US4305556A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Railway control signal dynamic output interlocking systems
Assignee: Siemens Mobility Ltd
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Filing: 1979-05-23
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Granted: 1981-12-15
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Expires: 1999-05-23
Abstract
Abstract A computer based railway interlocking control system, having triple parallel redundant control computers (FIG. 2) provides greater system reliability as compared to a single computer system. The railway traffic control devices, e.g. points and signals, are arranged to be controlled by signals in one of two possible steady states, the interlocking control means (30, 31, 32, FIG. 2) is arranged to produce control signals in the steady state for de-energized or "safe" device settings and in an alternating state for energized or potentially "unsafe" settings. The alternating control signals (33, 34, 35 or 38) must be converted to the corresponding steady state to operate the devices thus, the converting or restoring circuit discriminates against dormant wrong side failures, i.e. "unsafe" signals to increase the inherent safety of the system.
Inventors
- 👤 David J. Norton
- 👤 Christopher R. Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:24
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/0796; B; B61; B61L; B61L1/00; B61L1/20; B61L19/00; B61L19/06; G06F11/16; G06F11/18; G06F11/183; G06F11/184; G06F11/181
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
159 words
A railway interlocking control system comprising a plurality of traffic control devices operative to alternative settings by steady state control signals, each of said traffic control devices having a potentially unsafe setting to which the device may be normally operated by a respective steady state control signal and wherein an erroneous control signal in the potentially unsafe state is by definition a wrong side failure, electronic or computer-based control signal interlocking means for, in normal operation, periodically switching control signals in a potentially unsafe first state between that first state and a relatively safer second state to produce an alternating control signal, signal restoring means, located between the interlocking means and the traffic control devices, for restoring alternating control signals to steady first state control signals, and steady first state signal detecting means, interposed between the interlocking means and the signal restoring means and responsive to steady state signals in the first state, for diagnosing potential wrong side failures.
Claim 2
Dependent Claim
159 words
A railway interlocking control system comprising a plurality of traffic control devices operative to alternative settings by steady state control signals, each of said traffic control devices having a potentially unsafe setting to which the device may be normally operated by a respective steady state control signal and wherein an erroneous control signal in the potentially unsafe state is by definition a wrong side failure, electronic or computer-based control signal interlocking means for, in normal operation, periodically switching control signals in a potentially unsafe first state between that first state and a relatively safer second state to produce an alternating control signal, signal restoring means, located between the interlocking means and the traffic control devices, for restoring alternating control signals to steady first state control signals, and steady first state signal detecting means, interposed between the interlocking means and the signal restoring means and responsive to steady state signals in the first state, for diagnosing potential wrong side failures.
Claim 3
Dependent Claim
21 words
Railway interlocking control means according to claim 1, wherein the interlocking control means is adapted to automatically produce an alternating signal.
Claim 4
Dependent Claim
40 words
Railway interlocking control means according to claim 1, wherein the interlocking control means is arranged to produce control signals in either first or second steady states and alternating signals are produced by switching means connected to the control means output.
Claim 5
Dependent Claim
17 words
A railway control system according to claim 1, comprising a plurality of parallel redundant interlocking control means.
Claim 6
Dependent Claim
42 words
A railway control system according to claim 4, wherein corresponding control signals generated by parallel interlocking control means are connected to respective inputs of an out-of-coincidence circuit responsive to non-unanimity of control signals to produce an output indicating an erroneous control signal.
Claim 7
Dependent Claim
36 words
A railway control system according to claim 5 wherein each input of the out-of-coincidence circuit is responsive only to steady state signals and is connected to respective control means outputs through alternating control signal converting means.
Claim 8
Dependent Claim
36 words
A railway control system according to claim 1 wherein control signals generated by parallel interlocking control means are compared by majority voting means responsive to a majority of equal corresponding signals to discard erroneous minority signals.
Claim 9
Dependent Claim
47 words
A railway control system according to claim 7 wherein alternating control signal converting means is connected between the individual output of the or each control means and the respective input to the majority voting means and the voting means is responsive only to steady state control signals.
Claim 10
Dependent Claim
45 words
A railway control system according to claim 7 wherein alternating control signal converting means is connected between the output of the majority voting means and the communication means connected to the control devices, and the majority voting means is responsive to alternating state control signals.
Claim 11
Dependent Claim
43 words
A railway control system according to claim 7 wherein the alternating control signal converting means is connected between the output of the communication means and the input to the control devices, and the majority voting means is responsive to alternating state control signals.
Claim 12
Dependent Claim
27 words
A railway control system as claimed in any one of claims 5, 6, 7, 8 and 9, wherein there are three parallel redundant railway interlocking control means.
Claim 13
Dependent Claim
31 words
A railway control system according to claim 11 wherein the interlocking control means is arranged to produce vital and non-vital control signals and only vital control signals have an alternating state.
Claim 14
Dependent Claim
33 words
A railway control system according to claim 11 including further electronic or computer-based apparatus connected to monitor control signals generated by the or each control means and arranged to diagnose erroneous control signals.
Claim 15
Dependent Claim
30 words
A railway control system according to claim 11 wherein control output signals are recorded by recording means adapted to maintain a recording of the signals for only a predetermined period.
References Cited (Backward Citations)
US3783250A
Cited
GB1489921A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-12-14 | 1985-06-15 | 1985-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-14 | 1989-06-15 | 1989-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-14 | 1993-06-15 | 1993-12-15 | $7700.00 | Window Closed / Lapsed |