Yarn tensioning apparatus for tufting machines capable of making pile fabrics with repeat patterns thereon of loops of varying lengths

摘要

1,105,909. Tufting machines. ELLISON TUFTING MACHINERY Ltd. 16 Jan.. 1967 [28 Jan., 1966], No. 3867/66. Heading D1G. A tufting machine for making a repeat pattern of yarn loops of varying lengths comprises a pattern member, a plurality of patternsensing means, a yarn-tensioner for each yarn in the machine, yarn-feeding means, and means for actuating a plurality of the tensioners, equal in number to the number of pattern repeats, by each sensing means. As shown, a central bar 10 is connected to upper and lower bars 12 and 13 respectively by spacing members 22. Mounted on the bars 12, 13 are a plurality of yarn-tensioner assemblies 11 equal in number to the number of yarns 23. Each of the latter passes over a face of bar 10 between a pair of pins 25, 26 projecting therefrom, and is fed to the respective needle by a pair of spaced-apart driven rollers (40), (41) at a speed corresponding to the length of a long tuft. Each assembly 11 comprises a cylinder 14 containing a piston rod 16 which carries at its outer end a piston 15a and at its inner end a brake shoe 15b, and which is biased outwardly by a spring 17. A T-junction 18, fitted to the outer end of cylinder 14, is con nected by a pipe 19 to a valve 32, and is interconnected by a pipe 20 with a plurality of assemblies 11 equal the number of pattern repeats. When valve 32 is opened by an associated solenoid 33 controlled by a patternsensing member, compressed air is supplied to the cylinders 14 of the inter-connected assemblies 11, whereby the associated brake shoes 15b engage and tension the associated yarns 23. thereby causing the latter to slip on the associated rollers (40). (41) for producing short tufts. In a modification, each tensioner assembly comprises a solenoid-operated valve. and the solenoids of a plurality of assemblies equal to the number of pattern repeats are energised simultaneously via a pattern-sensing member.