Abstract: 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.

Abstract: An armored vehicle is provided with a gun mounted upon its top deck which gun is capable of rotation through 360.degree. C. about a vertical axis. The gun is also simultaneously elevatable through an angle of about 70.degree.. Located upon the deck are a plurality of barriers (some fixed and some conditional, e.g., opened hatches) which the gun must avoid during its rotational movement. The apparatus of the present invention includes a programmable read-only-memory which stores the location and height of each of the barriers on the deck. A computer continuously checks the position of the gun against the location of each of these barriers and provides signals which prevents the gun from moving into forbidden zones which include the locations of these barriers. As the gun approaches any of the barriers a signal is generated which causes the gun to be elevated from its normal path (if necessary) and lifted over the barrier.