A seat for vehicles, particularly motor cars

Abstract: The squab (2) of the seat is supported at its front and rear regions (5) and (6) by respective support arms (10, 11). The lower ends (X₁₀′, X₁₁′) of the arms (10, 11) are mounted on the free ends of respective pivoted elements (14, 15) whose positions are adjustable selectively so as to enable the seat (1) to be adjusted more precisely to the anthropometric characteristics of its occupant, the whole considerably reducing the vertical bulk of the squab (2) and of the seat (1) as a whole.

Description: The present invention relates to seats for vehicles, for example motor cars, and relates particularly to a seat having the characteristics quoted in the preamble to Claim 1 below. Such a seat is known, e.g. from US-A- 3 037 735. Somewhat similar seats are widely known in the art, for example from European patent application No. EP-A- 0 310 572 in the name of the same Applicant. Likewise known (for example from Italian Patent No. 1 218 954, also in the name of the Applicant) are seats which, together with an adjustment movement generally longitudinally of the passenger compartment of the motor vehicle, can perform a simultaneous lowering-raising movement which affects the squab as a whole either uniformly, or differently at the front and rear ends of the squab. This movement is accompanied by a coordinated movement of the backrest which, simultaneously or alternatively depending on the specific requirements of use, provides a series of advantages, such as: maintaining the line of sight of the person occupying the seat at an almost constant level, whatever the longitudinal position of adjustment of the seat, varying the length of the seat surface of the squab and consequently avoiding problems such as that currently known as "suspended limb" or inadequate support of the thighs of the seat occupant, and correctly supporting the back of the seat occupant, particularly as regards the lumbosacral region. Naturally, the adaption of the seat to the anthropometric characteristics and/or tastes of the seat occupant can be made more precise the greater the ability of the various elements forming the seat to move separately. Increases in the possible separate movements of the seat parts can, however, create confusion, particularly for people who do not have a good spatial sense and who have a particular sensitivity to their own body mechanics, and who form the large majority of the motoring population. Moreover, the need to provide a seat which can be adapted precisely to the characteristics and tastes of the occupant conflicts, to a certain extent, with the need to reduce its overall bulk. This need is particularly marked in sports cars, especially those of high class and performance. The floors of the passenger compartments of such cars usually have rather uneven structures due to the presence of stiffening ribs, cross members, etc. The object of the present invention is to provide a seat of the type specified above which, whilst retaining excellent adaptability to the characteristics and tastes of the occupant, has, on the one hand, a considerably reduced vertical bulk (thickness of the squab and of the elements associated therewith), particularly as regards the lowering of the so-called H point, and which, at the same time, avoids giving rise to confusion due to the presence of an excessively complicated adjustment system. According to the present invention, this object is achieved by virtue of a seat which has the further characteristics quoted specifically in the characterising portion of Claim 1. The Applicant has found that a seat according to the invention enables the so-called H-point to be lowered by approximately 10 cm when the reduction in the vertical bulk of the squab-adjustment mechanism resulting from the main characteristics of the invention is accompanied by the use, for the production of the squab itself, of a thin layered (multi-layer) structure, for example of the type described in the previous European patent application No. EP-A- 0 363 330 in the name of the same Applicant. Moreover, the reduction in the vertical bulk is achieved whilst the original floor space is completely retained (in an Alfa Romeo 164 motor car, in a solution found particularly advantageous) and with the use of the same fixing points for the seat as are used in cars currently produced. The use of a seat according to the invention has been found particularly advantageous both for the driver of the motor vehicle and for the passenger who sits beside the driver. This is due, in particular, to the fact that the passenger is offered the ability to raise the front end of the squab quite considerably until a particularly agreeable and relaxing position is reached. Essentially, the solution according to the invention provides the possibility of a coordinated longitudinal and vertical movement of the squab (and of the backrest) of the seat such as to enable the seat occupant to effect an initial, rough adjustment of the attitude of the seat so as to bring it closer to his own anthropometric characteristics and driving or travelling tastes. When this initial adjustment has been made, two fine-adjustment controls can then be operated so as to vary the positions of the front edge and of the rear edge of the squab until a completely satisfactory adjusted position is reached. The backrest preferably moves on a conventional slide structure whose strengthin stress tests is well known. The solution according to the invention is also favourable as regards the insertion of the feet of the persons occupying the rear seats, even transversely, which facilitates their getting into and out of the vehicle. The invention will now be described, purely by way of non-limiting example, with reference to the appended drawing, which comprises a single figure showing a seat according to the invention in side elevation in two possible positions of adjustment. In the drawing, a motor-vehicle seat (for example the driver's seat of a motor car) is generally indicated 1 and is intended for fixing to the floor P of the motor vehicle (not shown as a whole) and comprises essentially three elements, that is to say: a generally horizontal seat element 2 defined below for brevity as the "squab", a backrest 3 for supporting the back of the seat occupant, and a headrest element 4 situated at the upper end of the backrest 3. In general, the squab 2 can be seen to include a front region 5 and a rear region 6, the terms "front" and "rear" referring to the normal direction of travel of the motor vehicle. In order to fix the seat 1 to the floor P of the passenger compartment, the provision is generally envisaged of two parallel guides 7 (only one of which is visible in the drawings) which are fixed to the floor P, for example to a pair of transverse ribs T₁, T₂ thereof, so as to extend approximately horizontally, usually with their front ends located in higher positions than their rear ends. Two side plates 8 (of which, again, only one is visible in the drawing, that is the one situated on the left hand side of the seat 1) are slidably mounted on the guides 7 and extend generally upwardly and rearwardly so as to form support arms proper for the lower end of the backrest 3. An articulation and adjustment mechanism 9 (of known type) is situated between the free end of the plate 8 and the lower end of the backrest 3 and enables a general adjustment movement to be imparted selectively to the backrest 3 to make it pivot forwards and backwards about a respective axis X₉ which is horizontal in the arrangement of use and is defined by the mechanism 9. The front region 5 and the rear region 6 of the squab 2 are supported by respective pairs of support arms 10 and 11. Again, only the support arms located on the left hand side of the seat are visible in the drawing. The arms 10 and 11 are articulated to the squab 2 at their upper ends at points which are generally fixed relative to the squab 2. More precisely, the upper ends of the front arms 10 are articulated to the squab 2 about a horizontal axis X₁₀ whilst the upper ends of the rear arms 11 are articulated to the squab about a respective horizontal axis X₁₁. In correspondence with the latter axis, the upper ends of the arms 11 have respective pins 12 slidably engaged in slots 13 provided in the corresponding plates 8. The slot 13 extends in a generally straight line from a front end to a rear end in a generally inclined arrangement with its front end located in a lower position than its rear end. The pin 12 and the slot 13 thus constitute ramp coupling means which, when the plates 8 are slid along the guides 7 to adjust the longitudinal position of the backrest 3 (after the release of locking means - not shown - which hold the seat 1 in a fixed position in the normal conditions of use), cause the rear region 6 of the squab 2 to move vertically as well as causing a general forward-rearward translational movement relative to the passenger compartment. More precisely, when the backrest 3 is pushed forwards, the squab 2 also moves forwards with a general pivoting and translational movement which causes the rear region 6 to rise towards the lower end of the backrest 3 (see the broken outline in the drawing). In a complementary manner, when the backrest 3 is moved backwards again, the squab 2 also moves back, simultaneously performing a rearward tilting movement which lowers the rear region 6 relative to the backrest 3. This combined translational-pivoting movement of the squab 2 is intended to enable the seat to be adapted more precisely to the anthropometric characteristics of its occupant. In particular, when the seat 1 is moved forwards (for example to accommodate a small driver or passenger) the raising of the rear region 6 of the squab enables the line of sight of the seat occupant to be kept approximately unaltered. Conversely, in the case of a tall person, the rearward movement of the seat 1 also involves a lowering of its rear region 6. The line of sight is therefore also substantially maintained in this case. Moreover, the vertical adjustment of the rear region 6 of the squab 2 relative to the backrest 3 ensures adequate support for the lumbosacral region of the seat occupant in all cases. As already stated, the squab 2 is preferably made with a generally layered structure of the type described in European patent application No. EP-A- 0 363 330 in the name of the same Applicant. The translational-height variation movement of the rear region 6 of the squab 2 is caused by the pivoting of the arms 11 about a respective lower articulation axis X₁₁', whose position is variable selectively according to criteria which will be described more fully below. The movement of the front region 5 of the squab 2 which results from the general translation of the seat is also guided by the pivoting of the arms 10 about a lower articulation axis X₁₀'. The position of this latter axis is also adjustable selectively according to criteria which will be described more fully below. In general, the rear arms 11 are oriented with their lower articulation axis X₁₁' located in a position considerably further forward than their upper articulation axis X₁₁, whatever the position of adjustment of the seat. The front arms 10 also have a substantially similar orientation, with the lower articulation axis X₁₀' located in a position further forward than the upper articulation axis X₁₀. The general orientation of the front arms 10, however, is closer to the vertical. This means that, during the overall adjustment movement for a given position of the lower articulation axis X₁₀' - the front region 5 of the squab retains an almost constant height. The lower articulation axes X₁₀' and X₁₁' of the arms 10 and 11 are defined by respective pivots which connect the arms 10 and 11 to respective further front and rear adjustment elements or arms 14 and 15. These adjustment elements are articulated at their opposite ends (their upper ends in normal conditions of use) to respective support elements which are movable along the guides 7. For example, the front adjustment arms 14 are mounted each at the vertex (the lower vertex in use) of a flange or bracket 16 of an element which is movable along the guide 7. A similar mounting arrangement is adopted for the rear adjustment arms 15, by means of their connection to a support element not specifically shown in the figures. The adjustment arms 14 and 15 are thus inclined generally downwardly and can pivot about respective axes X₁₄ and X₁₅ which are horizontal in use. The arms 14 and 15 are pivoted