US3889250A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active frequency-responsive glass breakage detector
Assignee: Gulf and Western Manufacturing Co
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Filing: 1973-10-15
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Granted: 1975-06-10
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Expires: 1993-10-15
Abstract
Abstract The detector is primarily for detecting glass breakage and is constructed as an active device or system for detecting the breakage and generating an alarm signal. The detector generally comprises a transmitter trandsucer of fixed first frequency below the frequency occasioned by breakage, a receiver transducer for receiving a signal which is a composite of the first frequency signal and the breakage frequency signal when a breakage occurs, a demodulator or mixer for obtaining the difference or sum frequency and alarm means for establishing an alarm condition upon detection of this difference or sum frequency.
Inventors
- 👤 Elias E Solomon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:22
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/04
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
113 words
A system for detecting breakage of a solid material, said system comprising; a transmitter transducer disposed at one area of said material for establishing a signal of first frequency, said material creating a signal of second frequency when broken, a receiver transducer disposed at another area of said material for receiving a control signal which is said first frequency signal when no breakage occurs and a composite of the first and second frequency signals when breakage occurs, means for mixing said control signal with said first frequency signal to provide at Least a third frequency signal when breakage occurs, and means for indicating an alarm condition upon detection of said third frequency signal.
Claim 2
Independent Claim
113 words
A system for detecting breakage of a solid material, said system comprising; a transmitter transducer disposed at one area of said material for establishing a signal of first frequency, said material creating a signal of second frequency when broken, a receiver transducer disposed at another area of said material for receiving a control signal which is said first frequency signal when no breakage occurs and a composite of the first and second frequency signals when breakage occurs, means for mixing said control signal with said first frequency signal to provide at Least a third frequency signal when breakage occurs, and means for indicating an alarm condition upon detection of said third frequency signal.
Claim 3
Dependent Claim
17 words
The system of claim 1 wherein said second frequency signal is on the order of 250K Hertz.
Claim 4
Dependent Claim
15 words
The system of claim 2 wherein said first frequency is less than said second frequency.
Claim 5
Dependent Claim
18 words
The system of claim 1 wherein said third frequency is the difference between said first and second frequencies.
Claim 6
Dependent Claim
17 words
The system of claim 1 comprising amplifier means coupled from said receiver transducer to said mixing means.
Claim 7
Dependent Claim
17 words
The system of claim 5 comprising a plurality of transmitter-receiver pairs and like number of amplifier means.
Claim 8
Dependent Claim
19 words
The system of claim 6 wherein said mixing means includes a demodulator for providing a difference third frequency signal.
Claim 9
Dependent Claim
32 words
The system of claim 7 comprising a high pass filter coupled intermediate said demodulator and alarm means for rejecting frequency signals below said third frequency signal and passing said third frequency signal.
Claim 10
Dependent Claim
38 words
The system of claim 1 including means coupled from said receiver transducer for supervising the presence of said first frequency signal and coupling an alarm signal to said alarm means upon the absence of said first frequency signal.
Claim 11
Dependent Claim
18 words
The system of claim 9 including a plurality of transmitter transducers and a like plurality of receiver transducers.
Claim 12
Dependent Claim
36 words
The system of claim 10 wherein said supervising means monitors all said receiver transducers and an alarm condition is established upon the absence of a signal of first frequency from any one of said receiver transducers.
Claim 13
Independent Claim
113 words
A system for detecting breakage of a solid material, said system comprising; a transmitter transducer disposed at one area of the material for establishing a signal of first frequency, said material creating a signal of second frequency when broken, a receiver transducer disposed at another area of the material for receiving a signal which is said first frequency signal when no breakage occurs and a composite of the first and second frequency signals when breakage occurs, means for detecting said control signal and generating an alarm signal upon detection of said second frequency signal when breakage occurs, and means coupled from said receiver transducer for supervising the presence of said first frequency signal.
Claim 14
Independent Claim
113 words
A system for detecting breakage of a solid material, said system comprising; a transmitter transducer disposed at one area of the material for establishing a signal of first frequency, said material creating a signal of second frequency when broken, a receiver transducer disposed at another area of the material for receiving a signal which is said first frequency signal when no breakage occurs and a composite of the first and second frequency signals when breakage occurs, means for detecting said control signal and generating an alarm signal upon detection of said second frequency signal when breakage occurs, and means coupled from said receiver transducer for supervising the presence of said first frequency signal.
Claim 15
Dependent Claim
35 words
The system of claim 12 wherein said means for supervising has an output coupled to said means for generating an alarm signal for generating an alarm signal upon the absence of said first frequency signal.
Claim 16
Dependent Claim
64 words
In a system having means for detecting breakage of a solid material including at least one transmitter transducer for establishing a first frequency signal and at least one receiver transducer, a supervisory system comprising means coupled from said receiver transducer for supervising the presence of said first frequency signal and means for generating an alarm signnal upon the absence of said first frequency signal.
Claim 17
Dependent Claim
64 words
In a system having means for detecting breakage of a solid material including at least one transmitter transducer for establishing a first frequency signal and at least one receiver transducer, a supervisory system comprising means coupled from said receiver transducer for supervising the presence of said first frequency signal and means for generating an alarm signnal upon the absence of said first frequency signal.
Claim 18
Dependent Claim
17 words
The system of claim 14 including a plurality of transmitter transducers and a plurality of receiver transducers.
Claim 19
Dependent Claim
39 words
The system of claim 15 wherein said means for supervising includes circuit means coupling from each receiver transducer for initiating an alarm signal upon the absence of a signal of first frequency from any one of said receiver transducers.
Claim 20
Dependent Claim
34 words
The system of claim 16 wherein said circuit means comprises a plurality of transistors and means for maintaining all the transistors in a like state when all the first frequency signals are being received.
Claim 21
Independent Claim
97 words
A system for detecting breakage of a solid material comprising; a transmitter transducer associated with the material for establishing a signal of first frequency in the material, said material creating a signal of second frequency when broken, a receiver transducer for receiving a control signal which is said first frequency signal when no breakage occurs and a composite of said first and second frEquency signals when breakage occurs, means for detecting said composite control signal to provide at least a third frequency signal, and means for indicating an alarm condition upon detection of said third frequency signal.
Claim 22
Independent Claim
97 words
A system for detecting breakage of a solid material comprising; a transmitter transducer associated with the material for establishing a signal of first frequency in the material, said material creating a signal of second frequency when broken, a receiver transducer for receiving a control signal which is said first frequency signal when no breakage occurs and a composite of said first and second frEquency signals when breakage occurs, means for detecting said composite control signal to provide at least a third frequency signal, and means for indicating an alarm condition upon detection of said third frequency signal.
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) | 1978-06-09 | 1978-12-09 | 1979-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-09 | 1982-12-09 | 1983-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-09 | 1986-12-09 | 1987-06-10 | $7700.00 | Window Closed / Lapsed |