Abstract: An automatic lay-up machine is disclosed for composite material article having anisotropic resistance in tension. A layer of fiber material, either unidirectional or fabric weave, is dispensed between a supply roll and a take-up roll. This material is advanced over a cutting table having at least one and preferably a plurality of cutting molds, each mold cutting a profile of a portion of an article being fabricated and leaving a continuous scrap webbing for gathering at the take-up roll. The material is placed under tension across the cutting table, compressed, and cut at the molds to extract the individual layers having the desired sections utilized in fabricating the article. This process is repeated with the molds indexing in rotation with respect to the material so that successive layers filling the molds align their respective fibers in varying directions.

Abstract: A swinging bucket rotor constructed of composite material has a central rotor body including strap retaining surfaces. Wound endless composite fiber straps are provided having central portions which are attached to the respective top and bottom of the central rotor body and loop portions remote from the central rotor body for mounting the swinging buckets. These wound endless straps attach centrally to the central rotor body at the strap retaining surfaces and define bucket retaining loops symmetrically spaced from the spin axis of the rotor at the central rotor body. In the preferred embodiment, each bucket retaining loop holds spaced apart bushings for receiving a trunion shaft. Paired trunions on either side of a central sample tube receiving ring are provided. The trunions fit to the composite loop portions of the endless composite material straps. Typically, four sample receiving buckets are placed within and held by the central sample tube receiving rings.

Abstract: A centrifuge construction is disclosed in which a centrally located stator directly drives a peripheral ring shaped centrifuge rotor. In the preferred embodiment, a centrifuge drive is disclosed which includes a stationary, central and usually cylindrical stator having stationary electrical windings for generating a rotating and driving magnetic field. The ring shaped centrifuge rotor is supported by at least one bearing relative to the stator and includes a large central aperture defined by the inside of the ring which enables the rotor to fit over and rotate about the stator. At portions of the rotor adjoining the stator, the rotor is constructed from materials which are entrained by the rotating magnetic field. The centrifuge rotor containing samples undergoing centrifugation is directly driven from the stator by entrainment of the rotor with the rotating and driving magnetic field generated from the electrical windings of the stator.

Abstract: A centrifuge rotor having a balancing ring integrally formed with and raised from the upper surface thereof is manufactured by removing material from the ring to balance the rotor in the upper plane. The balancing ring is on the same radius as the rotor tube cavities and of width less than the diameter of said cavities such that the ring, when the tube cavities are drilled, is broken into segments of precisely known area which make the amount of material to be removed to balance the rotor readily determinable.

Abstract: A hybrid centrifuge rotor having a rotor core surrounded by a prestressed anisotropic reinforcement ring is disclosed. The rotor core may be made from aluminum and an anisotropic reinforcement ring may be a cylindrical filament wound ring, made from graphite fiber and epoxy resin. The rotor core is manufactured to have a nominally greater diameter than the inner diameter of the reinforcement ring. This rotor core, during the manufacturing process, is subjected to a cryogenic environment where the diameter is shrunk down so that the rotor body may fit and telescope within the reinforcement ring. The rotor body core and reinforcement ring assembly, upon attainment of ambient temperatures, have an interface fit wherein substantial outward force from the rotor body core prestresses the reinforcement ring so that a light weight and strong centrifuge rotor is disclosed.

Abstract: A composite material rotor is disclosed which is made from a plurality of stacked and bonded epoxied filament wound discs, each disc providing a specially wound construction so that the modulus of the rotor body may be varied in proportion to the maximum stress encountered by the rotor during ultracentrifugation. Such a layered disc assembly allows the rotor to be fine-tuned to respond to a variety of stress encountered during ultracentrifugation. Where upper hoop stress is greater, upper disc 28 might be wound using a higher modulus filament fiber than the fiber used by disc 26.

Abstract: A swinging bucket centrifuge rotor including seating surfaces having shapes which cause buckets seating thereon to be relieved of side loading forces. Each bucket is symmetrical and is pivotally supported by bucket pins that rest in respective spring-loaded carrier assemblies. The spring constants of the springs of the carrier assemblies are selected so that the leading edge of each bucket bottom rests upon a curved surface and clears the respective seating surface before the trailing edge thereof contacts the same. The resulting bucket orientation assures that, upon seating, each bucket rotates until its bucket pins lift slightly off of the surfaces of the respective carrier assemblies.

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: Balancing bosses integrally forged in a centrifuge rotor. The plurality of balancing bosses in the rotor establish noncritical areas in the rotor for machining to accomplish the precise balancing necessary for high speed ultracentrifugation. The balancing bosses are located away from the high stress periphery of the rotor so that machining a portion of the bosses for balancing purposes will not degrade the integral strength of the rotor.

Abstract: A centrifuge rotor is provided which has a circumferential wall and a plurality of spaced arms which radiate outward from the center to the circumferential wall. A plurality of buckets are mounted on the rotor, one between each arm. Each bucket has two outwardly extending pivot pins situated on a common axis. A plurality of hangers are mounted in the spaced arms of the rotor. Each hanger comprises an elongated housing containing an opening which is transverse to the longitudinal dimension of the housing for receiving the pivot pin of a bucket. A longitudinal bore intersects the opening and contains a spring for exerting a clamping force on the pivot pin when the rotor is stopped. This prevents the bucket from rocking when being loaded or unloaded, but does not prevent the bucket from pivoting to a horizontal position when the rotor is rotating, nor does it prevent the bucket from resuming a vertical position when the rotor is stopped.