FR2495451A1 - Motor vehicle seat for persons with reduced mobility - uses hydraulically actuated seat which turns and assists occupant to stand, under electric control fitted to walking stick handle - Google Patents

Abstract

The seat uses hydraulic actuators with their valves electrically controlled to move the seat backwards, rotate it so that the occupant is facing the door, and lower it so the occupant's feet touch the ground. An arm (3) then lifts the person from the seat by pushing under the thighs and provides a support till the person is standing. The controls (20) are fitted to the handle of a walking stick (23) and plugged into a flying lead (21) from the motor vehicle. These operations are performed by hydraulic cylinders attached below the seat (5) and in the seat back (2). The cylinders have solenoid valves in their hydraulic supply line, and the solenoid valves are activated by electric signals from the control panel fitted to the walking stick used by the handicapped person.

Description

Seat for people with reduced mobility, in particular for disabled drivers of motor vehicles.

 The present invention relates to seats for people with reduced mobility, such as the disabled with myopathy, more particularly, but not limited to, for motor vehicles, these seats being of the type comprising a seat and a backrest mounted on a support intended to be fixed on a floor.

 There are already known, for example from French patent application No. 80 11 803, seats of this type which are more particularly intended for severely disabled persons, such as quadriplegics, and which have to be transported as passengers in a motor vehicle, such a seat allowing the transfer of the handicapped person from his rolling cart to the passenger seat of the vehicle and vice versa. To this end, this seat is firstly mounted mobile on its support, which in this case is integral with the vehicle floor, in three different movements allowing it to be brought outside the vehicle, while it is by elsewhere mounted removably relative to this same support so as to simultaneously allow its separation with respect to the latter and its attachment to the trolley. The three movements considered are respectively a tilting of the entire seat with respect to the rear to a base mounted on an intermediate chassis, so as to raise the passenger's feet above the level of the arch of the door arch, a rotation of said intermediate chassis around a vertical axis disposed near the middle foot of the vehicle, so as to bring the seat outside the vehicle, and finally, after reverse tilting, a translation of the base relative to the intermediate chassis to bring the seat in cantilever and allow its mounting on the trolley rolled .

 The commands for these various operations which allow the seat to be entered or removed are purely manual and are carried out by a third person who assists the patient and who is absolutely necessary because of the impossibility in which the patient finds himself. do it himself. This third person can, of course, be the driver of the vehicle itself since such a seat is only provided for passengers, the handicaps with which the latter are affected preventing them from driving the vehicle themselves. In addition, this exclusive application for passenger seats makes it possible, for the various movements, to have a space free from obstacles such as steering wheel and dashboard, which simplifies the kinematics to be provided for exiting or entering the seat. .

 Unlike these seats which are exclusively intended for people with practically zero mobility, such as quadriplegics, the present invention aims to provide a seat which can be used by people with reduced mobility only, such as the handicapped with myopathy, c that is to say a weakening or atrophy of certain muscles, while the paralysis results in a very pronounced abolition of motor skills. Myopathic states allow. effect in general to the patient to remain in a standing position using crutches or canes, and also to move using these same aids. Their muscles are however too weak to allow them to get up until the vertical position from a seated position and it is mainly for this purpose that the seat in question should be designed.

 To this end, the subject of the invention is a seat of the "aforementioned type, characterized in that at least part of the seat, located at the front thereof, is mounted movable vertically relative to the rest of the seat, under the action of motor means actuated by a manual control member, while the back of the latter is, on the other hand, mounted stationary in the vertical direction.

 Thanks to this arrangement, it is enough for the user of the seat, when seated, to maneuver the manual control member so that the driving means cause the lifting of the movable part of the seat, which is located under the thighs of the user, so that it is gradually straightened to a position close to the standing position.

