FR2929179A1 - Motor vehicle's seat, has advancement control unit to place fixation mechanism in inactive position to displace backrest with respect to chassis from nominal position towards forward position by rotation of foot with respect to chassis - Google Patents

Abstract

The seat has a foot adapted to be mounted on a chassis in a rotating manner with respect to the chassis. A fixation mechanism is mounted on the foot and is adapted to alternatively take an active position in which the foot is fixed to the chassis and an inactive position in which the mechanism liberates the foot from the chassis. An advancement control unit is adapted to place the mechanism in the inactive position to displace a backrest (6) with respect to the chassis from the nominal position towards the forward position by rotation of the foot with respect to the chassis.

Description

The present invention relates to motor vehicle seats, and to vehicles with such seats. More particularly, the invention relates to a motor vehicle seat comprising: a foot adapted to be mounted on a vehicle chassis, a backrest rotatably mounted on the foot about a first axis of rotation, a mechanism for tilt lock mounted between the backrest and the foot, and adapted to alternatively take an active state in which it prohibits an inclination of the backrest relative to the foot about the first axis of rotation, and an inactive state in which it allows the inclination of the backrest relative to the foot about the first axis of rotation, 20 - a seat pivotally mounted on the backrest about a second axis of rotation located above the first axis of rotation in the nominal position of use of the seat, wherein an occupant sits in the seat, a linkage comprising at least one forward linkage including a first end adapted to be pivotally mounted relative to the frame around a third axis of rotation, and a second end mounted on the seat, a tilt control system adapted to place the tilt lock mechanism in its inactive state, to move the backrest relative to the foot from the nominal position to a folded position in which the folder extends parallel to the seat 35 by rotation of the backrest relative to the foot about the first axis of rotation. The document FR 2 851 211 describes an example of such a seat, which provides complete satisfaction. However, efforts are made to increase the volume of space behind the seat, for example in the case where it is desired to access a row of seats located at the rear of the seat in question by a door at the level of of the seat in question. For this purpose, according to the invention, a seat of the kind in question is characterized in that the foot is adapted to be mounted on the frame rotatably relative to the frame, and in that the seat further comprises: a member fastening device mounted on the foot and adapted to alternatively take an active state in which it allows to fix the foot to the frame and an inactive state in which it releases the foot of the frame and allows a rotational movement of the foot relative to the frame, a a forward control system adapted to place the attachment mechanism in its inactive state, to move the backrest relative to the chassis from the nominal position to an advanced position by rotation of the foot relative to the chassis.

