Beckman Instruments, Inc.

Beckman Coulter, Inc.

Herschel E Wright

Robert C Wedemeyer

Robert H Giebeler

Kenzo Ishimaru

Robert J Ehret

Charles Godin

Lawrence E Stahl

Derek G Petch

Cory Y Chern

Jan Zaluda

Victor V Pederson

A rotor drive shaft assembly for use in a centrifugation system. The rotor drive shaft has a bearing material configured as a sleeve and mounted on the inside wall of a spindle hub with a clearance existing between the sleeve and a housing that surrounds the lower base of the shaft. When the rotor and hub experience radial displacement at a critical speed, the sleeve makes contact with the housing in order to limit further radial displacement. Alternatively, the sleeve can be mounted on the outside of the housing with the clearance existing between the sleeve and the spindle hub, with the sleeve making contact with the spindle hub at the critical speed in order to limit further radial displacement. In another embodiment, a support tube is provided which surrounds the lower portion of the shaft with a clearance existing between the shaft and the support tube. When the shaft experiences radial displacement at the critical speed, the shaft makes contact with the support tube which limits further radial displacement.

Rotor shaft assembly having non-linear stiffness

An improved configuration of refrigerant tubing and means for attaching the tubing to the centrifuge chamber. The tubing is preformed to provide a flat contact surface against the outside surface of the centrifuge chamber. The centrifuge tubing is tightly wound around the centrifuge chamber in a continuous fashion including a flat spiral at the base of the centrifuge chamber. For the section of the tubing in contact with the vertical cylindrical wall of the centrifuge chamber, the pressure for maintaining contact pressure between the flat surface of the tubing and the chamber wall is provided by the tension in the wrapping of the tubing. For the section of the tubing at the base of the centrifuge chamber, contact pressure may be provided by a clamping mechanism. To further enhance heat transfer between the refrigerant coils and the centrifuge chamber, a high heat conductive epoxy may be applied between the tubing and the centrifuge chamber surface. Due to the tight winding of the tubing and the flat contact surface between the refrigerant tubing and the chamber wall, there is optimum use of surface area for maximum and efficient heat transfer between the chamber and the tubing.

Refrigerant cooling assembly for centrifuges

A centrifuge includes a drive shaft-to-hub coupling assembly for providing vibration damping that is selective to torsional damping over lateral damping. An impeller is fixed to a drive shaft and a receiver is fixed to a rotor-bearing hub. Relative rotation between the impeller and the receiver is restricted to compression and decompression of elastomers trapped between teeth extending from the impeller and from the receiver. The elastomers function to damp torsional vibrations and torsionally induced lateral vibrations. The receiver is prevented from becoming axially misaligned with the impeller by including one or more rigid annular bushings that maintain the distance between the hub and the drive shaft, thereby preventing the elastomers from being deformed in a manner which would damp lateral vibrations. The annular bushing is mounted to allow relative rotation between the impeller and the receiver.

Torsionally elastic assembly for driving a centrifuge rotor

An assembly for transferring rotation from a centrifuge drive system to a centrifuge rotor includes a hub that is connected to the drive system for rotation about an axis. A sleeve member is attached to the hub in a position to support the centrifuge rotor. The sleeve member is formed of a material having a low coefficient of friction and is positioned to reduce the likelihood of rotor-to-hub lock. The resistance of the sleeve member to wear and to the absorption of foreign matter are also important in the selection of a material for forming the sleeve member. An acetal-based compound is preferred. By connecting the sleeve member to the hub such that the exterior surface of the sleeve member is raised relative to the surface of the hub, rotor-to-hub contact is reduced, thereby further reducing the risk that the rotor and the hub will become locked to one another.

Centrifuge drive-to-rotor assembly

A device for centrifugally separating a sample includes a housing which defines an enclosed chamber from which gas is evacuated via an evacuation port protected by a spinning rotor. The evacuation port is preferably located proximate to the axis of rotation of the rotor and within the interior of the rotor. A drive shaft connects the rotor to a motor positioned outside of the chamber. An annular sleeve having an inside diameter greater than the diameter of the shaft extends coaxially along the drive shaft into the chamber. The outlet of the gap between the drive shaft and the annular sleeve defines the evacuation port. A hub is fixed to the upper end of the drive shaft and includes a downwardly depending skirt that has an inside diameter greater than the outside diameter of the annular sleeve. Gas evacuation from the chamber is initially in an upward direction along the gap between the hub skirt and the sleeve and in a downward direction from the evacuation port to a vacuum pump. Preferably, the vacuum pump is also joined to the drive motor.

Rotor-protected evacuation port for centrifugal separation

A salt belt for insertion into a centrifugal test rotor is provided which is used to hold and contain a plurality of test components during mechanical testing. The slat belt is a flat polymeric belt which adhesively affixes a plurality of L-shaped slat members to its upper surface. When the belt is laid flat, it accommodates the easy positioning of components into channels. As the belt is curled for insertion into the test rotor, the slats move closer to one another and clasp the components into channels formed by adjacent pairs of radially directed slat arms. Upon completion of the test run, the slat belt is removed from the rotor and unrolled whereby the components are easily removed from the belt.

Slat belt for centrifugal test rotors

A liquid flow monitor. The device includes a thermistor placed in the path of liquid flow. A circuit including the thermistor in a Wheatstone bridge is used to sense the liquid flow by sensing the change in resistance of the thermistor. A transistor connected to the bridge is used to maintain the thermistor within predetermined levels to prevent overheating of the device.

