Foam dispensing apparatus

A method of converting a plurality of foam components into an expanded foam in a dispenser including a barrel having a plurality of passages formed therein which communicate with a center plug, the center plug having discrete passages for each of said fluid components, a mixing chamber connected to the center plug, the mixing chamber being located outside the barrel, a nozzle connected to the mixing chamber and having a bore therethrough, one end of the bore communicates with the mixing chamber while the other end provides an opening for discharging the expanded foam from the dispenser, a tube for carrying each foam component to the dispenser, each such tube having a corresponding tube for carrying a compressed gas to the dispenser, a rotary valve component for each pair of foam component and compressed gas tubes, each such valve having a single passageway formed therethrough with an inlet and an outlet, each valve being mounted for movement on the barrel so that the inlet of each valve is rotatable between positions nearly coterminous with the outlets of the foam component tubes and the compressed gas tubes, and the outlet of the valve remains in communication with the passageway of the center plug, and means for moving all valves in unison between communication with the foam component carrying tubes and communication with the compressed gas carrying tubes, the method comprising the steps of admitting the foam components into the center plug through the valves, passing the foam components through the discrete passageways in the center plug into the mixing chamber, reacting the components in the mixing chamber to form expanded foam, and discharging the expanded foam from the dispenser so that after the foam components have been mixed and the expanded foam discharged from the dispenser, the dispenser can be cleaned with the compressed gas from the point where the foam components enter the dispenser to the point where the foam components enter the mixing chamber.