GB957625A - Scutcher control mechanism - Google Patents

Abstract

957,625. Fibre preparation machines &c. COTTON, SILK & MAN-MADE FIBRES RESEARCH ASSOCIATION. July 16,1962 [July 14, 1961], No. 25506/61. Heading D1N. [Also in Division G3] The amount of fibrous material, e.g. cotton, fed to the beater 11 of a scutcher is determined by the speed of pedal roller 21 which is controlled in response to short term variations in the thickness of material at the pedal roller, while the datum about which such control is effected is varied by long term signals derived from variations in thickness of the web of material leaving the cages 12,13 at calender rollers 14... 16, the reference level about which the variations are measured being readily preset to desired values according to previous experience of the raw material. Adjacent the pedal roller is an arm 22 pivoted on a knife edge 23 and connected by a "piano link motion" 24 to a member 25 controlling the position of a belt 30 forming part of a conetype variable speed drive for the pedal roller, which is thus varied inversely as the thickness of material passing between the roller and the arm 22. The member 25 is pivoted about a pin attached to a lever 34 whose position is adjusted by a servomotor 32 in response to signals from a transducer 31 sensitive to the height of the calender rollers 14... 16. The signals may be continuously variable or indicative of upper and lower limits only. The transducer is carried on a pivoted arm whose free end bears on an adjustable platform, the height of which is preset by hand-turned gearing incorporating a counter; adjustment is made so that the counter registers a number found, by previous experiment, to result in a desired weight per unit length for a given raw material, on that particular scutcher (Fig. 2 not shown). There is preferably a transducer on each side of the top calender roller, and there may be means for switching-off the servomotor during doffing operations. The motor may also be fitted with limit switches.