US3872261A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switching apparatus for use in a paging system of a key telephone system
Assignee: NEC Platforms Ltd
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Filing: 1973-04-05
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Granted: 1975-03-18
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Expires: 1993-04-05
Abstract
Abstract Switching apparatus for use in a paging system of a key telephone system is disclosed by which voice paging signals, central office arrival signals and other signals can be transmitted to multiple internal zones, made up of a plurality of key telephones having internal amplifiers and speakers. Additionally both voice paging signals and at least one other signal can be transmitted to multiple external zones comprising speakers only. By the proper selection of connections various combinations of internal and external zones are possible.
Inventors
- 👤 Tsuyoshi Shinoi
- 👤 Fumio Tsutsumi
- 👤 Stephen E Kerman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:45
CPC Classifications
H; H04; H04M; H04M11/00; H04M11/02; H04M11/022
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
167 words
A switching circuit means for use in audible signal and intercom speech circuits of a key telephone system having a plurality of key telephone sets, each having an audible signal and an input terminal, an internal amplifier and a speaker; the switching circuit means comprising; an audio signal generating means having a first output signal connected to a first terminal means; a central office line circuit means having a second output signal connected to a second terminal means; an intercom line circuit means having a third output signal from the intercom speech circuits of the key telephone system connected to a third output terminal; and switching means connected between the three output terminal means and the input terminals of a preselected group of key telephone sets, the switching means disconnecting said audio signal generating means from said key telephone group in response to an output signal from one of said line circuit means and connecting the output of said line circuit means to said key telephone sets.
Claim 2
Dependent Claim
167 words
A switching circuit means for use in audible signal and intercom speech circuits of a key telephone system having a plurality of key telephone sets, each having an audible signal and an input terminal, an internal amplifier and a speaker; the switching circuit means comprising; an audio signal generating means having a first output signal connected to a first terminal means; a central office line circuit means having a second output signal connected to a second terminal means; an intercom line circuit means having a third output signal from the intercom speech circuits of the key telephone system connected to a third output terminal; and switching means connected between the three output terminal means and the input terminals of a preselected group of key telephone sets, the switching means disconnecting said audio signal generating means from said key telephone group in response to an output signal from one of said line circuit means and connecting the output of said line circuit means to said key telephone sets.
Claim 3
Dependent Claim
90 words
A switching circuit as in claim 1 further comprising means for connecting up a plurality of key telephone sets in a plurality of zones each of the zones being connected to at least one of the outputs from said audio signal generating means, said central office line circuit means and said intercom line circuit means and, means for selectively connecting an output signal from said audio signal generating means, central office line circuit means and intercom line circuit means to at least one Preselected zone, independent of said other zones.
Claim 4
Dependent Claim
106 words
A switching circuit means as in claim 1 further comprising; amplifying means coupled to the first and third output terminals; a plurality of speakers, coupled to the output of said amplifying means, said comprising an external zone; and means for disconnecting said amplifying means from said first output terminal and connecting said amplifying means to said third output terminal in response to an output signal from said intercom line circuit means, said disconnecting means also disconnecting said amplifying means from said third output terminal and reconnecting said amplifying means to said audio signal means upon the termination of the signal from said intercom line circuit means.
Claim 5
Dependent Claim
92 words
A switching circuit means as in claim 3 further comprising; means for interconnecting a plurality of key telephone sets, each having internal speakers and amplifiers, with the plurality of said speakers, said combination of key telephone sets and speakers forming a second zone; means for connecting said second zone to said audio generating means and said intercom line circuit means, and said disconnecting means; and means for selectively coupling said external zone and said second zone to said audio generating means and said intercom line circuit means independent of said other zone.
Claim 6
Dependent Claim
108 words
A switching circuit means as in claim 4 in which said second zone comprises; a first, second and third sub-zone; said first sub-zone comprised of key telephone sets, each of said sets having internal speakers and amplifiers; said second sub-zone comprised of a plurality of speakers; said third sub-zone comprised of a combination of speakers and key telephones having internal speakers and amplifiers; and means for selectively connecting said sub-zones to said audio signal generating means, central office line circuit means and said intercom circuit means to form a plurality of sub-zones in which each sub-zone is connected and disconnected to said means independent of each other sub-zone.
Claim 7
Dependent Claim
33 words
A switching circuit means as in claim 5 further comprising means for connecting all zones and sub-zones to said intercom line circuit means for permitting intercom calling to all zones and sub-zones simultaneously.
References Cited (Backward Citations)
US3267219A
Cited
US3576397A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |