US3297868A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Railway crossing signal systems
Assignee: Individual
•
Filing: 1963-01-21
•
Granted: 1967-01-10
•
Expires: 1983-01-21
Abstract
No abstract record available.
Inventors
- 👤 Shaw Norman Ridley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:04
CPC Classifications
B; B61; B61L; B61L29/00; B61L29/24; B61L29/246
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
91 words
IN RAILWAY CROSSING SIGNAL SYSTEMS A MULTI-CHANNEL RADIO TRANSMITTER ON A LOCOMOTIVE AND A SIGNAL CHANNEL RADIO RECEIVER SET AT EACH CROSSING SAID RECEIVERS BEING TUNED TO EACH RECEIVE ONLY ONE OF THE SEVERAL TONES OR FREQUENCIES WHICH CAN BE SELECTIVELY TRANSMITTED SAID RECEIVERS BEING ARRANGED IN A DEFINITE PROGRESSIVE ORDER WITH REGARD TO THE TONE OF EACH RECEIVER SO THAT THE OPERATOR AT THE LOCOMOTIVE CAN ACTIVATE THE RECEIVER AT THE NEXT UP-COMING CROSSING WITHOUT ACTIVATING THE NEXT SEVERAL RECEIVERS WHICH ARE TUNED TO RECEIVE ONLY IN THE OTHER TONES.
Claim 2
Dependent Claim
91 words
IN RAILWAY CROSSING SIGNAL SYSTEMS A MULTI-CHANNEL RADIO TRANSMITTER ON A LOCOMOTIVE AND A SIGNAL CHANNEL RADIO RECEIVER SET AT EACH CROSSING SAID RECEIVERS BEING TUNED TO EACH RECEIVE ONLY ONE OF THE SEVERAL TONES OR FREQUENCIES WHICH CAN BE SELECTIVELY TRANSMITTED SAID RECEIVERS BEING ARRANGED IN A DEFINITE PROGRESSIVE ORDER WITH REGARD TO THE TONE OF EACH RECEIVER SO THAT THE OPERATOR AT THE LOCOMOTIVE CAN ACTIVATE THE RECEIVER AT THE NEXT UP-COMING CROSSING WITHOUT ACTIVATING THE NEXT SEVERAL RECEIVERS WHICH ARE TUNED TO RECEIVE ONLY IN THE OTHER TONES.
References Cited (Backward Citations)
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Cited
US1808022A
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US2028497A
Cited
US2252525A
Cited
US2460597A
Cited
US2607000A
Cited
US3182288A
Cited
US3114127A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-01-09 | 1970-07-11 | 1971-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-01-09 | 1974-07-11 | 1975-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-01-09 | 1978-07-11 | 1979-01-10 | $7700.00 | Window Closed / Lapsed |