Patent US686536A successfully refreshed from Google Patents.
US4285221A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Retrofit doorknob lock apparatus
Assignee: Individual
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Filing: 1979-06-18
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Granted: 1981-08-25
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Expires: 1999-06-18
Abstract
Abstract Apparatus for securing a doorknob against unauthorized entry. A shroud fits over the entire doorknob and its associated shaft, and extends to fit on or over the rose through which the shaft extends. A clevis fits through slots in the shroud to retain the shroud in place on the door knob and shaft. The present apparatus can be used to retrofit a lock onto an existing knob which has no locking structure, and also prevents tampering or unauthorized access to an existing built-in lock cylinder of a doorknob.
Inventors
- 👤 Maxwell G. Atchisson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:47
CPC Classifications
E; E05; E05B; E05B13/00; E05B13/001; Y; Y10; Y10T; Y10T70/00; Y10T70/50; Y10T70/5611; Y10T70/5854; Y10T70/5867; Y10T70/70; Y10T70/7441; Y10T70/7915; Y10T70/7955; Y10T70/796; Y10T70/7977; Y10T70/7983; Y10T70/80; Y10T70/8838
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
116 words
Retrofit lock apparatus for a door knob, comprising: means operative to fit over and entirely enclose a knob and associated shaft of a doorknob, so as to shroud the knob and shaft from unauthorized access; and means selectably operative to retain said enclosing means in place shrouding the knob and shaft; said enclosing means comprising an enclosure having an open end to receive the knob and to permit said enclosure to fit over the knob and associated shaft; said enclosure having a plurality of openings located at different spacings from said open end; and said retaining means extending within a selected one of said openings to maintain said enclosure in place shrouding the knob and shaft.
Claim 2
Dependent Claim
116 words
Retrofit lock apparatus for a door knob, comprising: means operative to fit over and entirely enclose a knob and associated shaft of a doorknob, so as to shroud the knob and shaft from unauthorized access; and means selectably operative to retain said enclosing means in place shrouding the knob and shaft; said enclosing means comprising an enclosure having an open end to receive the knob and to permit said enclosure to fit over the knob and associated shaft; said enclosure having a plurality of openings located at different spacings from said open end; and said retaining means extending within a selected one of said openings to maintain said enclosure in place shrouding the knob and shaft.
Claim 3
Dependent Claim
90 words
Apparatus as in claim 1, wherein: said openings in said enclosure at each selected spacing from said open end comprise a set of openings, and each set of openings includes at least a pair of openings which are disposed alongside the shaft associated with the knob when said enclosure is in place shrouding the knob and shaft; and said retaining means selectably extends with in each opening of a selected set of openings, so as to engage the knob and prevent removal of said enclosure from the knob and shaft.
Claim 4
Dependent Claim
28 words
Apparatus as in claim 2, wherein: each said set of openings comprises a slot formed in each side of said enclosure a selected spacing from said open end.
Claim 5
Dependent Claim
66 words
Apparatus as in claim 3, wherein: said retaining means comprises a plate having a pair of arms joined together at one end and each having a free end; said free ends of said plate being extendable through a selected set of slots in said enclosure; and means associated with at least one of said free ends to selectably prevent removal of said plate from said ots.
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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) | 1984-08-24 | 1985-02-23 | 1985-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-24 | 1989-02-23 | 1989-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-24 | 1993-02-23 | 1993-08-25 | $7700.00 | Window Closed / Lapsed |