Rotating head for crystal pulling systems for carrying out the czochralski process

US5766348A · kind A · utility

Assignee

• Leybold GmBH · DE

Inventors

• Winfried Schulmann · Kleinostheim, DE
• Franz Thimm · Alzenau, DE
• Helmut Kaiser · Wolfratshausen, DE

Key dates

• Filing date: Mar 24, 1997
• Grant date: Jun 16, 1998
• Expiry date: Mar 24, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T117/1072
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A rotating head (11) for crystal pulling systems (1) according to Czochralski has a reference platform (16) which is able to rotate around a vertical rotation axis (A--A) with a vertical feed-through opening (25) for a pulling cable (13) that can be wound up and a drive assembly (23) for driving a shaft (22). A winding drum (15) with a helical winding groove (29) for the pulling cable is located on this shaft in a fixed manner so it cannot rotate, but can be moved axially. In order to avoid abrasion and contamination and to accurately guide the cable (13), a helical guiding element (30) with the same pitch as the winding groove is located on the shaft (22) at a location remote from the vertical rotation axis (A--A). This guiding element is able to rotate with the shaft. The guiding element works together with a guiding nut (31) in such a way that the part of the cable (13) which faces tangentially away from the winding drum (15) is directly guided in the vertical rotation axis (A--A). Here, the helical guiding element (30) is designed as a guiding groove and the guiding nut (31) coopertes with the guiding groove by means of rotating balls (32).