Locking mechanism

Abstract

The invention relates to a locking mechanism comprising: a movable pawl (34) pivotally mounted between a locking position and a released position, the movable pawl comprising a cam surface (36); a thrust device (38) comprising a cam follower (42) moving on the cam surface to move the movable pawl from the released position to the locking position; an actuating lever (3) moving the thrust device and comprising a first notch and a second notch; a positioning member (2) engaging in the first notch in the locking position and in the second notch in the released position; the positioning member comprising a flexible blade (200) comprising a shape folded back on itself to form a V-shape. (Abstract Figure: 2)

Description

Title of the invention: Locking mechanism Technical field

[0001] The present invention relates to a locking mechanism for locking the rotation of a shaft of a transmission chain of a mobility device, such as a motor vehicle for example. Technological background

[0002] Locking mechanisms are used, for example, as a parking brake to secure a stationary motor vehicle. In such a case, they make it possible to lock a drive shaft of the motor vehicle in rotation. Such locking mechanisms are used in particular in motor vehicles with automatic transmission, in hybrid vehicles or in electric vehicles.

[0003] It is known, in particular from document US2018 / 0112774, locking mechanisms comprising a movable pawl equipped with a locking finger and pivotally mounted on a transmission casing between a released position and a locking position in which the locking finger is inserted into a locking recess integral in rotation with the transmission shaft to be locked. The locking mechanism further comprises a thrust device guided in translation on the transmission casing and comprising a cam follower which cooperates with a cam surface of the pawl so that a translational movement of the thrust device causes the pawl to pivot between the released position and the locking position.

[0004] An actuating lever is used to actuate the movement of the thrust device. The actuating lever is pivotally mounted on the transmission housing and driven in rotation, directly or indirectly, by the rotor shaft of an electric motor.

[0005] Most often, the actuating lever comprises an external periphery having a first and a second angular positioning notch. A positioning member fixed to the transmission casing comprises an elastic device, for example in the form of a flexible blade, pressing on the external periphery of the actuating lever. The positioning member is configured to engage in the first angular positioning notch when the movable pawl is in the locked position, and in the second angular positioning notch when the movable pawl is in the released position.

[0006] The positioning member thus makes it possible to maintain the position of the locking mechanism in a stable and precise manner in the released position and / or in the locked position.

[0007] Such a structure of the locking mechanism poses several technical problems: • Firstly, compactness must be improved in order to accommodate the locking mechanism in the very limited spaces allocated to recent transmissions, particularly transmissions for electric vehicles. • Secondly, the assembly must be simplified. In particular, the various components of the locking mechanism can be fixed to the transmission housing along fixing axes that are not parallel to each other, which means that their assembly involves several complex operations. • Finally, these improvements in compactness and assembly must be able to be obtained while maintaining sufficient mechanical strength of the positioning member which is subjected to the mechanical stresses occurring during the vehicle stopping phases ensured by the locking mechanism. Summary

[0008] In all that follows, ordinal numeral adjectives are used to differentiate characteristics. They do not define the position of a characteristic. Therefore, for example, a third characteristic of a product does not mean that the product has a first and / or a second characteristic.

[0009] An idea underlying the invention is a locking mechanism intended to lock a shaft of a vehicle in rotation.

[0010] An idea underlying the invention is a blocking mechanism which makes it possible to solve one or more technical problems of the prior art, for example the aforementioned problems.

[0011] The invention relates to a locking mechanism capable of being mounted in a transmission casing for locking in rotation a shaft of a vehicle equipped with at least one locking recess, the locking mechanism comprising: • a movable pawl comprising a locking finger, the movable pawl being pivotally mounted about a pivot axis between a locking position in which the locking finger is engaged in the locking recess and a released position in which the locking finger is disengaged from said locking recess, the movable pawl comprising a cam surface; • a thrust device comprising a cam follower capable of moving on the cam surface in order to move the movable pawl from the released position to the locking position; • an actuating lever pivotally mounted about an actuating axis configured to move the thrust device, the actuating lever comprising an external periphery comprising a first angular positioning notch and a second angular positioning notch; And • a positioning member cooperating with the external periphery of the actuating lever, the positioning member comprising a bearing surface configured to engage in the first angular positioning notch when the movable pawl is in the locked position and in the second angular positioning notch when the movable pawl is in the released position; the positioning member comprising a flexible blade exerting a force, directly or indirectly, on the external periphery of the actuating lever, the flexible blade comprising a shape folded back on itself to form a V shape.

