GB2184987A - Wheelchair drive - Google Patents

Wheelchair drive Download PDF

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Publication number
GB2184987A
GB2184987A GB08530961A GB8530961A GB2184987A GB 2184987 A GB2184987 A GB 2184987A GB 08530961 A GB08530961 A GB 08530961A GB 8530961 A GB8530961 A GB 8530961A GB 2184987 A GB2184987 A GB 2184987A
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GB
United Kingdom
Prior art keywords
wheelchair
worm
wheel
drive
wheels
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB08530961A
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GB8530961D0 (en
GB2184987B (en
Inventor
Jeremy Joseph Fry
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Individual
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Individual
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Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to GB08530961A priority Critical patent/GB2184987B/en
Publication of GB8530961D0 publication Critical patent/GB8530961D0/en
Publication of GB2184987A publication Critical patent/GB2184987A/en
Application granted granted Critical
Publication of GB2184987B publication Critical patent/GB2184987B/en
Expired legal-status Critical Current

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
    • A61G5/00—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs
    • A61G5/04—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs motor-driven
    • A61G5/041—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs motor-driven having a specific drive-type
    • A61G5/042—Front wheel drive
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
    • A61G5/00—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs
    • A61G5/04—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs motor-driven
    • A61G5/041—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs motor-driven having a specific drive-type
    • A61G5/045—Rear wheel drive
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
    • A61G5/00—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs
    • A61G5/10—Parts, details or accessories
    • A61G5/1051—Arrangements for steering
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K1/00—Arrangement or mounting of electrical propulsion units
    • B60K1/02—Arrangement or mounting of electrical propulsion units comprising more than one electric motor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/04—Arrangement or mounting of transmissions in vehicles characterised by arrangement, location, or kind of gearing
    • B60K17/043—Transmission unit disposed in on near the vehicle wheel, or between the differential gear unit and the wheel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L15/00—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles
    • B60L15/20—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L53/00—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
    • B60L53/10—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles characterised by the energy transfer between the charging station and the vehicle
    • B60L53/14—Conductive energy transfer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L58/00—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles
    • B60L58/10—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries
    • B60L58/18—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries of two or more battery modules
    • B60L58/19—Switching between serial connection and parallel connection of battery modules
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05G—CONTROL DEVICES OR SYSTEMS INSOFAR AS CHARACTERISED BY MECHANICAL FEATURES ONLY
    • G05G9/00—Manually-actuated control mechanisms provided with one single controlling member co-operating with two or more controlled members, e.g. selectively, simultaneously
    • G05G9/02—Manually-actuated control mechanisms provided with one single controlling member co-operating with two or more controlled members, e.g. selectively, simultaneously the controlling member being movable in different independent ways, movement in each individual way actuating one controlled member only
    • G05G9/04—Manually-actuated control mechanisms provided with one single controlling member co-operating with two or more controlled members, e.g. selectively, simultaneously the controlling member being movable in different independent ways, movement in each individual way actuating one controlled member only in which movement in two or more ways can occur simultaneously
    • G05G9/047—Manually-actuated control mechanisms provided with one single controlling member co-operating with two or more controlled members, e.g. selectively, simultaneously the controlling member being movable in different independent ways, movement in each individual way actuating one controlled member only in which movement in two or more ways can occur simultaneously the controlling member being movable by hand about orthogonal axes, e.g. joysticks
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
    • A61G2203/00—General characteristics of devices
    • A61G2203/10—General characteristics of devices characterised by specific control means, e.g. for adjustment or steering
    • A61G2203/14—Joysticks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2200/00—Type of vehicles
    • B60L2200/34—Wheel chairs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2220/00—Electrical machine types; Structures or applications thereof
    • B60L2220/40—Electrical machine applications
    • B60L2220/42—Electrical machine applications with use of more than one motor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2220/00—Electrical machine types; Structures or applications thereof
    • B60L2220/40—Electrical machine applications
    • B60L2220/46—Wheel motors, i.e. motor connected to only one wheel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/10—Vehicle control parameters
    • B60L2240/12—Speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2260/00—Operating Modes
    • B60L2260/20—Drive modes; Transition between modes
    • B60L2260/28—Four wheel or all wheel drive
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/64—Electric machine technologies in electromobility
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/70—Energy storage systems for electromobility, e.g. batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/7072—Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/72—Electric energy management in electromobility
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02T90/10—Technologies relating to charging of electric vehicles
    • Y02T90/14—Plug-in electric vehicles

Abstract

A wheelchair has more than two wheels (7) and a separate drive for each wheel (7). Each drive is preferably in the form of an electric motor (1) which is preferably connected to the wheel (7) by means of a worm (5) and a worm-wheel (4). The helix angle of the worm (5) and worm-wheel (4) is preferably less than 8 DEG for automatic braking of the wheels (7), and preferably between 7 DEG and 7 DEG 50' for rapid but controlled braking. A preferred helix angle is substantially 7 DEG 35'. <IMAGE>

