TIP-UP SEAT, PARTICULARLY FOR MOTOR VEHICLES

Abstract: On each side of the seat (1), in addition to a first arm (5) which supports the rear region of the seat (1) so that the seat can be adjusted in a fore-and-aft direction, there is provided at least one second arm (16) which is hinged to the lower end (6) of the first arm (5) and is pivotable in its turn about a respective centre of rotation (17) situated in a generally raised position relative to the plane of the floor of the passenger compartment. Disengagement of a hook element (19) which holds the lower end (6) of the first arm (5) in a position near the floor of the passenger compartment makes it possible to cause a generally upward movement of this lower end (6), resulting in a forward tipping of the seat.

Description: The present invention relates in general to automobile seats and particularly concerns a seat including at least one first arm for supporting the rear region of the seat on the floor of the passenger compartment, the first arm being pivotable about its lower end which is held in a position near the floor of the passenger compartment to allow the seat to be moved in a fore-and-aft direction relative to the passenger compartment. A seat of this type is described, for example, in DE-A-2 032 147, as well as in European Patent Applications EP-A-0 232 687, EP-A-0 248 773 and EP-A-0 288 439, in the name of the same Applicant, the two latter documents being only within the meaning of Art. 54 (3) EPC. The object of the present invention is to produce a seat which, taking the solutions described in the above-mentioned previous applications as a starting point, enables the following requirements to be satisfied in an optimal manner: maximum simplification of the structure of the seat and the system of movement (fore-and-aft adjustment and forward tipping), maximum freedom of movement for the lower limbs of the passengers seated on the rear bench seat when the seat is used as a front seat, the use, for the fore-and-aft adjustment, of a system of movement which operates along a path that achieves improved height adjustment for persons of different heights, and the achievement of the maximum possible forward tipping movement, so as to facilitate entry and exit of the occupants of the rear seat of the motor vehicle. According to the present invention, this object is achieved by virtue of a seat of the above-specified type, characterised in that it includes at least one second arm which is hinged to the lower end of the first arm and is pivotable in its turn about a respective centre of rotation situated in a position generally higher than the position near the floor of the passenger compartment to enable a general upward movement of the lower end of the first arm from the position near the floor of the passenger compartment, with a consequent forward tipping of the seat. The invention will now be described, purely by way of non-limiting example, with reference to the appended drawings, in which: Figure 1 is a first side elevational view of a seat according to the invention, Figure 2 shows a variant of the seat of Figure 1, Figure 3 shows, with specific reference to the embodiment illustrated in Figure 2, the criteria, common also to the embodiment of Figure 1, according to which the seat according to the invention is tipped forwards, and Figure 4 shows a possible further variant of the seat of Figure 2. In the drawings, an automobile seat is generally indicated 1 and is intended preferably to be used as the front seat of a car. Within the seat 1 there can generally be distinguished a horizontal sitting portion or squab 2 and a vertical portion or backrest 3 of which only the lower part is visible in the drawings. An adjustment mechanism 4 of known type is interposed between the squab 2 and the backrest 3 and enables the position of the backrest 3 relative to the squab 2 to be varied selectively, particularly as far as its inclination is concerned. The seat 1 is supported on the floor P of the passenger compartment of the vehicle (not illustrated in its entirety) astride a load-bearing structure, such as a rib or stiffening cross member T, which projects upwardly from the general plane of the floor P. The seat 1 is supported on the floor P by an assembly of support elements which act in correspondence with the front end and the rear end of the squab 2. In general, the terms "front", "rear", "lower" and "upper", as used in the present description and in the claims which follow, should be understood as referring to the normal position of mounting of the seat 1 in the motor vehicle. As further background information, it should be noted that the elements supporting the seat 1 on the floor P are generally symmetrical on the two sides of the seat; for this reason, explicit reference will only be made to the support elements on one side of the seat (specifically the left side) in the following detailed description, it being understood that, at least in the embodiments to which the present description relates, similar support elements are present on the other side of the seat. In all the embodiments illustrated in the drawings, the rear end of the squab 2 is supported by an arm 5 having a lower end 6 pivotably hinged about a horizontal axis to a bracket 7 which, in the normal condition of use of the seat, rests on the floor P. At its upper end, the arm 5 is connected to the seat 1 at an articulation point 8 usually defined by a pin which projects outwardly of the rear end of the squab 2. In the embodiments illustrated in Figures 1 and 2, the connection between the arm 5 and the squab 2 is achieved through an adjustment element 9 (of known and commercially available type) which enables the angle assumed by the arm 5 relative to the seat unit 1 to be varied selectively (for example, by the operation of an adjustment knob). Since the arm 5 can pivot about its lower end 6 resting on the floor P, the above adjustability is translated into the possibility of selective variation of the longitudinal position assumed by the seat 1 relative to the passenger compartment. The user may thus adapt the seat to his own anthropometric characteristics and to his own driving and travelling habits. According to a known solution, since the lower end 6 of the arm 5 is situated in a position generally forward of the rear region of the seat 1 (point 8), the upper end of the arm 5 causes the rear region to move along a circular path during pivoting of the arm 5, so that this rear region is raised or lowered respectively during forward and backward adjustment movements. In this way, it is possible to keep the line of sight of the person occupying the seat approximately constant, regardless of his stature. In the embodiment illustrated in Figure 1, the squab 2 is supported at its front end by runners 10 which are slidable within respective guides 11 extending generally longitudinally of the passenger compartment. The guides 11 are mounted on the top of the cross member T by means of hinge elements with horizontal axes 12 which enable the guides 11 to be oriented so as to follow the runners 10 during their movement resulting from displacement of the seat 1 in a fore-and-aft direction relative to the passenger compartment. The movement of the runners 10 is in fact a combined translational and rotational movement due to the fact that the rear end of the squab 2, guided by the arm 5, describes, as can be seen, a circular path. In the variant illustrated in Figure 2, the assembly constituted by the runners 10 and the guides 11 is replaced by a further pivoting arm 13 (one for each side of the seat) having a lower end 14 hinged to the floor P of the passenger compartment and an upper end 15 hinged to the squab at the front end thereof. In Figures 1 and 2, the broken lines schematically indicate the position of maximum advance reached by the arm 5 and the plate 10 (Figure 1) or the arm 13 (Figure 2) during longitudinal adjustment of the seat from the most rearward position which is that shown by continuous lines in the same drawings. The arm 5 is generally arcuate in shape with its concavity facing towards the rear of the passenger compartment: this solution, together with the positioning of the lower end 6 in an approximately central position relative to the length of the seat 1, means that the arm 5 gives maximum freedom of movement for the lower limbs of the passengers occupying the rear seat of the passenger compartment. In both the solutions illustrated in Figures 1 and 2, the bracket 7 to which the arm 5 is hinged constitutes the lower end of a further arm 16 whose upper end 17 is itself hinged (for pivoting about a horizontal axis) to a support 18 fixed to the cross member T adjacent its top. The pivoting arm 16 (here again, one for each side of the seat 1) is therefore able to pivot about a respective centre of rotation (hinge 17) which is in a position generally higher than and forward of the position occupied by the bracket 7 in the normal condition of use of the set described above. A hook element 19 which can be operated by means of a lever or similar transmission element (not illustrated) locks - in its closed position - the arm 16 against the cross member T, keeping the bracket 7 in a position resting on the floor P of the passenger compartment. In these conditions (which are those adopted when the vehicle is moving) it is possible to adjust the longitudinal position of the seat 1 selectively between the end positions shown by continuous lines and broken lines in Figures 1 and 2 by operating the device 9 which adjusts the angle of the arm 5 relative to the seat 1 as a whole. When the hook element 19 is brought into the disengaged position, however, the bracket 7 and the arm 16 as a whole are left free and the seat may be tipped forwards towards the forward position shown by chain lines in Figure 3. Since the bracket 7 is no longer held by the hook element 19, the arm 16 is in fact free to pivot upwardly about the hinge 17, enabling the raising of its lower end (bracket 7) and the general forward translation of the arm 5 and the seat 1 as a whole. In this way, the seat may be moved forwards into a position in which the greater part of its bulk is