Punch assembly with feed gap maximization

A punch assembly for forming a workpiece comprising, a punch assembly, said punch assembly including a vertical sleeve with a central bore, a tool holder mounted for axial movement therethrough, a ring-shaped circumferentially extending supporting flange encircling the punch assembly and slidably mounted thereon such that the punch assembly is slideable axially within the flange, the flange being spaced apart from a lower end of the punch assembly and is devoid of a guide bushing around the tool holder, at least one retractor spring is connected between the sleeve and the flange for yieldably biasing the flange downwardly on the punch assembly, a retainer connected to the flange for holding the flange in place on the sleeve and the flange being removable from the sleeve, said tool holder extending downwardly during use toward the workpiece from the flange and an extension control for changing the distance that the tool holder extends below the supporting flange, such that a form height or depth of the workpiece can be established while maximizing a gap between the tool holder and the workpiece, and the tool holder is connected to a part of the punch assembly by a screw-threaded connection for changing the extension thereof below the flange.

For use in a punch press having a punch assembly therein for forming a depression or projection in a workpiece, the improvement comprising, a punch assembly including a vertical sleeve with a central bore, a tool holder mounted for axial movement therethrough, a ring-shaped circumferentially extending supporting flange encircling the punch assembly and slidably mounted thereon such that the punch assembly is slideable axially within the flange, the flange being spaced apart from a lower end of the punch assembly and the flange is devoid of a guide bushing around the tool holder, at least one retractor spring is connected between a portion of the sleeve and the flange for yieldably biasing the flange downwardly on the punch assembly, a member on the assembly for holding the flange in place on the sleeve, the flange being removable from the sleeve, said retractor spring urging the flange downward relative to the punch assembly so as to retract the punch assembly from an extended operating position that is taken to form the workpiece when the punch assembly is struck by a ram mounted on the punch press above the punch assembly.

The combination of a punch press and a punch assembly adapted to be mounted thereon comprising,

• a punch press having an upwardly extending downwardly yieldable punch assembly holder that includes at least one lifter spring as a part of the punch press for elevating a punch assembly supported thereby, said punch assembly including a vertical sleeve with a central bore, a tool holder mounted for axial movement therethrough, a circumferentially extending flange encircling the punch assembly and being slidably mounted thereon as a separate ring such that the punch assembly is slideable axially within the flange, at least one retractor spring is connected between the sleeve and the flange for yieldably biasing the flange downwardly on the punch assembly, and a retainer for holding the flange in place on the sleeve such that the punch assembly is yieldably biased upwardly by both the lifter spring of the punch press and the retractor spring of the punch assembly for maximizing a gap between the tool holder and a workpiece.