| 摘要 |
PURPOSE:To make the lateral feed of a printing mechanism part constant by automatically correcting the change in the tension of a belt generated by the change in temp., by supporting a follower pulley, over which a belt is trained, by an adjustment base constituted of a material having predetermined coefficient of expansion. CONSTITUTION:A printing mechanism part 6 moves on guide shafts 3, 4 and a printing head 5 is mounted to the upper part thereof. The belt 7 for moving the above mentioned mechanism part 6 is trained over a drive pulley 10 and a follower pulley 11. A taper block 13 is attached to the base part of the pulley holder 12 for supporting the follower pulley 11 by a nut 14. An adjustment base 15 has a taper hole matching with a taper block 13 at the center thereof and is constituted of a material having predetermined coefficient of expansion while the outer shape thereof is set to a taper shape following a side frame hole 1a. Therefore, the increase in the tension of the belt 7 by the rising in circumferential temp. is corrected by the movement of the pulley holder 12 on the basis of the difference between coefficients of expansion of the adjustment base 15 and the taper block 13. At the time of the falling in temp., the pulley holder 12 reversely moved to perform correction. |
