Patent ID: 8225686

Claim:
A chips dischargeable wiper disposed between a nut and a ball screw, the ball screw being formed with a helical groove for cooperating with the nut, an outer periphery of the chips dischargeable wiper being fixed to the nut, a flange extending along a complementary helical path to match the helical groove and being formed on an inner surface of the chips dischargeable wiper and shaped to fit in the helical groove of the ball screw, and an interval being formed between the flange and the helical groove, the chips dischargeable wiper being characterized in that: on the flange is integrally formed at least one rib which is an elongated block running along a width of the flange, the rib has two lateral surfaces, one of the two lateral surfaces is slanted toward the center from both ends thereof to form a concave portion in the center thereof, so that foreign objects and dusts wiped by the rib along the helical groove are pushed from both ends of the rib to the center of the concave portion, and a thickness of the rib is designed to match the interval between the flange and the helical groove, wherein the thickness of the rib is measured from a top surface of the flange to a bottom of the helical groove.