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:
Dec. 27, 1988
Filed:
Mar. 30, 1987
Nobuaki Ishihara, Kariya, JP;
Toshihiro Takei, Okazaki, JP;
Yoshiyuki Hattori, Toyoake, JP;
Koji Okazaki, Kariya, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
A rotary piston vacuum pump has a rotor eccentrically disposed in a cylinder and mounted therein for revolution in rolling contact with the cylindrical inner peripheral surface of the cylinder so that a crescent-shaped space is defined between the rotor and the cylinder and moved around the axis of the cylinder. A vane is radially reciprocally mounted in a vane chamber having an inner end open to the cylindrical inner peripheral surface of the cylinder. The vane has an inner end in sliding contact with the outer peripheral surface of the rotor to divide the crescent-shaped space into a suction chamber in communication with a suction port and a discharge port to be communicated with a discharge port having an inner end open in a wall of an outer part of the vane chamber. The rate of communication between the discharge port and the discharge chamber through the outer vane chamber part is varied by the reciprocal movement of the vane so that the communication is interrupted at least when the point of contact between the rotor and the cylinder inner peripheral surface reaches the vane.