Appleton's Dictionary of Machines, Mechanics, Engine Work, and Engineering Volume 1

by Books Group

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1857 ...combination obviates the necessity of throwing the engines out of geer at all; and full speed ahead may be changed instantaneously into full speed intern, and without stopping the engines. Messrs. Rennie have introduced this species of starting-geer into the Samson and some other steam vessels with the most satisfactory results; and it appears likely to become general, at least in valves where there is little lap. In our plates of details the valve is moved by means of a lever, and the eccentric-rod is thrown out of geer by means of a pulley on the end of a lever, which, when raised, forces the pulley against the under side of the rod and lifts it out of tho notch. The act of raising this pulley depresses another pulley on a lever fixed upon the same shaft, and enables another rod in connection with the starting-handle to fall into geer, the intention being, that when the eccentric-rod is in geer, the starting-handle shall be without motion, as its swinging would be inconvenient and dangerous if worked by the engine. This plan of preventing the starting-handle and the eccentric-rod from being in geer at the same time has now come into general use. The method adopted by Napier in the Precursor is a very elegant it consists in the use of an eccentric-stud for supporting the lever which carries the roller; and the act of moving this lever, so as to enable the eccentric-rod to fall into geer, draws back the pinion of the starting-shaft out of the 6ector, with which it is engaged. Instead of a lever, the starting-shaft in this case is moved by a wheel similar to a steering wheel of a ship. Brine-pumps, --Pumps for changing the water in marine engine boilers, so as to prevent the salt water from reaching an inconvenient degree of saturation, were first applie..

662 pages, Paperback

First published January 1, 1850