Clamp for handling a patella

Abstract

The invention relates to a clamp (1) for handling a patella (91), characterised in that it comprises: - a gripping handle (2); - two jaws (31, 32) that are movable relative to one another so as to modify the spacing between these two jaws, the movable jaws being rigidly connected to the gripping handle, the two jaws each comprising two projecting elements and forming an acute angle at the end thereof, the ends of the projecting elements of the jaws being in one plane, the handling clamp providing a first free space facing the jaws, and providing a second free space facing the jaws for passing tools on a second side of this plane opposite the first; - a device (4) for controlling the spacing between the two jaws (31, 32); and - optical reflectors (5) rigidly connected to the gripping handle.

Description

Description Title of the invention: Ball joint manipulation clamp

[0001] The invention relates to orthopedic surgical operations, and in particular robotic or navigated surgical operations for prosthetic knee surgery with patellar resurfacing.

[0002] The patella articulates with the femoral trochlea, forming the patellofemoral compartment. The patellofemoral compartment is the third joint of the knee, located at the front of the knee. Patellar stability is ensured by two tendons, one superior and one inferior, and the two patellar retinacula. This complex combination of bone structure, muscles, cartilage, and tendons can lead to the development of pathologies, particularly wear and tear such as osteoarthritis.

[0003] The kneecap is subjected to extremely high mechanical stresses; its role is essential in extension and flexion, as well as in movements such as squatting and jumping. The kneecap also acts as a shock absorber. Wear and tear of the patellar cartilage is irreversible, and a misalignment or dislocation will not heal spontaneously. Movements become painful, some even impossible, and walking becomes increasingly difficult.

[0004] Many conditions can lead to premature wear of the knee cartilage, resulting in pain, limping, joint stiffness, and limited activity for the patient. In some cases, the patient may require a total knee replacement. This operation requires very precise cuts and bone preparation. It is a complex procedure that, in some cases, does not provide complete patient satisfaction.

[0005] Implanting a prosthesis requires highly precise prior machining of the bone intended to receive the prosthesis. Certain surgical procedures allow for even greater precision in making the bone cuts. These surgical procedures utilize robots or infrared navigation systems. These methods employ infrared sensors fixed in the femur and tibia for the duration of the surgical procedure, particularly during total knee replacement. These sensors allow the robot / system to R012471 PCT Deposit Text.docx navigation to position cutting tools in real time and precisely to best adapt to the geometry of prosthetic parts.

[0006] In addition to ensuring a perfect fit between the bone and the implant, the surgeon must consider ligament tension as well as patellar mobility. Every error, however minor, can lead to an imperfect result. Therefore, there is a need to minimize the risk of performing a procedure that does not fully satisfy the patient.

[0007] Document WO2023107443 describes a clamp with an annular frame that encircles the ball joint and is equipped with a movable jaw to grip and hold the ball joint in position. Slots are provided in the frame to allow the radial insertion of a saw blade at specific locations. Such a clamp provides only very limited access to the ball joint and allows the use of only one saw blade.

[0008] The invention aims to resolve one or more of these drawbacks. The invention thus relates to a method for controlling a tool-carrying robot, as defined in the attached claims.

[0009] The invention also relates to a clamp for manipulating a ball joint, as defined in the attached claims.

[0010] The invention also relates to variants of the dependent claims. Those skilled in the art will understand that each of the features of the dependent claims and of the description can be combined independently with the features of an independent claim, without thereby constituting an intermediate generalization.

[0011] Other features and advantages of the invention will become clear from the description given below, by way of example and not limitation, with reference to the accompanying drawings, in which:

[0012] [Fig.1] is a perspective view of an example of a manipulation clamp according to a first example of an embodiment of the invention;

[0013] [Fig.2] is a perspective view of the manipulation clamp of figure 1;

[0014] [Fig.3] is an enlarged view at the level of the jaws of the gripper of figure 1; R012471 PCT Deposit Text.docx

[0015] [Fig.4] is a perspective view of the gripper in Figure 1 illustrating an internal jaw piloting mechanism;

[0016] [Fig.5] is an enlarged perspective view of the mechanism in Figure 4;

[0017] [Fig.6] is a front view of an example of an optical reflector system;

[0018] [Fig.7] is a side cross-sectional view of the clamp in Figure 1 carrying the system in Figure 6;

