US3246143A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Railroad grade crossing protection system
Assignee: Southern Pacific Co
•
Filing: 1963-09-30
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Granted: 1966-04-12
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Expires: 1983-09-30
Abstract
No abstract record available.
Inventors
- 👤 Carroll M Steele
- 👤 Arlo C Krout
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:51
CPC Classifications
B; B61; B61L; B61L29/00; B61L29/24; B61L29/28; B61L29/286
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
96 words
APPARATUS FOR DERIVING FROM RAILROAD TRACKS INFORMATION FOR PREDICTING THE TIME REQUIRED FOR ARRIVAL AT A GIVEN LOCATION OF A DISTANT TRAIN WHICH IS MOVING ON SAID TRACKS TOWARD SAID LOCATION COMPRISING MEANS FOR APPLYING AN ALTERNATING-CURRENT SIGNAL WITH A CONSTANT-CURRENT LEVEL TO SAID TRACKS AT SAID LOCATION, MEANS FOR DERIVING A FIRST VOLTAGE AT SAID LOCATION FROM SAID TRACKS WHICH IS REPRESENTATIVE OF THE DISTANCE OF SAID TRAIN FROM SAID LOCATION, MEANS FOR DIFFERENTIATING SAID FIRST VOLTAGE TO OBTAIN A SECOND VOLTAGE REPRESENTATIVE OF THE INSTANTANEOUS SPEED OF SAID TRAIN, AND MEANS FOR COMBINING SAID
Claim 2
Dependent Claim
96 words
APPARATUS FOR DERIVING FROM RAILROAD TRACKS INFORMATION FOR PREDICTING THE TIME REQUIRED FOR ARRIVAL AT A GIVEN LOCATION OF A DISTANT TRAIN WHICH IS MOVING ON SAID TRACKS TOWARD SAID LOCATION COMPRISING MEANS FOR APPLYING AN ALTERNATING-CURRENT SIGNAL WITH A CONSTANT-CURRENT LEVEL TO SAID TRACKS AT SAID LOCATION, MEANS FOR DERIVING A FIRST VOLTAGE AT SAID LOCATION FROM SAID TRACKS WHICH IS REPRESENTATIVE OF THE DISTANCE OF SAID TRAIN FROM SAID LOCATION, MEANS FOR DIFFERENTIATING SAID FIRST VOLTAGE TO OBTAIN A SECOND VOLTAGE REPRESENTATIVE OF THE INSTANTANEOUS SPEED OF SAID TRAIN, AND MEANS FOR COMBINING SAID
References Cited (Backward Citations)
US2755439A
Cited
US2930888A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-04-11 | 1969-10-11 | 1970-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-04-11 | 1973-10-11 | 1974-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-04-11 | 1977-10-11 | 1978-04-12 | $7700.00 | Window Closed / Lapsed |