 In a particular embodiment of the invention, it may also be provided with support means located on the side and above the movable front part of the seat cushion, in its high position, which allows to the user to grasp these support means with the help of at least one hand and therefore to be able to balance his body well while it is lifted by the seat. support can be constituted by a cane (or a crutch) and the manual control member can be arranged on the handle of this cane (or the crosspiece of the crutch), which allows the user to have already, simultaneously with its lifting, of the instrument which must then allow it to move.

 The drive means provided for lifting the movable part of the seat are preferably constituted by a hydraulic or pneumatic or electric actuator, disposed between this movable part of the seat and the fixed part of the seat and connects to a source of compressed fluid, as well as the manual control member. Such a jack ensures perfect regularity and smoothness of the lifting movement, as well as very precise positioning and stopping of the mobile part of the seat in the optimal position desired by the user, but above all, and this is the essential advantage of the means here provided, obtaining an assisted movement, the user therefore being able to be alone to carry out the maneuver, and lockable in any position, which ensures perfect safety of the device, fundamental for a disabled person.

A seat thus equipped can find many uses, various, but all equally advantageous for the disabled person who uses it, whether for example as a seat of a motor vehicle, allowing the recovery of the person who occupies this seat, once it has been brought outside the passenger compartment of the vehicle using additional means, or even as a work or leisure seat associated with a table or a work station, in which case it is appropriate also to remove this seat from this table or this post using similar complementary means, or as a simple meal or leisure seat in an apartment or hospital room, without any other associated element which should be agreed upon. dismiss, in which case the means previously provided are sufficient in themselves
In a particularly advantageous manner, in the first two preceding cases, it is possible to provide, as complementary means, either means for mounting the seat in rotation relative to the fixed support, or means for mounting in translation of this seat relative to this support, these mounting means being associated with motor means actuated by the same manual control member as previously. This allows, in both cases, to move the seat so as to move it away from either the dashboard in the case of a passenger car seat, and especially the steering wheel in the case of a driver seat, either still from the table or the work station in the second application envisaged, which allows in both cases a release of the knees and the part lower body compared to the obstacle considered. In the case of a vehicle seat, once the knees are freed from any obstacle located above the gods thanks to a translation of the type proposed, a first raising allows the feet of the user to be raised above the bottom of the step to allow the seat to exit easily from the passenger compartment, while, after this exit, a second raising makes it possible to raise the seat and, consequently, the entire body of the user to bring him to a standing position. In the case of a seat for a table or work station, once the knees have been freed by a rotation or a translation of the type considered, a lifting corresponding to the aforementioned second lifting allows the user to stand directly upright.

 In a particularly advantageous embodiment of the invention, namely that of a seat for a motor vehicle, it is advantageously possible to combine the two movements of rearward translation and of rotation, the axis of rotation being arranged not only at the rear of the seat, but also on the side thereof, on the door side, while there is also provided an intermediate support between the fixed support and the base of the seat, means for mounting in rotation being arranged filter the intermediate support and one of these two other elements, and means for mounting in translation between the same intermediate support and the other of these elements.

This double movement allows the seat to come out of the passenger compartment, first of all by a recoil which frees the knees compared to the dashboard (and especially compared to the steering wheel in the case of a driver's seat), allowing thus raising the feet above the level of the bottom of the step, using the movable part of the seat, then by a rotation which brings the seat outside, then allowing the feet to rest on the ground at using the movable part of the seat and finally lifting the thighs and the whole body using this same movable part, with possibly, in the meantime, a possible movement of translation bringing out the seat even more of the passenger compartment.

 In the most particular embodiment envisaged for the invention, namely that of a driver's seat, the translation mounting means can be slightly inclined relative to the front-rear direction of the seat, so that the rear part of these means approaches the axis of rotation, which makes it possible to separate the seat from the central console and place it in the optimal position allowing the various movements provided with the minimum of discomfort.

