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:
Jan. 19, 2010
Filed:
Jun. 05, 2007
Thomas J. Heyden, Arlington Heights, IL (US);
Lowell Ziese, Pewaukee, WI (US);
Thomas J. Heyden, Arlington Heights, IL (US);
Lowell Ziese, Pewaukee, WI (US);
AAA Sales & Engineering, Inc., Oak Creek, WI (US);
Abstract
A railcar presence detector including magnetic field sensors spaced along the length of a rail track for detecting magnetic field disturbances caused by ferromagnetic objects, such as railcars, passing along the rail track. Each of the magnetic field sensors generates an output signal that is received by a control unit. The control unit compares the output signal from each of the magnetic field sensors to a detection threshold and controls the position of a contact member dependent upon the comparison between the output signal and the detection threshold. Each of the magnetic field sensors includes a test device that is selectively operable to modify the magnetic field near the magnetic field sensor to test the operation of the magnetic field sensor. During operation of the system including the magnetic field sensor, the control unit can automatically activate the test device to assure that each of the magnetic field sensors are operating properly.