Universal electrical swivel

Claim 1

A universal swivel adapted to provide rotation and tilt of electrical apparatus about orthogonal axes and to serve as a conduit for an electrical conductor comprising: a base member having a generally smooth outer cylindrical bearing surface and an axial passage, adapted for passage of an electrical conductor, said base member being formed at its outer end with means for attachment to said electrical apparatus and at its inner end with generally conical depression communicating with said axial passage; a central body member formed with an integral cylindrical collar fitted over said cylindrical bearing surface for smooth rotation thereon and formed with a first generally circular dish-shaped portion extending outward from said cylindrical collar, said dish-shaped portion having a cylindrical outer edge surface, the inner end of said collar being substantially flat and sealed but formed with an opening adapted to permit passage of an electrical conductor from said conical depression of said base member through to the inner region of said first dish-shaped portion; an upper body member formed with a second generally circular dish-shaped portion mating with and adapted to smoothly rotate about said first dish-shaped portion of said central body member, said upper body member being formed with an integral portion having an inner cylindrical wall extending over and smoothly mating with said cylindrical outer edge of said first circular dish-shaped portion of said central body member to limit the angle of rotation of said upper body member about said central body member; said base member, central body member and said upper body member being formed of insulative, flexurally elastic polycarbonate substantially impervious to acid and alkali substances; the axis of said outer cylindrical bearing surface of said base member being offset from the axis of said cylindrical collar of said central body member, said collar having a region of increased thickness at one side thereof; said means for limiting rotation of said central body portion about said base member including an annular recess in said base member; a stop formed in said recess, and means projecting into said recess from said collar of said central body member, said last-mentioned means being securely affixed in said collar in said region of increased thickness; the inner surface of said first and second dish-shaped portions cooperating to form a circular hollow chamber; and means for retaining said circular portions of said central and upper body members in frictional engagement for rotation in a plane parallel to the axis of said base member and for sealing said hollow chamber against the passage of moisture therethrough; said upper body member having an integral outward extension adapted for attachment to said electrical apparatus and having an axial hollow passage communicating with said circular hollow chamber; whereby an electrical conductor may pass inward freely through said axial passage and said conical depression in said base member, through said opening in the flat upper end of said central body member and into said circular hollow chamber and outward through said axial passage in said integral hollow extension of said upper body member.