FR2989643A1 - FOLDING-BACK VEHICLE SEAT COMPRISING A HEADREST WITH ADJUSTABLE LATERAL LEGS - Google Patents

Abstract

The present invention relates to a motor vehicle seat comprising a seat (20) and a backrest (10) pivotable about a first transverse axis (D) located at the rear of the seat (20) between a raised position and a position folded against said seat (20), said seat comprising a headrest (30) mounted at the top of said backrest (10) and which has a central portion (40) and two lateral flanges (50) pivotable relative to said central portion (40) between an alignment position in which they are arranged in the extension of said central portion (40), and an extended position in which they protrude from said central portion (40) in the direction of said seat (20), said seat also comprising return means (55) capable of automatically causing the return of said side cheeks (50) to alignment position when said backrest (10) is rotated from said raised position to said positionfolded.

Description

Title of the Invention Folding-back vehicle seat having a headrest with adjustable side cheeks.

FIELD OF THE INVENTION The present invention relates generally to a motor vehicle seat whose upper part of the backrest is provided with a headrest, and more particularly to a seat with folding backrest generally fitted to the rear seats of a vehicle. such vehicle.

BACKGROUND OF THE INVENTION This type of seat comprises a seat slidably mounted on the floor of the vehicle by means of slides and a backrest that can pivot about a transverse axis located at the rear of the seat between a raised position adapted to receive the back of a user, and a folded position in which it bears against this seat. The document EP-A-1,500,550 for example describes such a folding seat whose seat is articulated on the backrest along a second transverse axis offset from the first transverse axis so as to cause when folding the backrest, a lowering of the seat and a translation of the latter forwardly relative to the movable rails slides. This movement of the seat makes it possible to increase the angle of folding of the backrest, so that when folded completely against the seat, the headrest of this backrest is pressed against the front of the seat while its rear face is found in a substantially horizontal plane. However, when the back of such a folding seat is provided with a headrest having side cheeks, the latter can, when in deployed configuration, come into contact with the front part of the seat before the folder has reached its folded position. The user must therefore exert greater pressure on the backrest to achieve this folded position in which the side cheeks compress specific areas of the front part of the seat. This repeated compression tends after a while, to generate aesthetically detrimental aspect defects. In some cases, the lateral cheeks can even completely prevent the backrest from reaching the folded position, so that the residual angle of inclination between the backrest and the horizontal is greater, resulting in a reduction in the available storage volume. OBJECT AND SUMMARY OF THE INVENTION The present invention therefore aims to overcome these drawbacks. It proposes for this purpose a motor vehicle seat comprising a seat and a backrest that can pivot about a first transverse axis located at the rear of the vehicle. seated between a raised position adapted to receive the back of a user, and a folded position in which it bears against said seat, said seat further comprising a headrest mounted at the top of said backrest, characterized in that said headrest comprises a central portion and two lateral cheeks pivotable relative to said central portion between an alignment position in which they are arranged in the extension of said central portion, and an extended position in which they project vis-à- screw of said central portion towards said seat, and in that said seat comprises return means capable of automatically causing the return said side cheeks in alignment position when said backrest is rotated from said raised position to said folded position. The return means that includes the seat and cooperate with the articulated lateral cheeks of the headrest by automatically bringing them into the plane of the central portion during the pivoting of the folder to its folded position. The seat according to the invention therefore ensures that no side cheek remains in the deployed position when the backrest is folded against the seat.

Therefore, the user does not have to manually exert any additional pressure on the folder to make it reach its folded position. Moreover, by avoiding that the lateral cheeks exert repeated compressive forces on certain areas of the front part of the seat, the seat according to the invention makes it possible to preserve the padding covering the seat of the eventual appearance of appearance defects. According to preferred features of the invention, taken alone or in combination: - said return means comprise two non-extensible traction cables, the first ends of which are each rigidly fixed to a said corresponding cheek and whose second ends are each connected to a member of said seat, so that the pivoting of said seat from said raised position to said folded position causes the tensioning of said cables, the latter then exerting on said cheeks a tensile force causing their return to alignment position; said second ends of said cables are connected to a first said member of said seat which moves in translation towards the front with respect to said first transverse axis during the pivoting of said backrest from said raised position to said folded position; said second ends of said cables are connected to a second said member of said seat which remains fixed with respect to said first transverse axis during the pivoting of said backrest from said raised position to said folded position; said return means comprise two tensioning cams fixed on an element of said backrest and whose free ends are each traversed by a said corresponding cable, said cams being arranged so as to extend vertically opposite said backing member; head when said folder occupies said raised position, and horizontally opposite said seat when said folder occupies said folded position; said free ends of said cams each have an eyelet for the passage of a said corresponding cable; said second ends of said cables are each connected to a said member of said seat by means of a corresponding compensation spring; each said cable extends horizontally from its said first end to a respective return pulley mounted in rotation on an axis perpendicular to said central portion of the headrest; Said central portion of the headrest comprises at least one hollow rod ensuring the support of said headrest vis-à-vis the upper part of said backrest, and in which runs at least one said cable; said central portion of said headrest comprises a single said hollow rod in which said two cables travel; - said central portion of said headrest comprises two said hollow rods in each of which chimney a said corresponding cable; each of said hollow rods has a lateral inlet bore for a said cable, said bore being situated opposite a said respective pulley; said seat comprises a frame having a first part comprising two underbody supports disposed on each of the sides of said seat and articulated to said backrest according to said first transverse axis, and a second part covered by a padding and articulated to said backrest along a second transverse axis offset from said first transverse axis so that when said backrest is folded, said second portion of said armature and said padding are displaced in translation forwardly with respect to said first portion of said armature and said first transverse axis; said second ends of said cables are each connected to the same transverse tube of said second part of said armature; and / or - said second ends of said cables are each connected to a respective said underbody support of said first part of said armature. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and other advantages thereof will appear more clearly in the light of the description which follows, data, given below by way of illustration but without limitation, with reference to the accompanying drawings. , in which: - Figure 1 is a schematic representation of a side view of a folding seat according to a preferred embodiment of the invention, the seat having its backrest in the raised position; - Figure 2 is a representation of a profile view of the seat of Figure 1, the seat having its backrest in the folded position against the seat; - Figure 3 is a schematic representation of a rear view, on a larger scale, of the headrest and the upper part of the seat back of Figures 1 and 2; - Figure 4 is a schematic representation of a side view of a folding seat according to a variant of the invention, the seat having its backrest in the raised position; and - Figure 5 is a representation of a profile view of the seat of Figure 4, the seat having its backrest in the folded position against the seat. DETAILED DESCRIPTION OF THE EMBODIMENT FIGS. 1 to 3 illustrate a preferred embodiment of a motor vehicle seat 1 according to the present invention. It should be noted that this motor vehicle seat can be of any rank, for example front seat or rear seat of rank 2 or 3.

This seat comprises a backrest 10 and a seat 20, each comprising a padding 11, 21, and a rigid armature 12, 22. The two lower lateral ends 13 of the frame 12 of the backrest are interconnected by a transverse tube 14 of which the axis D constitutes a first pivot axis for the backrest 10, the latter can thus be pivoted between a raised working position, able to receive the back of a passenger, and a folded position against the seat 20. The armature 22 of the seat 20 comprises a first portion 22A constituted by two underbody supports 23 disposed on each of the sides of the seat 1, and articulated to the backrest 10 along the axis D via their rear ends surrounding the transverse tube 14. Each support 23 is mounted on a movable rail 24A of a respective slideway 24 also having a fixed rail 24B along which the movable rail 24A is slidable.

Rolling means, not shown, are interposed between the movable rails 24A and fixed 24B. The slides 24 also each comprise a means for immobilizing the movable rail 24A in the corresponding fixed rail 24B. These immobilization means, not shown in the figures, may for example be constituted by movable bolts adapted to engage in recesses made longitudinally in the rails and spaced regularly. The immobilizing means are controlled by means of a control member disposed under the seat 20, for example at the level of the base support 23.

