Patent US3794989A successfully refreshed from Google Patents.
US3794989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Appliance theft alarm system
Assignee: Individual
•
Filing: 1972-04-07
•
Granted: 1974-02-26
•
Expires: 1992-04-07
Abstract
Abstract Alarm system for indicating unauthorized disconnection of an appliance such as a TV receiver or the like. The alarm system includes an indication device, such as a lamp, connected in series with a signal apparatus to receive a source of operating power. A shunt circuit including the appliance circuit or other circuit being monitored is connected to bypass the signal apparatus, so that current normally flows through the indication device and the shunt circuit to operate the indication device when the monitored circuit is uninterrupted. Opening of the monitored circuit, such as by unauthorized disconnection of a TV receiver, opens the shunt circuit and permits current to flow through the signal apparatus, initiating an appropriate alarm or other signal. The current flowing through the series circuit may be less than the amount necessary to produce the indication normally present while the monitored circuit is uninterrupted.
Inventors
- 👤 W Manley
- 👤 E Manley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:38
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/14; G08B13/1409
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
282 words
Apparatus for detecting unauthorized interruption of an established electric circuit, comprising: first means for providing an indication that the established circuit is uninterrupted in response to the passage of a predetermined electric current through said first means; second means operative to establish a signal condition in response to current flow therethrough; said first means and second means being connected in series circuit for connection to a source of operating voltage; third means establishing a circuit in shunt around said second means and including the unauthorized interruption circuit so that current flowing through said first means and said third means causes said indication of uninterruption by said first means while the unauthorized interruption circuit is uninterrupted and so that current flow through said second means upon interruption of the shunt circuit established by said third means causes said second means to establish said signal condition; said first means having a first impedance and requiring at least a first amount of current to provide said indication; said second means having a second impedance and requiring at least a second amount of current to establish said signal condition, said second amount of current being less than said first amount of current; said first impedance allowing at least said first amount of current to flow in the series circuit including said first means and said third means, in response to the operating voltage, when said shunt circuit is uninterrupted; and said second impedance, upon interruption of said shunt circuit, allowing current flow in the series circuit including said first means and said second means in an amount which is less than said first amount of current and which is at least said second amount of current.
Claim 2
Dependent Claim
282 words
Apparatus for detecting unauthorized interruption of an established electric circuit, comprising: first means for providing an indication that the established circuit is uninterrupted in response to the passage of a predetermined electric current through said first means; second means operative to establish a signal condition in response to current flow therethrough; said first means and second means being connected in series circuit for connection to a source of operating voltage; third means establishing a circuit in shunt around said second means and including the unauthorized interruption circuit so that current flowing through said first means and said third means causes said indication of uninterruption by said first means while the unauthorized interruption circuit is uninterrupted and so that current flow through said second means upon interruption of the shunt circuit established by said third means causes said second means to establish said signal condition; said first means having a first impedance and requiring at least a first amount of current to provide said indication; said second means having a second impedance and requiring at least a second amount of current to establish said signal condition, said second amount of current being less than said first amount of current; said first impedance allowing at least said first amount of current to flow in the series circuit including said first means and said third means, in response to the operating voltage, when said shunt circuit is uninterrupted; and said second impedance, upon interruption of said shunt circuit, allowing current flow in the series circuit including said first means and said second means in an amount which is less than said first amount of current and which is at least said second amount of current.
Claim 3
Dependent Claim
34 words
Apparatus as in claim 1, wherein: said first means comprises a source of illumination, so that current flow through said source of illumination and said third means provides said indication of an uninterrupted circuit.
Claim 4
Dependent Claim
88 words
Apparatus as in claim 1, in which said electric circuit includes disconnectable circuit elements wherein: said third means includes a first circuit extending from the circuit interconnection between said first and second means to a first disconnectable circuit element of the electric circuit; said third means includes a second circuit extending from a second disconnectable circuit element of the electric circuit to establish said shunt around said second means; and said unauthorized interruption circuit includes a selectively disconnectable circuit connection between said first and second disconnectable circuit elements.
Claim 5
Dependent Claim
76 words
Apparatus as in claim 1, further comprising: condition responsive means disposed in series circuit with said shunt circuit; said condition responsive means operative in the absence of a certain condition to assume a closed-circuit state which maintains continuity in said shunt circuit and further operative in the presence of said certain condition to assume an open-circuit condition which disrupts such shunt circuit continuity to permit current flow through said second means for establishing said circuit condition.
Claim 6
Dependent Claim
247 words
Apparatus for detecting unauthorized interruption of one or more of plural established electric circuits, comprising: a plurality oF indication circuits corresponding in number to the plurality of electric circuits, each of said indication circuits including means for providing an indication that an established circuit is uninterrupted in response to the passage of a predetermined electric current therethrough; second means operative to establish a signal condition in response to current flow therethrough; said plural indication circuits being connected in parallel circuit with each other and said parallel circuit being connected in series circuit with said second means to receive a source of operating voltage; each of said plural indication circuits including means operatively connected in series with the corresponding indicating means and operative to allow only unidirectional current flow in each indicating circuit; a plurality of separate control circuit means connected to establish a corresponding plurality of circuits in shunt around said second means and a corresponding one of said unidirectional current flow means, each of said plural control circuit means including a corresponding one of such established circuits, so that current flowing through one of said indication circuits and the corresponding one of said control circuit means causes said indication of uninterruption by said first means while the established circuit associated with said one control circuit is uninterrupted and so that the current flow through said second means upon interruption of the shunt circuit provided by such established circuit causes said second means to establish signal condition.
Claim 7
Dependent Claim
247 words
Apparatus for detecting unauthorized interruption of one or more of plural established electric circuits, comprising: a plurality oF indication circuits corresponding in number to the plurality of electric circuits, each of said indication circuits including means for providing an indication that an established circuit is uninterrupted in response to the passage of a predetermined electric current therethrough; second means operative to establish a signal condition in response to current flow therethrough; said plural indication circuits being connected in parallel circuit with each other and said parallel circuit being connected in series circuit with said second means to receive a source of operating voltage; each of said plural indication circuits including means operatively connected in series with the corresponding indicating means and operative to allow only unidirectional current flow in each indicating circuit; a plurality of separate control circuit means connected to establish a corresponding plurality of circuits in shunt around said second means and a corresponding one of said unidirectional current flow means, each of said plural control circuit means including a corresponding one of such established circuits, so that current flowing through one of said indication circuits and the corresponding one of said control circuit means causes said indication of uninterruption by said first means while the established circuit associated with said one control circuit is uninterrupted and so that the current flow through said second means upon interruption of the shunt circuit provided by such established circuit causes said second means to establish signal condition.
Claim 8
Dependent Claim
166 words
Apparatus as in claim 5, wherein: each of said indication means has a first impedance and requires at least a first amount of current to provide said indication; said second means has a second impedance and requires at least a second amount of current to establish said signal condition, said second amount of current being less than said first amount of current; said first impedance allows at least said first amount of current to flow in the series circuit including one of said indication circuits, a corresponding one of said unidirectional current flow means, and a corresponding one of said shunt circuits, in response to the operating voltage, when said corresponding shunt circuit is uninterrupted; and said second impedance, upon termination of any of said shunt circuits, allows current flow in the series circuit including one of said indication circuits and said second means in an amount which is less than said first amount of current and which is at least said second amount of current.
Claim 9
Dependent Claim
54 words
Apparatus as in claim 6, wherein: each of said indication means comprises a source of illumination so that current of at least said first amount flowing through said indication means and a corresponding one of said control circuit means provides said indication that the established circuit of said one control circuit means is uninterrupted.
Claim 10
Dependent Claim
75 words
Apparatus as in claim 6, wherein: said unidirectional current flow means in each indication circuit comprises a diode connected in series with the corresponding indicating means in polarity relation to permit current flow through the corresponding indicating means and said second means, when the shunt circuit associated with such indication circuit is interrupted, and to prevent current flow through the corresponding indicating means and an uninterrupted shunt circuit associated with another of said indication circuits.
Claim 11
Dependent Claim
66 words
Apparatus as in claim 6, further comprising: condition responsive means disposed in series circuit with at least one of said control circuit means; said condition responsive means operative in the absence of a predetermined condition to assume a closed-circuit state and further operative in the presence of said predetermined condition to assume an open-circuit condition which interrupts the shunt circuit established by said control circuit means.
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) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |