FR2532172A1 - Very comfortable wheelchair for seriously disabled person - Google Patents

Abstract

The invention relates to a wheelchair for a seriously disabled person. Its modular design allows four modules of a central box to be separated by the removal of four pegs. The wheels are coupled in pairs by means of flat springs providing very soft independent-wheel suspension. The footrest retracts when obstacles are encountered, moving back into position afterwards. The chair comprises an anti-sore device obtained by an oscillation of the seat under manual or automatic control. An accessory device enables the passenger to be transferred with the seat part of the chair to the seat of the standard vehicle in which there is no special equipment. The electronic control of the chair divides out cycles of equal duration. A decision taken within each cycle enables the actual movement of the chair to be brought into line with the passenger's commands. The invention may be adapted for special disabilities.

Description

 The present invention relates to a wheelchair for the handicapped major, specially designed to ensure a great comfort of the passenger and to require a less effort of the guides. I1 further comprises a device intended to prevent the formation of pressure sores.

 In existing armchairs, the seat is fixed on a more or less rigid structure which does not give a great flexibility of suspension, moreover, once the seat placed in the desired position, the passenger does not modify it. Loading and unloading the passenger in a car is always a delicate and painful operation requiring great physical effort for the attendant and a risk of lumbar accident. Some armchairs are specially-designed to solve this problem, but it is always necessary to have a specially equipped vehicle. Finally, disassembling the chair to load it in the car is always a fairly long operation.

 The present invention provides original solutions to these various points.

The armchair is made up (figure 1) by a central box in reinforced polyester 5, or any other light structure, on which are fixed in an instantaneous way, without effort and without tools the other elements: (see figures 1 and 2 Y - seat 1 - steering gear 2 (it can be front or rear) - power train 3 (it can be rear or front) - running board 4 - control 8 (in the case of manual control only)
In box 5 there are also - the batteries (which can be removed instantly) - the control electronics - the seat oscillation support
The great flexibility of suspension is obtained by fixing each group of wheels (driving or steering) at the two ends of two wide and thin leaf springs embedded in a central support fixed to the box (Figure 9). The installation on the one hand at the level of the wheels and on the other hand on the central support avoids the twisting of the bars which deform according to the bending forces, each wheel is therefore supported by a flexible curvilinear parallelogram giving a deflection vertical of the wheels, each of them being perfectly independent of the others
The set of two springs, associated wheels and the device
fixing on the central support forms a whole that can be instantly separated from the box by removing two keys 13 (figure 3). These keys are cams which plate small blades forming counter-springs - 12 and the spring blades 9 on the support 10 ensuring thus 11 recessing of the springs thanks to the lateral guides of the support 10
The steps of the wheelchairs are always adjustable, but fixed, which has the following drawback in particular: when the passenger is tall, the step is close to the ground (without this it would be necessary to extend the legs forward this which is annoying because it increases the size of the chair) and this often prevents the disabled from crossing a sidewalk boat because his footboard comes to rub on the ground (Figure 4) on the rise as on the descent, he is then forced to do call to a third party.

In the present invention, the step is adjustable and eclipsable (Figure ç): the footrest 4 is rotatable relative to the tube 15, it can be more or less raised by moving the rollers 17 and more or less elongated by sliding from 15 to 16
When these adjustments have been made definitively for the passenger of the wheelchair, if the running board encounters an obstacle, it disappears while rolling on the rollers 17 18 and 19 to occupy the position marked with dotted lines and resumes its position after having crossed the obstacle . The underside of the step is arranged to facilitate sliding over an obstacle (for example, Teflon coating). The same result can be obtained by mounting the step on an articulated parallelogram, for example.
In addition, the roller 19 presses on the heel 20 thanks to the action of a spring, this gives damping during small, fairly frequent frontal shocks.

Finally, the running board is instantly separated from the chair, during disassembly by rotation of the assembly as indicated by the floche F which releases the heel 20 from the roller 18. The reassembly is also instantaneous by engaging the heel 20 under the roller 19 and folding the assembly.

This footstep presented in the version where the two feet are of the same level can also be adapted to asymmetrical situations by adding wedges, gutters or specially adapted footrests.

 Farmi wheelchair users find themselves very paralyzed. One of their major problems is the training of escarrea at support points. Owing to their immobility and their lack of sensitivity, the points of support, where there is compression of the tissues, remain the same for long periods. One of the essential characteristics of this armchair is to have created an oscillating seat whose inclination changes by a significant value in different directions at regular time intervals (for example every ten minutes the inclination of the seat can vary from 100 in different directions), the support points are no longer the same and consequently the blood circulation can be restored normally in the areas which have just been decompressed.

 An example of the realization of the seat oscillation is as follows (Figure 6) '. The seat support is fixed at a central point 2 2 (silent-block, ball joint, etc.), two electric jacks 23 controlled either automatically or manually using a switch by the passenger position the seat tilt around 4 extreme positions: the two closed jacks lean the seat back, open straighten it, one open and the other closed lean the seat on one side, reversing the direction of the jacks it leans on the other side This oscillation of the seat may well be obtained by using other techniques ensuring the same result, that is to say a displacement of the passenger's support points.

 The chair object of this invention, comprisesun device allowing anyone to effortlessly load the passenger in a vehicle not specially fitted out. To do this, the seat is transferred by sliding (or rolling) on slides with removable properties to the car seat.

 An exemplary embodiment is as follows: The seat (see FIG. 1) has 2 tubes 6 which are integral with it, they rest in slides 7 (FIG. 6). In the wheelchair use position, the seat is immobilized in the slides by 4 pivoting clips 21. When we want to transfer the passenger from the wheelchair to a car, we place on the vehicle seat a perforated plate 27 (Figure 7), the holes 28 used to immobilize the plate because it fits into the vehicle seat when loaded This plate has immobilizer clips 21 for attaching the wheelchair seat to it when the transfer is complete. Sliding slides 29 (variable length from 0.60 to 1.00) are attached to it on one side, on the other they are attached to the legs 24 (FIG. 6) which extend the slide 7. I1 then suffices to slide the seat of the chair loaded with its passenger after having opened the fixing clips 21 and folded the operating handles of the chair, up to the plate 27 above which it is fixed by the clips.

 If the vehicle is a station wagon, the rest of the wheelchair can get on it using small ramps on its own. If the r.e vehicle does not allow this maneuver, the chair is separated into 4 sets by removal of 4 keys and the 4 constituent elements are loaded: front axle, rear axle, step, box.

On arrival the maneuver is the same in reverse. This same device can be used, if need be, to transfer the passenger to a bed;
The chair is controlled electronically and implements an original program made possible by the use of a microprocessor.

As is often the case in automation, control is obtained by comparing two voltages: on the one hand that supplied by the passenger depending on the movement of a lever acting on a couple of potentiometers (one for each of the wheels drive), on the other hand that provided by each of the motors according to its real speed, one can, to obtain it, use a small annex generator, a tach4'mètra, a generator d 'impulses or use any other system giving an image of the speed of the motor, for example its counter-electromotive force.

 As a function of this comparison, the evolution of the average voltage sent to the motor is generally fixed by using a chopper system which produces a periodic current of fixed frequency and varies, within each period T, the duration for which voltage is applied, the average voltage varies as U = 8 (Figure 8).

