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. 14, 1985
Filed:
Mar. 09, 1983
Nobuo Anzai, Inazawa, JP;
Hiroyuki Ikejima, Inazawa, JP;
Abstract
An apparatus for controlling an A-C powered elevator wherein: when a frequency instruction value lies within a predetermined frequency range, an inverter in the apparatus produces an A-C electric power having a frequency which lies outside said predetermined frequency range, so that the frequency of the electrical power supplied from said inverter to the motor driving an elevator cage will be out of the resonant frequency range of the mechanical system of the elevator. Namely, an inverter is connected to a D-C power supply, the inverter is controlled by a voltage instruction value and a frequency instruction value, a D-C electric power is converted into the A-C electric power having a variable voltage and a variable frequency by said inverter, and an A-C electric motor is powered by the thus converted A-C electric power to drive an elevator cage, wherein a frequency conversion computer is provided which, when said frequency instruction value lies within a predetermined frequency range, sends to said inverter a frequency instruction value which lies outside said frequency range.