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. 21, 2011
Filed:
Dec. 10, 2007
Kozo Sasaki, Nagano-ken, JP;
Kozo Sasaki, Nagano-ken, JP;
Harmonic Drive Systems Inc., Tokyo, JP;
Abstract
The power-off electromagnetic brake () attracts an armature that is pressed by a spring force to a rotating member by a magnetic attraction force that is generated by energizing an exciting coil, and brake force that is acting on the rotating member is released. A voltage control circuit () continuously energizes the exciting coil for a fixed length of time and generates a considerable magnetic attraction force in order to attract the armature to a yoke when a brake power source () is switched on during brake release. After the armature has been attracted to the yoke, the voltage control circuit () intermittently energizes the exciting coil at a set cycle and a set on/off duty ratio to hold the armature in an attracted state to the yoke, thereby reducing power consumption and heat generation.