Railroad grade crossing constant warning protection system
US4307860A · kind A · utility
24Cited by
4References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 30, 1979 |
| Grant date | Dec 29, 1981 |
| Priority date | — |
| Expiry date | Jul 30, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB61L29/286
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A train detection system for protecting a railroad highway crossing having an a.c. transmitter center-feeding voltage signals into the track rails and having a receiver including at least a pair of coils located on opposite sides of the crossing and disposed adjacent the track rails for defining an island zone and for inductively picking up a.c. signals when the island zone is unoccupied and determines the time of arrival of a train at the crossing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.