Month in the Patent Office: A Selection of the More Important Aircraft and Engine Specifications Published Recently

In a compression‐ignition engine of the type in which substantially the whole of the air charge is forced into a spherical offset combustion chamber F during the compression stroke, the fuel is discharged by an injector H in a compact stream which passes through the centre of the chamber and impinges on an uncooled plug G, which forms the lower portion of the combustion chamber, at a spot adjacent to a tapering passage G4 through which the air is forced tangentially into the chamber; the circumferential portions of the rotating air charge are thus brought progressively into contact with the fuel spray as it impinges on the plug so that the air and fuel are thoroughly mixed immediately before the charge reaches the inner end of the passage G4, and the tendency for unconsumed air to be driven out of the chamber is reduced. No fuel is injected directly into the end of the passage. The passage may be of circular cross section throughout, or it may change to a crescent or kidney shape towards its inner end, the area of the latter end being preferably three‐fifths that at the outer. Instead of the passage traversing the plug, it may be formed by a groove cut in the outer cylindrical surface of the plug, the direction of rotation of the charge thus being opposite to that obtaining in Fig. 1. The plug G is made of a heat‐resisting metal of low heat conductivity; it is fitted loosely in the mouth of a water‐cooled pocket so that it is surrounded by a heat insulating air‐space F1. A retaining ring G2 may be optionally provided, the off‐set of the plug ensuring sufficient overlap between the cylinder end and plug to retain the latter if the ring is omitted. In the modified construction shown in Fig. 3, the upper portion of the combustion chamber is provided with a liner K which is insulated from the water‐cooled pocket by an air gap; the liner is supported by an integral boss K1 which passes through a bore in the wall of the pocket and is secured by a ring K2. An electrically heated hot wire J is employed at starting. The injector socket passes through the water jacket chamber of the cylinder head to ensure adequate cooling. Specification 371,025 is referred to.