| 摘要 |
PURPOSE:To contrive a higher printing speed, by providing a rear frame which is formed of an elastic material in a cylindrical form with an end closed and is disposed on a side surface of the second yoke so as to restrict the normal position of a plunger, and a mass body disposed between and end part of the plunger and a bottom part of the rear frame. CONSTITUTION:A rear frame 19 is formed of an elastic material such as a lowly resilient rubber in such a shape that a rectangular flange part 19b is extended from the edge of an opening on one side of a cylindrical part 19a, and is provided with a fitting hole 19c into which a projection 17c of the second yoke 17 is to be fitted. After engaging the fitting hole 19c with the projection 17c, the frame 19 is fixed to the outer surface of the second yoke 17 by caulking or the like. A mass body is formed of a metallic material in a disk form provided with a through-hole 20a communicated to a vent hole 19e, and is disposed at a bottom part 19d of the frame 19 opposed to an end part of a plunger 12. The weight of the mass body 20 is set to be approximately equal to or greater than the weight of the plunger 12. By the synergistic effect of the eight of the mass body and a shock-absorbing action of the frame 19, the energy of the plunger 12 at the time of are turning action thereof is absorbed, so that the secondary bound of the plunger 12 can be greatly reduced. |