[0019] [Fig.8] shows an enlarged view of the jaws gripping a ball joint;

[0020] [Fig.9] is a perspective view of an example of a manipulation clamp according to a second example of an embodiment of the invention;

[0021] [Fig.10] is a perspective view of the manipulation clamp of figure 9;

[0022] [Fig.11] is a top view of the gripper in Figure 9 at the jaw level;

[0023] [Fig.12] is a top view of the jaws of the clamp in figure 9 gripping a ball joint;

[0024] [Fig. 13] is a top view of an example of a handling clamp according to a third example of an embodiment of the invention;

[0025] [Fig. 14] is a perspective view of the manipulation clamp of figure 13;

[0026] [Fig. 15] is another perspective view of the manipulation clamp of figure 13;

[0027] [Fig.16] is a side view of a kneecap and various tendons;

[0028] [Fig.17] is a side view of the ball joint of figure 16 associated with the clamp of figure 9 in a first manipulation configuration;

[0029] [Fig.18] is a side view of the ball joint of figure 16 associated with the clamp of figure 9 in a second handling configuration;

[0030] [Fig.19] is a plan view of salient elements of an example of a clamp of the invention; R012471 PCT Deposit Text.docx

[0031] [Fig.20] is a side cross-sectional view of a ball joint during manipulation with pliers as shown in Figure 13.

[0032] Figures 1 and 2 are perspective views of an example of a manipulator gripper 1 according to a first embodiment of the invention. The gripper 1 is designed to grip a ball joint, allowing its manipulation by a practitioner, as well as its use for controlling a tool-holding robot. The gripper 1 includes a gripping handle 2. The gripper 1 is equipped with two movable jaws 31 and 32 relative to each other so as to modify the distance between these two jaws. This distance allows a ball joint to initially pass between the jaws 31 and 32, and then to grip the ball joint to fix the gripper 1 to it. The jaws 31 and 32 can advantageously be spaced apart over a range of 30 to 50 mm to allow a ball joint to be selectively passed through or clamped between these jaws 31 and 32. This spacing can advantageously be reduced to 20 mm, or even to 15 mm.This spacing can also be increased up to 70mm.

[0033] The movable jaws 31 and 32 are attached to the gripping handle 2. A movement exerted by the practitioner on the gripping handle 2 thus allows the position of the patella held between the jaws 31 and 32 to be changed. The clamp 1 also includes a control device 4 for the spacing between the two jaws 31 and 32. The clamp 1 further includes optical reflectors attached to the gripping handle 2. An example of optical reflectors will be described in detail later. Optical reflectors can, in particular, be used to reflect infrared radiation. Optical reflectors are used, as is known, to be identified by sensors in order to determine their position in space.

[0034] Thus, the use of a gripper 1 according to the invention allows for the precise localization of the gripper 1 in space relative to a ball joint, on which a three-dimensional scan or bone shape scan is performed. The position of the gripper 1 and the ball joint are then perfectly identified for the control of a tool-holding robot (not shown). The tool-holding robot can then constrain the movements of the tools relative to the ball joint and the gripper 1 in real time, in order to prevent operational incidents. The tools are typically saws or milling cutters. R012471 PCT Deposit Text.docx used to shape one face of a kneecap to which a prosthesis is to be attached.

[0035] Figure 3 is an enlarged view of the jaws 31 and 32 of the gripper 1. As illustrated, the gripping handle 2 has a housing 6 relative to which the movable jaws 31 and 32 are mounted to pivot or slide. In the example shown, the movable jaws 31 and 32 are mounted to pivot relative to the housing 6. The housing 6 here serves to protect parts of the gap control device 4. The housing 6 can also serve to hold optical reflectors. As can be seen in particular from Figure 7, the optical reflectors 5 are mounted projecting from the housing 6.

[0036] Figures 4 and 5 provide a clearer visualization of an example of a gap control device 4, in the absence of the housing 6. The device 4 here comprises a knob 41 pivotally mounted relative to the handle 2 around a longitudinal axis. The knob 41 drives a shaft mounted to rotate relative to the handle 2. A worm gear 42 drives the jaws 31 and 32 in rotation around longitudinal axes, allowing their gap to be adjusted along a transverse axis. More precisely, the gear 42 includes helical teeth formed at one end of the shaft. The helical teeth mesh with two spur gears, pivotally mounted relative to the housing 6 around transverse axes. Each of these spur gears includes a bevel-tooth protrusion about its axis. These conical teeth are coupled with conical teeth attached to jaws 31 and 32.

[0037] Thus, by turning the knob 41, a simultaneous rotation of the same amplitude is obtained for the jaws 31 and 32. Furthermore, a worm gear drive allows the position of the jaws to be automatically locked at the end of the manipulation of the knob 41.

[0038] The wheel 41 is advantageously removable when combined with a worm gear drive, since such a mechanism is automatically locked in position. R012471 PCT Deposit Text.docx

[0039] Device 4 may also have an alternative design. Such device 4 may be equipped with a locking mechanism for the gap between the jaws 31 and 32, so that the clamp 1 remains firmly attached to a ball joint 91 after it has been clamped.

[0040] Figure 8 is an enlarged view of the jaws 31 and 32 clamping a ball joint 91. A milling cutter 92 positioned in a workspace 94 for tools has been schematically illustrated.

[0041] As shown in Figure 5, the jaws 31 and 32 each comprise two projecting elements forming an acute angle at their ends, in order to grip securely onto the ball joint. Thus, the jaw 31 has two such projecting elements 311 and 312. The projecting elements will advantageously be moved by the device 4 so as to remain in the same plane.

[0042] If we define a plane passing through the projecting elements of jaws 31 and 32, the manipulator clamp 1 provides a first free space opposite jaws 31 and 32 for the passage of tendons on one side of this plane. This free space is therefore outside clamp 1. The manipulator clamp also provides a second free space 94 opposite jaws 31 and 32 for the passage of tools on a second side of this plane. This free space 94 is therefore inside clamp 1.

[0043] Figure 6 is a front view of an example of an optical reflector system 5. Figure 7 is a side cross-sectional view of the clamp 1 carrying this system.

[0044] In this example, the reflectors 5 are arranged on the same support. Alternatively, the reflectors 5 can be fixed independently at different locations on the clamp 1.

[0045] The reflectors 5 typically comprise a frame 50 and at least one reflector element 52 attached to the frame 50. In the illustrated example, 4 reflector elements 52 are attached to a frame 55 of the frame 50.

[0046] Advantageously, the frame 50 is selectively removable from the grip handle 2. Thus, different reflectors 5 can be attached to the handle 2 and the handle 2 can also be more compact for storage. R012471 PCT Deposit Text.docx

[0047] For this purpose, the frame 50 has a threaded end 53 intended to be screwed into the gripping handle 2. In the illustrated example, the frame 50 is fixed in the gripping handle by several threaded ends 53. The threaded ends 53 are typically provided on rods 51, driven in rotation relative to the frame 50 by means of wheels 54.

[0048] Advantageously, the gripping handle 2 has a first axial end 23 with distinct mounting locations 61 allowing the removable attachment of a frame 50 in different orientations relative to the handle 2. Thus, in the illustrated example, mounting locations 61 are arranged on the different faces of the housing 6, which has a parallelepiped shape. Each face has four mounting locations. The mounting locations 61 correspond to threaded bores.

[0049] The gripping handle 2 advantageously includes a second axial end 24. This axial end 24 also includes a fixing location allowing the removable attachment of a frame 50. These locations can also be arranged on different faces of the axial end 24.

[0050] Figures 9 to 11 are different views of an example of a manipulation clamp 1 according to a second example of an embodiment of the invention.

[0051] The clamp 1 has jaws 31 and 32 with an adjustable gap along the longitudinal axis. One of these jaws has two hooks 33 and 34 separated from each other along the transverse axis, allowing access along the first axis to a space between the jaws. The other jaw 32 also has two hooks 35 and 36 separated from each other along the transverse axis.

[0052] An example of the use of a clamp 1 according to the invention will be detailed. Figure 16 illustrates, in side view, a patella 91 with its patellar tendons 95 and the quadriceps tendons 96. Figure 17 illustrates a configuration of the clamp 1 (here the clamp of Figure 9) in which the free space 94 is inside the clamp 1. R012471 PCT Deposit Text.docx

[0053] In practice, the manipulation clamp 1 also allows for another mode of operation: passing the tendons on the second side of the plane and the tools on the first side of the plane. Figure 18 illustrates the configuration in which the free space 94 is outside the clamp 1. Such a configuration proves particularly advantageous for a surgical procedure: by leaving the clamp 1 fixed on the patella 91, it is possible to perform its machining, conduct adaptation tests with the prosthesis, and make a machining correction, all while keeping the clamp 1 fixed and therefore without losing the positioning reference of this clamp 1 relative to the patella 1.

