VEHICLE SEAT ADJUSTMENT MECHANISM, VEHICLE SEAT INCLUDING SUCH A MECHANISM, AND METHOD FOR ASSEMBLING SUCH A MECHANISM

Abstract

A vehicle seat (1) adjustment mechanism (6) comprising: A transmission housing (9), An eccentric gear (16) rotatably mounted on an eccentric element (15), A slide (19) comprising a first radial guide element (20) and a second radial guide element (21), the slide (19) functionally cooperating with at least one first counter-element (22) of the transmission housing (9) by means of the first radial guide element (20), the slide functionally cooperating with at least one second counter-element (24) of the eccentric gear (16) by means of the second radial guide element (21), wherein the transmission housing (9) has at least one protrusion (50) configured to enter into axial contact with at least one face (33) of the slide (19) to eliminate or limit axial play (J) between the slide (19) and the eccentric gear (16). Figure of The abbreviation: Figure 5

Description

Title of the invention: ADJUSTMENT MECHANISM FOR A VEHICLE SEAT, VEHICLE SEAT COMPRISING SUCH A MECHANISM AND METHOD FOR MOUNTING SUCH A MECHANISM MECHANISM Technical field

[0001] The present invention relates to adjustment mechanisms and seats of motor vehicle comprising such mechanisms. Prior art

[0002] It is known to use reduction mechanisms in particular in automobile seat adjustment systems, in particular seat raising systems, such mechanisms may comprise: - A transmission box, - An eccentric element driven in rotation around a longitudinal direction X by a drive member, - An eccentric gear wheel mounted in rotation on the eccentric element, - An output member comprising an internal toothed crown which cooperates with the eccentric toothed wheel by partial engagement of the teeth, - A slider comprising a first radial guide element and a second radial guide element, the slider functionally cooperating with at least one first counter-element of the transmission housing by means of the first radial guide element, the slider functionally cooperating with at least one second counter-element of the eccentric toothed wheel by means of the second radial guide element, the slider then describes a translational movement along the at least one first counter-element of the transmission housing, And in which the eccentric element, the eccentric toothed wheel, the output member as well as the slider form a stack along a longitudinal axis X mounted in the transmission housing around a connecting shaft.

[0003] Such eccentric systems are known and in particular described in documents US8936526, WO201705641, US11180064 or WO2019179934.

[0004] Such a mechanism makes it possible in particular to obtain a relatively large reduction ratio for a small footprint, which is advantageous for example in the field of vehicles, and more particularly in the automobile field.

[0005] It has however been noted by the inventors that the counter-elements which cooperate with the first radial guide can break prematurely for no apparent reason when transmitting high torques, for example in the event of an impact or sudden braking.

[0006] The present disclosure is intended to resolve the situation. Summary

[0007] According to the present disclosure, there is provided an adjustment mechanism for a vehicle seat comprising: - A transmission box, - An eccentric element driven in rotation around a longitudinal direction X by a drive member, - An eccentric gear wheel mounted in rotation on the eccentric element, - An output member comprising an internal toothed crown which cooperates with the eccentric toothed wheel by partial engagement of the teeth, - A slider comprising a first radial guide element and a second radial guide element, the slider functionally cooperating with at least one first counter-element of the transmission housing by means of the first radial guide element, the slider functionally cooperating with at least one second counter-element of the eccentric toothed wheel by means of the second radial guide element, the slider then describes a translational movement along the at least one first counter-element of the transmission housing, In which the eccentric element, the eccentric toothed wheel, the output member and the slider form a stack along a longitudinal axis X mounted in the transmission housing around a connecting shaft, and in which the transmission housing comprises at least one protuberance configured to come into axial contact with at least one face of the slider to cancel or limit axial play between the slider and the eccentric toothed wheel.

[0008] Such a mechanism makes it possible to control the axial play between the slider and the eccentric gear wheel. In addition, the solution provided is simple, economical, space-saving and reliable.

[0009] In particular, it may not require any additional parts, and is easy to adapt to existing mechanisms.

[0010] The features set out in the following paragraphs may, optionally, be implemented, independently of one another or in combination with one another:

[0011] According to an improvement, the transmission housing may comprise two parts configured to be assembled with each other by screws oriented in the axial direction X, and the at least one protuberance of the transmission housing is configured to deform plastically against at least one face of the slide when tightening the screws for assembling the two parts of the transmission housing. This eliminates the need for an additional step in assembling the mechanism. In addition, the fact that the protrusions can deform allows the manufacturing dispersion of the elements of the stack and the housing to be absorbed.

