis of the first joint part 21. Since the first joint part 21 is rotatably connected with the main body part 1 and the second joint part 22 is rotatably connected with the first joint part 21, when the first joint part 21 deflects, the driving wire 4 connected with the second joint part 22 will be slackened or transitionally tensioned, which will affect the accuracy of the execution part 23 used for surgery during the surgical operation. The compensation mechanism 5 compensates for the slackening or transitionally tensioning of the driving wire 4 connected with the second joint part 22, so that when the first joint part 21 deflects, the second joint part 22 is maintained coaxial with the first joint part 21, the influence of the error caused by the slackening or transitionally tensioning of the driving wire 4 is reduced, and thus the accuracy of the surgical instrument is improved.

[0121] The above specific embodiments further illustrate the purpose, technical solutions and advantages of the present application. It should be understood that the above description is only specific embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A three-degree-of-freedom surgical instrument, characterized in that, include: Main body (1); An actuator (2) is mounted on the main body (1) and includes: A first joint portion (21), the first end of which is rotatably mounted to the main body portion (1) about an axis in a first direction; and The second joint (22) has its first end rotatably mounted on the second end of the first joint (21) about an axis in a second direction perpendicular to the first direction. The second end of the second joint (22) is configured to mount an execution part (23) suitable for surgery. A drive mechanism is installed on the main body (1); Two sets of drive wires (4) are configured to, under the drive of the drive mechanism, respectively drive the first joint portion (21) to deflect relative to the axis of the main body portion (1) and drive the second joint portion (22) to deflect relative to the axis of the first joint portion (21); and A compensation mechanism (5), mounted on the main body (1), is configured to tension the second drive wire (42) connected to the second joint (22) among the two sets of drive wires (4) to compensate for the slack of the second drive wire (42) during the process of the first joint (21) deviating from the axis of the main body (1); and to slack the second drive wire (42) during the process of the first joint (21) rotating closer to the axis of the main body (1) to compensate for the over-tension of the second drive wire (42) to maintain the second joint (22) and the first joint (21) coaxial. The compensation mechanism (5) includes two sets of compensation components, each of which includes: The second guide wire assembly (51) is mounted on the main body (1) and is configured to wind and conduct the second drive wire (42); An adjustment assembly (52), slidably mounted to the second guidewire assembly (51), is configured to press or release the second drive wire (42); and The compensation drive assembly (53), mounted on the main body (1), is configured to drive the adjustment assembly (52) to slide while the first drive wire (41) of the two sets of drive wires (4) drives the first joint (21) to rotate.

2. The three-degree-of-freedom surgical instrument according to claim 1, characterized in that, Both the first joint portion (21) and the second joint portion (22) include: tube body; A connecting lug, mounted at least one end of the tube, is configured to allow rotation of the first joint (21) and the second joint (22); and A ring portion is provided in the inner cavity of the tube body. The ring portion has driving holes at both ends that are radially opposite in the first direction and the second direction to allow the driving wire (4) to pass through. The first end of the tube of the first joint (21) is provided with the connecting ears at the two radially opposite ends in the first direction, and the second end of the first joint (21) and the first end of the second joint (22) are provided with the connecting ears at the two radially opposite ends in the second direction. The tube body is provided with relief grooves (2111) on both sides of the connecting ear to allow the first joint (21) to rotate about the axis in the first direction and the second joint (22) to rotate about the axis in the second direction.

3. The three-degree-of-freedom surgical instrument according to claim 2, characterized in that, The adjustment component (52) includes: A sliding frame (521) is slidably mounted on the second guidewire assembly (51); and A rotating wheel (522), rotatably mounted on the sliding frame (521), is configured to wind and conduct the second drive wire (42).

4. The three-degree-of-freedom surgical instrument according to claim 3, characterized in that, The drive mechanism includes two deflection drive mechanisms (3), configured to drive two sets of drive wires (4) respectively, and each of the two deflection drive mechanisms (3) includes: A deflection drive assembly is mounted on the main body (1); A rotation axis (311), extending upward in a third direction perpendicular to both the first and second directions, is configured to rotate about the axis in the third direction under the drive of the deflection drive assembly; and Two drive cams (312) are mounted on the rotating shaft (311). Two drive wires (4) in each set of drive wires (4) are wound in opposite directions around the two drive cams (312). The two drive cams (312) are configured to drive one of the drive wires (4) to take in wires and simultaneously drive the other drive wire (4) to release wires under the drive of the rotating shaft (311), so that the first joint (21) and the second joint (22) rotate. The two deflection drive mechanisms (3) include a first deflection drive mechanism (31) and a second deflection drive mechanism (32), wherein the first deflection drive mechanism (31) is configured to drive two first drive wires (41) and the second deflection drive mechanism (32) is configured to drive two second drive wires (42).

