Page:Motors and motor-driving (1902).djvu/148

(3) The Spray Carburetter.—The carburetter fitted to the Daimler two-cylinder engine is a good representative of this class. It is depicted in fig. II. The general principle is as follows: The petrol enters the float chamber e through a pipe g. It is then drawn by the suction of the engine along a circular passage, and through the jet h, and impinges against the sloping sides of the carburetter. At the same time air is drawn though the air cylinder d and into the jet chamber through

Fig. II.—The Daimler Carburetter

a, float spindle with valve admitting petrol to float chamber at end; b b, arms actuating the valve a through the float c; c, float' actuated by rise and fall of the petrol in the chamber e; d, air inlet to carburetter; e, float-feed chamber; f, valve which cuts off supply of petrol to the chamber e; g, petrol inlet; h, jet through which the petrol sprays; i, orifice through which the air is drawn from d into the carburetter; j, carburetter; k, tap to admit further supply of air; l and m, passages through which the mixture passes on its way to the induction valves; n, induction valve, shown shut; o, induction valve open; p p, passages through which the petrol passes; r, removable piece against which the spray is ejected; s, chamber through which the air, entering at o, passes on its way to the carburetter.

the aperture i. Here, rushing upward, it mixes with the atomised petrol, and the two are thoroughly mingled in the carburetter, and are thence drawn along the passages l and m to the induction valves, which in turn give admission to the combustion chamber.

The supply of petrol is governed as follows: As it ascends through pipe g into the float chamber e it raises the float c until the petrol has reached a point in the float chamber almost as high as the top of the jet. At this stage the upward move-