Patent ID: 8006878

Claim:
An apparatus for cracking a connecting rod by integrally forming a connecting rod having a larger end and a smaller end, setting a joint hole in said larger end over a pair of spreaders, pressing a wedge into said pair of spreaders, and spreading said spreaders apart from each other to crack said larger end into a cap part and a rod part, comprising: a workpiece positioning and holding mechanism having a fixed stage fixedly mounted on a base and a movable stage disposed in facing relation to said fixed stage and horizontally movable toward and away from said fixed stage, said workpiece positioning and holding mechanism includes a support surface being arranged to extend beneath said smaller end of the rod part of said connecting rod positioned at a predetermined position with one of said spreaders near said rod part, said rod part being horizontally positioned on the fixed stage and being fixed to said fixed stage and the other spreader near said cap part is fixed to and displaceable in unison with said movable stage for holding said connecting rod thus set; and a loading mechanism for applying a fracture load in a vertical downward direction in which said wedge is pressed in, to crack said larger end; wherein said workpiece positioning and holding mechanism comprises: a first support mechanism, which is displaceable in a horizontal direction, for horizontally pressing shoulders of said larger end of said connecting rod near said cap part toward said smaller end, said first supporting mechanism including a third workpiece support member and a fourth workpiece support member, said third workpiece support member including a first end for abutting against the shoulders of the cap part and a second end operatively positioned adjacent to the fourth workpiece support member; a second support mechanism for pressing downwardly said fourth workpiece support member, said fourth workpiece support member being movable downwardly in a vertical direction for engaging the first end of the said third workpiece support member with the shoulders of the cap part thereby to lock said first support mechanism to prevent said first support mechanism from being displaced in the horizontal direction; and a second workpiece support member having a presser, said second workpiece support member being actuated wherein said presser presses downwardly on an upper surface of said rod part of said connecting rod; said first support mechanism and said second support mechanism being fixed to said movable stage for displacement in unison with said movable stage.