US 4,968,525 AGranted

Method for production of friction spinning means

AssigneeRieter Machine Works, Ltd.

InventorsHerbert Stalder, Urs Keller, Emil Briner, Werner Oeggerli, Arthur Wurmli

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Abstract

There are formed at the wall of the friction spinning element bores or holes with a predeterminate bore diameter and a coating on their side facing a fiber feed duct, the coating extending over the bore edges into the bores or holes. Each bore or hole thus formed has a diameter at the bore or hole entrance or inlet which is smaller than the bore diameter of the related bore or hole. Each bore or hole has a cross-sectional area of less than 0.283 mm.sup.2, but amounting to at least 0.07 mm.sup.2. In this way, the undesirable penetration of fibers or fiber parts into the bores or holes is prevented as far as possible when air flows through the bores or holes at the side of the coating, while retaining a hole form or configuration which is favorable from the standpoint of airflow and blockage of the bores or holes.

Claims7

Dependent claims

A method for the production of a friction comprising the steps of:

forming throughflow holes at a friction spinning means for throughflow of air in a predeterminate airflow direction such that said throughflow holes of the friction spinning means possess a first predeterminate cross-sectional area;
each of said throughflow holes having a hole entrance;
deburring edges of the throughflow holes at least at the region of each hole entrance of said throughflow holes as viewed in said predeterminate airflow direction through said throughflow holes;
applying a coating to the friction spinning means at a side thereof where there are located said hole entrances in order to form a friction surface;
during the step of applying said coating to the friction spinning means at the side where there are located said hole entrances, narrowing each one of said throughflow holes in the region of its hole entrance due to the application of said coating and thereby forming in the region of said hole entrance a second predeterminate cross-sectional area for the throughflow of air and which second predeterminate cross-sectional area is smaller than said first predeterminate cross-sectional area of the remaining portion of said throughflow hole;
and
said second predeterminate cross-sectional area at the hole entrance of each throughflow hole being less than 0.196 mm.sup.2, but at least 0.07 mm.sup.2.

4 more elements

Dependencies are inferred from the claim text.