[0012] According to an improvement, the at least one protuberance measures 0.6 mm in its longitudinal direction X, and the transmission housing is dimensioned so that the at least one protuberance deforms by 0 to 0.6 mm in its longitudinal direction X.

[0013] According to an improvement, the at least one protuberance projects from one or more internal faces of the transmission housing in the axial direction X, and comprises a proximal end at the level of one or more internal faces of the transmission housing, and a distal end at the level of the at least one face of the slide, a section in a plane normal to the axial direction X of the at least one protuberance has a smaller surface at the level of its distal end than at the level of its proximal end, preferably 2 times smaller, even more preferably 5 times smaller. Such a thinned shape at its distal end allows the protuberance to ensure almost point contact on the slide and thus to facilitate its crushing.

[0014] According to an improvement, the surface area of ​​the section of each protuberance in a plane normal to the longitudinal direction X at its proximal end measures a maximum of 15mm2, preferably a maximum of 5mm2. Such a dimension makes it possible not to undesirably increase the force required for tightening the screws of the transmission housing which must also allow the plastic crushing of the protuberances.

[0015] According to an improvement, the transmission housing comprises four protuberances, and the slider comprises a central body, the first radial guide element comprising two opposite U-shaped extensions, each comprising two branches which form extensions of the body and a guide space between the two branches, the four protuberances are each positioned opposite each branch of the two extensions so as to maintain contact with the slider during its translational movement along the at least one first counter-element of the transmission housing. Such a configuration allows the four protuberances to maintain stable contact with the slider throughout its translational movement along the first counter-element of the transmission housing. In addition, the presence of four protuberances thus distributed makes it possible to avoid a “rolling” movement of the slider.

[0016] According to an improvement, the at least one protrusion is configured to limit the axial play between the slider and the eccentric toothed wheel to a value less than 0.8mm, preferably 0.2mm.

[0017] According to an improvement, the protrusions are made of plastic and are integral with one of the two parts of the transmission housing, preferably with the base body, to form a single-piece plastic assembly obtained by molding or injection. Such a design is simple and economical and makes it possible not to clutter the mechanism with additional parts.

[0018] According to an improvement, the slide is made of metal, preferably heat-treated, so as to increase its hardness and facilitate the crushing of the protuberances.

[0019] The present disclosure also relates to a method of mounting a mechanism according to the present disclosure, comprising the following steps: - Assembly of a stack comprising the eccentric element, the eccentric toothed wheel, the output member and the slide in the axial direction X around the connecting shaft, - Assembly of the stack and the connecting shaft in a first part of the transmission housing, - Mounting a second part of the transmission housing on the connecting shaft, - Tightening of screws in the axial direction X to assemble the two parts of the transmission housing, said tightening causing the plastic deformation or contact of the at least one protuberance against the at least one face of the slide and respectively the cancellation or limitation of the axial play between the slide and the eccentric toothed wheel to a value less than 0.2 mm.

[0020] According to one embodiment, the present disclosure also relates to an adjustment mechanism for a vehicle seat comprising: - A transmission housing, - An eccentric element driven in rotation around a longitudinal direction X by a drive member, - An eccentric gear wheel mounted for rotation on the eccentric element, - An output member comprising an internal toothed crown which cooperates with the eccentric gear wheel by partial engagement of the teeth, - A slider comprising a first radial guide element and a second radial guide element, the slider functionally cooperating with at least one first counter-element of the transmission housing by means of the first radial guide element, the slider functionally cooperating with at least one second counter-element of the eccentric toothed wheel by means of the second radial guide element, the slider then describes a translational movement along the at least one first counter-element of the transmission case, in which the eccentric element, the eccentric gear wheel, the output member and the slider form a stack along a longitudinal axis X mounted in the transmission housing around a connecting shaft, and in which the eccentric gear wheel comprises attachment means and the slider has openings, the attachment means and the openings being configured to cooperate with each other and to limit the axial play between the eccentric gear wheel and the slider.

[0021] According to an improvement of the previous embodiment, the means for attaching the eccentric toothed wheel comprises at least one riveting and the at least one opening passes through the slide between a front face and a rear face of the slide, the riveting comprises at least one stop surface to limit the relative axial translational movement between the eccentric toothed wheel and the slide.

[0022] According to an improvement, the at least one attachment means and the at least one opening are dimensioned so that the axial play between the eccentric wheel and the slider is kept less than 0.8 mm, preferably less than 0.2 mm.

[0023] According to an improvement, the at least one attachment means is integral with the at least one second counter-element of the eccentric toothed wheel and the at least one opening is the second radial guide element, the at least one attachment means, the at least one second counter-element and the eccentric toothed wheel forming a single-piece assembly made of metal, for example steel.