[0012] According to another aspect of the invention, the invention relates to a locking mechanism capable of being mounted in a transmission casing for locking in rotation a shaft of a vehicle equipped with at least one locking recess, the locking mechanism comprising: • a movable pawl comprising a locking finger, the movable pawl being capable of being pivotally mounted about a pivot axis on the transmission casing between a locking position in which the locking finger is engaged in the locking recess and a released position in which the locking finger is disengaged from said locking recess, the movable pawl comprising a cam surface; • a thrust device comprising a cam follower capable of moving on the cam surface in order to move the movable pawl from the released position to the locking position; • an actuating lever being capable of being pivotally mounted about an actuating axis on the transmission casing and being configured to move the thrust device, the actuating lever comprising an external periphery comprising a first angular positioning notch and a second angular positioning notch; and

[0013] the positioning member comprising a flexible blade exerting a force, directly or indirectly, on the external periphery of the actuating lever, the flexible blade comprising a shape folded back on itself to constitute a V shape.

[0014] For the purposes of this application: • “axially” means “parallel to the actuation axis”; • “radially” means “along an axis belonging to a plane orthogonal to the actuation axis and intersecting this actuation axis”; • “angularly” or “circumferentially” means “around the axis actuation”; • the terms "external" and "internal" are used to define relative position of a component relative to the axis of rotation for which it is concentric, a component close to said axis is thus qualified as internal as opposed to an external component located radially on the periphery; • two parts are said to be “fixed” or “rigidly secured” when they are permanently immobilized relative to each other, this immobilization being able to result from a fixing of the first part on the second part directly or by means of one or more intermediate parts.

[0015] The flexible blade is a simple and economical solution which allows easy determination of a geometry compatible with a limited available space while ensuring sufficient stiffness and mechanical resistance to maintain the locking mechanism in position.

[0016] The V-shape makes it possible to obtain, in a limited available volume, a flexible blade having a bending portion of significant length. In comparison with the flexible blades having a flat or weakly bent bending portion of the prior art, the V-shaped blade can make it possible to obtain equivalent stiffness and mechanical strength, while occupying a smaller footprint, typically a reduction of 20 to 60% of circumferential footprint.

[0017] According to an additional characteristic of the invention, the V-shape comprises a first flat wall and a second flat wall, a folding angle being established between the first flat wall and the second flat wall, the folding angle being between 0° and 80°, the folding angle preferably being between 0° and 40°.

[0018] The bending angle according to this latter characteristic makes it possible to minimize the size of the radially flexible blade. The angle value chosen also makes it possible to adjust the value of the force exerted by the flexible blade on the external periphery of the actuating lever.

[0019] According to an additional characteristic of the invention, a curved wall connects the first flat wall and the second flat wall.

[0020] According to an additional characteristic of the invention, the curved wall has a radius of curvature of between 2 mm and 10 mm.

[0021] According to an additional characteristic of the invention, a radius of curvature of the curved wall, a thickness of the flexible blade and a ratio equal to the ratio between the radius of curvature and the thickness of the flexible blade are established, the ratio being between 2 and 8.

[0022] The curved wall as defined according to these last three characteristics makes it possible to adapt the stiffness of the flexible blade while limiting the concentrations of mechanical stresses in it.

[0023] According to an additional characteristic of the invention, the first flat wall and the second flat wall are parallel to the actuation axis.

[0024] According to an additional characteristic of the invention, the positioning member comprises a rolling element arranged on the flexible blade, the rolling element being configured to roll on the external periphery of the actuating lever.

[0025] The rolling element makes it possible to improve the durability of the locking mechanism by limiting wear and relative friction between the external periphery of the actuating lever and the flexible blade.

[0026] Advantageously, the rolling element may be a cylindrical roller. A complementary shape may then be provided on the end of the flexible blade in order to constitute a pivot connection between the cylindrical roller and the flexible blade.

[0027] According to an additional characteristic of the invention, the flexible blade comprises a first folded fixing lug and a second folded fixing lug, the first and second folded fixing lugs being folded at an angle of 90° from a first portion of the flexible blade and positioned axially on either side of said first portion of the flexible blade.

[0028] Thanks to this latter characteristic, the flexible blade has a fixing zone on either side of its bending part, which has the effect of evenly distributing the absorption of forces in the flexible blade and thus reducing the mechanical stresses in it.

[0029] According to an additional characteristic of the invention, the first folded fixing tab is folded in a direction opposite to the second folded fixing tab.

[0030] This latter feature allows the first folded fixing lug not to be axially opposite the second folded fixing lug. Thus the first folded fixing lug does not hinder the passage of a fixing tool to access the second folded fixing lug, and vice versa. Access to the first and second folded fixing lugs for fixing the positioning member is thereby simplified.

[0031] According to an additional characteristic of the invention, the first folded fixing lug and the second folded fixing lug are offset from each other axially in a direction parallel to the actuation axis.

[0032] Thanks to this architecture, the assembly of the actuating lever and the positioning member is carried out along parallel axes. They can therefore be easily mounted together during the same assembly operation. The axial offset of the first folded fixing lug relative to the second folded fixing lug simplifies the assembly of the positioning member by carrying it out sequentially, with in a first step a pre-positioning via the first folded fixing lug, the first folded fixing lug having for example a hole to be inserted on a centering pin fixed to the transmission casing, then in a second step a complete immobilization via the second folded fixing lug, at for example by means of a screw connecting the second bent fixing lug to the transmission housing.

[0033] According to an additional characteristic of the invention, the locking mechanism comprises: • a first fixing means, in particular a centering pin, cooperating with the first folded fixing tab to block the movement of the positioning member in a plane perpendicular to the actuation axis; and • a second fixing means, in particular a screw, cooperating with the second folded fixing tab to block the movement of the positioning member along an axis parallel to the actuation axis.

[0034] The fixing of the positioning member according to this latter characteristic can be carried out relative to any type of component on which the locking mechanism can be mounted, in particular the transmission casing.

[0035] Thus the fixing of the positioning member is carried out isostatically. In other words, all degrees of freedom of movement of the positioning member are blocked, while guaranteeing easy assembly without risk of deformation of components.

[0036] According to an additional characteristic of the invention, the folded fixing tab comprises a first cutout, preferably circular, configured to be centered and adjusted on a centering pin, a first diametrical clearance being defined between the circular cutout and the centering pin, preferably the first diametrical clearance being between 0.05 and 0.2 mm.

[0037] According to an additional characteristic of the invention, the second folded fixing lug comprises a second cutout, preferably circular, configured to cooperate with the body of a screw, a second diametrical clearance being defined between the second cutout and the body of the screw, the second diametrical clearance being greater than the first diametrical clearance, preferably the second diametrical clearance being greater than 0.5 mm.

[0038] Thanks to this latter characteristic, the risk of assembly being impossible due to manufacturing tolerances of the components is eliminated.

[0039] According to an additional characteristic of the invention, the positioning member is fixed to the transmission casing.

[0040] According to an additional characteristic of the invention, the actuating lever is pivotally mounted on the transmission casing.

[0041] According to an additional characteristic of the invention, the movable pawl is pivotally mounted on the transmission casing.

[0042] According to an additional characteristic of the invention, the transmission casing comprises support surfaces positioned by complementary shape opposite the first and second folded fixing tabs of the positioning member.

[0043] According to an additional characteristic of the invention, the flexible blade has a shape configured to leave a free passage along an axis parallel to the actuation axis allowing the assembly of the first and second fixing means.

[0044] This latter characteristic makes it possible to define the general shape of the flexible blade so that no part of it hinders the passage of a fixing tool. Access to the first and second bent fixing tabs for fixing the positioning member is thus simplified.

[0045] According to an additional characteristic of the invention, the actuation axis of the actuation lever is parallel to the pivot axis of the movable pawl.

[0046] Thanks to this feature, the assembly can be further simplified because all the components of the locking mechanism mounted on the transmission housing can be mounted along parallel axes, they can therefore all be mounted during the same assembly operation.

[0047] According to an additional characteristic of the invention, the external periphery of the actuating lever is made up of surfaces parallel to the actuating axis.

