| 摘要 |
PURPOSE:To increase the strength of a brazed portion to enhance the durability, by a method wherein the rear end surface of a needle is supported by a receive surface. CONSTITUTION:At the tip of an armature 3, a stage portion 15 having L-shaped cross section is formed which consists of a support surface 13 disposed at right angles to the board thickness direction of the armature 3 and a receive surface 14 vertically disposed to the support surface 13. A needle 11 is bonded to the support surface 13 at one side thereof as well as to the receive surface 14 at the rear end surface thereof, thus being brazed on the armature 3. The armature 3 is so designed as to be identical to the outer diameter of the needle 11 in width at the tip end thereof and as to have a relatively thin board thickness which is a little larger than the outer diameter of the needle 11 in size. The area of the receive surface 14 is substantially identical to that of the rear end surface of the needle 11. In the constitution as mentioned above, excitation of a coil 2 leads the armature 3 to rotate around the fulcrum of a contact portion 16 thereon abutting to a yoke 1 to drive the needle 11 in the printing direction. At this time, contactness of the needle 11 with the receive surface 14 at the rear end surface thereof prevents the brazed portion from being subjected to shear force. |
