Sandblasting nozzle and control valve assembly

#The present invention relates, in general, to a nozzle and control valve assembly for pressurized abrasive cleaning systems and the like, and more particularly to a control valve structure immediately adjoining and connected to a sandblasting nozzle in pressurized sandblasting cleaning system whereby valve control of the sandblasting steam is under control of the workman at the nozzle location adjacent the surface being sandblasted.

#Heretofore, many sandblasting systems and air-water-chemical or other abrasive media systems have been devised wherein some kind of manually controllable valve structure in incorporated in the system to provide operator control of the sandblasting stream or abrasive material stream to be discharged from the associated hose and nozzle system leading from a compressor to permit operator control of the abrasive cleaning stream. However, the control valve structure has most frequently been located at the source of the compressed air and sand or other abrasive material, rather than at the nozzle or work location, because of the severe disintegration and wearing which has been encountered where attempts have been made to provide the control valve at the nozzle location or discharge stream end. Because of the highly abrasive nature of the pressurized cleaning stream being conveyed through the hose and nozzle, and therefore the severe abrasion wear on the components of valve mechanisms exposed to the abrasive stream near the nozzle end of the hose and nozzle parts of the system, it has been considered expedient to locate the control valve structure back at the upstream or source end of the hose adjacent the source of the sand and pressurized air and/or water to provide an arrangement which would have an acceptable useful work life.

#I have heretofore developed a control valve assembly for use with a sandblasting nozzle, as disclosed in my U.S. Pat. No. 4,460,011 granted July 17, 1984, wherein the control valve is constructed in such manner and with such materials as to be sufficiently wear resistant to the highly abrasive materials flowing in the sandblasting or abrasive pressurized stream to provide acceptably useful life and still allow control of the sandblasting or pressurized abrasive stream at the nozzle location immediately adjacent the surface being abrasively cleaned. Such prior control valve of my earlier patent was constructed in such a manner to allow higher volumes of air and sand or other abrasive media to pass through the valve with less wear than previous sandblasting or similar valve mechanisms located near the discharge end of sandblasting hose systems, and wherein the valve structure can be used with many different types of pressurized abrasive media systems because of its high abrasion resistance and particular valve design.

#FIG. 1 is a top plan view of an intercoupled control valve and nozzle assembly for a sandblasting or pressurized abrasive media surface abrasion system embodying the present invention;

#FIG. 2 is a side elevation view thereof;

#FIG. 3 is an end elevational view thereof as seen from the left of FIG. 2;

#Referring to the drawings, wherein like reference characters designate corresponding parts throughout the several figures, there is shown in FIGS. 1-4 the control valve assembly of the present invention joined to the immediately associated parts of a sandblasting abrasive cleaning system or similar air-water-chemical or abrasive media cleaning system, wherein the control valve assembly is generally indicated by the reference character 10 and comprises valve case or housing 11 joined at one end to a pipe or sandblast hose 12 leading to pressurized supply source for the air and sand or air/water and other abrasive media and joined at the other end to a typical sandblast nozzle or discharge pipe 13 which in the illustrated embodiment has a ribber exterior and is threaded at the end to be joined to the valve assembly case 11 to thread into the adjacent end portion of the valve case 11. In the illustrated embodiment, the valve case or housing member 11 includes end walls 14, 15 having a pair of mounting flanges 14a, 15a, for securing the valve housing to the supply pipe or hose 12 and to the nozzle 13. Between these two end walls 14 and 15 is the intermediate valve chamber portion 16 defining a lower valve chamber 17a a communicating at its rear end with the supply pipe 12 and communicating at its other end through an internally threaded port 15p in the end wall 15 forming a valve seat supporting channel for the valve seat member 20. The valve case 11 has an upwardly extending top portion enclosing an upwardly extending top well formation 17b adjoining the valve chamber 17a for housing the mechanism for operating the valve member and portions of the valve member when in the open position. As shown in FIGS. 1-3, the valve housing or case 11 is closed at the top by a valve cover member indicated at 11c secured to the flange 11f of the valve case or housing 11 by bolt and nut fasteners indicated at 11g.

#The valve seat, indicated by reference character 20, is an annular cylindrical member, formed for example of polyurethane, provided if desired with tungsten carbide ribs (not shown), in the general shape of an annular cylinder sized to seat in and be restrained in the threaded part 15p of the case or housing 11, and having a beveled or truncated conical surface 20a to define the actual seat against which the valve ember presses to close the valve.

#To protect the surfaces of the valve case or housing member 11 bounding the intermediate valve chamber 17a against the corrosive and abrading effects of the abrading medium, these surfaces are covered by a formed-in-place or poured-in-place valve chamber liner, for example of polyurethane or gum rubber, indicated by the reference character 22, which assumes an upwardly facing or opening "U" shaped configuration corresponding to that of the inwardly bounding surfaces of the valve chamber 17a. A unique pivot valve member, indicated by the reference character 24, is housed in the valve chamber 17, and comprises a generally cylindrical, beveled valve head portion 24a having a truncated conical surface portion 24a' which conforms to and tightly seats against the correspondingly shaped valve contact seat portion 20a of the valve seat member 20. Extending rearwardly at an upwardly inclined angle relative to the center axis of the head portion 24a when the valve member is viewed in closed position, is an elongated stem portion 24b, which is of substantially inverted "T" shaped cross-section defining a wider bottom portion of flange like configuration 24c having a convex bottom surface 24d whose curvature corresponds substantially to that of the projection of the perimeter of the head portion 24a along the longitudinal axis of the stem portion, and which defines a rising vertical center rib portion 24e terminating rearwardly in an elongated or rearwardly extending tail member 24f. A concave, almost half-cylindrical cutout 24i is provided in the upper surface of the vertical center rib portion 24e immediately rearwardly of the enlarged head portion 24a shaped to receive portions of the linkage yoke or fork member 25 and of the operating shaft 26 therefor when the pivot valve member 24 is in the raised or retracted open position shown in FIG. 6. In these respects, the valve member 24 is similar to the valve member shown and described in my earlier U.S. Pat. No. 4,460,011.