FR2825615A1 - Four wheel drive wheelchair has internal combustion engine driving hydraulic pump to actuate wheel drive hydraulic motors - Google Patents

Abstract

The four wheel drive wheelchair (1) has a chassis (2) with a seat (3) and motors (6,11,12,13,15) to move the chair to the front and rear. The motors include an internal combustion engine (6) operating a hydraulic pump (11,12) for a circuit (13,15) to drive the wheels (24). The motors can be controlled by a lever (7) to control flow to the wheel motors.

Description

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MOTORIZED FOUR WHEELCHAIR
The present invention relates to a vehicle for the physically disabled, of the wheelchair type, for mixed indoor / outdoor use.

 In the current state of the art and know-how of manufacturing vehicles for the disabled, there are several types of more or less specialized vehicles.

 Thus, of course, the conventional wheelchair is known, comprising a tubular chassis in the form of a seat, mounted on an axle receiving two large wheels actuated manually by the user, and furthermore comprising two small self-steering wheels. This chair has the advantage of being light enough (generally between 10 and 15 kg) to be able to be handled by a single person. In addition, it is reduced in size, well suited for indoor use. On the other hand, not being motorized, it is of a painful use outside, especially on uneven or sloping ground. Thus, users of this type of wheelchair who wish to go for a walk must be content with a limited range of action, or else must obtain a second wheelchair more suited to an external environment.

 Precisely, the desire for increased mobility of the physically disabled outside allowed the development of several types of vehicles more suited to this kind of use. Thus, vehicles such as those marketed under the brand Buggy 2000 by Adam's Systems are known, or those marketed under the brand Optimus.

It is actually rather a small electric car, composed of a chassis carrying a seat, and comprising an electric motor and power batteries, as well as various accessories and safety devices, such as brakes, shock absorbers , lighting etc ...

 Although this vehicle can theoretically be used indoors and outdoors, it can hardly be

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 taken on a trip due to its high weight (more than 250 kg). In addition, these vehicles have only two driving wheels and are not suitable for all-terrain use. Finally, their autonomy is limited, and the battery charging time is several hours.

 For those users who still want to increase their mobility outdoors, even in natural surroundings, there are motor vehicles whose cockpit is designed to accommodate a conventional manual wheelchair. Such a vehicle is marketed by Aquitaine Concept Tout Terrain, under the Modul'Pro 4x4 brand. These are real 4-wheel drive vehicles, with a heat engine, an automatic transmission, and a weight of the order of 350 kilograms, so that they are not in themselves suitable for mixed use. , but the use becomes mixed interior / exterior only by juxtaposition of two vehicles, and therefore, the overall cost is much higher than the previous solutions.

 The state of the art which has just been presented shows that existing vehicles for the physically handicapped present a certain number of drawbacks if the aim sought is a truly mixed indoor / outdoor use.

In fact, to summarize: - there is no wheelchair which is intended and usable as well in indoor, outdoor and all terrain environment; - There is an all-terrain type chair, but it is operated manually;
The most efficient vehicles, including in off-road environments, are very heavy (several hundred kilograms) and do not allow indoor use; - There are certain electric wheelchairs, but they have only two driving wheels and have a reduced autonomy to the capacity of their batteries, and are unusable during the charging time of these, which is typically long.

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 The present invention aims to remedy the drawbacks of known wheelchairs, in the context of mixed indoor / outdoor use. More specifically, an object of the invention is to provide a wheelchair of dimensions similar to well-known manual wheelchairs, but nevertheless motorized and equipped for efficient use outdoors, even in natural terrain, without its weight or autonomy being disadvantageous. Another object of the present invention is to provide a wheelchair with great simplicity, a small number of components, and therefore a relatively low cost.

 To this end, the invention relates to a motorized wheelchair, comprising a chassis, a seat, motor means for moving the chair back or forward, and directional means, characterized in that said motor means comprise a motor actuating at minus a hydraulic pump which circulates a hydraulic fluid in a hydraulic circuit, so as to drive the wheels of the wheelchair.

 According to other characteristics of the wheelchair according to the invention: - it comprises a first hydraulic pump connected in series with a first hydraulic circuit supplying hydraulic receiving motors connected to each of the left wheels, a second hydraulic pump connected in series with a second hydraulic circuit supplying hydraulic receiving motors connected to each of the right wheels, and in addition a drawer control actuated by a lever, arranged between the hydraulic circuits, so as to bring or not the hydraulic fluid to the hydraulic receiving motors left and / or right wheels.

 - Preferably, the lever actuating the drawer control is provided with a hose making it possible to control its actuation by the chin of the user.

 - to move the wheelchair in a straight line, the control lever is actuated so as to move the right and left wheels simultaneously.

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 - to move the chair back in a straight line, the control lever is actuated so as to move the right and left wheels back simultaneously.

 - to move the chair to the right in forward gear, the control lever is actuated so as to move only the left wheels.

 - to turn the wheelchair to the left in forward gear, the control lever is actuated so as to move only the right wheels. the front wheels are directional and freestanding, so that they only turn to the right or to the left when they receive an appropriate stress in rotation.

 - The chair preferably also has an additional hydraulic circuit for supplying a jack arranged under the seat of the chair, so as to adjust the height of the seat hydraulically by the user.

 - the engine is a heat engine with a power of the order of 5 horsepower, the entire wheelchair having a total weight of less than 20 kilograms.

The invention will be described in more detail using the accompanying drawings, in which: FIG. 1 represents a block diagram of the wheelchair according to the invention, seen from above; 2 shows a block diagram of the wheelchair according to the invention, in side view; Figure 3 shows a block diagram of the main components of the wheelchair according to the invention, in a forward configuration; Figure 4 shows a block diagram of the main components of the wheelchair according to the invention, in a reverse configuration; FIG. 5 represents a block diagram of the main components of the wheelchair according to the invention, in a configuration for reversing between forward and reverse;
FIG. 6 represents a block diagram of the main components of the wheelchair according to the invention, in a

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 global configuration allowing forward, reverse and left-right control; FIG. 6a is a more detailed view of part of FIG. 6.

 Referring to Figure 1. There is shown in this figure a schematic top view of the wheelchair according to the invention, referenced 1. The wheelchair 1 has a frame 2 on which is fixed a seat 3. The frame is connected with four wheels 4a, 4b, 4c and 4d by means of axes of rotation 5 each carrying a respective hydraulic receiving motor 24a, 24b, 24c and 24d secured respectively to the wheels 4a, 4b, 4c, 4d. These hydraulic receiving motors 24a, 24b, 24c, 24d are for example made up of turbines capable of transforming the hydraulic energy which they receive, into mechanical energy which is then communicated to the wheels. Each reception motor has an interchangeable fluid inlet and outlet, so that the direction of arrival and exit of the hydraulic fluid determines the direction of rotation of the reception engine, and consequently of the wheel which is linked to it. Preferably, to optimize grip and rolling, the wheels 4a, 4b, 4c, 4d are wide, of small diameter, and at low pressure. Also preferably, the wheels are mounted by clipping, to facilitate their removal and their replacement. The wheelchair can therefore be easily stored in a car by one person. It should be noted that in order to obtain a simplified running gear as much as possible, the axes of rotation 5 are not articulated, but simply movable in rotation, so that the direction is given to the wheelchair by the direction of advance of the wheels and by their relative speed, a bit like on tanks. However, as a variant (not shown in the figures), it is possible to provide front wheels mounted on articulated axes, so that the wheels are directional, while remaining free, that is to say not subject to a direction. In this configuration, the front wheels are freestanding, that is to say they return to the upright position when they are not driven in front or rear rotation.

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 There has also been shown schematically an engine 6, which is a heat engine, located for example under or behind the seat 3. The transmission of motive energy by this engine 6 to the wheels 4 for the different driving situations will be detailed further. Let us also note the presence of a lever-type control member 7 (also called joystick in English terminology), the position of which actuates a drawer control (not shown) and thus determines the direction and the speed of rotation of the hydraulic reception motors 24, and consequently that of the wheels 4 which are integral therewith. Preferably, or at least as an option, provision may be made for the possibility of controlling the lever 7 from the chin or the head of the user, which may be prove useful to allow the use of the wheelchair by quadriplegic people. The realization of such a control offset is not of great technical difficulty, it can be easily carried out by the skilled person, in particular starting from of a flexible control cable, it will therefore not be described in detail.

 Referring now to Figure 2, showing the wheelchair 1 of Figure 1, but seen from the side. This figure shows a fuel tank 8 intended for supplying the engine 6, and located for example under the seat 3. There is also shown a telescopic mechanism 9 supporting the seat 3, so that it can be up (especially when the user wants to sit or stand up) and down (especially when the user is about to set the wheelchair in motion.

