Abstract: Hand-held apparatus for detecting presence of halogen refrigerant agents in air in which a pair of ultrasonic transducers are spaced from each other within a measurement probe and test air is continuously drawn between the transducers by a fan. One transducer is energized at constant ultrasonic frequency, and the other transducer is coupled to a rectifier or a phase detector for providing a measurement signal as a function of radiation received at and reflected by such other transducer. A reference signal level is established by selectively sampling and electronically storing of the measurement signal, such that the reference level is automatically or manually updated to reflect changes in ambient conditions. An audio/visual alarm is activated when the measurement signal departs from the ambient reference level by more than a preselected threshold.

Abstract: A refrigerant recovery system that includes a refrigerant storage container, means for withdrawing refrigerant from a refrigeration system to be serviced and feeding such refrigerant to the container for storage, and a scale supporting the container for sensing impending overfill of the container. The scale includes a beam horizontally rigidly cantilevered from a base. A switch is positioned adjacent to the cantilever-remote end of the beam, and is responsive to deflection of the beam to indicate impending overfill of the container and prevent or terminate operation of the refrigerant recovery system.

Abstract: Apparatus for analyzing air conditioning systems comprising a temperature probe adapted for manual placement at each of a plurality of preselected points in turn around the refrigerant loop to provide signals indicative of temperature at each point. Apparatus electronics are coupled by a cable to the temperature probe and includes facility for reading and storing each of the probe temperature measurements in turn. Information indicative of standards and ranges of temperature data for properly operating refrigeration systems of a number of models and manufacturers is prestored in apparatus memory. The system temperature readings are compared to each other and to the prestored data to diagnose a plurality of fault conditions and to display diagnosed fault conditions to an operator.

Abstract: Apparatus for service and recharge of refrigeration equipment, with particular application to automotive air conditioning equipment. A vacuum pump, and oil and refrigerant charge containers are housed within a portable enclosure and configured for selective connection by electrically operated solenoid valves to refrigeration equipment under service. The refrigerant and oil containers are carried by a scale which provides electrical outputs signals as a function of weight of refrigerant and oil remaining in the containers. A microprocessor-based controller receives the scale signals and control signals from an operator panel for automatically cycling through vacuum, oil charge and refrigerant charge stages in a programmed mode of operation. The microprocessor-based controller includes facility for operator programming of the vacuum time and oil and refrigerant charge quantities, and for self- or operator-implemented diagnostics. Operating conditions and stages are displayed at all times to the operator.

Abstract: The invention pertains to a lightweight and concise vaccum pump particularly suitable for servicing refrigeration systems. One end of a cylindrical electric motor casing is enclosed by a substantially cylindrical adapter upon which a pump assembly is mounted. The motor armature shaft extends through the adapter and the pump rotor is directly mounted thereon. A hollow shell affixed to the adapter encompasses the pump assembly defining a chamber thereabout which includes a lubrication sump. A synthetic plastic handle assembly attaches to the motor casing and includes a capacitor housing and a base is affixed to the lower side of the casing. Except for the handle and base the pump is of a substantially cylindrical configuration of a diameter similar to that of the motor casing, and the pump assembly includes lubrication and exhaust features which provide improved pumping conditions.

Abstract: The invention pertains to a two-stage vacuum pump for servicing refrigeration systems wherein a pair of electrically driven rotors support movable vanes engaging the cylindrical circumference of pumping chambers in which the rotors are mounted. The improvements pertain to the sealing of the rotor shaft, the introduction of metered oil into the pump, and the keying of a rotor to its driveshaft wherein improved assembly and operational characteristics are achieved.

Abstract: The invention pertains to a two stage vacuum pump particularly suitable for servicing refrigeration systems wherein a pair of electrically driven rotors support outwardly movable vanes engaging the cylindrical circumference of pumping chambers in which the rotors are mounted. The efficient relationship of components produces a high capacity pump in a concise configuration, lateral sides of the rotors are recessed to produce rapid seating of the vanes, reduce hydraulic end loading of the second stage rotor and minimize friction. The vanes are offset from the associated rotor axis to allow greater displacement for a given chamber bore and rotor size, and advantageous frictional forces are produced to augment sealing between the vane tips and chamber surface. Further, the vane tips are shaped to optimize compression and reduce gas re-expansion, and the rotors of the two stages are rotationally phased to improve capacity and pumping characteristics.