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:
Apr. 18, 1989
Filed:
Feb. 29, 1988
Hans Amrath, Viersen, DE;
Zoltan Szocs, Bonn, DE;
Leybold Aktiengesellschaft, Cologne, DE;
Abstract
A vacuum pump has a housing, a pump shaft having a terminal shaft portion, a bearing member mounted in the housing and supporting the pump shaft and a rotor affixed to the pump shaft. The housing has a housing wall forming a side chamber with the bearing member. The terminal shaft portion projects through the bearing member into the side chamber. There is further provided a device for measuring the rpm of the rotor. The device comprises an inductive sensor held in the housing wall and a ferromagnetic member mounted on the terminal shaft portion for rotation in unison therewith. The ferromagnetic member induces electric pulses in the inductive sensor at a rate proprotionate to the rpm of the rotor. A non-magnetic partition separates the inductive sensor from the side chamber.