Spray head

Claim 1

A nozzle assembly for spraying a fluid material which comprises a tubular body having a coupling at one end for attachment to a fluid material supply means, said body having an axial bore which is divided into sections of different cross sectional diameter, a section of large diameter being at the discharge end of the bore which is remote from the coupling and which forms a chamber for receiving a generally spherical spray tip holder and associated bearing forming means for mounting said tip holder for rotation therein, said tip holder having a diametrical bore with an enlarged portion at one end forming a recess for seating therein a spray tip, a readily removable cap mounted on the discharge forming end of said axial bore for retaining said tip holder in said chamber, said cap having a center spray discharge opening of smaller diameter than the diameter of the tip holder and having a narrow inner annular face mating with the curved surface of the tip holder so as to form a bearing for the tip holder, and an inner bearing and sealing assembly in said chamber for cooperation with said cap in supporting said tip holder so that it may be rotated between a spraying position where the bore thereof is axially aligned with the bore in the body to permit passage of the fluid material for spraying and another position where the flow of the fluid material is in the opposite direction through the tip for clearing the tip, said inner bearing and sealing assembly comprising a bearing member with a relatively small axial bore, positioned with a cup shaped end, disposed in said end chamber and forming a seat for said tip holder with bearing and sealing areas mating with the curved surface of said tip holder and a stem forming end portion of substantially lesser cross sectional diameter than the diameter of said cup shaped end portion and extending into a section of the bore of the body which adjoins said end chamber forming section and which is of substantially lesser diameter than said end chamber, said cup shaped portion of said bearing member having an outside diameter substantially greater than the outside diameter of said stem portion with an axially facing shoulder formation between said portions and a sealing gasket between said shoulder formation and an internal confronting shoulder formation separating said body end chamber forming bore section and the adjoining section of the bore of the nozzle body into which said stem portion extends which sealing gasket is precompressed when installed so as to hold the inner and outer bearing surfaces in engagement with the mating surface of said tip holder, said stem portion having an outside diameter somewhat smaller than the diameter of the body bore section into which it extends and a seal forming element of resilient material associated with said stem portion for sealing between an outside face of said stem portion and the confronting inside face of said lesser diameter bore section and arranged so as to permit a minimum of force in an axial direction on the bearing member by the fluid material.