Patent GB-795434-A (GB)
Title: Improvements relating to turbo-propeller engine fuel control apparatus
IPC: B64D47/00
Filed: 1956-09-26
Abstract: 795,434. Gas turbine plant. WILLIAMSON, E. (General Motors Corporation). Sept. 26, 1956, No. 29378/56. Class 110 (3). [Also in Group XXXIII] A trubo-propeller engine fuel control apparatus comprises a throttle lever by which a given fuel flow to the engine may be set by a fuel valve, an engine speed senser, a compresser inlet temperature senser, a lever pivotable about its fulcrum by one senser and having that fulcrum movable by the other senser, a cam rotatable by the resultant movement of the lever by the sensers and a cam follower which corrects the fuel valve setting in accordance with the movement of the cam. A control lever 90 simultaneously sets a blade pitch mechanism G and a cam 93 adapted to rock a lever 99 linked to a lever 102 of which the other end engages a fuel control rod 40 which turns a lever 41 having a floating fulcrum 42, movement of the lever rocking a second lever 44 to actuate a fuel valve V urged to open by a spring 48. During idling, the lever 102 is locked against movement by fixed pins 108 engaging a cam thereon. To avoid excessive temperature the setting of the valve is modified by a speed senser A, a compressor inlet temperature senser B, compressor inlet and outlet pressure sensers C, E or a fuel density senser D. On increase of compressor inlet temperature the senser B draws down a rod 30 carrying a yielding connection to the pivot 103 of the lever 102, the setting of which above the idling position frees its cam from the pins 108. The rod 30 also rocks a lever 31 whose other end moves a rod 33 carrying the fulcra 15, 28 of levers 14, 26 associated with the speed senser A. Increased speed actuates the senser A to draw down a rod 10 which rocks a lever 11 having its other end connected by a rod 13 to one end of the lever 14; the free end of this lever 14 carries a rod 16 provided with racks 17, 18 which rotate cams 21, 22, the former acting through a lever 25 to actuate the fuel control rod 40 and the latter through the lever 26 to check excessive movement when more fuel is called for. The rod 40 acts through a lever 44, the fulcrum 45 of which is carried by a rod 63 movable by a lever 61 rocked by the fuel density of senser D about a fulcrum 62; the fulcrum 62 is adjustable, being carried by a rod 111a on a lever 110 actuated by a speed setting cam 94 linked to the control lever 90. The rod 111a also carries a fulcrum 82 for a lever 81 actuated by the compressor outlet pressure senser E and adapted through levers 78, 75 to turn a cam 84 about a fixed pivot 84a. A lever 71 having a movable fulcrum 72 carried by the rod 13 is pressed into engagement with the dam 84 by a spring 71a and displaces the fuel control rod 40 as the senser E rotates the cam, thus compensating for inefficient working of the compressor. During idling the position of the cam 84 prevents the lever 71 from reducing fuel flow in response to the senser E. The fulcrum 76 of the lever 75 is adjustable being carried by a rod 50 on which the floating fulcrum 42 of the lever 41 is mounted, the rod being actuated by the compressor inlet pressure senser C. If the speed falls off seriously, the rod 10 actuates a lever 120 to excite a burner igniter 127.