5. The three-degree-of-freedom surgical instrument according to claim 4, characterized in that, The compensation drive component (53) includes: The drive shaft (531) is rotatably mounted to the main body (1) in relation to the third direction; Two adjusting cams (532), mounted on and rotating with the drive shaft (531), are configured to drive the adjusting assembly (52) to slide, thereby engaging or disengaging the second drive wire (42); and The transmission component (533) is configured to drive the transmission shaft (531) to rotate during the process of the first deflection drive mechanism (31) driving the first drive wire (41); The conductive component (533) includes: The first transmission wheel (5331) is mounted on the rotating shaft (311) of the first deflection drive mechanism (31) and rotates with the rotating shaft (311); The second transmission wheel (5332) is mounted on the transmission shaft (531); and The drive wire (5333), wound between the first drive wheel (5331) and the second drive wheel (5332), is configured to drive the drive shaft (531) to rotate under the drive of the rotation shaft (311) of the first deflection drive mechanism (31), so that the two adjustment cams (532) drive the adjustment assembly (52) to slide, so as to press against or release the second drive wire (42).

6. The three-degree-of-freedom surgical instrument according to claim 4, characterized in that, The deflection drive mechanism (3) includes: A connecting disc (313) is mounted on the rotating shaft (311) and coaxially connected; and Two protrusions (314) are mounted on the same radial direction of the connecting disk (313) so that when the two protrusions (314) rotate to a preset position, it indicates that the actuator (2) is in the initial position on the axis of the main body (1).

7. The three-degree-of-freedom surgical instrument according to claim 4, characterized in that, The main body (1) includes a base (11) and a connecting pipe (12). The first end of the connecting pipe (12) is rotatably mounted on the base (11) and extends upward from the third end. The actuator (2) is mounted on the second end of the connecting pipe (12). A rotary drive mechanism (6) for driving the connecting pipe (12) to rotate is provided on the base (11). The rotary drive mechanism (6) includes: A rotary drive assembly is mounted on the base (11); The drive wheel (61), rotatably mounted on the base (11), is configured to rotate under the drive of the rotary drive assembly; Driven wheel (62) is rotatably mounted on the base (11) and connected to the first end of the connecting pipe (12); and The rotating wire (63), wound around the driving wheel (61) and the driven wheel (62), is configured to drive the driven wheel (62) to rotate under the drive of the driving wheel (61), so that the connecting tube (12) rotates about the third-direction upward axis to adjust the position of the actuator (2).

8. The three-degree-of-freedom surgical instrument according to claim 7, characterized in that, It also includes two first guide wire assemblies (7) mounted on the main body (1) and configured to respectively wind and conduct the two first drive wires (41), each of the first guide wire assembly (7) and the second guide wire assembly (51) comprising: A support frame (71) is mounted on the main body (1); The guide wheel (72), rotatably mounted on the support frame (71), is configured to receive the drive wire (4) transmitted by the drive cam (312); The support arm (73) is mounted on the support frame (71) and extends toward the first end of the connecting pipe (12); and A guide shaft (74) is mounted on the support arm (73). The straight line between the guide shaft (74) and the drive hole (214) is parallel to the third direction, so as to receive the drive wire (4) transmitted by the guide wheel (72) and transmit it upward in the third direction.

9. The three-degree-of-freedom surgical instrument according to claim 8, characterized in that, The first guidewire assembly (7) and the second guidewire assembly (51) further include: A bracket (75) is slidably mounted on the support frame (71); A tensioning pulley (76), rotatably mounted on the bracket (75), conducts the drive wire (4); and An adjusting member (77), mounted on the support frame (71) and abutting against the bracket (75), is configured to drive the bracket (75) to slide in order to tension the drive wire (4) wound on the tension wheel (76).

Images