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:
Jun. 15, 1993
Filed:
Dec. 23, 1991
Boris A Shtipelman, Rochester, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
A magnetic field bushing has a movable member and stationary rod. The stationary rod has high permeability strips of magnetic material forming a portion of the surface. The stationary rod further includes at least two sets of coils, the magnetic field resulting from application of a current to each coil being coupled to a strip. The movable member is configured to encircle substantially the stationary rod. The movable member has regions of high permeability magnetic material which are positioned on the movable member to complete a magnetic circuit with related magnetic strips. The magnetic circuits are completed through air gaps between the movable member regions and the stationary rod strips. The magnetic field in the air gaps results in a force between the movable member regions and the stationary rod strips. Forces are generated between the movable member and the stationary rod, the forces being selected to prevent contact between the movable member and the stationary rod. By using sensors which provide a signal determined by the distance between the movable and the stationary rod to control the current in the coils, the distance the members can be maintained even in the presence of external forces. This magnetic bushing has particular application to the actuator or read/write head of an optical storage system.