Other characteristics and advantages of the invention will emerge from the description which follows, by way of nonlimiting example, and with reference to the appended drawings in which:
- Fig. 1 shows a perspective and schematic view of a seat according to the invention, intended to constitute a driver's seat for a motor vehicle;
- Fig. 2 shows a front view and partially in section, of the seat according to the invention, including its fixed support allowing the attachment to the vehicle floor;
- Fi.g. 3 shows a top view of this seat, the padding of the cushions being assumed to have been removed, as in FIG. 2;
- Figs. 4, 5 and 6 illustrate with the
Fig. 3, the different horizontal movements allowed for this seat, these three figures being on a smaller scale;
- Fig. 7 shows a side view of the seat of FIGS. 2 and 3, further illustrating the lifting movement according to the invention;
- Fig. 8 schematically represents the electro-hydraulic control assembly of the seat;
- Figs. 9a to 9h illustrate the use of this seat;
- Fig. 10 shows in perspective the seat in the final position of use.

 The seat shown diagrammatically in FIG. 1 comprises first of all the seat proper, which is made on a frame, not visible in FIG. 1, but which will appear more clearly in FIGS. 2 and following, this frame carrying a seat 1 and a backrest 2 which are mounted in the normal position allowing the sitting position of a person, and which are fixed or adjustable relative to each other in this position, l 'set being completed by a movable part of the seat, part 3 which is located at the front of the seat itself 1, and which is hinged on the backrest 2 using lifting arms 4.This movable part is shown in normal position extending the seat itself 1 forward, shown in phantom, while it is shown in raised position in solid lines.

 The seat frame itself 1-2 is mounted, as will be described in more detail below, on a base plate 5 which is mounted in translation, by means of translation means 6, on an intermediate support constituted by a plate or plate 7, this plate 7 itself being mounted mobile in rotation, by means of rotation 8, on a fixed support constituted by a plate or plate 9, which is fixed permanently on the floor 10 of the vehicle. To allow the translation means 6 to be seen, the seat has been assumed to be offset vertically relative to the plate 7, along the lines in phantom.

 As shown now, more specifically, Figs. 2, 3 and 7, the frame of the fixed part 1 of the seat is constituted by a U-shaped frame 5a, arranged around the aforementioned base plate 5, and fixed thereon for example by studs. This plate 5, substantially square, has at its rear part, and on its dimensions, two horizontal extensions 5b arranged at the rear of the pairs of side members 3c of the mobile part 3a.

 The backrest frame 2 is also constituted by a frame comprising, joined by various crosspieces, two uprights 2a which are fixed on the base plate 5 inside, and slightly behind the rear part of the side members 3c, by the intermediate reinforcement angles 2b.

 The frame of the movable part 3 of the seat is constituted by a cross-plate 3a which is partially inclined forward and downward, which, in the normal position, shown in solid lines in FIG. 7 ", is placed at and at the front of the frame 5a of the fixed part of the seat and which is attached to a U-shaped frame comprising a front cross member 3b and two pairs of side members 3c disposed on each side, and provided with 3d connecting spacers The two articulation arms 4, shown diagrammatically in Fig. 1, are bent arms each comprising a spar 4a which is fixed on the outer side of the corresponding outer spar 3c and which, in normal position, is arranged horizontally at the level of the plate 5 and of the frame Sa, this spar extending at its rear end by an upright 4b inclined upwards and backwards, and articulated around a transverse horizontal axis 4c on the associated backrest upright 2a, this upright 4b also being counter-bent so as to come into contact with this upright In order to stiffen the whole of the arm, there is also provided an oblique tie rod 4d joining its spar 4a and its upright 4b.

 As shown in Figs. 1 and 3, the fixed support or plate 9, which is fixed to the floor 10 of the vehicle, has the very approximate shape of an L, a branch of which is disposed along the sill 11 of the vehicle door associated with this seat, the angle of this plate being disposed near the upright or rear leg 12 of this door, the second branch of the plate being oriented transversely relative to the sill. On the angle of this plate 9, there is permanently fixed a pivot 13 with a vertical axis carrying two ball bearings 13a, and itself held at its base by radial vertical reinforcements 13b, fixed on the plate 9.

This pivot is located substantially at the height of the rear door leg 12.

 The intermediate support or plate 7 is disposed above the upper level of this pivot, and cantilevered relative to the latter, on the side of the interior of the vehicle, this plate being integral with one of its corners d 'a sheath 7a which is fixed under its surface and which internally receives the two ball bearings 13a, thus allowing rotation of the plate 7 about the vertical axis XX of the pivot 13.From its corner mounted on the pivot 13 , the plate 7 flares along a first part 7a under which is fixed an articulation block 7b of the free end of the rod 14a of a jack 14 whose body is disposed horizontally between the two plates 7 and 9, so as to be oriented parallel to the step 11 in the normal position shown in FIG. 3, the body 14 of this jack being mounted at its other end on a fixing block 9a secured to the plate 9 at the front end of its longitudinal branch. This jack is practically visible only in FIG. 2, since in the top view of FIG. 3, it is located exactly below another cylinder which will be described later, only its rod 14a and the fixing block 7b of the latter appearing in broken lines in this Figure.

Beyond its flared part 7a, the plate 7 is extended by a second part 7c of trapezoidal shape and the end edge of which is slightly inclined, for example from about 15 to 20, relative to the longitudinal axis of the vehicle or of the seat YY (parallel to the direction of the bottom of step 11), this edge being inclined towards the rear and towards the outside of the vehicle, that is to say on the side of the door leg 12. Between the sheath 7a and this extreme edge, the plate 7 also comprises, on its lower face, vertical reinforcements 7d. On its upper surface, the plate 7 receives, fixed on it, two parallel slides 6a (forming part of the means of translation of the Fig. 1), arranged, one along the extreme edge of the plate 7, and the other towards the inside thereof. With these slides, which are of the ball slide type, cooperate, with the interposition of two sets of balls 6b, two pads 6c which are permanently fixed under the base plate 5 of the seat.
The two slides 6a are oriented in the inclined direction ZZ of the extreme edge of the plate 7 (in the normal position of Fig. 3), and their front ends slightly overhang the front edge of this plate 7, so that the area in overhang of the outer slide (that is to say has the side of the step 11) is placed, in the normal position shown, very approximately in the middle of the base plate 5 of the seat, while the the end of the other slide is located more towards the interior of the vehicle.

 Under the plate 7, and in-an intermediate location between the two slides 6a which are located on the upper face, is fixed the body 15 of a jack, oriented parallel to the same inclined direction ZZ as the slides, and whose rod 15a protrudes from the front of the plate 7 so as to be fixed at its free end to a fixing block 5c fixed permanently under a tab 5d which protrudes from the front and from the side of the internal angle of the plate 5.

 As shown in Fig. 3, in the normal position of the seat, the front edge of the plate 7 as well as the front end of the cylinder body 15 are located very slightly behind the middle of the plate 5, while the tab 5d and the block fixing 5c are located in front of this plate, the rod 15a of the jack then being in the maximum extension position. (It is also the same for the cylinder 14 are the rod 14a is, in the normal position shown in Fig. 3, in the position of maximum extension).

 In this normal position shown in FIG. 3, the base plate 5, and therefore the entire seat, are in a maximum forward position (since the rod 15a of the jack 15 is in full extension), this position corresponding to a driving position in which the movable part 3 of the seat, and therefore the driver's knees, are normally located below the steering column and the steering wheel.

From this position, the actuation of the actuator 15 using means which will be described later, causes its rod 15a to retract and consequently a retreat of the base plate 5 and of the entire seat backwards and slightly to the side, towards the door leg 12, as shown in Fig. 4. The stroke of the jack 15 is such that, in this position of maximum recoil, the center of the plate 5 and consequently of the seat, have come practically at the height of the pivot 13 and of the door leg 12, or possibly very slightly in before this position. Simultaneously the plate 5 and the seat are slightly closer to the pivot 13 due to the inclination of the slides 6a.

