US3879718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Smoke detection unit with dual purpose alarm circuit
Assignee: Individual
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Filing: 1973-05-17
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Granted: 1975-04-22
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Expires: 1993-05-17
Abstract
Abstract A unit for detecting the presence of smoke in the air utilizing a single sound emitting device for producing a plurality of distinguishable sounds for indicating different conditions such as the presence of smoke and burnout of the actuating light source. The sound emitting device operates continuously to indicate a selected smoke threshhold point and operates intermittently to indicate burnout of the light source.
Inventors
- 👤 Gordon A Roberts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:16
CPC Classifications
G; G08; G08B; G08B17/00; G08B17/10; G08B17/103; G08B17/107; G08B17/11; G08B17/113
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
133 words
In a unit for detecting and signaling the existence of smoke in room air above a predetermined level, a casing having a smoke detection chamber therein, a light source in said casing operable to provide for light in said chamber, an alarm circuit utilizing a single sound emitting device for producing distinguishable sounds for indicating different conditions which it is desired to detect, namely, an alarm condition indicating the existence of room air smoke above a certain level and a trouble condition indicating burnout of said light source, said circuit including first circuit means operable to actuate said device to produce a first continuous sound indicating said alarm condition, and second circuit means operable to actuate said device to produce an intermittent sound distinguishable from said first sound and indicating said trouble condition.
Claim 2
Dependent Claim
133 words
In a unit for detecting and signaling the existence of smoke in room air above a predetermined level, a casing having a smoke detection chamber therein, a light source in said casing operable to provide for light in said chamber, an alarm circuit utilizing a single sound emitting device for producing distinguishable sounds for indicating different conditions which it is desired to detect, namely, an alarm condition indicating the existence of room air smoke above a certain level and a trouble condition indicating burnout of said light source, said circuit including first circuit means operable to actuate said device to produce a first continuous sound indicating said alarm condition, and second circuit means operable to actuate said device to produce an intermittent sound distinguishable from said first sound and indicating said trouble condition.
Claim 3
Dependent Claim
133 words
In a unit for detecting and signaling the existence of smoke in room air above a predetermined level, a casing having a smoke detection chamber therein, a light source in said casing operable to provide for light in said chamber, an alarm circuit utilizing a single sound emitting device for producing distinguishable sounds for indicating different conditions which it is desired to detect, namely, an alarm condition indicating the existence of room air smoke above a certain level and a trouble condition indicating burnout of said light source, said circuit including first circuit means operable to actuate said device to produce a first continuous sound indicating said alarm condition, and second circuit means operable to actuate said device to produce an intermittent sound distinguishable from said first sound and indicating said trouble condition.
Claim 4
Dependent Claim
133 words
In a unit for detecting and signaling the existence of smoke in room air above a predetermined level, a casing having a smoke detection chamber therein, a light source in said casing operable to provide for light in said chamber, an alarm circuit utilizing a single sound emitting device for producing distinguishable sounds for indicating different conditions which it is desired to detect, namely, an alarm condition indicating the existence of room air smoke above a certain level and a trouble condition indicating burnout of said light source, said circuit including first circuit means operable to actuate said device to produce a first continuous sound indicating said alarm condition, and second circuit means operable to actuate said device to produce an intermittent sound distinguishable from said first sound and indicating said trouble condition.
Claim 5
Dependent Claim
48 words
An alarm circuit according to claim 1 wherein said sound emitting device is an electrically driven horn and wherein said second circuit means includes oscillator means connected to said horn and operable in response to energizing of said oscillator means to provide for intermittent operation of said horn.
Claim 6
Dependent Claim
52 words
An alarm circuit according to claim 2 wherein said oscillator means includes a neon bulb and capacitor means, and circuit means connecting said bulb and said capacitor means and providing for flow of current pulses through said bulb when the voltage at said capacitor means exceeds the breakdown voltage of said bulb.
Claim 7
Dependent Claim
93 words
In a unit for detecting and signaling the existence of smoke in room air above a predetermined level, a casing having a smoke detection chamber therein, a light source in said casing operable to provide for light in said chamber, an alarm circuit including means for detecting burnout of said light source, said means comprising electrically energizable signal means, and circuit means connecting said light source and said signal means and operable in response to a voltage increase therein caused by light source burnout to provide for intermittent actuation of said signal means.
Claim 8
Dependent Claim
93 words
In a unit for detecting and signaling the existence of smoke in room air above a predetermined level, a casing having a smoke detection chamber therein, a light source in said casing operable to provide for light in said chamber, an alarm circuit including means for detecting burnout of said light source, said means comprising electrically energizable signal means, and circuit means connecting said light source and said signal means and operable in response to a voltage increase therein caused by light source burnout to provide for intermittent actuation of said signal means.
Claim 9
Dependent Claim
115 words
A circuit according to claim 4 wherein said circuit means includes voltage breakdown means normally providing high impedance path and operable to provide low impedance path in response to a selected threshhold potential connected thereacross, circuit means providing a current path through said voltage breakdown means to said signal means, capacitor means connected to said light source and to said voltage breakdown means and operable to intermittently provide for a voltage therethrough exceeding the breakdown voltage thereof in response to a voltage rise across said capacitor caused by burnout of said light source, said voltage breakdown means being operable when the breakdown voltage thereof is exceeded to pass an actuating pulse to said signal 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) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |