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. 25, 1979
Filed:
Mar. 13, 1978
David L Barnett, Phoenix, AZ (US);
Three Phoenix Company, Phoenix, AZ (US);
Abstract
A method and apparatus for uniformly polishing the magnetic recording layer of a floppy disc by producing uniform relative velocities between the magnetic oxide material and the polishing medium across the floppy disc. The floppy disc is placed on a circular resilient pad disposed on a first spindle-mounted circular platen. A circular fibrous or abrasive polishing disc is disposed on a second spindle-mounted circular platen. The radius of the polishing disc is greater than the width of an annular region to be polished on the floppy disc, so that the relative velocities between points of the polishing disc and adjacent points of the floppy disc are uniform. Uniform polishing of the annular region results when the rotating polishing disc contacts the annular region of the rotating disc when the first and second platens are rotated in the same angular direction, at first and second predetermined angular velocities, respectively.