GB2089300A

GB2089300A - Control means for electric vehicle

Info

Publication number: GB2089300A
Application number: GB8137596A
Authority: GB
Original assignee: BIDDLE ENG CO Ltd
Current assignee: BIDDLE ENG CO Ltd
Priority date: 1980-12-13
Filing date: 1981-12-14
Publication date: 1982-06-23
Also published as: GB2089300B

Abstract

An electric vehicle, in particular a wheelchair for use by invalids, is provided with a "twist-grip" control (34, 35) rotatable about its longitudinal axis in clockwise and anticlockwise directions from an "at rest" position, such rotational movement from its "at rest" position causing a differential in the power supplied to motors driving respective sides of the wheelchair to cause the wheelchair to turn either to the left or to the right. A speed control lever (61) may be mounted on the "twist-grip" (34, 35) to alter the speed at which the wheelchair may be driven. The twist-grip control (34, 35) and speed control lever (61) may operate a plurality of switches or influence a solid state control circuit to control the amount of power supplied to the motors driving the wheelchair. <IMAGE>

Description

SPECIFICATION Control means The present invention relates to control means for controlling the operation of an electrically powered vehicle.

The invention has particular, but not exclusive, application to the control of an electrically powered wheelchair for use by invalids, of the type which is adapted to be controlled by an attendant walking behind the wheelchair, such a wheelchair is hereinafter referred to as "an attendant controlled wheelchair".

The control means of the present invention is particularly adapted for use with electrically powered vehicles in which the steering of the vehicle is caused by, or assisted by supplying different amounts of power to driven wheels on respective sides of the vehicle. In the case of an electrically powered vehicle having a driven wheel on each side, each such driven wheel being supplied with power by a respective electrical motor, if only one motor is supplied with power the vehicle will tend to turn in a direction away from the side of the powered motor. For example, if a powered wheel on the left-hand side of the vehicle is unenergised and a powered wheel on the right-hand side is energised, the vehicle will tend to turn in an anti-clockwise direction.

It is an object of the present invention to provide improved control means in or for an electrically powered vehicle.

According to one aspect of the present invention, we provide control means in or for an electrically powered vehicle, said control means including an elongate manually operable member, adapted for mounting on the vehicle for at least limited rotational movement about a first axis aligned with its longitudinal axis in a first rotational direction from an "at rest" position to influence electrical energy supplied to a motor or motors adapted to motivate the vehicle, to cause the vehicle to turn in one direction, and in a second opposite rotational direction from said "at rest" position, to influence the electrical energy supplied to the motor or motors to cause the vehicle to turn in the opposite direction.

The manually operable member may be of tube-like configuration, and conveniently is of ''twist-grip" form.

Preferably biassing means are provided to bias said manually operable member into said "at rest" position.

Preferably speed control means are provided and adapted for mounting so as to be operable in association with said manually operable member in a manner such that said speed control means and said manually operable member may be operated together.

Preferably said speed control means is mounted for pivotal movement relative to said manually operable member.

Preferably said manually operable member has pivotally mounted thereon speed control means, said speed control means being adapted for pivotal movement from an "at rest" position in which no power is supplied to the motors, to an operative position in which power is supplied to the motors, there being a differential in the power supplied to the motors on movement of said manually operable member in either rotational direction from its "at rest" position.

Preferably said manually operable member is rotational about an axis which is approximately parallel to or slightly inclined to the ground on which the vehicle is supported.

Such an axis will hereinafter be referred to as "generally horizontal".

The manually operable member is preferably a tubelike part co-axially mounted on a further tube-like part, said rotational movement being provided about the respective longitudinal axes of said tube-like parts. Conveniently, said manually operable member is of "twist-grip" form.

Said means for biasing the manually operable member to its "at rest" position may be provided internally of the manually operable member and can conveniently comprise cooperating cam parts, one cam being associated with the manually operable member, the other with the further tube-like part, the arrangement being such that movement of the manually operable member from its "at rest" position causes movement of one of said cam parts axially along said rotational axis, such axial. movement being adapted to cause compression of a resilient means such as a helical spring.

Preferably said speed control means is adapted to cause operation of a plurality of switch means, which switch means cause the completion of a circuit whereby electrical energy is supplied to the motors, or is disconnected therefrom, as the case may be, operation of said manually operable member from its "at rest" position influencing the operation of said switch means in a manner to cause more electrical energy to be supplied to a motor or motors driving one side of the vehicle than the other.

