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:
Apr. 18, 1978
Filed:
Mar. 30, 1976
Minoru Tezuka, Yokohama, JA;
Yastami Kito, Tokyo, JA;
Nippon Otis Elevator Company, Tokyo, JA;
Kabushiki Kaisha Meidensha, Tokyo, JA;
Abstract
A control apparatus for an elevator system in which a rotation speed of a drive motor for driving said elevator system is controlled by supplying a deviation signal obtained by comparing a speed signal of said drive motor including an induction motor with a driving pattern setting signal; said control apparatus comprising a speed control circuit which includes a control amplifier, and is characterized in that a time constant value of the control amplifier is set to different values in constant running operation and in retardation control of the elevator. Additionally, said control apparatus is characterized that the time constant value in retardation control is set so as to make low a transient gain of said control amplifier, and further that a preselected bias is supperimposed to a time constant circuit of said control amplifier at an alternating point from a constant speed running to a slowing down of the elevator, in order to prevent the decrement of the transient gain.