FR2988047A1 - Seat for car, has shell comprising frame interdependent of rigid metal external frame of backrest and movable central part that is adapted to move in translation opposite of frame according to transverse axis to backrest - Google Patents

Abstract

The seat has a backrest (40) whose back face includes a shell (50). The shell comprises a frame interdependent of a rigid metal external frame (41) of the backrest and a movable central part. The central part is adapted to move in translation opposite of the frame according to a transverse axis to the backrest. A driving unit is adapted to move in translation to the central part in forward direction when the seat slides toward the backrest of a floor of a vehicle. The driving unit includes metal cables (73, 74) that are rolled up around a pulley (71).

Description

HULL SEAT FOR MOTOR VEHICLE. FIELD OF THE INVENTION The present invention relates to the field of seats for motor vehicles, and in particular to those whose back has a rear face constituted by a shell. BACKGROUND OF THE INVENTION The seats of motor vehicles proposed by manufacturers include, more and more frequently, seats, in particular front seats, whose backrest comprises a rear face constituted by a shell, generally made of plastic, optionally filled with a fabric that can be matched to the decoration of the cabin.

The presence of such a shell improves the finish and style of the seat, and contributes to an increase in the level of quality felt by the user. This type of seat, known in particular from the French application FR 2 793 455, however has the disadvantage of reducing the livability of the vehicle. Indeed, it is common when a large front passenger recedes his seat to have more legroom, the rear face of this seat comes into contact with the rear passenger's knees. Because of the rigidity of the hull, this configuration is particularly uncomfortable and the front passenger is forced to re-advance partially his seat. OBJECT AND SUMMARY OF THE INVENTION The present invention therefore aims to provide such a seat shell 30 providing better livability to the vehicle. It proposes for this purpose, a seat intended to be slidably mounted on the floor of a motor vehicle and having a backrest whose rear face is constituted by a shell; said seat being characterized in that said shell comprises a frame secured to the frame of said folder and a movable central portion, said movable central portion being able to move in translation vis-à-vis said frame along an axis transverse to said folder. The fact that the hull has a movable central portion that can move in translation makes it possible to vary the habitability for the passengers located at the rear of the seat. Thus, in the case where the seat is set in its most retracted position, this movable central portion can be moved in translation forward to allow the rear passenger to benefit from greater space in the legs. Conversely, when the seat is set in a more advanced position, the central part of the hull can be arranged further back in a visually more aesthetic position, without however hindering the rear passenger since the space in the legs remains sufficient.

According to preferred features of the seat, taken alone or in combination: - said seat comprises means adapted to drive in translation forwardly said movable central portion when sliding towards the rear of the floor of said vehicle; said drive means are provided for passing said shell with an alignment configuration in which the rear faces of said frame and of said mobile central part are situated in the same plane, to a comfort configuration in which the rear face said movable central portion is located at the front of the rear face of said frame; said drive means comprise a pulley rotatably mounted on an axis and at least one cable, passing through at least one gland tab secured to said movable central part, and whose ends are fixed respectively to said frame and said axis of rotation; said cable winding around said pulley while being stretched when said seat slides towards the rear of the floor, so that said movable central portion is driven in translation forwards by said grommet tongue; - Said seat is slidably mounted on said floor by means of two rails each having at least one movable element integral with said seat and adapted to slide axially along a corresponding rail; said drive means further comprise a rack arranged along a said rail to which it is fixed; said pulley being secured to a said movable member slidable along said rail, and having a notched flange cooperating with said rack so that said pulley is rotated when said seat slides on the floor; said drive means comprise two said cables, each of them having a portion extending horizontally over the width of said shell between a first pair of tongues fixed on the legs of said frame, each said horizontal portion of a said cable; traversing a second pair of tongues secured to said movable central portion of the shell; said cables wind around said pulley while stretching when said seat slides towards the rear of the floor, so that said movable central part is driven in translation forwards by said second pairs of tongues; the four tabs forming the first and second pairs of tongues of each said cable are aligned when said shell occupies its comfort configuration; each said cable comprises a first generally vertical portion extending from said pulley to a corresponding angular gear, at right angle, forcing it to fork horizontally; said seat comprises elastic return means permanently biasing said shell towards said alignment configuration; said elastic return means comprise at least one helical compression spring; said return means comprise four said springs, each said spring being disposed between a transverse bar integral with said frame and said central movable part of the shell, close to each of its four corners; and / or - said seat comprises two so-called transverse bars from each of which extend two said springs.

