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. 12, 1988
Filed:
Jul. 29, 1987
Kazuhiro Sakata, Katsuta, JP;
Yoshio Sakai, Naka, JP;
Tsutomu Sano, Katsuta, JP;
Yoichi Ono, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a cage position detector for a hydraulic elevator, there is provided a detector for measuring the time duration of the power failure, when the power fails. An amount of sinkage of a cage during the power failure is obtained by the time duration of the power failure and an average sinkage amount per unit time provide in advance. A cage position, which has been detected just before the power failure, is corrected by the above obtained amount of sinkage of the cage. A cage position, from which the elevator is to reopen a normal operation for service after the recovery of power, is specified by the corrected cage position. According to the present invention, even though the cage sinks during the long power failure, it is prevented to lose the true present position of the cage, from which the elevator is to reopen the normal operation after the recovery of power.