US3863033A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Step-by-step telephone central exchanges for use with pcm communication networks
Assignee: GTE Automatic Electric Laboratories Inc
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Filing: 1973-04-30
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Granted: 1975-01-28
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Expires: 1993-04-30
Abstract
Abstract A conventional step-by-step telephone central exchange having line finder, selector and connector switches is modified for use with a PCM TDM communication switching system through elimination of the selector switches and through direct connection of selected numbers of line finder switches and connector switches to the originating channel units and terminating channel units, respectively, of a standard PCM channel bank assembly.
Inventors
- 👤 Chungmin Chen
- 👤 Michael J Kelly
- 👤 Bernard J Rekiere
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:10
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0016; H04Q11/00; H04Q11/04
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
299 words
An improved telephone communication exchange for linking subscriber lines with a PCM switching system comprising a preselected matrix of subscriber line pairs, line finder switching means operative to connect to an originating one of said subscriber line pairs, originating loop channel unit means directly connected to said line finder switching means for converting analog signals to logic level information, PCM channel means connected to receive said logic level information and including outgoing and incoming time multiplexed carrier mediums, terminating loop channel unit means connected to said PCM channel means for reconverting said logic level information to said analog signals, and connector switching means directly connected to said terminating channel means and operative to electricity connect to a terminating one of said subscriber line pairs for completing a call through said PCM switching system: said line finder switching means includes a vertical stepping magnet assembly, a rotary stepping magnet assembly, first counter circuit means including first voltage firing means for activating said first counter circuit means connected to said vertical magnet assembly, second counter circuit means including second voltage firing means for activating said second counter circuit means connected to said rotary magnet assembly, decode and dual tone selection circuit means connected to receive output signals from said first and second counter circuit means, respectively, for providing output signals to said PCM switching system containing subscriber identification, tone generator means connected to said decode and dual tone selection circuit means for providing predetermined dual tones thereto when said output signals from said first and second counter means are received, and means for selectively connecting the output signals of said first and second counter mean to said decode and dual tone selection circuit means and for selectively connecting the output signals of said selection circuit means to said PCM switching system.
Claim 2
Dependent Claim
299 words
An improved telephone communication exchange for linking subscriber lines with a PCM switching system comprising a preselected matrix of subscriber line pairs, line finder switching means operative to connect to an originating one of said subscriber line pairs, originating loop channel unit means directly connected to said line finder switching means for converting analog signals to logic level information, PCM channel means connected to receive said logic level information and including outgoing and incoming time multiplexed carrier mediums, terminating loop channel unit means connected to said PCM channel means for reconverting said logic level information to said analog signals, and connector switching means directly connected to said terminating channel means and operative to electricity connect to a terminating one of said subscriber line pairs for completing a call through said PCM switching system: said line finder switching means includes a vertical stepping magnet assembly, a rotary stepping magnet assembly, first counter circuit means including first voltage firing means for activating said first counter circuit means connected to said vertical magnet assembly, second counter circuit means including second voltage firing means for activating said second counter circuit means connected to said rotary magnet assembly, decode and dual tone selection circuit means connected to receive output signals from said first and second counter circuit means, respectively, for providing output signals to said PCM switching system containing subscriber identification, tone generator means connected to said decode and dual tone selection circuit means for providing predetermined dual tones thereto when said output signals from said first and second counter means are received, and means for selectively connecting the output signals of said first and second counter mean to said decode and dual tone selection circuit means and for selectively connecting the output signals of said selection circuit means to said PCM switching system.
Claim 3
Dependent Claim
186 words
An improved telephone communication exchange as claimed in claim 1 wherein said preselected matrix of subscriber line pairs is arranged in a plurality of like groups of subscriber line pairs, said vertical stepping magnet assembly is operative to connect said line finder switching means to a predetermined one of said like groups which includes said originating subscriber line pair and further is operative to provide an output signal to said first voltage firing means for each group to which said line finder switching means is connected, said rotary stepping magnet assembly is operative to connect said line finder switching means to said originating subscriber line pair within said predetermined group of sUbscriber line pairs of and to provide an output signal to said second voltage firing means for each subscriber line pair to which said line finder switching means is connected within said predetermined group thereof, and the output of said first counter circuit means corresponds to the group identification of said predetermined group and the output of said second counter circuit means corresponds to the subscriber line pair identification of said originating subscriber line pair.
Claim 4
Dependent Claim
55 words
An improved telephone communication exchange as claimed in claim 2 wherein said output signal of said second counter circuit means is connected to time delay means prior to being connected to said selection circuit means for providing that the output signal of said first counter circuit means is first received by said selection circuit means.
Claim 5
Dependent Claim
49 words
An improved telephone communication exchange as claimed in claim 2 wherein the group identification and the subscriber line pair identification comprises automatic number identification ANI provided to the PCM switching system by said decode and dual tone selection circuit means to control the operation of said connector switching means.
References Cited (Backward Citations)
US2863950A
Cited
US2829204A
Cited
US3087019A
Cited
US3458659A
Cited
US3496301A
Cited
US3585306A
Cited
US3778555A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-27 | 1978-07-29 | 1979-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-27 | 1982-07-29 | 1983-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-27 | 1986-07-29 | 1987-01-28 | $7700.00 | Window Closed / Lapsed |