Yarn false twisting apparatus having improved thread-up capability

摘要

A yarn false twisting apparatus is disclosed which comprises two rotating twist imparting members, with a pressure applying member comprising a cylinder-piston assembly positioned to bias one member toward the other at the twisting zone. The apparatus includes an improved yarn thread-up capability which avoids breakage when the yarn is initially twisted, and which includes a pressurized air supply system for biasing the piston of the pressure applying member into operative contact with the adjacent twist imparting member, and control means for substantially reducing the pressure during yarn thread-up to thereby limit the nipping force applied to the yarn. In one embodiment, the air supply system includes a reservoir for cushioning the application of the pressure on the piston to thereby avoid the rapid application of a nipping force on the newly threaded yarn.