Abstract: A reciprocating pump which substantially eliminates cavitation problems without imposing capacity and flow limitations to maintain a net positive suction head.

Abstract: First and second multi-stage cryogenic refrigerators each have a displacer driven by a common motor so that the displacers are substantially 180.degree. out of phase. The final stage of each refrigerator has a regenerator arranged in a heat exchange relationship with counterflow.

Abstract: The cryogenic refrigerator includes a movable displacer within an enclosure having first and second chambers of variable volume. A refrigerant fluid is circulated in a fluid path between said chambers and correlated with movement of the displacer. A spool valve controls introduction of high pressure fluid and low pressure fluid to said chambers in a manner so that such flow is correlated with the pressure difference across said valve.

Abstract: In a cryogenic refrigerator, a valve member reciprocates to control fluid to and from chambers of variable volume. The valve member is moved in one direction by a cam and in the opposite direction by a fluid spring.

Abstract: The cryogenic refrigerator includes a movable displacer within an enclosure having first and second chambers of variable volume. A refrigerant fluid is circulated in a fluid path between said chambers and correlated with movement of the displacer. A spool valve controls introduction of high pressure fluid and low pressure fluid to said chambers. The displacer movement is controlled by an electric motor which has a cam for reciprocating the spool valve member. The refrigerator is converted into a source of heat by reversing the direction of rotation of said electric motor.

Abstract: A joint is made from first and second vacuum spool pieces connected end to end. Each spool piece includes an inner conduit surrounded by and spaced from an outer jacket. Each outer jacket includes an expansion-contraction portion adjacent each end thereof. Each end portion of each jacket has a first member in sealing contact with a mating second member on the inner conduit for retaining a vacuum in the annular space. After two spool pieces are joined, the first and second members are shifted relative to one another so as to preclude any direct conductive heat leak path and permit the vacuum in the annular space of one spool piece to communicate with the vacuum in the annular space of the other spool piece.

Abstract: In a cryogenic refrigerator, a refrigerant is circulated in a fluid flow path between first and second chambers by the movement of a displacer means. A slide is connected to the displacer means and reciprocated by a motor. The slide has an axial passage communicating the first and second chambers. The slide has a piston for varying the volume of gas in a third chamber during its reciprocation. The need for a separate compressor is eliminated.

Abstract: A cryogenic refrigeration is disclosed for operation in a first mode wherein an electrical motor reciprocates a displacer, and in a second mode wherein the displayer is reciprocated by both the motor and fluidic pressure, and in a third mode wherein the displacer is reciprocated by fluidic pressure.

Abstract: The inner cryopanel of a cryopump includes a substrate having a plurality of holes such that the open areas represent 30% to 70% of the surface area of the substrate. A layer of cryosorbing material is secured to one surface of the substrate. An imperforate panel is juxtaposed to said one surface of said substrate.

Abstract: A valve housing is cooled to minimize any temperature gain by the fluid being controlled. The valve member is moved by an actuator toward and away from a seat to control flow through the housing. The valve member and its stem are made from a heat conductive material. The valve member and its stem are cooled by conduction when the valve member is in an open or closed position.

Abstract: The cryogenic refrigerator includes a movable displacer within an enclosure having first and second chambers of variable volume. A refrigerant fluid is circulated in a fluid path between said chambers and correlated with movement of the displacer. A spool valve controls introduction of high pressure fluid and low pressure fluid to said chambers. The displacer movement is controlled by an electric motor which has a cam for reciprocating the spool valve member.

Abstract: The cryogenic refrigerator includes a movable displacer within an enclosure having first and second chambers of variable volume. A refrigerant fluid is circulated in a fluid path between said chambers by movement of the displacer. A spool valve controls introduction of high pressure fluid and low pressure fluid. The displacer movement is controlled by fluidic pressure instead of an electric motor.

Abstract: The cryogenic refrigerator includes a movable displacer within an enclosure having first and second chambers of variable volume. A refrigerant fluid is circulated in a fluid path between said chambers by movement of the displacer. A spool valve controls introduction of high pressure fluid and low pressure fluid. The displacer movement, at least at top dead center and bottom dead center is controlled by an electric motor.

Abstract: The cryogenic refrigerator includes a movable displacer within an enclosure having first and second chambers of variable volume. A refrigerant fluid is circulated in a fluid path between said chambers by movement of the displacer. A spool valve controls introduction of high pressure fluid and low pressure fluid. The displacer movement is controlled by an electric motor.

Abstract: A closed loop refrigeration process and apparatus provides a large flow of cold, supercritical gas through a device which is to be cooled at cryogenic temperatures. The output of helium gas from a compressor is precooled with liquid nitrogen and divided into two streams which are cooled by expansion and by heat exchange with the return flow of helium to the compressor. The two streams are recombined and further cooled by heat exchange with the return flow and a liquid helium bath. The entire output of the compressor, at liquid helium temperature and above critical pressure, is forced through the load. The stream is then expanded through a valve where partial liquefaction takes place to replenish the liquid helium cooling bath. Gaseous helium is drawn off from the liquid helium bath and recycled through the heat exchangers back to the compressor.

Abstract: Cryopump apparatus for evacuating very large chambers to ultra high vacuums includes cryogenic panels alternating with radiation shields having a unique Z-configuration which optically blind the panels. The panels and shields are supported by and housed within structure having specific components slidable along one another to thereby permit necessary movement of the components when the apparatus is subjected to cool-down or warm-up. The apparatus is characterized by very high pumping speeds and is capable of cryopumping from both sides thereof.

Abstract: Cryopump apparatus includes means for supplying cryogenic fluid, means for supplying higher temperature refrigerant fluid, a panel having heat exchange surfaces on respective opposite sides thereof, with a conduit conducting cryogenic fluid therethrough, and a zigzag passageway formed by opposite sides of two radiation shields in spaced relationship with each other having the panel therebetween. The radiation shields are spaced from the panel, optically enclosing the panel therewithin. Corresponding edges of adjacent shields define open bottom channel-configured passageways for flow of gas therethrough to respective heat exchange surfaces of a panel interjacent the shields. The shields include conduits for flow of refrigerant fluid therethrough. Heat insulative positioning spacer means contact two adjacent panels and a shield therebetween, maintaining the panels and shield in spaced relationship.