Abstract: A fuel control system for a gas turbine engine having a plurality of burner manifolds, comprising a spill valve for spilling excess fuel from a high pressure fuel supply line and a plurality of control arrangements, each of which is arranged to control fuel flow rate to a respective one of the manifolds and comprises a metering valve and a regulator for regulating the pressure drop across the metering valve, the spill valve having a cylinder containing a piston which is movable to close the spill valve and each of the regulators having a valve for connecting the cylinder of the spill valve to high pressure fuel when the pressure drop across the metering valve is less than a predetermined value.

Abstract: Disclosed is a digital correction system for application to an analog parameter measurement transducer. A temperature sensor, either separate from or incorporated into a parameter measurement transducer provides a temperature signal which is converted by an A-to-D converter to address temperature gain and offset corrections. These corrections are applied to a preamplifier amplifying the output of the transducer. The preamplifier output which has been temperature gain and offset corrected, is applied as an input to a final stage amplifier and also to a further A-to-D converter which addresses a storage device including transducer gain and offset corrections. The transducer gain and offset corrections are applied to the final stage amplifier so that the analog sensor output is corrected for temperature effects and for transducer nonlinearities.

Abstract: Disclosed is the backlit display and/or backlit keyboard display which have a controlled level of illumination at the surface thereof. Where such switch and/or display are illuminated by a light emitting diode, the present invention interposes an optical filter between the light emitting diode and the surface of the cover. The optical filter contains a pattern thereon having a variable density distribution of opaque material which in a preferred embodiment is densest in the area closest to the light emitting diode and decreases in density in areas away from the light emitting diode. In a preferred embodiment the optical filter is a "negative" of the illumination without a filter present. The result in both the switch and display embodiments is a substantially constant level of illumination across the surface of the cover. Further disclosed is at least one slot in translucent layers which may be incorporated in a switch or display which reduces "crosstalk" between switches and/or displays.

Abstract: A permanent magnet brushless torque actuator is comprised of an electromagnetic core capable of generating an elongated toroidally shaped magnet flux field when energized. Outside the generally cylindrical coil is an outer housing with upper and lower end plates at each end. Mounted to the end plates and extending towards each other are stator pole pieces separated from its opposing pole piece by an air gap. A permanent magnet rotor is disposed in the air gap and mounted on a shaft which in turn is rotatably mounted in each of the end plates. The permanent magnet rotor comprises at least two permanent magnets, each covering an arcuate portion of the rotor and having opposite polarities. Energization of the coil with current in one direction magnetizes the pole pieces such that each of the two pole pieces attracts one of the magnets of the rotor and repels the other magnet of the rotor resulting in a torque generated by the output shaft.

Abstract: A switch assembly comprising a housing, a rigid operating member mounted for movement relative to the housing and accessible to an operator, an electrical contact operable by movement of the operating member from a rest position to an operative position relative to the housing, a flexible seal between the operating member and the electrical contact and capable of transmitting operative movement of the operating member to the contact while preventing passage of moisture and other contaminants from the region of the operating member to the contact, and, a limit preventing movement of the operating member relative to the contact beyond the position at which the contact is operated. The switch can include further operating members and associated contacts and limits carried by the housing and if desired the assembly can incorporate a heater for heating the operating member region of the assembly.

Abstract: A stator of a rotary electric machine is supported in a housing structure and is secured therein against relative rotation or axial movement by angularly spaced fasteners. A circumferential passage in the stator communicates with a supply passage for liquid coolant. The temperature coefficients of expansion of the materials of the housing and the stator differ so that below a predetermined temperature those parts are an interference fit, and above that temperature channels are created between the fasteners, through which channels coolant can flow axially from the passage.

Abstract: A system for controlling flow of fluid along a conduit from a source of fluid under pressure to a consumer device comprises a primary throttle for connection in the conduit and controllable between a first condition in which it is at least partially closed and a second condition in which it is more fully open, and a secondary throttle defining at least one orifice for connection in the conduit and including a member which is displaceable to vary the area of the orifice. A first force dependent upon the pressure drop across the secondary throttle and a second force dependent upon the time integral of the pressure drop across the primary throttle are applied to the member, the first and second forces being oppositely directed, whereby the member is displaced towards a position in which the pressure drop across the secondary throttle bears a predetermined relationship to the time integral of the pressure drop across the secondary throttle.