The blower casing D has on either side circumferentially flanged rings N, which are a running fit in circular register slots provided in the annular casing L and its cover plate P, in order to provide a gas-tight joint between the opposite revolving casings D and L. Fan blades Q are also provided in the casing L to accelerate still further the incoming gas. The arrangement of the two sets of blades is made clear in the sectional sketch (Fig. 64). It will be realized that by means of this compound blower device a considerable pressure can be attained.
The crankshaft is drilled to provide a feed for the gasoline, which is atomized by a device R in the large central opening of the blower casing D by means of pressure fed from the annular casing L through suitable leads S.
As each piston nears the bottom of its stroke, exhaust ports T, provided with expansion cones for the purpose of increasing the velocity of the exhaust gases, are opened. The inlet port M is then uncovered, and the compressed charge rushes into the combustion chamber.
The general design of the engine is made plain by Fig. 63, but there is one other point to which reference should be made, and that is the provision of rings V, one on either side of the cylinders, to enhance the strength of the construction.
Although the difficulty of compression appears to have been cleverly tackled in this invention, the possibility of the compressed mixture in the inlet casing and blower becoming ignited at the moment of admission by a residue of exhaust gas in the combustion chamber still exists. However, the effect of such a backfire should not prove quite so serious as in some designs. Apart from other considerations, owing to the large area of the blower intake, such an occurrence should merely have a more or less elastic braking effect.
(60) Gnome Radial Two Stroke Motor.
The builders of the famous Gnome four stroke cycle rotary motor, Sequin Frères, have recently developed a radial two stroke cycle motor that bids fair to supplant their original type. Referring to the diagrammatic cross-sections which show only a single cylinder unit, a very long tubular piston will be seen that is divided into two independent chambers, A and B. Both chambers are placed in communication with the outside space, C and D.
The upper end of the piston is continued above the top division head of the chamber A, and the extension is provided with the slot F. Near the center of the piston, the walls of the piston are run out into a flat circular plate or trunk piston E, which is the actual piston head that receives the force of the explosion. The piston E reciprocates in the large cylinder H, which is reduced at its upper end to the diameter of the main piston barrel, for which it affords a sliding support, or guide, and also serves to aid the exhaust port closure. The lower end of the cylinder H is enlarged in diameter as shown by K so that a clear annular space is left between the cylinder walls and the piston head E, when the latter is at the bottom of the stroke. The cylinder diameter is then reduced to the diameter of the main piston barrel.
The motor operates as follows:
Suppose the piston to be ascending (Fig. 1), compressing the mixture above the piston head in the cylinder E, and at the same time the volume of the space M, below E, is being increased until the piston reaches the position shown in Fig. 2.