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. 14, 1985
Filed:
Mar. 30, 1984
Tsunenori Shibuya, Konan, JP;
Diesel Kiki Co., Ltd., Tokyo, JP;
Abstract
The communication between at least one of the pump inlets opening in at least two housing cavities and the suction chamber can be interrupted by a first valve means for prohibiting fluid compression in at least one of the housing cavities associated with the at least one pump inlet. At least one of the front and rear side blocks is formed with at least two passage means at locations corresponding to different ones of the cavities for introducing compressed fluid into back pressure chambers formed in the rotor. The communication between at least one of the passage means and the suction chamber can be interrupted by a second valve means. A control means actuates the second valve means so as to interrupt the communication between the at least one passage means and the suction chamber at the same time of establishment of the communication between the at least one pump inlet and the suction chamber, to thereby reduce the back pressure acting upon vanes moving in the above at least one housing cavity while the fluid compression in the same housing cavity is prohibited.