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. 26, 1990
Filed:
Jul. 31, 1989
Tatsuro Ishiyama, Yokohama, JP;
Takao Ushijima, Chigasaki, JP;
Toshiyuki Tabata, Yokohama, JP;
Toshihiko Aihara, Yokohama, JP;
Hajime Takeguchi, Yokohama, JP;
Bridgestone Corporation, both of, JP;
Nissan Motor Co., Ltd., both of, JP;
Abstract
A bush-type vibration damping device having an inner cylinder and an outer cylinder arranged in such a way that their axes extend in parallel with each other, and an elastic member is interposed between the inner and outer cylinders. A pressure receiving chamber, a first sub-liquid chamber and a second sub-liquid chamber are provided at one side of the inner cylinder. The first sub-liquid chamber has a not smaller resistance to expansion by pressure than the second sub-liquid chamber. The first and second sub-liquid chambers are connected to the pressure receiving liquid chamber through first and second communication passages, respectively. The second communication passage produces a not smaller resistance to flowing liquid than the first communication passage. Vibration of a comparatively low frequency and large amplitude is adsorbed by the flow resistance encountered by a liquid displaced through the second communication passage, while vibration of a comparatively high frequency and small amplitude causes a resonance of the liquid in the first passage so as to limit increase in the dynamic spring constant.