According to another aspect of the present invention, we provide an electric vehicle having at least one driven wheel on each side of the vehicle, each driven wheel being provided with and driven by a respective motor and control means comprising an elongate manually operable member mounted for at least limited rotational movement about its longitudinal axis from an "at rest" position in a first rotational direction, whereby one motor is supplied with more electrical energy than the other, and in a second rotational direction from said "at rest" position, in which position said other motor is supplied with more electrical energy than said one motor.

Preferably said vehicle comprises an electrically powered wheelchair for use by invalids having at least one driven wheel on each side of the wheelchair, said driven wheel or wheels being driven by electric motors, at least one motor being associated with each side of the wheelchair, speed control means adapted to connect the motors to, or disconnect the motors from, a supply of electrical energy, and control means comprising an elongate manually operable member mounted about a generally horizontal axis for rotation about said axis from an "at rest" position in a first rotational direction to cause more electrical energy to be supplied to the motor driving one side of the wheelchair than the other, and in a second rotational direction to cause more electrical energy to be supplied to the motor driving the other side of the wheechair.

The wheelchair may be an attendant controlled wheelchair having at least one electric motor on each side of the wheelchair driving a wheel or wheels on respective sides of the wheelchair, said wheelchair including a pair of elongate handles extending from the rear of the wheelchair in a manner such that an attendant can hold onto the wheelchair, one of said elongate handles being mounted for at least limited rotation about its longitudinal axis from an "at rest" position in a first rotational direction to enable more power to be supplied to one motor than the other to cause the wheelchair to turn in one direction, and in the opposite rotational direction from its "at rest" position to enable more power to be supplied to the other of the motors, to cause the wheelchair to turn in the other direction.

The invention will now be described in more detail by way of example only, with reference to the accompanying drawings wherein: Figure 1 is a perspective view of a wheelchair for use by invalids; Figure 2 is a view, partly in section, of the control means; Figure 3 is another view of the control means shown in Fig. 2; Figure 4 shows different views of one of the cam parts of the biasing means; Figure 5 shows views of the other of the cam parts of the biasing means; Figure 6 shows views of an end part of the control means.

Referring first to Fig. 1, the wheelchair illustrated comprises a frame construction which includes a pair of side frames 10 and 11, each of the frames 10 and 11 including a back upright member 1 2 of tubular construction, a front upright member 1 3 also of tubular construction and a pair of tubular members 1 4 and 1 5 interconnecting the front and back members 12.

Three linkages 16, only one of which is shown, interconnect the frame assemblies 10 and 11. Each link 1 6 includes a pair of pivotally connected links which can be moved through an overcentre positionto the position shown in Fig. 1 in which they serve to maintain the side frames 10 and 11 in spaced relationship.

An arm rest 1 9 having a pad 20 is attached to each of the side frames 10 and 11.

A sheet 21 of flexible material is secured between the back members 1 2 and the side frames to form a back rest. A further sheet 22 of flexible material is secured between the upper tubular members 1 4 to provide the seat portion of the chair and an additional sheet 23 also of flexible material is secured between the lower tubular members 1 5 to provide a parcel shelf.

Footrests 24 are connected by clips 25 to support members 26 which are connected to the frame members 1 3 of the side frames 10 and 11. The front wheels of the wheelchair comprise a pair of castor wheels 29 pivotally secured at the lower ends of the tubular front members 1 3.

The rear wheels of the wheelchair comprise a pair of driving wheels 31, only one of which is shown, mounted at the rear of the chair.

The wheels can have either pneumatic tyres or solid rubber tyres. The driving wheels 31 are driven by respective electric motors 32L and 32R which may be of a permanent magnet type and mounted relative to the wheel as described and claimed in British Patent Specification 1,198,905.

Extending from the rear of the wheelchair are a pair of handles 33 by means of which the wheelchair can be controlled by an attendant walking behind the wheelchair. Each of the handles 33 have a grip 34.

Secured to one of the uprights 1 2 there is a control box 37. The control box 37 is provided with an "on/off" switch 38.

The control box 37 is connected to batteries 35 and motors 32 through cables 39 and 40.

The handle 33 connected to the control box 37 will now be described in more detail with reference to Figs. 2 and 3.

The control means comprises an elongate tube-like member 35 which is mounted coaxially on the handle 33 in a manner such that limited relative rotational movement between the tube-like part 35 and the further tube-like handle part 33 may take place about axis 41. The control member 35 is biased to an "at rest" position by biasing means generally indicated at 42, which biasing means comprises a first cam part 43 rotationally fixed but axially movable relative to the member 35, and a second cam part 44 which is both axially and rotationally fixed in the further tube-like handle part 33.

