Improvements in Hydraulic Presses

24,397. Leeming, J., and Greenhalgh, A. Nov. 25. Hydraulic presses. -A series of valves are placed between the main and the hydraulic press, and so arranged that after the water is once turned on to the intensifier, the press cylinder is first filled at the initial pressure, then the pressure is raised to the normal or main pressure, and finally is raised to the maximum pressure, all these steps being performed automatically and without any water being run to waste from the intensifier. Fig. 1 shows a sectional elevation of the arrangement. Valves e, f are operated by hydraulic plungers a', b for directing the water from the main i to the intensifier g or press h. Water flows from the main i through the valves in the casing j and into the smaller ram k of the intensifier, so forcing water from the intensifier g, through the valves in the casing m, into the press cylinder h to fill up the press, and at the same time to raise the pressure in it. The water then actuates the plunger a' and thus the valve e, so turning the pressure in the main on to the large ram l of the intensifier through the valves in the casing n, and simultaneously raising the pressure in the pressure cylinder to that in the main. The pressure on the large ram of the intensifier causes a greater pressure in the small ram k, and the pressure in the ram cylinder causes the valve f to open through the plunger b so that the water at the intensified pressure can pass through the valve f and the valves in the casing o to the cylinder h. When the press ram h' has been released by running out the water from the cylinder and the releasing- stop has been closed and the pressure stop opened, the intensified pressure falls, and with it the pressure generating it. Both the valves e, f being closed, the water in the main is allowed to flow as at first. The rods a , b are lowered by weighted levers or springs. The valve f is provided with a bypass f , as shown in Figs. 6 and 7, to allow of easy opening of the valve against the intensified pressure. A disclaiming reference is made to Specification No. 13,421, A.D. 1894.