Plastic mating dies and metallic holder supports therefor

Claim 1

LIGHT WEIGHT COMPOSITE DROP HAMMER DIES FOR APPLYING LARGE FORCES FOR BENDING A WORKPIECE IN THE FORM OF A LARGE THIN FLAT SHEET OF METAL TO A PREDETERMINED SHAPE OF SUBSTANTIAL CURVATURE COMPRISING A PAIR OF METALLIC HOLDERS RESPECTIVELY ATTACHABLE TO AN ANVIL AND RAM OF A DROP HAMMER AND HAVING CONFRONTING FACES, SAID FACES RESPECTIVELY HAVING SUBSTANTIAL AND DEEP RECESSES WITH SIDEWALLS WHICH CONVERGE SUBSTANTIALLY AWAY FROM SAID FACES, A PAIR OF INSERTABLE AND DETACHALBE BLOCKS OF RIGID MOLDED POLYMERIZED PLATIC RESIN, SAID BLOCKS HAVING TAPERED PORTIONS, RESPECTIVELY SEATED INTERFITTINGLY WITHIN SAID RECESSES AND WHOLLY SUPPORTED TEHREIN AND AGAINST THE SIDEWALLS THEREOF, SAID BLOCKS HAVING INTGERFITTING AND MATCHING MALE AND FEMALE SURFACE PORTIONS FOR ENGAGING AND FORMING THE WORKPIECE THEREBETWEEN AND CONFORMING TO SAID PREDETERMINED SHAPE OF THE WORKPIECE, SAID BLOCKS HAVING LIGHT WEIGHT RELATIVE TO SID METALLIC HOLDERS AND HAVING SUFFICIENT STRENGTH PER SE TO WITHSTAND AND TRANSMIT TO SAID HOLDERS THE STRESSES DEVELOPED BY THE DROP HAMMER ON THE WORKPIECE, SAID BLOCKS RESPECTIVELY HAVING SMOOTH MOLDED SURFACES WHICH CLOSELY MATCH AND INTERFIT WITH THE SURFACES OF SAID RECESSES WHEREBY SAID STRESSES INCIDENT TO THE DROP HAMMER OPERATION ARE TRANS-