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. 05, 1991
Filed:
Feb. 21, 1991
Hitoshi Hattori, Yokohama, JP;
Hirotsugu Sakata, Chigasaki, JP;
Makoto Hayano, Tokyo, JP;
Masayuki Okuda, Kawasaki, JP;
Naoya Morozumi, Machida, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A piston is eccentrically arranged in a cylinder along its axial direction and can be rotated relative to the cylinder. Part of the piston is in contact with the cylinder's inner surface. First and second helical grooves are formed in the piston's outer surface and separated at its central portion, the pitches of the grooves being gradually increased from both end portions to the center portion of the piston. First and second blades are inserted in first and second grooves so as to be moved in and out of the grooves with the outer edges of the blades contacting the inner surface. The blades partition a space between the cylinder and the piston into a plurality of operation chambers with volumes corresponding to the gradual pitch increases.