This same Fig. 4 shows an additional profile 16 fixed on the floor 10, at the end of the fixed plate 9.

Once the seat is placed in this recoil position, the actuation, lt of the jack 14, using the same control means described below, causes the rod 14a to retract from the latter, thus causing rotation of the 'assembly of the plate 7 under which is fixed this jack rod, as well as the plate 5 and the seat, this rotation taking place around the axis XX of the pivot 13 and the stroke of the jack being such that, in the complete retraction position shown in FIG. 5, the assembly has pivoted by approximately 90, so that the plate 7, the plate 5 and the seat are partially extended by the opening of the door, being oriented with the axis
YY of the seat now arranged transversely to the vehicle.

In this position, a significant part of the seat, in particular its backrest, is still located inside the vehicle, the middle of the plate 5 being located approximately above the step 11.

 From this intermediate position5, a new actuation of the jack 15, but in the opposite direction and until maximum extension of the visa rod, causes the plate 5 and the seat to move forward relative to the intermediate plate 7, so that the seat is now located, as shown in Fig. 6, largely outside the vehicle, the rear edge of the plate 5 coming into this position approximately at the height of the pivot 13.

Simultaneously with this exit movement, the plate 5 has moved slightly, to the side, that is to say towards the front of the vehicle, due to the inclination of the slides 6a, so that the rear corner the outside of the seat is now placed very slightly in front of the rear door leg 12a. (To authorize the recovery operation which will be described later).

 Returning now to the normal position of the seat, shown in FIG. 3, as well as the corresponding side view represented by FIG. 7, the seat is completed by a third jack 16 which is arranged horizontally above the pair of side members 3c situated on the side of the pivot 13, the body of this jack 16 being fixed at its front end on a fixing block 16a fixed between the longitudinal members considered, while the jack rod 16b is fixed at its free end to a fixing block 16c secured to the extension 5a of the plate 5 located on the same side. In the normal position, in which the movable part 3 of the 'seat is arranged at the same level as the rest of the seat, that is to say with its frame 3a in the same plane as the plate 5, the rod 16b of the jack is fully retracted. As shown in phantom, the actuation of this jack 16, bringing the rod 16b into the position of maximum extension causes the movable part 3 to tilt upwards, around the axes 4c integral with the backrest, according to a angle which can reach 450.

 The actuator control assembly 14, 15 and 16, shown in FIG. 8, comprises, on the one hand, a power unit 17 and a connection box 18 which are connected together by a cable 19 and are both housed in the trunk of the vehicle and, on the other hand, a control unit 20 which is connected to the connection box 18 by a cable 21 and which is arranged near the driver, inside the passenger compartment of the vehicle. As shown more particularly in FIG. 10, this box 20, which is of reduced size, can be fixed on the side and inside the handle 22 of a rod 23 using a fixing ring 24.

 The power unit 17 essentially comprises a motor-pump group consisting of a motor 25 on the shaft of which a pump 26 is wedged and by a block 27 consisting of three hydraulic solenoid valves with drawers 27a. The hydraulic circuit of the pump 26 is completed by an oil reservoir 28 comprising a filling 28a, this reservoir being connected to the supply of the pump, while the discharge of the latter is connected, by means of d a non-return valve, on the one hand, to a supply pipe 26a for the three solenoid valves and, on the other hand, by means of a pipe 26b, comprising a flow adjustment valve, to a return pipe 26c which connects the outputs of the solenoid valves to the oil tank, with the interposition of a filter 26b.

The same solenoid valves 27a have pairs of control pipes 29a-3Qa, 29h-30b and 29c-30c which are connected respectively to the two ends of each of the jacks 14, 15 and 16. The electrical control circuits of each of the electro -distributors 27a, 27b, 27c are also connected respectively to the three groups of three conductors which constitute the connection cable 19 of the connection box.

 The electric motor 25 is, by tailors, supplied by two conductors, one of which is connected to ground, and the other is connected to a relay 25a from which two conductors 25b and 25c leave, the first of these being connected to the + terminal of the vehicle battery 31.

