Abstract: A hand-held, chuck-type part holder provides holding means for a machine part. The hand-held part holder may be secondary holding means for a part which itself is then inserted into a primary machine clamp. The chuck uses standard replaceable collets which may be easily interchanged for different size parts. The collet is actuated by a rod which is moved in turn by an air cylinder which is supported by a handle. The part-gripping collet may be actuated by a tilt switch which provides the automatic clamping action of the collet as the operator turns the holder to the vertical position before inserting or removing a part from the end of the collet. Additionally, a fixture mounted to the bed of the processing machine may be used which guides the part holder into alignment with the primary clamp as it is inserted. The fixture includes pivot and slide means which both support and direct the movement of the part holder.

Abstract: A development is provided for monitoring twist on yarn being perferably friction twisted and for automatically adjusting the amount of twist being imparted to the yarn to compensate for a deviation in the amount of twist from that desired. The adjustment and monitoring may be effected on a position-to-position basis. Particularly novel monitoring developments are provided.

Abstract: An improved friction twisting head is provided for imparting false twist to yarn passing therethrough. The apparatus is adapted for use on existing machines. A modified form of the apparatus is adapted for allowing a running adjustment of the amount of twist being placed into the yarn as the yarn passes therethrough. On a multiple-station arrangement, this adjustment is provided at each station to allow independent control of the twist being introduced at each station.