Supporting structure of an armature of a wire dot printer head

#1. Field of the Invention

#The present invention relates to a wire dot printer head of wire dot printer, and more particularly, to a structure where magnetic resistance between an armature and a yoke is reduced.

#2. Discussion of the Background

#A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

#FIG. 1 is a central longitudinal cross-sectional front view of a wire dot printer head of the present invention;

#FIG. 2 is a partial longitudinal cross-sectional side view along a line A—A in FIG. 1 for explanation of armature support structure;

#Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

#An embodiment of the present invention will be described with reference to FIGS. 1 to 3.

#First, the entire structure of a wire dot printer head 1 will be described with reference to FIG. 1. The wire dot printer head 1 is formed by sequentially depositing a front case 2, a circuit board 3, a yoke 4, an armature spacer 5 and a rear case 6. The front case 2 and the rear case 6 are connected to each other by attachment screws (not shown), and the circuit board 3, the yoke 4 and the armature spacer 5 are held between the front case 2 and the rear case 6. The yoke 4 is made of magnetic material. The yoke 4 has an outer peripheral part 8 and an inner cylindrical part 9, and plural cores 10 are integrally formed between the outer peripheral part 8 and the cylindrical part 9. These cores 10 have a magnetic pole surface 11 at an end in an axial direction. A coil 12 is attached around an outer periphery of the cores 10. Plural cavities 13 corresponding to the cores 10 are formed in the outer peripheral part 8 of the yoke 4. An armature 14 opposed to the core 10 is comprised of an arm 16 to which a wire 15 is wax-bonded and a magnetic circuit formation member 17 welded to both side surfaces of the arm. These armatures 14 are rotatably supported by a support shaft 18 as a support point. The direction of the support shaft 18 is orthogonal to an axis of the core 10. A wire guide 7 is provided with plural guide chips 19 to slidably guide the wire 15, and an end guide 20 which arrays the ends of the wires to slidably guide the arrayed wires 15 is provided at an end of the front case 2.