FR2956623A1 - Motor vehicle seat joint for use in angular adjusting device, has control plate comprising elastic legs exerting radial force on drive shaft for reducing radial clearance between drive shaft and control component - Google Patents

Abstract

The joint has a control component (11) with a cam (2) pressing locking elements toward an exterior in a locked position, and a control plate (1) moving the locking elements toward an interior in an unlocked position. A drive shaft (3) receives the control component in an axial recess (13), and is connected in rotation to the control component around a main joint axis (Y). The control plate comprises elastic legs e.g. elastic tabs (52), exerting radial force on the drive shaft for reducing radial clearance between the drive shaft and the control component. An independent claim is also included for an angular adjusting device comprising a connection bar provided with external ribs.

Description

Angular adjustment device for vehicle seat

The present invention relates to articulations and angular adjustment devices for vehicle seat, and particularly relates to the seat back joints with discontinuous adjustment. More specifically, the subject of the invention is a motor vehicle seat joint allowing an angular adjustment of a first seat element with respect to a second seat element around a main articulation axis, and comprising: first and second articulation flanges, intended to be integrally bonded respectively to said first and second seat elements, - a control member adapted to move locking elements adapted to immobilize the first hinge flange relative to the second flange of articulation, this control member comprising a cam adapted to push the locking elements outwards in the locked position and a control plate adapted to move said locking elements inwards in the unlocked position, - a control shaft, received in axial recesses of the first and second hinge flanges, and received in an axial recess of the control member, and integral in rotation with said control member around the main axis. Such a seat joint of the document FR2908090 is known; however, in this document, the attachment of the control shaft relative to the control member requires the use of specific tools such as welding tools. The present invention is intended to improve the seat joints, to avoid having to use specific tools to assemble the control shaft relative to the control member.

To this end, according to the invention, a seat hinge of the type in question is characterized in that said control plate comprises at least two elastic tabs exerting a radial force, directed towards the main axis, on the shaft of control, to reduce the radial clearance between the control shaft and the control member. In various embodiments of the invention, one or more of the following arrangements may also be used: the articulation further comprises an axial holding device by clipping the shaft control device on said control member, adapted to prevent relative movement between said control shaft and said control member in the direction of the main axis; said resilient clipping lugs comprise a free end located opposite a first shoulder of said control shaft, said first shoulder immobilizing said control shaft in a first axial direction; said control shaft comprises a second shoulder resting on a bearing surface of said control member, immobilizing the latter in a second axial direction, opposite to the first axial direction; the control shaft comprises a plurality of external, axially extending and radially outwardly extending grooves, and wherein said control member comprises a plurality of radially inwardly extending projecting teeth received substantially without set respectively in said outer grooves to immobilize in rotation about the main axis said control member and said control shaft; the control plate comprises three resilient clipping tongues, distributed equally

3 circumferential; - Said control shaft further comprises at least one axial recess extending axially and adapted to receive a connecting bar, said connecting bar being adapted to control a second joint. The invention also relates to an angular device for adjusting a vehicle seat comprising a first articulation as described above, the control member of the first articulation forming the first control member, the control shaft of the first articulation forming first control shaft, said adjustment device further comprising a second articulation comprising: third and fourth articulation flanges, intended to be integrally bonded respectively to said second and first seat elements, a second control member adapted to moving second locking members adapted to immobilize the third hinge flange relative to the fourth hinge flange; - a second drive shaft received in axial recesses of the third and fourth hinge flanges and received in a second hinge flange; axial recess of said second control member, and rotate the second control member about the main axis. In various embodiments of the invention, one or more of the following arrangements may be used in addition: the connecting bar comprises a first end 30 comprising a plurality of axial external ribs projecting radially outwardly, and the first control shaft has a plurality of axially extending internal grooves complementary to said three external ribs and adapted to receive without play the first end of the connecting bar by

4 fitting. The invention also relates to a vehicle seat comprising a seat, a backrest and at least one hinge as described above or an angular adjustment device as defined above. Other aspects, objects and advantages of the invention will appear on reading the following description of an embodiment of the invention, given by way of non-limiting example. The invention will also be better understood with reference to the accompanying drawings, in which: FIG. 1 is a general view of a vehicle seat equipped with a hinge according to the invention, FIG. 2 is a front view of an angular adjustment device comprising first and second articulations according to the invention; FIG. 3 is an exploded perspective view of an angular adjustment device comprising the first and second articulations of FIG. 2; FIG. 4 is a partial section of the first Figure 5 shows a portion of the first hinge in Figure 2; Figure 6 is a partial sectional view of the second hinge; articulation, on an enlarged scale, according to the section plane VI-VI of FIG. 2, in the unlocked state; FIG. 7 is a section of the first articulation, on an enlarged scale, along the section plane VII; VII of FIG. 4; FIG. 8 is an axial sectional view of the control shaft; FIG. 9 is an end view of the control shaft; FIG. 10 is a view similar to FIG. Fig. 3 for a second embodiment of the invention; and Fig. 11 is a view similar to Fig. 5 for the second hinge in the second embodiment of the invention. In the various figures, the same references denote identical or similar elements. FIG. 1 shows a motor vehicle seat 100 comprising a backrest 102 which is pivotally mounted on a seat 101 around a horizontal transverse pivot axis Y, also called a hinge axis, the seat 101 being mounted on the floor of the vehicle 105 if necessary via slides 104. De plus in the region of the hinge axis 103, there is provided a control handle 8 which allows a user to adjust the angular position of the backrest by relative to the seat, and more generally a first seat element relative to a second seat element. The pivoting of the backrest 102 is possible thanks to an angular adjustment device, represented in FIGS. 2 and 3, comprising a first hinge 10 and a second hinge 20, respectively on each side of the seat, operable in a synchronized manner by the control handle. 8 or any other actuating device, said control handle 8 being arbitrarily on the side of the first articulation 10.

These first and second joints 10, 20, are adapted to block the pivoting of the backrest 102 relative to the seat 101 under normal use, and are also adapted to allow a rotational movement of the backrest when the user requests the control handle 8. As represented in FIGS. 2 to 4, the first hinge 10 firstly comprises first and second flanges 81, 82 fixed respectively to the backrest frame 102 and to the frame reinforcement 101. These two flanges 81, 82 may have forms substantially

6 circularly and be interconnected by a metal outer ring crimped 85 thereby defining an interior space which contains a locking device comprising one or more locking elements 12 each having an external toothing 12a. The second flange 82 has a peripheral annular zone 87, having a toothed surface 88 oriented radially inwards and located opposite external teeth 12a of the locking elements 12.

Each locking element 12 is radially displaceable in guides 14 belonging to the first flange 81, between a locked position (FIG. 4) in which the toothing 12a of the locking element 12 engages with the toothed surface 88 belonging to the second flange 82 and an unlocked position (FIG. 6) in which the locking element 12 is moved radially inwards so that its toothing 12a does not cooperate with the toothed surface 88 of the second flange 82, and thus releases the rotation of the second flange 82 relative to the first flange 81. The first hinge 10 further comprises a control member 11 pivotally mounted about the Y axis and adapted to move the locking elements 12 between their locked position and their unlocked position. This control member 11 comprises a control plate 1 and a cam 2, and is resiliently biased by one or more springs 19 to a locking position in which the cam 2 displaces the locking element 12 preferably corresponding radially to the outside in locked position (Figure 4). This control member 11 can be moved in rotation by the actuation of the handle 8 to an unlocking position (FIG. 6) in which said control plate 1 drives the locking element 12 to move it preferably radially towards the inside