The second portion 22B of the frame 22 of the seat 20 covered by the padding 21 is hinged to the backrest 10 along a second transverse axis C, and via two seat brackets 25 in the form of a hockey stick. The main branches 25A of these brackets 25 constitute the lateral flanges of the frame 22 of the seat 20, and their free ends are interconnected at a transverse axis B. The second branches 25B of these brackets 25, substantially perpendicular to the main branches 25A, extend upwards protruding from the rear part of the upper face of the padding 21, and their free ends are connected with pivoting freedom around a transverse tube 15 of the frame 12 of the backrest 10 whose axis C thus constitutes a second pivot axis.

This second axis C is offset relative to the first axis D so that, during the folding of the backrest 10, the second portion 22B of the frame 22 of the seat 20 and the padding 21 are moved in translation forward by relative to the first portion 22A of the frame 22 and the movable rail 24A. This translation causes the movement of at least one support member of the seat formed by a U-shaped front tube 26, each U-rod being connected to a respective side of the seat 20 so as to be able to pivot about a transverse tube 27 of the frame 22 of this seat 20, the axis B constitutes a third pivot axis. The base of this U is articulated in its middle around a front foot 28 so as to be pivotable about a tube axis / foot A transverse, this front foot 28 is also attached to the floor of the vehicle. The seat 1 also comprises a headrest 30 mounted at the top of the backrest 10, and which extends upwardly. This headrest 30 comprises a central portion 40 and two lateral cheeks 50 each comprising a padding 41, 51 surrounding a rigid frame 42, 52. The rigid frame 42 of the central portion 40 comprises a hollow metal frame 43 in the form of U inverted whose two parallel rods 44 provide support for the headrest 30 vis-à-vis the upper part of the backrest 10, these rods 44 through holes provided for this purpose in rigid guides 16 mounted in the part This rigid frame 40 also comprises a plate 45 which is fastened by snapping on the two rods 44 of the frame 43. The two lateral ends of this plate 45 are articulated along two parallel axes E to the rods 44. , with two rigid wings 53 which constitute the frames 52 of the lateral cheeks 50, so that these cheeks can pivot relative to the central portion 40 between an alignment position in which they are arranged in the extension of this central portion 40, and an extended position in which they project vis-à-vis the central portion 40 and in the direction 35 of the seat 20 of the seat 1.

According to the invention, the seat 1 also comprises return means adapted to allow to automatically cause the return of the cheeks 50 of the headrest 30 in the alignment position, when the folder 10 is folded down on the seat 20.

These return means comprise two non-extensible flexible metal cables 55, a first end 56 is fixed rigidly on a corresponding flange 53 of a cheek 50. Each cable 55 extends horizontally from this first end 56 towards the central portion 40 then passes into a return pulley 45A rotatably mounted on an axis F extending from the plate 45 and perpendicular to this central portion 40. Each of the cables 55 then enters a corresponding rod 44 of the U-frame 43 via a lateral drilling 44A located next to a pulley 45A, then runs inside this rod 44 and towards the backrest 10. The return pulleys 45A can support the cables 55 and to prevent them from coming in. contact with the lower edges of the lateral holes 44A and thus undergo significant shearing efforts that may cause their deterioration.

At the outlet of the rods 44, the two cables 55 continue their path parallel to each other towards the lower end of the backrest 10. These two cables 55 then cross the plane of the seat 20 slightly behind the transverse tube 14 on which are welded two guide elements not shown in the figures. These guide elements which have on their respective rear face, a groove along which the corresponding cable is slidable, prevent the cables 55 from rubbing directly against the metal tube 14 which could eventually deteriorate.

After passing through the plane of the seat 20, the two cables 55 advance towards the front of the seat 20 to the transverse tube 27 to which their second ends 57 are each connected by means of a compensation spring 58 respective (see Figure 2).

The cables 55 are also guided along their length by not shown eyelets which keep them applied to the frames 12, 22 of the backrest 10 and the seat 20. To move the backrest 10 from its raised working position, able to receiving the back of a passenger, in its folded position against the seat 20, the user must actuate a folding control handle not shown in the figures. This action causes the seat 1 to be shifted backwards by sliding the seat 20 over the guides 24 followed by a second step of pivoting the backrest 10 about its transverse hinge axis D to bring it into contact with the seat 20. This pivoting causes a collapse of the seat 20 and a translation thereof (and in particular the transverse tube 27) forward with respect to the hinge axis D. It is understood easily that this translation tube 27 which are connected to the second ends 57 of the cables 55, will stretch these cables and increase their voltage, so that a tensile force is exerted on the first ends 56 of these cables attached to the reinforcements Lateral cheeks 50. This tensile force thus causes these cheeks 50 to pivot about the axes E, the latter returning to their alignment position in which they are arranged in the extension of the portion 40 of the headrest 30. Once the cheeks 50 in their alignment position, the tensile forces exerted on the cables 55 due to the continued movement of folding the backrest 10 against the seat 20, are then absorbed by the two compensation springs 58 which stretch. When the backrest 10 reaches its folded position shown in FIG. 2 and in which it is applied against the seat 20, it can be seen that the lateral cheeks 50 which occupy their alignment position do not come into contact with the front part. The seat 1 'illustrated in Figures 4 and 5, is similar to the seat 1 except that the biasing means in the alignment position of the cheeks of the headrest are shaped differently. In the continuation and on the drawings, one kept the same references for the identical elements and with a premium for the similar elements. The return means comprise two cams 59 for tensioning which are welded to the transverse tube 14, so that they extend vertically opposite the headrest 30 when the backrest 10 'occupies its seat. raised position shown in Figure 4, and they extend horizontally opposite the seat 20 when the folder 10 'is in its folded position shown in Figure 5. At the exit of the rods 44 of the frame hollow metal 43 in the form of U, the two cables 55'A continue their path parallel to each other in the direction of the lower end of the backrest 10 '. These two cables 55 'then cross the plane of the seat 20 slightly behind the transverse tube 14 and then enter two eyelets located at the free ends of the two cams 59 and not shown in the figures. At the exit of these eyelets, each of the two cables 55 'continues its forward path to a corresponding underbody support 23 to which their second ends 57' are each connected by means of a respective compensation spring 58. In the same way as for the seat 1, the actuation of the folding control handle causes a translation of the seat 1 'to the rear by sliding the seat 20 on the rails 24 followed by a second pivoting step 10 'back around its axis 25 transverse articulation D to bring it in contact with the seat 20. The substructures 23 remaining fixed relative to the hinge axis D during the pivoting of the folder 10 ', the second ends 57' of the cables 55 'are therefore not driven in translation forwards during the pivoting of the backrest 10' as is the case on the seat 1. This pivoting of the backrest 10 'also causes a rotation transverse tube 14 on which are fixed the two cams 59.

It is easy to understand that the rotation of these cams 59 will tension the cables 55 'and then increase their tension, so that a traction force is exerted on the first ends 56' of these same cables fixed to the frames of the lateral cheeks 50, this effort causing the return of the cheeks 50 to their alignment position. Once the lateral cheeks 50 in their alignment position, the tensile forces exerted on the cables 55 'due to the continued movement of folding the backrest 10' against the seat 20, are then absorbed by the two springs of compensation 58 'stretching.

According to another variant not shown, the support of the headrest vis-à-vis the upper part of the backrest is provided by a single central hollow rod traversed by the two cables that comprise the return means of the support- head. According to yet another variant not shown, the seat has no compensation spring, the length of the cables being determined so that the return of the cheeks in their alignment position occurs just before the folder reaches its folded position. Of course, the present invention is not limited to the embodiments described and shown, but encompasses any other embodiment.

Claims (15)

REVENDICATIONS1. Motor vehicle seat comprising a seat (20) and a backrest (10; 10 ') pivotable about a first transverse axis (D) situated at the rear of the seat (20) between a raised position able to receive the back of a user, and a folded position in which it bears against said seat (20), said seat further comprising a headrest (30) mounted at the top of said backrest (10; 10 '), characterized in that said headrest (30) comprises a central portion (40) and two lateral flanges (50) pivotable relative to said central portion (40) between an alignment position in which they are disposed in line with said central portion (40), and an extended position in which they protrude from said central portion (40) towards said seat (20), and in that said seat comprises return means (55; ', 59) capable of automatically causing the return of said lateral cheeks (50) in alignment position when said folder (10; 10 ') is rotated from said raised position to said folded position. 2. Motor vehicle seat according to claim 1, characterized in that said biasing means comprise two non-extensible traction cables (55; 55 '), the first ends (56; 56') of which are each rigidly fixed to a said cheek (50) corresponding and whose second ends (57; 57 ') are each connected to a member (27; 23) of said seat (20), so that the pivoting of said seat (10; 10') of said raised position in said folded position results in the tensioning of said cables (55; 55 '), the latter then exerting on said cheeks (50) a tensile force causing their return to alignment position. 3. motor vehicle seat according to claim 2, characterized in that said second ends (57) of said cables (55) are connected to a first said member (27) of said seat (20) which moves in translation towards the front to said first axetransversal (D) during pivoting said backrest (10) from said raised position to said folded position. 4. Motor vehicle seat according to claim 2, characterized in that said second ends (57 ') of said cables (55') are connected to a second said member (23) of said seat (20) which remains fixed relative said first transverse axis (D) during the pivoting of said backrest (10 ') from said raised position to said folded position. 5. Motor vehicle seat according to claim 4, characterized in that said return means comprise two cams (59) for tensioning fixed on a member (14) of said folder (10 ') and whose free ends are each traversed by a said corresponding cable (55 '), said cams (59) being arranged to extend vertically opposite said headrest (30) when said backrest (10') occupies said raised position, and horizontally opposite said seat (20) when said backrest (10 ') occupies said folded position. 6. Motor vehicle seat according to claim 5, characterized in that said free ends of said cams (59) 20 each have an eyelet for the passage of a said cable (55 ') corresponding. 7. Motor vehicle seat according to one of claims 2 to 6, characterized in that said second ends (57; 57 ') of said cables (55; 55') are each connected to a said member (27; 23) said seat (20) by means of a corresponding compensation spring (58; 58 '). 8. Motor vehicle seat according to one of claims 2 to 7, characterized in that each said cable (55; 55 ') extends horizontally from its said first end (56; 56') to a pulley return member (45A) rotatably mounted on an axis (F) perpendicular to said central portion (40) of the headrest (30). 9. Motor vehicle seat according to one of claims 2 to 8, characterized in that said central portion (40) of the headrest (30) comprises at least one hollow rod (44) providing support for said headrest (30) vis-à-vis the upper part of said backrest (10, 10 '), and wherein runs at least one said cable (55; 55'). 10. Motor vehicle seat according to claim 9, characterized in that said central portion (40) of said headrest (30) comprises a single said hollow rod in which runs both said cables (55; 55 '). 11. Motor vehicle seat according to claim 9, characterized in that said central portion (40) of said headrest (30) comprises two said hollow rods (44) in each of which chimney a said corresponding cable (55; 55 ') . 12. Motor vehicle seat according to claims 8 and 11, characterized in that each of said hollow rods (44) has an inlet side bore (44A) for a said cable (55; 55 '), said bore (44A). ) being located opposite a said pulley (45A) respectively. 13. Motor vehicle seat according to one of claims 1 to 12, characterized in that said seat (20) comprises an armature (22) having a first portion (22A) comprising two substructure supports (23) arranged on each of sides of said seat and articulated to said backrest (10; 10 ') along said first transverse axis (D), and a second portion (22B) covered by a padding (21) and articulated to said backrest along a second transverse axis (C) offset by to said first transverse axis (D) so that when said backrest (10; 10 ') is folded, said second portion (22B) of said armature (22) and said padding (21) are displaced in translation forwards by relative to said first portion (22A) of said armature (22B) and said first transverse axis (D). 14. Motor vehicle seat according to claims 2 and 13, characterized in that said second ends (57) of said cables (55) are each connected to a same transverse tube (27) of said second portion (22B) of said frame (22). 15. Motor vehicle seat according to claims 2 and 13, characterized in that said second ends (57 ') of said cables (55') are each connected to a said base support (23) of said respective first portion (22A ) of said armature (22).