With these provisions, it increases the volume at the rear of the seat in its advanced position. Rotary means here as well a pivoting movement - a translational movement along a curved path, if necessary circular, moving away the part of the foot attached to the support of the support. In preferred embodiments of the invention, one or more of the following arrangements may be used in addition: the tilting locking mechanism is maintained in its active state during a displacement the backrest relative to the support from the nominal position to the advanced position; - A movement of the backrest relative to the foot from the nominal position to an intermediate inclined position between the nominal positions and folded down after actuation of the advance control causes the placement of the fixing mechanism in its inactive state; the foot comprises: a base on which the backrest is mounted by means of the tilting locking mechanism, a slideway, comprising a fixed profile adapted to be fixed to the frame, and a movable section adapted to slide relative to to the fixed profile along a sliding direction, the first end of the connecting rod is rotatably mounted on the movable section, the base is mounted on the movable section via the fastener; - The foot comprises a slideway, comprising a fixed section adapted to be mounted on the frame by means of the fastener, a movable section adapted to slide relative to the fixed profile along a sliding direction, and a sliding locking mechanism adapted to alternatively take an active state in which it prohibits a relative displacement of the fixed and movable sections along the direction of sliding, and an inactive state in which it authorizes said sliding, the first end of the connecting rod front is rotatably mounted on the frame, and the backrest is rotatably mounted relative to the movable section about the first axis of rotation; movement of the backrest relative to the foot 35 from the nominal position to the inclined position following actuation of the advance control causes placement of the sliding locking mechanism in its inactive state, and movement of the movable section relative to the fixed profile along the sliding direction to a predetermined longitudinal position causes placement of the fixing mechanism in its inactive state; the seat comprises a securing mechanism comprising a first part carried by the movable section, and a second part carried by the front link, the securing mechanism being adapted to take alternately an active state in which the first and second parts are secured, and an inactive state in which the first and second parts are disengaged from one another, the securing mechanism from its inactive state to its active state in said predetermined longitudinal position - the linkage comprises a rear connecting rod and an intermediate connecting rod disposed between the front link and the rear link, the rear link and the intermediate link each comprising a first end rotatably mounted on the frame and a second end rotatably mounted on the foot; - The foot is pivotally mounted relative to the frame about a fourth axis of rotation; the upper end of the front connecting rod is pivotally mounted on the seat around a fifth axis of rotation; the seat further comprises an additional locking mechanism, adapted to alternatively take an active state in which it prohibits a relative rotation of the seat and the front link, and an inactive state in which it allows this rotation, the system The tilt control system is adapted to place said additional locking mechanism in its inactive state, the advance control system is adapted to place said tilt adjustment mechanism in its inactive state. In another aspect, the invention relates to a motor vehicle comprising a frame and at least one such seat, the foot and the first end of connecting rod before 10 being mounted on the frame. Other features and advantages of the invention will become apparent from the following description of five of its embodiments, given by way of non-limiting example, with reference to the attached drawings. In the drawings: - Figure 1 is a schematic side view of a seat according to a first embodiment, in the nominal position, - Figure 2 is a partially sectional plan view along the line II-II of Figure 3 an example of an inclination locking mechanism; FIG. 3 is a sectional view along line III-III of FIG. 2 of the mechanism of FIG. 2; FIG. 4 is a sectional view of FIG. 5a and 5b are views corresponding to FIG. 1 of the seat of FIG. 1 in respectively inclined and folded positions of the seat, FIGS. 6a and 6b are views corresponding to FIG. 1 of the seat of FIG. 1 in respectively intermediate and forward positions of the seat, FIG. 7 is a partial exploded view in perspective of an example of a guide rail, FIGS. 8a, 8b and 8c are views corresponding to Figures 1, 5a and 6b, respectively, p In a second seat embodiment, Fig. 8d is a view corresponding to Fig. 8a of the seat of Fig. 8a in front adjustment position; Fig. 9a is a view corresponding to Fig. 1 for a third embodiment. in the nominal position, FIG. 9b is a view corresponding to FIG. 9a of the seat of FIG. 9a, in an inclined position; FIG. 9c is a view corresponding to FIG. 9a of the seat of FIG. 9a; in the advanced position, FIGS. 10a and 10b are views corresponding to FIGS. 9a and 9b, respectively, of a fourth seat embodiment, respectively in nominal and inclined position, FIGS. 10c, 10d and 10e are views corresponding to FIG. 10a of the seat of FIG. 10a at various intermediate stages between the nominal position and the advanced position of FIG. 10e; FIGS. 11a, 11b, 11c and 11d are views corresponding to FIG. a ci nth embodiment of seat, respectively in the nominal position, folded down, inclined and advanced. In the different figures, the same references designate identical or similar elements. Figure 1 shows a seat 1 of a motor vehicle adapted to receive one or more occupants, and mounted on a chassis 2 of a motor vehicle. Such a seat can be mounted in various orientations in the vehicle, the front, rear, left, right and other orientation terms relating to the seat in the description referring only to the orientation of the seat itself, regardless of the orientation of the seat in the vehicle. For example, such a seat can be occupied by an occupant ascending into the vehicle via a side door 4 of the vehicle arranged facing one side of the seat. The seat defines, in its nominal position shown in Figure 1, a space 3 located at the rear of the seat, and suitable for receiving objects to store, or at least one seat (the front end of the seat is 5) identical or different from the seat 1, for example arranged in an orientation similar to that of the seat 1, and not having an access door disposed behind the door 4 to access the seat 1. According to a first embodiment shown in Figure 1, in its nominal position in which an occupant classically takes place in the seat, the seat 1 has a backrest 6, for receiving the back of the occupant, rotatably mounted on a foot 7 around a first axis of rotation X1. This rotary assembly can be done by means of a tilt adjustment mechanism 17 of any known type such as for example described below in relation to FIGS. 2 and 3. The foot 7 comprises a base 77 and is fixed on the frame 2 of the vehicle. According to the embodiment shown in Figure 1, the foot 7 comprises a longitudinal adjustment mechanism 18 of any known type, such as a slide shown in Figure 7, for adjusting the longitudinal position of the base 77 relative to the chassis 2 of the vehicle according to a sliding axis Y. Such a slideway may comprise a movable section 20 and a fixed profile 22. In this case, the seat comprises, in a manner known per se, a sliding control member 19 such that, for example, a spreader disposed under the seat, and adapted so that the user can, by actuating, move the seat between rear and front positions. The fixing of the base 77 on the movable section 20 is releasably carried out by any appropriate attachment mechanism 9, such as for example a mechanism as described below in relation to FIG. 4.

