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.

Abstract: An improved nozzle assembly for an HVLP paint spray gun. The nozzle assembly includes at least an air cap and a fluid tip, and preferably also includes a baffle for uniformly distributing air flow through the nozzle assembly. The fluid tip has a conical front end which terminates at a fluid discharge orifice adjacent a vertex. The fluid tip is positioned to extend to and to be in axial alignment with an opening in the air cap. The fluid discharge orifice is located at substantially the front face of the opening. The fluid tip and the air cap form an annular air discharge opening. The conical front end of the fluid tip has a vertex angle of from 60.degree. to 90.degree., and preferably about 60.degree.. The air cap has a thin wall surface surrounding the opening and has an annular interior surface surrounding the opening in the shape of a frustum of a right circular cone having a vertex angle of from 100.degree. to 150.degree. and preferably of from about 124.degree. to about 128.degree..

Abstract: A replaceable baffle for dropping high pressure air to low pressure air for atomization and for pattern shaping in a high volume low pressure (HVLP) air paint spray gun. The baffle has a first plurality of orifices for distributing and dropping the air pressure to a low pressure for atomization and has orifices arranged in two stages for dropping the air pressure to a low pressure for pattern shaping. The baffle may be replaced with a baffle having different sized orifices to permit use of different air cap and/or fluid tip designs on the spray gun when applying paints having different flow properties.

Abstract: An improved high volume low pressure air (HVLP) operated paint spray gun of the type having adjustable fan air and suitable for operation from a high pressure air source. The high pressure air passes from a high pressure chamber through first or second parallel calibrated orifices to supply both low pressure atomization air and low pressure fan air for controlling the shape of the spray pattern. In one embodiment, both orifices supply air to a low pressure chamber which in turn supplies both atomization air and fan air. A fan air control ring adjusts the flow of low pressure air to fan jet orifices. Rotating the fan air control ring controls both air flow through the second orifice to the low pressure chamber and air flow from the low pressure chamber to the fan jet orifices. In a second embodiment, one orifice supplies only low pressure atomization air and the other orifice supplies only low pressure fan air. A valve adjusts the flow of fan air.