[0024] According to an improvement, the transmission housing comprises two parts configured to be assembled by screws oriented in the axial direction X.

[0025] The present disclosure further relates to a motor vehicle seat comprising at least one adjustment mechanism according to the present disclosure.

[0026] According to an improvement, the motor vehicle seat according to the present disclosure comprises a height-adjustable seat, the at least one adjustment mechanism forming all or part of a seat raising mechanism.

[0027] The present disclosure also relates to a method of mounting a mechanism according to the preceding embodiment, comprising the following steps: - Assembly of the eccentric toothed wheel and the slide by cooperation between the attachment means and the openings, - Assembly of a stack comprising: the eccentric element, the eccentric toothed wheel in cooperation with the slide, and the output member in the axial direction X around the connecting shaft, the axial clearance between the eccentric toothed wheel and the slide being kept less than 0.2 mm, - Assembly of the stack and the connecting shaft in a first part of the transmission housing, - Mounting a second part of the transmission housing on the shaft of connection, - Tightening the screws in the axial direction X to assemble the two parts of the transmission housing. Brief description of the drawings

[0028] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which: Fig.l

[0029] [Fig.l] shows a vehicle seat according to one embodiment. Fig. 2

[0030] [Fig.2] shows an axial stacking of the mechanism according to one embodiment. Fig. 3

[0031] [Fig.3] shows a YZ section of a mechanism according to one embodiment. Fig. 4

[0032] [Fig.4] shows a YZ section of a transmission housing according to a rea ​​mode lization. Fig. 5

[0033] [Fig.5] shows an XZ section of a mechanism according to one embodiment. Fig. 6

[0034] [Fig.6] shows a detail of the XZ section of [Fig.5]. Fig. 7

[0035] [Fig.7] shows a mechanism according to a second embodiment. Fig. 8

[0036] [Fig.8] shows a graph illustrating the correlation between the axial play and the value of the admissible torque. Fig. 9

[0037] [Fig.9] shows part of the parts of an axial stack of the mechanism according to a embodiment. Description of the embodiments

[0038] [Fig. 1] represents a motor vehicle seat 1 which comprises a backrest 3 carried by a seat 2 itself mounted on a floor P of the vehicle, for example by means of longitudinal slides 4. The backrest 3 is possibly surmounted by a headrest 5.

[0039] The seat 2 is connected to the slides 4 by means of an adjustment mechanism, for example a raising mechanism, known per se (not illustrated) which makes it possible to adjust the height of the seat 2. This raising mechanism is controlled by an adjustment mechanism 6, itself driven by an actuating means such as an electric motor 7 controlled remotely by the user and driving a drive member 8 in rotation around a vertical rotation axis Z.

[0040] As shown in Figures 2 to 6, the adjustment mechanism 6 comprises a transmission housing 9 forming a fixed support relative to the seat 2 of the seat 1. This transmission housing 9 may comprise at least two parts, for example a base body 91 as well as a flange 92 forming a cover.

[0041] The assembly of the flange 92 on the base body 91 can be carried out for example by means of screws 12, or any other technique involving a progressive bringing together of the two parts relative to each other.

[0042] As illustrated in the figures, the flange 92 is more particularly assembled in a fixed manner, on the base body 91 by means of four screws 12.

[0043] Referring to [Fig.2], the adjustment mechanism 6 comprises the drive member 8 driven in rotation by the electric motor 7 and provided with a helical screw.

[0044] This drive member 8 transmits the input force to the mechanism, the latter being composed of different parts stacked along the longitudinal axis X, otherwise called axial direction X.

[0045] Indeed, the drive member 8 is engaged with a control member 13 by means of an external toothed crown 14 of the control member 13 and makes it possible to drive the control member 13 in rotation on a connecting shaft 26, the connecting shaft 26 extending along a longitudinal axis of rotation X which is also the axis of rotation of the control member 13. The longitudinal axis of rotation X can be perpendicular to the vertical axis Z and transverse axis Y.

[0046] The control member 13 may have, near its axis of rotation, an eccentric element 15 projecting along the longitudinal axis of rotation X and on which an eccentric toothed wheel 16 is rotatably mounted.

[0047] The eccentric gear wheel 16 is mounted on the eccentric element 15 so as to be able to pivot freely.

[0048] The eccentric gear wheel 16 is received inside an internal toothed ring 17, illustrated in Figures 2 and 5, of an output member 18 mounted on, or forming part of, the connecting shaft 26.

[0049] The eccentric toothed wheel 16 has a circumference and a number of teeth smaller than that of the internal toothed crown 17 so as to engage in the latter to create a reduction ratio in a manner which will now be described.

