US4040381A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Visual burglar alarm
Assignee: Individual
•
Filing: 1976-04-02
•
Granted: 1977-08-09
•
Expires: 1996-04-02
Abstract
Abstract A visual burglar alarm in the form of a mechanism for indicating that a door has been opened at least once during the absence of the occupant and therefore that caution should be exercised by the occupant in entering the room closed off by the door; the mechanism includes a tubular housing having a constriction narrowing a portion of the bore, means for attaching the tubular housing upright at the upper margin of a door, a magnet loosely held in the bore above the constriction, a non-magnetic shank extending down from the magnet and loosely passing through the constriction, and means for causing the magnet to adhere at the door jamb when thrust up from below by pressure on the lower end of the shank, so that when the door opens the magnet falls and gives indication of intrusion.
Inventors
- 👤 Gerard G. Keogh, Sr.
- 👤 Gerard G. Keogh, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:47
CPC Classifications
G; G08; G08B; G08B5/00; G08B13/00; G08B13/02; G08B13/08
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
151 words
A burglar alarm for installation on a doorway having relative opening and closing motion between first and second parts of the doorway, comprising: a housing for upright installation on a first part of a doorway, a magnet, said housing having a bore therein, means intermediate said housing for retaining the magnet within the housing, said means intermediate of the housing forming a constriction of said bore within said housing, means for lifting the magnet comprising a shank affixed to the magnet; means locatable on said second part of a doorway for causing the magnet when lifted to adhere magnetically adjacent said second part of a doorway, to fall within the housing on said relative opening motion between first and second parts of a doorway and to remain in the fallen position upon doorway reclosure; and means for affording visual indication of the position of the magnet with respect to the housing.
Claim 2
Dependent Claim
151 words
A burglar alarm for installation on a doorway having relative opening and closing motion between first and second parts of the doorway, comprising: a housing for upright installation on a first part of a doorway, a magnet, said housing having a bore therein, means intermediate said housing for retaining the magnet within the housing, said means intermediate of the housing forming a constriction of said bore within said housing, means for lifting the magnet comprising a shank affixed to the magnet; means locatable on said second part of a doorway for causing the magnet when lifted to adhere magnetically adjacent said second part of a doorway, to fall within the housing on said relative opening motion between first and second parts of a doorway and to remain in the fallen position upon doorway reclosure; and means for affording visual indication of the position of the magnet with respect to the housing.
Claim 3
Dependent Claim
37 words
A burglar alarm as recited in claim 1, the shank being of non-magnetic material and having a portion dimensioned for extending downward through the constriction and, in said fallen position, protruding for providing access to the shank.
Claim 4
Dependent Claim
32 words
A burglar alarm as recited in claim 2, the means for affording visual indication of the position of the magnet comprising at least a portion of the housing being of transparent material.
Claim 5
Dependent Claim
29 words
A burglar alarm as recited in claim 2, the means for affording visual indication of the position of the magnet comprising the housing being a length of transparent tubing.
Claim 6
Dependent Claim
25 words
A burglar alarm as recited in claim 2, the housing having an open top and bottom and having therein a tubular structure forming sad constriction.
Claim 7
Dependent Claim
21 words
A burglar alarm as recited in claim 5, and means for cushioning at said tubular structure the fall of the magnet.
Claim 8
Dependent Claim
50 words
A burglar alarm as recited in claim 2, the housing having a squared cross-sectional shape open at the top, and means on an exterior portion of the housing for affixing the housing to a first portion of a doorway with the open top adjacent said second portion of a doorway.
Claim 9
Dependent Claim
34 words
A burglar alarm as recited in claim 2, the housing having half-round cross-sectional shape providing a flat mounting surface, and means for affixing the flat mounting surface to a first portion of a doorway.
Claim 10
Dependent Claim
16 words
A burglar alarm as recited in claim 8, said means for affixing comprising a self-adhesive layer.
Claim 11
Dependent Claim
31 words
A burglar alarm as recited in claim 1, the means for causing the magnet to adhere magnetically comprising a ferrous member, and means for mounting the ferrous member above the housing.
Claim 12
Dependent Claim
21 words
A burglar alarm as recited in claim 10, the means for mounting the ferrous member comprising self-adhesive on a portion thereof.
Claim 13
Dependent Claim
32 words
A burglar alarm as recited in claim 10, the means for causing the magnet to adhere magnetically comprising a ferrous angle having first and second legs joined at substantially a right angle.
Claim 14
Dependent Claim
26 words
A burglar alarm as recited in claim 12, and means for mounting the ferrous angle, including self-adhesive on an exterior surface of one of said legs.
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) | 1980-08-08 | 1981-02-07 | 1981-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-08 | 1985-02-07 | 1985-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-08 | 1989-02-07 | 1989-08-09 | $7700.00 | Window Closed / Lapsed |