[0054] In both configurations, it can be observed that the machining surfaces of the ball joint 91 are very large, allowing machining at various angles and with tools such as saw blades or milling cutters. Machining is thus possible in the plane including the protruding elements of the jaws 31 and 32. The shape of the machining operations performed on the ball joint 91 is therefore independent of the shape of the collet 1.

[0055] As illustrated in the gripper examples in Figures 1 and 9, the projecting elements extend perpendicularly from the arms. In the example in Figure 9, the projecting elements 33 to 36 extend perpendicularly from the first end of their respective arms. The arms are driven by their second end. This allows the gripping area to be offset from the arm drive area, thus freeing up as much space as possible in the gripping zone. Furthermore, it can be seen that in the plane encompassing the projecting elements 33 to 36, the spaces between two successive projecting elements are free, which allows access for tools.

[0056] These spaces 97 are illustrated in dotted lines in figure 19 which corresponds to a view in the plan including the salient elements 33 to 36.

[0057] The wheel 41 drives gears that slide the hooks 33 to 36 along the longitudinal axis. The rotation causes the jaws 31 and 32 to slide in opposite directions simultaneously and with the same amplitude.

[0058] Figure 12 is a top view of the jaws 31 and 32 of the clamp 1 gripping a ball joint 91. As illustrated, the design of these jaws 31 and 32 allows the passage of a saw 93 or a milling cutter 92. R012471 PCT Deposit Text.docx

[0059] The invention also relates to a method for controlling a tool-carrying robot, this method comprising, for example, the steps of: -filming a space in which a manipulation clamp 1 is positioned; -by digital processing, identify the position of the optical reflectors 5 in the filmed space, and determine the position of the manipulation clamp 1 from the position of the optical reflectors 5 identified; -to restrict the movement of a robot tool relative to the handling gripper according to the position determined for the handling gripper 1.

[0060] According to another aspect of the invention, the method for controlling the tool-holding robot comprises the steps of: -filming a space in which a manipulation clamp 1 is positioned; -by digital processing, identify the position of the optical reflectors 5 in the filmed space, and determine the position of the manipulation clamp 1 from the position of the identified optical reflectors 5, determine the shape and position of the filmed ball joint; -to restrict the movement of a robot tool relative to the ball joint according to the determined shape and position of the ball joint.

[0061] The process is thus used to restrict the movement of the robot's tools by the practitioner, in order to avoid any handling errors.

[0062] In the preoperative phase, the scan necessitates additional work to dimension the patella. This leads to preoperative planning of the tibial implant, femoral implant, and patellar implant.

[0063] Pre-operative planning allows for the positioning of the femoral implant, the patellar implant and a simulation of the patellar race.

[0064] A preliminary operation is usually performed with positioning of the tibial and femoral implant.

[0065] Then the patella is exposed with partial or complete eversion, depending on the surgeon's preference. Typically, such a robot is activated to perform the bone preparation of the patellar surface. Two techniques can be used for this: R012471 PCT Deposit Text.docx

[0066] -either a bone cut is made with an oscillating saw, followed by milling to create the implant positioning pads;

[0067] -either we perform a milling of the implant impression with the creation of the pads during two successive steps.

[0068] The surface is then cleaned of milling residue, and the trial patellar implant can be positioned. Clamp 1 is then removed. The surgeon can then check the patellar travel before proceeding with the placement of the definitive implants.

[0069] Figures 13 to 15 are different views of another embodiment of a clamp 1 according to the invention. The clamp 1 is also designed to grip a ball joint, allowing its manipulation by a practitioner, as well as its use for controlling a tool-holding robot. The clamp 1 also includes a gripping handle 2. The clamp 1 is equipped with two movable jaws 31 and 32 relative to each other so as to modify the gap between these two jaws.

[0070] The movable jaws 31 and 32 are fixed to the gripping handle 2. A movement exerted by the practitioner on the gripping handle 2 thus allows the position of the patella held between the jaws 31 and 32 to be modified. The forceps 1 also includes a control device 4 for the spacing between the two jaws 31 and 32. The forceps 1 further includes optical reflectors fixed to the gripping handle 2.