[0050] The eccentric toothed wheel 16 is locked in rotation relative to the axis of rotation X by means of a slider 19.

[0051] To this end, the slider 19 comprises a first radial guide element 20 as well as a second radial guide element 21.

[0052] Reference is now made to [Fig. 3]. The first radial guide element 20 is adapted to cooperate with a first counter-element 22 of the transmission housing 9, for example arranged on the base body 91.

[0053] To this end, the slide 19 may comprise a central body 30, the first radial guide element 20 may comprise two opposite U-shaped extensions, each comprising two branches 31 which form extensions of the body 30 and a guide space 32 between the two branches 31, the two branches 31 being adapted to slide in or against the first counter-element 22.

[0054] Thus, by cooperation between the first counter-element 22 and the two branches 31 of the guide element 20, the slide 19 is locked in rotation along the longitudinal axis X relative to the transmission housing 9 and is guided in radial translation along an axis perpendicular to the axial direction X, for example along the vertical axis Z.

[0055] However, the counter-element 22 does not allow the axial translation of the slide to be blocked in the longitudinal direction X relative to the transmission housing 9, which is therefore free to translate as much as the functional play of the axial stacking of the different parts of the mechanism allows.

[0056] In short, the cooperation of the first radial guide element 20 with the first counter-element 22 therefore guides in translation along a radial direction Z and blocks in axial rotation and in translation along the transverse axis Y the slide 19 relative to the transmission housing 9, while leaving it free to translate along the longitudinal axis X.

[0057] The second radial guide element 21 is adapted to cooperate with a second counter-element 24 of the eccentric toothed wheel 16.

[0058] For this purpose, the second radial guide element 21 may comprise one or more openings adapted to slide against the second counter-element 24.

[0059] Thus, the eccentric toothed wheel 16 can only move in a radial translational movement, for example along the transverse axis Y relative to the slide 19.

[0060] The opening(s) may, for example, block the eccentric toothed wheel 16 in translation relative to the slide 19 along the vertical axis Z.

[0061] The eccentric toothed wheel 16 can also be locked in rotation about the axis of rotation X relative to the slide 19.

[0062] The eccentric toothed wheel 16 can, on the other hand, be free to slide relative to the slider 19 along the longitudinal axis X, as long as the functional clearance of the stacking of the parts allows it.

[0063] The cooperation of the second longitudinal guide element 21 with the second counter-element 24 therefore blocks in translation along the vertical axis Z and in rotation around the axis of rotation X the eccentric toothed wheel 16 relative to the slide 19, while leaving it free to slide along the transverse axis Y and along the longitudinal axis X.

[0064] In this way, the eccentric toothed wheel 16 can only move relative to the transmission housing 9 in circular translation along a plane YZ, and in particular is blocked in rotation about the axis of rotation X relative to the transmission housing 9 due to the cooperation of the first and second longitudinal guide elements 20, 21 of the slide 19 with the first and second counter-elements 22, 24 of the base body 91 of the transmission housing 9 and of the eccentric toothed wheel 16.

[0065] A complete circle of the eccentric gear 16 in the inner ring gear 17 angularly offsets the output member 18 relative to the transmission housing 9 by the difference in the number of teeth between the eccentric gear 16 and the inner ring gear, which generates the reduction ratio.

[0066] The control member 13, the eccentric toothed wheel 16, and the slider 19 can be made of metal or plastic.

[0067] The metal may in particular be heat-treated. The metal, optionally heat-treated, may be any metal used by a person skilled in the art in the fields of application described above and any heat treatment known to a person skilled in the art may be used for this purpose. The metal may be, for example, steel.

[0068] The heat treatment advantageously makes it possible to obtain sufficient hardness to resist wear resulting from the interaction between the different elements of the adjustment mechanism 6 over a desired period of use.

[0069] In the event of a significant impact, for example during a crash of the vehicle, a significant force, in particular a torque, is likely to be exerted and transmitted from the seat 1, and in particular from one end to the other, on the output member 18, the eccentric toothed wheel 16 and the slider 19, which may cause breakage of the second counter-elements 24 stressed locally by an excessively high concentration of shear stress by the slider 19.

[0070] To correct this effect, it was determined during research work carried out by the inventors that there is a correlation between the value of the maximum torque admissible by the counter-elements 24 and the value of the axial clearance J between the eccentric toothed wheel 16 which carries the second counter-elements 24 and the slide 19. The correlation between these two parameters is shown in [Fig.8].

[0071] Indeed, the greater the axial clearance J, the more the second counter-elements 24 are likely to break prematurely, that is to say at a lower torque value. It is therefore essential to limit as much as possible or even to cancel the axial clearance J between the eccentric toothed wheel 16 and the slide 19.