Description

SPECIFICATION Wheelchair drive The present invention relates to a powered wheelchair, particularly but not exclusively to an electrically-powered wheelchair.
It is known to provide a wheelchair in which either the front or rear wheels are driven, e.g.
by an electric motor. The non-driven wheels are usually arranged as castors. Furthermore, a wheelchair, in order to be manoeuvrable in confined spaces, has a relatively short wheel base and relatively small wheels. Consequently, it can be difficult and often impossible to drive such a wheelchair over surfaces which are not flat or which are uneven, such as grass or gravel.
Furthermore, a vehicle with a short wheel base is particularly prone to weight transference when climbing or descending a hill and dependent on whether the drive is on the rear wheels or the front wheels, the tractive and braking effect of the drive wheels reduces as the weight is transferred from them.
In a wheelchair as described above, when traversing a slope the castor wheels, whether at the front or the back, will always turn down the hill under the influence of the weight of the wheelchair and its occupant, and it is, therefore, difficult if not impossible for such a wheelchair to traverse a slope or indeed to change direction on steep hills.
The invention provides a wheelchair having more than two wheels and a drive for each wheel.
Preferably, each drive is in the form of an electric motor directly connected to a respective one of the wheels by means of a worm and worm wheel.
Automatic braking of all four wheels may be provided if the helix angle of the worm is less than 8, preferably 7" 35' so that the wheelchair comes to a rapid but controlled stop.
Such an angle can be critical, and depending upon the materials used for the worm and worm-wheel and the lubricant, may be between 6 and 8".
Braking of all four wheels makes for a much more stable chair particularly when on a hill.
An embodiment of the invention will now be described with reference to the accompanying drawings, wherein: Figure 1 is a part-sectional front view of an electric motor drive of a front-left hand wheel of a wheelchair; Figure 2 is a part-sectional side view of the electric motor drive of Figure 1, Figure 3 is a perspective part-sectional view of a joystick control assembly, Figure 4 is an exploded view of the joystick control assembly of Figure 3, and Figure 5 is a circuit diagram for the wheelchair.
in Figure 1, a drive assembly comprising an electric motor 1 is pivotally mounted at a corner of a substantially rectangular wheelchair base 2 by means of a bolt 3. The motor 1 drives a worm 5 mounted in bearings 5' and engaging a worm-wheel 4 mounted in bearings 4' on one end of a spindle 6. A wheel 7 having a cushion drive and a tyre 9 is mounted on the spindle 6 and is driven via a pin 10. In order to obtain a freewheel condition, e.g.. to allow the wheelchair to be pushed, the pin 10 is removed, the wheel 7 is slid towards the worm-wheel 4, and the pin 10 is replaced.
The pivotal mounting of the motor 1 allows the wheel 7 to turn relative to the wheelchair base 2. Preferably, the pivotal mounting is positively controlled, so that the wheel 7 is steered, e.g. via a sprocket plate 11, as described in my copending application entitled "Wheelchair Steering".
The upper end of the motor is provided with wedge-shaped plates 12, 12' (Figs. 1 and 2) so that the point of contact of the tyre 9 lies on the vertical axis Z through the bolt 3, thereby avoiding wheel scuffing.
If the helix angle of the worm 5 is less than 8', when power to the motor 1 is switched off, the wheel 7 will be automatically braked.
In order to ensure that the braking is not too slow or too rapid, the helix angle is from 7" to 7 50'. With a helix angle of 7"35' braking will be rapid but controlled. At this angle the worm and worm-wheel are only self-locking when stationary.
In order to allow folding of the wheelchair, the drive assembly is foldable against the underside of the base 2. To this end, the wedge-shaped plate 12, is pivotally mounted by means of a hinge pin 13 to a hinge plate 14 having a slot 15. The wedge-shaped plate 12 has a shoulder 16 engageable by means of a catch 17 slidable in the slot 15 and biased into the position as shown in Figure 1. When the catch 17 is slid in the slot 15 out of engagement of the shoulder 16, the drive assembly may be hinged in a clockwise direction in Figure 1 about the hinge pin 13 to abut the underside of the base 2, where it may be held by any convenient means.
It will be clear that a motor is provided at each of the other corners of the base 2 in a similar manner to the motor 1 of Figures 1 and 2.
The motors 1 are controlled via relays (described below) by means of a joystick assembly as shown in Figures 3 and 4 comprising a joystick 18 and a swash plate 19 movable in a gimbal ring 20 pivotally mounted on pivots 21 in a housing 22. The joystick 18 is mounted on an axle 23 held between two rocker plates 23' which in turn are rigidly connected to the swash plate 1 9 and carry a plurality of points 24. A plurality of resilient metal fingers or terminals 25 are carried by the swash plate 19 to engage the points 24 on movement of the joystick 18, so as to provide, via relays, various modes of movement of tne motors 1 and hence of the wheelchair.
When the joystick 18 is released, it is returned to a central position by means of a spring 18' acting on a suitably-shaped plate 18".
In Figure 5 unitary drives M, and M2 represent respectively the two front motors 1 and the two rear motors 1 connected, respectively, in parallel. A steering Motor SM is provided to provide four-wheel steering as described in my copending application 8530962 entitled "Wheelchair Steering" of the same date. Two batteries A and B are provided for powering the unitary drives M1, M2 and the steering motor SM. Relays r1 to r6 are provided for altering the connections between the unitary drives M1, M2, the batteries A, B and the steering motor SM, by means of the joystick 1 8. The part of Figure 5 within the chaindotted line is arranged within the joystick assembly.
Thus, for a first speed, relays r1 and r4 are closed by forward movement of the joystick 18 so that the unitary drives M1 and M2 are in series and the batteries A and B are in parallel. Further forward movement of the joystick 18 opens relay r1 so that the batteries A and B are now in series and the unitary drives M and M2 are driven at q second, higher speed.
In both the first and second speeds, when the unitary drives M1 and M2 are in series, both the front wheels and the rear wheels operate in full differential, respectively, i.e. if a front or rear wheel is held or goes slower, the other front or rear wheel, respectively, goes faster.
Still further forward movement of the joystick 18 closes relay r2 so that the unitary drives M, and M2 are now connected in parallel and are driven at a third speed (the batteries A and B are still connected in series through the open relay r1). In this third speed the parallel connection between the unitary drives eliminates differential drive between the front wheels and between the rear wheels of the wheelchair thereby eliminating wheel slip.
A first reverse speed is obtained by rearward movement of the joystick 18 to close relay r3 in addition to relays r1 and r4. Further rearward movement of the joystick 1 8 opens relay r1 (r3 and r4 remaining closed) so as to produce a second, faster reverse speed.
Sideways movement of the joystick 18 operates the steering motor as described in my copending application "Wheelchair Steering" already referred to.
A telephone-type jack plug 26 is provided for connecting the batteries A and B to a charger (not shown). Conveniently, the jack plug 26 is placed near the joystick so as to encourage the driver to charge the batteries regularly. Contacts 28, 29 of a jack plug socket ensure that the batteries A and B are automatically disconnected from the motors when the jack plug 26 is inserted in the socket.
It will be noted that in all speeds of the wheelchair, both forward and reverse, relay r4 is closed. A resistance 27 is provided to "short" all four electric motors, i.e. the unitary drives M1 and M2, when the relay r4 is open.
Thus, the value of the resistance 27 controls the braking force of the motors 1 (M1 and M2) when the joystick 18 is released and returned to the neutral position by means of the spring 18' acting on the plate 18". As explained above, with a helix angle of 7" 35', the worm 4 and the work-wheel 7 will be self-locking when the motors 1 (M1, M2) are stationary.
Operation of the steering motor SM via relays r5 and r6 is described in my copending application "Wheelchair Steering" already referred to.

Claims (15)

1. A wheelchair having more than two wheels and a drive for each wheel.
2. A wheelchair as claimed in claim 1, wherein each drive is in the form of an electric motor.
3. A wheelchair as claimed in claim 2, wherein each electric motor is directly connected to a respective one of the wheels by means of a worm and a worm-wheel.
4. A wheelchair as claimed in claim 3 wherein the helix angle of the worm and worm-wheel is less than 8' so that on switching off the drive the wheels are automatically braked.
5. A wheelchair as claimed in claim 4, wherein the helix angle of the worm is from 7 to 7'50' so that on switching off the drive the wheels are braked to bring the wheelchair to rest in a rapid but controlled manner.
6. A wheelchair as claimed in claim 4, wherein the helix angle is substantially 7" 35'.
7. A wheelchair as claimed in any one of claims 2 to 5, wherein control of the electric motors is by means of a joystick.
8. A wheel chair as claimed in claim 7, wherein the, joystick comprises a swash plate and gimbal ring construction.
9. A wheelchair as claimed in any one of claims 2 to 8 wherein relays are provided whereby the wheelchair may be driven at different speeds and in reverse.
10. A wheelchair as claimed in any one of claims 2 to 9, wherein the two front and the two rear electric motors, respectively, are connected in parallel to provide respective unitary drives.
11. A wheelchair as claimed in claim 10, wherein the unitary drives are connectable in series to provide differential drives for the front and rear wheels.
12. A wheelchair as claimed in claim 10 or 11, wherein the unitary drives are connectable in parallel to provide non-differential drive for the front and rear wheels.
13. A wheelchair as claimed in any one of claims 10 to 12, wherein a battery is provided for each unitary drive, the batteries being connectable in series or parallel to provide different speeds for the wheelchair.
14. A wheelchair as claimed in claim 13, wherein the unitary drives are connectable in series or parallel to provide different speeds for the wheelchair.
15. A wheelchair substantially as herein described with reference to the accompanying drawings.
GB08530961A 1985-12-16 1985-12-16 Wheelchair drive Expired GB2184987B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08530961A GB2184987B (en) 1985-12-16 1985-12-16 Wheelchair drive