 Reference is made to FIG. 3 which shows in more detail a block diagram of the main components ensuring the propulsion and the direction of the wheelchair according to the invention, in a forward drive configuration. The hydraulic flow leaving the hydraulic pump and going towards the reception motors 24 is shown in solid lines and in broken lines the hydraulic flows returning from the reception motors 24 to the reservoir 14. The motor 6 shown diagrammatically has a motor axis 10 which

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 rotates continuously during the use of the wheelchair and actuates two hydraulic pumps 11, 12 connected to a hydraulic circuit 13, 15 which is established between a reservoir 14 of hydraulic fluid and the receiving motors 24 which drive the wheels 4. More precisely , a left hydraulic circuit 13 is established between an outlet of the hydraulic reservoir 14, the hydraulic pump 111 a hydraulic receiving motor 24b secured to the left front wheel 4b, and a hydraulic receiving motor integral 24a secured to the left rear wheel (not shown). Similarly, a straight hydraulic circuit 15 is established between an outlet of the hydraulic tank 14, the hydraulic pump 12, a hydraulic receiving motor 24d secured to the right front wheel (not shown), and a hydraulic receiving motor 24c secured to the right rear wheel (not shown). Between the two left and right hydraulic circuits 13 and 15 is connected a miniaturized drawer control actuated by means of a lever (Joystick) 17 and which thus makes it possible to adjust the flow rate of the left 11 and right 12 pumps, which amounts to set the respective forward speed of the left and right wheels. Thus, the lever 17 actuates a miniaturized drawer control which makes it possible to regulate the flows in each hydraulic circuit, as a function of the position of the lever 17. Such drawer controls are well known in the field of hydraulics.

 The operation is then as follows: the motor 6 being running, it actuates the hydraulic pumps 11, 12 which circulate the hydraulic fluid in the circuits 13, 15, towards the reception motors 24, then from these in return towards the reservoir 14. The drawer control is connected in parallel between the two left 13 and right 15 circuits, so as to receive the input from the pumps 11, 12, and at the output it is connected to the reservoir 14.

Thus, the drawer control 16 organizes a controlled leak to bring the hydraulic fluid back to the reservoir 14 (lines shown in broken lines). The position of the lever 17 will allow to equalize or on the contrary

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 to unbalance the leaks between the right circuit 15 and the left circuit 13. Identical leaks on both sides will correspond to an identical power supplied to the right and left reception motors, so that the wheelchair 1 will move in a straight line. A greater return leak in the right circuit 15 will make it possible to bring more hydraulic power to the reception motors on the left side, so that the left wheels will move faster, and the chair will turn to the right. Conversely, a greater return leak in the left circuit 13 will make it possible to bring more hydraulic power to the reception motors on the right side, so that the right wheels will move faster, and the chair will turn to the left.

 Referring now to Figure 4. In this figure, there is shown a block diagram of the main components providing propulsion and steering of the wheelchair according to the invention, in a reverse configuration. In this configuration, the hydraulic circuit comprises a drawer control 26 similar to that 16 in FIG. 3, this control 26 being actuated by means of a lever referenced 27. However, the outputs of the pumps 11, 12 are here connected through the conduits 27, 28, 29, 30 to the second inputs of the respective receiving motors 24b, 24a, 24d, 24c, so that the corresponding wheels will turn back, and the wheelchair moves back in a straight line. To veer back towards the right side or the left side, the user will act on lever 27 to favor the flow on the right side (to reverse by veering to the left), or to favor the flow on the left side (to reverse in veering to the right).

 Reference is now made to FIG. 5. In this figure, only the left part of the hydraulic circuit, allowing the drive of the left reception motors 24a, 24b has been shown, it being understood that the right part is symmetrical. In this figure, there is shown a control configuration with drawers 36 allowing, depending on the position of the control lever (not

