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:
May. 27, 1980
Filed:
Sep. 13, 1978
Nobuaki Date, Kawasaki, JP;
Hiroshi Aizawa, Kawasaki, JP;
Masanori Uchidoi, Yokohama, JP;
Masami Shimizu, Tokyo, JP;
Teiji Hashimoto, Kawasaki, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
In a focal plane shutter having two curtains which unwind from shafts after being released, the shaft controls a master gear, causing a keying pin on the latter to activate braking action on the curtain at a time interval near the terminal end of running-down movement of the curtain, as a pair of heavy expanding frictional shoes are driven to rotate at accelerated speeds and pressed against the internal surface of a fixed drum by a centrifugal force. During the shutter cocking operation, the key is taken out of connection with the brake so that the driving torque of the film winding shaft is correspondingly decreased.