7 to the unlocked position. Said control plate 1 is preferably metallic and has the general shape of a flat disc of constant thickness whose normal and axis coincide with the main axis of articulation Y. Said control plate 1 comprises: - a recess central 13 delimited by an inner edge 61 from which extend elastic tongues 52 extending obliquely towards the center 10 relative to the main axis Y, - a series of three holes 63 distributed on a circle and able to receiving complementary pins 64 arranged similarly on the surface of the cam 2 coming into contact with the control plate 1, 15 - at least one bean-shaped recess, and in the example shown three identical recesses 16 distributed on a close circle a circular outer edge 65 of the control plate 1, each recess 16 having a ramp 15 inclined relative to a circle centered on the axis Y. Said cam 2 is preferably metallic and extends as a thick disc perpendicular to the main axis Y, and comprises: - a central recess 13a defining an inner edge 68 from which projections 18 in the form of teeth 18 extend radially towards the main axis Y, - three inclined faces 67 forming a cam on the peripheral zone of the cam and adapted to push the locking element 12 towards the outside, - the pins 64 already mentioned. As shown particularly in FIG. 6, for the unlocked position, the displacement of the locking member 12 radially inwardly is forced by the ramp 15 of the recess 16 of the control plate 1

8 in which is engaged a pin 17 belonging to the locking element 12; likewise, for the locked position, as shown in particular in FIG. 4, the displacement of the locking element 12 radially outwards is forced by the inclined face 67 forming a cam of the cam 2. Said cam 2 and said control plate 1 are assembled together to form the control member 11, this being done by inserting said pins 64 in said holes 63, this insertion being preferably performed without play and in force so that said cam 2 and said control plate 1 are perfectly secured. Furthermore, the first hinge 10 further comprises a control shaft 3, adapted to drive the control member 11, in particular when the user requests the control handle 8. This control shaft 3, shown in detail in particular in Figures 8 and 9, is a plastic molded part, which extends along the main axis Y between a first end 92 of square section on which is fitted the control handle 8, and a second end 93, located at the opposite. Starting from the first end 92, the control shaft 3 comprises: - a square section with a throat 55 adapted to receive a circlip secured to the control handle 8 to hold it firmly in place, - a portion of square section 56 a circular section 54, smaller than the square section portion 56, a drive portion 57 of generally cylindrical shape of revolution centered on the Y axis, and comprising three external grooves 38 extending according to the axial direction and open radially outwardly, each of said outer grooves 38 being delimited according to

9 the axial direction by: - a first shoulder 53 adjacent the second end 93 and oriented towards the first end. - A second shoulder 51 adjacent to said circular section 54 and oriented towards the second end 93, each tooth 18 of the cam 2 is received without play in the corresponding outer groove 38 and rests on said second shoulder 51; the drive of the cam 2 by the control shaft 3 and therefore of the control member 11 by the control shaft 3 is thus realized. In addition, the control shaft 3 may comprise an axial recess 31 extending from the second end 93 towards the first end 92, able to receive, in three internal cylindrical bearing surfaces 33 and axial internal grooves 32, an element of synchronization with the second articulation 20, which will be described later. As shown in particular in FIGS. 5 and 7, when the control shaft 3 is installed in its position in the first articulation 10, the second shoulder 51 bears on a bearing surface 69 of the cam 2, and the first shoulder 53 is supported on a free end 52a of each elastic tongue 52. In addition, at the time of insertion of the control shaft 3 inside the control member 11, the resilient tongues 52 are pushed radially towards outside. They return a little inward as soon as the free end 52a has passed the first shoulder 53 at the end of the insertion stroke. Due to the residual stress, these resilient tongues 52 exert an inwardly directed radial force on the control shaft 3 to reduce the radial clearance between said control shaft 3 and the control member 11. The first articulation 10 thus defined is obtained by a simplified method. Indeed, first of all, the

