| 摘要 |
<p>PROBLEM TO BE SOLVED: To restrain generation of wearing flaw on the outer peripheral surface of a cable which is caused by idling of a drawing ball when the cable is locked by some causes, by setting Shore hardness of rubber material constituting the drawing ball in a specified range. SOLUTION: In a system, four ball drawing frames 5 are arranged at four corners of a square, and a cable 1 which is constituted in an endless shape by linking both ends to drawing balls 5a of the ball drawing frame 5 is suspended. The degree of wear of the respective balls 5a is measured by using the system and determined as the index of degree of wear of the cable 1. Shore hardness of rubber material constituting the drawing ball 5 is set in the range of 45-55 by the index. As a result, damage of a cable sheath can be restrained in the case that the cable 1 is locked by some causes when the cable 1 is drawn, and the life of the drawing ball 5a can be prolonged.</p> |