[0048] According to an additional characteristic of the invention, the actuating lever is formed from a plate cut from a sheet of constant thickness, the external periphery of the actuating lever being obtained from a cut edge of the plate.

[0049] Thus, the actuating lever can be produced using a simple and economical manufacturing process.

[0050] According to an additional characteristic of the invention, the flexible blade deforms elastically and / or radially while traveling around the external periphery of the actuating lever.

[0051] According to an additional characteristic of the invention, the flexible blade is formed in a single piece from a strip of metallic material, in particular from a steel sheet.

[0052] Thus the manufacturing process is simple and economical: from a sheet of constant thickness, typically between 0.5 and 2 mm, a cutting operation, for example press cutting, is carried out to cut the external and internal contours of the flexible blade, followed by a folding operation to give it the V shape.

[0053] According to an additional characteristic of the invention, the flexible blade is manufactured from a metal which has undergone a hardening treatment, in particular carbonitriding, nitriding, carburizing or quenching.

[0054] This feature makes it possible to increase the mechanical resistance of the flexible blade. necessary to withstand the mechanical stresses transmitted to the locking mechanism.

[0055] According to an additional characteristic of the invention, the flexible blade has a stiffness of between 10 and 50 N / mm.

[0056] According to an additional characteristic of the invention, the flexible blade performs a radial displacement when the positioning member cooperates with the external periphery of the actuating lever, the radial displacement varying between 1 and 10 mm whatever the angular position of the actuating lever.

[0057] According to an additional characteristic of the invention, the actuating lever is driven in rotation, directly or indirectly, by a rotor shaft of an electric motor.

[0058] According to another of its aspects, the invention relates to a transmission system comprising a shaft equipped with at least one locking recess and a locking mechanism as described previously.

[0059] The invention further relates to a motor vehicle comprising a transmission system as defined above. Brief description of the figures

[0060] [Fig-1] [Fig.l] is a front view of a locking mechanism according to a method of realization of the invention.

[0061] [Fig.2] [Fig.2] is a perspective view of [Fig.l].

[0062] [Fig.3] [Fig.3] is a perspective view of part of the locking mechanism according to one embodiment of the invention.

[0063] [Fig.4] [Fig.4] is a top view of [Fig.3].

[0064] [Fig.5] [Fig.5] is a perspective view of a positioning member according to a embodiment of the invention.

[0065] [Fig.6] [Fig.6] is a front view of [Fig.5].

[0066] [Fig.7] [Fig.7] is a perspective view of an actuating lever according to a embodiment of the invention. Description of the embodiments

[0067] In all the figures, identical elements or elements providing the same function bear the same reference numbers. The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment or that the characteristics apply only to a single embodiment. Single characteristics of different embodiments can also be combined or interchanged to provide other embodiments.

[0068] A mechanism for locking the rotation of a shaft of a vehicle comprises including: a movable pawl, a pushing device, an actuating lever and a positioning member. The locking mechanism is intended in particular to immobilize a vehicle, for example a car, in a parked state. The various elements of the locking mechanism will be presented below.

[0069] Figures 1 and 2 illustrate a locking mechanism according to one embodiment of the invention. In these figures, the locking mechanism comprises a movable pawl 34 located in a transmission housing 1 (partially shown). The movable pawl 34 may be of elongated shape and may have a first end 71 and a second end 72 distant from the first end 71.

[0070] The first end 71 allows for example the fixing of the movable pawl 34 on the transmission casing 1 while allowing the rotational movement of said movable pawl 34. That is to say that the movable pawl is pivotally mounted in a plane P around a pivot axis Yl.

[0071] The second end 72 may comprise a cam surface 36 located on a first lateral face of the movable pawl 34. The second end 72 may further comprise a locking finger 35 projecting from a second lateral face of the movable pawl 34. The locking finger 35 is intended, when the locking mechanism is engaged, to be inserted into a locking recess 45. The locking recess 45 is for example located on a ratchet wheel 44 which is capable of receiving said locking finger 35, and which is fixed in rotation with the transmission shaft 60 (partially shown) intended to be locked in rotation.

[0072] Thus, the locking mechanism varies between a locking position in which the locking finger 35 is engaged in the locking recess 45 and a released position in which the locking finger 35 is disengaged from said locking recess 45. In Figures 1 and 2, the mechanism for locking the rotation of a shaft is shown in a released position.

