Apparatus for twisting yarn

1,103,387. Twist tubes; yarn guides. MONSANTO CO. 4 Oct., 1965 [7 Oct., 1964], No. 42032/65. Heading D1D. False-twisting apparatus comprises two pairs of synchronously belt-driven, similarly rotated, multiple friction-disc spools 4, 5, which twist two adjacent running yarns 9 in opposite directions preparatory to their combination in a balanced-torque stretch yarn. The spaced discs 12 in each pair of spools are staggered in relation to, and overlap or intermesh with, the discs of the other spool and the discs of each spool uniformly increase in diameter from each end to the centre, Fig. 3 (not shown) thereby defining a yarn trough having an arcuate convex bottom with which a yarn 9 is maintained in operative contact, or removed therefrom for stringing-up, by means of retractable guides. A manually operable guide assembly comprises two U-shaped members which may be independently or collectively pivoted to swing pairs of slotted, ceramic pin-carrying guides 27 mounted on arms 25, 26. In a toggle mechanism, the U-shaped members are moved in unison towards or away from an operative position (determined by limit stops 35 and adjustable screws 36) by linear movement of a handle 31 which slides a rod 30 within a stationary bore 32 and loosely carries a U-shaped spring 33 pivoted about pins mounted on each arm 25.