Apparatus for accurately filling beverage cans

摘要

Apparatus for filling beverage tanks comprising a liquid manifold and a gas manifold for counter-pressurizing the liquid as it fills the tank. Supply conduits connect the tank with the manifolds. The gas supply conduit contains a coupling device for connection to a fill-height tube on the container. This coupling device includes an optical sensor embodying a prism which reflects light from a light source when the tank has liquid below a predetermined level and directs light onto a photo-conductor. When the liquid reaches a predetermined upper level in the tank and is forced into the coupling device through the fill-height tube, the prism changes its reflective characteristics, and light passes through the prism without reflection. The change in reflective conditions is brought about by the liquid covering adjacent sides of the prism. The photo-conductor correspondingly changes an electrical signal that is utilized to operate a solenoid valve for shutting off the liquid to the tank.