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. 21, 1989
Filed:
Nov. 09, 1987
Werner Oeggerli, Winterthur, CH;
Rieter Machine Works Ltd., Winterthur, CH;
Abstract
Friction spinning elements, in the form of drums or discs comprising perforated friction spinning bodies are subject to the requirement that, on the one hand, the entry section of each hole should be as small as possible, in order to prevent penetration of fibers wherever possible. On the other hand, the form of each hole in the longitudinal direction, as viewed in the airflow direction, should be as favorable as possible aerodynamically so that a hole acting as a nozzle generates the lowest possible air resistance. Further, the form of the hole viewed along its length should be selected such that dirt and dust or other contaminants which may penetrate into the hole do not remain caught therein. It has been established that in galvanically formed perforated bodies there is a tendency for each hole to become larger in section with increasing wall thickness, thus giving each hole a diffusor-like longitudinal section as viewed in the airflow direction. This advantage can be exploited in the use of the perforated body in a friction spinning process by arranging the fiber receiving surface of the body to be fabricated against the mold during the galvanic forming step whereby the narrowest section of the hole forms an opening edge at the fiber receiving surface.