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:
Nov. 24, 1992
Filed:
Jun. 03, 1991
Richard C Dumler, Breckenridge, MI (US);
Elden E Ruhlig, Mt. Pleasant, MI (US);
Matthew J Stavely, Saginaw, MI (US);
Hemlock Semiconductor Corporation, Hemlock, MI (US);
Abstract
The present invention is a device for separating semiconductor grade silicon pieces into desired size ranges, while minimizing contact contamination of the separated pieces. The device employs a rotatable cylindrical screen, with contact surfaces of semiconductor grade silicon. In a preferred embodiment, the cylindrical screen consists of parallel rods of semiconductor grade silicon separated by semiconductor grade silicon, internal, spacers. In addition, external spacers of semiconductor grade silicon are arranged along the length of the parallel rods to further define the exclusion characteristics of the cylindrical screen.