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. 14, 1989
Filed:
Jan. 26, 1988
Wilhelm Strasser, Bergisch Gladbach, DE;
Axel Veit, Pulheim, DE;
Leybold Aktiengesellschaft, Cologne, DE;
Abstract
A throttle valve with a separate flange, usable with a vacuum pump defining an inlet opening, and a controllable throttle assembly for varying a flow passage cross section of the inlet opening. The throttle assembly is disposed in the inlet opening and has a plurality of slats rotatable about respective longitudinal axes for varying their inclination and an actuating rod for turning the slats. The flange has a throughgoing bore through which the actuating rod passes. The slats have a substantially constant width and their longitudinal axes are oriented parallel to one another. The slats form a first and a second slat group, and a linkage connects the slats with one another for turning the slats of the first slat group and the slats of the second slat group in opposite directions. A chamber is situated externally of the inlet opening and communicates with the throughgoing bore. A pivotal lever articulated to the actuating rod is situated in the chamber and projects outwardly therefrom. There is further provided a swingable bellows supported in the chamber and surrounding the pivotal lever for providing an airtight separation of at least one part of the pivotal lever from the chamber.