In the armchair, object of this invention, the use of the microprocessor makes it possible to easily carry out the following original program
At equal time intervals sufficiently close to obtain satisfactory mechanical continuity by mechanical inertia, the microprocessor examines the state of the following elements successively for each of the power units - parking brake: applied or removed - voltage sent to the motor: O or 24 volts (if 24v is the supply voltage
indication) - direction of current flowing in the motor: front (+) or rear (-) - motor brake (rotor short-circuited): set or removed
Based on the information thus collected and the result of the comparison between the actual speed and the requested speed, the microprocessor makes the necessary decision; after a fixed waiting time (which defines the pseudo operating frequency) the microprocessor starts a new cycle of interrogations and decision-making, the corresponding flowchart is shown diagrammatically in FIG. 9
Each cycle, the microprocessor modifies only one element, here is an example of control which will make understand the servo-control (figure 10) the wheelchair is stopped, the passenger advances his joystick to a position corresponding, for example, to 1 km / H, - in a first cycle, the microprocessor will notice that the im
mobilization is tight, it will give the order to loosen it, - in the 2nd cycle, after having observed that the immobilization brake
is not switched on and the wheelchair speed is lower than the speed
requested, if the motor is plugged in the right way, it will send the
current under 24 volts in the motor, - in the following cycles, it will not change anything until the speed
reaches 1 km / H, - then the current will be cut, then restarted to maintain this speed,
possibly downhill he can put and remove the engine brake
or even, if the slowdown is not enough, change the direction of bran
the engine and send pulses in the opposite direction to maintain
set speed to 1 Km / H
All this will be done with sufficiently short cycles so that, taking into account the mechanical inertia, the operation is continuous.

This original operating program makes it possible to adapt the operation to the handicap of the passenger, we give below 3 examples, it being understood that other cases can be solved in a similar way.
1). A perfectly mature passenger on the order can benefit from the program which has just been described without modification, this will give him a wheelchair that reacts directly and quickly to reach the requested speeds.

2). For certain cerebral palsy who do not have motion stability and who move the control lever around the desired position in a disordered manner, the microprocessor program is modified to take into account not the value of the command given by the passenger at time t but the arithmetic mean of the values given between times t 'and t separated by a constant interval dt, dt being a function of the handicap
30). In the direct control of the first example, the progressiveness is controlled by the passenger himself who advances the control lever more or less quickly. Some will prefer to have a more flexible and less direct control, in this case the microprocessor program is modified by spreading the variations of the control voltage over a greater or lesser number of cycles according to the desired progressiveness.

Claims (6)

 1. The present invention relates to an autonomous wheelchair for the handicapped major, specially studied for the comfort of the passenger, avoiding the formation of bedsores and reducing the efforts of the accompanying persons. The suspension, very flexible, with independent wheels, is characterized by the use of wide and flat springs associated by two forming curvilinear deformable parallelograms coupling two wheels and embedded in a central support.  Armchair according to claim 1 comprising an anti-square device characterized by an oscillating suspension of the seat, this oscillation can be provided by electric jacks, it is controlled directly by the passenger or automatically according to an electronic device, for example.  Armchair according to claim 1 comprising a charac footrest  erected by the fact that it is eclipsable and rises automatically when it meets its obstacle, that er. circulating the support of the footrest in slides or on rollers or by fixing it on articulated rods.  4. Chair according to claim 1 comprising an annex device making it possible to pass the passenger with the seat part of the chair, without effort, from the wheelchair to the seat of a standard and reverse car, characterized in that it includes an additional support placed on the car seat, drilled to ensure its stability, comprising fixing clips to immobilize the seat and anchor points to receive extendable rails linking it to the base of the wheelchair , on which the movement takes place.  5. Armchair according to claim 1 characterized by its modular design in 4 elements instantly separable from a central box, in reinforced polyester for example, in which the batteries and the control electronics are placed; the connection being obtained by 4 keys forming cams.  6. Chair according to claim t comprising an electronic control characterized by a program controlling the chair to the desires of the passenger by testing at very close equal time intervals the different walking factors and modifying inside each inter- it n bes elements to approach the requested operation.  7. Chair according to claims 1 and 6 comprising an electronic control characterized in that it can be adapted to - - @ és @@@ have no movement stability taking into account, not their request at time T but the mean of their dem @@ d @ at the  tt of a time interval dT preceding the instant T, dT being a function of their handicap.  8. Chair according to claims 1, 6 and 7 comprising a control  characterized by the fact that it can be adapted to steps  sagers requesting progressive order by distributing the variation of  command at time T on a number N the cycles, N being a function of the  desired progressiveness.