Accumulator.

Accumulator. In such pieces of hydraulic apparatus as hydraulic cranes or hoists, unless the height of the available column of water, or head-pressure, as it is called, is considerable, the necessary amount and constancy of pressure is obtained by means of an accumulator. This usually consists of a dead weight acting by means of a plunger on the water column. Sometimes, however, steam is used to put on the required pressure, in which case the arrangement is called a steam accumulator.—In Electricity, the accumulator is an arrangement by which electrical energy can be stored for a considerable time in some potential form, so as to be used at will for the production of electric currents. See ELECTRICITY.