Mechanism for fixing a blood centrifuge bowl to a rotating spindle

Abstract

A mechanism for fixing a blood centrifuge bowl to a rotating spindle is disclosed having two parts. The first part converts downward movement of an outer collar of a chuck into inward and downward pressure against a blood bowl to be secured in the chuck. The second part of the invention converts centrifugal forces present in a rotating chuck into downward pressure on the collar described above. In the preferred embodiment of the invention, the chuck comprises a base plate, plungers, a finger ring and a collar. The base plate receives and positions the blood bowl. The finger ring has a series of fingers located around its upper periphery that pivot around living hinges into contact with the blood bowl. The collar has an annular sloping finger contacting surface that contacts the outer surface of the fingers and forces them inward and downward into contact with the blood bowl. The base plate has a series of outwardly directed bores that hold plungers. Under rotation of the chuck, the plungers move outward in the bores under centrifugal force and contact a sloped plunger contacting surface on the inner surface of the collar. As the centrifugal force increases, the pressure exerted on the plunger contacting surface by the outer ends of the plungers increase causing the collar to be pressured to move downward. Downward pressure on the collar is translated into downward pressure on the finger contacting surface which in turn is translated into inward and downward pressure on the blood bowl.