Method and apparatus for mixing and dispensing foam with injected low pressure gas

A foam dispensing apparatus for mixing a plurality of foam components into an expanded foam and dispensing the mixed foam components, comprising:

• a body portion having a handle assembly and a carrier assembly mounted on said handle assembly;
• a cartridge assembly including a mix chamber having a longitudinal bore and an aftermix chamber in communication with said mix chamber;
• means for supplying the plurality of foam components to said longitudinal bore of said mix chamber, wherein said means for supplying includes a plurality of inlets in said cartridge assembly through which the plurality of foam components enter said mix chamber and a plurality of fluid passageways in said carrier assembly which are in communication with said plurality of inlets, said plurality of fluid passageways adapted to receive the plurality of foam components;
• means for controlling the flow of the plurality of foam components into said mix chamber, wherein said means for controlling includes a valve rod which slides in said longitudinal bore of said mix chamber and means for moving said valve rod between an operative position in which said valve rod permits the plurality of foam components to enter said mix chamber and an inoperative position in which said valve rod prohibits the plurality of foam components form entering said mix chamber;
• and
• means for injecting a pressurized gas into said aftermix chamber during the flow of the plurality of foam components into said mix chamber to aid in the mixing of the plurality of foam components and to provide an improved spray pattern of foam, wherein said means for injecting includes an injection port in said aftermix chamber in communication with a source of pressurized gas.

A method of mixing a plurality of foam components into a foam and dispensing a foam spray from a foam dispensing apparatus, each of the plurality of foam components being pressurized, comprising the steps of:

• introducing each of the plurality of foam components into a mix chamber of the foam dispensing apparatus;
• mixing the plurality of foam components in the mix chamber to form a foam;
• introducing pressurized gas at a location downstream of the introduction of the foam components into the mix chamber and while the foam components are introduced into the mix chamber to provide additional mixing of the foam;
• and
• dispensing a foam spray from the foam dispensing apparatus.