Load detecting system for automatic storage apparatus

Abstract From the Canadian patent

Apparatus for detecting a load within a preselected bin of an automatic storage rack has a transducer for directing an ultrasonic beam into the bin and for detecting an echo reflected from a load struck by the beam; a digital counter adapted to generate plural bit binary pulses which is started upon initial transmission of the ultrasonic beam; and a programmable memory coupled to the counter and programmed to generate a given bin-full output signal upon initial transmission of the beam and to subsequently generate the opposite binary bin-empty output signal if no echo has been detected when the pulses from the counter stored in the memory indicate that sufficient time has elapsed after …