Abstract: A system for transmitting a database or other software over a communication link, such as the Internet, which prevents unauthorized use. In order to prevent such unauthorized use, the customer's equipment, such as a GPS unit, is provided with a unique software key. The updated database is ordered over the communication link by providing the unique software key and may include electronic payment information. The database is encrypted, for example, as a function of the unique software key and transmitted over the communication link in encrypted form along with an upload program. The upload program only allows the encrypted database to be uploaded into a unit with a matching software key. As such, the system allows updated databases to be transmitted rather quickly and easily over a communication link while preventing unauthorized use.

Abstract: The present invention is directed to a self-contained refrigerant recovery and purification system capable of removing gaseous refrigerants from a disabled refrigeration unit for cleaning acid and impurities from the refrigerant so that the refrigerant can be reused or saved rather than being lost to the atmosphere or otherwise wasted. In addition to the feature of saving, cleaning and returning the refrigerant to the repaired refrigeration unit, the present invention can be used as a temporary condensing unit, or for clearing oil restrictions from lines in the refrigeration unit with a high-pressure build-up feature, or as a vacuum pump.

Abstract: An illustrative embodiment of the invention provides pressure relief valve means for the core support cylinder of a nuclear reactor vessel during a failure or accident of the nuclear reactor system. The valve means is responsive to differential pressure across the valve which in one direction sealably seats the valve plate against the valve body, and which, in the other direction opens the valve for pressure relief of the cylinder. Moreover, the valve means is provided with energy absorbing means which limit the impact load of an "explosively" opening valve on the reactor vessel wall.