Abstract:
A headrest includes a support structure adjustable in height of an actuator and defining a curved surface the convex side of which faces upwards, a pad fixed to the backrest at the front and slidable on the curved surface, and having a rear portion arranged for sliding vertically adjacent the rear of the backrest during the adjustment movement, and a guide device for guiding the rear portion of the pad and keeping it oriented parallel to the backrest.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a headrest of adjustable height for a motor-vehicle seat. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide an improved headrest of adjustable height which is functional and aesthetically pleasing. 
     This object is achieved, according to the present invention, by a headrest comprising a substantially rigid support structure defining a curved surface the convex side of which faces upwards, along the profile of a headrest, actuating means for raising and lowering the support structure along an axis substantially parallel to the backrest of the seat, a pad element superimposed for sliding on the curved surface and having a front portion which can be fixed to the backrest and a rear portion arranged for sliding vertically adjacent the rear of the backrest during the adjustment movement between the said positions, and a guide device associated with the rear position of the pad element for guiding the rear portion and keeping oriented along an axis substantially parallel to the backrest. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The structural and functional features and the advantages of a preferred embodiment of the headrest according to the present invention will become clear in the course of the following detailed description, given with reference to the appended drawings, provided purely by way of non-limiting example, in which: 
     FIG. 1 is a longitudinal, vertical section of a headrest according to the invention, fitted on the backrest of a motor-vehicle seat, and 
     FIG. 2 is a view similar to FIG. 1 showing the headrest in section, in a raised position relative to that of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference initially to FIG. 1, the backrest of a motor-vehicle seat, indicated  10 , has a front surface  10   a  and a rear surface lob which are substantially vertical. 
     A headrest according to the present invention, generally indicated  11 , is mounted on top of the backrest  10 . The headrest  11  comprises a substantially rigid structure  12 , including a substantially vertical rod  13  fixed at its top to a rigid support element  14  arranged around the periphery of the top of the backrest and defining a surface  15  having a substantially inverted J-shape extending in the direction perpendicular to that of the drawing in FIG.  1 . 
     The surface  15 , which is curved with its convex side facing upwards, constitutes a support and sliding surface for a pad element  16  of soft and flexible material formed substantially in the shape of a saddle completely covering the support element  14 . The pad  16  has a front portion  16   a  fixed to the backrest  10  of the seat by means of a fixing element  17 , an upper, central portion  16   b  superimposed on and in contact with the curved surface  15 , and a rear portion  16   c  which extends downwards, covering the upper portion of the rear surface  10   b  of the backrest. 
     The vertical rod-like element  13  can translate vertically by means of an actuator  18 , for example, an electrical actuator, and is guided in its vertical movement by a guide  19  disposed inside the backrest and fixed to the structure thereof. 
     The terms “vertical”, “raised”, and “lowered” are intended to refer herein to the plane in which the backrest  10  of the seat lies, upon the understanding that the backrest may be reclinable and may therefore adopt an orientation other than vertical. 
     In the preferred embodiment shown in the drawings, the guide element  19  for the rod  13  forms, at the front, a lug  19   a  which projects forwards towards the front surface  10   a  of the backrest to constitute an anchorage for the fixing element  17  which secures the front edge portion  16   a  of the pad element  16 . 
     By activating the electrical actuator  18 , it is possible to raise and lower the structure  12  and the pad  16 , changing from the position of FIG. 1 in which the headrest is lowered, to the position of FIG. 2 in which the headrest is raised, and vice versa, the structure  12  preferably being able to reach and stop at a plurality of intermediate heights between those described herein as the fully lowered position (FIG. 1) and the fully raised position (FIG.  2 ). 
     As stated, in longitudinal section, the rigid element  14  has an inverted J-shape the rear portion of which extends downwards for a greater distance than the front portion. The rigid element  14  is preferably formed by a body of rigid material (for example, of sheet metal), the substantially vertical rear portion  14   c  of which is integral with or fixed firmly to a vertical guide means, schematically indicated  20 . 
     In an alternative embodiment (not shown), the vertical guide  20  may be formed by a vertical slot formed in the element  14 . 
     In any case, the guide means  20  will be formed in a manner such as to permit the engagement for vertical sliding of a rear sliding block  21 , fixed to the rear pad portion  16   c  or, as shown, incorporated within it. 
     The sliding block  21  is also connected at  21   a  to a resiliently deformable element  22  which, together with the guide  20  and the sliding block  21 , constitutes a device which serves to guide the rear portion  16   c  of the pad vertically along an axis substantially parallel to that of the backrest  10 , in particular, of the rear surface  10   b  of the backrest. 
     The resilient element  22  which, in the embodiment illustrated, is a gas spring, has an upper end  22   a  fixed to the top of the guide  20  or to the portion  14   c  of the element  14  and a lower end  22   b  fixed to the sliding block  21 . 
     The sliding block  21  carries a substantially flat element  23  which projects downwardly, parallel to the rear lob of the backrest, and which is incorporated in the rear portion  16   c  of the pad, extending as far as the lower end region of this portion. 
     The headrest according to the invention operates as follows. 
     In order to raise the headrest  11  and thus to change from the configuration shown in FIG. 1 to that shown in FIG. 2, the electric motor  18  is activated by means of a control disposed in a remote position (not shown), causing the rod  13  to be raised vertically as indicated by the arrow A in FIG.  1 . During this stage, the pad  16 , which is anchored to the seat at  17  at the front, slides along the arcuate surface  15  as indicated by the arrow B in FIG.  1 . During this movement, the sliding block  21  is pulled upwards, together with the rear portion  16   c  of the pad, and slides in the guide  20 , compressing the resilient element  22 , in opposition to the resilient force thereof. 
     The configuration shown in FIG. 2, in which the headrest  11  is raised, is thus reached. In order to lower the headrest, the electric motor  18  is operated in the opposite direction so as to cause the rod  13  to move downwards in the direction indicated by the arrow C in FIG.  2 . The pad  16  tends to slide, moving anticlockwise (in its upper portion  16   b ) on the curved surface  15 , as indicated by the arrow D; during this stage, the resilient element  22  is free to extend, thus urging downwards its own lower end  22   b , which is guided by the sliding block  21  that slides along the guide  20 . 
     Whilst this movement is taking place, as will be appreciated, the elements  20 ,  21 ,  22  and  23  cooperate to prevent the portion  16   c  from sticking during its downward movement and guide it downwards, keeping it adjacent the rear side  10   b  of the backrest. 
     The pad  16  is preferably wrapped in a covering (not shown) of material suitable for limiting the friction between the pad and the curved surface  15  to low values. 
     It will be noted that the rear edge portion  16   c  of the pad covers the upper portion of the rear  10   b  of the backrest (FIG. 2) even when the headrest is in the fully raised position.