[0072] However, it is still necessary to maintain axial play between the other parts of the stack, this axial play being necessary for the kinematics of the parts. The challenge is therefore to cancel or limit only the axial play between the slide 19 and the toothed wheel 16. A tight assembly of the parts of the stack would not be possible, for example, since it would consequently block the rotation of the parts of the mechanism.

[0073] To this end, according to a first embodiment illustrated in [Fig.4] to 6, the transmission housing 9 may comprise at least one protuberance 50 configured to come into axial contact (along the longitudinal direction X) with at least one face 33 of the slider so as to cancel or limit the axial play J between the slider 19 and the eccentric toothed wheel 16.

[0074] The slide 19 may comprise two parallel faces, each perpendicular to the longitudinal axis X: one being a rear face 35, oriented towards the base body 91 of the transmission housing, the other, a front face 34 which is oriented towards the flange 92.

[0075] In a preferred embodiment, the at least one face 33 of the slide against which the at least one protrusion 50 comes into contact is the rear face of the slide 19.

[0076] In a particular variant, in the case for example where the slider comprises several faces, in particular rear faces, forming planes perpendicular to the longitudinal axis X more or less distant from the basic body of the transmission housing, the protuberances 50 can be of different sizes and dimensioned to come into contact with different faces.

[0077] In a preferred embodiment, the at least one protrusion 50 may protrude from an internal face 51 of the transmission housing in the axial direction X, the at least one protrusion extending from the internal face 51 to the at least one face 33, for example the rear face of the slider.

[0078] In a particular variant, in the same way as for the slide 19, the transmission housing may comprise several internal faces, for example forming planes perpendicular to the longitudinal axis X, more or less distant from the slide 19. The protuberances 50 may be arranged on different internal faces and extend to the rear face or faces of the slide 19.

[0079] The transmission housing 9 may comprise two parts 91 and 92, for example a base body 91, and a flange or a cover 92, configured to be assembled with each other by screws 12 oriented in the axial direction X, and in which the at least one protuberance 50 is configured to deform plastically against the at least one face 33 of the slide 19 when the screws 12 are tightened for the assembly of the two parts 91, 92 of the transmission housing.

[0080] Indeed, the two parts of the transmission housing 9 can be configured to be clamped against each other by gradually moving towards each other. This moving towards each other is a way of inducing the plastic deformation of the at least one protuberance 50 against the slide.

[0081] This deformation is useful to be able to absorb the differences in dimensions due to the dispersion of the manufacturing of the parts.

[0082] For example, in a case where the axial dimensions of the parts of the stack are all maximum, the stack may have a maximum total axial dimension chain. In this case given as an illustrative example, non-deformable protuberances could hinder the assembly of the assembly.

[0083] Conversely, in a case where the parts all have minimal axial dimensions, the stack could have a minimal total axial dimension. In this second illustrative example, once mounted, axial play could remain even with the use of protrusions, the stack possibly being too short along the longitudinal axis X to come into contact with the protrusions.

[0084] Thus, in a preferred embodiment, the protrusions 50, the parts of the stack and the transmission housing 9 can be sized so that, once the two parts 91, 92 of the housing are assembled: - In the case of a minimum dimension chain, the protrusions are in contact with the slide, with little or no deformation, the axial play being limited or cancelled, - In the case of a maximum dimension chain, the protrusions are in contact with the slide, the protrusions having deformed plastically by crushing against the slide to allow the assembly of the mechanism, the axial play being cancelled.

[0085] In an intermediate case in which the dimension chain is for example nominal, the protuberances may be capable of deforming plastically to allow assembly, the deformation naturally being of a lesser travel than that of the case of maximum dimension chain.

[0086] This deformable solution can in particular make it possible to cancel or limit the axial play between the eccentric toothed wheel 16 and the slider 19 in all cases provided for by the axial dispersion of the parts of the stack.

[0087] The at least one protuberance may extend in projection from the at least one internal face 51 from a proximal end 52, towards a distal end 53 located at the level of the at least one face 33 of the slide.

[0088] According to a preferred embodiment notably illustrated in [Fig.6], a section in a plane normal to the axial direction X of the at least one protuberance 50 has a surface area smaller at its distal end 53 than at its proximal end 52, preferably 2 times smaller, even more preferably 5 times smaller.

[0089] Such a dimension feature makes it possible to ensure almost punctual contact with the slide, and thus to facilitate the plastic deformation of the at least one pro tubercle, the force required for deformation being reduced by the size of the sectional area at the end.