 The connection box 18 essentially comprises a diode plate 18a and four fuses 18b, three of which are connected by their input to an output conductor 18c of the box which is put in the bundle (pole -), while the input of the fourth is connected to the diode plate 18a. The input cable 21 comprises ten conductors including six conductors 21a which are connected, on the one hand, to six diodes 18d fixed on the plague 18a and. on the other hand, to six other conductors 19a which form part of the output cabal 19. The outputs of the three fusible branches 18b are. connected to three other conductors 19b to the cable 19. while the crimp of the fourth fuse 18b is connected to the conductor 25c of the relay 25a.

 'e control box 20 includes on its outer surface three rocker buttons 20a and a switch lock 20b. The rocker buttons 20e are three-position switch-buttons of which only the central position is stable and which correspond respectively to the control movement of the jack cylinders 14, 16 and 16, the extreme non-stable positions of these buttons corresponding respectively to the rear, left-right, ascent-descent. The lock 20b has two respective positions: on-off.The box also includes a terminal t 20c and a terminal - 20d, between which are interposed, via a conductor 20e, the lock 20b and an indicator 20f d 'walking indication. The three rocker buttons 20a is also connected by conductors 20g to the terminal + 20c, and the latter is itself connected to two of the conductors 21b of the cable 21, in the third case 21c of cable cases being connected to the terminal - 20d. As for the six conductors 21 for controlling the electro-distributors, they feel connected to the corresponding control rods for the three rocker buttons 20a.

 It can thus be seen that the use of this control assembly completes the forcing which has already been described for the three jacks 14, 15 and 16, with regard to FIGS. 3 to 7. In fact, the mete-pempe group 25-26 supplies in oil, the solenoid valves and these respectively actuate the different jacks 14, 15 and 16, according to the control pulses sent via the connection box 18 and the connection cables 19 and 20, from the three toggle buttons 20a.

 As shown in FIG. 105 the control unit 20 being mounted on the rod 23, when the driver wants to get out of the vehicle, it is very clear that the rod is arranged inside the vehicle, along the seat, so that the driver can enter the housing and press the desired buttons 20a. It is only as and when the various movements allowing the exit, that the driver gradually brings the rod outwards by holding its handle and the control unit 20 in the hand, until bringing it in the final position 23, shown in this FIG. 10.

As more precisely the
Fig. 9a to 99, the driver is initially in the normal driving position, shown in FIG. 9a, position in which the seat is in the position illustrated in FIG. 3, with the jack 15 in the maximum extension position and the seat brought back to the maximum under the steering column and the steering wheel 32. The driver then grabs the control box 20 and actuates the front control button 20a so as to cause the retraction of the jack 15, and consequently a complete recoil movement of the seat, even in the position of FIG. 9b which corresponds to the position of the mechanism illustrated in the
Fig. 4.In this same position of FIG. 9b, the driver actuates the up-down button 20a so as to cause an extension of the jack 16, this extension being however limited and not reaching the maximum position shown in FIG. 7, the partial lifting commanded by the button should be sufficient to raise the driver's knees in the position of FIG. 9b, for which the feet are situated slightly above the level of the step 11. In this position, the driver actuates the third button 20a left-right which causes retraction of the jack 14 and a pivoting of the seat towards the outside until adopting the position of FIG. 9c in which the seat has come to overlap the bottom of the step 11a, the driver now being turned towards the outside of the vehicle. The driver then actuates the up-down button so as to bring the movable part 3 back to the low position so that its feet now rest on the ground as shown in Fig. 9d.

