Patent GB-834550-A (GB)
Title: Fuel control system for a jet reaction engine provided with a thrust reversing mechanism
Inventor: COLLEY ROWAN HERBERT
IPC: B64D47/00
Filed: 1955-12-13
Abstract: 834,550. Controlling aircraft. ROLLSROYCE Ltd. Dec. 13, 1956 [Dec. 13, 1955], No. 35824/55. Class 4. In an aircraft engine throttle control mechanism for gas turbine power plant provided with jet-direction reversing mechanism wherein, during landing partial movement of the throttle lever in one direction reduces engine thrust and further movement of the lever in the same direction operates the jet reversing mechanism and then increases engine thrust, the throttle control mechanism comprises a lever 40 movable over a quadrant opening in a casing 42, the lever being fulcrumed on one of two pins 43, 44 which fit into slots 45 and 46 in the side wall of the casing. Intermediate the pivots the lever is connected by link 47 to bell crank lever 48 pivoted at 49 on the casing and formed with a slot 51 and lever 50, having a slot 52. A pin on the end of link 54 fits through both of these slots the link being connected through bell crank 55 to fuel control rod 56. During normal flight lever 40 is movable from the idling position for forward thrust (shown in full line in Fig. 3) to the position shown by dotted line by turning on pivot 43 with pin 44 moving over slot 46. For control during reverse thrust lever 40 is raised so that it can be pivoted about pin 44 with pin 43 moving over slot 45 as shown in Fig. 5. To free the lever for reverse thrust movement a stop 58, co-operating with a shoulder 59 on lever 40 has to be moved by a lever 57 which connects also through linkage 61-64 with a valve 65, Fig. 6, controlling the jet reversing mechanism. A lever 50, which operates the engine fuel cut off cock, may be moved over a quadrant 67 from the free position shown in the figures to the shut-off-position in which catch 68 engages slot 69 whereby pin 53 is baulked in slot 52. A solenoid operated catch 71, mounted on lever 50, co-operates with a stop 72 on link 47 to prevent reverse-thrust power-increase movement of lever 40 until circuits to be described are energised to operate the solenoid 70. Shown in Fig. 6, in which the throttle control positions corresponds to those shown in Fig. 3, rod 56 operates a throttle valve 109 in the fuel line from tank 73, pump 74 and engine burners 75 and rod 64 operates arm III connected to the piston rod of valve 65 which controls the supply of compressed air from the engine through pipe 87 to jacks 90 and 94 through pipes 89, 101 and 92, 97 respectively. The jack 90 operates a valve 85 in the engine jet pipe to divert the propulsive gases through a duct 84 in the nacelle casing, the outer surface of which is provided with a gas-deflecting door 83 operated by jack 94. Operation of lever 40 over the range shown in Fig. 3 operates valve 109 above, but movement of lever 57 to free lever 40 for further movement also operates valve 65 to admit pressure air to jack 94 which opens door 83 and also opens a valve 98 to pass pressure air from pipe 101 to jack 90 to place valve 85 in the gas diverting position, this movement serving also to close a valve 93 in pipe 92 and to close contacts 104, 105 in a circuit with other contacts 108 which are closed when lever 40 is raised. Closing of the contacts operates solenoid 70 to free catch 71 from stop 72. Thereafter further movement of lever 40 will increase engine thrust with forward diversion of the gases through duct 84. In a further embodiment not shown, the lever 40, instead of being raised to pass from forward to rearward thrust positions is movable sideways through a gate to connect with forks on one of two levers pivotally connected by links on opposite sides of the axis of lever 40 to the throttle valve 109.