Dual signal frequency motion monitor and broken rail detector
US4306694A · kind A · utility
36Cited by
8References
5Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 24, 1980 |
| Grant date | Dec 22, 1981 |
| Priority date | — |
| Expiry date | Jun 24, 2000 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB61L29/32
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A highway crossing warning system for monitoring the motion and predicting the time of arrival of an approaching train at the highway crossing and for detecting the presence of a broken rail in the approach zone by feeding dual frequency signals into the track rails and measuring the track impedances at the two frequencies and the phase angle of the lower of the two frequencies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.