| 摘要 |
PURPOSE:To suppress the secondary bound of a plunger and enable the plunger to be operated favorably and at high speed, by providing a mass body which is formed from a metallic material in a cylindrical form provided with an axial through-hole and having a weight not smaller than that of the plunger and has an outer peripheral part fixed to the inner peripheral part of a shock-absorbing member so that an end part thereof is opposed to an end part of the plunger. CONSTITUTION:A shock-absorbing member 20 is formed from a shock-absorbing material in a cylindrical form, and has an outer peripheral part fixed to an inner peripheral part of a rear frame 19. A mass body 21 is formed from a metallic material in a cylindrical form provided with an axial through-hole 21a and having a weight not smaller than that of a plunger 12, and has an outer peripheral part fixed to an inner peripheral part of the shock-absorbing member 20 so that an end part thereof is opposed to an end part of the plunger 12. The mass body 21 restricts the normal position of the plunger 12, and through its synergistic effect with the shock-absorbing member 21, absorbs the energy of the plunger 12 at the time of a returning action of the latter, thereby markedly reducing the secondary bond of the plunger 12. Accordingly, a higher printing speed can be contrived. |
