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:
Feb. 26, 1985
Filed:
Oct. 19, 1982
Yutaka Ishizuka, Saitama, JP;
Diesel Kiki Co., Ltd., Tokyo, JP;
Abstract
A portion of the endless camming surface of the pump housing, which performs one cycle of suction, compression, and discharge of fluid in cooperation with the vanes and the rotor, includes an increasing radius portion and first through fourth decreasing radius portions successively arranged in the advancing direction of the vanes. These camming surface portions have such cam profiles that with movement of each vane, the amount of protrusion of the vane gradually increases along the increasing radius portion, and gradually decreases along the decreasing radius portions, the receding speed of the vane gradually increasing along the first and third decreasing radius portions, and gradually decreasing along the second and fourth decreasing radius portions. The cam profiles may preferably vary along quadratic curves. Preferably, the above one cycle performing portion further includes one or two constant radius portions located between the above five portions, along which the amount of protrusion of each vane is kept substantially constant with movement of the vane.