US3638813A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wheelchair lifting device
Assignee: Individual
•
Filing: 1969-11-25
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Granted: 1972-02-01
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Expires: 1989-11-25
Abstract
Abstract A chair lift having a mount, lifting arms supporting a chair platform, and horizontal swivel arms for rotating the chair platform about the mount, a power supply and electrical circuitry being provided for controlling hydraulic pressure in cylinders connected to move the lifting and swivel arms.
Inventors
- 👤 John H Strong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:07
CPC Classifications
B; B66; B66B; B66B9/00; A; A61; A61G; A61G3/00; A61G3/02; A61G3/06; A61G3/063; Y; Y10; Y10S; Y10S414/00; Y10S414/13; Y10S414/134
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
205 words
A wheelchair lifting device, comprising: a mount; first means pivotally connected to said mount for swinging thereabout; a wheelchair platform; second means pivotally connected to said first means and partially connected to said wheelchair platform for lifting and tilting said wheelchair platform, the tilt being about a horizontal axis; a power source connected to said amount for activating said first means and said second means in the alternative; a control circuit for actuating said power source; said second means comprising a lower arm pivotally connected between said first means and said wheelchair platform; an upper arm pivotally connected between said first means and said wheelchair platform and having a vertical slot at the end adjacent said wheelchair platform; and a hydraulic cylinder pivotally connected to said first means at one end thereof and having a ram at the other end thereof pivotally connected to said upper arm, said ram, upon being activated by said power source, extending upward from and moving downward into said hydraulic valve, in the alternative, rotating said upper arm and said lower arm in a clockwise and a counterclockwise direction, in the alternative, about their respective pivot points located at said first means for respectively raising and lowering said wheelchair platform.
Claim 2
Dependent Claim
205 words
A wheelchair lifting device, comprising: a mount; first means pivotally connected to said mount for swinging thereabout; a wheelchair platform; second means pivotally connected to said first means and partially connected to said wheelchair platform for lifting and tilting said wheelchair platform, the tilt being about a horizontal axis; a power source connected to said amount for activating said first means and said second means in the alternative; a control circuit for actuating said power source; said second means comprising a lower arm pivotally connected between said first means and said wheelchair platform; an upper arm pivotally connected between said first means and said wheelchair platform and having a vertical slot at the end adjacent said wheelchair platform; and a hydraulic cylinder pivotally connected to said first means at one end thereof and having a ram at the other end thereof pivotally connected to said upper arm, said ram, upon being activated by said power source, extending upward from and moving downward into said hydraulic valve, in the alternative, rotating said upper arm and said lower arm in a clockwise and a counterclockwise direction, in the alternative, about their respective pivot points located at said first means for respectively raising and lowering said wheelchair platform.
Claim 3
Dependent Claim
132 words
The wheelchair lifting device of claim 1 comprising a horizontal member extending from said wheelchair platform and protruding through the slot of said upper arm, said upper arm being pivotally attached to said wheelchair platform in a friction fit so that said horizontal member does not fall down to the bottom of the slot of said upper arm from the weight of said wheelchair platform, and a link stop adjacent said lower arm for terminating its upper clockwise movement at a predetermined height, said upper arm continuing clockwise movement after the termination of the clockwise movement of said lower arm causing said horizontal member to slide down to the bottom of the vertical slot of said upper arm allowing said wheelchair platform to pivot about its pivot point adjacent said lower arm.
Claim 4
Dependent Claim
181 words
A wheelchair lifting device, comprising: a mount; first means pivotally connected to said mount for swinging thereabout; a wheelchair platform; second means pivotally connected to said first means and partially connected to said wheelchair platform for lifting and tilting said wheelchair platform, the tilt being about a horizontal axis; a power source connected to said mount for activating said first means and said second means in the alternative; a control circuit for actuating said power source; said control circuit comprising first switch means; a control solenoid; a hydraulic valve connected between said control solenoid and said first means; delay means; said power source including a pump and a reservoir; and pressure lines connected between said reservoir and said hydraulic valve and between said hydraulic valve and said first means, said first switch means connected in series with said control solenoid to open said hydraulic valve and also connected in series with said delay means and the pump of said power source for pumping oil pressure through said pressure line by means of the opened hydraulic valve to activate said first means.
Claim 5
Dependent Claim
181 words
A wheelchair lifting device, comprising: a mount; first means pivotally connected to said mount for swinging thereabout; a wheelchair platform; second means pivotally connected to said first means and partially connected to said wheelchair platform for lifting and tilting said wheelchair platform, the tilt being about a horizontal axis; a power source connected to said mount for activating said first means and said second means in the alternative; a control circuit for actuating said power source; said control circuit comprising first switch means; a control solenoid; a hydraulic valve connected between said control solenoid and said first means; delay means; said power source including a pump and a reservoir; and pressure lines connected between said reservoir and said hydraulic valve and between said hydraulic valve and said first means, said first switch means connected in series with said control solenoid to open said hydraulic valve and also connected in series with said delay means and the pump of said power source for pumping oil pressure through said pressure line by means of the opened hydraulic valve to activate said first means.
Claim 6
Dependent Claim
74 words
The wheelchair device of claim 3, comprising second switch means connected between said first switch means and a door through which the wheelchair is to be moved, said second switch means connected to a door and closing circuit when the door is in the open position, and third switch means connected in series between said second switch means and said first switch means and closing circuit only after said second means has been activated.
Claim 7
Dependent Claim
34 words
The wheelchair device of claim 4, wherein said delay means comprises a plurality of relays and a vacuum tube connected in series between said first switch means and the pump of said power source.
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) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |