Patent ID: 7707866

Claim:
A die separator cylinder for use in separating first and second portions of a metal forming die set, said die separator cylinder comprising: a housing comprising a bore and a gas-containment space; a piston that is adapted to reciprocate in said bore between an extended position and a depressed position; a bore outflow path for flow of gas from said bore to said gas-containment space, said bore outflow path comprising at least one check valve operatively located between said bore and said gas-containment space, said check valve allowing flow of gas from said bore to said gas-containment space when said piston moves inward in said bore toward said depressed position and restricting flow of gas from said gas-containment space to said bore when said piston moves outward in said bore from said depressed position toward said extended position; a restricted bore inflow path that fluidically connects said bore and said gas-containment space, wherein said restricted bore inflow path permits flow of gas from said gas-containment space to said bore when gas pressure in said gas-containment space exceeds gas pressure in said bore; wherein said bore outflow path and said bore inflow path define asymmetrical gas flow rates relative to each other so that said when said bore is charged with an inert gas, said inert gas biases said piston to said extended position with a force that varies depending upon an elapsed time interval after said piston moves from said depressed position to said extended position.