Brief description of the drawings The description of the invention will now be continued by the detailed description of an exemplary embodiment, given below by way of illustration but without limitation, with reference to the appended drawings, in which: FIG. a view from above and in perspective of the frame of a seat according to the invention whose shell occupies its comfort configuration; FIG. 2 represents an enlarged view and at another angle of a part of the elements constituting the drive means in translation of the movable central part of the shell; - Figure 3 shows an enlarged view and at an angle still different from the pulley and the rack that includes these drive means in translation; and FIG. 4 represents a view similar to that of FIG. 1, but in which only the shell, the drive means and the elastic return means are shown in order to facilitate understanding of the invention. DETAILED DESCRIPTION OF THE EMBODIMENT The front seat frame 1 shown in FIG. 1 is intended to be mounted on a floor of a motor vehicle (not shown). It is conventionally constituted by a seat 20 and a backrest 40 articulated between them. The seat 20 comprises two lateral flanges 21, 22 of sheet steel located facing one another and between which extend two transverse cylindrical tubes 23 and front 24 rear, also formed of steel sheet. The two flanges 21, 22 are also slidably mounted on the floor of the vehicle by means of two slides 25, 26.

Each slide 25, 26 has two movable elements 25A, 26A and rear 25B, 26B integral with a corresponding flange 21, 22; each movable member 25A, 26A, 25B, 26B being slidable axially along a fixed rail 25C, 26C mounted on the floor of the vehicle.

The slides 25, 26 also each comprise a means for immobilizing the movable elements 25A, 26A, 25B, 26B in the corresponding rail 25C, 26C. This immobilization means, not shown in the figures, may for example be constituted by a movable bolt adapted to engage in recesses made longitudinally in the rail 25C, 26C and spaced regularly. The immobilization means are controlled by means of a spreader 27 disposed under the nose 28 of the seat 20, as shown in FIG. 1. This spreader 27 consists of a metal rod made of steel or another material rigid having similar properties, has a profile reminding a U whose two branches would be spaced apart so as to form an angle of about 135 ° with the base of the U. The two cylindrical tubes 23, 24 of the seat 20 support a sheet elastic, not shown in the figures for better visibility of the invention, which is conventionally made of metal son extending between the two tubes 23, 24. These son are properly tensioned while maintaining a certain elasticity giving them a relative flexibility so that the quilted pad of the seat that surrounds the seat 20 is fixed and held against and inside thereof, providing the necessary support comfort. The nose 28 of the seat 20 consists of a continuous wire 33 extending between the two front ends of the two flanges 21, 22.

Just like the son forming the elastic sheet of the seat 20, the wire 33 has a succession of changes of direction at 90 °, also giving it a profile similar to that of a square-wave signal. To ensure the attachment of the nose 28 on the seat 20, each of the two ends of the wire 33 is fixed by welding on the inner face of a corresponding flange 21, 22, at its front end. On the other hand, the two rear transverse portions of this wire 33 are also fixed by welding to the transverse tube before 23 of the seat 20.

The backrest 40 comprises a rigid metal outer frame 41 in the shape of an inverted U and a rigid plastic shell 50 fixed to the frame 41 and constituting the rear face of this backrest 40. The lower ends of the two legs 42 and 43 of the frame 41 are articulated to the flanges 21, 22 of the seat 20 via a transverse cylindrical bar 45, so as to allow the tilting of the backrest 40 relative to the seat 20. In a conventional manner, a multitude of son transverse metal, not shown in the figures, are fixed on the frame 41 and distributed in superposed layers one above the other. These webs are suitably stretched while retaining a degree of elasticity giving them relative flexibility so that the quilted seat pad surrounding the backrest is secured and held against and within the backing, providing support comfort. necessary. The hull 50 will now be described in more detail with reference to FIG. 4. This hull consists of a generally rectangular fixed frame 51 and a movable central part 52, obtained by molding from a plastic material. The uprights 51A, 51B and the upper cross member 51C of the frame 51 are rigidly attached to the metal frame 41. The movable central portion 52 which is generally planar, has a generally rectangular shape with rounded corners. It is articulated to the frame 41 of the backrest 40 by means of elastic return means 60 and by translation drive means 70 which will now be described in detail in support of Figures 1 to 4. The elastic means restoring comprise two upper metal flat bars 61 and lower 62 which extend transversely between the two legs 42, 43 of the metal frame 41 of the back 40 and whose ends are welded to the inner face of these legs (Figure 1). They also comprise four compression coil springs 63, 64, 65, 66. The springs 63, 64 extend transversely between the upper bar 61 and the inner face 52A of the movable central portion 52. More specifically, a first end of the spring 63 (respectively 64) is fixed, for example by welding, to the upper bar 61 while the other end is fixed on the central portion 52 near one (respectively other) of its two upper corners. The springs 65, 66 extend transversely between the lower bar 62 and the inner face 52A of the central portion 52. More specifically, a first end of the spring 65 (respectively 66) is fixed, for example by welding, to the lower bar 62 while the other end is fixed on the central portion 52 near one (respectively the other) of its two lower corners. The translation drive means 70 comprise a toothed pulley 71 adapted to cooperate with a rack 72, two wire ropes 73, 74, guide elements 75, 76, 77, 78, 79 and grommet tabs 80, 81. , 82, 83, 84, 85, 86, 87. The pulley 71 is located at the movable member 25B of the right slide 25. It comprises a toothed flange 71A and a hub 71B integral with each other and traversed by an axis of rotation 71C whose opposite end to the flange 71A is rigidly connected, for example by welding, to a bracket fastening 71D-shaped bracket. As illustrated in FIG. 2, the fixing lug 71D is fixed by welding to the movable element 25B, so that the axis of rotation 71C is oriented transversely to the two slides 25, 26. The rack 72 is itself arranged along the rear portion of the inner edge of the fixed rail 25 to which it is welded. In Figure 3, it may be noted that the hub 71B has an axial slot 71E opening on the axis of rotation 71D.

This slot 71E is crossed by the two metal cables 73, 74, each of them having one of its ends which is fixed rigidly, for example by welding, on the axis of rotation 71C. From this axis 71C, the two cables 73, 74 extend first parallel to each other and in a generally vertical direction. More specifically, these two cables 73,74 begin by crossing the plane of the seat 20 slightly behind the transverse cylinder 24 on which is welded a metal guide 75. This guide element 75 which has on its rear face, two vertical grooves parallel along which the two cables 73, 74 are slidable, prevents them from rubbing directly against the metal cylinder 24 which could eventually deteriorate. After crossing the plane of the seat 20, the two cables 73, 74 run parallel along the right leg 42 of the frame 41, and up to about one third of its height (Figure 1). So that they do not come into contact with the cylindrical bar 45 of this frame 41, these two cables 73, 74 pass through an angle gear 76. This forms an angle facing the hull 50 and preferably comprised between 135 and 160 °. At one third of the height of the frame 51, the paths of the two cables separate. The cable 74 passes through a second right angled reference 78 which forces it to fork horizontally and towards the left leg 43 of the frame 41 (Figure 4). It will thus run along the shell 50 over its entire width, passing successively through three cable-pass tabs 82, 86, 87 until it reaches the level of the left-hand upright 51B of the frame 51 where its second end is welded to a fourth metal tab 83. The four tabs 82, 83, 86, 87 extend from the inner side of the shell 50 and transversely to the plane thereof. More specifically, the tabs 82 and 83 are formed of a metallic material and respectively welded to the right leg 42 and left 43 of the metal frame 41 of the back 40; while tabs 86 and 87, integrally molded with the movable central portion 52 of the shell 50, are located near the two side edges of this central portion 52. The cable 73 continues its path along the right leg 42 of the frame 41, through a guide 77 welded against this leg 42 (Figure 1) and to prevent the cable 73 strolls and interferes with other elements of the folder 40 not shown in the figures.

