The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 30, 2012
Filed:
Mar. 17, 2010
Randy M. O'dell, Blue Springs, MO (US);
Patrick J. Venneman, Blue Springs, MO (US);
Randy M. O'Dell, Blue Springs, MO (US);
Patrick J. Venneman, Blue Springs, MO (US);
Safetran Systems Corporation, Louisville, KY (US);
Abstract
A method and apparatus for controlling a grade crossing warning system employs a track occupancy circuit or other device to detect the presence of a train in the approach to a grade crossing and an indirect indication of a maximum authorized speed of the train in order to determine an amount of time to delay activation of the grade crossing warning system after the train has been detected. The indirect indication is preferably encoded onto a signal associated with the track occupancy circuit, preferably using a frequency shift technique. The indirect indication may be supplied by a wayside signal device.