| 摘要 |
Apparatus for positioning a workpiece, such as a piston ring, which has an out-of-round inner circumferential face with a radially inwardly directed portion that deviates from the out-of-round contour. The apparatus includes first and second spaced cylindrical rollers each having a diameter which is substantially less than the diameter of the workpiece. Means are provided for rotating the rollers in the same direction about their respective longitudinal axes. Braking means, which is interposed between the rollers and may be in the form of a brake shoe, has a frontal face positioned with respect to the peripheral surfaces of the rollers so that the frontal face contacts only the portion of the inner circumferential face of the workpiece which deviates from the out-of-round contour. When the frontal face of the braking means or brake shoe is in contact with the deviated portion of the workpiece, the rollers are spaced from the workpiece causing the workpiece to be braked and positioned at the portion of the circumferential face which differs from the normal out-of-round contour. At all other positions of the workpiece, it rests on the rollers with only its own weight and is not touched by the brake shoe. |
