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:
Jul. 21, 1987
Filed:
May. 13, 1985
Applicant:
Inventor:
Hiroyuki Ikejima, Inazawa, JP;
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B66B / ;
U.S. Cl.
CPC ...
187119 ;
Abstract
The present invention relates to a speed control apparatus for an elevator wherein direct current is inverted into alternating current of variable voltage and variable frequency by a current-control type inverter and wherein an induction motor is driven by the inverted A.C. power so as to operate a cage, the speed control apparatus comprising control means to intensify a field of the induction motor beforehand at the time of start of the elevator and to reduce it down to a predetermined value after the start.