High energy rate forming machine - with inbuilt piston-return system to speed operation

摘要

The machine has two return pistons, the stems of which pass down through the cross head that carries the working tool. Admission of hydraulic fluid to the system moves these pistons down before the working stroke commences, and this movement compresses the gas in the working cylinder which is led round a circuit to the back end of the working piston which is in a recess. As soon as the piston moves out of the recess, it comes under the full force of the gas and is accelerated downwards to make the working stroke. Bleeding hydraulic fluid from the system then allows the remaining gas to lift the auxiliary pistons which, in turn lift the crosshead to its starting postion. Thus no separate piston and circuit are required for the return stroke, and higher prodn. rates are possible.