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shown), to act on the valves 36a and 36b of the drawer control 36, in order to reverse the direction of the hydraulic flow which attacks the input of each receiving motor. For example, when the valves 36a, 36b are in the configuration shown, the hydraulic flow coming from the pump 11 arrives at the orifice referenced El of the reception motor 24a, and exits through the orifice E2, which corresponds to a first direction of rotation of the receiving motor 24a. Conversely, when the valves 36a, 36b are in the opposite configuration to that shown, the hydraulic flow coming from the pump 11 arrives at the orifice referenced E2 of the reception motor 24a, and exits through the orifice El, which corresponds to the reverse direction of rotation of the receiving motor 24a. Thus, it is possible, depending on the position of the lever of the drawer control 36, to select the forward or reverse gear, which for the rest operates as explained in relation to FIGS. 3 and 4
We now refer to Figure 6. In this figure, there is shown a summary of the operation of the hydraulic circuit control, when all the components are connected as shown in Figures 3 to 5. For this purpose, the drawer controls 16, 26, 36 above are combined into a global control 46 so that they can be actuated by a single global selection lever shown diagrammatically by the broken line 47 making it possible to select forward or reverse, the right turn or the turn to the left. The action on the lever 47 and the effect which results therefrom are summarized in a synthetic manner in the detail view 6a, which represents the rod of the lever 47 (joystick), and various examples of position, with the resulting movement for the wheelchair 1 according to the invention. Thus, by pushing the lever 47 forward (direction referenced AV), the wheelchair is moved forward in a straight line. By pushing the lever backwards and to the left (direction referenced ARG), the chair is moved diagonally backwards and to the left. And so on for the other directions: AVD (front right), AVG

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 (front left), ARD (rear left), G (left), and D (right).

 From the above, it follows that the invention achieves its objectives, and makes it possible to propose a wheelchair of simple and light structure, since it comprises neither electric batteries, nor brakes, nor gearbox, nor steering gimbals. All mobility is ensured by a hydraulic circuit allowing the driving energy to be applied to the wheels by means of a hydraulic circuit, and this selectively. The circulation of the hydraulic fluid is ensured by a hydraulic pump actuated by a motor, which is preferably a small thermal engine with a power of the order of 5 horsepower supplied from a small fuel tank.

Claims (10)

 CLAIMS 1. Motorized wheelchair (1), comprising a chassis (2), a seat (3), motor means (6,11, 12,13, 15) for moving the wheelchair back or forward, and means directional (16; 26; 36; 46), characterized in that said motor means comprise a motor (6) actuating at least one hydraulic pump (11,12) which circulates a hydraulic fluid in a hydraulic circuit (13,15) , so as to drive the wheels (4a, 4b, 4c, 4d) of the wheelchair (1). 2. Wheelchair (1) according to claim 1, characterized in that it comprises a first hydraulic pump (11) connected in series with a first hydraulic circuit (13) supplying hydraulic receiving motors (24a, 24b) connected to each of the left wheels (4a, 4b), a second hydraulic pump (12) connected in series with a second hydraulic circuit (15) supplying receiving hydraulic motors (24c, 24d) connected to each of the right wheels (4c, 4d), and in addition a drawer control (16,26, 36,46) actuated by a lever (7; 17; 27; 47), arranged between the hydraulic circuits (13,15), so as to bring or not the hydraulic fluid to the hydraulic receiving motors (24) of the left (4a, 4b) and / or right (4c, 4d) wheels. 3. Wheelchair (1) according to claim 2, characterized in that the lever (7; 17, 27; 47) actuating the drawer control (16; 26; 36; 46) is provided with a flexible allowing to control its actuation by the chin of the user. 4. Wheelchair (1) according to any one of the preceding claims, characterized in that to advance the wheelchair in line <Desc / Clms Page number 12>  right, the control lever (7; 17; 27; 47) is actuated so as to advance the right (4a, 4b) and left (4c, 4d) wheels simultaneously. 5. Wheelchair (1) according to any one of the preceding claims, characterized in that to move the chair back in a straight line, the control lever (7; 17; 27; 47) is actuated so as to move the right (4a, 4b) and left (4c, 4d) wheels simultaneously. 6. Wheelchair (1) according to any one of the preceding claims, characterized in that to turn the chair to the right in forward gear, the control lever (7; 17; 27; 47) is actuated so as to advance only the left wheels (4c, 4d). 7. Wheelchair (1) according to any one of the preceding claims, characterized in that, in order to turn the chair to the left in forward motion, the control lever (7; 17; 27; 47) is actuated so as to advance only the right wheels (4c, 4d). 8. Wheelchair (1) according to any one of the preceding claims, characterized in that the front wheels (4b, 4d) are directional and self-supporting, so as to not turn to the right or to the left only when they receive a stress. suitable for rotation. 9. Wheelchair (1) according to any one of the preceding claims, characterized in that it further comprises an additional hydraulic circuit for supplying a jack (9) arranged under the seat (3) of the chair, so as to adjust hydraulically the seat height (3) by the user. 10. Wheelchair (according to any one of the preceding claims, characterized in that said motor (6) is a heat engine of a <Desc / Clms Page number 13>  power of the order of 5 horses, the whole chair having a total weight of less than 20 kilograms.