Abstract: A breakaway base for use with an ultracentrifuge rotor wherein the base is designed to fracture when the rotor is above a specified speed so that the rotor will disengage from the drive spindle of the centrifuge. The base has cutout areas to establish a high stress region that is designed to fracture above a specified rotor speed. The cutout areas are designed to receive lugs projecting from the bottom of the rotor. The cutout areas have slotted ledges through which fastening bolts connect to the lugs on the rotor. The fracture of the base in the high stress region in conjunction with the slotted ledges will result in the base fracturing into two parts which will cause rotor disengagement from the drive spindle of the centrifuge and prevent the rotor from spinning at a greater speed.

Abstract: End caps that are press fitted to the ends of an analytical column tube and to a precolumn tube are abutted to form a fluid flow path. The end caps include projections around the fluid flow path to form a void between the opposing faces of the end caps. A gasket seal is retained within the void to provide a seal for confining pressurized fluid to the flow path. The analytical column extends into a stepped bore in a holder body. A wider diameter portion of the stepped bore receives the analytical column end cap and provides a stop for supporting the compressive load required to maintain the seal.

Abstract: An improved motor speed control system for high speed, high resolution motor control applications such as centrifuges is presented. A proportional, or proportional and integral motor control system is provided with improved circuitry which uses digital phase lock techniques to generate a speed difference signal that accurately reflects the difference between the actual and desired speed of the motor. This speed difference signal is used to adjust the speed of the motor until the actual and desired speeds become approximately equal to one another. An error integrating network may then be enabled to eliminate any remaining difference between actual and desired speed, thereby assuring a negligible speed error.

Abstract: A centrifuge rotor is provided with a plurality of cavities having a non-circular cross-section for receiving mating multi-angle adapters, which may be inserted in the cavities with selected rotational alignment about the cavity axes, to determine a plurality of select angle receiving chambers in the rotor for sample containers.

Abstract: An apparatus for determining the actual speed and maximum safe speed of a centrifuge rotor. A single circular array of equally spaced coding elements of two clearly distinguishable types is attached to the rotor. A single detector responsive to the coding elements produces an output signal that varies in accordance with both the number and type of the coding elements. A first circuit network is responsive to the number of coding elements encountered per unit time, without regard to type, to produce an actual speed or tachometer signal. A second circuit network is responsive to the number of coding elements of each type encountered during each revolution of the rotor, without regard to the speed thereof, to produce a rotor identification signal that is indicative of the maximum safe speed of the rotor.

Abstract: A centrifuge rotor is claimed which comprises a rotor having a plurality of radially extending arms, having a construction to matably receive a pin structure within a recess formed in the upper surface of the rotor, to support the pin structure against loads generated by centrifugal force without stressing a fastener. In assembly, the pin structures permanently mount trunnions for receiving a sample container, for pivotal movement, in a manner such that the trunnion and sample container cooperate to resist stresses and deformation caused by centrifugal loads.

Abstract: A system for cooling and lubricating the drive motor of a centrifuge. The shaft of the motor includes an internal passage with an inlet having a size and taper sufficient to provide the desired rate of cooling oil flow through the motor. A lower bearing proportioning arrangement applies a high percentage of a small proportion of the total oil flow to the lower bearing. An upper bearing proportioning arrangement applies a low percentage of a large proportion of the total oil flow to the upper bearing. Together these features assure a high degree of motor cooling without overlubricating the bearings.

Abstract: A temperature control system used to precisely and accurately control the temperature of a fluid stream in an analytical system designed for investigation of the chemical constituents of the fluid stream. One example of use is in chromatography such as for the chromatographic column in an amino acid analyzer system. The temperature control system utilizes a set of thermoelectric modules to transfer heat between a thermoconductive block which holds the chromatographic column and an air exchange heat sink which obtains heat from or disposes heat into ambient air as required. The control system regulates the temperature at a very rapid rate in order to minimize the recycle time of the instrument.

Abstract: An apparatus for removing liquid contaminants from the oil sump of a vacuum pump. A liquid separator mounted on the housing of the pump connects the interior of the pump housing to the atmosphere through a liquid trap. An inlet passage through the separator connects a source of purging air to the interior of the pump housing, causing the air therein to flow through the liquid trap to the atmosphere. Because outflowing purged air is cooled by inflowing purging air, oil is selectively retained within the pump housing.

Abstract: A temperature control apparatus for a high temperature reactor in an analytical instrument of the type in which a development reagent is added to a flowing stream as part of the detection process. The temperature control apparatus utilizes solid state heat transfer means to transfer heat between a thermoconductive block to which is mounted the reactor and an air exchange heat sink which obtains heat from or disposes heat into ambient air as required. The control apparatus regulates the temperature of the reactor at a very rapid rate in the high temperature range of approximately 90.degree. C. to 150.degree. C. without the use of a separately contained heat exchange medium. The ability of the apparatus to cool the reactor rapidly eliminates the requirement to keep reactor contents at elevated pressures to prevent vaporization of the stream being analyzed.

Abstract: Method and apparatus for authenticating documents such as government notes and currency, stock certificates, and the like by marking the document with an encapsulated dyed liquid crystal material and examining the document for unique optical characteristics of the mark. Reading apparatus for the document measures changes in reflectivity of the liquid crystal mark with changes in an electrical field applied thereto. In other embodiments, reflectivity is measured at a plurality of different wavelengths. In one embodiment, the dye absorbs in regions of the electromagnetic spectrum "invisible" to the human eye and the reading apparatus monitors reflectivity changes at these invisible wavelengths.

Abstract: 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.

Abstract: A thermoelectric temperature control assembly for transferring heat to or from a heat sink. A nonconducting substrate is provided with a plurality of mounting openings for receiving the mounting features of a plurality of respective thermoelectric devices. Each mounting openings is internally partitioned so as to form a pair of flexible tongues by which the thermoelectric devices may be clamped to a heat sink to assure a good thermal contact therewith.

Abstract: A thin-wall centrifuge tube having multiple chambers for use in fluid sample investigation with an ultracentrifuge. More particularly, the multiple chamber ultracentrifuge tube can be used, for example, in lipoprotein separation. The ultracentrifuge tube may have two or more separate chambers which, subsequent to centrifugation, can be sealed from each other to retain the separated constituents of the sample under investigation. The chambers in the tube are joined by a constricted area which permits fluid communication between the chambers. The tube is designed to be used in conjunction with a support spacer adjacent the constriction in the tube so that the tube is properly supported during high speed centrifugation.

Abstract: A hanger for supporting one side of a swinging bucket in a centrifuge rotor. The hanger is adapted for use in pairs, mounted one on each side of a space in a rotor, for containing a swinging bucket. The hanger is provided with an opening for receiving the pivot pins of the bucket and supporting it thereby. Ramp means are disposed on the upper side of the hanger for guiding the pivot pin of the bucket into the opening in the hanger, thereby enabling the pivot pin to be self-seating in the hanger through the effect of gravity when the bucket is deposited in the rotor. The hanger includes spring means for enabling the pivot axis of the bucket to move radially outward in response to centrifugal force and enable the bucket to engage a portion of the rotor.

Abstract: Apparatus for establishing a "home" position for a load element driven axially along the lead screw. A position sensor includes a first sensor element attached for axial travel with the load element and a second sensor element attached for rotation with the lead screw. The pair of sensor elements is operatively aligned at a predetermined relative axial and rotational position establishing the "home" position.

Abstract: A pH electrode which is capable of withstanding repeated exposures to sterilizing temperatures. An electrode body having a pH sensing member is at least partially filled with a bed of electrochemically inert particles. After an internal reference is inserted into the particle bed, the bed is injected with a quantity of electrolyte which is sufficient to establish continuity between the sensing member and the internal reference, but which is not sufficient to produce destructive internal pressures when the electrode is subjected to sterilizing temperatures. The electrode is completed by forming a seal between the electrode body and the internal reference.

Abstract: An assembly for sealing the access passageway to a detector chamber in a scintillation counter instrument. The seal is designed to prevent the entry of any exterior light or environment that could affect the counting or scintillation process when a sample is positioned in the detector chamber. The sealing mechanism operates in conjunction with the scintillation instrument's flexible transport or elevator mechanism that moves a sample containing vial into the detector chamber. A plurality of rotating blades engage the elevator mechanism to form the tight seal. Included in the arrangement is a redundant system to provide a dual sealing capability. The sealing mechanism operates in conjunction with the flexible transport member which allows itself to be centered by the sealing mechanism to achieve the required light seal.