in fact positioned forward of the cross member T. Entry to and exit from the passenger compartment by the passengers occupying the rear seat is thus easy. This result is obtained by virtue of the upward movement of the lower end 7 of the arm 16 from its position very near to the floor P, used in normal running conditions. The seat 1 can then be moved back towards its normal position of use by tipping it backwards, causing a consequent downward pivoting of the arm 16 until the bracket 7 is brought into the position in which it is engaged by the element 19. The variant illustrated in Figure 2 has a further advantage with respect to the solution illustrated in Figure 1 (runners 10 and guides 11), due to the fact that the seat may tipped forwards while the angle of the arm 5 relative to the squab 2 and the backrest 3 is kept constant: this means that the seat retains its adjustment position, preselected by operation of the device 9, whilst it is being tipped forwards. The further variant illustrated in Figure 4 differs from the solution illustrated in Figure 2 in that the upper end 8 of the arm 5 is freely hinged to the rear region of the squab 2, while the longitudinal adjustment device (indicated 29 in Figure 4) is transferred to the upper end 15 of the front arm 13. This solution can have advantages from the functional point of view, in that the knob for longitudinal adjustment of the seat is positioned near the front edge of the squab 2 in a position which is easily reached by the passenger, and, furthermore, is moved away from the other adjustment devices (knob 4) which enable the inclination of the backrest 3 to be adjusted.

Claims: 1. A vehicle seat comprising at least one first arm (5) for supporting the rear region of the seat (1) on the floor of the passenger compartment (P), the first arm being pivotable about its lower end (6) which is held in a position near the floor of the passenger compartment (Figure 1, Figure 2) to enable the seat (1) to be moved in a fore-and-aft direction relative to the passenger compartment, characterised in that it includes at least one second arm (16) hinged to the lower end (6) of the first arm (5) and pivotable in its turn about a respective centre of rotation (17) situated in a position generally higher than the position near the floor of the passenger compartment to enable a general upward movement of the lower end (6, 7) of the first arm (5) from the position near the floor of the passenger compartment (P), with a consequent forward tipping of the seat (1). 2. A seat according to Claim 1, which can be mounted on the floor of the passenger compartment (P) adjacent a load-bearing structure (T) projecting from the floor (P), characterised in that the respective centre of rotation (17) of the second arm is situated on the load-bearing structure (T). 3. A seat according to Claim 1 or Claim 2, characterised in that the respective centre of rotation is situated forward of the position near the floor of the passenger compartment (P). 4. A seat according to any one of Claims 1 to 3, characterised in that the first arm (5) extends along a curve with its concavity facing towards the rear part of the passenger compartment. 5. A seat according to any one of the preceding claims, characterised in that it includes hook means (19) acting between the floor of the passenger compartment (P) and the lower end (6) of the first arm (5) to prevent the general upward movement of the lower end (6) from its position near the floor of the passenger compartment (P). 6. A seat according to any one of the preceding claims, characterised in that it includes a first arm (5) and a second arm (16) for each side of the seat. 7. A seat according to Claim 1, characterised in that it includes, for supporting the front end of the seat (1), at least one guide (11) which has a generally horizontal development and defines the path of movement of the front end of the seat (1). 8. A seat according to Claim 7, characterised in that the at least one guide carries associated hinge means (12) which enable it to be oriented about a horizontal axis. 9. A seat according to Claim 2 and either of Claims 7 and 8, characterised in that the at least one guide (11) is mounted on the load-bearing structure (T). 10. A seat according to any one of the preceding Claims 1 to 6, characterised in that it includes at least one pivotable third arm (13) for supporting the front region of the seat (1) on the floor of the passenger compartment (P). 11. A seat according to any one of Claims 1 to 6, characterised in that the first arm (5) carries an associated adjustment device (9) for selectively varying the angle of the first arm (5) relative to the seat (1). 12. A seat according to Claim 10, characterised in that the third arm carries an associated adjustment device (29) for selectively varying the angle of the third arm (13) relative to the seat (1) while the first arm (5) is connected to the seat (1) and can pivot freely relative thereto.

Inventors: DAL MONTE, ANTONIO
Applicants: FIAT AUTO S.P.A.
Application year: 1988
Main classification: B60N2
IPC codes: B60N2