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:
Feb. 15, 1983
Filed:
May. 15, 1981
Applicant:
Inventor:
Toshiaki Ishii, Inazawa, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B66B / ;
U.S. Cl.
CPC ...
187 / ;
Abstract
A speed control apparatus for an elevator wherein a current command signal for controlling the firing angle of dual thyristor converters is supplied through a filter circuit. On switching from one converter to the other pursuant to reversing the elevator direction, the filter circuit is reset to bring the current command signal momentarily to zero, after which it rises smoothly in a positive or negative direction together with the elevator motor armature current.