Apparatus for automatically applying equalized pressure to a rotary cutting die

In a press assembly comprising a frame;

• a rotary anvil connected to the frame and including a first end and a second end;
• a rotary cutting die disposed above the rotary anvil, connected to the frame, and including a first end adjacent to the first end of the rotary anvil and a second end adjacent to the second end of the rotary anvil;
• a pressure bar disposed above the rotary cutting die and including a first end proximate to and for interacting with the first end of the rotary cutting die, and a second end proximate to and for interacting with the second end of the rotary cutting die;
• a bridge bar disposed above the pressure bar and connected to the frame;
• and a pair of jackscrews movably connected to the bridge bar, wherein the press assembly is so constructed and arranged that upon proper operation, respectively, of a first jackscrew and a second jackscrew of the pair of jackscrews, the first jackscrew functions to apply a force to the pressure bar proximate to the first end of the pressure bar and the second jackscrew functions to apply a force to the pressure bar proximate to the second end of the pressure bar;
• and wherein the pressure bar translates the forces applied thereto to the rotary cutting die in the form of a first force applied proximate to the first end of the rotary cutting die and a second force applied proximate to the second end of the rotary cutting die so that pressure is applied between the rotary cutting die and the rotary anvil, wherein an improvement thereto comprises:
• a first hydraulic actuator constructed and arranged to interact with the first jackscrew to develop a first hydraulic pressure that corresponds to the first force,
• wherein said first hydraulic actuator includes a first cylinder connected to the bridge bar and a first piston movably connected to said first cylinder,
• wherein said first hydraulic actuator is so constructed and arranged to, in response to increases in the force applied by the first jackscrew, cause said first piston to move relative to said first cylinder such that said first hydraulic pressure increases,
• wherein said first hydraulic actuator is so constructed and arranged to, in response to decreases in the force applied by the first jackscrew, allow said first piston to move relative to said first cylinder so that said first hydraulic pressure decreases, and
• wherein said first piston defines a first bore therethrough and the first jackscrew extends through said first bore and threadedly engages said first piston in a manner that facilitates movement of the first jackscrew relative to said first piston,
• a second hydraulic actuator constructed and arranged to interact with the second jackscrew to develop a second hydraulic pressure that corresponds to the second force,
• wherein said second hydraulic actuator includes a second cylinder connected to the bridge bar and a second piston movably connected to said second cylinder,
• wherein said second hydraulic actuator is so constructed and arranged to, in response to increases in the force applied by the second jackscrew, cause said second piston to move relative to said second cylinder such that said second hydraulic pressure increases,
• wherein said second hydraulic actuator is so constructed and arranged to, in response to decreases in the force applied by the second jackscrew, allow said second piston to move relative to said second cylinder such that said second hydraulic pressure decreases, and
• wherein said second piston defines a second bore therethrough and the second jackscrew extends through said second bore and threadedly engages said second piston in a manner that facilitates movement of the second jackscrew relative to said second piston,
• wherein said first hydraulic actuator and said second hydraulic actuator are in fluid communication so that said first hydraulic pressure and said second hydraulic pressure are equalized, whereby said first hydraulic pressure equals said second hydraulic pressure to define a system hydraulic pressure, and
• wherein said first hydraulic actuator and said second hydraulic actuator are so constructed and arranged that when said first hydraulic pressure equals said second hydraulic pressure, the first force equals the second force,
• whereby the first force and the second force are automatically equalized, whereby the pressure between the rotary cutting die and the rotary anvil proximate to the first ends thereof is substantially similar to the pressure between the rotary cutting die and the rotary anvil proximate to the second ends thereof, whereby the pressure distribution between the rotary cutting die and the rotary anvil is substantially uniform.