US3569645A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tamperproof switch devices for burglar alarm systems, affording cordless connections across protected station separations
Assignee: Individual
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Filing: 1968-10-29
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Granted: 1971-03-09
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Expires: 1988-10-29
Abstract
Abstract The fundamental switch unit interposed in a conductor included in the circuit, comprises a permanent magnet carried for example on a door, and an armature carried on a door frame, so when the door is closed, the magnet attracts the armature thereto into contact therewith, thus providing a current path through said conductor. Said switch components are relatively movable from a normal rest position, independent of door movement. Use of two switch units eliminates need of a door cord. Use of four units can serve to break the lead-in and the leadout wires at the protected opening. With a small addition, a unit can include a normally closed switch, which assembly can serve in protective circuits which are either or a combination of open and closed circuit systems.
Inventors
- 👤 Lawrence N Lea
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:06
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/08; H; H01; H01H; H01H3/00; H01H3/02; H01H3/16; H01H3/161; H01H36/00
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
224 words
In a switch device comprising two switch units interposed in a conductor means included in the circuit of a burglar alarm system protecting a frame member having a movable closure member, said device consisting of a permanent magnet element for each switch unit respectively, mounted on the closure member and insulated therefrom, a dielectric casing mounted on the frame member, an armature element for each magnet element respectively, positioned recessed within the casing, at a rest position therein from which it is movable, and spring means within the casing, biasing each armature element to its rest position; said casing being open so said armature elements are movable outwardly to protrude from the casing whereupon said spring means are stressed; said elements being electrically conductive ; said conductor means being in two parts which are entirely off the closure member and connected respectively to the armature elements; the magnet elements being connected by a conductor positioned entirely on the closure member; each magnet element facing its related armature element when the closure member is in closing position, whereupon the attraction between each magnet element and its related armature element will cause each armature element to come out of said casing and into contact with its related magnet element thereby forming a current path connecting said parts of the conductor means whereby current can flow therethrough.
Claim 2
Dependent Claim
224 words
In a switch device comprising two switch units interposed in a conductor means included in the circuit of a burglar alarm system protecting a frame member having a movable closure member, said device consisting of a permanent magnet element for each switch unit respectively, mounted on the closure member and insulated therefrom, a dielectric casing mounted on the frame member, an armature element for each magnet element respectively, positioned recessed within the casing, at a rest position therein from which it is movable, and spring means within the casing, biasing each armature element to its rest position; said casing being open so said armature elements are movable outwardly to protrude from the casing whereupon said spring means are stressed; said elements being electrically conductive ; said conductor means being in two parts which are entirely off the closure member and connected respectively to the armature elements; the magnet elements being connected by a conductor positioned entirely on the closure member; each magnet element facing its related armature element when the closure member is in closing position, whereupon the attraction between each magnet element and its related armature element will cause each armature element to come out of said casing and into contact with its related magnet element thereby forming a current path connecting said parts of the conductor means whereby current can flow therethrough.
Claim 3
Dependent Claim
73 words
A switch device as defined in claim 1, including a conductive piece mounted in said casing, a conductive arm extending from one of said armature elements and contacting said conductive piece whereupon movement of said one armature element when the closing member is in closing position, said arm will be moved away from said conductive piece, and binding posts conductively connected with said conductive piece, said armature elements and said magnet elements respectively.
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) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |