Apparatus for making prestressed concrete bodies

Claim 1

APPARATUS FOR MAKING A PRESTRESSED CONCRETE BODY, COMPRISING A MOLD, A WIRE STRUNG ACROSS SAID MOLD, MEANS FOR SUPPORTING SAID WIRE, SAID SUPPORTING MEANS INCLUDING AN ANCHOR AT EACH END OF SAID WIRE, SAID WIRE HAVING AT EACH OF ITS ENDS AN END PORTION INCLUDING A HEAD AND A DEFORMED SECTION ADJACENT THE HEAD, SAID HEAD PROJECTING LATERALLY BEYOND THE DIAMETER OF THE WIRE, SAID DEFORMED SECTION HAVING FLAT FACES FORMED BY COMPRESSING THE WIRE RADIALLY, EACH OF SAID ANCHORS HAVING A RECESS TO RECEIVE ONE OF SAID END PORTIONS OF THE WIRE, SAID RECESS HAVING SIDE WALLS EXTENDING AXIALLY INWARD FROM AN END OF THE ANCHOR AND A WALL EXTENDING LATERALLY TO SAID SIDE WALLS, SAID LATERALLY EXTENDING WALL PROVIDING AN ABUTMENT SHOULDER, SAID ABUTMENT SHOULDER ENGAGING THE HEAD OF THE END PORTION TO TRANSMIT FORCE FROM SAID ANCHOR TO SAID WIRE TO TENSION THE WIRE, SAID SIDE WALLS OF SAID RECESS SPACED APART A DISTANCE GREATER THAN THE MINIMUM WIDTH OF SAID DEFORMED SECTION BUT NO GREATER THAN ITS MAXIMUM WIDTH, SAID SIDE WALLS ENGAGING THE FLAT FACES ON THE END PORTION UPON ROTATION OF SAID ANCHOR TO TRANSMIT TORQUE TO THE END PORTION.