Abstract:
A motor vehicle seat including a seat part and a foldable seatback including a rear face configured to be situated in a substantially horizontal position when the seatback has been folded. The rear face of the seatback includes an attachment mechanism configured to engage with an independent tray, to hold the tray in an erect position on the rear face once the seatback has been folded.

Description:
BACKGROUND 
     The invention relates to a vehicle seat which is provided with means for fixing a removable tray. Vehicle seats are unavoidable and imposing elements in a vehicle passenger space and it may therefore be found to be advantageous to configure them so that they can ensure additional functions, whilst retaining a substantially constant spatial requirement. A vehicle seat according to the invention has been modified in relation to a conventional seat in order to fulfill a new function. 
     BRIEF SUMMARY 
     Vehicle seats provided with a tray exist and patents already relate to them. For example, it is possible to cite the patent FR2911548 which relates to a vehicle seat, the rear face of the backrest of which is provided with a movable tray. More specifically, once the backrest has been folded onto the seat member, the tray is in a substantially horizontal position and can pivot about a vertical axis in order to be able to be moved away laterally at one side or the other of the seat. Although this tray is functional and ergonomic in terms of its support function, it is connected permanently to the seat without being able to be dissociated therefrom, and without being able to be used at a different location from the one in which it is stored on the backrest of said seat. 
     A vehicle seat according to the invention has a foldable backrest which is provided with fixing means which are intended to stow a tray in a deployed position. This is because, once folded, the backrest of the seat is in a substantially horizontal position and may be used as a support platform for a tray, in an operational position for a person sitting in an adjacent seat. The fixing means which are specific to the backrest of the seat cooperate with the tray so that the tray remains in a non-removable manner in a given raised position. A tray in an operational position and a tray which may either be readily read if a text or drawings were visible thereon, or which may be used as a support for a paper document on which it would be possible to write. 
     The invention relates to a seat of a motor vehicle comprising a seat member and a foldable backrest comprising a rear face which is capable of being in a substantially horizontal position once said backrest has been folded down. The main technical feature of a seat according to the invention is that the rear face of the backrest is provided with fixing means which are capable of cooperating with an independent tray in order to retain it in a deployed position on said rear face once the backrest has been folded down. In this manner, the backrest of the seat performs an additional function of support for a tray, once the backrest has been folded down. The expression “substantially horizontal” is intended to mean “horizontal” to within plus or minus 5°. An independent tray is a tray which is not permanently connected to the rear face of the backrest of the seat. That tray is configured as an object which is dissociated from the seat in terms of the fixing means in order to be stowed in a non-removable manner on the rear face of the backrest. The tray may represent a large number of objects such as, for example, a games console, a portable computer or a paper document support. A deployed position is a position for which an individual sitting in an adjacent seat in the vehicle could readily read a text or look at drawings or photographs on said tray, under good conditions of comfort and ergonomics, without having to incline his head in an exaggerated manner. The tray is fixed in a sufficiently stable and solid manner to said rear face for an individual to be able to write on sheets of paper secured to said tray or to be able to apply a pressure to a touch screen of a data-processing tablet in order to start a particular function. The fixing means may cooperate with complementary fixing means for the tray, or cooperate directly with said tray. 
     The deployed position is advantageously a position which may be either vertical or inclined but which is not horizontal. In other words, the position of the tray is substantially similar to the inclined position of a written work which an individual would hold in his hand, and which he would read whilst sitting in a comfortable position. 
     In a preferred manner, the fixing means comprise at least one groove which allows the tray to be received and retained in a deployed position on the rear face of the backrest. It is supposed that the width of the groove is compatible with the thickness of the tray so that the tray can be partially accommodated therein. The grooves may equally well be formed in the region of the center of the backrest or in the region of the extreme portion thereof which may be used as a headrest. A specific position of the tray corresponds to each groove, the objective being to orientate the tray towards an adjacent seat. Each groove may be rectilinear or curvilinear. This type of fixing means has particularly small dimensions because the support platform is constituted by the backrest of the seat already present in the vehicle and each groove advantageously replaces a bulky interface component which may be used for fixing the tray in the deployed position thereof. Similarly, for this configuration, it is not necessary for the tray to be provided with complementary fixing means which are capable of cooperating with the fixing means of the seat backrest. This fixing means is simple, has small dimensions and is completely effective. 
     The rear face of the backrest preferably comprises four grooves, two grooves being aligned in accordance with a first axis and the other two grooves being aligned in accordance with a second axis, two grooves of the same axis being used to fix the tray in a given position. With this configuration having four grooves, the tray may thus occupy two separate positions on the folded seat. 
     In an advantageous manner, the two axes intersect each other, the two grooves of the same axis being positioned at one side and the other of the notional intersection location between said axes. In this manner, a first position of the tray is derived from the second position by means of a notional rotation about the intersection location between the two axes. Thus, the tray may be orientated in accordance with two separate positions on the folded backrest by means of a simple pivoting action about itself, said tray having to be withdrawn beforehand from the grooves which it occupies in order to be subjected to said pivoting action. 
     Advantageously, each groove is covered by a biasing element, the tray being engaged in each groove by repelling said element. Each element tends to naturally cover a groove and the tray is must be manipulated in order to move away each of said elements when it is introduced into each of said grooves. Once it is located in its definitive position, each element contributes to locking that position by applying a pressure against said tray. That biasing element, by applying a pressure to the tray, makes it possible to prevent it from having to be introduced too deeply into each groove in order to obtain the stability required. It should be noted that each biasing element is naturally spaced apart from each groove when the tray is introduced into said grooves, thereby requiring no particular effort. 
     According to an embodiment preferred according to the invention, the fixing means are formed so as to stow a tray which is used as a support for a paper document and which has a retention clip for said document. That tray may thus be used for fixing one or more sheets of paper by means of the clip. The fixing means are sufficiently solid not only to allow the tray to be retained in a deployed position but also to allow said tray to withstand the pressure applied by a pen or a pencil held by an individual who is writing on a paper document fixed to said tray. 
     In a preferred manner, the tray is stored in the backrest of said seat when it is in the storage mode. In this manner, the seat allows a double function to be performed, in full and alone, which function is, on the one hand, to store the tray in a stored position and, on the other hand, to allow said tray to be fixed in a functional position. 
     The invention further relates to a tray which is intended to be fitted to a seat according to the invention and whose main technical feature is that it comprises an elongate planar body having at one of the ends thereof an inclined edge which is provided with two lateral lobes and, at the opposite end thereof, a clip which is intended to retain a paper document. A paper document may be, for example, constituted by a single sheet, a block or a book. 
     Finally, the invention relates to a vehicle which comprises a row of at least two seats and the main technical feature of which is that it comprises at least one seat according to the invention. 
     According to a preferred embodiment of a vehicle according to the invention, said vehicle comprises a row of three seats, the central seat of which is in accordance with the invention. In this manner, once the backrest of the central seat has been folded down, the tray may be withdrawn by one of the two occupants of the two adjacent seats and be deployed on the folded backrest with an orientation towards one of said adjacent seats. The driver or the passenger may thus make use of this tray. 
     The seats according to the invention have the advantage of having a constant spatial requirement in relation to a conventional seat already in existence whilst providing a complete function connected with the tray. This is because they simultaneously allow the tray to be fixed in an operational position, for which an individual may read a text on said tray in a comfortable and pleasant manner, and a storage space to be provided for said tray in the storage mode. They further have the advantage of involving a minimum of components for retaining the stored tray in the backrest and for deploying it in a functional position on the backrest, therefore making them easy to produce, involving small dimensions and moderate costs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A detailed description of a preferred embodiment of a seat according to the invention will be given below with reference to  FIGS. 1 to 4 , in which: 
         FIG. 1  is a rear perspective view of a seat according to the invention in a functional position, 
         FIG. 2  is a perspective view of the seat of  FIG. 2  in a folded position, the tray being stored in the backrest, 
         FIG. 3  is the view of  FIG. 2 , the tray being deployed on the folded seat, 
         FIG. 4  is a partial perspective view of the interior of vehicle according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to  FIGS. 1 and 2 , a seat  1  according to the invention conventionally comprises a seat member  2  and a backrest  3  which is capable of pivoting between a functional position for which it is deployed on the seat member  2 , as  FIG. 1  shows, and a substantially horizontal, folded position for which it moves into contact with the seat member, as  FIG. 2  shows. The backrest  3  thus has a first end  4  near the seat member  2  and is mounted so as to pivot about a horizontal and transverse axis  5 , and a second end  6  corresponding to a headrest  7 . It is assumed that a longitudinal axis of the backrest  3  connects the first end and the second end  4 ,  6 . The backrest  3  comprises a rear face in which a tray  9  which is provided with a clip  27  is stored, said tray  9  being planar and having a small thickness, and being arranged on said rear face providing a given continuity in terms of the outer envelope of the seat  1 . 
     With reference to  FIG. 3 , the backrest  3  comprises a location in which there is fixed in a non-removable manner an approximately rectangular receiving frame  11  whose thickness is less than that of the backrest  3 , whose width is identical to that of the backrest  3  and whose length is less than that of the backrest  3 . In this manner, the frame  11  is included in the backrest  3  and partially delimits its width. That frame  11  comprises a recess  12  which has a planar base  13  and which is extended by an indentation  14 . The portion of the recess  12  corresponding to the planar base  13  is delimited by two large parallel segments  15 , by a small segment  16  which is perpendicular to said large segments  15  and by a profiled segment  17  which allows the recess  12  to have a central extension  18 . The indentation  14  is in the form of a base inclined in a direction which accentuates the depth of said recess  12 , said inclined base being in continuation of the planar base  13  in the region of the small segment  15  thereof. The frame  11  has a central overhang  19  of a material which overhangs the indentation  14 , said overhang  19  being positioned in alignment with said indentation  14  without occupying the portion of the recess  14  with a planar base  13 . The recess  12  extends along a longitudinal axis of the backrest  3  so that its central extension  18  is located near the headrest  7  and so that the indentation  14  is located near the rotation axis  5  of the backrest  3  on the seat member  2 . The frame  11  may be withdrawn from the backrest  3  by means of a pressure on a pin  22  which extends from an edge  23  of said frame  11 . A locking mechanism which involves a mechanical stop is positioned in the receiving frame  11  in the region of the central extension  18  of the recess  12 , said mechanism comprising an activation push-button  20  which extends out of the recess  12  between an end edge  23  of said frame  11  delimiting the central extension  18  of the recess  12  and the tray  9 . 
     With reference to  FIGS. 2 and 3 , the tray  9  is constituted by a thin, planar plate  40  of substantially rectangular form, said plate  40  being extended along a longitudinal axis by, on the one hand, an inclined rim  25  having two lateral lobes  26  and, on the other hand, a conventional clamping clip  27  which is configured to retain at least one sheet of paper against the plate  40 . That tray  9  therefore acts as a support for a paper document so that a person may read said document or may write thereon. 
     With reference to  FIG. 2 , in a storage position, the tray  9  occupies the recess  12  so that its inclined rim  25  is in the indentation  14 , the two lobes  26  being positioned at one side and the other of the central overhang  19  of the frame  11  and so that the plate  40  is in contact with the planar base  13  of the recess  12 , the end of the plate  40  comprising the clip  27  cooperating with the locking mechanism. The tray  9  is stored in the backrest  3  without any of its portions extending out of the recess  12 , said tray  9  ensuring a given continuity of the surface, in the region of the rear face of said backrest  3 . When the tray  9  is stored in the receiving frame  11  of the rear face of the backrest  3 , the activation push-button  20  remains accessible from the outer side of the seat  1 . A return element is associated with that push-button  20  so that it remains, by default, in a projecting position in the locking configuration. In this manner, without any pressure on said push-button  20 , the tray  9  is by default locked against the backrest  3  of the seat  1 . The rear face of the backrest  3  corresponding to the headrest  7  comprises four grooves  28  which are arranged in the form of a cross, two grooves  28  being aligned in accordance with a first axis and the other two grooves  28  being aligned in accordance with a second axis, said axes intersecting with each other, each groove  28  of the same axis being located at each side of the notional intersection location of said axes. Each groove  28  is constituted by a rectilinear aperture which has finite length and which is closed by a biasing removable element, each of said elements being connected to a secondary push-button  29  which is positioned near the activation push-button  20 . Each closure element naturally covers the groove  28 , pressure on the secondary push-button  29  bringing about the instantaneous retraction of said element in order to release the groove  28  in order to introduce the tray  9  therein. 
     With reference to  FIG. 3 , once the tray  9  has been withdrawn from the backrest  3 , it may be deployed on said folded backrest  3  in the region of the grooves  28 . This is because two aligned grooves  28  are intended to receive the two lobes  26  of the tray  9  so that it occupies a first position, the other two aligned grooves  28  allowing said tray  9  to occupy a second position. The tray  9  may thus be deployed on the folded seat  1  so as to be in a slightly inclined plane with respect to a vertical plane, the clip  27  constituting its highest zone. 
     With reference to  FIG. 4 , a motor vehicle  50  according to the invention comprises a row of three aligned seats  30 ,  31 ,  32 , the central seat  31  of which is in accordance with the seat  1  previously described. The tray  9  may thus occupy a first position  33  (shown in solid lines in  FIG. 4 ) which is orientated towards a first adjacent seat  30 , or a second position  34  (shown in broken lines in  FIG. 4 ) which is orientated towards another adjacent seat  32 . In order to remove any ambiguity,  FIG. 4  indicates the tray  9  in two separate positions which it cannot occupy simultaneously, and not a single tray of complex form. 
     The positioning of a tray  9  in a deployed position on the folded backrest  3 , starting from the position thereof stored at the rear of the backrest  3 , follows the following steps. Pressure on the activation push-button  20  releases the tray  9 , which is withdrawn from the recess  12  by said tray  9  being pivoted about the two lobes  26  thereof placed in the indentation  14  of said recess  12 . The tray  9  is brought above the two aligned grooves  28  correspond to the desired position. Pressure on the secondary push-button  29  releases the grooves  28  and the tray  9  is introduced into said grooves  28  in the region of the two lobes  26  thereof. Releasing the secondary push-button  29  allows the tray  9  to be locked in the grooves  28  by means of the biasing elements which apply a pressure against the tray  9 . In order to move the tray  9  from its deployed position to its stored position, a pressure on the secondary push-button  29  releases the grooves  28  and the tray  9  can then be withdrawn from said grooves  28 . The tray  9  is then inserted in the recess of the receiving frame  11  by first introducing the two lobes  26  thereof into the indentation  14 . The tray  9  is then subjected to a rotation in order to be brought into contact with the base of the recess  12 . Simultaneously, a pressure on the activation push-button  20  releases the locking mechanism in order to allow the complete insertion of the tray  9  into the recess  12 . The pressure on said push-button  20  is then released in order to lock the tray  9  in its storage position behind the backrest  3 .