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US4223931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Doorknob attachment
Assignee: Schlage Lock Co LLC
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Filing: 1979-06-25
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Granted: 1980-09-23
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Expires: 1999-06-25
Abstract
Abstract The invention provides a simple, inexpensive, efficient means of converting a standard doorknob into a lever operated doorknob which may be easily operated by the handicapped. The invention allows the use of existing hardware trim and can be retro-fitted to existing installations.
Inventors
- 👤 Ralph E. Neary
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:52
CPC Classifications
E; E05; E05B; E05B1/00; E05B1/0053; Y; Y10; Y10S; Y10S16/00; Y10S16/30; Y10S292/00; Y10S292/02; Y10T; Y10T292/00; Y10T292/82
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
123 words
An operating lever for a conventional doorknob comprising: a mounting portion for mounting said operating lever to a doorknob; a lever secured to said mounting portion; said mounting portion being substantially secured by screw means to the back face of a conventional doorknob so as not to mar the estetic design of the doorknob; said mounting portion surrounding the stem of the doorknob for added support; said lever projecting forwardly from the plane of the door in a direction from the mounting portion of said doorknob lever; and said lever portion is provided with a convex curved surface facing said doorknob and in close proximity to said doorknob to minimize the possibility of a pinch point between said operating lever and said doorknob.
Claim 2
Dependent Claim
123 words
An operating lever for a conventional doorknob comprising: a mounting portion for mounting said operating lever to a doorknob; a lever secured to said mounting portion; said mounting portion being substantially secured by screw means to the back face of a conventional doorknob so as not to mar the estetic design of the doorknob; said mounting portion surrounding the stem of the doorknob for added support; said lever projecting forwardly from the plane of the door in a direction from the mounting portion of said doorknob lever; and said lever portion is provided with a convex curved surface facing said doorknob and in close proximity to said doorknob to minimize the possibility of a pinch point between said operating lever and said doorknob.
Claim 3
Dependent Claim
21 words
The doorknob operating lever of claim 1 wherein: said lever portion is provided with a hollowed out portion to improve grip.
Claim 4
Dependent Claim
19 words
The doorknob operating lever of claim 1 wherein: said lever and mounting portion are manufactured from a semi-rigid material.
Claim 5
Dependent Claim
22 words
The doorknob operating lever of claim 1 wherein: said doorknob operating lever is manufactured from a plastic material, such as vinyl plastic.
Claim 6
Dependent Claim
27 words
The doorknob operating lever of claim 1 wherein: said mounting portion is split to minimize the possibility of said mounting portion being utilized as a pry point.
Claim 7
Dependent Claim
24 words
The doorknob operating lever of claim 1 wherein: said lever portion is manufactured from a low melting point material as a fire safety measure.
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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) | 1983-09-23 | 1984-03-24 | 1984-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-23 | 1988-03-24 | 1988-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-23 | 1992-03-24 | 1992-09-23 | $7700.00 | Window Closed / Lapsed |