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. 07, 1999
Filed:
Sep. 22, 1998
Wojciech B Kosmowski, San Juan Capistrano, CA (US);
Electro Scientific Industries, Inc., Portland, OR (US);
Abstract
A spindle capable of operation at 200,000 revolutions per minute (RPM) with a reciprocating shaft design to minimize the moving mass. The spindle has a ceramic spindle shaft to decrease the moving mass and increase the shaft stiffness for better dynamic stability. The spindle employs a built-in linear motor to provide direct drilling motion to move the shaft along the axis, and a permanent magnet DC brushless motor to rotate the spindle shaft. The linear motor is coupled to the shaft by a combination of an air bearing and a magnetic thrust bearing to reduce the size of the thrust area for better dynamic stability and reduction in stresses of material. A double gripping centrifugal chuck is mounted in the hollow ceramic shaft, and reduces drill bit runout.