Patent GB-128253-A (GB)
Title: Improvements in Carburettors.
IPC: F02D9/00
Filed: 1917-07-03
Abstract: 128,253. Booth, J. B. S., and Lanston Monotype Cerporation. July 3, 1917. Fluid governors; fluid relays; transmitting-mechanism.-The air inlet and mixture outlet of a carburettor are controlled by mechanism connected to a moving part of the engine of an automobile in such a manner as to develop and maintain under varying loads an engine speed dictated by a device adapted to be set by the driver. The valve A, Fig. 1, controls air entering at g and passing over the fuel nozzle G, and is connected through rods A<2>, C<1> and lever A<1> to a piston C. The valve B controls the mixture outlet and is connected, through rods B<2>, D<1> and lever B' to a. piston D. The pistons C, D work in cylinders c, d which are formed in a casing E<1>, which contains a pump E driven through gearing e' from the engine. The speed at which the engine is to run is determined by the position of a valve F which forms an outlet from the cylinder d and is set by the driver. When running, the pump E forces liquid under and raises the piston C, thus opening the valve A and allowing an increasing quantity of air to pass over the nozzle G. This would soon result in an excessive speed being reached by the engine, but, as the piston C is raised, fluid escapes past a cutaway portion c<2> into the conduit E<2> and under the piston D which is also raised and closes the valve B so as to bring the engine speed to that dictated by the position of the valve F. Should the speed fall below this, the piston D falls and the valve B is opened. The movement of the valve B is therefore dependent upon the amount of fluid pumped into the cylinder d being greater or less than that which can escape past the valve F. In a modified construction, the lever A<1>, instead of being pivoted to a fixed fulcrum, is pivoted to the lever B' so that movement of the piston d and valve B causes the lever A to turn about the joint a<2> as fulcrum and therefore varies the position of the valve A. In a further modification shown in Figs. 6, 7, and 8, the valves A, B are in the form of rotating segments in a casing G<10> and surround the fuel nozzle G, the air inlet being shown at g. The valves A, B are secured respectively to coaxial shafts A", B<11>, Fig. 8. The piston C actuates, through an arm c<10>, a sleeve C<20> loosely mounted on the shaft A<11> and carrying on an arm C<50> a stop C<80> in the path of one arm of a lever A<20> which is secured to the shaft A<11>, and is loaded by a spring A<50>. The other arm is connected, through links A<40>, A<10> with the stop C<30>, and, through the links, A<40>, B<30>, with a slotted arm on a lever B<20> which is secured to the shaft B", and is connected to the rod d' of the piston D. The movement of the piston C is opposed by a spring C<40> which is stiffer than spring A<50>, and is secured to an arm C<23> which, through links C<25>, C<24> actuates a valve C<22>, Fig. 6, between the cylinders c, d corresponding to the cut-away portion in Fig. 1. The valve F, Fig. 6, which is set by the driver, comprises a conical valve portion f working in conjunction with a seat f<1> forming the outlet from the cylinder D. The spindle f<2> of the valve is screwed into a block f<3> through helical grooves in which is threaded a loading spring f<5> bearing at its upper end against a casing f<4> which slides in the tube f<6> and can be depressed by the driver to vary the load on the valve. This form of valve, owing to the resilient loading, is enabled to adjust itself within limits to the varying pressure of the fluid. On turning the engine, piston c is forced out and rotates sleeves C<20> which causes stop C<30> to be withdrawn from lever A<20> which, under the action of spring A<50> is rotated and opens valves A. B. The movement increases when the engine commences to fire, and would result in an excessive speed, but a point is reached at which the inward movement of piston d is checked and further opening of valves A, B prevented. The speed still increasing, valve A alone is opened, and when the fluid entering cylinder d is in excess of that which can escape by valve F, the piston D moves outwards and moves both valves in a closing direction, the amount of closing being differential on account of the adjustable link B<30>. If the engine speed should exceed that dictated by the driver, the valve B will be moved by the piston D until a passage B<50> registers with a by-pass B<60> through which air is admitted to the induction passage. Mechanism controlling the timing of the ignition may be connected with the carburettor control mechanism.