Hydraulic Press

One of the elementary machines, which consists of two chambers, in each of which fits a plunger, fluid-tight, in a stuffing-box. The two plungers are of different area, and the chambers are connected by a pipe, in which is a valve opening outward from the smaller plunger chamber. If now the two chambers are full of fluid, and the area of the smaller plunger be a umed at one sq. inch, a given pre ure on the free end of that small plunger will produce a fluid pre ure in the ve el of that number of pounds per sq. inch. On the bottom of the larger plunger also this same pre ure per sq. inch will be exerted, and it will be forced outward, unle held back by a pre ure which is as much greater than that on the small plunger as the area of the large plunger is greater than the area of the small one. The smaller is usually a pump plunger; to secure steadine of motion for the resistance three Hydraulic Pre . band being drawn in from outside through a stuffing-box. It is sometimes called Hydrostatic Pre . See BRAMAH PRESS.