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Patent US4031333A successfully refreshed from Google Patents.
US4031333A
Expired / Lapsed
US
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Circuit to indicate the simultaneous off-hook condition of at least two of a plurality of telephone subsets on the same telephone line
Assignee: International Telephone and Telegraph Corp
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Filing: 1976-07-14
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Granted: 1977-06-21
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Expires: 1996-07-14
Abstract
Abstract A visual indicator is contained in each of a plurality of telephone subsets on the same telephone line. A logic circuit is connected between the hookswitch of each of the plurality of telephone subsets and each of the visual indicators to activate the visual indicators when at least two of the plurality of subsets are detected to be in an off-hook condition simultaneously.
Inventors
- 👤 George Thomas Fouratt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:41
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/68; H04M1/70
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
121 words
An indicator circuit for a telephone system to indicate when at least two of a plurality of telephone subsets on the same telephone line are simultaneously in an off-hook condition comprising: at least one indicator contained in one of said plurality of subsets which when activated indicates that at least said one of said plurality of subsets and another of said plurality of subsets are in said off-hook condition simultaneously; and a logic circuit coupled between all of said plurality of subsets and said indicator to produce an output signal to activate said indicator when at least said one of said plurality of subsets and said another of said plurality of subsets are detected to be in said off-hook condition simultaneously.
Claim 2
Dependent Claim
121 words
An indicator circuit for a telephone system to indicate when at least two of a plurality of telephone subsets on the same telephone line are simultaneously in an off-hook condition comprising: at least one indicator contained in one of said plurality of subsets which when activated indicates that at least said one of said plurality of subsets and another of said plurality of subsets are in said off-hook condition simultaneously; and a logic circuit coupled between all of said plurality of subsets and said indicator to produce an output signal to activate said indicator when at least said one of said plurality of subsets and said another of said plurality of subsets are detected to be in said off-hook condition simultaneously.
Claim 3
Dependent Claim
13 words
A circuit according to claim 1, wherein said indicator is a visual indicator.
Claim 4
Dependent Claim
34 words
A circuit according to claim 2, wherein said visual indicator is a first light emitting device disposed in one half of a split busy button disposed in said one of said plurality of subsets.
Claim 5
Dependent Claim
17 words
A circuit according to claim 3, wherein said first light emitting device is a light emitting diode.
Claim 6
Dependent Claim
76 words
A circuit according to claim 3, further including a second light emitting device disposed in the other half of said split busy lamp and a relay coupled between a hookswitch of all of said plurality of subsets and said second light emitting device, said relay being activated when said one of said plurality of subsets is in said off-hook condition to energize said second light emitting device to emit light indicating said telephone line is busy.
Claim 7
Dependent Claim
17 words
A circuit according to claim 5, wherein said second light emitting device is a light emitting diode.
Claim 8
Dependent Claim
77 words
A circuit according to claim 5, wherein said logic circuit includes a plurality of NOT gates each coupled to a different one of said plurality of subsets, a plurality of AND gates each coupled to a different pair of said plurality of NOT gates, a NOR gate coupled to the output of each of said plurality of AND gates, and a NOT gate coupled between the output of said NOR gate and said first light emitting device.
Claim 9
Dependent Claim
74 words
A circuit according to claim 1, wherein said logic circuit includes a plurality of NOT gates each coupled to a different one of said plurality of subsets, a plurality of AND gates each coupled to a different pair of said plurality of NOT gates, a NOR gate coupled to the output of each of said plurality of AND gates, and a NOT gate coupled between the output of said NOR gate and said indicator.
Claim 10
Dependent Claim
27 words
A circuit according to claim 1, wherein each of said plurality of subsets includes said indicator, and said logic circuit is coupled to each of said indicators.
Claim 11
Dependent Claim
15 words
A circuit according to claim 9, wherein each of said indicators is a visual indicator.
Claim 12
Dependent Claim
35 words
A circuit according to claim 10, wherein each of said visual indicators is a first light emitting device disposed in one half of a split busy button disposed in each of said plurality of subsets.
Claim 13
Dependent Claim
19 words
A circuit according to claim 11, wherein each of said first light emitting devices is a light emitting diode.
Claim 14
Dependent Claim
82 words
A circuit according to claim 11, further including a second light emitting device disposed in the other half of each of said split busy lamps; and a relay coupled between a hookswitch of all of said plurality of subsets and all of said second light emitting devices, said relay being activated when any one of said plurality of subsets is in said off-hook condition to energize each of said second light emitting devices to emit light indicating said telephone line is busy.
Claim 15
Dependent Claim
19 words
A circuit according to claim 13, wherein each of said second light emitting devices is a light emitting diode.
Claim 16
Dependent Claim
87 words
A circuit according to claim 13, wherein said logic circuit includes a first plurality of NOT gates each coupled to a different one of said plurality of subsets, a plurality of AND gates each coupled to a different pair of said first plurality of NOT gates, a NOR gate coupled to the output of each of said plurality of AND gates, and a second plurality of NOT gates each coupled between the output of said NOR gate and a different one of said first light emitting devices.
Claim 17
Dependent Claim
84 words
A circuit according to claim 9, wherein said logic circuit includes a first plurality of NOT gates each coupled to a different one of said plurality of subsets, a plurality of AND gates each coupled to a different pair of said first plurality of NOT gates a NOR gate coupled to the output of each of said plurality of AND gates, and a second plurality of NOT gates each coupled between the output of said NOR gate and a different one of said indicators.
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) | 1980-06-20 | 1980-12-20 | 1981-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-20 | 1984-12-20 | 1985-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-20 | 1988-12-20 | 1989-06-21 | $7700.00 | Window Closed / Lapsed |