Rotor for open=end spinning - has weft formation groove reduced for fine counts

摘要

Open-end spinning rotor, turned on a lathe, has the groove radius reduced by a cold forging process. The process is also claimed. Pref. the interior of the rotor (1) is conical, and at the bottom of the wall (2) is cut a circular groove (4) which accepts the fibres to be spun into a yarn. The groove has a radius (R) which requires to be only 0.1 mm. Initially the rotor is turned in the usual manner, and then an exterior radius (14) is created, so that the wall (15) is reduced in thickness. The radius is equivalent to the interior radius (4). Flat surfaces (8,9') are also created, and this rim is then tooled (10',11) up, above and below, with the bottom tool (10') at a slight angle, with compression applied to reduce the height (H) to a predetermined tolerance. In this manner the surfaces (8,9') extend outwards, and the wall (15) compacts, reducing the radius of the groove (4). ADVANTAGE - The smaller groove is suitable for yarn of finer counts. Turning tools are not accurate and fine enough to produce the groove required.