[0071] In the illustrated example, the movable jaws 31 and 32 are pivotally mounted relative to the handle 2. The handle 2 here serves to protect parts of the gap control device 4. The handle 2 can also be used to attach optical reflectors. For example, the optical reflectors 5 are mounted projecting from the handle 2 at the ends of radial shafts 56. The shafts 56 are fixed in threaded bores in the handle 2.

[0072] The device 4 includes a knob 41 mounted pivotally relative to the handle 2 about a longitudinal axis. The knob 41 drives a shaft mounted to rotate relative to the handle 2. A gear allows the jaws 31 and 32 to rotate about a vertical axis, in order to adjust their R012471 PCT Deposit Text.docx spacing along a transverse axis. Thus, by turning the knob 41, a simultaneous rotation of the same amplitude is obtained for the jaws 31 and 32. Such a device 4 can be equipped with a locking mechanism for the spacing between the jaws 31 and 32, so that the clamp 1 remains firmly attached to a ball joint after it has been clamped.

[0073] Jaws 31 and 32 here include rounded profiles to fit the lateral edge of a ball joint, with teeth to ensure a good grip on this edge.

[0074] Regardless of the geometry of the jaws 31 and 32 (the jaws of other embodiments can, for example, be used in combination with the positioning support described later), the clamp 1 advantageously features a pre-positioning support for the ball joint in a vertical direction. This positioning support is movable in a direction perpendicular to the clamping plane of the jaws 31 and 32. The positioning support is movable so as to be able to position itself between the jaws 31 and 32, as illustrated in Figure 13. The positioning support is thus positioned between the jaws 31 and 32, in a projection view in the plane including these jaws 31 and 32. The positioning support can thus be brought closer to the plane including the jaws 31 and 32. For this purpose, the clamp 1 advantageously includes an arm 71 movable in the vertical direction.The arm 71 can thus move a ball joint closer to or further from the jaws 31 and 32, allowing the jaws 31 and 32 to be correctly positioned relative to the edge of the ball joint. The arm 71 is mounted here to pivot about a transverse axis relative to the handle 2.

[0075] Figure 20 illustrates the advantage of this clamp 1: the arm 71 (in particular the plate 711) allows the patella 91 to be moved to the desired level before the jaws 31 and 32 are fixed to the patella 91. The jaws 31 and 32 can thus be positioned relative to the tendons 95 and 96 to expose a maximum volume of the patella 91 for machining, typically flush with the soft tissues or tendons.

[0076] The ball head positioning support advantageously includes a locking mechanism for its positioning. The movement of the arm 71 is R012471 PCT Deposit Text.docx controlled by a handle 72, which rotates the arm 71 via gears (not shown). To provide resistance to the movement of the handle 72, a leaf spring 74 is interposed between the handle 2 and the handle 72. To immobilize the handle 72, and therefore the arm 71, in a desired position, the clamp 1 also includes a knurled wheel 73 screwed onto a threaded shaft 75 attached to the handle 2 and passing through the handle 72. The spring 74 also allows the handle 72 to be pushed against the knurled wheel 73. R012471 PCT Deposit Text.docx

Claims

Demands

1. A manipulation clamp (1) for a ball joint (91), characterized in that it comprises: -a gripping handle (2); -two movable jaws (31, 32) relative to each other so as to modify the spacing between these two jaws, the movable jaws being integral with the gripping handle, the two jaws each comprising two protruding elements and forming an acute angle at their end, the ends of the protruding elements of the jaws being in a plane, the handling clamp providing a first free space opposite the jaws, and providing a second free space opposite the jaws for the passage of tools on a second side of this plane opposite the first; -a control device (4) for the gap between the two jaws (31, 32); - optical reflectors (5) attached to the gripping handle.

2. Handling clamp according to claim 1, in which said gripping handle (2) comprises a housing (6) relative to which said movable jaws (31, 32) are mounted pivotally or sliding, said reflectors (5) being mounted projecting relative to said housing (6).

3. Handling clamp according to claim 2, wherein said reflectors (5) comprise a frame (50) and at least one reflector element (52) fixed to the frame.

4. Handling clamp according to claim 3, wherein the frame (50) is selectively removable from the gripping handle (2).

5. Handling clamp according to claim 4, wherein the frame (50) has a threaded end (53) screwed into the gripping handle (2).

