Hydraulic blanking press

Claim 1

IN A HYDRAULIC PRESS HAVING A FIXED DIE SURROUNDING A SHIFTABLE DIE CUSHION AND A MOVABLE PUNCH SURROUNDED BY A RELATIVELY SHIFTABLE CLAMPING PLATE, THE COMBINATION COMPRISING A CUSHION RAM FOR HOLDING SAID CUSHION LEVEL WITH SAID DIE, A DOUBLE-ACTING MAIN RAM FOR DRIVING SAID PUNCH TOWARD SAID FIXED DIE, A CLAMPING RAM CARRIED BY SAID MAIN RAM FOR URGING SAID CLAMPING PLATE TOWARDS SAID FIXED DIE, A LOW-PRESSURE, HIGH-VOLUME SOURCE OF FLUID UNDER PRESSURE, A HIGH-PRESSURE SOURCE OF FLUID UNDER PRESSURE, MEANS FOR DIRECTING FLUID FROM SAID HIGH-PRESSURE SOURCE TO SAID CLAMPING RAM AT A PREDETERMINED PRESSURE, MEANS INCLUDING A FIRST VALVE ELEMENT FOR DIRECTING FLUID FROM SAID HIGH PRESSURE SOURCE TO SAID CUSHION RAM, MEANS INCLUDING A SECOND VALVE ELEMENT FOR THEREAFTER DIRECTING FLUID FROM SAID LOW-PRESSURE SOURCE TO SAID MAIN RAM TO RAPIDLY DRIVE SAID PUNCH AND SAID CLAMPING PLATE TOWARD SAID DIE, MEANS INCLUDING A THIRD VALVE ELEMENT FOR DIRECTING FLUID FROM SAID HIGH-PRESSURE SOURCE TO SAID MAIN RAM AS SAID PUCNCH REACHES THE STOCK SO AS TO DRIVE THE PUNCH INTO THE STOCK AGAINST THE RESISTANCE OF SAID CUSHION RAM, MEANS INCLUDING FOURTH AND FIFTH VALVE ELE-