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. 11, 1988
Filed:
Jan. 25, 1988
James L Lagree, Plum Borough, PA (US);
Richard A Johnson, Murrysville, PA (US);
Dirk J Boomgaard, Monroeville, PA (US);
Daphne C D'Zurko, Parsippany, NJ (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
A feedback controlled elevator door control system 30 having motoring and generating modes, including a DC motor 35 connected to a DC power supply 36 via a power bridge circuit 68. Protective features include a dynamic current limit reference 200 having a magnitude which changes with motor speed; control 116 for providing an object detection safety-stop speed pattern having parameters which are selectable independent of the door stopping portions of normal opening and closing speed patterns; a bridge monitor 66 which prevents the changing of door commands when motor reversal could cause a bridge short; a power supply monitor 40 which blocks door commands when the control voltage is below standard; and an over-voltage protection monitor 38 which protects against excessive voltage build-up on DC power supply components when the bridge circuit 68 pumps power back to the DC power supply 36 during a generating mode.