The seat also has a seat 10 adapted to receive the pelvis and legs of the occupant. The seat 10 extends from a rear end to a front end. At the rear end, it is mounted on the backrest 6, pivoting relative to the backrest about a second axis of rotation X2. This pivotal connection is for example made as a simple pivot having no locking mechanism. The second axis of rotation X2 is located above the first axis of rotation, in the nominal position of the seat. At the front end, the seat is pivotally mounted on a set of rods before 11 around a fifth axis of rotation X5 (only one front link is visible in Figure 1). The front connecting rods 11 are for example arranged laterally on either side of the seat and extend from an upper end where they carry the fifth axis of rotation X5 at a lower end where they are mounted on the frame 2, and pivoting relative to the frame 2 around a third axis of rotation X3. Furthermore, the base 77 is rotatably mounted relative to the frame, for example by means of a linkage comprising two parallel rear rods 12, and two parallel rods 13 parallel (only one intermediate link and rear visible in Figure 1). The intermediate rods are mounted between the front and rear rods. The intermediate and rear connecting rods each have a first end pivotally mounted on the movable section 20 and a second end pivotally mounted on the base 77, so that the base 77 can describe a translational movement circular relative to the slide fixed to the frame.

The seat 1 of this first embodiment has a folding control member 14 such as, for example, a handle located on one side of the backrest, and adapted so that the user can, by actuating, bring the seat in a folded position in which the backrest extends substantially parallel to the seat. This folding control member 14 is part of a folding control system, for example cable, for transmitting the control of the folding of the occupant to the various useful mechanisms of the seat. The seat 1 of this first embodiment also has a progress control member 15 such as, for example, a handle located on the top of the rear face of the backrest near the door 4, and adapted so that the By actuating it, the user can bring the seat into an advanced position in which the seat extends substantially forward with respect to the nominal position of FIG. 1, so as to increase the space 3. Advancement 15 is part of an advancement control system, for example cable, for transmitting the advance control of the occupant to the various useful mechanisms of the seat. Where appropriate, depending on the characteristics of the tilting lock mechanism, the seat 1 may also have a tilt adjustment control member 16 such as, for example, a handle located directly on the tilt lock mechanism 17 , and adapted so that the user can, by actuating, adjust the inclination of the backrest relative to the foot in a so-called comfort adjustment corner zone in which it can take place in the seat. Where appropriate, if appropriate, the same member serves as tilt adjustment control member and tilt control member, the two functions being differentiated by different positions or operating directions different from the organ. An illustrative example of an inclination locking mechanism is described below in connection with FIGS. 2 and 3.

As shown in FIGS. 2 and 3, the inclination locking mechanism 17 comprises: a first base plate 101 which is fixed on the foot 7, a second mobile plate 102 fixed on the backrest 6, and which pivots about the first axis of rotation X1, the fixed and movable flanges together forming a round housing, and the movable flange 102 having a circular toothing 103 oriented radially inward and disposed inside the housing, - a ring of sheet 104 which is crimped around the periphery of the fixed flange 101 and which partially covers the mobile flange 102 to close the housing and keep the edges of the two flanges against each other, - three metal grains 105 (a single grain being represented in FIG. 2) each provided with an external toothing 106 capable of cooperating with the internal toothing 103 of the mobile flange, these three grains being guided in radial sliding in guide grooves 107 aged in the fixed flange, the sliding directions of the three grains being shifted mutually by 120 degrees about the axis X1, a cam 108, rotatable about the axis XI and acting on the three grains 105, this cam being displaceable angularly between, on the one hand, a rest position where it pushes the grains to a locking position for which the external teeth 106 of the grains cooperate with the internal toothing 103 of the mobile flange thus blocking said movable flange, and other part, an unlocking position for which said cam allows the grains 105 to move back to an erased position for which their external teeth are disengaged from the internal toothing of the movable flange, - three springs 109, here constituted by spirally wound blades, which angularly bias the cam 108 towards its angular position of rest corresponding to the locking of the articulation (springs of which only one has been represented in FIG. 2), and a shaft 110 of axis XI integral with the cam 108 and connected to the folding control handle 14. In addition, there is provided on each grain 105 a pin 112 projecting therefrom. grain in the direction of the axis XI, and is made integral with the movable flange 102 a track 111 with projections surrounding the pins 12 (shown in phantom in Figure 2), comprising arcs of circle A and B of different diameters centered on the axis X1, the diameters of the arches A and B being determined so that: - when a larger diameter portion A is opposite a pin 112, the latter, and therefore the corresponding grain 105, can describe the whole of its radial stroke (see Figure 2), and that, on the contrary, when a small diameter segment B is opposite said pin 112, after an angular displacement relative sufficient of the track 111 and the pin 112 around the axis XI (due to the rotation of the file) said pin 112 is radially in abutment on said section B in its disengaged position, the closest to the axis X, corresponding to the unlocking of the articulation. This measurement makes it possible to keep the grains 105 in their unlocked unlocking positions, even if the user releases the handle 24 as long as the backrest is in an inclined position such as a portion of an arc B of the track 111 is located radially opposite each of the pins 112. The angular positions in question of the backrest are defined in an angular zone for which it is desired that the joint remains unlocked, and correspond, for example, to the folding of the backrest to the front. at the tablet position. The section A defines the angular zone of tilt adjustment. In addition, there is provided on each grain 105 a second pin 113 protruding on the grain in the direction of the axis X1, and is made integral with the cam 108 a thin plate 114 recessed by lights 115 each traversed by one second lumen 113. Each lumen 115 is elongated circumferentially around the axis X and its edge farthest from this axis has a projection in that it comprises two circular arcs D and E of different diameters connected to each other by an oblique ramp R. The diameters of the arches D and E are determined in such a way that: - when the arc D of larger diameter is radially opposite the corresponding pin 113, it is free to describe the totality its radial stroke, 25 and that, on the contrary, when the arc E of smaller diameter is opposite the pin, this arc is then applied radially against this pin and holds it in its position closest to the axis corresponding to the unlocked age of the joint. Due to the obliquity of the ramp R, a simple rotation of the plate 114 allows, by sliding the pin 113 against this ramp, to positively move the latter to its unlocked position. The inclination locking mechanism 17 can be connected on the one hand by its second flange 102 to a lateral arm of the backrest frame, and by means of its first flange 101 to the foot 7. Another mechanism of tilt lock may also be disposed between another side arm of the backrest frame and another foot 7, the connection between these two mechanisms being provided by any suitable means to ensure that they are both simultaneously in a locked state or unlocked. Figure 4 now shows an example of attachment mechanism 9. This attachment mechanism is shown here for illustrative purposes only, and any other type of suitable attachment mechanism could also be used in the context of the present invention. It is therefore limited to recall that such a fixing mechanism may, according to the example shown, before fixing the base 77 to the movable section 20 of the slideway, be in the form of a substantially cylindrical body 32 fixed vertically under the base 77, for example by means of a fixing plate 33. Before fixing the base 77 on the slideway, an internal spring 34 pushes a control rod 35 in contact with a plurality of balls 36 maintained in an inactive position inside the cylindrical casing of the body 32 by a cylindrical ring 37. During insertion of the body 32 into a cylindrical opening 31 of the movable section, of a size corresponding to the diameter of the body 32, the ring 37 is withdrawn and the balls 36 are biased outwardly of the body 32 by the downward displacement of the control rod 35 biased by the internal spring 34. The balls 36 are however retained by the body 32 because it s have a diameter too large to be able to fully exit the recesses formed for their effect, and engage under the lower surface 42a of the horizontal base 42 of the movable section 20, to prevent vertical movement upwardly of the base 77 in this active position. The advanced control handle 15 is connected to the control rod 35 to move it up against the bias of the spring 34, to unlock the fastening system. The balls 36 are then free to retract inside the body, and the body 32 to be removed from the movable section 20 by a vertical movement upwards. The slide 18 generally comprises a movable section 20 on which is fixed a connecting section 21 (Figure 1). This connecting section pivotally supports the lower ends of the front 11, intermediate 13 and rear 12 connecting rods. The movable section 20 is slidably mounted with respect to a fixed profile 22 in a longitudinal direction Y so that the occupant of the seat can adjust its longitudinal position by a relative displacement of the movable section 20 and the fixed profile 22. FIG. 7 describes an embodiment of a slideway 18 equipping the seat of FIG. 1, and of its sliding locking mechanism, however this example is given for illustrative purposes, and any other type of slide adapted than that presented here in connection with Figure 7 may be used within the scope of the invention. Therefore, it will be recalled that in this example, the fixed section 22 is a female section between the wings 23 which is inserted a male section: the movable section 20. The movable section 20 is a U-shaped section with a base horizontal 42 which extends parallel vertical flanges 43. The locking mechanism comprises a number of recesses 24 formed in the flanges 23 of the fixed profile, recesses 25, formed in the flanges 43 of the movable section facing the recesses 24 of the fixed profile, and a blade 26 mounted inside the movable section 20 and having teeth 27 which cooperate with both the recesses 25 of the movable section and 24 of the fixed profile in the locked position of the locking system slide.

The seat just described works as follows. The nominal position of use has already been described above with reference to FIG. 1. For comfort adjustment of reclining of the backrest in the comfort adjustment range, the occupant actuates the handle 16 so as to unlock the mechanism of Inclination lock 17. The backrest 6 is then free to rotate relative to the foot 7. Due to the connection between seat and backrest, this rotation is accompanied by a slight substantially horizontal displacement of the seat 10. When it has reached the desired position, the occupant releases the handle 16 and, subject to always being in the comfort setting range (arc A) of the tilt lock mechanism 17, the latter resumes its locked position. When the user wishes to place his seat in said tablet position, he actuates the folding handle 14, which causes the unlocking of the tilt lock mechanism 17. The user is then free to rotate the folder 6 forward with respect to the foot 7 as shown in Figure 5a. Due to the position of the pivot axis X2 above the pivot axis XI in the nominal position of the seat, this rotation of the backrest results in a significant displacement of the seat 10 forward. In the tablet position shown in Figure 5b, where the backrest 6 extends substantially horizontally and / or parallel to the seat 10 and / or parallel to the floor of the vehicle, the seat 10 has substantially advanced to the before, for example to reduce the interference between the side cushions backrest and seat in this position. The seat thus holds in a reduced height in this position. When the user wishes to place the seat in an advanced position, in which the seat can no longer be occupied, and in which the volume of space 3 at the rear of the seat is increased, it actuates the advanced handle 15, which has the effect of placing the fastening mechanism 9 in its inactive state. The base 77 is then released from the frame 2. As shown in FIG. 6a, the base 77 is then moved substantially upwards and forwards relative to the frame, for example by a circular translational movement via intermediate rods 13 and rear 12. The slides remain attached to the frame. The tilting lock mechanism 17 remains locked during this movement. As shown in Figure 6b, the seat can be placed in an advanced position in which it extends substantially vertically in a space of reduced length, due to the rotation of the seat 10 relative to the backrest 6 around the X2 axis. When an occupant uses the sliding control system 19, he imparts a vertical downward movement to the unlocking control rod 28 and consequently to the blade 26 inside the movable section 20 against means of disengagement. urging tending to bring the blade 26 in its locked position. The teeth 27 of the blade 26 are displaced downwardly to leave at least the recesses 24 of the fixed profile 22. The slide locking system is then in an unlocked position in which the sliding of the movable section relative to the fixed profile along the longitudinal direction is allowed. It will be noted that, in a variant of the embodiment of FIG. 1, a seat may not include such slides, the profile 21 being directly attached to the frame 2. A second seat embodiment is shown in the nominal position. , in Figure 8a.

In this embodiment, the elements common to the first embodiment are not described again. In this embodiment, the base 77 is fixed irremovably on the movable section 20 of the slideway. The fixed profile 22 of the slide has a rear end which is releasably fixed to the frame 2 by means of a fastening mechanism 9, for example of the same type as that of the first embodiment. The front end of the fixed profile 22 is rotatably mounted on the frame 2, for example by pivoting about a pivot axis X4. The lower end of the front connecting rods 11 is pivotally mounted directly on the frame 2. The advance control member 15 is adapted both to control the unlocking of the articulation 17 and the fixing mechanism 9. To place the seat in the advanced position, the user actuates the advance handle 15. This has the effect of unlocking the hinge 17. In addition, the slide 18 has been released from the floor, at its rear end, and has turned around. of the X4 axis, as shown in Figure 8c. On the other hand, if the user wishes to place the seat in the tablet position, he actuates the corresponding control handle 14, which has the effect, as previously, of unlocking the tilt lock mechanism 17 without unlocking the mechanism of release 9, whereby the backrest can be inclined (Figure 8b) and folded into a tablet position substantially similar to that of Figure 5b. If the occupant wishes to adjust the longitudinal position of the seat, he actuates the spreader 19, which has the effect of separating the movable section 20 of the fixed profile 22, as explained above, so as to allow the sliding of the base 77 , and the backrest 6, for example forward, as shown in Figure 8d. It should be noted that this forward movement is then accompanied by a slight displacement forward and downward of the seat 10. FIG. 9a shows a third embodiment of seat in the seat. nominal position. The arrangements common to the first embodiment and this embodiment will not be described again here. This third embodiment differs from the first embodiment in that the base 77 is no longer mounted on the frame 2 by means of the intermediate 13 and rear 12 connecting rods but by a simple pivotal mounting about an axis X4 in the front end of the base 77. Furthermore, according to this embodiment, the seat comprises an additional locking mechanism 29 of any suitable type, disposed between the seat 10 and the front rods 11. Such a locking mechanism 29 alternatively can take an active state in which it prohibits a relative rotation of the seat 10 and the front link 11 around the pivot axis X5, and an inactive state in which it allows this rotation. In this embodiment, the crimping control member 14 is adapted to unlock both the tilt lock mechanism 17 and the lock mechanism 29. The advance control member 15 is adapted to unlock at a time. Both the tilt lock mechanism 17 and the attachment mechanism 9. In this embodiment, the tilt adjustment of the backrest 6 for the postural comfort of the occupant is identical to the first embodiment. through the tilt adjustment control member 16. If the user wishes to place his seat in said tablet position, he actuates the tilt control member 14, so as to cause the the unlocking of the tilting lock mechanism 17 and the locking mechanism 29 between the front link 11 and the seat 10. The user is then free to rotate the backrest forward, as shown in FIG. 9b, until reaching a folded position substantially identical to that shown in Figure 5b. Of course, the user can then return the seat to the nominal position of Figure 9a, in which position the tilt locking mechanism 17 and the locking mechanism 29 resume their active state. If the user wishes to place the seat in an advanced position, it actuates the advance control member 15, which has the effect of placing in their inactive state both the tilt lock mechanism 17 and the mechanism 9. Therefore, on the one hand the backrest 6 is free to rotate relative to the base 77 about the axis XI and, on the other hand, the foot 7 is free to rotate relative to the frame 2 around of the X4 axis. However, the locking mechanism 29 remains locked. The user is therefore free to bring the seat in the advanced position shown in Figure 9c. Note that during the displacement of the seat from the nominal position of Figure 9a to the advanced position of Figure 9c, the backrest 6 has rotated substantially clockwise in these figures relative to the foot 7 , which had the effect of increasing the angle formed between the backrest 6 and the seat 10. Therefore, the seat extends substantially vertically in the advanced position, which allows to free up a maximum of space 3 at the back of the seat. The seat can be brought from its forward position of Figure 9c to its nominal position of Figure 9a by a counter-movement, the tilting lock mechanism 17 and the attachment mechanism 9 resuming their active state in the nominal position. It will be noted that the lower ends of the front connecting rods 11 and the base 77 may be directly rotatably mounted on the chassis of the vehicle, respectively in the axes X3 and X4, and the base 77 releasably fixed on the chassis 2 by the fixing mechanism 9. As a variant not shown, the seat may include slides for adjusting the longitudinal position of the backrest in the vehicle. In this case, the fastening mechanism 9 is formed between the base 77 and the sliding rail section, and the lower end of the front link and the front end of the base 77 are pivotally mounted on this section. A fourth embodiment is shown in Figure 10a, in nominal position. The components of this embodiment which are identical to the first embodiment will not be described again here. In this fourth embodiment, the foot 7 comprises a base 77, and a slide 18. The base 77 is fixed permanently on the movable section 20 of the slide. The fixed section 22 of the slide has a rotatably mounted front end, for example pivoting about an axis X6 on the floor. The fixed profile 22 of the slideway also has a rear end which is releasably mounted on the floor via a fastening mechanism 9 for example of the type described above with reference to the first embodiment. Furthermore, this fourth embodiment comprises a two-part fastening mechanism 30 comprising on the one hand a first part 38 secured to the movable section 20, and formed for example by a notch at the front end of the base 77, and a second part 39 formed on a front rod 11, and of complementary shape to the first part 38, such as for example a pin 39.

The securing mechanism may take alternately an inactive state, shown in FIG. 11a, in which the first and second parts 38, 39 are separated from each other, and an active state, shown below, in which the first and second portions 38, 39 are connected to each other. Furthermore, the advance control member 15 is adapted to control the unlocking of the inclination locking mechanism 17, and for a rotation of the backrest 6 relative to the base 77 about the axis XI to- beyond a predetermined angular position controls the placement of the slide lock mechanism in its inactive state, and that the movement of the movable section 20 relative to the fixed section 22 beyond a predetermined longitudinal position controls the placement of the mechanism. 9 in its inactive state. As in the first embodiment, the tilt adjustment control member 16 controls unlocking of the tilt lock mechanism 17 for tilt adjustment in a comfort range, without influencing other mechanisms from the headquarters. As in the first embodiment, the crimping control member 14 is adapted to control the placement of the tilt lock mechanism 17 in its inactive state, without the rotation of the backrest 6 relative to the base 77 in the predetermined angular position controls the placement of the slide lock mechanism in its inactive state. As in the first embodiment, the sliding control member 19 is adapted to place the slide locking system in its inactive state, without any displacement of the movable section 20 with respect to the fixed section 22 in the longitudinal position. predetermined causes the placement of the fastening mechanism 9 in its inactive state.

The seat just described works as follows. The tilt adjustment of the backrest 6 in the comfort range is via the tilt adjustment controller 16 as previously described in connection with the first embodiment. If the user wishes to bring the seat 1 in the so-called tabling position, it actuates the folding control member 14 as has been previously described in connection with the first embodiment, so as to tilt the file 6 towards the front, as shown in Figure 10b, until reaching a so-called tablet setting position substantially identical to that shown in Figure 5b for the first embodiment. During this movement, the securing mechanism 30 remains in its inactive state. Then, the user can simply return the seat to its nominal position of Figure 10a, by an opposite movement.

If the user now wishes to bring the file to an advanced position, it actuates the advance control member 15, which has the effect of placing in its inactive state the tilt locking mechanism 17, thus allowing the rotation backrest 6 relative to the base 77 to a predetermined angular position, shown in Figure 10c. This rotation of the backrest 6 is accompanied by a forward rotation of the front links 11. In the predetermined angular position of Figure 10c, the slide locking mechanism 18 is placed in its inactive state. This can be done, in a manner known per se, for example, by a boss formed on the backrest 6 opposite the release control rod 28 (FIG. 7) of the slide, situated at a distance from this rod 28 in the nominal position. and moving this rod down into the predetermined angular position, so as to put the slide lock mechanism in its inactive state. The base 77 is then free to slide relative to the fixed profile 20 along the sliding axis Y, and in particular to the predetermined longitudinal position shown in FIG. 10d. During this translation, the front link 11 has again been rotated forwards about the axis X3 so that the notch 38 is secured to the pin 39 in this predetermined longitudinal position, thus placing the mechanism of solidarity in its active state. In this predetermined longitudinal position of FIG. 10d, the attachment mechanism 9 is automatically placed in its inactive state, so that the continuation of the movement is done by rotating the fixed profile 20 with respect to the floor 2 about the axis X4 as shown in Figure 10e. During this step, the securing mechanism remains in its active state. In addition, the displacement between the positions of Figures 10d and 10e is accompanied by a substantially backward rotation of the backrest 6 relative to the base 77 about the axis of rotation XI which leads to an increase in the angle between the backrest 6 and the seat 10 which allows, in the advanced position, not shown, to release a maximum of space 3 at the rear of the seat. The user can return the seat to the nominal position of Figure 10a by an opposite sequence of movements. Finally, if the user wishes to adjust the longitudinal position of the seat, he can do it, in a conventional manner, by means of the sliding control member 19. A fifth embodiment is shown in FIG. nominal position. The elements common to the first embodiment and to the fifth embodiment will not be included in the description thereof hereinafter. In this fifth embodiment, the base 77 is pivotally mounted on the movable section 20 of the slideway 18 around a pivot axis X4. Furthermore, the base 77 is shaped so that a rotation thereof relative to the movable section about the axis X4 beyond a predetermined inclination position automatically controls the unlocking of the locking system. This can for example be achieved by forming the front end of the base 77 with a rod 41, which, rotating about the axis X6, will move down the unlocking control rod 28 (FIG. 7) of the slide and thus unlock the slide lock system. The embodiment which has just been described operates as follows. If the user wishes to place the seat in said shelf position, it actuates the crimping member 14, which has the effect of placing the tilt lock mechanism 17 in an inactive state, the folder 6 being then free to rotate relative to the base 77 about the axis XI to a said tablet position shown in Figure 11b.

The user can return the seat to the nominal position of Figure 13a by a reverse movement. If the user wishes to place the seat in an advanced position, it actuates the advance control member 15, which causes the placement of the fixing mechanism 9 in its inactive state, whereby the base 77 is free to rotate relative to the slide around the axis of rotation X4. The user can perform this rotation, the tilt lock mechanism 16 remaining in its active state, until reaching the predetermined angular position shown in Fig. 11c, wherein the slide lock system is automatically placed in its state. inactive, which has the effect of disengaging the movable section 22 of the fixed section 20. The user is then free to slide the movable section 22 forward to the advanced position shown in Figure 11d, thus releasing the space 3 located at the back of the seat. The user can return the seat to the nominal position of Figure 11a by a sequence of 15 reverse movements. Furthermore, the user can implement a tilt comfort adjustment, as previously described in connection with the first embodiment, through the tilt adjustment control member 16. Moreover, the user can implement a longitudinal adjustment of the seat position along the Y axis, as described in connection with the first embodiment, with the aid of the slide control member 19. In the According to various embodiments presented above, it is possible to use springs which assist the relative displacement of the various elements once the locking mechanisms associated with these displacements have been placed in their inactive state.

Claims (12)

REVENDICATIONS1. Motor vehicle seat comprising: - a foot (7) adapted to be mounted on a vehicle chassis, a backrest (6) rotatably mounted on the foot about a first axis of rotation (XI), a locking mechanism tilt (17) mounted between the backrest (6) and the foot (7), and adapted to alternatively take an active state in which it prohibits an inclination of the backrest relative to the foot about the first axis of rotation (X1), and an inactive state in which it authorizes the inclination of the backrest relative to the foot around the first axis of rotation, 15 - a seat (10) pivotally mounted on the backrest (6) around a second axis of rotation (X2) located above the first axis of rotation (X1) in the nominal position of use of the seat, in which an occupant takes place in the seat, a linkage (11, 12, 13) comprising at least one front link (11 ) having a first end adapted to be pivotally mounted with respect to u a frame about a third axis of rotation (X3), and a second end mounted on the seat (10), a tilt control system (14) adapted to place the tilt lock mechanism (17). in its inactive state, to move the backrest (6) relative to the foot (7) from the nominal position to a folded position in which the backrest extends parallel to the seat by rotation of the backrest relative to the foot around the first axis of rotation (X1), characterized in that the foot (7) is adapted to be mounted on the frame rotatably with respect to the frame, and in that the seat further comprises: a fastener (9 ) mounted on the foot (7) and adapted to alternatively take an active state in which it allows to fix the foot to the frame and an inactive state in which it frees the foot of the frame and allows a rotational movement of the foot relative to the frame , a control system of ava ncement (15) adapted to place the fastening mechanism (9) in its inactive state, to move the backrest (6) relative to the frame from the nominal position to an advanced position by rotation of the foot (7) relative to the frame. The vehicle seat according to claim 1, wherein the tilt lock mechanism (17) is maintained in its active state during a movement of the backrest relative to the support from the nominal position to the advanced position. Vehicle seat according to claim 1, wherein a movement of the backrest (6) relative to the foot (7) from the nominal position to an intermediate angular position between the nominal and folded positions following the actuation of the control advanced (15) causes the fixing mechanism (9) to be placed in its inactive state. A vehicle seat according to any one of the preceding claims, wherein the foot (7) comprises: - a base (77) on which the backrest (6) is mounted by means of the tilt lock mechanism 30 (17), a slide (18), comprising a fixed profile (22) adapted to be fixed to the frame, and a movable profile (20) adapted to slide relative to the fixed profile (22) along a sliding direction (Y), in which the first end of the bielleavant (11) is rotatably mounted on the movable section, wherein the base (77) is mounted on the movable section (20) via the fastener . (9) 5. Vehicle seat according to one of claims 1 to 3, wherein the foot (7) comprises a slide (18) comprising a fixed profile (20) adapted to be mounted on the frame via the fastening member (9), a movable profile (20) adapted to slide relative to the fixed profile (22) along a sliding direction (Y), and a sliding locking mechanism (24,25,27) adapted to alternatively take an active state in which it prohibits a relative displacement of the fixed and movable sections along the sliding direction, and an inactive state in which it authorizes said sliding, wherein the first end of the front link (11) is rotatably mounted on the frame, and wherein the backrest (6) is rotatably mounted relative to the movable section (20) about the first axis of rotation (X1). The vehicle seat according to claims 1, 3 and 5, wherein a movement of the backrest (6) relative to the foot (7) from the nominal position to the inclined position following actuation of the forward control ( 15) causes the sliding lock mechanism (24,25,27) to be placed in its inactive state, and in which movement of the movable section (20) with respect to the stationary section (22) along the sliding direction (Y) to a predetermined longitudinal position causes placement of the fastening mechanism (9) in its inactive state. Vehicle seat according to claim 6, comprising a securing mechanism (30) comprising a first integral part (38) of the movable section (20) and a second part (39) carried by the front link (11), the securing mechanism being adapted to take alternately an active state in which the first and second parts are secured, and an inactive state in which the first and second parts are separated from one another, the securing mechanism passing from its inactive state in its active state in said predetermined longitudinal position. 8. Vehicle seat according to any one of the preceding claims, wherein the linkage comprises a rear connecting rod (12) and an intermediate rod (13) disposed between the connecting rod and the rear connecting rod, the rear connecting rod and the intermediate rod. each comprising a first end rotatably mounted on the frame and a second end rotatably mounted on the foot (7). 9. A vehicle seat according to one of claims 1 to 7, wherein the foot (7) is pivotally mounted relative to the frame about a fourth axis of rotation (X4). Vehicle seat according to one of the preceding claims, wherein the upper end of the front connecting rod (11) is pivotally mounted on the seat (10) about a fifth axis of rotation (X5). 11.A motor vehicle seat according to claim 10 further comprising an additional locking mechanism (29), adapted to take alternately an active state in which it prohibits a relative rotation of the seat and the connecting rod before, and a state inactive in which it authorizes this rotation, wherein the tilt control system (14) is adapted to place said additional locking mechanism (29) in its inactive state, wherein the advance control system (15) is adapted to place said tilt lock mechanism (17) in its inactive state. 12.A motor vehicle comprising a frame and at least one seat according to any one of the preceding claims, the foot (7) and the first end of the front link being mounted on the frame (2).