Seat for vehicles, such as go-karts

Abstract: The seat comprises a shell structure (2) which is rigid, as a whole, and, on that side intended to receive the driver's body, there are one or more inflatable cushions (4a, 5a). The possibility of varying the inflation pressure of the cushions (4a, 5a) selectively during movement of the vehicle is also envisaged.

Description: The present invention relates to seats for vehicles. The invention has been developed with particular concern for its possible application to sports vehicles such as go-karts and the like. This field of application (to which explicit reference will be made below in the present description although this should not be interpreted as limiting the scope of the invention in any sense) has always had a tendency to use simple bodies and shells of rigid material for the seats. This is as much for practical reasons (to minimise weight) as for a wish to make the vehicle simple and spartan in view of its function as a competitive vehicle. With the continuous improvements in the performance of such vehicles there is, however, a corresponding increase in the forces experienced by the driver's body as a result of accelerations, with the consequent possibility that the performance may be limited. In the context described above the use of solutions which are already known in the field of conventional motor-vehicle seats (for example quantities of padding of various types, with associated spring elements, etc.) does not provide an answer to the problems stated above. Usually these conventional solutions require the adoption of more or less fixed structures which are just as difficult to adapt to the different anthropometric characteristics and/or habits of the individual sportsman as to the different conditions of movement. The object of the present invention is to provide a solution to the requirements indicated above while overcoming the limitations intrinsic in prior art solutions. In that respect, the invention, having the characteristics claimed specifically in Claim 1, takes advantage of some features which - per se - are known from different fields. For instance GB-A-1 405 333 discloses a seat for use in a vehicle simulator comprising a user receiving structure which, as a whole, is rigid and has a surface which can receive at least a part of a user's body, said seat having at least one selectively inflatable cushion which, in use, can be interposed between the structure and the user's body. The same document also shows two opposite sides for said structure which are provided with at least two inflatable cushions, one against each of the sides, as well as a backrest included in said structure with a respective upper end and at least one inflatable cushion provided at the upper end. Finally, GB-A-1 405 333 refers to the possibility of governing seat "hardness" and "softness" to simulate e.g. an acceleration cue directed from buttocks toward head. The invention will now be described, purely by way of non-limitative example, with reference to the appended drawings, in which; Figure 1 is a general perspective view of a seat according to the invention, and Figure 2 shows a system for the automatic control of the characteristics of a seat according to the invention with reference to a currently preferred embodiment. In the drawings a vehicle seat is generally indicated 1. In the specific embodiment, one is concerned with a seat for a motorised sports vehicle such as a go-kart; other fields of application can however be envisaged. In accordance with a known solution, the seat 1 comprises a shell 2 of a material such as a light metal or, more preferably, a structural synthetic material such as glass-fibre reinforced resin, plastics material, etc., defining a shell-shaped structure which, as a whole, is rigid and can be fixed (according to well known criteria) to the vehicle body shown schematically in Figure 1 in the form of several tubes which make up the frame of a go-kart (not illustrated in its entirety) . The definition of the structure of the shell 2 as being ``as a whole" rigid is intended to indicate that this structure may possibly include more or less flexible parts. What matters, however, is that this structure is rigid overall so that its concave side, which faces upwardly in use, can receive at least part (typically most of the trunk and proximal portions of the lower limbs) of the body of a passenger (such as, for example, the driver of a go-kart). The shell 2 is shaped so that the seat 1 has a seat proper 3, a backrest 4 and two sides 5 shaped so as to give the seat 3 and the backrest 4 a generally channel shape so as effectively to contain the driver's body laterally. The shell 2 thus defines overall, a shell shape with a concave inner surface which can receive at least part of the user's body. In a preferred solution (also known per se) the seat 3 also has two front appendages 3a which project forwardly so as to provide good support for the popliteal region of the driver's legs. The solution of covering at least the inner surface of the shell 2 intended to receive the driver with a covering of a material such as "alcantara" is already known. This is as much for aesthetic reasons as for providing a certain degree of friction with the driver's body so as to prevent this from slipping on the seat, particularly due to accelerative forces which arise during movement of the vehicle. A salient characteristic of the solution of the invention is the provision of at least one selectively inflatable cushion element in that region of the seat intended to be between the shell 2 and the driver's body (that is, on the inner surface of the shell 2), the cushion being inflatable by a fluid, preferably a gas. In the currently preferred embodiment, three cushion elements of this type are provided. More precisely, two cushions 5a are located one against the upper part of each of the sides 5 (thus on the sides of the backrest 4) and a third cushion 4a extends horizontally along the upper part of the backrest 4. Preferably the cushions 4a, 5a (constituted for example by inflatable pads made of a material such as that used for the inner tubes of tyres) are interposed between the shell 2 and the cover 2a. This arrangement explains the presence of one or more holes 6 in those parts of the cover itself which cover the cushions: the purpose of the holes 6 is to allow air to pass through the cover 2a, avoiding the formation of "free" air cushions, that is, different from the cushions 4a, 5a, between the cover 2a and the shell 2. The purpose of the cushions 4a, 5a is to form padding between the generally rigid structure of the seat 1 (that is the shell 2) and the driver's body. These have both the function typical of padding (absorbing forces which can arise during movement) and that of holding the driver's body more precisely and effectively in the seat 1. Each cushion may in turn be constituted by a single air chamber (inflation chamber) with a respective inflation valve or by a plurality of air chambers, preferably independent from each other and each having a respective inflation valve. The provision of several independent air chambers has the advantage of enabling each air chamber to be inflated differently according to its spatial location in the seat (and thus its position relative to the driver's body) so as to achieve a specific volume and/or a specific inflation pressure, and hence a specific rigidity, according to the requirements in use. The solution of the invention thus starts from a generally standard seat structure 1 (shell 2 with cushions 4a, 5a) and - through selective inflation of the cushions - becomes a seat which, on its inner surface intended to receive the driver, has a conformation and characteristics of rigidity adapted, even locally (particularly when each cushion is constituted by several air chambers) to the specific anthropometric characteristics and/or tastes of the individual occupant. The inflation of each cushion to a greater or lesser extent (that is to a greater or lesser pressure) also enables the seat 1 to be adapted to different requirements of use, for example to accord with differing track characteristics, to provide a choice, for example, between a generally softer, less restraining seat (cushions inflated to a "low" pressure) and a harder seat which clamps the driver's body more firmly (cushions inflated to a "higher" pressure). The schematic drawing of Figure 2 shows how the invention lends itself to being embodied in a dynamic configuration in which the degree of inflation (pressure) of each cushion 4a, 5a may be varied selectively, even during driving, and thus even when the seat 1 is occupied by the driver, for example during a sports competition. The invention as shown in Figure 2 provides for the cushions 4a, 5a to be connected to a source 8 of pressurised fluid (typically pneumatic, although pressurised liquids may be used in certain cases - at least for some cushions or portions thereof) with the interposition of respective valves (solenoid valves) 9a, 10a (there are two of the latter since two cushions 5a are provided, one for each side 5 of the seat) controlled by a single processing or control unit 11. Figure 2 refers, for simplicity, to a solution in which each cushion 4a, 5a is individual in the sense that it comprises a single air chamber. It goes without saying that, if one or more of these cushions includes several air chambers, the solution of the invention may involve the provision of a corresponding number of solenoid valves. In general the cushions 4a, 5a are initially to a reference pressure and then, during travel, by operation of the solenoid valves 9a, 10a the inflation pressure may be varied at will, both to increase it (by opening the solenoid valves 9a, 10a to positions in which the respective cushions are put in communication with the pressure source 8) and to reduce it (the valves 9a, 10a being switched to the positions in which the respective cushions are put in communication with a vent line to the exterior). For this purpose the solenoid valves 9a, 10a are typically valves which each have three connectors or ways: to the pressure source 8, to the respective cushion and to vent, typically the atmosphere. All this allows the selection of three operative positions, that is to say: closed (with all three ways closed), the inflation pressure of the cushion being kept constant, connection of the pressure source 8 to the respective cushion 4a, 5a so as to increase the pressure to which the cushion is inflated, and vent of the pressure in the cushion to the exterior with a consequent reduction in the inflation pressure. Although this may be more complicated from an operational point of view it is possible to provide for the pressurised fluid resulting from the venting of one cushion not simply to be discharged to the exterior. It is in fact possible to connect the various solenoid valves together, at least temporarily, (connections indicated schematically in broken outline by the reference 100 in Figure 2) so that the pressure vented from one cushion is used at least partly to increase the pressure in another cushion. This is the case, for example, in solutions which provide for the control of the unit 11 by accelerometric signals (as best seen below), with the consequent possibility that the excess pressure resulting from the reduction in the inflation pressure of the cushion 5a on one side of the seat is used to increase the inflation pressure of the cushion 5a on the opposite side. With regard to the pressure source 8 it is possible to use various solutions, particularly when one is dealing with a pneumatic source. For example, the source 8 may simply be a cylinder: this solution has been shown to be advantageous particularly in those cases in which weight and bulk are determining factors. Alternatively the source 8 may be constituted by, or at least include, a compressor preferably with an associated pressure accumulator. This solution, at least in some applications, may be exacting in terms of weight and - particularly - in that it will drain a degree of power from the propulsion unit of the vehicle. The solution of the invention, however, lends itself to the use of a compressor which can be activated, for example, only during the deceleration of the vehicle. In this case, as well as not draining useful power from the propulsion unit, the compressor cooperates with the vehicle's braking system in effecting the deceleration. With regard to the control unit 11 which governs the activation of the solenoid valves 9a, 10a (and hence controls selectively