PURPOSE: To check an insulation board from moving between a field core and a fixed terminal certainly by furnishing a bobbin with a projection, which is made to intrude into a hole in the insulation board against the resistance given from the hole.
CONSTITUTION: A bobbin 8 is constructed in such an arrangement that a tapered part 30 and pressure fitting part 31 of a projection 26 protrude from a hole 28 provided in a field core 16. A hole 29 in an insulation board 25 is positioned in alignment with the tip of this projection 26, which is intruded against a resistance given from this hole 29. Then the projection 26 deforms to squeeze the diameter, and a groove 27 is closed, and the other end of an attraction coil 9 placed in this groove 27 is pinched within it and retained. In the condition that the projection 26 is arranged in the hole 29, the projection 26 presses the hole 29 to the outside with the restrative force of the projection 26, and the insulation board 25 is fixed to the projection 26. As a result, the insulation board 25 is fixed to the bobbin 8 through the field core 16. Accordingly the insulation board 25 is certainly checked from moving between the field core 16 and fixed terminals 20, 21.
SAKANO HIDEO
YAMANOUCHI SHINYA
