US3631450A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic alarm device
Assignee: Individual
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Filing: 1969-08-27
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Granted: 1971-12-28
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Expires: 1989-08-27
Abstract
Abstract A loudspeaker is adapted to be energized by an alternating current signal to provide an audible output signal of progressively increasing intensity. An alarm controlled switch applies the signal to a loudspeaker. The increase in intensity of the audible signal is facilitated by a thermistor connected in series with the loudspeaker. A high-pass filter and rectifier circuit in series with the thermistor enhance the production of harmonics of the signal frequency thereby to provide an improved audio tone and to permit said tone, or alarm signal, to be readily heard over a broad intensity range. A vibrator attached to the speaker provides a second audible signal after a predetermined audio intensity is achieved.
Inventors
- 👤 John W Chalfant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:25
CPC Classifications
G; G08; G08B; G08B3/00; G08B3/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
159 words
An acoustic alarm device comprising in combination a sound transducing means, switch means for applying a low-frequency alternating current voltage signal to said sound transducing means thereby to produce an audible signal varying in content with the frequency and amplitude of said voltage signal, impedance means coupled in circuit with said transducing means and said switch means for increasing as a function of time the amplitude of said voltage signal that is applied to said transducing means whereby the loudness of said audible sigNal progressively increases with time, harmonic generating means coupled in circuit with said transducing means for generating harmonics of said voltage signal for application to said transducing means thereby producing an audible alarm signal improved in tonal quality and containing frequencies in the sensitive human hearing range where changes in alarm intensity are the most easily discernible, a vibrator means adapted to be mechanically energized by said transducer means thereby to produce a second audible signal.
Claim 2
Dependent Claim
159 words
An acoustic alarm device comprising in combination a sound transducing means, switch means for applying a low-frequency alternating current voltage signal to said sound transducing means thereby to produce an audible signal varying in content with the frequency and amplitude of said voltage signal, impedance means coupled in circuit with said transducing means and said switch means for increasing as a function of time the amplitude of said voltage signal that is applied to said transducing means whereby the loudness of said audible sigNal progressively increases with time, harmonic generating means coupled in circuit with said transducing means for generating harmonics of said voltage signal for application to said transducing means thereby producing an audible alarm signal improved in tonal quality and containing frequencies in the sensitive human hearing range where changes in alarm intensity are the most easily discernible, a vibrator means adapted to be mechanically energized by said transducer means thereby to produce a second audible signal.
Claim 3
Dependent Claim
186 words
An acoustic alarm device comprising in combination a sound transducing means, switch means for applying a low-frequency alternating current voltage signal to said sound transducing means thereby to produce an audible signal varying in content with the frequency and amplitude of said voltage signal, impedance means coupled in circuit with said transducing means and said switch means for increasing as a function of time the amplitude of said voltage signal that is applied to said transducing means whereby the loudness of said audible signal progressively increases with time, harmonic generating means coupled in circuit with said transducing means for generating harmonics of said voltage signal for application to said transducing means thereby producing an audible alarm signal improved in tonal quality and containing frequencies in the sensitive human hearing range where changes in alarm intensity are the most easily discernible, wherein said transducer means is a loudspeaker having a voice coil and a vibrator secured at one end to said loudspeaker and adapted to be struck at the other end by the movement of said voice coil thereby to produce vibratory energy in an audible range.
Claim 4
Dependent Claim
186 words
An acoustic alarm device comprising in combination a sound transducing means, switch means for applying a low-frequency alternating current voltage signal to said sound transducing means thereby to produce an audible signal varying in content with the frequency and amplitude of said voltage signal, impedance means coupled in circuit with said transducing means and said switch means for increasing as a function of time the amplitude of said voltage signal that is applied to said transducing means whereby the loudness of said audible signal progressively increases with time, harmonic generating means coupled in circuit with said transducing means for generating harmonics of said voltage signal for application to said transducing means thereby producing an audible alarm signal improved in tonal quality and containing frequencies in the sensitive human hearing range where changes in alarm intensity are the most easily discernible, wherein said transducer means is a loudspeaker having a voice coil and a vibrator secured at one end to said loudspeaker and adapted to be struck at the other end by the movement of said voice coil thereby to produce vibratory energy in an audible range.
Claim 5
Dependent Claim
179 words
An acoustic alarm device comprising in combination a sound transducing means, switch means for applying a low-frequency alternating current voltage signal to said sound transducing means thereby to produce an audible signal varying in content with the frequency and amplitude of said voltage signal, impedance means coupled in circuit with said transducing means and said switch means for increasing as a function of time the amplitude of said voltage signal that is applied to said transducing means whereby the loudness of said audible signal progressively increases with time, harmonic generating means coupled in circuit with said transducing means for generating harmonics of said voltage signal for application to said transducing means thereby producing an audible alarm signal improved in tonal quality and containing frequencies in the sensitive human hearing range where changes in alarm intensity are the most easily discernible wherein said transducer means is a loudspeaker having a voice coil and a vibrator secured to one end to the cone of said loudspeaker whereby movement of said cone produces vibratory energy in said vibrator in an audible range.
Claim 6
Dependent Claim
179 words
An acoustic alarm device comprising in combination a sound transducing means, switch means for applying a low-frequency alternating current voltage signal to said sound transducing means thereby to produce an audible signal varying in content with the frequency and amplitude of said voltage signal, impedance means coupled in circuit with said transducing means and said switch means for increasing as a function of time the amplitude of said voltage signal that is applied to said transducing means whereby the loudness of said audible signal progressively increases with time, harmonic generating means coupled in circuit with said transducing means for generating harmonics of said voltage signal for application to said transducing means thereby producing an audible alarm signal improved in tonal quality and containing frequencies in the sensitive human hearing range where changes in alarm intensity are the most easily discernible wherein said transducer means is a loudspeaker having a voice coil and a vibrator secured to one end to the cone of said loudspeaker whereby movement of said cone produces vibratory energy in said vibrator in an audible range.
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) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |