| 摘要 |
PROBLEM TO BE SOLVED: To reduce the trouble necessary to regulate the tension of a belt, by eliminating the necessity to regulate the positions of tension rollers separately. SOLUTION: To an interlocking mechanism 73 to interlock tension rollers 71 and 72, a disk form of rotary plate 75 is included. The rotary plate 75 is made rotatable around a bolt shaft 76 provided on the straight line combining a rotary axial line C1 and a rotary axial line C2 in the plane view, within a plane along a base plate 52. The tension rollers 71 and 72 are provided symmetrically as to the bolt shaft 76 on the upper surface of the rotary plate 75, and they are made contactable to a belt 65 at both sides of a driven roller 64 respectively, regardless of the rotating position of the rotary plate 75. When the rotary plate 75 is rotated, the two tension rollers 71 and 72 move at the same moving amount in the directions crossing to the belt 65, and the passage length of the belt 65 between a fixed roller 62 and the driven roller 64 is extended. |
