Sentence Examples with the word Direct-acting

The engines used for winding or hoisting in collieries are usually direct-acting with a pair of horizontal cylinders coupled directly to the drum shaft.

Mine pumps are of two classes: (I) those in which the driving engine is on the surface and operates the pumps by a long line of rods passing down the shaft, commonly known as the Cornish system; (2) direct-acting pumps, in which the engine and pumping cylinders form a single unit, placed close to the point underground from which the water is to be raised.

It becomes, therefore, necessary to balance in some way the varying displacement of the ram if economy is to be secured in the working: this is often done by the use of counter-weights attached to chains travelling over head sheaves, but this largely destroys the simplicity and safety of the direct-acting lift, and hence some form of hydraulic balancing is more satisfactory and more certain.