| 摘要 |
PURPOSE:Not to generate a shape variation, a characteristic deterioration etc. in an endless belt-like recording body, by straining the recording body at the time of a regular operation, and releasing the tension of the recording body by use of a tension releasing means in case of non-operation for many hours. CONSTITUTION:A recording body 22 can take either one of state of a strained state or a strain released state by operating a knob 28 of a releasing arm 31. That is to say, at the time of a regular operation, a roll 23 is energized in the direction as indicated with an arrow B by a compression spring 25 through its shaft part 15, therefore, tension is given to the endless belt-like recording body 22. When the knob 28 is moved in the direction as indicated with an arrow B' along a guide groove 27 from said state, the roll 23 also moves in the same direction, tension of the recording body is released, and also when the knob is set into a branch groove extending downwards, in the guide groove 27, the releasing arm 31 is obstructed as to its return in this groove, and the recording body 22 is held in a strain released state. |