6. A handling gripper according to claim 4 or 5, wherein the gripping handle (2) has a first axial end (23) having distinct fixing locations for fixing R012471 PCT Deposit Text.docx removable from a frame (50) according to different orientations relative to the gripping handle.

7. Handling clamp according to claim 6, in which the gripping handle (2) has a second axial end (24) having a fixing location allowing the removable fixing of a frame (50).

8. A handling clamp according to any one of the preceding claims, in which the control device (4) for the gap between the two jaws (31, 32) comprises a drive wheel (41) driving said jaws via a worm gear (42), the wheel being pivotally mounted relative to said gripping handle and its pivoting modifying the gap between said jaws (31, 32).

9. Handling clamp according to any one of the preceding claims, wherein the gap control device (4) includes a gap locking mechanism between the two jaws (31, 32).

10. A handling clamp according to any one of the preceding claims, wherein the two movable jaws (31, 32) can be at least spread apart over a range of 30 to 50 mm.

11. A manipulator clamp according to any one of the preceding claims, wherein the first free space opposite the jaws is for the passage of tendons on a first side of this plane.

12. A handling clamp according to any one of the preceding claims, wherein the jaws have an adjustable gap about a first axis, one of said jaws having two hooks separated from each other about a second axis perpendicular to the first, so as to allow access along the first axis to a space between said jaws.

13. A handling clamp according to any one of the preceding claims, further comprising a support for R012471 PCT Deposit Text.docx 15. Positioning of the movable ball joint in a direction perpendicular to said plane.

14. Handling clamp according to claim 13, wherein the positioning support is movable so as to be able to position itself between the jaws 31 and 32.

15. A handling clamp according to claim 14, wherein the positioning support is movable so as to be able to be brought closer to said plane.

16. Handling clamp according to claim 13 or 14, wherein the positioning support includes a plate (711) configured to be moved vertically relative to said plane.

17. A method for controlling a tool-carrying robot, comprising the steps of: -filming a space in which is positioned a manipulation clamp (1) of a ball joint (91) comprising a gripping handle (2), two jaws (31, 32) separated from each other and attached to the gripping handle (2) and optical reflectors (5) attached to the gripping handle (2); -by digital processing, identify the position of the infrared reflectors (5) in the filmed space, determine the position of the manipulation clamp (1) from the position of the optical reflectors (5) identified; -to restrict the movement of a robot tool relative to the handling gripper according to the position determined for the handling gripper.

18. A method for controlling a tool-carrying robot, comprising the steps of: -filming a space in which is positioned a manipulation clamp (1) of a ball joint (91) comprising a gripping handle (2), two jaws (31, 32) separated from each other and attached to the gripping handle (2) and optical reflectors (5) attached to the gripping handle (2), a ball joint being held between the two jaws; -using digital processing, identify the position of the infrared reflectors (5) in the filmed space, determine the position of the manipulation clamp (1) from the identified position of the optical reflectors (5), determine the shape R012471 PCT Deposit Text.docx 16 and the position of the filmed ball joint; -to restrict the movement of a robot tool relative to the ball joint according to the determined shape and position of the ball joint.

19. A method for controlling a tool-carrying robot according to claim 17 or 18, wherein the two movable jaws (31, 32) of said manipulator gripper (1) positioned in the filmed space are movable relative to each other so as to modify the spacing between these two jaws, and wherein said gripper handle includes a control device (4) for the spacing between the two jaws (31, 32).

20. Control method according to claim 19, wherein said gripping handle (2) of the handling gripper comprises a housing (6) relative to which said movable jaws (31, 32) are mounted pivotally or sliding, said reflectors (5) being mounted projecting relative to said housing (6).

21. A control method according to claim 20, wherein said reflectors (5) comprise a frame (50) and at least one reflector element (52) fixed to the frame.

22. A control method according to claim 21, wherein the frame (5) is selectively removable from the gripping handle (2).

23. Control method according to claim 22, wherein the frame (5) has a threaded end (53) screwed into the gripping handle (2).

24. A control method according to claim 22 or 23, wherein the gripping handle (2) has a first axial end (23) having distinct fixing locations allowing the removable fixing of a frame (50) in different orientations relative to the gripping handle.

25. Control method according to claim 24, wherein the gripping handle (2) has a second axial end (24) having a fixing location allowing the removable fixing of a frame (50). R012471 PCT Deposit Text.docx R012471 PCT Depot Texte. docx

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