摘要 |
1,202,897. Gas turbine plant. ROLLSROYCE Ltd. May 20, 1968 [May 24, 1967], No.24031/67. Heading F1G. A gas turbine type starter unit 37, Fig. 1 mounted within the fuselage 38 of an aircraft has closure means to close off the air intake duct 40 to the unit compressor 41 simultaneously with unit shut-down so as to reduce fire risk. The closure means may be a ring 48 controlled by solenoids 49 so as to move axially to open or close the intake 40 simultaneously with movement of levers 49a into the start or stop positions, respectively. The closure means prevents fuel vapour from entering the intake 40 of the still hot shut-down unit and exploding. A pivoted plate 47 similarly closes off the outlet duct 45. Lagging 46 prevents any fuel vapour from contacting the hot exterior of the unit. In a modification, Fig. 2 (not shown), the intake closure means comprises an angularly rotatable ring (48a) having spaced apertures (40a) co-operating with similar apertures (40b) in the intake. In a further modification Fig. 4, in which the intake 51 is tubular, the closure means is a disc 50 which can be pivoted between the full and broken line positions by a solenoid 53. In another modification, Fig. 5 (not shown), disc 50 is divided into two halves (50a, b) hinged together (at 54) and pivotally moved by linkwork. In all arrangements the solenoid actuators can be replaced by ball screw and nut mechanisms or rams. |