Hydraulic forging presses

Claim 1

AN ELECTRO-HYDRAULICALLY CONTROLLED HYDRAULIC FORGING PRES, COMPRISING: A PIPE SUPPLYING PRESSURE WATER TO THE PRESS CYLINDER AND PLUNGER, A FIRST PUMP CAPABLE OF SUPPLYING PRESSURE WATER TO THE SAID PRESSURE-WATER SUPPLY PIPE, AT LEAST ONE ADDITIONAL PUMP CAPABLE OF SUPPLYING PRESSURE WATER TO THE SAID PRESSURE-WATER SUPPLY PIPE, A NON-RETURN VALVE INTERPOSED BETWEEN THIS ADDITIONAL PUMP AND THE PRESSURE-WATER SUPPLY PIPE, A MAIN CONTROL INCLUDING ADMISSION VALVES INTERPOSED IN THE PIPING CONNECTING THE PUMPS WITH THE PRESS CYLINDER, AN EXHAUST VALVE FOR EXHAUSTING WATER FROM THE PRESS CYLINDER, AND VALVE-LIFTING ELECTRO-MAGNETS WHICH OPEN THESE VALVES WHEN REQUIRED, A REMOTE CONTROL MEMBER, GEARING ROTATING THE REMOTE CONTROL MEMBER IN ONE DIRECTION OR THE OTHER ACCORDING TO THE DIRECTION IN WHICH THE PLATEN OF THE PRESS IS MOVING, A PHASE-DETECTOR CIRCUIT, SO CONNECTED WITH THE REMOTE CONTROL MEMBER AS TO TRANSMIT CONTROLLING IMPULSES IN ACCORDANCE WITH THE DIRECTION OF ROTATION OF THE REMOTE CONTROL MEMBER, AND A CHANGE-OVER RELAY THE SWITCHING POSITION OF WHICH IS DETERMINED BY THE IMPULSES TRANSMITTED TO IT BY THE PHASE-DETECTOR CIRCUIT, THE CIRCUITS OF THE VALVE-LIFTING ELECTRO-MAGNETS BEING CONTROLLED BY THE CHANGE-OVER RELAY.