Patent GB-711745-A (GB)
Title: Method of and means for regulating internal combustion turbines
Filed: 1952-01-30
Abstract: 711,745. Gas turbine plant. COMPAGNIE ELECTRO-MECANIQUE. Jan. 30. 1952 [Feb. 15, 1951], No. 2481/52. Class 110(3) [Also in Groups XXXI and XXXIV] A gas turbine plant for a vehicle comprising a turbine driving a compressor and a mechanically independent power turbine arranged in series has a by-pass through which the exhaust gases from the compressor turbine may be led to the exhaust of the power turbine, the flow through the by-pass being controlled by a power relay responsive to the pressure of the fuel supplied to the combustion chamber. The plant shown comprises a compressor 2 supplying air to a combustion chamber 3 feeding a compressor driving turbine 4 and an independent output turbine 5. The turbine 5 drives the road wheels 8 through reduction gearing 6, changespeed gearing 9 and bevel gearing 10 and is provided with a by-pass 11 controlled by a valve 12. The valve 12 is controlled by a power relay 14, consisting of a spring loaded piston 15 in a cylinder 16, which is operated by the pressure of the fuel supplied to the combustion chamber 3. The fuel is supplied by an engine driven gear pump 19 the discharge pressure of which is controlled by a device 24. The device 24 comprises a relief valve 25 attached to a piston 26 acted upon by the fuel pressure and a spring 27. The loading of the spring 27 is determined by the position of the throttle pedal 28 acting through linkwork 74. 30, 31 and 33. The pedal 28 is urged towards the position of a minimum fuel pressure by a spring, 34, which position is determined by a cam 36 adjustable by the driver by means of a lever 37. The idling speed of the turbine plant is therefore variable. The cam 36 also varies the loading of a spring 17 of the power relay 14 so that irrespective of the idling speed of the turbine, the valve 12 will open at the fuel pressure corresponding to the idling speed. If the pedal 28 is depressed, the loading of the spring 27 is increased consequently increasing the pressure of the fuel supply to the combustion chamber 3. This increase in fuel pressure will cause the valve 12 to close and combustion gases to be supplied to the useful output turbine 5. To prevent the driver changing gear when the turbine 5 is under power a lever 49 pivoted at 50 is attached at one end to the operating rod 48 of the valve 12 and at the other end has a bent end 55 which may engage in notches 54 of a sector 53 attached to the gear change lever 51. When the valve 12 is closed the end 55 enters one of the notches and prevents further movement of the lever. If the driver should leave, in error, the lever 51 at a dead point, the lever 48 would prevent the valve 12 closing when the pedal 28 is depressed. The rod 48 also actuates a switch 56 which controls a circuit feeding an electric decelerator 57 consisting of a magnetic disc 58 mounted between pole pieces provided with an excitation winding 59. When the valve 12 is opened the switch 56 closes the circuit of the deceleratorwhich then slows down the speed of the turbine 5. A centrifugal switch 71 is provided to open the circuit of the decelerator at low running speeds to reduce the drain on the battery 60. The driving turbine 5 and the turbine-compressor unit 2. 3 mav be provided with speed limiting devices to cut out the fuel supply whenever a predetermined speed is exceeded. In a modification, both the decelerator switch and the gear change lever lock are operated directly by the throttle pedal 28.