The first joint is preassembled by means in particular of its first and second flanges 81, 82, its control member 11 and its elastic return 19, the locking elements 12, and the crimped crown 85. The control shaft 3 can be inserted without specific tools by introducing it axially from the side where the control handle 8 is located. In the insertion movement, the second end 93 and the driving portion 57 pass successively through the axial recess 13c of the first flange 81, then the axial recess 13a of the cam 2, then the axial recess 13 of the control plate, then the axial recess 13d of the second flange 82, then finally spread radially outwardly the resilient tongues 52. This insertion movement is completed when the second shoulder 51 abuts against the bearing surface 69 on the cam 2, this bearing 69 being able to be achieved by the teeth 18 already mentioned. Just before the end of the insertion movement, the first shoulder 53 exceeds the free end 52a of the elastic tongues, and said free end 52a is then returned to its rest position closer to the Y axis, and is then in position. directly opposite the first shoulder 53 and whereby any withdrawal movement of the control shaft 3 is prevented and a residual pressure directed radially inwards is exerted by the resilient tongues on the control shaft 3. The first shoulder 53, the second shoulder 51 and the resilient tongues 52 of the control plate 1 thus constitute an axial holding device 5 by clipping the control shaft 3 onto said control member 11, adapted to prevent relative movement. between said control shaft and said control member 11 in the direction of the main axis Y. It should be noted that without departing from the scope of the invention, any other clipping yen filling

11 a similar function. The angular adjustment device according to the invention may comprise a second hinge 20, symmetrical image of the first hinge 10 relative to the Y axis and located on the opposite side of the seat relative to the first hinge 10; this second articulation 20 is similar or identical to the first articulation, except for certain aspects which are detailed below. As represented in FIGS. 2, 3 and 6, the second articulation 20 comprises: third and fourth flanges 83, 84 similar to the first and second flanges 81, 82 and respectively fixed to the backrest frame 102 and to the armature of the seat 101, supplemented by a crimped peripheral ring 86, - a second control member 21, comprising a control plate 21a similar to the control plate 1 of the first articulation 10 and a cam 21b similar to the first cam 2 the first hinge 10, the control plate 21a comprising resilient tongues 52 similar to the already described resilient tongues 52 of the control plate 1; second locking elements 22 similar to the locking elements 12 of the first hinge 10, a second control shaft 4, also called a control sleeve 4, situated in axial recesses 13a, 23 of the second control member 21; recall (not shown and similar to the spring 19 of the first hinge 10) adapted to return the control member 21 to the locking position. The internal operation of the second hinge 20 is similar to that of the first hinge 10 and will not be described again in detail. The element

12 which differs in the second hinge 20 is the control sleeve 4 which will be described below. To be able to be synchronously controlled by the handle 8, the control members 11,21 of the first and second joints 10,20 are interconnected by a connecting rod 7, which extends along the axis of articulation Y between the first hinge 10 and the second hinge 20. The connecting bar 7 is preferably a molded piece of plastic material, and comprises (see Figure 3). a first end portion 71 adapted to be engaged in the axial recess 31 of the control shaft 3, an intermediate portion 76 substantially cylindrical in revolution, and a second end portion 72 similar to the first portion; end portion 71, and received in the control sleeve 4. The first end portion 71 comprises three outer ribs 73, distributed on the periphery between outer cylindrical bearing surfaces 74, each outer rib 73 extending along the direction axial. Each external rib 73 is received in one of the internal grooves 32 formed in the axial recess 31 of the control shaft 3.

The control sleeve 4 is preferably a piece of plastic material which comprises: a circular portion 41, a driving portion 42 having external grooves 48 similar or identical with respect to the external grooves 38 already described, said external grooves 48 having first and second shoulders similar to the first and second shoulders 53, 51 of the outer grooves 38 already described, - an axial recess 43 passing axially through the control sleeve 4, and having

13 internal grooves 32, similar to the internal grooves 32 already described in the axial recess 31 of the control shaft 3. Like the first end portion 71, the second end portion 72 comprises three external ribs 73 distributed on the periphery between outer cylindrical bearing surfaces 74. Each external rib 73 is received in the corresponding internal groove 32 formed in said axial recess 43 of the control sleeve 4.

Like the control shaft 3, the control sleeve 4 is inserted into position without the use of specific tools. The elastic tongues 52 are erased during insertion and return somewhat to their state of rest at the end of movement when the control sleeve 4 comes into abutment on a bearing surface of the second control member 21. A residual pressure directed radially towards the The inside is exerted by the resilient tongues 52 on the control shaft 4 to reduce the radial clearance between said control shaft 4 and the control member 21. It should be noted that a closure piece (not shown ) or a stop (not shown) located on the outer face of the sleeve 4 prevents the connecting rod 7 from moving in the direction of the main axis Y.

In addition, Figures 10 and 11 illustrate a second embodiment of the invention, which differs from the first mode only by the elements which are explained below, the other elements being similar or identical.

The parts that differ are: the first control shaft 3 ', the connecting bar 7', the second control shaft 4 ', the first cam 2' and the second cam 21c. The first control shaft 3 'comprises: a square section 55, 56 similar to that already described,

14 - a drive portion 57 'having a triangular general section, and comprising a notch 58 adapted to receive the elastic tongue, said notch being delimited by the first and second shoulders 51,53, - a section fitting portion 37 generally cylindrical of revolution and whose surface comprises grooves 39 oriented parallel to the main axis Y, this fitting portion 37 ending in a chamfer 36.

The second control shaft 4 'comprises: - a fitting portion 47 of cylindrical general section of revolution and whose surface comprises grooves 49 oriented parallel to the main axis Y, this fitting portion 47 ending in a chamfer 46, - a driving portion 42 'having a triangular general section, - a conical end 49 terminating the driving portion 42' opposite the fitting portion 47. The first cam 2 'has a central section 95 which has a shape complementary to the shape of the section of the driving portion 57 'of the first control shaft 3', so as to create a cooperation without significant play in rotation about the main axis Y. The first cam 2 'can thus be rotated by the first control shaft 3' and vice versa. The second cam 21c has a central section 94 which has a shape complementary to the shape of the section of the driving portion 42 'of the second control shaft 4', so as to create a cooperation without significant play in rotation around the l main axis Y. The second cam 21c can thus be rotated by the second control shaft 4 'and vice versa.

The connecting bar 7 'is a simple tubular piece,

15 cylindrical of revolution, having an inner diameter very slightly less than the outer diameter of the fitting portions 37, 47. Due to the presence of the chamfers 36, 46 on their ends, the first and second control shafts 3,4, can be force-fitted in the connecting bar 7 '. The presence of the streaks 39,49 on the fitting portions 37,47 subsequently prevent any relative rotation of the first and second control shafts 3,4 around the main axis Y. Once this fit is achieved, it is possible to proceed insertion of this assembly from the side of the first articulation 10 (arrow 'K' in Figure 10). At first, the second control shaft 4 'passes through the recesses 13, 13a of the first control member 11 by discarding the resilient tongues 52, but without being retained axially. Threading is then continued until the second control shaft 4 'comes into contact with the control member 21, the second articulation 20.

At this point, the ramps of the tapered tip 49 allow the elastic tongues 52 to be pulled apart, although they are caught backwards and the insertion can continue. The insertion movement comes to an end when the first shoulder 51 arrives on the stop 69 of the first control member 11. At this stage, the elastic tongues 52 of the first control plate 1 are immobilized along the main axis Y between the first and second shoulders 51,53 as explained above. In this position, the drive portions 57 'and 42' are respectively located at the right of the central sections 95 and 94 of the first and second control members 11,21, which allows a simultaneous drive of the first and second control members 11 , 21 from the operating handle 8 via the assembly comprising the connecting bar 7 'and the first and second control shafts 3', 4 '.

Advantageously according to the invention, it is thus possible first of all to prepare the assembly comprising the connecting bar 7 'and the first and second control shafts 3', 4 ', then to insert this assembly without specific tools from the side intended to to receive the operating handle 8. It should be noted that the connecting rod 7, 7 'may have some torsional flexibility so that a small angular offset between the locked rest positions of the first and second control members 11 , 21 can be caught. It should be noted that, as regards the two embodiments, the number of resilient tongues 52 may be different from three, one can equally well realize the invention with two elastic tongues 52, as well as with four or more elastic tongues. . It should be noted that, with respect to the first embodiment, the width of the elastic tongue 52 may be wider, for example close to the transverse width of the outer groove 38, which makes it possible to ensure the rotational drive of the control plate and therefore the control member in addition to or in replacement of the direct drive of the cam 2 by the teeth 18.

