| 摘要 |
An aerosol powder valve having a valve housing, a valve body, a valve stem, a gasket-retaining groove about the valve stem, and at least one valve orifice through the stem wall communicating with the groove and the stem discharge passage. The valve body below the groove has a plurality of vertical splines about its periphery with minimal area top surfaces of the splines abutting the gasket in the closed valve position. Circumferential spaces extend between the splines. The valve groove has a top annular surface, an intermediate neck portion with the one or more valve orifices, and a lower annular surface extending downwardly and outwardly at a sharp angle to the horizontal from the neck portion to the outer circumference of the valve body to join the valve body outer circumference at the level of the tops of the splines. The sharply angled annular lower groove surface may be frustoconical or preferably slightly convex, and has no horizontal or concave components for powder accumulation. The gasket seals the groove lower surface in the closed valve position and wipes the groove lower surface outwardly when the valve moves from open to closed position to cause any powder on the groove lower surface to fall into the circumferential spaces between the splines. The diameter of the valve body between the splines, at the level of the tops of the splines, is the same as the diameter of the valve stem above the groove. No powder build up can occur to interfere with the gasket sealing of the valve.
|
