Improvements in or relating to automatic control systems

摘要

797,593. Automatic temperature control systems. KELVIN & HUGHES, Ltd. Feb. 16, 1956 [Feb. 18, 1955], No. 4927/55. Class 38 (4). [Also in Group XXXVII] In an automatic temperature control system for the barrel of a plaster extrusion machine, an unspecified device detects the temperature and controls a bimetallic relay which integrates the control signals and actuates either a heater or a cooler for the barrel as appropriate. The device 1 is stated to produce output pulses at terminals 3 and 4, the proportions of each cycle during which contacts 3 and 4 respectively are energized depending upon the barrel temperature. The pulses heat bimetallic strips 8, 10 either directly or by auxiliary heaters and the strips are joined by a bar 11 which tilts a single pole change-over mercury switch 12 if the strips 8, 10 are heated unequally. The switch 12 operates either an unspecified heater or an unspecified cooler as appropriate.