Method and apparatus for monitoring liquid flow

A tube-cutting apparatus and method for separating centrifuged materials are shown in which a resilient axial compressive force is exerted on the tube during cutting by spaced tube-holding members; and the cutting knife has flat upper and lower sides against which the severed portions of the tube are held in sealing engagement by the axial force. Independent adjustment is provided for (a) the relative positions of the tube and the cutting knife, and (b) the relative positions of the spaced tube-holding members.

Centrifuge tube-cutting apparatus and method

A thick walled centrifuge tube with a generally constant internal diameter and having at least one circumferential groove within the exterior surface of the tube. The groove is designed to have a depth slightly less than the wall thickness of the tube. The circumferential groove is designed to assist in slicing of the tube subsequent to centrifugation in order to isolate different separated particles of a fluid sample which have formed fraction bands at certain levels in the tube. The groove reduces the cutting force required to partition the tube. The groove provides a guide for a slicing blade. The groove is formed in such a manner that a fluid tight seal is formed between the slicing blade and the tube as the blade proceeds through the tube. The centrifuge tube wall at the base of the groove, after slicing, is resilient enough to allow the tube sections to be rejoined under force and create a fluid tight seal.

Pregrooved centrifuge tubes

A variable slip drive system for driving a variable speed induction motor. The system includes a tachometer for providing a signal proportional to the speed of the motor and a slip oscillator. The output of the tachometer and slip oscillator are combined by a motor drive oscillator to provide a motor drive signal. The frequency of the motor drive signal equals the tachometer signal, less the frequency of the slip signal. The motor drive signal is converted into a proportional, three-phase, high power signal for powering the motor. The frequency of the slip signal is controlled so as to be proportional to the motor speed as a means of optimizing the motor's performance.

Variable slip drive system for induction motor

A centrifuge rotor for carrying a plurality of centrifuge tubes at a fixed angle with respect to the spin axis of the rotor wherein the rotor has a containment annulus located above the tube cavities in the rotor for containment of any excess fluid from the centrifuge tubes during centrifugation. The containment annulus is designed in such a manner that it will receive all possible excess fluids from the centrifuge tubes during centrifugation and none of the excess fluid will contact or exert pressure on the rotor lid.

Fluid containment annulus for fixed angle rotors

A rotor having a plurality of swinging carriers designed to receive specimen samples for subjection to centrifugation. The carriers are pivotally mounted to a rotor frame in such a manner that the generally flat support faces of each of the carriers assumes a parallel orientation with respect to the rotational axis of the rotor during operational speeds of the rotor. When the rotor is not operating, the support surfaces of each of the carriers assumes the perpendicular or acute angle orientation with respect to the rotational axis of the rotor. In order to overcome any resistive frictional forces which may be generated at the interface between the rotor frame and the pivoting carrier, the pivot axis of the carrier is shifted from the central or center of gravity plane of the carrier to ensure that the support surface of the carrier will positively assume its proper parallel orientation with the rotor spin axis. Means are incorporated into the carrier or the rotor to limit the swinging effect of the offset pivot axis of the carrier, so that the support face will not go beyond its parallel orientation with the spin axis. The present rotor device incorporates a holding means to maintain the support base of the carrier at an acute angle to the rotational axis of the rotor when the rotor is at rest.

Swinging carrier centrifuge rotor

An adjustable supporting arrangement used within the sample receiving cavity of a centrifuge rotor to hold and align a plurality of test tubes. The arragement is comprised of a series of similarly configured interface layers which can be variably arranged to accommodate different sized test tubes. A bracket member is utilized to retain the alignment of the various interface layers and hold them as a single unit for convenient movement into and out of the rotor cavity. Incorporated within the supporting arrangement is a separate cushion pad to receive the bottom ends of the test tubes. A uniquely designed divider plate can be placed within the supporting arrangement to partition the rotor cavity into two areas for receipt of two sets of test tubes in stacked relation.

Adapters for centrifuge rotors

A vacuum seal for use in a continuous flow centrifuge apparatus for minimizing heat transfer from the vacuum bushing to the rotary transfer tube which is conducting the sample solution to the centrifuge rotor. An elongate, cylindrical sleeve surrounds the transfer tube, coaxial therewith and spaced therefrom, adjacent the upper end thereof, between the transfer tube and the vacuum bushing, the bushing creating an oil film around the transfer tube to provide the vacuum seal, the annulus formed between the inner surface of the sleeve and the outer surface of the transfer tube isolating the transfer tube from the heat created in the oil film.

Continuous flow centrifuge apparatus

In a centrifuge rotor of the type including a yoke and an enclosure for the yoke, the enclosure being operatively connected to the yoke for rotation therewith, the enclosure comprising a wind shield physically connected to the bottom of the yoke and extending beneath the yoke and around the sides thereof and a lid being positionable over the yoke to engage the wind shield for completely enclosing the yoke, there is disclosed a method and means for retaining the lid in contact with the wind shield wherein the wind shield terminates in an upwardly facing circular lip and the cover terminates in a downwardly facing circular lip so that the lip of the lid engages the lip of the wind shield, there being no physical connection between the lid and the wind shield, the lid being retained in contact with the shield during rotation of the centrifuge rotor by the force created by the naturally-occurring low pressure within the enclosure, beneath the lid.

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Santa Clara, CA, United States of America

Herschel E Wright