Automatic milking systems

摘要

The suction-operated teat cups of an automatic milking system are associated with a multiple detector which yields a plurality of output signals individually indicative of (1) the milk flow rate after suction is applied to the teat cups, (2) the electrical conductivity of the flowing milk and (3) the temperature of the flow. The signal indicative of the flow rate is coupled to the input of a threshold-operated amplifier, which provides an output pulse to the input of a delay circuit when the signal indicative of the flow rate falls below a predetermined value. The retardation time of the delay circuit is chosen larger than the normal habitual start interval of the animal being milked, so that such delay circuit passes the output control pulse from the threshold device only if the diminution in flow is truly representative of a corresponding cessation of milk during steady state flow. The delayed control pulse is applied to a suction regulator for the teat cups to terminate the suction on the milk glands. The multiple detector is associated with an operational amplifier and with a temperature correction circuit to provide a corrected indication of the instantaneous electrical conductivity of the milk; when such conductivity falls outside a predetermined range, the suction on the teat cups is likewise terminated. The outputs of the delay circuit and the conductivity compartator are also coupled to separate portions of an alarm circuit.