GB106653A - - Google Patents

Abstract

106,653. Parsons, P. R., Clift, C. E., and Manganese Bronze & Brass Co. May 26, 1916. Presses, producing part of stroke of, hydraulically.-Hydraulic presses for the extrusion of metals and for like purposes are supplied by a set of pumps driven from an internal-combustion en. gine through a motor-generator fly-wheel set, the connexions and control being such that the non- effective part of the stroke takes place at relative. ly low pressure, and the effective part at high pressures varying according to the power required. The press consists of a main cylinder f and an auxiliary cylinder a, the ram of which is connected by a cross-head b and rods c, c<1> to the cross-head d of the main ram e. The main cylinder f is connected to the low-pressure supply tank through a non-return valve h, pipe i', and valve m. The main supply pipe k<1> from the pumps is provided with valves k, i for controlling the supply to the cylinders a, f and the retracting-cylinders g. The pumps are driven by a motor-generator iiy-wheel set of the Ilgner type. When the press is not working, the valves k, l, m are open, and water is circulated through the supply tank. By closing the valves i, m, water is supplied to the cylinders a, g, so that the ram is brought quickly up to its work, the area of the piston in the cylinder a being greater than the area of those in the cylinders g. During this movement, the cylinder f draws in water through the valve h from the tank. The valve l is then opened, so that pressure water is admitted to the cylinder f for the final portion of the stroke. At the end of the stroke, the valve m is opened and the valve k closed, so that the cylinders g only are under pressure, and the ram is retracted. No hydraulic accumulator is used in the system.