Scientific American Supplement, No. 458, October 11, 1884 (Paperback)

Excerpt: ...was, however, illustrated by its application to a large express goods (freight) engine, built by the London and North-Western Railway Company (England) specially to test the advantages and the endurance of the gear. This engine had cylinders of 18 inches in diameter and 24 inch stroke, and six wheels coupled 5 feet 1 inch diameter, and was designed by Mr. Webb, the Company's chief engineer, for their heavy fast goods traffic on the main line. The engine has been running this class of traffic ever since. In January, 1884, it was passed through the repair shops for a general overhauling, when it was found that the valve motion was in such good condition as to be put back on the engine without any repairs. The main object of this present paper is to deal with the advantages of the valve gear and its application to various classes of engines both on land and at sea, and with the results of such applications, rather than treating it as a novelty, to give an exhaustive description of its construction and functions, which was done in the paper above referred to. A very short description of its action and main features will, however, be necessary to the completeness of the paper, and as a basis from which the improved results to be recorded should necessarily be shown to spring. The essential feature of this valve gear is that movement for the valve is produced by a combination of two motions at right angles to each other; and by the various proportions in which these are combined, and by the positions in which the moving parts are set with regard to each other, it gives both the reversal of motion and the various degrees of expansion required. Eccentrics are entirely dispensed with and the time-honored link gear abandoned, the motion is taken direct from the connecting rod, and by utilizing independently the backward and forward action of the rod, due to the reciprocation of the piston, and combining this with the vibrating action of the rod, a movement...