| 摘要 |
PURPOSE:To attempt not only to increase the speed of a release type printing head but also to prolong the stroke thereof, by inclining the opposing surfaces of a bypass magnetic path member and the armature engaged with the notch of said magnetic path member so as to make the same narrower toward an iron core side with respect to the operating direction of the armature. CONSTITUTION:An armature 11 is supported by the leading end part of a cantilevered leaf spring 13 and engaged with the notch 16 formed on the inner periphery side of a perforated disc shaped bypass magnetic path member 12 so as to extend to the radius direction. The opposing surfaces 14, 15 of the bypass magnetic path member 12 and the armature 11 engaged with the notch 16 thereof are inclined so as to become narrower toward the side of an iron core 1 with respect to the operating direction of the armature 11. Therefore, the attraction force P acting between the bypass magnetic path member 12 and the armature 11 by the magnetic flux formed by a permanent magnet through the opposing surfaces 14, 15 has component force Q in an up-and-down direction. As a result, the attraction force of the armature 11 increases by said component force, and the increase in the speed and the prolongation of the stroke of a printing head are enabled. |
