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:
May. 05, 1998
Filed:
Jan. 30, 1997
Applicant:
Inventors:
Richard S Jones, West Columbia, SC (US);
N Rodgers Williamson, Jr, Leesville, SC (US);
Assignee:
Union Switch & Signal Inc., Pittsburgh, PA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B61L / ;
U.S. Cl.
CPC ...
318266 ; 318286 ; 318380 ; 318468 ; 246125 ;
Abstract
A highway crossing gate control circuit is provided which minimizes the 'pumping' oscillation of a highway crossing gate arm which is driven up by a permanent magnet motor. A preferred embodiment of the control circuit utilizes a p-channel MOSFET in a power down module of the control circuit to restrict power from being applied to the motor when the gate arm is in an up position and is intended to be held in the up position by a hold clear device which acts as a mechanical break. Provision is included for dynamic braking on the gate arm moving downward after an initial drive down mode.