Patent GB-697393-A (GB)
Title: Acceleration control means for continuous combustion turbine engines
Inventor: SIMMONS HAROLD CUTHBERT
Filed: 1950-04-28
Abstract: 697,393. Gas turbine plant. DOWTY EQUIPMENT, Ltd. April 26, 1951 [April 28, 1950],'No. 10537/50. Class 110(iii) [Also in Group XXIX] A gas turbine fuel system comprises a throttle control member which operates through a resilient connection upon a main throttle connected to a dashpot to limit its rate of opening, an auxiliary throttle which is movable conjointly with the main throttle so as to augment, in a predetermined proportion, the flow through the main throttle and a valve controlling the flow through the auxiliary throttle which is operated by means responsive to initial relative displacement in the resilient connection between the control member and the main throttle which closes the valve when there is no relative displacement and opens the valve when relative displacement occurs arising from rapid movement of the control member to open the main throttle. The fuel system shown comprises a fuel inlet conduit 12 which leads through a main throttle 11 and an auxiliary throttle 15 arranged in parallel to the delivery conduit 13 to the burners. The throttles 11, 15 are controlled by a common throttle element 18 and are so arranged that the throttle 15 only passes about 10 per cent of the fuel passed by the throttle 11. The conduit 14 leading to the throttle 15 is opened and closed by valve 16. The throttle element 18 is operated through a rack and quadrant 19, 20 by a lever 21 connected to a control member 26 by a spring 27 and to a slotted plate 28, pivoted on the same axis as the member 26, by a connecting rod 29. The element 18 is connected with a dashpot device 22 by a spring 23. When the element 18 is moved to open the throttles 11, 15 there is positive engagement between the element 18 and the piston rod 24 of the dashpot 22 but when the element is moved to close the throttles, the spring 23 is stretched and the piston 25 moves slowly until it abuts against the element 18. A cam 30 slidable lengthwise of the control member 26 has a pin 31 engaging a slot 32 in the plate 28. When the engine is not accelerating, the member 26 will, in relation to the plate 28 occupy the position shown in dotted lines with the pin 31 at the right hand end of the slot 32. In this position the cam 30 is at its lowest position and the valve 16 is closed and only the main throttle 11 is in operation. If the pilot moves the lever 26 slowly in an anti-clockwise direction the friction in the system will cause the lever 21 to move correspondingly. If the lever 26 is moved quickly in the same direction, the resistance caused by the dashpot 22 will cause the pin 31 to ride up the inclined part of the slot 32 into the position shown and cause the cam 30 to open the valve 16 so that both the throttles 11, 15 will be in operation. At the same time the spring 27 will be put into tension. The tension in the spring 27 will gradually be released by the action of the dashpot 22 which will also allow the throttle element to move at a controlled rate. The resulting movement of the lever 21 will rotate the plate 28 until the pin 31 is again at the right hand end of the slot 32. The cam 30 then returns to its original position and the valve 16 is again closed. Specification 639,987, [Group XXIX], is referred to.