 Figs. 9a to 9d were side views of the vehicle, while the following views 9e to 9h are rear views so that seat 1-2 is now seen from the side. From the position of FIG. 9d, the driver actuates the front-rear button so as to cause an extension of the jack 15 and, consequently, a total exit of the seat towards the outside, the backrest 2 of the latter practically being placed in the frame of the door, as shown in Fig. 9e.The driver then gradually activates the up-down button so as to cause a slow extension of the jack 16 causing the mobile part 3a to rise, the driver accompanying this movement so that part 3 is progressively placed higher and higher its thighs, so that this movable part 3, controlled by the actuator 16, completely controls the raising of the thighs of the driver until it brings it to the position that is fully upright in FIG. 9h in which the moving part 3 has slid down to the level of the gluteal muscles.

 In conclusion, it can thus be seen that, from the extremely simple handling of a control box held in the hand, the driver alone can, when he is suffering from a significant reduction in his mobility, find himself brought from @ the initial sitting position to the final standing position from which he can normally move using canes or crutches. Conversely, this design also allows the driver to be able to switch from the standing position to the sitting position without difficulty, and without having to resort to the help of a third person.

Claims (8)

 10) - Seat for a person with reduced mobility, of the type comprising a seat (1) and a backrest (2) mounted on a support (9) intended to be fixed on a floor (10), characterized in that at least one part (3) of the seat (1), located at the front thereof, is mounted movable vertically relative to the rest of the seat, under the action of the motor means (16) actuated by a manual control member (20), while the backrest (2) thereof is on the other hand mounted stationary in the vertical direction.  2 ") - Seat according to claim 1, characterized in that there is further provided support means (23) located on the side and above the movable front part (3) of the seat (1 ) of the seat, in its high position.  3) - Seat according to claim 2, characterized in that said support means (23) are constituted by a rod and the manual control member (20) is arranged on the handle (22) of this rod.  40) - Seat according to any one of claims 1 to 3, characterized in that it is provided with means (6) for spacing the seat relative to its position of use, the base (5) of the seat being movable ascent between this position of use and a withdrawal position in which the front movable part (3) of the seat (1) is released from any obstacle by comparison with its situation in the position of use, said means for spacing (6) being associated with motor means (15) actuated by said manual control member (20).  50) - Seat according to claim 4, characterized in that the base (5) of the seat is mounted movable in translation relative to the fixed support (9) between a position of use and a position of withdrawal, in a direction (ZZ ) oriented from front to back of the seat.  60) - Seat according to any one of claims 4 and 5, characterized in that the base (5) of the seat is mounted movable in rotation relative to the fixed support (9) between a position of use and a position of withdrawal , around an axis (XX) located at the rear of the seat, under the action of motor means (14) actuated by said manual control member (20).  70) - Seat according to claim 6 lersqu'elle depends on claim 5, characterized in that3 in the case where the fixed support (9) is fixed on a vehicle floor (10), the axis of rotation (XX) is arranged on the side of the seat. this side, while there is elsewhere provided an intermediate support (7) between the fixed support (9) and the base (5) of the seat, rotational mounting means (13) being arranged between the intermediate support (7 ) and one (9) of these two other elements (9,5), and means for mounting in translation (6) between the same intermediate support (7) and the other (5) of these elements (9, 5).  8) - - Seat according to claim 7, characterized in that the intermediate support (7) is mounted movable in rotation relative to the fixed support (9), and the base (5) of the seat mounted in translation on this support intermediate (7).  9) - Seat according to any one of Claims 5, 7 and, characterized in that the translation mounting means (6) are slightly inclined by bringing the front rear direction of the seat, so that the rear part of these means approaches of the axis of rotation (XX).  100) - Seat according to any one of claims 1 to 9, characterized in that the motor means (16, 15, 14) are constituted by a hydraulic cylinder connected to a source of pressurized fluid (26), as well as said manual control member (20).  11) -Seat according to any one of claims 3 to 10. characterized in that said manual control member (20) comprises at least one electrical switch (21a) interposed on the electrical control circuit of the motor means (16 , 15, 14).  12) - Seat according to any one of claims 1 to 11, characterized in that said manual control member (20) is disposed in a removable housing held in the hand or fixed to an auxiliary device for walking such as a cane (23).