Clam shell die cutter

An improvement in a die cutting press for cutting sheet material comprising:

• a keyless die means for cutting said sheet material, said die means having opposing sides with lineal extent;
• first means for providing support for said keyless die means;
• second means adapted for pressing said sheet material against said keyless die means, said sheet material being cut by said keyless die means;
• clamping means for temporarily fixing said keyless die means supported by said first means, said clamping means being operable to selectively and quickly release and clamp said keyless die means to allow removal, manipulation and insertion of said keyless die means onto said first means, wherein said clamping means is comprised of a first and second clamping bar extending across the entire opposing sides of said keyless die means, and motive means for simultaneously displacing said first and second bars in opposing directions to selectively bring said first and second bar together or to draw said first and second bar apart, wherein said first and second bar comprise generally straight cross bars, said first and second cross bars being displaced by said motive means across said first means, and wherein said motive means comprises first and second parallel drive screws, said first and second parallel drive screws being threaded to opposing first and second ends of said first and second cross bars, each of said parallel drive screws having two threaded portions, said threaded portions of each parallel drive screw having an opposite screw direction so that rotation of said parallel drive screws simultaneously displace said cross bars in opposing directions to repeatably and accurately position said keyless die means within said press,
• whereby said keyless die means may be readily manipulated to perfect cutting of said sheet material by said keyless die means.

An improvement in a clam shell press having a stationary frame for supporting a keyless die member having a lineal extent along opposing sides, said keyless die member being supported at a defined position and a movable bridge for pressing sheet material against said die member causing said die member to cut into said sheet material, the improvement comprising:

• clamping means for selectively and securely but temporarily accurately fixing said keyless die member at a defined position within said press, wherein said clamping means comprises a first and second opposing bar;
• and
• motive means for selectively operating said clamping means to clamp said keyless die member at said defined position or to release said keyless die member from said press, wherein said motive means is operative to drive said first and second opposing bars simultaneously in opposite directions with respect to each other, wherein said first and second bars are fixed to said frame and wherein said motive means comprises:
• first and second opposing and parallel drive screws, said first and second parallel drive screws threadably coupled to opposing ends of both said first and second bars, said first and second parallel drive screws being simultaneously driven to move said first and second bars in opposing directions on said frame to clamp or release said keyless die member;
• and
• means coupling said first and second parallel drive screws for transferring rotary motion from said first parallel drive screw to said second parallel drive screw to simultaneously and synchronously rotate said first and second parallel drive screws,
• whereby said keyless die member may be repeatedly fixed and removed from said press for adjustment, refixed, tested and readjusted until a satisfactory cut of said sheet is obtained.