Apparatus for accomplishing unlimited relative rotation of the ends of a filiform transmission element

Centrifuge apparatus for continuous separation of a liquid into fractions of different densities, comprising:

• a base,
• inner, intermediate and outer rotors which are rotatable relative to one another and relative to the base about a common centrifuge axis,
• drive means for rotating the intermediate and outer rotors in opposite directions at approximately the same speed and for rotating the inner rotor in the same direction as the intermediate rotor at a speed equal to twice the sum of the speeds of the intermediate and outer rotors,
• a filiform flexible transmission element having one end thereof non-rotatably fastened to the base and having the opposite end thereof non-rotatably fastened to the inner rotor,
• first holding means holding a first length of the transmission element in position on the outer rotor along a first bight line extending from a point near the centrifuge axis out around the region occupied by the intermediate rotor and back to the centrifuge axis, the ends of the bight lines pointing in the same direction along the centrifuge axis,
• second holding means holding an adjoining second length of the transmission element in position on the intermediate rotor along a second bight line forming a continuation of the first bight line and having both ends thereof pointing along the centrifuge axis oppositely to the direction of the ends of the first bight line so that the ends of the transmission element point in opposite directions along the centrifuge axis, the second bight line extending from the inner rotor out around the region occupied by the inner rotor inwardly of the first bight line and back to the centrifuge axis where it merges with the first bight line,
• a separation container removably held on the inner rotor, and
• flexible inlet and outlet tubes, each fixedly secured at one end thereof to the separation container for passing liquid into and out of the separation container, said tubes extending together with the transmission element along the first and second bight lines and said transmission element and tubes being rotatable in said first and second holding means relative to the outer and intermediate rotors.

A detachable separation unit for use in a centrifuge apparatus of the type having a stationary base, at least two rotors mounted in the base for rotation relative to one another and relative to the base about a centrifuge axis, drive means for rotating the rotors at different speeds, one of the rotors having means for receiving a separation container, and the other rotor having holding means for holding a bundle of flexible tubes fastened to the separation container in position on said other rotor during the relative rotation, said separation unit comprising in combination:

• (A) A closed container of flexible sheet material receivable in a pocket on said one rotor, said container having an internal tubular configuration and its external ends being free of each other;
• (B) A bundle of flexible tubes fastened to said closed container, at least one of said flexible tubes opening into said container near one end thereof and at least one of the other flexible tubes opening into said container near the opposite end thereof;
• and
• (C) An elongated, flexible but torsionally rigid sheathing enclosing said bundle of flexible tubes and including means for non-rotatably detachably fastening the ends thereof respectively to the base and said one rotor.