摘要 |
The present specification discloses a swaging press including a piston member co-operable with a plurality of die shoes to drive the die shoes inwardly upon axial movement of the piston member during a swaging operation, the piston member having a frusto-conical recessed region divided into a plurality of circumferentially disposed bearing surface zone of a defined axial length, each of the bearing surface zones having an inner axial end with a numerical radius of curvature less than or equal to the radius of curvature of a circular line forming the lateral edges of each of the bearing surface zones at the inner axial end whereby at least 50% of the outer bearing surface of each said die shoe remains in bearing engagement with the adjacent said bearing surface zone over the axial movement of the piston member during a swaging operation. |