[0090] The dimensions of the at least one protuberance 50 can be chosen according to the dispersion of the parts of the stack.

[0091] According to one embodiment, the at least one protuberance 50 measures between 2 and 5 mm in its longitudinal direction X, preferably 3 mm, and the transmission housing 9 is dimensioned so that the at least one protuberance deforms by 0 to 2 mm in its longitudinal direction X, preferably by 0 to 1 mm.

[0092] In one embodiment, the surface area of ​​the section of each protuberance 50 in a plane normal to the longitudinal direction X at its proximal end measures at most 15mm2, preferably at most 5mm2.

[0093] According to a preferred embodiment, the protuberances are cylindrical and / or conical in revolution, with a diameter at its proximal end less than or equal to 4.5 mm, preferably 2.5 mm. Such a shape of revolution facilitates the manufacture of the protuberances, in particular by molding.

[0094] The transmission housing may have at least one protrusion, or 2, 3, 4 or more.

[0095] According to a preferred embodiment, the transmission housing comprises four protrusions 50, this allows good load distribution and greater stability. In addition, such a hyperstatic arrangement is not problematic given the deformable nature of the protrusions.

[0096] The slider 19 may comprise a central body 30, the first radial guide element 20 comprising at least two extensions extending from opposite sides of the central body 30, each comprising a branch 31 which forms an extension of the body 30 configured to slide against the at least one first counter-element 22 of the transmission housing 9 to guide the slider in radial translation.

[0097] The at least one protuberance 50 can be positioned axially opposite the at least one extension so as to maintain contact with the slider 19 during its translational movement along the at least one first counter-element 22 of the transmission housing.

[0098] In a preferred embodiment, the transmission housing comprises 4 protuberances, the first radial guide element 20 of the slide 19 comprising two opposite U-shaped extensions, each comprising two branches 31 which form extensions of the body 30 and a guide space 32 between the two branches 31, the two branches being of rectangular section and comprising 4 parallel sides, the first counter-elements being grooves having a bottom surface and two parallel lateral surfaces, the four protuberances 50 are each positioned on the bottom surface of a first counter-element, axially opposite each branch

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105] 31 of the two extensions so as to maintain contact with the slide 19 during its translational movement along the at least one first counter-element 22 of the transmission housing 9. According to a particular embodiment, the at least one protrusion is configured to limit the axial play between the slider and the eccentric toothed wheel to a value less than 0.8 mm, preferably less than 0.2 mm, even more preferably less than 0.05 mm. The at least one protrusion may be one or more parts added to the transmission housing, for example glued, welded or fixed by means known to those skilled in the art. The at least one protrusion 50, the slider 19, the eccentric toothed wheel 16 as well as the transmission housing 9 may be made of metal and / or plastic. In a preferred embodiment, the at least one protrusion is integral with the transmission housing 9, preferably with the base body 91, to form a single-piece plastic assembly, obtained by molding or injection. In a preferred embodiment, the slider may be made of metal, preferably heat-treated. Such treatment known to those skilled in the art advantageously makes it possible to obtain sufficient hardness to extend the service life of the mechanism, but also to ensure that it is the protuberance 50 which deforms plastically, and not the transmission housing 9. The present disclosure also relates to a method of mounting a mechanism as described above, the method may comprise the following steps: - Assembly of a stack comprising the eccentric element 15, the eccentric toothed wheel 16, the output member 18 and the slider 19 in the axial direction X around the connecting shaft 26, - Mounting the stack and the connecting shaft 26 in a first part of the transmission housing 9, for example in the base body 91, - Mounting a second part of the transmission housing on the connecting shaft 26, for example, of the flange 92, - Tightening of screws 12 in the axial direction X to assemble the two parts 91, 92 of the transmission housing, said tightening causing the plastic deformation or the bringing into contact of the at least one protuberance 50 against the at least one face 33 of the slide 19 and respectively the cancellation or limitation of the axial play J between the slide 19 and the eccentric toothed wheel 16 to a value less than 0.8 mm, preferably less than 0.2 mm. According to a variant shown in [Fig.7], which may be an alternative to the first embodiment, the eccentric toothed wheel 16 and the slider 19 may comprise means for cooperating with each other, and cancelling or limiting the axial play J between both rooms.

[0106] The eccentric toothed wheel may comprise attachment means 60, and the slide 19 may comprise locking means 61, for example openings 61, the attachment and locking means being configured to cooperate with each other in order to limit the axial play J between the slide 19 and the eccentric toothed wheel 16.

