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. 24, 1992
Filed:
Apr. 30, 1990
Kazuyoshi Ohshima, Tokyo, JP;
Sugatsune Industrial Co., Ltd., Tokyo, JP;
Abstract
According to the invention, there is provided a damper for a flapdoor that does not show any damping effect when its movable shaft of the damper is rotated with the door in one sense whereas it effectively damps the rotary movement of the flapdoor when the movable shaft is rotated with the door in the other sense, wherein a one-way clutch for engaging or disengaging the movable shaft with a movable member depending on the sense of rotation of the movable shaft to cause a viscous shearing drag in the viscous fluid contained in the damper and a power source constitute so many integral parts of a coil spring. A damper for a flapdoor having such an arrangement can have a simplified configuration as compared with a damper provided with a separate coil spring as power source and a separate one-way clutch and therefore can be realized with reduced dimensions. Moreover, since such a one-way clutch can be prepared from a coil spring without requiring any additional processes and by simply engaging a portion of the coil spring with the movable member, the rest of the coil spring functioning as power source, the damper can be realized at a significantly reduced cost.