Automatic water shutoff system

摘要

An automatic water shutoff system for filling water tanks on concrete mixer trucks, including a nozzle assembly attached to a water hose. The nozzle assembly includes a first elongated tube surrounded by a second shorter tube. A flange closes the proximal end of the second tube and forms an air chamber between the first and second tubes. The end of the first tube closest to the flange forms a water inlet nipple. An air pressure sensing tap is formed by a small tube passing through the flange. One end of the tap communicates with the air chamber and a second end of the tap is attachable to an air pressure sensing tube, operatively coupled to a pressure switch. When pressure in the air chamber reaches a predetermined, water tank full level, the pressure switch causes the pump or valve to turn off the flow of water into the tank.