MAKING AN ENGINE OF SHEET STEEL PRESSINGS.
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A Resume of Recently Published Patent Specifications.
The economy which may be effected in many chassis details by more extensive use of steel pressings has frequently been urged. The most enthusiastic admirer of pressed steel parts, however, would hardly suggest the making of a complete engine of such comparatively fragile material. Such a method of construction, however, is suggested and patented by A. W. Wall in a group of specifications, Nos. 122,447 to 122,452.
The cylinders and crankcase are made, as will be gatnered by reference to our illustrations, from a pair of pressings, bolted together, the joint being in the vertical plane in the axis of the cylinders and extending from front to rear of the engine. A liner is incorporated to form the actual wearing surface of the cylinder, and a third pressing serves as the cylinder head. By further reference to the drawings, the reader will note that a two-stroke engine is the type which the inventor has in mind. The piston. is composed of three cup-shaped pressings, two are placed base to base, the junction being in the axis of the gudgeon pin, and
the bases of these cups .0.1,0 formed so that when joined a hollow cylinder occupies the rnirldle.of The plane of junction. A third cup, base upwards, is inserted into the open end of the upper of the two cups already named, and secured by the beading over of the edgenaf the containing cup.
The connecting rod is formed in one with the gudgeon pin. It is made of two pressings, which are placed back to back, 052
the joint occupying the same position as the web of the usual H-section DOM',anent. The small end fits within the hollow cylinder already referred to-. as being in the piston, audit takes a bearing therein.
The crankshaft is a particularly inter
,citing and ingenious piece of work. It is built up of several separate parts, the method apparently being that of taking a flange and forcing the centre out BO as to form a short projecting tubular piece. The end of this short tube is castellated or serrated, so that it engages with a similarly prepared end of a second piece of the shaft. The crankpins are similarly formed out of other discs, and the flywheel itself is a disc, flanged on its outer circumference so, as to retain a casting which gives it the required
mass. Means of uniting the various segments of the crankshaft are described in the specification: Another ingenious feature of the invention is that relating to the method of driving the magneto. A gearwheel is carried upon one of the engine crankpins, and this engages with another of equal dimensions, the shaft upon which the latter is keyed being carried within the crankshaft, projecting through it to the exterior of the crankcase so that it may conveniently be used for driving the magneto. As the pinion upon the crank is fixed thereto, and incapable of rotation, it will be realized that the magneto armature is driven at twice the speed of the crankshaft.
Other Patents of Interest.
Another ingenious attempt locally to strengthen a Ford chassis thus making it, capable of carrying loads somewhat heavier than those for which it was originally designed, is embodied in speci
fication No. 122,980, by Cl. A. Dur.half. A ball bearing is slipped over each end of the axle casing, its outer race being carried by a housing bolted inside the brake drum on the rear axle.
G. Holt Thomas, in No. 122,907, gives a poppet valve an intermittent rotation, always in the same direction, by fitting two coil springs round the valve spindle.
The Dunlop Rubber Co. has patentedi. in No. 122,904, an improved section of solid tyre, the object being to maintain non-skid properties throughout its life. Mr. Torkington's semi-rigid container for high pressure gases is 'described in specification No. 122,968.
The Austin Motor Co., in No. 122,746, describe a convenient construction of bolts for connecting flywheels to crankshafts, or for other similar joints.
In No. 122,760 the Rudge-Whitworth Co. patent an improved method oi securing discs to wire wheels. No. 122,772, by Wolseley Motors, Ltd.. describes how the cooling of a cylinder is impoved by incorporating a thin liner of metal having high conductivity an the • outside of the working cylinder, No. 122,800, by Rolls-Royce, Ltd., is an improved reducing gear as between engine and propeller of an aeroplane.