Hydraulic press ram cushion

Claim 1

IN A RAM TYPE PRESS PROVIDED WITH A DIE AND A DIE PAD ENGAGEABLE WITH THE WORK UPON CLOSING OF THE PRESS, A HYDRAULIC CUSHION FOR SAID DIE PAD INCLUDING AT LEAST ONE HYDRAULIC WORK CYLINDER PROVIDED WITH A RECIPROCABLE PLUNGER THEREIN ARRANGED TO REACT ON SAID DIE PAD FOR APPLYING PRESSURE THERETO FOR HOLDING SAID DIE PAD IN ITS EXTENDED POSITION DURING CLOSING OF THE PRESS, A BOOSTER INCLUDING AN AIR CYLINDER WITH A PISTON THEREIN AND A HYDRAULIC CYLINDER WITH A PISTON THEREIN, THE EFFECTIVE DIAMETER OF THE AIR CYLINDER BEING AT LEAST SEVERAL TIMES THE EFFECTIVE DIAMETER OF THE HYDRAULIC CYLINDER, THE PISTONS OF SAID BOOSTER CYLINDERS BEING CONNECTED SO THAT MOVEMENT OF ONE EFFECTS MOVEMENT OF THE OTHER, A HYDRAULIC PRESSURE LINE CONNECTING SAID WORK CYLINDER TO SAID HYDRAULIC CYLINDER OF THE BOOSTER, AN OIL SUPPLY TANK, MEANS FOR MAINTAINING OIL IN SAID SUPPLY TANK UNDER A PREDETERMINED PRESSURE SUBSTANTIALLY ABOVE ATMOSPHERIC PRESSURE, A HYDRAULIC PRESSURE LINE CONNECTING THE BOOSTER HYDRAULIC CYLINDER AND THE HYDRAULIC WORK CYLINDER TO THE OIL SUPPLY TANK SO THAT OIL IN SAID CYLINDERS IS MAINTAINED UNDER A MINIMUM PRESSURE, A RELIEF VALVE CONNECTED TO SUCH LASTMENTIONED LINE TO ALLOW OIL WHEN UNDER PRESSURE ABOVE THE PRESSURE FOR WHICH THE RELIEF VALVE IS SET TO RETURN TO THE SUPPLY TANK, AND MEANS FOR SUPPLYING AIR UNDER PRESSURE TO SAID BOOSTER AIR CYLINDER WHEREBY THE PISTON OF THE BOOSTER HYDRAULIC CYLINDER INCREASES THE PRESSURE ON THE OIL IN SAID WORK CYLINDER SUBSTANTIALLY ABOVE THAT AT WHICH IT IS MAINTAINED BY PRESSURE IN SAID OIL SUPPLY TANK.