US4098521A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wheelchair adaptable for passage in narrow spaces
Assignee: NATIONAL PATENT SEARCH ASSOC Inc
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Filing: 1976-08-09
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Granted: 1978-07-04
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Expires: 1996-08-09
Abstract
Abstract A wheelchair that may be used by disabled persons as a normal self-propelled vehicle and is easily convertible to a narrow attendant-propelled wheelchair for negotiating narrow passages such as airplane aisles and bathroom doors in places not equipped for the accommodation of the disabled. Wheels secondary to the main drive wheels are mounted within the limits of the frame perimeter and are not in ground contact when the main drive wheels are in use. Upon tilting the wheelchair, the secondary wheels contact the ground raising the primary wheels and enabling their rapid removal, the resulting chair being narrowed substantially to the width of the occupant. Steerable castor wheels are mounted inboard of the frame members allowing turns in tight places, and shortened or removable arms are provided for ease of lateral movement from or to the chair. Secondary footrests and drive linkage for secondary wheels are also provided.
Inventors
- 👤 Andrew Marvin Ferguson
- 👤 Ernest Voshell Keith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:54
CPC Classifications
A; A61; A61G; A61G5/00; A61G5/02; A61G5/021; A61G5/023; A61G5/024; A61G5/025; A61G5/10; A61G5/1083; A61G5/12; A61G5/125; A61G5/128; A61G2220/00; A61G2220/10; Y; Y10; Y10S; Y10S297/00; Y10S297/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
234 words
A wheelchair convertible to a narrow mode while the occupant is seated therein, comprising: a frame; wheel means mounted on said frame near the front portion thereof; main drive wheels removable mounted on said frame near the rear portion thereof, quick disconnect means on said drive wheels and said frame to enable said drive wheels to be mounted on and removed from said frame by the occupant while seated in the wheelchair in a lateral direction substantially parallel to the axis of rotation of said drive wheels; and secondary wheels mounted on said frame near the rear portion thereof and disposed rearwardly of the axis of said main drive wheels, said secondary wheels and said wheel means being disposed laterally inwardly of said main drive wheels, said secondary wheels being positioned to be out of engagement with the support surface for the wheelchair when it is supported by said wheel means and said main drive wheels, and said secondary wheels being positioned to be engagable with said support surface upon predetermined rearward tilting movement of said wheelchair to lift said main drive wheels out of contact with said support surface to enable said main drive wheels to be quickly laterally removed from said frame by the occupant while seated in the tilted wheelchair and to enable said wheelchair to be supported thereafter by said secondary wheels and said wheel means in a narrow mode.
Claim 2
Dependent Claim
234 words
A wheelchair convertible to a narrow mode while the occupant is seated therein, comprising: a frame; wheel means mounted on said frame near the front portion thereof; main drive wheels removable mounted on said frame near the rear portion thereof, quick disconnect means on said drive wheels and said frame to enable said drive wheels to be mounted on and removed from said frame by the occupant while seated in the wheelchair in a lateral direction substantially parallel to the axis of rotation of said drive wheels; and secondary wheels mounted on said frame near the rear portion thereof and disposed rearwardly of the axis of said main drive wheels, said secondary wheels and said wheel means being disposed laterally inwardly of said main drive wheels, said secondary wheels being positioned to be out of engagement with the support surface for the wheelchair when it is supported by said wheel means and said main drive wheels, and said secondary wheels being positioned to be engagable with said support surface upon predetermined rearward tilting movement of said wheelchair to lift said main drive wheels out of contact with said support surface to enable said main drive wheels to be quickly laterally removed from said frame by the occupant while seated in the tilted wheelchair and to enable said wheelchair to be supported thereafter by said secondary wheels and said wheel means in a narrow mode.
Claim 3
Dependent Claim
16 words
The wheelchair of claim 1 wherein said wheel means comprise a plurality of steerable castor wheels.
Claim 4
Dependent Claim
23 words
The wheelchair of claim 1 wherein said wheel means and said secondary wheels are disposed at least partially laterally inwardly of said frame.
Claim 5
Dependent Claim
12 words
The wheelchair of claim 1 wherein said secondary wheels are nonsteerable wheels.
Claim 6
Dependent Claim
15 words
The wheelchair of claim 1 further comprising manually actuatable drive means for said secondary wheels.
Claim 7
Dependent Claim
17 words
The wheelchair of claim 1 further comprising footrests removably mounted on the front portion of said frame.
Claim 8
Dependent Claim
25 words
The wheelchair of claim 1 wherein the width of said frame is substantially the same as the width of the seat portion of the wheelchair.
Claim 9
Dependent Claim
30 words
The wheelchair of claim 1 further comprising short armrests for providing support for the elbows of the occupant and facilitating movement of the occupant into and out of the wheelchair.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-03 | 1982-01-02 | 1982-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-03 | 1986-01-02 | 1986-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-03 | 1990-01-02 | 1990-07-04 | $7700.00 | Window Closed / Lapsed |