Patent US4219520A successfully refreshed from Google Patents.
US3819873A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone call indicator
Assignee: Individual
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Filing: 1972-05-02
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Granted: 1974-06-25
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Expires: 1992-05-02
Abstract
Abstract A telephone call indicator comprising an induction pickup coil for receiving a signal from a telephone set, means for amplifying said signal, a normally open latching switch in circuit with a visual signal and a power supply, and means for applying the amplified signal for closing said latching switch to effect energization of said visual signal, and a manually operated switch for resetting the device.
Inventors
- 👤 R Stockton
- 👤 M Croy
- 👤 R Hunter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:45
CPC Classifications
H; H04; H04M; H04M19/00; H04M19/02; H04M19/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
224 words
Telephone call indicator apparatus for use with a telephone, said apparatus comprising an induction coil for receiving an electromagnetic telephone ringing signal, a suction cup engaging said induction coil to said telephone, means for amplifying the received ringing signal, a normally nonconductive triggerable silicon controlled rectifier which is triggerable for becoming conductive and remaining conductive, a visual signalling device connected in a circuit with said silicon controlled rectifier for signalling when said silicon controlled rectifier is conductive, said signalling device including a filament connected in a series circuit with main electrodes of said silicon controlled rectifier across a power source, triggering circuit means for supplying the amplified ringing signal to said silicon controlled rectifier for triggering thereof thereby to cause said signalling device to provide continuing signalling indicative that there has been ringing of said telephone, said triggering circuit means comprising a resistive-capacitive timing circuit including a capacitor adapted for being charged through a resistor by said amplified ringing signal to a voltage sufficient for triggering said silicon controlled rectifier, said apparatus further comprising a reset switch also connected in said series circuit, said switch being manually operable for opening said series circuit to render said silicon controlled rectifier nonconductive, and a housing exclusive of said telephone for enclosing said amplifying means, said silicon controlled rectifier, said signalling device, and said triggering circuit means.
Claim 2
Dependent Claim
224 words
Telephone call indicator apparatus for use with a telephone, said apparatus comprising an induction coil for receiving an electromagnetic telephone ringing signal, a suction cup engaging said induction coil to said telephone, means for amplifying the received ringing signal, a normally nonconductive triggerable silicon controlled rectifier which is triggerable for becoming conductive and remaining conductive, a visual signalling device connected in a circuit with said silicon controlled rectifier for signalling when said silicon controlled rectifier is conductive, said signalling device including a filament connected in a series circuit with main electrodes of said silicon controlled rectifier across a power source, triggering circuit means for supplying the amplified ringing signal to said silicon controlled rectifier for triggering thereof thereby to cause said signalling device to provide continuing signalling indicative that there has been ringing of said telephone, said triggering circuit means comprising a resistive-capacitive timing circuit including a capacitor adapted for being charged through a resistor by said amplified ringing signal to a voltage sufficient for triggering said silicon controlled rectifier, said apparatus further comprising a reset switch also connected in said series circuit, said switch being manually operable for opening said series circuit to render said silicon controlled rectifier nonconductive, and a housing exclusive of said telephone for enclosing said amplifying means, said silicon controlled rectifier, said signalling device, and said triggering 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) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |