PURPOSE: To provide an equipment for warping knitting yarns for a warping machine around a beam, having a specified structure in which the reed unit for warping is reciprocated by utilizing normal and reverse rotational motions of a ball screw, capable of a high-speed operation while keeping the noise to a low level and excellent in high-speed stability.

CONSTITUTION: A rotational motion is initially applied to a ball screw 3 by a normal-reverse rotation clutch 2 and the bracket 5 is operated by rotation of this ball screw 3. When a part of the bracket 5 is then brought into contact with touch sensors 8 and 8' for controlling the double stroke of the bracket 5, the normal-reverse rotation clutch 2 is operated in the opposite direction to that in the above-mentioned operation so as to operate the ball screw 3 and the bracket 5 in turn in the opposite direction The bracket 5 is reciprocated thereby and the reed unit (A) for warping connected to the bracket 5 is reciprocated according to the warping width. The machine in this invention has the above-mentioned system. The width of warping is recommendably adjusted by controlling the distance between a pair of left and right touch sensors 8 and 8'.