GB1123020A - Milking machines - Google Patents

Abstract

Milk in a pipe (2, Fig. 1, not shown), flows from a milk collecting member (1) in a milking machine past a preheated or precooled thermistor (4) thereby changing the temperature of the thermistor to a certain constant value, and when the flow of milk changes significantly the thermistor tends to assume its original temperature, the corresponding change in resistance being detected in a bridge circuit (Fig. 7, not shown) and used to turn off the machine. The bridge output is connected to a pair of transistors (15, 17) which operate a relay (19) when the milk flow drops. The thermistor is carried in a tube (5) which either protrudes into the pipe (2, Figs. 2, 3, not shown), or is situated adjacent the inner wall of the pipe (Figs. 4, 5, not shown), a heating coil (6) being arranged around the tube. Alternatively, the tube may be cooled by a jet of air from the milking room blown through a pipe (20, Fig. 6, not shown).