US3569635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
A telecommunication system with means for detecting faults and rerouting signals to the fault locations
Assignee: International Standard Electric Corp
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Filing: 1967-10-10
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Granted: 1971-03-09
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Expires: 1987-10-10
Abstract
Abstract A telecommunications system includes a master station which is in communication with any one of a number of outstations via one or the other leg of the two legs of a closed loop cable linking all the outstations along the cable route. A pilot tone is transmitted around the loop (which may be a four-wire telephone circuit) to indicate the occurrence of a fault and simultaneously to initiate switching operations to switch outstations beyond the fault to a healthy leg and isolate the faulty section of the line.
Inventors
- 👤 Cyril Ettienne Bloch
- 👤 Victor Teacher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:26
CPC Classifications
H; H04; H04Q; H04Q5/00; H04Q5/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
216 words
A telecommunication system comprising a master station, a plurality of outstations, a cable route including first and second chains of cable links for connecting the outstations together, first and second ends of the chains of said cable route each terminating at the master station as part of a closed loop, each outstation incorporating first and second coupling means connected between adjacent links of the cable route to complete the closed loop, the master station including means for applying a pilot signal to a first cable link at the second ends of the chains of said cable route and over that cable link and the first coupling means of an outstation to first coupling means of successive outstations, means connecting said first ends of the chains of said cable route to intelligence signal-transmitting and receiving means respectively of the master station, means connecting said first ends of said first and second chains of said cable route to pilot signal-receiving and transmitting means of the master station, pilot signal-coupling means connectable between said intelligence signal-transmitting and receiving means in such a manner that when each said chain is operative said pilot signal is transmitted from said master station via said second chain to said pilot signal-coupling means and thence via said first chain back to said master station.
Claim 2
Dependent Claim
216 words
A telecommunication system comprising a master station, a plurality of outstations, a cable route including first and second chains of cable links for connecting the outstations together, first and second ends of the chains of said cable route each terminating at the master station as part of a closed loop, each outstation incorporating first and second coupling means connected between adjacent links of the cable route to complete the closed loop, the master station including means for applying a pilot signal to a first cable link at the second ends of the chains of said cable route and over that cable link and the first coupling means of an outstation to first coupling means of successive outstations, means connecting said first ends of the chains of said cable route to intelligence signal-transmitting and receiving means respectively of the master station, means connecting said first ends of said first and second chains of said cable route to pilot signal-receiving and transmitting means of the master station, pilot signal-coupling means connectable between said intelligence signal-transmitting and receiving means in such a manner that when each said chain is operative said pilot signal is transmitted from said master station via said second chain to said pilot signal-coupling means and thence via said first chain back to said master station.
Claim 3
Dependent Claim
96 words
A telecommunications system as claimed in claim 1, wherein said master station comprises resettable switching means, said means being reset in response to loss of the pilot signal indicating signals to certain outstations have been cut off by a fault, said switching means providing a connection between the first end of the first chain and the second end of the second chain and a further connection betwEen the first end of the second chain and the second end of the first chain to enable transmission of intelligence signals to the outstations cut off by the fault.
Claim 4
Dependent Claim
76 words
A telecommunication system as claimed in claim 2, comprising further switching means at each outstation which is caused to operate by the response of the switching means at one said outstation and which, when operated, causes an interruption in both of the cable links between said one outstation and the next adjacent outstation along said route in the direction towards said second ends to prevent possible reception of signals over two paths having different propagation times.
Claim 5
Dependent Claim
37 words
A telecommunication system as claimed in claim 3, wherein said master station monitors the condition of said further switching means so as to set said resettable switching means only after the operation of said further switching means.
Claim 6
Dependent Claim
20 words
A telecommunications system as claimed in claim 2, wherein said resettable switching means, when set, disables said pilot signal-coupling means.
Claim 7
Dependent Claim
41 words
A telecommunications system as claimed in claim 1, wherein said pilot signal is an alternating current signal of a frequency not included in the frequency range of said intelligence signals, and wherein said pilot signal coupling means is a band-pass filter.
Claim 8
Dependent Claim
60 words
A telecommunications system as claimed in claim 3, wherein each outstation includes intelligence signal-transmitting and receiving means connected under control of said further switching means, and wherein operation of said further switching means in response to said failure causes the outstation intelligence signal transmitting and receiving means to be connected to said first and said second signal coupling means respectively.
Claim 9
Dependent Claim
163 words
A telecommunications system as claimed in claim 7, wherein each said signal-coupling means comprises a hybrid device having four ports, wherein the first one of said four ports is connected to the link over which the outstation in normal operation of the system receives intelligence signals, the second one of said four ports is connected to the link over which the outstation in normal operation of the system transmits intelligence signals, the third one of said four ports is connected by said further switching means to the intelligence signal-transmitting means of said outstation, and the fourth one of said four ports is connected by said further switching means to the intelligence signal-receiving means of said outstation, the arrangement of the hybrid device being such that each odd-numbered port is coupled to both even-numbered ports and substantially isolated from the respective other odd-numbered port, and that each even-numbered port is coupled to both odd-numbered ports and substantially isolated from the respective other even-numbered port.
Claim 10
Dependent Claim
39 words
A telecommunications system as claimed in claim 9, wherein said fourth port of the hybrid device of each of said two signal-coupling means is individually coupled to pilot signal-detecting means coupled via logic circuit means to said switching means.
Claim 11
Dependent Claim
76 words
A telecommunications system as claimed in claim 9, wherein said logic circuit means comprises a first and a second NOR gate, wherein the pilot signal-detecting means associated with said first chain is coupled via a first one of two inputs of the first NOR gate to said switching means, and wherein the pilot signal detecting means associated with said second chain is coupled via the second NOR gate to the second one of said two inputs.
Claim 12
Dependent Claim
68 words
A telecommunications system as claimed in claim 1, in which the master station comprises a program storage device controlling via logic circuit devices means for addressing outstations individually by coded address intelligence signals, means for interrogating outstations to cause them to transmit stored information to the master station and means for operating the receiving means of an addressed outstation to cause a predetermined control function to be effected.
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) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |