Patent US3657486A successfully refreshed from Google Patents.
US3657486A
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Time division multiplex pax of the four wire type
Assignee: International Standard Electric Corp
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Filing: 1970-07-09
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Granted: 1972-04-18
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Expires: 1990-07-09
Abstract
Abstract This is a TDM-PAX of the four-wire type, in which the switches for the two directions of speech sample transmissions are physically separate from each other. This separation facilitates arranging the switches so that the proper matching of interswitch cabling is facilitated. Separate time positions are used within a slot for signalling and speech. Information other than speech is transmitted by varying the width of the crosspoint control pulses.
Inventors
- 👤 George Gara
- 👤 Roy Charles Thorncroft
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:14
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
126 words
An automatic telecommunication exchange, comprising telecommunication connections set up via time-division multiplex paths, each said connection using a separate path for the two directions of transmission, means for setting up each connection by inter-connecting the calling line and the wanted line via a switching stage, each switching stage including a switch for handling only the intelligence to be conveyed in one of said directions of transmission, the switches for said two directions of transmission being physically separated from each other, means to set up a connection via a crosspoint by enabling that crosspoint with a pulse applied thereto at the time position at which the connection is to be set up and conveying signals other than speech by varying the width of the crosspoint control pulses.
Claim 2
Dependent Claim
126 words
An automatic telecommunication exchange, comprising telecommunication connections set up via time-division multiplex paths, each said connection using a separate path for the two directions of transmission, means for setting up each connection by inter-connecting the calling line and the wanted line via a switching stage, each switching stage including a switch for handling only the intelligence to be conveyed in one of said directions of transmission, the switches for said two directions of transmission being physically separated from each other, means to set up a connection via a crosspoint by enabling that crosspoint with a pulse applied thereto at the time position at which the connection is to be set up and conveying signals other than speech by varying the width of the crosspoint control pulses.
Claim 3
Dependent Claim
55 words
An exchange as claimed in claim 1, in which supervisory connections are made from common control equipment to the multiplex highways, and said connections are enabled at times within the duration of a channel at which speech is not conveyed, so that separate portions of a channel time are used for speech and for supervision.
References Cited (Backward Citations)
US3132210A
Cited
US3213202A
Cited
US3311883A
Cited
US3281538A
Cited
US3300587A
Cited
US3291914A
Cited
US3366882A
Cited
US3458658A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-18 | 1975-10-18 | 1976-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-18 | 1979-10-18 | 1980-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-18 | 1983-10-18 | 1984-04-18 | $7700.00 | Window Closed / Lapsed |