selectively about the axes X₁₄ and X₁₅ by drive means which are not shown specifically in the drawings since they are of known type. They may, for example, be electric motors or may be fluid-operated, or may even be operated mechanically by the seat occupant rotating corresponding control knobs or handles projecting from the sides of the seat. In any case, the function of the adjustment arms 14, 15 is, essentially, to vary the pivoted portions of the lower ends of the arms 10, 11 as a result of their pivoting movement. In other words, by the selective pivoting of the adjustment arms 14, 15 it is possible to vary correspondingly the positions of the axes X₁₀' and X₁₁' about which the arms 10 and 11 pivot. In effect, the pivoting of the adjustment arms 14 and 15 achieves a fine adjustment of the position assumed by the front region 5 and the rear region 6 of the squab 2, as shown schematically in chain line and in broken and crossed lines in the drawing. In particular, the shaded area indicated A indicates the set of adjustment positions of the axis X₁₀ which can be achieved by the pivoting of the arm 10 and of the arm 14. The person occupying the seat according to the invention can consequently adapt the seat to his requirements by means of two successive adjustments: a first adjustment, which may be defined as a rough adjustment and is achieved by the movement of the seat 1 as a whole forwards and backwards, giving rise to the translational movement of the backrest 3 and to the corresponding translational-pivoting movement of the squab 2 described above, and a second, fine adjustment, achieved by means of the controls which pivot the adjustment arms 14 and 15 so as to vary the height (and more generally the position) of the front region 5 and the rear region 6 of the squab 2. This is all achieved within a structure which, particularly as regards the squab 2, is extremely compact. In fact, it will be noted that the direction in which the adjustment arms 14, 15 extend relative to their main point of fixing to the structure of the vehicle (identified by the axes X₁₄ and X₁₅) is generally opposite the direction in which the corresponding pivot arms 10, 11 extend. In fact the adjustment arms 14, 15 extend downwardly from this point whilst the arms 10 and 11 which support the squab 2 extend upwardly in a generally V-shaped configuration. This solution is found to be particularly advantageous in cases in which, as in the embodiment illustrated, the floor P of the passenger compartment is uneven as a result of the presence of stiffening formations such as the cross members T₁ and T₂. The invention in fact provides a structure for supporting and adjusting the squab (the arms 10, 11 and 14, 15) which fits, so to speak, between the cross members. This, together with the use of a thin, multilayer structure for the squab 2, enables the vertical bulk of the squab 2 to be minimised.

Claims: A vehicle seat comprising a squab (2) with a front region (5) and a rear region (6) and respective associated, selectively-pivotable support arms (10, 11) articulated at their upper ends (X₁₀, X₁₁) to the squab (2) and a backrest (3) which rises from the rear region (6) of the squab (2), wherein the support arms (10, 11) are articulated at their lower ends (X₁₀', X₁₁') to respective adjustment elements (14, 15) which can be pivoted selectively in order selectively to vary the position of the lower articulation (X₁₀', X₁₁') of the support arms (10, 11), and wherein the adjustment elements (14, 15) are also constituted by arms which extend substantially in the opposite direction from the support arms (10, 11) , in a generally V-shaped configuration, characterised in that the backrest (3) is provided at its lower end with support means (8) which can perform a generally translational movement (7) forwards and backwards relative to the vehicle, and in that the support means (8) for the backrest (3) are coupled, with the interposition of ramp means (12, 13), to at least one support arm (11) which is articulated (X₁₁) to the rear region (6) of the squab (2) in an arrangement such that the forward-rearward movement of the support means (8) of the backrest (3) causes a vertical translation of the rear region (6) of the squab (2) as well as a corresponding forward-rearward movement of the squab (2). A seat according to Claim 1, characterised in that the ramp means comprise a pin (12) and a slot (13) arranged respectively on one and on the other of the at least one support arm (11) and the support means (8) for the backrest (3). A seat according to Claim 2, characterised in that the slot (13) is provided in the support means (8) for the backrest (3) and extends in a generally inclined arrangement with its front end located in a generally lower position than its rear end. A seat according to any one of the preceding claims, characterised in that it includes at least one support arm (11) which is articulated to the rear region (6) of the squab (2) and, in all possible positions of use, is arranged with its lower articulation point (X₁₁') in a generally lower position than its upper point (X₁₁) of articulation to the squab (2). A seat according to any of the preceding claims, characterised in that it includes at least one support arm (10) which is articulated (X₁₀) to the front region (5) of the squab (2) and, in all possible positions of use, is arranged with its lower articulation point (X₁₀') located in a generally lower position than its upper articulation point (X₁₀). A seat according to Claim and Claim 4 and Claim 5, characterised in that, in all possible positions of adjustment, the at least one front support arm (10) is inclined at a generally smaller angle to the vertical than the at least one rear support arm (11). A seat according to any one of the preceding claims, characterised in that the adjustment elements (14, 15) have associated drive means selected from the group consisting of electrical operating means, fluid operating means and mechanical adjustment means. A seat according to any one of the preceding claims, characterised in that the squab (2) has a thin, generally-layered structure.

Inventors: DAL MONTE ANTONIO, DAL MONTE, ANTONIO
Applicants: FIAT AUTO SPA, FIAT AUTO S.P.A.
Application year: 1990
Main classification: B60N2
IPC codes: B60N2