the inflation pressure of the cushions 4a, 5a), this may be an electronic control unit (of a type known per se) arranged to operate automatically in dependance on signals from two accelerometric sensors 12a, 12b mounted on the vehicle and in general sensitive to: accelerations forward and rearward of the vehicle (sensor 12a); and accelerations transverse the vehicle (sensor 12b). One is dealing with known accelerometric sensors, known particularly from the aeronautical field in which they are currently known as G-meters. More particularly, the unit 11 may be programmed so that, during a strong forward/rearward acceleration of the vehicle (for example as a result of a sharp acceleration such as that which occurs during the starting phase of a competition or a resumption of driving) the signal produced by the sensor 12a - through the unit 11 and the valve 9a - causes an increase in the inflation pressure of the cushion 4a which is at the top of the backrest 4. Thus it is possible to avoid the driver's back being squashed against the shell of the seat 2 since the cushion 4a is interposed like elastic padding between the shell 2 itself and the driver's back. Once the strong acceleration has ceased, the inflation pressure of the cushion 4a may be returned to a normal reference value (selected by the driver) so as to achieve the appropriate padding for normal driving conditions. The same solution is adopted for the side cushions 5a. When the vehicle is moving in a straight line, these are kept at a uniform pressure (the cushions possibly being at different pressures if so desired by the driver) and the pressures are then increased selectively when the vehicle changes direction and the driver's body is thrust sideways - by centrifugal force - towards one side 5 of the seat 1. The sensor 12b detects the strength and direction of the centrifugal acceleration and acts through the solenoid valves 10a to increase the inflation pressure of the cushion which is compressed at that moment between the driver's body and the side 5 towards which the driver's body is thrust. More particularly, in the case of a zig-zag path, the inflation pressures of the cushions 5a on the two sides are modified alternately, with the possibility of using at least some of the excess pressure discharged from one cushion to increase the pressure in the cushion on the opposite side (line 100 in Figure 2). Obviously, the principle of the invention remaining the same, the constructional details and forms of embodiment may be varied with respect to those described and illustrated if not thereby departing from the scope of the present invention as defined in the appended claims.

Claims: A seat for a vehicle subject to forward/rearward accelerations and transverse accelerations, the seat including a receiving structure (2) which, as a whole, is rigid and has a surface adapted to receive at least part of a user's body and having selectively inflatable cushion means (4a, 5a) adapted to be interposed between the structure and the user's body in use, wherein: the structure includes two opposite sides (5) and a backrest (4) with a respective upper end, the inflatable cushion means include at least two inflatable cushions (5a) provided one against each of the sides (5), respectively, and/or at least one inflatable cushion (4a) provided at the upper end of the backrest, an associated pressurised-fluid source (8) is provided, for the inflation of the cushion means (4a, 5a), valve means (9a, 10a) are interposed between the cushion means (4a, 5a) and the pressurised-fluid source (8), the valve means (9a, 10a) having associated control means (11) to switch the valve means (9a, 10a) selectively between: a closed position, a first open position in which the valve means (9a, 10a) put the pressurised-fluid source (8) in communication with the cushion means (4a, 5a), and a second open position in which the valve means (9a, 10a) put the cushion means (4a, 5a) in communication with a vent outlet, the control means (11) have associated accelerometric sensor means (12a, 12b) whereby the inflation pressure of the cushion means (4a, 5a) is controlled in dependence on signals generated by the accelerometric sensor means (12a, 12b), wherein: the accelerometric sensor means include a forward/rearward accelerometer (12a) sensitive, in use, to the forward/rearward accelerations of the vehicle on which the seat is mounted and the control means (11) act to increase the inflation pressure of the cushion (4a) associated with the backrest of the seat (1) when the vehicle is accelerating, and/or the accelerometric sensor means include a transverse accelerometer (12b) sensitive, in use, to the transverse accelerations of the vehicle on which the seat is mounted and the control means (11) vary selectively the inflation pressure of one and the other of the cushions (5a) associated with the sides (5) of the seat (1) in dependence on the signal generated by the transverse accelerometer (12b) sensitive to transverse accelerations of the vehicle. A seat according to Claim 1, characterised in that said pressurised fluid is a gas. A seat according to any one of the preceding Claims, characterised in that the receiving structure has an associated covering layer (2a) and in that the cushion means (4a, 5a) is interposed between the structure (2) and the covering layer (2a). A seat according to Claim 3, characterised in that the covering layer (2a) has apertures (6) in correspondence with the cushion means (4a, 5a). A seat according to Claim 1, characterised in that the pressurised-fluid source (8) is a cylinder. A seat according to Claim 1, characterised in that the pressurised-fluid source (8) comprises a compressor. A seat according to Claim 6, characterised in that the compressor is driven by the propulsion unit of the vehicle and is activated selectively during deceleration of the vehicle itself. A seat according to Claim 1, characterised in that it includes at least one pair of inflatable cushions (4a, 5a) and in that, when one of the cushions (4a, 5a) is deflated, the respective vent outlet is connected (100), at least temporarily, to another cushion which is inflated.

Inventors: FERRERO PIETRO, FERRERO, PIETRO
Applicants: FERRERO SPA, FERRERO S.P.A.
Application year: 1995
Main classification: B60N2
IPC codes: B60N2