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:
May. 18, 2004
Filed:
Feb. 04, 2002
Applicant:
Inventors:
Assignee:
Leybold Vakuum GmbH, Cologne, DE;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B 1/704 ;
U.S. Cl.
CPC ...
F04B 1/704 ;
Abstract
A reciprocating piston drive mechanism, especially for a reciprocating piston vacuum pump, includes a cylinder ( ) embodied in a housing ( ). A piston ( ) is moved back and forth in the cylinder by an electromagnetic drive that has an electromagnet ( ) on the stator side and at least one permanent magnet ( ) on the piston side. In order to increase service life of said drive mechanism, permanent magnets ( ) are also provided on the stator side. The piston permanent magnet(s) ( ) and the stator permanent magnets ( ) are configured and disposed in such a way that the piston ( ) is magnetically biased to a substantially central axial position in the idle state.