| 摘要 |
In a bar puller, pins mount serrated rollers to pivoting arms, which are mounted by additional pins to a bar puller body. The body houses movable cups positioned to compress springs in response to pivoting motion of the pivoting arms. A cover retains the springs and cups in the body. In a manufacturing process where elongated stock material needs to be positioned automatically, such as in a CNC turning center, the bar puller manipulates the elongated material in the machine by holding it rigidly so that the bar puller can move the elongated material on the axis of elongation. This is accomplished by forcing the end effectors over the material, which separates the end effectors by pivoting the arms. The geometry of the pivoting arms causes interaction with the cups and springs to generate an opposing spring force to separate the end effectors. |
| 主权项 |
1. A relocating tool for use when mounted on an automated machine that controls movement of the relocating tool to engage, reposition, and disengage a workpiece, wherein the relocating tool comprises:
a body that defines at least two parallel spring chambers, each spring chamber having a bottom opening and containing a spring, and a slidable piston is located in each spring chamber, below the spring in a position where the piston can be contacted near the bottom opening to raise the piston and correspondingly to compress the spring; at least a pair of pivot arms that is attached to the body near their top ends by an arm pin that secures each pivot arm to the body and allows the opposite, bottom ends of the pivot arms to pivot between a position of relative minimum separation and a position of relative maximum separation; wherein: each pivot arm of the pair has an inside facing side wall surface that in the position of minimum separation is laterally nearest to the other pivot arm of the pair; each pivot arm of the pair also has an outside facing side wall that when in the position of minimum separation is laterally opposite from the other pivot arm; each pivot arm is attached to the body at a location where the respective pivot arm is associated by proximity with a different one of the spring chambers; said arm pin maintains the top end of each pivot arm in juxtaposition to the bottom opening of the associated spring chamber, in a location where swinging the bottom ends of the pivot arms toward the position of maximum separation causes an outside end portion of the respective top ends to raise the pistons in the associated spring chambers and compress the contained springs; the outside end portion of the top end of each pivot arm defines a cam that has a profile that is eccentric with respect to the arm pin of the pivot arm; the eccentric cam profile controls how far the associated spring is compressed as each pivot arm progressively increases its angle of pivot toward the outside; and the eccentric cam profile is such that with increasing pivot angle of a pivot arm, the cam compresses the associated spring along a displacement curve that increases at a decreasing rate. |
