Punching and extrusion die

Claim 2

Hole forming apparatus for punching and forming a reinforced opening of substantially bell-shaped configuration in a substantially flat metal sheet comprising: a punch having a cutting portion at its leading end for cutting and punching a hole in a metal sheet, and a forming portion following said cutting portion; said cutting portion comprising a cutter extending from the leading end of said punch, and said forming portion including a flared section providing a material deforming shoulder, a cylindrical section having a greater lateral dimension than said cutter, and an outwardly radiused section; and a die having a channel formed therein for receiving a portion of said punch and a surface surrounding said channel, said punch and die being cooperable upon axial movement of said punch into the channel of said die to sequentially cut a hole in a flat metal sheet located between the die and the punch and then shape and force the material surrounding the hole against the surface of the die to form a substantially bell-shaped opening having a substantially flat bottom surface spaced from the plane of the sheet material.

Claim 3

Apparatus as claimed in claim 1 wherein said flared section defines an inverted truncated conical section.

Claim 4

Apparatus as claimed in claim 1 wherein said die includes an upper surface, a cylindrical recess therein for receiving at least a portion of the material surrounding the holes during a hole forming operation, and a channel in communication with said recess for receiving the material cut from the metal sheet.

Claim 5

Apparatus as claimed in claim 3 wherein said recess includes an arcuate shoulder defining the outer periphery thereof.

Claim 6

Apparatus as claimed in claim 3 wherein said channel includes a pilot portion in axial alignment with said punch for guiding at least a portion of said forming portion through said die.

Claim 7

Apparatus as claimed in claim 3 wherein said die includes an annular flange for mounting said die on a support.

Claim 8

Hole forming apparatus for punching and forming a reinforced opening of substantially bell-shaped configuration in a substantially flat metal sheet comprising: a punch having a cutting portion at its leading end and a forming portion following said cutting portion; a die having an upper surface, a cylindrical recess formed in said upper surface, said cylindrical recess including an arcuate shoulder defining the outer periphery thereof; and a channel in communication with said recess, said channel including a pilot portion for axially receiving a portion of said punch, said punch and die being cooperable upon axial movement of said punch into the pilot portion of said die to sequentially cut a hole in the flat metal sheet placed between the punch and die and then force and shape the material surrounding the hole against said arcuate shoulder and the surface of said cylindrical recess to form a substantially bell-shaped opening in the metal sheet having a substantially flat bottom surface spaced from the plane of the sheet material, said forming portion including a flared section providing a material deforming shoulder, an outwardly radiused section, and a cylindrical section intermediate said flared section and said radiused section.

Claim 9

Hole forming apparatus for punching and forming a reinforced opening of substantially bell-shaped configuration in a substantially flat metal sheet comprising: a punch having a cutting portion at its leading end and a forming portion following said cutting portion; a die having an upper surface, a cylindrical recess formed in said upper surface, said cylindrical recess including an arcuate shoulder defining the outer periphery thereof; and a channel in communication with said recess, said channel including a pilot portion for axially receiving a portion of said punch, said punch and die being cooperable upon axial movement of said punch into the pilot portion of said die to sequentially cut a hole in the flat metal sheet placed between the punch and die and then force and shape the material surrounding the hole against said arcuate shoulder and the surface of said cylindrical recess to form a substantially bell-shaped opening in the metal sheet having a substantially flat bottom surface spaced from the plane of the sheet material, said forming portion including a flared section providing a material deforming shoulder, an outwardly radiused section, and a cylindrical section intermediate said flared section and said radiused section.

Claim 10

Hole forming apparatus for punching and forming a reinforced opening of substantially bell-shaped configuration in a substantially flat metal sheet comprising: a punch having a cutting portion at its leading end and a forming portion following said cutting portion; said cutting portion including a cutter extending from the leading end of said punch, and said forming portion including a flared section providing a material deforming shoulder, a cylindrical section having a greater lateral dimension than said cutter, and an outwardly radiused section; a die, said die having an upper surface, a cylindrical recess formed in said upper surface, an arcuate shoulder defining the outer periphery of said cylindrical recess, an axial bore in said die communicating with said recess, said bore including a pilot portion of reduced diameter adjacent to said recess; said punch and die being cooperable upon movemenT of the leading end of said punch into the pilot portion of said bore to sequentially cut a hole in a metal sheet disposed between the punch and the die and then displace the edge of the hole onto the surface of said cylindrical recess by shaping the material surrounding said hole around said arcuate shoulder and forcing the material onto the surface of said recess to define a substantially bell-shaped opening in the metal sheet having a substantially flat bottom surface spaced from the plane of the sheet material.

Claim 11

Hole forming apparatus for punching and forming a reinforced opening of substantially bell-shaped configuration in a substantially flat metal sheet comprising: a punch having a cutting portion at its leading end and a forming portion following said cutting portion; said cutting portion including a cutter extending from the leading end of said punch, and said forming portion including a flared section providing a material deforming shoulder, a cylindrical section having a greater lateral dimension than said cutter, and an outwardly radiused section; a die, said die having an upper surface, a cylindrical recess formed in said upper surface, an arcuate shoulder defining the outer periphery of said cylindrical recess, an axial bore in said die communicating with said recess, said bore including a pilot portion of reduced diameter adjacent to said recess; said punch and die being cooperable upon movemenT of the leading end of said punch into the pilot portion of said bore to sequentially cut a hole in a metal sheet disposed between the punch and the die and then displace the edge of the hole onto the surface of said cylindrical recess by shaping the material surrounding said hole around said arcuate shoulder and forcing the material onto the surface of said recess to define a substantially bell-shaped opening in the metal sheet having a substantially flat bottom surface spaced from the plane of the sheet material.

Claim 12

Apparatus as claimed in claim 7 wherein said cutting portion comprises a cutter extending from the leading end of said punch.