Abstract: To provide a vacuum-tight seal to the rotor of a gradient zone separation rotor, the rotor shaft (15) is formed with a circumferential groove (7) which can receive balls (6) located in radial grooves of a cover cap (2), and movable to engage positions with the circumferential groove (7) by an outer holding sleeve (3), or releasable engagement by pulling up on the sleeve (3) against spring pressure.

Abstract: To prevent uneven rotary speeds of the inner rotor of a nested triple-rotor centrifuge in which a separating container is located in an inner rotor and connected by means of soft-elastic integral connecting tubes with the outside of the centrifuge, and without slip joints, and wherein the three nested, coaxially positioned rotors are independently rotatable with respect to each other, a positive synchronizing drive connection (25, 33) is established between the outer rotor (4) and the drive connection (27, 28, 29, 30, 31, 32) of the inner rotor (6); the centrifuge is particularly suitable for centrifuging blood during or immediately following blood donation to permit separation of blood plasma and return of erythrocytes to the donor.

Abstract: To provide for resilient hanging and outwardly swinging support of sample holder cups to be placed on the rotor of a centrifuge, a ring-shaped element is located axially offset from the holding portion for the cups of the rotor, the ring-shaped element having axially extending bores formed therein into which rod or strip spring elements are inserted, extending essentially axially along the rotor axis and then being bent over laterally outwardly and terminating in an L or P-shaped hook end so that the sample holder cups can be hooked therein for outward swinging movement. Preferably, the rotor and the sample holder cups are formed with interengaging abutments to limit outward movement of the cups during operation. The rotor itself is preferably formed with a groove to receive the horizontally extending portion of the spring elements. Additional restraining means can be provided to restrain undue deflection of the spring elements during rotor operation.

Abstract: To gently stop a centrifuge, particularly for use in blood transfusion procedures including plasmapheresis, a centrifuge motor is first braked by reverse current application with high braking torque, to reduce the speed thereof from operating speed to less than 1000 rpm, for example between 800 to 500 rpm; and then braked under dynamic braking conditions, preferably under continuously variable torque conditions, until it is about stopped, for example at close to 50 rpm, and then permit it to coast to a stop. The braking is effected gently and can be achieved from a nominal speed of 6000 rpm to stopped condition in about 2 minutes, thus permitting blood centrifuging for plasmapheresis in about 8 minutes.

Abstract: To permit light-weight construction of a rotor of a centrifuge holding sample carriers adapted to retain probes, the rotor is formed at its outer circumference with a sleeve of at least partly fiber-reinforced plastic. The holders are secured to the rotor and movable in guide means so that when swinging outwardly under centrifugal force, they can abut against the outer sleeve, preferably with interposition of a segmental element to provide for large area contact, the fiber-reinforced plastic sleeve, being continuous and circular, absorbing centrifugal forces.

Abstract: The centrifuge rotor is formed with a central chamber and two peripheral annular chambers concentric therewith; an annular bag including ring-shaped compartments, made of flexible material, and with communicating ducts are placed into the three chambers, the central chamber additionally being big enough to accommodate a holder for treatment liquid and for the reception of treated biological fluid, after centrifuging and treatment; valves, which may be centrifugally or otherwise operated, control flow between the central bag compartment in the central chamber of treatment liquid to the intermediate bag compartment in the intermediate chamber, and flow from the intermediate compartment of used treatment fluid to the outer peripheral compartment. A dimensionally stable, bulged, disk-shaped body is located in the compartments to assure that the bag retains its shape.

Abstract: A housing retains an essentially disk-like center element made of light-tsmissive material, or formed with an opening therein, and shaped to receive a capillary tube (or formed with a capillary opening itself) extending radially transversely to the disk-shaped element, essentially half-way in the thickness thereof, the central element being bounded on at least one side by window-like diaphragm elements, either separate parts or incorporated on the central part to define a light path through the capillary tube to permit centrifuging and optical investigation of minute quantities of substances to be tested by centrifuging, for example blood sera to determine sedimentation.