GB597979A - Improvements in or relating to the automatic control of the physical state of materials such as the dampness ofcloth - Google Patents

Abstract

597,979. Automatic control systems. FERRANTI, Ltd., TAYLOR, M. K., KNOWLES, A. D., and TOOTAL BROADHURST LEE CO., Ltd. Oct. 25, 1945, No. 28178. [Class 38 (iv)] The physical state, e.g. dampness of a material passing through a treatment zone is controlled by accelerating or decelerating its movement for periods of time proportional to a voltage representing the state, e.g. dampness and derived at predetermined regular distances along the material. The voltage representing dampness is derived, e.g. as described in Specification 597,978, [Group XXXVI], and is applied in opposite senses to valves 86, 96 to determine the rate of charging of condensers 87, 97 and thus the instants at which gas discharge tubes 91, 101 ignite. Each tube actuates a relay 92, 102 which actuate relays 94, 104 to provide holding circuits and to make and break the circuits of field windings of a reversible motor 120. The motor is thus operated in a direction depending on the sense of the voltage presenting the dampness and for a period depending on the magnitude of the voltage, whether positive or negative. Motor 120 rotates the brushes of motor 74 drawing the material 124 through the treatment zone, to accelerate or decelerate the movement of the material. The circuit of the discharge tubes 91, 101 is broken at 130 so that the correction is applied at predetermined regular distances along the material. Specification 591,147 also is referred to.