GB734078A - Method of and means for automatically controlling the controlling the output of a carding engine involving the condenser system - Google Patents

Abstract

734,078. Carding-engines; testing and measuring slivers &c. WOOL INDUSTRIES RESEARCH ASSOCIATION and LIVERSIDGE, C. Sept. 15, 1952 (Sept. 14, 1951], No. 21598/51. Classes 120(1) and 120(3). [Also in Group XXXV] In a method of automatically controlling the production of slubbings or their equivalent by a carding engine under a condenser system, variations in the weight per unit area of the web at a point within the machine are measured and/or recorded by a device, which may include the mechanism described in Specification 727,403, [Group XXXVIII], (see Group XXXV), the output of which regulates the speed of the doffer relative to that of the swift or its equivalent so as to maintain the weight per unit area of the web at a desired value. The device may project through or on the web some form of non- varying radiation e.g. a beam of light, ultrasonic energy, Beta rays or sound waves, to assess variations in web thickness and hence weight per unit area, or it may be a mechanical feeler gauging the thickness directly. As shown a running web 2 passes between one or groups of photo-electric cells 4 and 7 so placed that the latter receives light from the same area of the source 1 as cell(s) 4 receives it after it passes through the web 2 : variations in the web cause changes in the light falling on cell(s) 4 and hence the current therethrough : the currents in the cells 4 and 7, amplified in amplifier 9 if required, are compared differentially and a resultant signal proportional to a deviation in the web from a desired value fed to a recorder 10 and also to a regulator 11 in a variable ratio transmission unit 12 which interrupts the normal mechanical linkage 15-17 through which by belt transmission the swift 16 drives the doffer 5 and condenser 6 via wheel 14, or the linkage 15 may be replaced by a separate local power unit such as an electric motor still driving the unit 12, to effect the required correction : the setting of the unit 12 is transmitted by a " closed-loop " servo system 13 comprising a self-synchronous transmitter and motor or to a torque balance device as described in Specification 589,423, [Group XXXVIII], where it is compared with the output or time or amplitude function thereof ; any error due to change in the weight per unit area of the web exceeding predetermined limits causes a relay-operated electric motor to cancel the error. In modifications (not illustrated) the error signal, instead of being fed to recorder 10, is made to adjust the amount of light falling on cell(s) 7 in such manner that the signal tends to reduce to zero and the displacement of the light adjusting device is recorded and provides the measure of the necessary adjustment of doffer speed : also the cell(s) 7, by arrangement of mirrors and switching devices, may replace cell(s) 4 as well as effecting reference and balancing functions.