US3893067A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Traffic signal control system
Assignee: Omron Corp
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Filing: 1973-03-16
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Granted: 1975-07-01
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Expires: 1993-03-16
Abstract
Abstract Fail-safe apparatus is provided for controlling traffic signals upon failure of an electronic computer. The computer normally controls traffic signals at a multiplicity of intersections. The computer and the fail-safe apparatus count the indication times of the traffic signals in synchronism. The indications of the traffic signals are controlled, upon failure of the computer, in accordance with signals generated corresponding to each countout of the indication times by the fail-safe apparatus.
Inventors
- 👤 Hiroo Watanabe
- 👤 Minoru Nagao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:35
CPC Classifications
G; G08; G08G; G08G1/00; G08G1/07; G08G1/081
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
159 words
A traffic signal control system for controlling traffic signals at a multiplicity of intersections, comprising, a computer for counting first phase time of traffic signals and generating first signals for advancing phases of the traffic signals upon each countout of the first phase times, a fail-safe apparatus, in which second phase times of the traffic signals are set, and to which said first phase advance signals generated by said computer are supplied, said fail-safe apparatus commencing the count of the second phase times in accordance with said first phase advance signals from said computer when said computer is normally operating, and for generating second signals for advancing the phases of said traffic signals upon attaining a count of said set second phase times, and logic switch means for transmitting said first phase advance signals from said computer when said computer is normally operating, and for transmitting said second phase advance signals from said fail-safe apparatus when said computer fails.
Claim 2
Dependent Claim
159 words
A traffic signal control system for controlling traffic signals at a multiplicity of intersections, comprising, a computer for counting first phase time of traffic signals and generating first signals for advancing phases of the traffic signals upon each countout of the first phase times, a fail-safe apparatus, in which second phase times of the traffic signals are set, and to which said first phase advance signals generated by said computer are supplied, said fail-safe apparatus commencing the count of the second phase times in accordance with said first phase advance signals from said computer when said computer is normally operating, and for generating second signals for advancing the phases of said traffic signals upon attaining a count of said set second phase times, and logic switch means for transmitting said first phase advance signals from said computer when said computer is normally operating, and for transmitting said second phase advance signals from said fail-safe apparatus when said computer fails.
Claim 3
Dependent Claim
32 words
A traffic signal control system according to claim 1, wherein said fail-safe apparatus includes means responsive to said computer for setting the second phase times in said fail-safe apparatus by said computer.
Claim 4
Dependent Claim
26 words
A traffic signal control system according to claim 1, wherein said fail-safe apparatus includes means for manually setting said second phase times in said fail-safe apparatus.
Claim 5
Dependent Claim
70 words
A traffic signal control system according to claim 1, wherein said fail-safe apparatus includes: means for generating clock pulses, first means in which the second phase times are set and providing an output value indicative thereof, second means for counting the clock pulses, and third means for generating second phase advance signals upon coincidence of the count value of said second means with said output value of said first means.
Claim 6
Dependent Claim
53 words
A traffic signal control system according to claim 4, further including means for interrupting the supply of said clock pulses to said second means for a time period between the second generation of the phase advance signal by the third means and the generation of a first phase advance signal by said computer.
Claim 7
Dependent Claim
59 words
A traffic signal control system according to claim 4, wherein said first means includes a plurality of registers, each of said registers storing a value corresponding to a different phase time, said third means comparing the value of each of said registers with the count value of said second means for generating second phase advance signals upon coincidence thereof.
Claim 8
Dependent Claim
26 words
A traffic signal control system according to claim 6, further comprising means for sequentially supplying the output of each of said registers to said third means.
Claim 9
Dependent Claim
35 words
A traffic signal control system according to claim 7, wherein said means for sequentially supplying includes a counter for enabling a gating means at the output of each of said registers in a predetermined sequence.
Claim 10
Dependent Claim
21 words
A traffic signal control system according to claim 8, wherein said registers store a signal value therein supplied by said computer.
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) | 1978-06-30 | 1978-12-30 | 1979-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-30 | 1982-12-30 | 1983-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-30 | 1986-12-30 | 1987-07-01 | $7700.00 | Window Closed / Lapsed |