Patent GB-239657-A (GB)
Title: Arrangement for the improved working of internal combustion engines, in particular transport and aircraft motors, with alternative pressure and suction air supply to thecarburettor
IPC: F02D29/04
Filed: 1924-07-25
Abstract: 239,657. Daimler, P., and Linck, F. July 25,1924. Spray carburettors. - In an engine adapted to work alternatively with suction or pressure air supply, and provided with means under the control of the driver for changing over quickly from one system to the other, the induction pipe 1 into which the fuel nozzle 4 discharges, is provided with a suctionactuated air valve 14 adapted to close when pressure air is supplied by a compressor 18 and the float chamber 5 and an auxiliary tank 8 at a higher level are connected by pipes 12, 10, 11 with the induction pipe. The fuel tanks ara therefore subjected either to the pressure of the surrounding air or to the pressure of the cornpressor. A valve 32 at the entrance to the pipe 12 is held open bv a spring and only closes in the event of a back fire. A regulating valve 17 may be placed on either the inlet or delivery side of the compressor. The auxiliary tank 8 is fed with fuol from the main tank 19 at a lower level by air pressure produced by a pump 22 provided with a safety valve 24. It may also be filled independently through a cock 25. A small tube near the seat of the valve 14 serves as a drain for excess fuel without appreciable loss of air pressure. In the event of the valve 14 sticking, it mav be released by mechanism actuated from the throttle valve 2 as it approaches its closed position, the mechanism not interfering with the automatic action of the valve. To prevent excessive pressure being produced due to closure of the throttle 2 while the compressor is working the throttle, actuated bv the rod 40, Fig. 3, carries a. stop 39 which, when the throttle is closed, is brought into the path of a stop 38 on a lever 35 adapted to throw the clutch members 33, 33<1> of the compressor 18 into gear. Thus, if the throttle is closed the compressor cannot be driven, and if the compressor is working the throttle cannot be closed. The pipe 20, Fig. 1, supplying the tank 8 is provided with a valve 21 which closes when the pressure in the tank is excessive, e.g. during supercharging. This valve, in a modification, Fig. 4, may be contained in the tank itself and comprises a fixed conical portion 46 adapted to engage the upper of two seats in a part 43 carried by a flexible diaphragm 45. the lower seat being that of the float valve 9. The pipe 10, Fig. 1, enters the chamber 8 below the diaphragm and on the pressure becoming excessive the upper seat is forced against the part 46 and a reversal of flow is prevented. In a modification the valve 14, Fig. 1, is replaced by a butterfly valve actuated by a diaphragm subjected to the pressure in the induction passage. In a modificaton, Fig. 5, the space above the fuel in the float-chamber 5 is in communication with the induction passage 1 through a channel 47 formed in one with the nozzle 4 such channel being provided with a control member 49. The cover 50 carries the inlet pipe 51. In a further modification, the inlet pipe enters the chamber through the side near the top and its discharge is controlled by a valve actuated by a float hinged on a pin located in a slot at the upper edge of the chamber. This allows of the float being withdrawn when the cover is removed.