expansion gear

Steam-engine: The apparatus by which acce of steam to the cylinder is cut off at a given part of the stroke; a cut-off. A variable cut-off is one which is capable of being adjusted while the engine is in motion, to cut off at any given portion of the stroke, within a given range, as the requirements of the work may indicate. A fixed expansion is one arranged to cut off at a determinate part of the stroke. An automatic expansion is one which is regulated by the governor, and varies with the amount of power required. [EXPANSION-VALVE.] IMG:content-1271.png:[blocks in formation]