Fluidtight swivel joint

Claim 1

A fluidtight swivel joint comprising a body having a bore with a central axis passing entirely therethrough, and a port intersecting the bore at a location intermediate its ends and opening onto the outside of the body; a rotor rotatably mounted in said bore and extending entirely therethrough and having an axis of rotation coincident with said central axis; an outer wall on said rotor which includes a pair of axially spaced-apart cylindrical portions whose axes are coincident with the central axis and which are disposed on axially opposite sides of the port, the rotor further including a passage extending axially therein and opening onto the outer wall of the rotor in fluid communication with the port; a pair of lip seals, each being a body of revolution and having a substantially disclike mounting flange and a frustoconical sealing lip with a central opening which, when relaxed, is smaller than the said cylindrical portions so as to make a deflected interference sealing fit therewith; a set of circumferential grooves in a face on each end of the body against which the mounting flanges bear; a retainer for each seal mounted to the body and pressing the mounting flange against said grooves so as to deform the mounting flange and form a seal with an undulating face, the lip seals being made of a material selected from the group consisting of polytrifluorochloroethylene and tetrafluoroethylene; and thrust bearing means disposed between the rotor and the body to react any unbalanced forces derived from pressure in the swivel joint.