[0107] According to a preferred embodiment, the attachment means 60 of the eccentric toothed wheel 16 may comprise at least one bulge, for example obtained by semi-cutting, for example by punching directly in the material of the eccentric toothed wheel 16, and the at least one opening may pass through the slide 19 between a front face 34 and a rear face 35 of the slide 19, the front and rear faces being able to be parallel to the longitudinal axis X, the bulge is configured to penetrate into the opening 61 and to then be crushed to form at least one stop surface 62, a riveting is then obtained configured to limit an axial translational movement between the two parts by means of the stop surface 62.

[0108] The abutment surface 62 of the riveting and the bulge are configured so as not to hinder the translation along the transverse axis Y of the eccentric toothed wheel 16 relative to the slide 19. The riveting only makes it possible to block the translation of the eccentric toothed wheel along the longitudinal axis X.

[0109] According to this variant, the attachment means 60 and locking means, for example the openings 61, are also configured to maintain an axial clearance between the slide 19 and the eccentric toothed wheel 16 at a value less than 0.8 mm, preferably less than 0.2 mm, even more preferably less than 0.05 mm.

[0110] The hooking and locking means 60, for example the openings 61, can each comprising one or more parts attached to the slide 19 and / or to the eccentric toothed wheel 16, these parts can be glued, welded or fixed by means known to those skilled in the art.

[0111] In a preferred embodiment, the at least one attachment means 60 is integral with the at least one second counter-element 24 of the eccentric toothed wheel 16 and the at least one opening 61 is the second radial guide element 21 of the eccentric toothed wheel, the at least one attachment means 61, the at least one second counter-element 24 and the eccentric toothed wheel 16 form a single-piece assembly made of metal, for example steel.

[0112] The present disclosure further relates to a method of mounting a mechanism as described above, the method may comprise the following steps: - Assembly of the eccentric toothed wheel 16 and the slider 19 by cooperation between the hooking means 60 and the locking means, for example the openings 61, - Assembly of a stack comprising: the eccentric element 15, the wheel eccentric toothed wheel 16 in cooperation with the slide 19, and the output member 18 in the axial direction X around the connecting shaft 26, the axial clearance between the eccentric toothed wheel 16 and the slide 19 being kept less than 0.2 mm, - Mounting of the stack and the connecting shaft 26 in a first part, for example in a lower body 91 of the transmission housing 9, - Mounting of a second part, for example a flange 92, of the transmission housing on the connecting shaft 26, - Tightening of screws 12 in the axial direction X to assemble the two parts 91, 92 of the transmission housing.

[0113] The present disclosure also relates to a vehicle seat 1, for example an automobile, which may comprise at least one adjustment mechanism 6 as described above.

[0114] According to a preferred embodiment, the vehicle seat 1 may comprise an adjustable seat 2, for example in height, the at least one adjustment mechanism 6 forming all or part of a mechanism for adjusting the seat, for example for raising the seat. Industrial application

[0115] These technical solutions can be applied in particular in the automotive field, but can also be applied to any mechanism requiring a reduction ratio, for example on board any type of vehicle or machine. List of reference signs

[0116]

[0117] - 1: Vehicle seat - 2: Adjustable seat - 3: File - 4: Slides - 5: Headrest - 6: Adjustment mechanism - 7: Electric motor - 8: Drive organ - 9: Transmission box - 12: Screws - 13: Control organ - 14: External toothed crown - 15: Eccentric element - 16: Eccentric gear wheel - 17: Internal toothed crown - 18: Output organ - 19: Slider - 20: First radial guide element - 21: Second radial guide element - 22: First counter-element - 24: Second counter-element - 26: Connecting shaft - 30: Central body - 31: Branches - 32: Guidance space - 33: Face of the slide - 34: Front face - 35: Back face - 50: Protuberance - 51: Internal face - 52: Proximal end - 53: Distal end - 60: Means of attachment - 61: Blocking means - 62: Stop surface - 91: Basic body - 92: Flaccid - J: Axial clearance between the eccentric gear wheel and the slide - P: Floor

Claims

Claims

1. Adjustment mechanism (6) for a vehicle seat (1) comprising: - A transmission box (9), - An eccentric element (15) driven in rotation around a longitudinal direction X by a drive member (8), - An eccentric toothed wheel (16) mounted in rotation on the eccentric element (15), - An output member (18) comprising an internal toothed crown (17) which cooperates with the eccentric toothed wheel (16) by partial engagement of the teeth, - A slider (19) comprising a first radial guide element (20) and a second radial guide element (21), the slider (19) functionally cooperating with at least one first counter-element (22) of the transmission housing (9) by means of the first radial guide element (20), the slider functionally cooperating with at least one second counter-element (24) of the eccentric toothed wheel (16) by means of the second radial guide element (21), the slider (19) then describes a translational movement along the at least one first counter-element (22) of the transmission housing, in which the eccentric element (15), the eccentric toothed wheel (16), the output member (18) and the slider (19) form a stack along a longitudinal axis X mounted in the transmission housing (9) around a connecting shaft (26), and in which the transmission housing (9) comprises at least one protuberance (50) configured to come into axial contact with the at least one face (33) of the slider (19) to cancel or limit an axial clearance (J) between the slider (19) and the eccentric toothed wheel (16).

