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:
Nov. 30, 1993
Filed:
Mar. 09, 1992
Tsuyoshi Ogasawara, Ishioka, JP;
Ichiro Nakamura, Katsuta, JP;
Haruo Watanabe, Ibaraki, JP;
Masayuki Shigeta, Katsuta, JP;
Masakatsu Tanaka, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In an elevator, for controlling the upward and downward movement of a cage, a shoe is brought into and out of pressing contact with a drum or a disk of a brake by a combination of a spring and a hydraulic cylinder. The optimum braking force is determined in accordance with the inertial mass and the speed of the cage to be braked, and the fluid pressure is controlled to control the force of pressing of the shoe against the drum or the disk, so that the brake can always produce the optimum braking force. A controller for controlling the pressure of the hydraulic cylinder is operated by an emergency power source. The brake can be controlled with a high responsibility and its braking force can be controlled arbitrarily, and even in the event of a power failure, the brake can be operated by the emergency power source of a small-capacity. Therefore, in the normal condition, the cage can be held accurately in its stop position, and in the event of an emergency, the optimum braking force is produced in accordance with the load and the speed of the cage, and the shortest braking distance can be achieved with a small braking impact.