The control member 35 is secured to the handle 33 by means of threaded fastener 45, the head of which engages an end plug 46 secured to the end of the tube-like part form ing the control member 35. The threaded part of the fastener 45 engages the second cam part 44.

The first cam part is illustrated more clearly in Fig. 4 and has a pair of flat surfaces 47 which can slide over flat surfaces 48 provided on the end cap 46 and a V-shaped cam surface 49.

The second cam part as shown in Fig. 5 has a cylindrical surface 50 by means of which it is secured in the tube-like handle part 33 and a V-shaped cam face 51. A through bore 52 is provided into which a fastener 45 passes and threadedly engages the cylindrical surface thereof.

A helical spring 53 is provided and which acts between the first cam part 43 and the end cap 46 to cause the first cam part 43 to be positioned relative to the second cam part 44 as shown in Fig. 2, and biassing the cam part 43 against any movement away from that position.

Any rotational movement of the control member 35 relative to the tube-like handle 33 about the axis 41 will cause rotational movement between the cam parts 43 and 44 which in turn will cause axial movement between the cam parts 43 and 44 thus compressing the helical spring 53. When the surfaces 54 of the first cam part abut the surfaces 55 of the end cap, any further rotation in that direction will be prevented.

The assembly thus allows for limited rotational movement from the "at rest" position in either rotational direction.

Pivotally mounted on the control member 35 about pivotal axis 60 is a lever 61 having an "on" position shown in bold outline and an "off" position shown in dotted outline.

Biasing means may be provided to bias the lever 61 to its "off" position, such biasing means may comprise the weight distribution of the lever itself whereby, unless influenced by external forces other than gravity, it will take up the position shown in dotted outline.

Resilient bearing means such as a spring may also or alternatively be provided.

Connected to the lever 61 is an operating plate 62. The operating plate 62 being adapted when the lever 61 is in its "on" position to cause operation of microswitches 63 and 64, arrangement being such that as the lever 61 is brought nearer to the control member 35 i.e. is "squeezed", the operating plate 62 presses down on the buttons 65 and 66 of respective microswitches 63 and 64.

Pressing down the switches 65 and 66 will cause power to be supplied to the two motors 32L and 32R thus causing the wheelchair to move in a forward straight ahead direction.

The operating plate 62 is connected to the lever 61 through a universal joint 56 and the plate 62 is "guided" in its movement by a spigot 57 attached to plate 62 and which is guided by a bush 58 having through bore 59 with chamfered ends to allow for rocking of the plate 62.

In an alternative arrangement, the universal joint 56 can be replaced by a flexible joint such as a rubber or plastics joint.

If the control member 35 is rotated in a clockwise direction while the lever 61 is depressed to cause movement of the wheelchair, the plate 62 will be moved such that the button 65 of microswitch 63 is still depressed or possibly depressed even further while the button 66 of microswitch 64 is no longer depressed or is depressed to a lesser extent.

If the microswitch 64 is connected to the right-hand motor and the microswitch 63 is connected to the left-hand motor, and they operate to either interrupt or connect the power supplied to said motor, then clockwise rotation of the operating member 35 will cause the wheelchair to turn to the right and similarly anti-clockwise rotation of the operating member 35 will have the effect of maintaining pressure on the button 66 or increasing the pressure and depressing the button further while decreasing the pressure on button 65 or removing the plate 62 completely out of contact therefrom, thus providing greater power to the motor 32R and turning the vehicle to the left.

The control box 37 is shown as being connected to the upright 1 2 by means of a plate 70 by means of fasteners 71 and 72.

However it is envisaged that it may be placed at any other suitable alternative position.

It is not essential that the control box is placed in proximity to the control member 35 since the microswitches or other switch means, whether mechanical or electronic, be operated by remote control, for example by means of a Bowden cable in response to operation of the control member 35 and lever 61.

It is further envisaged that the control member 35 could rotate and cause rotation of the spindle of a variable resistor which in turn would alter the distribution of power supplied to the motors 32L and 32R on respective sides of the wheelchair through an electronic control circuit. Similarly, the control lever 61 could also cause operation of one or more variable resistors to cause power to be supplied to the motors in an infinitely variable manner from an "off" position to a position of maximum power.

The microswitches 63 and 64 shown, on the control box 37, may each have more than one pair of contacts and be operable so that when the buttons 65 and 66 are depressed by a certain extent, a first pair of contacts is operated, and then when the buttons of 65 and 66 are depressed further, a second pair of contacts are operated so that the power supplied to the motors driving the wheelchair can be increased in stages to enhance smoother operation in use of the wheelchair.

