US3566986A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-propelled wheelchair
Assignee: Individual
•
Filing: 1969-05-15
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Granted: 1971-03-02
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Expires: 1989-05-15
Abstract
Abstract A pair of nonsteerable main wheels are disposed at opposite sides of the frame of the wheelchair. A drive unit is disposed at the rear of the frame and is swingably interconnected therewith. This drive unit includes a drive motor and a pair of driving wheels. A self-braking driving transmission connects the motor with the driving wheels. A steering motor is also incorporated in the unit and a self-braking transmission connects the steering motor with a member fixed to the frame to cause swinging movement of the unit with respect to the frame.
Inventors
- 👤 Per Edward Carl Udden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:11
CPC Classifications
A; A61; A61G; A61G5/00; A61G5/04; A61G5/041; A61G5/045; A61G5/10; A61G5/1051; A61G5/1054; A61G5/12; A61G5/125; A61G5/128; B; B60; B60K; B60K1/00; B62; B62D; B62D5/00; B62D51/00; B62D51/005; A61G2203/00; A61G2203/10; A61G2203/14; Y; Y10; Y10S; Y10S180/00; Y10S180/907
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
163 words
A self-propelled wheelchair comprising a frame, a pair of nonsteerable main wheels supporting said frame and disposed at opposite sides thereof, a drive unit swingably interconnected with said frame, said drive unit including a drive motor and a pair of driving wheels, said main wheels comprising the front wheels of the wheelchair, said driving wheels comprising the back wheels of the wheelchair, driving transmission drivingly connecting said drive motor and said driving wheels, said driving transmission being self-braking when said driving motor is not operating, said drive unit also including a steering motor, a steering transmission operatively connecting said steering motor and said unit for swinging said unit and said drive motor and said steering motor relative to said frame, said steering transmission being self-braking when said steering motor is not operating, said drive motor including a drive shaft extending substantially parallel with an associated supporting surface, said drive unit being swingable about an axis extending substantially perpendicularly to said associated supporting surface.
Claim 2
Dependent Claim
163 words
A self-propelled wheelchair comprising a frame, a pair of nonsteerable main wheels supporting said frame and disposed at opposite sides thereof, a drive unit swingably interconnected with said frame, said drive unit including a drive motor and a pair of driving wheels, said main wheels comprising the front wheels of the wheelchair, said driving wheels comprising the back wheels of the wheelchair, driving transmission drivingly connecting said drive motor and said driving wheels, said driving transmission being self-braking when said driving motor is not operating, said drive unit also including a steering motor, a steering transmission operatively connecting said steering motor and said unit for swinging said unit and said drive motor and said steering motor relative to said frame, said steering transmission being self-braking when said steering motor is not operating, said drive motor including a drive shaft extending substantially parallel with an associated supporting surface, said drive unit being swingable about an axis extending substantially perpendicularly to said associated supporting surface.
Claim 3
Dependent Claim
16 words
Apparatus as defined in claim 1 wherein said driving transmission includes worm gearing and a differential.
Claim 4
Dependent Claim
38 words
Apparatus as defined in claim 1 wherein said steering transmission includes a worm wheel fixed with respect to said frame, and a worm screw engaging said worm wheel, said worm screw being operatively connected with said steering motor.
Claim 5
Dependent Claim
71 words
Apparatus as defined in claim 1 wherein said driving transmission includes a worm screw drivingly connected with said driving motor, a worm wheel engageable with said worm screw, said worm wheel being drivingly connected with said driving wheels, said steering transmission including a worm wheel fixed with respect to said frame, a worm screw engageable with said last-mentioned worm wheel, said last-mentioned worm screw being operatively connected with said steering motor.
Claim 6
Dependent Claim
106 words
Apparatus as defined in claim 1 including a source of electrical current for said steering motor, means connecting said source of current with said steering motor and including a resetting servodevice comprising two potentiometer including a master potentiometer and a slave potentiometer arranged in a bridge circuit, said slave potentiometer having a slave contact the position of which corresponds to the relative position between said drive unit and the frame, said master potentiometer having a contact for producing a potential difference across the bridge which will cause the resetting servodevice to turn the swingable drive unit in a direction so as to eliminate said potential difference.
Claim 7
Dependent Claim
27 words
Apparatus as defined in claim 2 wherein said slave potentiometer has a higher resistance per degree of turning movement in its central portion than its end portions.
Claim 8
Dependent Claim
28 words
Apparatus as defined in claim 2 wherein said master potentiometer has a lower resistance per degree of turning movement in its central portion than in its end portions.
Claim 9
Dependent Claim
40 words
Apparatus as defined in claim 2 wherein a small electrical cUrrent through said bridge circuit results in a low-speed operation of the steering motor, and a large current through the bridge circuit results in high-speed operation of the steering motor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |