| 摘要 |
PURPOSE:To always perform sharp printing regardless of the temp. of a coil, by mounting a leaf spring type return spring made of a bimetal to a printing head. CONSTITUTION:When the temp. of a printing head is raised by repeating printing operation, a return spring 7 made of a bimetal deformed by bimetal action so that the leaf spring part 7b of the return spring 7 moves in the direction shown by an arrow A at the leading end thereof. Therefore, the pressing force to an armature 1 is reduced. When a current is supplied to a coil 6 in this state, attraction force is generated in a yoke 5 but becomes smaller than that at low temp. because of the high resistance value of the coil 6. However, since the force of the return spring 7 to the armature is small, the armature 1 rapidly starts motion in the same way at the time of low temp. to make it possible to perform printing operation. |