2. Mechanism according to claim 1, in which the transmission housing (9) comprises two parts (91, 92) configured to be assembled with each other by screws (12) oriented in the axial direction X, and in which the at least one protuberance (50) is configured to deform plastically against the at least one face of the slide when tightening the screws (12) for the assembly of the two parts (91, 92) of the transmission housing.

3. Mechanism according to claim 2, wherein the at least one protrusion (50) measures 0.6 mm in its longitudinal direction X, and the transmission housing (9) is dimensioned so that the at least one protrusion deforms from 0 to 0.6 m in its longitudinal direction X.

4. Mechanism according to one of claims 1 to 3, in which the at least one protuberance (50) projects from one or more internal faces (51) of the transmission housing in the axial direction X, and comprises a proximal end (52) at the level of one or more internal faces (51) of the transmission housing, and a distal end (53) at the level of the at least one face (33) of the slide, a section in a plane normal to the axial direction X of the at least one protuberance (50) has a surface area which is smaller at its distal end (53) than at its proximal end (52), preferably 2 times smaller, even more preferably 5 times smaller.

5. Mechanism according to any one of the preceding claims, in which the transmission housing comprises four protrusions (50), and the slider (19) comprises a central body (30), the first radial guide element (20) comprising two opposite U-shaped extensions, each comprising two branches (31) which form extensions of the body (30) and a guide space (32) between the two branches (31), the four protrusions (50) are each positioned opposite each branch (31) of the two extensions so as to maintain contact with the slider (19) during its translational movement along the at least one first counter-element (22) of the transmission housing.

6. Adjustment mechanism according to any one of the preceding claims in combination with claim 2, wherein the protrusions (50) are made of plastic and are integral with one of the two parts (91, 92) of the transmission housing, preferably with the base body (91), to form a single-piece plastic assembly obtained by molding or injection.

7. Method of assembling a mechanism according to any one of the preceding claims, comprising the following steps: - Assembling a stack comprising the eccentric element (15), the eccentric toothed wheel (16), the output member (18) and the slider (19) in the axial direction X around the connecting shaft (26), - Mounting the stack and the connecting shaft (26) in a first part (91) of the transmission housing (9), - Mounting a second part (92) of the transmission housing on the connecting shaft (26), - Tightening screws (12) in the axial direction X to assemble the two parts (91, 92) of the transmission housing, said tightening causing the plastic deformation or the contacting of the at least one protuberance (50) against the at least one face (33) of the slide (19) and respectively the cancellation or the limitation of the axial play (J) between the slide (19) and the eccentric toothed wheel (16) to a value less than 0.2 mm.

8. Adjustment mechanism (6) for a vehicle seat (1) comprising: - A transmission housing (9), - An eccentric element (15) driven in rotation about a longitudinal direction X by a drive member (8), - An eccentric toothed wheel (16) mounted in rotation on the eccentric element (15), - An output member (18) comprising an internal toothed ring (17) which cooperates with the eccentric toothed wheel (16) by partial engagement of the teeth, - A slider (19) comprising a first radial guide element (20) and a second radial guide element (21), the slider (19) cooperating functionally with at least a first counter-element (22) of the transmission housing (9) by means of the first radial guide element (20), the slider cooperating functionally with at least a second counter-element (24) of the eccentric toothed wheel (16) by means of the second radial guide element (21),the slide (19) then describes a translational movement along the at least one first counter-element (22) of the transmission housing, in which the eccentric element (15), the eccentric toothed wheel (16), the output member (18) as well as the slide (19) form an em-, stacking along a longitudinal axis X mounted in the transmission housing (9) around a connecting shaft (26), and in which the eccentric toothed wheel (16) comprises hooking means (60) and the slider has openings (61), the hooking means and the openings being configured to cooperate with each other and to limit the axial play (J) between the eccentric toothed wheel (16) and the slider (19).

9. Motor vehicle seat (1) comprising at least one adjustment mechanism (6) according to one of claims 1 to 6 or according to claim 8.

10. Motor vehicle seat (1) according to the preceding claim, comprising a seat (2) adjustable in height, the at least one adjustment mechanism (6) forming all or part of a mechanism for raising the seat.

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