Abstract: An isolator and method of using same for providing an atmosphere free of contamination from external sources and for containing and evacuating contaminates generated during the course of a surgical procedure, particularly laser procedures that are performed within the isolator. The isolator includes a double chambered structure made of a flexible material on a rigid frame. Filtered air is provided to the outer chamber and enters the inner chamber through various openings in the inner enclosure walls. The inner chamber is under negative pressure and the mix of filtered air and any air borne contaminants generated by the procedure are evacuated to an air handling unit where contaminants are neutralized and removed from the air. A portion of the top side of the bag is made of a relatively stiff, optically transparent, material through which the surgeon or the assembly worker can view the work area.

Abstract: An isolator and method of using it for providing a contamination-free atmosphere in which a surgical procedure can be performed or equipment that is sensitive to environmental contamination can be assembled. The isolator includes an inflatable bag of flexible material through which filtered air is circulated. For use in surgery, a portion of the lower side is made of an elastic surgical drape material to allow a body member upon which a surgical procedure is to be performed to be pulled into the work space of the bag. A portion of the top side of the bag is made of a relatively stiff, optically transparent, material through which the surgeon or the assembly worker can view the work area. A plurality of open-ended sleeves are attached to the bag through which the hands and arms of the surgeon and his assistants or the worker can extend into the work space.

Abstract: An electronic steam humidifier includes a reservoir drawer having boiling electrodes submerged in water provided by a solenoid fill valve energized by a dual reference level current start-up circuit which is responsive to the current flow through the water from an AC source as measured by a current detection circuit. A system operation counter initiates a flush/drain operation after a certain time period of operation to flush mineral deposits from the reservoir through a siphon tube to a drain trough. A current control circuit includes a pulse width modulator connected to a triac for reducing the average current to the boiling electrodes during an overcurrent condition as indicated by a comparator coupled to the current detection circuit. A reservoir interlock mechanism initiates a flush/drain operation when the reservoir drawer assembly is removed for maintenance.

Abstract: Air filtering apparatus includes a filter cell having ionizing and collecting structure, a high voltage power supply and control unit for supplying a high voltage to the filter cell, a separate low voltage power supply unit for supplying operating power to the high voltage power supply unit and a separate probe unit for monitoring the flow of air within a duct in which the filter cell is installed. The high voltage power supply and control unit includes an output transistor in series with a primary winding of a step-up transformer and controlled by an oscillator circuit which is operative to control and limit the output voltage and current and also the current through the output transistor. The probe unit includes a pair of thermistors and a bridge circuit and operates to provide a signal which is independent of variables other than air flow velocity. A modified apparatus is also disclosed, arranged for portable use and arranged for energization from a standard power line with no separate low voltage supply.

Abstract: Air filtering apparatus includes a filter cell having ionizing and collecting structure, a high voltage power supply and control unit for supplying a high voltage to the filter cell, a separate low voltage power supply unit for supplying operating power to the high voltage power supply unit and a separate probe unit for monitoring the flow of air within a duct in which the filter cell is installed. The high voltage power supply and control unit includes an output transistor in series with a primary winding of a step-up transformer and controlled by an oscillator circuit which is operative to control and limit the output voltage and current and also the current through the output transistor. The probe unit includes a pair of thermistors and a bridge circuit and operates to provide a signal which is independent of variables other than air flow velocity. A modified apparatus is also disclosed, arranged for portable use and arranged for energization from a standard power line with no separate low voltage supply.

Abstract: Air filtering apparatus includes a filter cell having ionizing and collecting structure, a high voltage power supply and control unit for supplying a high voltage to the filter cell, a separate low voltage power supply unit for supplying operating power to the high voltage power supply unit and a separate probe unit for monitoring the flow of air within a duct in which the filter cell is installed. The high voltage power supply and control unit includes an output transistor in series with a primary winding of a step-up transformer and controlled by an oscillator circuit which is operative to control and limit the output voltage and current and also the current through the output transistor. The probe unit includes a pair of thermistors and a bridge circuit and operates to provide a signal which is independent of variables other than air flow velocity. A modified apparatus is also disclosed, arranged for portable use and arranged for energization from a standard power line with no separate low voltage supply.

Abstract: A gate valve structure has an expanding valve assembly mounted with the valve chamber comprising a gate (32) and segment (34) which may be laterally expanded. The gate and segment have a plurality of coacting interfitting saw-type teeth (46,48) which define cam surfaces (50,56) to effect expansion of the gate valve assembly. A flexible sleeve (64) is secured about the ports (42,44) in the gate and segment to bridge the gap (58) between the gate (32) and segment (34) upon expansion. A torsion spring (72) urges the gate and segment to a contracted position.

Abstract: A valve seal includes inner and outer concentric seal rings located side by side in a groove with the inner seal ring against the groove inner wall and the outer seal ring against the groove outer wall. Interfitting surfaces are provided on the seal rings to hold them together and prevent longitudinal movement between them. The groove and the seal rings cooperate to hold the seal rings in the groove. One of the seal rings is relatively soft and has good low pressure sealing characteristics while the other seal ring is relatively hard and has good high pressure sealing characteristics.

Abstract: A ball valve seat assembly includes a seat ring for mounting in a ball valve seat pocket and an annular face seal mounts on one end of the seat ring. The resilient annular face seal member is mounted in a groove in the seat member with one end portion exposed to seal against a ball valve member. The annular seal member has an enlarged end portion located in the closed end of the annular groove. An inner wall portion of the seat ring is permanently deformed radially outwardly over the enlarged portion of the seal ring to anchor it in place in the seat ring. Deforming of the inner wall portion is done by swaging the seat ring.