| 摘要 |
PURPOSE:To prevent an erroneous change-over from a use mode in a pulling system to a use mode in a pushing-in system, by a construction wherein a plate rotatably supporting a driving shaft rotated as one body with a driving wheel of a tractor can be locked. CONSTITUTION:On the outside of a side plate 2, a locking plate 28 for locking the plate 7 at an upper position is supported in the state of being energized to the side of a support shaft 8 by a spring 30 so that it can be turned with a pin 29 as a center, and is provided with an upwardly directed stepped part 31 for supporting the driving shaft 9. When this printer for printing on a paper provided with sprocket holes is used in the mode in the pushing-in system, the plate 7 is turned downward, and when the printer is used in the mode in the pulling system, the plate 7 is turned upward. In the condition wherein the plate 7 is located at an upper position, when the plate 7 is erroneously pressed downward, it is prevented from being moved downward, since the stepped part 31 of the locking plate 28 is located beneath the driving shaft 9. |
