US 4,241,625 AGranted

Method of making a wire drawing die

AssigneeFort Wayne Wire Die, Inc.

InventorsLawrence W. Corbin, Charles Carson

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Abstract

A metal casing is provided having flat, parallel front and back sides. A first cylindrical cavity having a bottom wall is formed in the front casing side. A cylindrical metal plug having top and bottom ends is secured by heat shrinking in the first casing cavity, the bottom end having a second, concentric cylindrical cavity formed therein and engaging the bottom wall of the cavity. A cylindrical metal blank having opposite ends and a concentric core formed of a synthetic hard, wear-resistant material, such as polycrystalline aggregate of synthetic or natural diamond or polycrystalline cubic boron nitride, is secured in the second cavity by heat shrinking with one end engaging the bottom thereof and the other end engaging the first casing cavity bottom wall. The top end of the plug and the back side of the casing have concentric countersunk openings therein respectively extending therethrough to the core, and the core has a concentric die opening formed therethrough communicating between the countersunk openings.

Claims8

Dependent claims

The method of making a wire drawing die comprising the steps of:

providing a metal casing having front and back sides;
forming a first cavity in said front casing side having a flat bottom wall and a cylindrical side wall extending from said front casing side to said bottom wall;
providing a metal plug having flat top and bottom ends and a cylindrical outer surface extending between said ends;
forming a second cavity in one of said first cavity bottom wall and said plug bottom end, said second cavity having a cylindrical side wall extending to a flat bottom;
forming countersunk openings in said top end of said plug and said back side of said casing respectively concentric with said cavities and extending to said bottom of said second cavity and the other of said first cavity bottom wall and said plug bottom end;
providing a metal blank having flat opposite ends and a cylindrical outer surface extending between said ends, said blank having a concentric core formed of hard, wear-resistant material;
securing said blank in said second cavity by heat-shrinking to provide an interference fit therewith and with one end of said blank engaging the bottom of said second cavity;
securing said plug in said first cavity by heat-shrinking to provide an interference fit therewith and with the other end of said blank engaging the other of said first cavity bottom wall and plug bottom end;
carrying out both said heat-shrinking steps employing a temperature of about 600.degree. F. to 1,000.degree. F. and a force of about 1,200 to about 2,400 pounds;
and drilling a die opening in said core communicating between said countersunk openings and concentric therewith.

7 more elements

The method of making a wire drawing die comprising the steps of:

providing a metal casing having front and back sides;
forming a first cavity in said front casing side having a flat bottom wall and a cylindrical side wall extending from said front casing side to said bottom wall;
providing a metal plug having flat top and bottom ends and a cylindrical outer surface extending between said ends;
forming a second cavity in one of said first cavity bottom wall and said plug bottom end, said second cavity having a cylindrical side wall extending to a flat bottom;
forming countersunk openings in said top end of said plug and said back side of said casing respectively concentric with said cavities and extending to said bottom of said second cavity and the other of said first cavity bottom wall and said plug bottom end;
providing a metal blank having flat opposite ends and a cylindrical outer surface extending between said ends, said blank having a concentric core formed of hard, wear-resistant material;
securing said blank in said second cavity by heat-shrinking to provide an interference fit therewith and with one end of said blank engaging the bottom of said second cavity;
securing said plug in said first cavity by heat-shrinking to provide an interference fit therewith with the bottom end of said plug engaging said first cavity bottom wall and with the other end of said blank engaging the other of said first cavity bottom wall and plug bottom end;
and drilling a die opening in said core communicating between said countersunk openings and concentric therewith.

6 more elements

Dependencies are inferred from the claim text.