Abstract: A turbine shroud assembly includes forward and aft hangers, an axisymmetric plenum assembly, ceramic shroud segments, ceramic spacers, and forward and aft rope seals. The plenum assembly supplies impingement cooling to the shroud and the hangers. The impingement cooling to the forward and aft hangers is controlled independently to improve blade tip clearance. The rope seals are radially inward from the hangers and reduce cooling flow leakage. The turbine shroud assembly can operate in a higher temperature environment using less cooling flow than the prior art.

Abstract: A foil bearing assembly for use in a gas turbine engine is provided. The assembly includes an annular bearing carrier mounted to the housing of the engine. An annular foil carrier disposed within the bearing carrier and carrying a plurality of overlapping foils that engage an outer surface of a journal. The journal is mounted to the rotating assembly of the engine to define a cavity. Disposed in the cavity is a showerhead having an inlet for receiving a flow of cooling air and a plurality of orifices for providing impingement cooling of the inner surface of the journal. The use of a showerhead in a thrust foil bearing is also disclosed.

Abstract: This dual voltage transformer comprises a primary winding having a tap at a location intermediate its length, a first termination for connection to line voltage, and a second termination for connection to ground. When the transformer is to be operated at a relatively high voltage, the first termination is connected through a dual voltage switch to line voltage; and when the transformer is to be operated at a relatively low voltage, the tap is connected through said switch to line voltage. First varistor means is connected across the primary winding between said first and second terminations both when the transformer is operated at high voltage and at low voltage; and second varistor means having a lower breakover voltage than the first varistor means is connected between said tap and ground when the transformer is operated at low voltage.

Abstract: In a packet switched multiplexed data/voice communication system, timed loopbacks along a subscriber line are effected by purposely extinguishing or killing the DATA carrier sewing the line.