| 摘要 |
PROBLEM TO BE SOLVED: To produce a lightweight coil structure to make an antenna, etc., light in weight and hardly damage. SOLUTION: A coil 14 which is made by helically winding a metal wire with equal distance in equal outer diameter is unified with a hollow cap 12 made of an insulating material such as the synthetic resin, etc., on its inner surface and with almost half outer section of the coil 14 buried in the cap 12. Thus, a coil element (coil structure) 10 is obtained. The element 10 has a cavity 16 and accordingly is light in weight. Then the element 10 is pressed into a recess groove 20 of a metallic element stage 18 from its upper part, and an upper part 22 of the outer circumference of the stage 18 is caulked toward its center from the outside. Thus, the lower edge of the coil 14 is pressed to the inner circumference 24 of the groove 20 and connected electrically to the stage 18. As a result, the coil 14 is used as a helical antenna. |
