Patent ID: 8220724

Claim:
A nozzle assembly for rotatably spraying high pressure fluid against an object to be cleaned, the assembly comprising: an inlet nut; a hollow cylindrical housing body; a hollow tubular shaft member coaxially carried within the housing body and captured between the inlet nut and the housing body; a spray head attached to one of the shaft member and the housing body for rotation therewith; one of the inlet nut and the spray head having a stem forming an inlet bearing area on which an inlet end of the shaft member is supported for relative rotation between the stem and the shaft member, the shaft member having an outlet end near an outlet end of the housing body, said shaft member, said stem and said inlet nut having a common central passage to conduct fluid from said inlet nut to said outlet end; an inner wall of said housing body and a portion of said shaft having complementary shaped surfaces together forming a regulating passage therebetween; said shaft member having one or more bores communicating between the inlet bearing area and the regulating passage, wherein pressure of fluid within said regulating passage acts axially upon said shaft to counter axial force on said shaft resulting from fluid pressure axially acting upon said head.