When this cable 73 reaches about two thirds of the height of the right leg 42, it passes through a third angular reference angle 79 which forces it to fork horizontally and towards the left leg 43 of the frame 41. It goes thus along the shell 50 over its entire width by successively passing through three metal cable tabs 80, 84, 85 until it reaches the level of the left leg 51B of the frame 51 where its second end is welded to a fourth tongue 81. The four metal tabs 80, 81, 84, 85 extend from the inner side of the shell 50 and transversely to the plane thereof. More specifically, the tabs 80 and 81 are respectively welded to the right leg 42 and left 43 of the metal frame 41 of the folder 40; while the tabs 84 and 85, molded with the movable central portion 52 of the shell 50, are located near the two lateral edges of this central portion 52.

We will now describe in detail the configurations that occupy the shell 50 according to the position of the armature 1 of the seat. When this armature 1 is set in the forward stop position (as shown in Figures 2 and 3); the pulley 71, mechanically connected to the rear movable member 25B, is located in front of the rack 72. In this position of the frame 1, the threads 73, 74 are entirely unrolled with respect to the hub 71C (FIG. ) so that the latter are not under tension and therefore exert no effort on the movable central portion 52 of the hull 50.

The latter is therefore only subjected to the restoring force exerted permanently against its inner face 52A by the four compression coil springs 63, 64, 65, 66. The latter which is oriented transversely to the backrest 40, pushes the movable central portion 52 of the hull 50 which is driven in translation backwards until it comes to occupy an alignment configuration. In this configuration, the rear faces of the fixed frame 51 and the mobile central portion 52 are located in the same plane, which improves the visual perception of passengers about the style and quality of finish of the seat. On the other hand, the armature 1 of the seat being advanced to the maximum, the space between the hull 50 of the seat and the knees of a rear passenger, even large, is more than enough not to interfere. If the front passenger wishes to improve his sitting comfort by moving back the armature 1 of the seat, it must first lift the spreader 27 so as to allow the sliding of the movable elements before 25A, 26A and rear 25B, 26B of the slides 25 , 26 on fixed rails 25C, 26C mounted on the floor of the vehicle. The armature 1 of the seat can then move freely backwards. During this movement, the pulley 71 mechanically connected to the rear movable member 25B retreats. Its notched flange 71A moves along the rack 72 which causes it to rotate (and the hub 71B) around the axis 71C. The cables 73 and 74 then gradually wind around the hub 71B while sliding at the same time in the guide elements 75, 76, 77, 78, 79. The traction exerted on these cables has the effect of straightening them and then to increase their voltage, so that the four cable gland tabs 84, 85, 86, 87, are biased forward as well as the movable central portion 52 on which the latter are welded. As soon as the force exerted by the cables 73, 74 on this movable central portion 52 is greater than the restoring force of the four springs 63, 64, 65, 66, this moving part 52 is driven in translation forward while the springs are compressed.

When the armature 1 reaches its rear stop position, the shell 50 occupies its comfort configuration shown in FIGS. 1 and 4 and in which the mobile central portion 52 is shifted forwards as far as possible relative to the frame 51 of the In this configuration, it will be noted that the portion of the cable 73 located between the tabs 79 and 81 is rectilinear, so that the four tabs 79, 84, 85 and 81 are aligned. Similarly, the portion of the cable 74 located between the tabs 82 and 83 is rectilinear, so that the four tabs 82, 86, 87 and 83 are aligned.

Thus, the hinge device 70 compensates for a portion of the space lost by the rear passenger when the frame 1 of the front seat is moved back. This rear passenger benefits and even when it is large and that the frame 1 of the front seat is in the rear stop position, a minimum of space between his knees and the movable portion 52 of the hull 50. When the armature 1 of the seat is advanced again, the pulley 71 reverses, the cables 73 and 74 relax and the springs 63, 64, 65, 66 push the movable central portion 52 so that the shell 50 resumes its Initial alignment configuration.

According to alternative embodiments not shown: - the mobile part of the shell is shaped differently; - The translational displacement means are different, and include for example electromagnets activatable by a control device; and / or - the return means are distinct and comprise, for example, two permanent magnets which attract each other. Of course, the present invention is not limited to the embodiments described and shown, but encompasses any variant embodiment.

Claims (14)

REVENDICATIONS1. Seat intended to be slidably mounted on the floor of a motor vehicle and having a backrest (40) whose rear face is constituted by a shell (50); said seat being characterized in that said shell (50) comprises a frame (51) integral with the frame (41) of said backrest (40) and a movable central part (52), said movable central part (52) being able to move in translation vis-à-vis said frame (51) along an axis transverse to said folder (40). 2. Seat according to claim 1, characterized in that it comprises means (70) capable of driving in translation forwardly said movable central portion (52) when said seat slides towards the rear of the floor of said vehicle. 3. Seat according to claim 2, characterized in that said drive means (70) are provided to pass said shell (50) of an alignment configuration in which the rear faces of said frame (51) and said moving central portion (52) are located in the same plane, a comfort configuration in which the rear face of said movable central portion (52) is located in front of the rear face of said frame (51). 4. Seat according to one of claims 2 or 3, characterized in that said drive means (70) comprise a pulley (71) rotatably mounted on an axis (71C) and at least one cable (73; ), passing through at least one cable gland (84, 85; 86, 87) integral with said movable central portion (52), the ends of which are fixed respectively to said frame (51) and to said axis of rotation (71C); said cable (73; 74) wrapping around said pulley (71) while being stretched when said seat slides towards the rear of the floor, so that said movable central portion (52) is driven in translation forwards by said cable gland (84, 85; 86, 87). 5. Seat according to claim 4, characterized in that it is slidably mounted on said floor by means of two slides (25; 26) each comprising at least one movable member (25A, 25B; 26A, 26B) integral with of said seat and adapted to slide axially along a corresponding rail (25C; 26C). 6. Seat according to claim 5, characterized in that said drive means (70) further comprises a rack (72) disposed along a said rail (25C) to which it is attached; said pulley (71) being integral with said movable member (25B) slidable along said rail (25C), and having a notched flange (71A) cooperating with said rack (72) so that said pulley (71) is rotated when said seat slides on the floor. 7. Seat according to one of claims 4 to 6, characterized in that said drive means (70) comprise two said cables (73; 74), each of them having a portion extending horizontally over the width of said shell (50) between a first pair of tabs (80, 81; 82, 83) attached to the legs (42, 43) of said frame (41), each said horizontal portion of a said cable (73; a second pair of tabs (84, 85, 86, 87) integral with said movable central portion (52) of the shell (50). 8. Seat according to claim 7, characterized in that said cables (73; 74) are wrapped around said pulley (71) while stretching when said seat slides towards the rear of the floor, so that said movable central portion (52) is translationally driven forward by said second pair of tabs (84,85; 86,87). 9. Seat according to claim 8, characterized in that the four tabs (80, 84, 85, 81; 82, 86, 87, 83) forming the first and second pairs of tongues of each said cable (73; find aligned when said shell (50) occupies its comfort configuration. 10. Seat according to one of claims 7 to 9, characterized in that each said cable (73; 74) comprises a first generally vertical portion extending from said pulley (71) to a corresponding corner trip (78). 79), at right angle, forcing it to fork horizontally. 11. Seat according to one of claims 3 to 10, characterized in that it comprises elastic return means (63, 64, 65, 66) continuously urging said shell (50) to said alignment configuration. 12. Seat according to claim 11, characterized in that said elastic return means comprise at least one helical compression spring (63, 64, 65, 66). 13. Seat according to claim 12, characterized in that said biasing means comprise four said springs (63, 64, 65, 66), each said spring being disposed between a transverse bar (61, 62) integral with said frame (41) and said central movable portion (52) of the shell (50), near each of its four corners. 14. Seat according to claim 13, characterized in that it comprises two said transverse bars (61; 62) from each of which extend two said springs (63, 64; 65, 66).