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:
Jun. 01, 2004
Filed:
Dec. 10, 2002
Yasushi Watanabe, Tokyo, JP;
Hiroshi Kiyosugi, Tokyo, JP;
Mikio Nakai, Tokyo, JP;
Yuki Ishida, Tokyo, JP;
Toshiaki Matsuo, Tokyo, JP;
Takashi Sekiya, Tokyo, JP;
Hitachi Building Systems Co., Ltd., Tokyo, JP;
Abstract
To accurately detect a trouble of a magnetic brake ( ) by eliminating any effect of a temperature of a location at which an elevator is installed, a temperature sensor ( ) is arranged to measure a temperature of the magnetic brake ( ). When an armature ( ) has been attracted responsive to a brake release command, the temperature of the magnetic brake is measured as a first temperature, and before the armature returns responsive to a brake actuation command, the temperature of the magnetic brake is measured as a second temperature. The first and second temperatures are compared with each other. When a result of the comparison between the first and second temperatures is determined to be greater than a predetermined value, the magnetic brake ( ) is determined to have been locked and hence, to have developed a trouble.