PURPOSE: To obtain the optimum contact state by freely fitting a contactor which crosses at right angles with the both edge parts of a connection rod in slidable ways in the vertical direction and installing polishing members supported by a spring member at the both edges of a contactor pin and polishing the inclined inner wall surface of a V-shaped pulley by transferring the holding shaft of the connecting rod in the axial direction, thus preventing the reduction of the friction coefficient.

CONSTITUTION: A connecting rod which is slidable in the direction crossing at right angles with the top edge part of a holding shaft is arranged, and a contactor 14 which is slidable in the vertical direction is freely fitted in the direction crossing at right angles with the connecting rod, and the polishing members 15 and 15' urged by the spring members 22 and 22' installed onto a pin 16A are provided. The holding shaft is shifted in the axial direction, and the spring members 22 and 22' are deflected by attaching the inclined surfaces 19 and 19' of the collars 18 and 18' fixed onto the pin 16A onto the inclined inner wall surface of a V-shaped pulley, and the inclined inner wall surface is polished by compulsorily revolving the polishing members 15 and 15' contacting the inclined inner wall surface. At this time, a revolution speed difference is generated between the polishing members 15 and 15' and the V-shaped pulley, and favorable polishing is carried out. Therefore, the reduction of the friction coefficient with the lapse of operation time is prevented, and the most proper contact state can be obtained.