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08530961A GB2184987B (en) 1985-12-16 1985-12-16 Wheelchair drive

Publications (3)

Publication Number Publication Date
GB8530961D0 GB8530961D0 (en) 1986-01-29
GB2184987A true GB2184987A (en) 1987-07-08
GB2184987B GB2184987B (en) 1989-01-18

Family

ID=10589830

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08530961A Expired GB2184987B (en) 1985-12-16 1985-12-16 Wheelchair drive

Country Status (1)

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GB (1) GB2184987B (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4852679A (en) * 1985-12-16 1989-08-01 Fry Jeremy J Wheelchair steering
GB2188889B (en) * 1986-04-01 1989-11-29 Spastics Soc Wheelchair
GB2244684A (en) * 1990-06-06 1991-12-11 Keith Richard Bound Electric four wheel drive wheelchair
EP0481591A1 (en) * 1990-10-17 1992-04-22 Sumitomo Heavy Industries, Ltd Rotary driving apparatus with internally-meshing planetary reduction gear including free-wheel mechanism
EP0960044A2 (en) * 1996-10-11 1999-12-01 Wheelchair Carrier, Inc. Lightweight motorized wheelchair
US6474434B1 (en) 1997-07-02 2002-11-05 Borringis Industrie Ag Drive wheel

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1198905A (en) * 1968-05-16 1970-07-15 Raymond George Biddle Improvements in Wheelchairs
US3814199A (en) * 1972-08-21 1974-06-04 Cleveland Machine Controls Motor control apparatus adapted for use with a motorized vehicle
GB1414134A (en) * 1971-11-24 1975-11-19 Cragg H Wheel chairs
GB1506571A (en) * 1975-05-16 1978-04-05 Biddle Eng Co Ltd Motorising of wheelchairs
GB1587184A (en) * 1976-06-17 1981-04-01 Harris J D Fodgen M F Wheelchairs
EP0026098A1 (en) * 1979-09-24 1981-04-01 Charles Mackintosh Power operated wheelchair
GB2134056A (en) * 1982-12-31 1984-08-08 Cecil James Watkins Folding, motorized wheelchair

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1198905A (en) * 1968-05-16 1970-07-15 Raymond George Biddle Improvements in Wheelchairs
GB1414134A (en) * 1971-11-24 1975-11-19 Cragg H Wheel chairs
US3814199A (en) * 1972-08-21 1974-06-04 Cleveland Machine Controls Motor control apparatus adapted for use with a motorized vehicle
GB1506571A (en) * 1975-05-16 1978-04-05 Biddle Eng Co Ltd Motorising of wheelchairs
GB1587184A (en) * 1976-06-17 1981-04-01 Harris J D Fodgen M F Wheelchairs
EP0026098A1 (en) * 1979-09-24 1981-04-01 Charles Mackintosh Power operated wheelchair
GB2134056A (en) * 1982-12-31 1984-08-08 Cecil James Watkins Folding, motorized wheelchair

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4852679A (en) * 1985-12-16 1989-08-01 Fry Jeremy J Wheelchair steering
GB2188889B (en) * 1986-04-01 1989-11-29 Spastics Soc Wheelchair
GB2244684A (en) * 1990-06-06 1991-12-11 Keith Richard Bound Electric four wheel drive wheelchair
EP0481591A1 (en) * 1990-10-17 1992-04-22 Sumitomo Heavy Industries, Ltd Rotary driving apparatus with internally-meshing planetary reduction gear including free-wheel mechanism
EP0960044A2 (en) * 1996-10-11 1999-12-01 Wheelchair Carrier, Inc. Lightweight motorized wheelchair
EP0960044A4 (en) * 1996-10-11 2001-05-02 Wheelchair Carrier Inc Lightweight motorized wheelchair
US6474434B1 (en) 1997-07-02 2002-11-05 Borringis Industrie Ag Drive wheel

Also Published As

Publication number Publication date
GB8530961D0 (en) 1986-01-29
GB2184987B (en) 1989-01-18

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