GB740082A - - Google Patents

Abstract

740,082. Fibre drafting apparatus. SACOLOWELL SHOPS. June 6, 1952 [June 11, 1951], No. 14382/52. Class 120 (2). Drafting mechanism of the kind in which an upper roller rests on a lower apron as it passes between a supporting roller and a bar has a positively driven apron driving roller outside the apron loop and partly encircled by the apron immediately in advance of the rearward portion of the loop to form a driving nip with the supporting roller. The apron 12 is tensioned by a roller 22 from which it passes to the driving roller 20 and round the supporting roller 14 to the bar 16. Upper roller 18 is pressed on to the apron 12 by a leafspring 48 that is secured to a slide 30 by one end and has its other end pressed upon the outer race of a ball bearing applied to an end of the roller 18, another spring 48 (not shown), pressing upon a bearing at its other end. Under normal conditions the springs 48 press the bearings of the roller 18 against the support for the bar 16 and the bearings of the roller 14 so that a clamping nip is not provided between the rollers 14, 18 and single-zone drafting between rollers 3, 4 and 5, 6 is effected. If desired, however, a clainping nip may be arranged so that draft takes place between the rollers 3, 4 and 14, 18. Pressure from the springs 48 causes a firm nip between the roller 14 and the driving roller 20. The roller 20 extends throughout the length of the machine, but the rollers 14, 18 are arranged in short sections, preferably to operate upon four slivers. Each section is positively driven and the sections may readily be removed from the machine in association with the corresponding apron bars and aprons. A peripheral speed 3 to 6 per cent greater than the speed of roller 14 is preferred for the roller 18, the bosses 19 of which may be of a resilient composition, such as natural or synthetic rubber of a durometer hardness of 50 to 100, or may be of smooth steel, or may be formed as porcupine rollers. Three slides 28, 30, 32 are mounted to be adjustable along a track 25 and carry the roller 6, rollers 14, 20 and the apron bar 16. An arm 15 loaded by a spring 17 applies pressure to the rollers 3, 5 through a fulcrum 11 and a weighting bar 7. The bearings of the rollers 14, 18 may be of an antifriction type, or may be of nylon or sintered metal. Specifications 524,666, 663,573, 668,880 and 672,728 are referred to.