US4007956A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Doorknob guard
Assignee: Individual
•
Filing: 1975-05-23
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Granted: 1977-02-15
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Expires: 1995-05-23
Abstract
Abstract A device which protects the knob of a door lock to prevent the breaking thereof and entry includes an outer cylindrical member rotatably secured about the knob assembly by the rose of the knob assembly. An inner cylindrical member is secured about the knob assembly, and includes a plurality of axially extending grooves which engage cooperating ribs extending inwardly from the outer member. The inner member includes a hole in one end thereof to permit key access to the knob, and at least one annular friction ring disposed within the inner member for transmitting a limited magnitude of torque to the knob. The device protects the knob assembly by preventing tampering therewith and also preventing breaking the lock by applying high torque to the knob.
Inventors
- 👤 Steven K. Harris
- 👤 Stanley P. Schiffman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:26
CPC Classifications
E; E05; E05B; E05B13/00; E05B13/001; Y; Y10; Y10S; Y10S292/00; Y10S292/02; Y10T; Y10T292/00; Y10T292/82; Y10T292/91; Y10T70/00; Y10T70/70; Y10T70/7441; Y10T70/7915; Y10T70/7927; Y10T70/7949; Y10T74/00; Y10T74/20; Y10T74/20576; Y10T74/20732; Y10T74/20834; Y10T74/2084
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
83 words
A door knob protective device, comprising a first member secured about a door knob, said first member being formed of rigid, non-compressible material, and friction means disposed within said first member and about said door knob for transmitting a limited and unincreasable amount of torque therebetween, said friction means including a second member, within said first member, secured about said knob, and wherein said first and second members include at least one pair of cooperating torque and groove portions to transmit torque therebetween.
Claim 2
Dependent Claim
83 words
A door knob protective device, comprising a first member secured about a door knob, said first member being formed of rigid, non-compressible material, and friction means disposed within said first member and about said door knob for transmitting a limited and unincreasable amount of torque therebetween, said friction means including a second member, within said first member, secured about said knob, and wherein said first and second members include at least one pair of cooperating torque and groove portions to transmit torque therebetween.
Claim 3
Dependent Claim
38 words
The device of claim 1, wherein said tongue and groove portions are parallel to the axis of rotation of said knob, and said second member is freely positioned with respect to said first member in the axial direction.
Claim 4
Dependent Claim
36 words
The device of claim 1, wherein said second member comprises a hollow cylindrical member having a hole in each end thereof, said cylindrical member being formed of two longitudinal half cylinders joined along a longitudinal axis.
Claim 5
Dependent Claim
37 words
The device of claim 1, wherein said friction means comprises at least one friction member disposed within said second member and about said knob and impinging on said knob and the interior surface of said second member.
Claim 6
Dependent Claim
17 words
The device of claim 4, wherein said friction member comprises an annular ring secured about said knob.
Claim 7
Dependent Claim
50 words
The device of claim 1, wherein said first member comprises a hollow cylindrical member, and said first and second members are joined in a fixed rotational relationship each to the other, said friction means further including means for providing a limited torque engagement between said second member and said knob.
Claim 8
Dependent Claim
64 words
A door knob protective device, comprising a first member secured about a door knob, and friction means disposed between said first member and said door knob for transmitting a limited amount of torque therebetween, said first member comprising a hollow cylindrical member, and further including a retaining ring pivotally joined in said first member and secured to the surface from which said knob extends.
Claim 9
Dependent Claim
64 words
A door knob protective device, comprising a first member secured about a door knob, and friction means disposed between said first member and said door knob for transmitting a limited amount of torque therebetween, said first member comprising a hollow cylindrical member, and further including a retaining ring pivotally joined in said first member and secured to the surface from which said knob extends.
References Cited (Backward Citations)
US3306643A
Cited
US3428351A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-15 | 1980-08-16 | 1981-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-15 | 1984-08-16 | 1985-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-15 | 1988-08-16 | 1989-02-15 | $7700.00 | Window Closed / Lapsed |