Flanged swirl valve with relieved elastomer seal

Abstract

An airless spray paint gun having an improved swirl valve which is less susceptible to erosion and reduces the amount of sputtering in the paint spray. The spray paint gun includes a gun assembly including a handle, a motor, and a switch for controlling the motor. A pump subassembly mounted to the gun assembly includes a pumping chamber having a discharge end with a beveled seat, a piston mounted within a pump housing and driven by the motor for pumping paint from the container through the discharge end of the pumping chamber, and a swirl valve mounted within the discharge end of the pumping housing. The swirl valve includes a valve body having first and second opposite sides, three paint swirl apertures extending through the valve body between the first and second opposite sides, an annular flange that radially projects from the valve body between the first and second sides, and a beveled seat-engaging surface on the second side of the valve body having an elastomeric material thereon co-molded with the valve body. The elastomeric material is softer than the material of the valve body. The flange is interposed between a spray tip and the discharge end of the pumping chamber and contacts the discharge end when the spray tip is mounted to the pump housing. The flange thus prevents excessive axial forces from being applied to the swirl valve, and thereby prevents cold flow and the plastic deformation of the elastomeric material while allowing the elastic deformation of the elastomeric material on the swirl valve. The elastomeric material is relieved in a cavity surrounding each swirl aperture to prevent migration of the elastomeric material into the swirl apertures.