US4170005A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switch operated alarm circuit
Assignee: Individual
•
Filing: 1977-12-19
•
Granted: 1979-10-02
•
Expires: 1997-12-19
Abstract
Abstract A burglar alarm that has a series of switches located close to each other and that are responsive to the application of a magnetic field. One of the switches terminates current flow to a sentinel current device while the others initiate current flow to the sentinel current device. The sentinel current device operates to supply voltage for an alarm circuit when it conducts only. Thus, in order to render the device ineffective, one must know how to apply a magnetic field to the terminating switch only without activating any of the switches that initiate current flow. The switches are all located close together so that special knowledge is required to cut off supply voltage to the alarm circuit.
Inventors
- 👤 Norman G. Duke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:17
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/08; H; H01; H01H; H01H36/00; H01H36/0006; H01H36/0046
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
133 words
In an alarm circuit a sentinel device adapted to provide stand-by voltage to operate an alarm; said sentinel device being normally inoperative when an operating voltage is applied thereto; enabling means including a plurality of switches operable by the application of an energy field to render said sentinel device operative whereby to provide stand-by voltage for an alarm; first switch means operable by application of an energy field for rendering said sentinel device inoperative; second switch means operable on the opening of a door or the like to cause stand-by voltage of said sentinel device to operate said alarm when said sentinel device is rendered operative by said switches of said enabling means; said first switch means and said plurality of switches of said enabling means being in close proximity to each other.
Claim 2
Dependent Claim
133 words
In an alarm circuit a sentinel device adapted to provide stand-by voltage to operate an alarm; said sentinel device being normally inoperative when an operating voltage is applied thereto; enabling means including a plurality of switches operable by the application of an energy field to render said sentinel device operative whereby to provide stand-by voltage for an alarm; first switch means operable by application of an energy field for rendering said sentinel device inoperative; second switch means operable on the opening of a door or the like to cause stand-by voltage of said sentinel device to operate said alarm when said sentinel device is rendered operative by said switches of said enabling means; said first switch means and said plurality of switches of said enabling means being in close proximity to each other.
Claim 3
Dependent Claim
26 words
In an alarm circuit the elements claimed in claim 1 wherein said first switch means is surrounded by said plurality of switches of said enabling means.
Claim 4
Dependent Claim
18 words
In an alarm circuit the elements claimed in claim 2 wherein said energy field is a magnetic field.
Claim 5
Dependent Claim
26 words
An alarm adapted to sense as claimed in claim 3 in which said switches of said enabling means and said first switch means comprise reed switches.
Claim 6
Dependent Claim
26 words
An alarm adapted to sense as claimed in claim 3 in which said switch of said enabling means and said first switch means comprise reed switches.
Claim 7
Dependent Claim
26 words
An alarm adapted to sense as claimed in claim 2 in which said switches of said enabling means and said first switch means comprise reed switches.
Claim 8
Dependent Claim
18 words
In an alarm circuit the elements claimed in claim 1 wherein said energy field is a magnetic field.
Claim 9
Dependent Claim
26 words
An alarm adapted to sense as claimed in claim 7 in which said switches of said enabling means and said first switch means comprise reed switches.
Claim 10
Dependent Claim
26 words
An alarm adapted to sense as claimed in claim 1 in which said switches of said enabling means and said first switch means comprise reed switches.
References Cited (Backward Citations)
US2877361A
Cited
US2912540A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-10-01 | 1983-04-02 | 1983-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-01 | 1987-04-02 | 1987-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-01 | 1991-04-02 | 1991-10-02 | $7700.00 | Window Closed / Lapsed |