[0073] The movable pawl 34 may further comprise a torsion spring 50. The torsion spring 50 is for example wound at the first end 71 of the movable pawl 34. The torsion spring 50 may comprise a first end 51 which bears against a bearing surface of the transmission casing 1 and a second end 52 which bears against a bearing surface of the movable pawl 34. The torsion spring 50 is arranged to exert a return force on the movable pawl 34 in order to return it to the released position.

[0074] The locking mechanism further comprises a thrust device 38. The thrust device 38 can be guided in a longitudinal direction X by a guide rail 27 housed in the transmission housing 1. In cases where the thrust device 38 is returned backwards by the movable pawl 34 during dynamic phases, the thrust device 38 can come into abutment against a side wall of the guide rail 27. guide 27, which thus forms a non-return stop for the thrust device 38. The thrust device 38 is in this case sent against the movable pawl 34 by a return force exerted by a tension spring 40. This effect can occur for example during attempts to engage at too high a speed. Beyond a threshold speed, for example between 3 km / h and 5 km / h, the movable pawl 34 rebounds to prevent engagement, the thrust device 38 is then returned to the stop. The spring 40 surrounds a rod 39 of the thrust device which develops through a first notch 25 of the transmission casing 1 and a second notch 32 of the guide rail 27.

[0075] The pushing device 38 may be in the form of a mobile carriage which comprises, for example, a first mobile roller 41 capable of moving along a longitudinal wall 30 of the guide rail 27. The pushing device 38 may further comprise a cam follower 42 comprising a second mobile roller which is in contact with the cam surface 36 of the mobile pawl 34 and capable of moving along this cam surface 36.

[0076] The pushing device 38 may further comprise a lug 43 located at the second end of the movable pawl 34. The lug 43 is intended to retain the movable pawl 34 in the plane P.

[0077] To move the movable pawl 34 into the locking position, the rod 39 can be moved through the second notch 32 of the guide rail 27, thereby moving the pushing device 38 in the longitudinal direction X. The movement of the pushing device 38 can cause the first movable roller 41 to move along the guide rail 27 and the cam follower 42 to move along the cam surface 36 of the movable pawl 34. The cam surface 36 can have a slope and the pushing device 38 can therefore exert, via its movement, pressure in the direction of the cam surface 36 of the movable pawl 34. This pressure can cause the second end of the movable pawl 34 to rotate in the direction of a locking recess such that the locking finger 35 can engage in a locking recess present, for example, on a ratchet wheel 44.

[0078] Figures 3 to 7 illustrate more particularly an actuating lever 3 and a positioning member 2 of the locking mechanism according to one embodiment of the invention.

[0079] The actuating lever 3 is pivotally mounted about an actuating axis Y2 on the transmission casing 1. A housing 101 (visible in [Fig.2]) arranged in the transmission casing 1 can cooperate with a stop ring 102 in order to axially block the actuating lever 3. The actuating lever 3 can be driven in rotation by a drive shaft 303, the drive shaft 303 cooperating in rotation to a rotor shaft of an electric motor, in particular via gears allowing a speed reduction to be achieved. The actuating lever 3 may be connected to the rod 39, for example via a pivot connection, such that a rotation of the actuating lever 3 around the actuating axis Y2 causes a translation in the longitudinal direction X of the thrust device 38.

[0080] As illustrated in [Fig.7], the actuating lever 3 further comprises an external periphery 300 comprising a first angular positioning notch 301 and a second angular positioning notch 302. The actuating lever 3 may be formed from a plate cut from a sheet of constant thickness, for example a thickness of between 3 and 6 mm, the external periphery 300 being obtained from a cut edge of the plate.

[0081] As illustrated by Figures 3 and 5, the positioning member 2 cooperates with the external periphery of the actuating lever 3, the positioning member 2 comprises a bearing surface 204 configured to engage in the first angular positioning notch 301 when the movable pawl 34 is in the locking position and in the second angular positioning notch 302 when the movable pawl 34 is in the released position. The positioning member 2 thus makes it possible to maintain the position of the locking mechanism in a stable and precise manner in the released position and / or in the locking position.

[0082] In this embodiment, the positioning member 2 comprises a flexible blade 200 exerting a force, directly or indirectly, on the external periphery 300 of the actuating lever 3. A rolling element 203, for example a cylindrical roller, arranged on the flexible blade 200 can be configured to roll on the external periphery 300 of the actuating lever 3.

[0083] The positioning member 2 can be fixed to the transmission casing 1 via a first folded fixing lug 201 and via a second folded fixing lug 202 of the flexible blade 200, the first folded fixing lug 201 and the second folded fixing lug 202 being able to be offset from each other in a direction parallel to the actuation axis Y2. Advantageously, the first folded fixing lug 201 and the second folded fixing lug 202 can be folded at an angle of 90° from a first portion 210 of the flexible blade 200 and positioned axially on either side of said first portion 210 of the flexible blade 200. The first folded fixing lug 201 can be folded in a direction opposite to the second folded fixing lug 202.

[0084] As illustrated in Figures 3 and 4, a first fixing means 205, here a centering pin, can cooperate with a circular hole in the first folded fixing lug 201 to limit the movement of the positioning member 2 relative to the transmission casing 1 in the plane perpendicular P to the axis actuating axis Y2. Advantageously, a first very small diametrical clearance, typically between 0.05 mm and 0.2 mm, is put in place between the circular hole and the centering pin. A second fixing means 206, here a screw, can cooperate with the second folded fixing tab 202 to block the movement of the positioning member 2 relative to the transmission casing 1 along a fourth axis Y4 parallel to the actuating axis Y2.

[0085] As illustrated in [Fig.4], four axes can be defined to carry out the assembly on the transmission casing 1: the actuation axis Y2 of the actuation lever 3, the pivot axis Y1 of the movable pawl 34, the fourth axis Y4 along which the screw 205 can be assembled and a third axis Y3 along which the centering pin 206 can be assembled. Advantageously, these four axes can be parallel, which makes it possible to easily mount all these components during the same assembly operation.

[0086] As illustrated in Figures 5 and 6, the flexible blade 200 comprises a shape folded back on itself to form a V-shape. The V-shape may comprise a first flat wall 207 and a second flat wall 208, a folding angle A being established between the first flat wall 207 and the second flat wall 208, the folding angle A preferably being between 0° and 40°, 30° in the example of [Fig. 6]. A curved wall 209 may connect the first flat wall 207 and the second flat wall 208, the curved wall 209 having a radius of curvature between 2 mm and 10 mm, 6.5 mm in the example of [Fig. 6]. Advantageously, the radius of curvature of the curved wall 209 can be chosen as a function of the thickness of the flexible blade 200 in order to improve the compromise between the stiffness and the mechanical stress thereof.A ratio equal to the ratio between the radius of curvature and the thickness of the flexible blade 200 can be established, the ratio preferably being between 2 and 8. In the example of [Fig.6], the thickness of the flexible blade 200 is 1.5 mm, the ratio is therefore 4.3.

[0087] The flexible blade 200 may be formed in one piece from a strip of metallic material. In the example of [Fig. 6], the flexible blade 200 is made from a strip of steel which is cut by press to obtain its contours, then folded to obtain its V shape, the first and second folded fixing tabs 201 and 202, and also a complementary shape 211 making it possible to constitute a pivot connection between the cylindrical roller 203 and the flexible blade 200. The flexible blade 200 may then undergo a hardening treatment in order to increase its mechanical strength.

[0088] The first flat wall 207 and the second flat wall 208 of the flexible blade 200 may be parallel to the actuation axis Y2. In addition, the shape of the flexible blade 200, in particular its V-shape and / or the choice of the value of the bending angle A, may be chosen so as to leave a passage free allowing the assembly of the first fixing means 205 along the fourth axis Y4 and the second fixing means 206 along the third axis Y3.

[0089] It is emphasized that all features, as they emerge for a person skilled in the art from the present description, the drawings and the attached claims, even if concretely they have only been described in relation to other determined features, both individually and in any combinations, can be combined with other features or groups of features disclosed herein, provided that this has not been expressly excluded or that technical circumstances make such combinations impossible or meaningless.

[0090] The use of the verb “comporter”, “comprendre” and its conjugated forms does not exclude the presence of other elements or other steps than those stated in a claim.

[0091] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

1. Claims Locking mechanism suitable for being mounted in a transmission housing (1) for locking in rotation a shaft of a vehicle equipped with at least one locking recess (45), the locking mechanism comprising: - a movable pawl (34) comprising a locking finger (35), the movable pawl (34) being pivotally mounted about a pivot axis (Yl) between a locking position in which the locking finger (35) is engaged in the locking recess (45) and a released position in which the locking finger (35) is disengaged from said locking recess (45), the movable pawl (34) comprising a cam surface (36); - a pushing device (38) comprising a cam follower (42) capable of moving on the cam surface (36) in order to move the movable pawl (34) from the released position to the locking position; - an actuating lever (3) pivotally mounted about an actuating axis (Y2) and configured to move the pushing device (38), the actuating lever (3) comprising an external periphery (300) comprising a first angular positioning notch (301) and a second angular positioning notch (302); and - a positioning member (2) cooperating with the external periphery (300) of the actuating lever (3), the positioning member (2) comprising a bearing surface (204) configured to engage in the first angular positioning notch (301) when the movable pawl (34) is in the locking position and in the second angular positioning notch (302) when the movable pawl (34) is in the released position; characterized in that the positioning member comprises a flexible blade (200) exerting a force, directly or indirectly, on the external periphery (300) of the actuating lever (3), the flexible blade (200) comprising a shape folded back on itself to constitute a V-shape.

2. The locking mechanism of claim 1, wherein the V-shape comprises a first planar wall (207) and a second planar wall (208), a folding angle (A) being established between the first planar wall (207) and the second planar wall (208), the folding angle (A) being between 0° and 80°, the folding angle (A) preferably being between 0° and 40°.

3. The locking mechanism of claim 2, wherein a curved wall (209) connects the first planar wall (207) and the second planar wall (208).

4. A locking mechanism according to claim 3, wherein the curved wall (209) has a radius of curvature of between 2 mm and 10 mm.

5. A locking mechanism according to claim 3 or 4, wherein a radius of curvature of the curved wall, a thickness of the flexible blade and a ratio equal to the ratio between the radius of curvature and the thickness of the flexible blade are established, the ratio being between 2 and 8.

6. A locking mechanism according to any one of claims 2 to 5, wherein the first planar wall (207) and the second planar wall (208) are parallel to the actuation axis (Y2).

7. A locking mechanism according to any preceding claim, wherein the positioning member (2) comprises a rolling element (203) arranged on the flexible blade (200), the rolling element (203) being configured to roll on the outer periphery (300) of the actuating lever (3).

8. A locking mechanism according to any preceding claim, wherein the flexible blade comprises a first bent fixing tab (201) and a second bent fixing tab (202), the first and second bent fixing tabs (201, 202) being bent at an angle of 90° from a first portion (210) of the flexible blade (200) and positioned axially on either side of said first portion (210) of the flexible blade (200).

9. The locking mechanism of claim 8, wherein the first bent fastening tab (201) is bent in a direction opposite to the second bent fastening tab (202).

10. A locking mechanism according to claim 8 or 9, wherein the first bent fixing tab (201) and the second bent fixing tab (202) are axially offset from each other in a direction parallel to the actuation axis (Y2).

11. Locking mechanism according to any one of claims 8 to 10, in which: • a first fixing means (205), in particular a centering pin, cooperates with the first folded fixing tab (201) to limit the movement of the positioning member (2) in a plane perpendicular (P) to the actuation axis (Y2); and • a second fixing means (206), in particular a screw, cooperates with the second folded fixing tab (202) to block the movement of the positioning member (2) along an axis parallel to the actuation axis (Y2).

12. Locking mechanism according to claim 11, in which the flexible blade (200) has a shape configured to leave free a passage along an axis parallel to the actuation axis (Y2) allowing the assembly of the first and second fixing means (205, 206).

13. A locking mechanism according to any preceding claim, wherein the outer periphery (300) of the actuating lever (3) is made up of surfaces parallel to the actuating axis (Y2).

14. A locking mechanism according to any preceding claim, wherein the flexible blade (200) is formed integrally from a strip of metallic material, in particular from a steel sheet.

15. A transmission system comprising a shaft equipped with at least one locking recess (45) and a locking mechanism according to any one of claims 1 to 14.

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