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. 15, 2000
Filed:
Feb. 04, 1998
Norio Kimura, Fujisawa, JP;
Toshiya Takeuchi, Tokyo, JP;
Ebara Corporation, Tokyo, JP;
Abstract
A workpiece holding device enables stable polishing to be performed without sacrificing the structural strength of a top ring or the space necessary for machining a through hole or implanting engaging pins while allowing close contact to be made between a workpiece to a polishing cloth on a polishing tool. The top ring includes a top ring member having a holder plate for holding the workpiece on a front surface and a cover plate attached to a back surface of the holder plate by engaging a depression section formed on a back surface of the holder plate with a protrusion section formed on a front surface of the cover plate. A curved surface bearing unit provided between an end portion of a drive shaft and a back surface of the cover plate couples the drive shaft and the top ring member while permitting motion of the top ring member relative to the polishing tool. At least a portion of the curved surface bearing unit is positioned within the depression section.