| 摘要 |
<p>PURPOSE:To run even a tape having high coefficient of friction and small strength stable while preventing damaging, by shifting the spring fitting position of a tension adding part by cassette inserting force, and thus shortening the expansion length of a spring. CONSTITUTION:A cassette 18 is inserted as shown by an arrow H, a rotary metallic fixture 23 rotates as shown by an arrow I, and a rotary arm 16 and the rotary metallic fixture 23 are released. In this state, if a boat moves as shown by an arrow F, a tension arm 6 is rotated counterclockwise by a spring 5 and a push rod 21 is pushed up by a spring 14 and fixed by a stopper 24. An arm 6 is drawn by the spring 5 in the direction as shown by an arrow K to rotate in the direction as shown by an arrow J, reducing the tensile strength of the spring 5. When the boat 20 moves in the direction as shown by an arrow E, the arm 6 is rotated as shown in the direction by an arrow G by the moving force of the boat 20 and the push rod 21 is pressed by a push plate 13 in the direction as shown by an arrow M. The arm 16 moved by the push rod 21 rotates in the opposite direction to the arrow J to return to its intial state.</p> |
