862 



HYDRAULIC MACHINERY, FOR MINES 



cylinder ; g, main cylinder ; h, charging-pump ; j, valve-boxes ; k, pipo from charging- 

 pump to accumulator ; I, accumulator ; in, weight-box ; n, wutor-ci stern in connection 

 with charging-pump ; o, valve gear ; A, small lever forming part of valvo gear ; r, 

 pressure main, between accumulator and hydraulic engine ; s, relief valve. 



In these arrangements, intensity of pressure takes the place of magnitude of volume, 

 and the power assumes a form susceptible of unlimited distribution and division, and 

 is capable of being utilised by small and compact machines. The writer has recently 

 applied engines fitted with two cylinders, each 1 inch diameter, and 7 inches stroke, 

 to the winding of underground tackles or windlasses. 



Table of Pressure Engines. 



Rotary Engines. Fig. 1192 shows Armstrong's rotary water-pressure engine. It is 

 rendered double-acting by bringing the force to bear four times in the crank-circle. 

 The cylinders are made to oscillate, and the plungers are attached directly to tho 

 crank-pin. A piston is formed at the inner end of the plunger, and water is admitted 

 behind the piston, while the front is placed in communication with the pressure-pipe. 

 A is the pressure-pipe ; B, the exhaust-pipe ; E, governor- valve ; F, o, slide valves for 

 producing admission and emission to and from the cylinder, c, D ; i, pressure-pipe, 

 communicating with the cylinders, c, D, in front of tho piston. The slide-valves 

 derive motion from the oscillatory movements of the cylinders, and are of the ordinary 

 D-shape pattern. 



The engine, jig. 1193, is in use at the Wildberg Mines, in Prussia, for winding 



1193 



stuff from the 90 to the 50 fathom level. 

 crank, and three slide-valves. 



It consists of three ram?, a three-throw 



