GB889969A - Improvements in or relating to apparatus for detecting and correcting departures from standard thickness or weight per unit length in textile slivers - Google Patents

Abstract

889,969. Textile drafting mechanism. BRITISH JUTE TRADE RESEARCH ASSOCIATION. June 27, 1958 [April 3, 1957], No. 10811/57. Class 120(2) Mechanism for apparatus for detecting, and after an interval, correcting for departures from a standard in the thickness of a textile sliver undergoing drafting, comprises a rotatable frame around which are slidably mounted a number of rods, means for clamping those rods against longitudinal movement around the major portion of the periphery of the frame other than at a predetermined zone, and a feeler constrained to move in a direction parallel to the axes of the rods such that a surface contacts each rod in turn and follows the profile formed by the displacement of the rods. In Fig. 1, rods 4 are mounted in V-slots in a drum or pair of spaced discs, a large number of rods being employed to increase the sensitivity of the device. As the drum &c. rotates, the rods are moved along the slots to a uniform position determined by the setting of a zeroising cam 5. Their position is then adjusted by a cam 6 according to the thickness of sliver lying between detecting rollers and, after an interval, they correspondingly displace a feeler 8, whereby, through a parallel linkage and a sliding connection, oil relays are operated which control the drive to the drafting rollers. The mounting of the feeler is such that the length of the interval can be accurately adjusted. The feeler is of V-section, the angle of the V being not greater than twice that between the rod axis and the gradient of the rod-ends resulting from the probable maximum displacement of the rods. Between the cams 5 and 6, the rods are free to move in their slots, although they may be lightly retained by a guide or sheath; around the remainder of the drum circumference they are clamped by one of the following: a tensioned belt; an endless wire &c. twisted several times around the drum and a grooved pulley the diameter of the pulley, the position of the pulley above the drum, and the angle at which the axis of the pulley is skewed relatively to that of the drum being suitably chosen; a band surrounded by a roller chain constrained over part of its circumference by a clamp; the arrangement shown in Fig. 5. Here the drum consists of flanges 20 and a core 21 all of mild steel the latter being surrounded by an energizing-coil 24 which draws the rods into slots 23 in the flanges except where its effect is off-set when an air passage 25 in each slot registers with passages 28 in blocks 27 in communication with air under pressure.