| 摘要 |
PURPOSE:To enable a drive-transmitting medium to be securely maintained with a constantly fixed tension, by a construction wherein a wedge provides the other pulley with a tendency to move outward in the direction of a tension on a drive-transmitting medium. CONSTITUTION:The other pulley 29 is inserted into a gate form turnable frame 30, and is supported by a center shaft 31 penetrating through the pulley 29 and the frame 30. The frame 30 is provided with shaft holes 30a, 30a at lower ends thereof, and is fitted to the left end of a structural member 22 by a fitting shaft 32 penerating through shaft holes 22b, 22b of an extended part 22a and the shaft holes 30a, 30a. The shaft 32 is prevented from slipping off by an E-ring 33, and the frame 30 can be turned with the shaft 32 as a center. On both sides of the pulley 29 and the frame 30, wedges 34, 34 are placed between the shaft 31 and a left frame side plate 20, and compression springs 35, 35 are placed between the wedges 34, 34 and bent bottom part 20b of the side plate 20 to energize the wedges 34, 34 in the direction for entering between the center shaft 31 and the side plate 20. |
