Abstract: An easily maintainable interface for magnet dewars which includes a low h leakage disconnect fitting that retains the vacuum integrity of both the dewar and the transfer line is provided. The fitting includes a bayonet-type insert having separate coils disposed about a central conduit for cooling or heating the unit depending upon intended use. Liquid helium is introduced axially through the bayonet which is adjustable to a purge position wherein either gaseous or liquid helium may be introduced to clean, heat or cool the unit, or a flow position wherein liquid helium is passed through the bayonet into the supply line.

Abstract: A coupling for attachment to air conditioning systems to prevent leakage of refrigerant fluid during testing and servicing thereof. The coupling includes an elongated outer housing adapted to be attached at one end to an air conditioning system. The housing is provided with an axial bore in which is positioned an inner cylindrical body member having longitudinal ducts, which member is movable longitudinally with respect to the outer housing. One end of the inner body member is adapted to be selectively engaged with testing equipment or a refrigerant fluid supply. A portion of the inner housing is aligned with a valve of the air conditioning system which is actuated thereby upon longitudinal movement of the inner body member, thereby permitting refrigerant fluid to flow through the ducts in the inner body member from the refrigerant supply to the air conditioning system. Means carried by the inner body member facilitate longitudinal movement thereof.

Abstract: A valve assembly particularly adapted for air conditioning systems and with provision for mounting on a panel or housing wall. The valve assembly has an elongated body with three bosses extending radially therefrom. The body has abutment faces at two of the bosses and has an abutment shoulder at the third boss, which is between the other two bosses. The abutment faces lie in a common plane and are adapted to contact one side of a panel or housing wall that has openings through which the three bosses may project. A jam nut is threaded onto the middle boss for contacting the other side of the panel or housing wall for clamping the same against the abutment faces. The abutment shoulder is inwardly offset a slight distance from the abutment faces to assure that the panel or housing wall will contact the abutment faces when the jam nut is tightened but it will serve as a stop to prevent undue bending of the panel or housing wall under pressure of the jam nut.

Abstract: Closed-circuit cooling processes, and apparatus for performing such processes, in which a working fluid is successively compressed, condensed through the removal of heat, expanded, and vaporised by take-up of heat from a fluid to be cooled, before being again compressed, the working fluid having been obtained by mixing refrigerant, having a boiling point within the range 0.degree. to 60.degree. C at atmospheric pressure, with air having a partial pressure initially, that is prior to use and throughout at least a major part of the volume of the circuit, of at least 0.05 atmospheres absolute.

Abstract: A device for servicing closed refrigerating systems comprising a body having a passageway therethrough provided at its respective ends with threaded members for connecting the device to an access valve of the refrigerant system and a refrigerant charging hose. The body rotatably supports a shaft having a camming surface at one end longitudinally moving a plunger toward a depressible valve core by manual rotation of the shaft for communication with the refrigerant system.

Abstract: A do-it-yourself kit for charging an automobile air conditioning system. A charging hose has a special delivery fitting to be connected first to the charging nipple on the suction side of the compressor of the operating system. Such fitting has a depressor to open the nipple valve and has a check valve to prevent escape of refrigerant by backflow through the hose. The fitting thus isolates the kit from refrigerant pressure. The charging hose also has an inlet fitting for attachment to the nipple of a pressurized refrigerant can, which has a depressor to open the nipple valve. Refrigerant then flows under can pressure to the system. Unused can refrigerant is saved by disconnecting the fittings in reverse order. Since the hose and kit are isolated from system pressure by the check valve, increased safety is obtained and the hose assembly can be made of low-cost materials which can be discarded after use.

Abstract: A refrigerant charging cylinder for vapor refrigeration systems has a valve mounted on a refrigerant tank in which a refrigerant is partially liquid and partially gaseous, with the tank being arranged during use thereof with the gas between the liquid and the valve. Included in the valve is a saturated vapor pipe which extends into and terminates above a maximum level of liquid refrigerant in the tank, while a liquid refrigerant pipe mounted within the saturated vapor tube extends into the liquid refrigerant. By this arrangement, a flow of gaseous refrigerant through the saturated vapor tube will draw liquid refrigerant through the liquid refrigerant pipe, mix the liquid refrigerant with the gaseous refrigerant, and form a vapor that can be fed to the suction side of the compressor of a vapor-compression refrigeration system while the compressor is operating.

Abstract: A tool for maintaining and servicing a pressurized refrigeration system or the like wherein it is desirable to remove and replace a threaded check valve core without depressurizing the system. The tool includes a body member having a longitudinal passageway extending therethrough with means to provide sealing communication between one end of the passageway with the fitting in which the check valve is fitted. A removable cap sealingly engages the opposite end of the longitudinal passageway with an operating shaft extending therethrough for axial and rotary movement within the passageway. An annular sliding seal is disposed between the shaft and the removable cap. The shaft includes engaging means formed on one end thereof for releasably engaging the valve core to unthread and remove it from the fitting and withdraw it into the passageway to a position adjacent to the removable cap.