Patent US3665116A successfully refreshed from Google Patents.
US3665116A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apartment house intercom system
Assignee: HS DEECO Inc A CORP OF
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Filing: 1969-12-19
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Granted: 1972-05-23
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Expires: 1989-12-19
Abstract
Abstract With this system only two wires are needed to transmit audio signals between a speaker-microphone unit located at a central or foyer station, and any one of a plurality of such units located at apartments remote from the foyer station. A transistorized relay at the central station normally connects the foyer unit for transmission to the remote units, but is responsive to a manually operable switch at each remote station to connect a selected remote unit for transmission to the foyer speaker. The same two wires are used to transmit a door unlatching signal from any remote unit to a release mechanism at the foyer station. Also, a buzzer energizing signal may be transmitted from the foyer station over a single line selectively to one of two of the remote apartment stations.
Inventors
- 👤 Allan Holstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:25
CPC Classifications
H; H04; H04M; H04M11/00; H04M11/02; H04M11/025
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
468 words
An intercom system for communicating selectively between a central station and one or more of a plurality of stations remote from said central station, comprising a combination speaker-microphone unit at each of said stations, a pair of conductors forming part of an audio signal circuit extending from said central station to each of said remote stations to convey audio signals from the unit at said central station to the unit at one of said remote stations, and vice versa, an audio amplifier at said central station, a direct current power supply for energizing said amplifier to enable transmission of audio signals therefrom, a first plurality of switches normally disposed in first positions in which they connect the output of the speakermicrophone unit at the central station to the input of said amplifier, and the output of said amplifier to one of said conductors, and a manually operable switch movable selectively to first and second positions, respectively, at each of said remote stations for selectively connecting the associated speaker-microphone unit between said pair of conductors for energization thereby, said amplifier being operative, when the manually operable switch at one of said remote stations is in its first position, to transmit audio signals from said unit at said central station to the input of the unit at said one remote station, means operative upon movement of the lasT-named switch to its second position to move the first-named plurality of switches to second positions in which they connect the output of the unit at said one remote station to the input of said amplifier, and connect the output of said amplifier to the input of said unit at said central station, and a relay coil operative, when energized, to move said first-named plurality of switches to their second positions, an electronic valve connected in series with said coil across said power supply and operative to block the flow of current through said coil, when the manually operable switch at each of said remote stations is in its first position, and means operative, upon the movement of the manually operable switch at any one of said remote stations to its second position, to render said valve conductive, thereby to energize said coil, a second relay coil connected at one end to the positive side of said power supply, and at its opposite end to said one conductor, and operative to control a circuit independent of the audio signal circuit, a second, normally open, manually operable switch connected between said pair of conductors at each of said remote stations and operative upon being closed to energize said second coil, and means for preventing energization of said second coil, when either of the first-named manually operable switches is in either its first or second operative position, and said second manually operable switch is open.
Claim 2
Dependent Claim
468 words
An intercom system for communicating selectively between a central station and one or more of a plurality of stations remote from said central station, comprising a combination speaker-microphone unit at each of said stations, a pair of conductors forming part of an audio signal circuit extending from said central station to each of said remote stations to convey audio signals from the unit at said central station to the unit at one of said remote stations, and vice versa, an audio amplifier at said central station, a direct current power supply for energizing said amplifier to enable transmission of audio signals therefrom, a first plurality of switches normally disposed in first positions in which they connect the output of the speakermicrophone unit at the central station to the input of said amplifier, and the output of said amplifier to one of said conductors, and a manually operable switch movable selectively to first and second positions, respectively, at each of said remote stations for selectively connecting the associated speaker-microphone unit between said pair of conductors for energization thereby, said amplifier being operative, when the manually operable switch at one of said remote stations is in its first position, to transmit audio signals from said unit at said central station to the input of the unit at said one remote station, means operative upon movement of the lasT-named switch to its second position to move the first-named plurality of switches to second positions in which they connect the output of the unit at said one remote station to the input of said amplifier, and connect the output of said amplifier to the input of said unit at said central station, and a relay coil operative, when energized, to move said first-named plurality of switches to their second positions, an electronic valve connected in series with said coil across said power supply and operative to block the flow of current through said coil, when the manually operable switch at each of said remote stations is in its first position, and means operative, upon the movement of the manually operable switch at any one of said remote stations to its second position, to render said valve conductive, thereby to energize said coil, a second relay coil connected at one end to the positive side of said power supply, and at its opposite end to said one conductor, and operative to control a circuit independent of the audio signal circuit, a second, normally open, manually operable switch connected between said pair of conductors at each of said remote stations and operative upon being closed to energize said second coil, and means for preventing energization of said second coil, when either of the first-named manually operable switches is in either its first or second operative position, and said second manually operable switch is open.
Claim 3
Dependent Claim
431 words
An intercom system for communicating selectively between a central station and one or more of a plurality of stations remote from said central station, comprising a combination speaker-microphone unit at each of said stations, a pair of conductors forming part of an audio signal circuit extending from said central station to each of said remote stations to convey audio signals from the unit at said central station to the unit at one of said remote stations, and vice versa, an audio amplifier at said central station, a direct current power supply for energizing said amplifier to enable transmission of audio signals therefrom, a first plurality of switches normally disposed in first positions in which they connect the output of the speaker-microphone unit at the central station to the input of said amplifier, and the output of said amplifier to one of said conductors, and a manually operable switch movable selectively to first and second positions, respectively, at each of said remote stations for selectively connecting the associated speaker-microphone unit between said pair of conductors for energization thereby, said amplifier being operative, when the manually operable switch at one of said remote stations is in its first position, to transmit audio signals from said unit at said central station to the input of the unit at said one remote station, means operative upon movement of the last-named switch to its second position to move the first-named plurality of switches to second positions in which they connect the output of the unit at said one remote station to the input of said amplifier, and connect the output of said amplifier to the input of said unit at said central station, electrically operable signal means at each of said remote stations, a plurality of manually operable signal switches at said central station, a further plurality of conductors extending between said central station and said remote stations, each of said further conductors connecting one of said signal switches to the signal means at one of said remote stations, and means operative, when said one signal switch is closed, to energize the associated signal means, each of said further conductors being connected at one end at said central station to two of said signal switches, and at its opposite end to the signal means at two different remote stations, and means operative, upon the closing of one of said two signal switches, to energize the signal means at one of said two stations, and operative upon the simultaneous closing of said two signal switches alternately to energize the associated signal means at said two remote stations.
Claim 4
Dependent Claim
431 words
An intercom system for communicating selectively between a central station and one or more of a plurality of stations remote from said central station, comprising a combination speaker-microphone unit at each of said stations, a pair of conductors forming part of an audio signal circuit extending from said central station to each of said remote stations to convey audio signals from the unit at said central station to the unit at one of said remote stations, and vice versa, an audio amplifier at said central station, a direct current power supply for energizing said amplifier to enable transmission of audio signals therefrom, a first plurality of switches normally disposed in first positions in which they connect the output of the speaker-microphone unit at the central station to the input of said amplifier, and the output of said amplifier to one of said conductors, and a manually operable switch movable selectively to first and second positions, respectively, at each of said remote stations for selectively connecting the associated speaker-microphone unit between said pair of conductors for energization thereby, said amplifier being operative, when the manually operable switch at one of said remote stations is in its first position, to transmit audio signals from said unit at said central station to the input of the unit at said one remote station, means operative upon movement of the last-named switch to its second position to move the first-named plurality of switches to second positions in which they connect the output of the unit at said one remote station to the input of said amplifier, and connect the output of said amplifier to the input of said unit at said central station, electrically operable signal means at each of said remote stations, a plurality of manually operable signal switches at said central station, a further plurality of conductors extending between said central station and said remote stations, each of said further conductors connecting one of said signal switches to the signal means at one of said remote stations, and means operative, when said one signal switch is closed, to energize the associated signal means, each of said further conductors being connected at one end at said central station to two of said signal switches, and at its opposite end to the signal means at two different remote stations, and means operative, upon the closing of one of said two signal switches, to energize the signal means at one of said two stations, and operative upon the simultaneous closing of said two signal switches alternately to energize the associated signal means at said two remote stations.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |