PURPOSE: To accurately feed a stock by providing stationary grippers attached to a frame, movable grippers linearly moving between a grip position and a release position, and a cam driving means that opens/closes the movable grippers synchronously with the cycle motion.

CONSTITUTION: This apparatus is equipped with a first cam driving body, which moves movable grippers 22 between a grip position and a release position, and a second cam driving body which releases the movable grippers 22 while they are moving from the release position to the grip position. In addition, the apparatus is provided with a third cam driving body which controls in the manner that stationary grippers are released while the movable grippers are moving from the grip position to the release position. These cam driving bodies are so timed as to fully control the position of the stock, with at least one of the grippers closing over the entire time of total cycle and gripping the stock. The two grippers 21, 22 are in contact with the stock over a sufficient length, preventing slippage, so that the quantity of the stock to be fed coincides accurately with the travelling distance of the movable grippers. As a result, workpieces can be accurately controlled without a stock gage.