Patent GB-984925-A (GB)
Title: Valve device
Inventor: FREEMAN FREDERICK
IPC: F02K1/10
Filed: 1963-02-08
Abstract: 984,925. Valves. ROLLS-ROYCE Ltd. Nov. 28, 1963 [Feb. 8, 1963], No. 5347/63. Heading F2V. [Also in Division F1] The invention relates to a valve device for controlling the flow of fluid through an annular duct and may be applied for example for controlling the flow of air through an annular duct disposed around a gas turbine jet engine. The valve member comprises a plurality of plates which are arranged side by side and are pivoted to each other at their sides so that they form or may be arranged to form, a divergent member of variable apex angle, one end of the valve member being pivotally connected to one wall of the annular duct and there being means for moving the other end of the valve member with respect to the other wall of the annular duct between a closed position in which flow through the annular duct is relatively small or zero and an open position in which such flow is relatively large. In the gas turbine jet engine shown in Fig. 1 an annular duct 17 is disposed around the engine and air may pass into the duct from the air intake 11 through openings which are controlled by flaps 30, the downstream end of the annular duct being controlled by a valve device 20 in accordance with the invention. The valve device comprises a series of flaps 21, 21a disposed side by side and pivotally connected along their adjacent edges as indicated in Figs. 3 and 4, the downstream edges of the flaps 21 being pivotally connected to the downstream end of the outer wall 18 of the annular duct 17. The flaps 21 are connected by means of bell-crank levers 26 to actuating rams 25 so that the valve device can take up the frusto-conical disposition shown in Fig. 1 in full lines in which the flaps 21a abut face to face and the flaps 21 abut edge to edge, or the cylindrical disposition indicated in broken lines in which the upstream edges of all the flaps 21 and 21a are disposed in a circular formation. In the first of these positions the valve member acts to close the annular duct 17 and in the second position the valve member allows air flow through the duct. The upstream edges of the flaps 21, 21a co-operate with the downstream edges of the flaps 21, 21a co-operate with the downstream edges of the flaps 32 of a variable area jet nozzle 31, the nozzle flaps 32 and the flaps 21, 21a of the valve device cooperating when in the position shown in full lines to form a convergent-divergent jet nozzle nozzle suitable for use at supersonic speeds. In a second embodiment, the valve device comprises four flaps 121 and eight flaps 121a disposed side by side and pivotally connected along their edges. The flaps 121 are pivotally connected at their downstream ends to fixed members 41 which constitute an outlet of rectangular section. The inner surfaces of flaps 121 are of arcuate form at their upstream ends and of linear form at their downstream ends so that when the valve device is in the closed position shown in Fig. 6 with the flaps 121a abutting face to face, the flaps 121 define a passage which is of circular form at its upstream end and of rectangular form at its downstream end. When the valve device is in the open position shown in Fig. 7 the flaps 121, 121a define a passage which is of substantially rectangular form throughout its length. The invention is stated to be applicable also to valve members controlling flow through the by-pass passage of a gas turbine jet engine of the by-pass type, and as an adjustable nose cone on the intake to a supersonic engine.