| 摘要 |
PURPOSE:To increase the stability in relation to a variation in temperature or a leakage of liquid by maintaining a printing wire at a balancing position in a wide-dot printer head of an electrostrictive driving type in which a liquid is used. CONSTITUTION:When the pressure of a liquid 23 for enlarging the displacement, which is located in a cylinder, is raised by a thermal expansion, the liquid 23 pushes a printing wire 22 out or is going to flow out into a reservoir 25 through a slender pipe 24. When the printing wire 22 is restrained with an appropriate strength by a spring 26, however, the liquid 23 flows out to resservior 26. In the same way, when the temperature lowers or the liquid 23 in the cylinder leaks out, the pressure of the liquid 23 in the cylinder falls, and thus the liquid 23 is supplied from the reservoir 25 through the slender pipe 24. The sufficiently- slender pipe 24 and the reservoir 25 absorb only a gentle variation in pressure caused by the thermal expansion, while not abosrbing nearly at all a pulsative variation in pressure caused by printing. Therefore, the adverse effect of the thermal expansion or the leakage of liquid can be prevented without damaging the function of enlarging the displacement. |
