Apparatus for securing deformable sheet metal elements

Claim 1

APPARATUS FOR SECURING ONE PORTON OF DUCTILE SHEET METAL TO ANOTHER, COMPRISING A BASE MEMBER HAVING AN ANVIL ASSOCIATED THEREWITH, SAID ANVIL INITIALLY BEING COMPLETELY TELESCOPED WITHIN SAID BASE MEMBER, A PUNCH SLEEVE LOCATED ABOVE THE BASE MEMBER AND HOUSING A PUNCH OF GREATER DIAMETER THAN AND CO-AXIAL WITH THE ANVIL, AND MEANS FOR MOVING SAID BASE MEMBER, ANVIL, PUNCH SLEEVE, AND PUNCH RELATIVE ONE TO THE OTHER IN TIMED RELATION SO AS TO SEQUENTIALLY MOVE THE PUNCH SLEEVE AND ANVIL TOWARD EACH OTHER TO SURROUND AND CLAMP AREAS OF THE SUPERIMPOSED PORTIONS OF SHEET METAL TO BE SECURED, MOVE THE ANVIL TO PRESS THE CLAMPED AREAS INTO THE PUNCH SLEEVE TO EFFECT DEFORMATION OF THE CLAMPED AREAS SUBSTANTIALLY TO A FRUSTRUM OF A CONE THE SLOPING SIDES OF WHICH EXTEND ACROSS A SPACE FORMED BETWEEN THE PUNCH SLEEVE AND THE ANVIL, AND MOVE THE PUNCH TO IMPACT EXTRUDE METAL FROM THE CLOSED END OF THE FRUSTRUM INTO SAID SLOPING SIDES THEREBY TO EFFECT DEFORMATION AND INTERLOCKING OF SAID FRUSTRUM SIDES IN SAID SPACE.