Claims

1. Control means in or for an electrically powered vehicle, said control means including an elongate manually operable member, adapted for mounting on the vehicle for at least limited rotational movement about a first axis aligned with its longitudinal axis in a first rotational direction from an "at rest" position to influence electrical energy supplied to a motor or motors adapted to motivate the vehicle, to cause the vehicle to turn in one direction, and in a second opposite rotational direction from said "at rest" position, to influence the electrical energy supplied to the motor or motors to cause the vehicle to turn in the opposite direction.

2. Control means as claimed in Claim 1 wherein said manually operable member is of "twist-grip" form.

3. Control means as claimed in Claim 1 or Claim 2 wherein biassing means are provided to bias said manually operable member into said "at rest" position.

4. Control means as claimed in any one of the preceding claims wherein speed control means are provided and adapted for mounting so as to be operable in association with said manually operable member in a manner such that said speed control means and said manually operable member may be operated together.

5. Control means as claimed in Claim 4 wherein said speed control means is mounted is mounted on, for pivotal movement relative to, said manually operable member.

6. Control means as claimed in Claim 5 wherein said speed control means is adapted for pivotal movement from an "at rest" position in which no power is supplied to the motors, to an operative position in which power is supplied to the motors, there being a differential in the power supplied to the motors on movement of said manually operable member in either rotational direction from its "at rest" position.

7. Control means as claimed in any one of the preceding claims wherein said manually operable member is adapted for mounting or is mounted on said vehicle for rotation about an axis which is approximately parallel to or slightly inclined to the ground on which said vehicle is supported.

8. Control means as claimed in any one of the preceding claims wherein the manually operable member comprises a tube-like part co-axially mounted on a further tube-like part, said rotational movement being provided about the respective longitudinal axes of said tube-like parts.

9. Control means as claimed in Claim 8 wherein means are provided for biasing the manually operable member to its "at rest" position, said means being provided internally of the manually operable member and comprising co-operating cam parts, one cam being associated with the manually operable member, the other with the further tube-like part, the arrangement being such that movement of the manually operable member from its "at rest" position is adapted to cause movement of one of said cam parts axially along said rotational axis, such axial movement being adapted to cause compression of a resilient means.

10. Control means as claimed in Claim 4 wherein said speed control means is adapted to cause operation of a plurality of switch means, which switch means cause the completion of a circuit whereby electrical energy is supplied to the motors, or is disconnected therefrom, operation of said manually operable member from its "at rest" position influencing the operating of said switch means in a manner to cause more electrical energy to be supplied to a motor or motors driving one side of the vehicle than the other.

11. Control means as claimed in Claim 10 wherein said manually operable member is adapted on movement from its "at rest" position to cause of the plate member adapted to cause operation of said switch means, the plate member being mounted in a manner such that movement of said manually operable member causes rocking of said plate member to operate said switch means.

1 2. Control means as claimed in Claim 11 wherein said manually operable member is connected to said plate member through a universal joint.

1 3. Control means as claimed in Claim 11 or Claim 1 2 wherein said speed control means is also adapted to cause movement of said plate member in a direction such that, when said manually operable member is in its "at rest" position, said switch means are operated to cause equal amounts of power to be supplied to motors on respective sides of the vehicle.

14. An electric vehicle having at least one driven wheel on each side of the vehicle, each driven wheel being provided with and driven by a respective motor and control means comprising an elongate manually operable member mounted for at least limited rotational movement about its longitudinal axis from at "at rest" position in a first direction, whereby one motor is supplied with more electrical energy than the other, and in a second rotational direction from said "at rest" position, in which position said other motor is supplied with more electrical energy than said one motor.

1 5. An electric vehicle as claimed in Claim 1 4 wherein said vehicle comprises an electrically powered wheelchair for use by invalids.

16. An electric vehicle as claimed in Claim 1 5 wherein said wheelchair comprises an attendant controlled wheelchair having at least one electric motor on each side of the wheel chair driving a wheel or wheels on respective sides of the wheelchair, said wheelchair including a pair of elongate handles extending from the rear of the wheelchair in a manner such that an attendant can hold onto the wheelchair, one of said elongate handles being mounted for at least limited rotation about its longitudinal axis from an "at rest" position, in a first rotational direction to enable more power to be supplied to one motor than the other to cause the wheelchair to turn in one direction, and in the opposite rotational direction from its "at rest" position to enable more power to be supplied to the other of the motors, to cause said wheelchair to turn in the other direction.

1 7. In or for an electric vehicle control means substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

1 8. An electrically powered wheelchair for use by invalids substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

1 9. A wheelchair for use by invalids including any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.