Claims (10)

REVENDICATIONS1. Motor vehicle seat joint (10; 20) for angular adjustment of a first seat member relative to a second seat member about a principal axis (Y) of articulation, and comprising: - first and second second hinge flanges (81; 83,82; 84) intended to be integrally connected respectively to said first and second seat elements; - a control member (11; 21) adapted to move locking elements (12) adapted to immobilizing the first hinge flange (81; 83) with respect to the second hinge flange (82; 84), this control member (11; 21) comprising a cam (2,21b; 2 ', 21c) adapted to pushing the locking elements (12) outwards in the locked position and a control plate (1; 21a) adapted to move said locking elements (12) inwards in the unlocked position, - a control shaft (3 , 4; 3 ', 4'), received in axial recesses (13c, 1c) 3d; 23) first and second hinge flanges, and received in an axial recess (13; 23) of the control member (11; 21), and rotatably integral with said control member (11; 21) around of the main axis (Y), characterized in that said control plate (1; 21a) comprises at least two resilient tabs (52) exerting a radial force, directed towards the main axis (Y), on the control shaft (3; 4) for reducing the radial clearance between the control shaft (3; 4) and the control member (11; 21). 2. Articulation according to claim 1, further comprising an axial holding device (5) by clipping the control shaft (3) on said control member 18 (11), adapted to prevent relative movement between said shaft of control and said control member (11) in the direction of the main axis (Y). 3. Articulation according to claim 2, wherein said resilient tabs (52) clipping comprise a free end (52a) located vis-à-vis a first shoulder (53) of said control shaft, said first shoulder immobilizing said control shaft (3) in a first axial direction. 4. Articulation according to claim 3, wherein said control shaft (3) comprises a second shoulder (51) supported on a bearing surface (69) of said control member (11) immobilizing it in a second axial direction. opposite to the first axial direction. Articulation according to any one of the preceding claims, wherein the control shaft (3; 4) comprises a plurality of axially extending and radially outwardly extending outer grooves (38), and wherein said control member comprises a plurality of teeth (18) projecting radially inwardly received substantially without clearance respectively in said outer grooves (38) for immobilizing in rotation about the main axis said control member (11; 21) and said control shaft (3; 4). 6. Articulation according to any one of the preceding claims, wherein the control plate (1) comprises three elastic tongues (52) clipping, equitably distributed circumferentially. 7. Articulation according to any one of the preceding claims, wherein said control shaft (3) further comprises at least one axial recess (31) extending axially and adapted to receive a connecting bar (7), said bar link (7) being adapted to control a second hinge (20). An apparatus for angular adjustment of a vehicle seat comprising a first articulation (10) according to any one of the preceding claims, the control member (11) of the first articulation (10) forming the first control member (11), the control shaft of the first articulation forming first control shaft (3), said adjusting device further comprising a second articulation (20) comprising: - third and fourth articulation flanges (83, 84) intended to be integrally connected respectively to said second and first seat members, - a second control member (21) adapted to move second locking members (22) adapted to immobilize the third hinge flange (83) relative to the fourth hinge flange (84), - a second drive shaft (4), received in axial recesses (23) of the third and fourth hinge flanges, and received in an axial recess ( 23) of said second control member (21), and rotatably connected to the second control member (21) about the main axis (Y), the adjusting device further comprising a connecting bar (7) extending along the main axis (Y), intended to be rotatably connected to said first control shaft (3) and said second control shaft (4). An adjusting device according to claim 8, wherein the connecting bar (7) comprises a first end (71) having a plurality of external axial ribs (73) protruding radially outwardly, and wherein the first shaft control unit comprises a plurality of axially extending internal grooves (32) complementary to said three external ribs (73) adapted to receive without play the first end of the connecting rod by fitting. Vehicle seat comprising at least one hinge (10) according to any one of claims 1 to 7, or comprising an angular adjustment device according to any one of claims 8 to 9.