Two component external mix spray gun
AssigneeRansburg Corporation
InventorAlan H. Fritz
Life of this patent
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Abstract
A two component external mix spray gun having a pneumatically operated valve for controlling the injection of a catalyst into pattern shaping air passages in the gun. The catalyst is contacted with the atomized fluid externally to the spray gun. A trigger sequentially operates air and fluid valves to provide atomization air and pattern shaping air prior to opening the fluid valve. The pneumatic catalyst valve is responsive to an increase in the air pressure downstream from the air valve to inject the catalyst into the pattern shaping air prior to the opening of the fluid valve. The catalyst impinges on the atomized fluid eternally to the spray gun along with the pattern shaping air. The invention may be incorporated in either a hand held spray gun with a manual trigger or an automatic spray gun with a controller.
Claims10
In a two component external mix spray gun having a nozzle assembly, an air valve for controlling the flow of pattern shaping air to said nozzle assembly, a fluid valve for controlling the flow of fluid to said nozzle assembly and means for opening said air valve prior to opening said fluid valve when said spray gun is turned on and for closing said fluid valve prior to said air valve when said spray gun is turned off, the improvement comprising a fluid valve adapted to open in response to the presence of a pressurized flow of pattern shaping air to said nozzle assembly to inject catalyst into the flowing pattern shaping air in said spray gun.
A spray gun for atomizing a fluid and contacting the atomized fluid with a catalyst at a location external to said spray gun, said spray gun comprising a body, a nozzle assembly secured to said body, an air valve adapted for controlling the flow of atomization and pattern shaping air to said nozzle assembly, a fluid valve adapted for controlling the flow of fluid to said nozzle assembly, triggering means for opening said air valve prior to opening said fluid valve when said spray gun is turned on and for closing said fluid valve prior to said air valve when said spray gun is turned off, a normally closed pneumatically operated catalyst valve having a pressurized catalyst inlet port and an outlet port connected to a pattern shaping air passage in said spray gun, said catalyst valve having a pilot air port connected to respond to a pressurized flow of pattern shaping air from said trigger to said nozzle to inject catalyst into the flow of pattern shaping air in said air passage in response to an increase in air pressure downstream from said air valve when said air valve is opened.
A method for spraying a material having first and second components comprising the steps of:
- a) turning on a flow of pressurized air to a nozzle assembly, at least a portion of such flow of air shaping the pattern of atomized first material;
- b) opening a pneumatically operated second material valve in response to the flow of pressurized air to said nozzle assembly to inject second material into the flow of pattern shaping air;
- c) opening a first material valve after the flow of pressurized pattern shaping air is turned on to deliver first material to said nozzle assembly for atomization;
- and
- d) contacting the atomized first material with the flow of pattern shaping and second material.
Dependencies are inferred from the claim text.