Matsushita Electric Industrial Co., Ltd.

Kazuji Ota

Susumu Inatsugu

Yoshinobu Nakagawa

Yoshiharu Abe

Koji Sako

Masaaki Yamabayashi

Yusuke Ishito

Naoyuki Yayama

Preparations of piece parts used in coupling a joint and a feeding fixture together and the assembly work involved are made easy and a less expensive antenna can be realized. The antenna disclosed here includes a case of a wireless device, a holder mounted on the case, a first antenna element accommodated in the holder so as to be freely movable by sliding, a stopper coupled with one end of the first antenna element and connected electrically to the holder by sliding, a cylindrical column like joint formed of an insulating resin and fixed to the other end of the first antenna element, a tubular feeding fixture formed of a metal, electrically connected with the holder by sliding and put in place sheathing the joint, and a second antenna element electrically connected to one end of the feeding fixture. The feeding fixture has a pressing process applied portion formed by applying an inward pressing onto the peripheral thereof and the feeding fixture and the joint are coupled with each other at the pressing process applied portion. The manufacturing method of the antenna has the steps of putting in place the feeding fixture that sheathes the joint and applying an inward pressing process to the periphery of the feeding fixture, thereby coupling the joint and the feeding fixture together.

Antenna and its manufacturing method

A helical coil and a top-helical type antenna using the same, wherein the helical coil has a plurality of either substantially U-shaped or nearly V-shaped branch portions made of a thin metallic sheet material. The branch portions are connected continuously in a manner to place their open ends alternately inversely, and the branch portions alternatively curve toward an obverse side and a reverse side of the metallic sheet to form each turn of the coil. A method for producing the helical coil includes continuously die cutting a member on a belt-shaped strip of electrically conductive metallic sheet, and alternately placing a plurality of either substantially U-shaped or substantially V-shaped branch portions with their open ends inversely. These substantially U or V-shaped branch portions are then connected with each other in the shape of a letter, with connection to the metallic sheet being held only by linkage portions at opposite sides. The helical coil is formed by alternately curving the branch portions of each of the members in a shape of substantially circular arc toward an obverse side and a reverse side of the metallic sheet. A bobbin is formed connecting each turn of the helical coil by either insert-injection molding or outsert-injection molding of electrically nonconductive material on the individual helical coil formed on metallic sheet and subsequently the linkage portions are sheared off of the metallic sheet.

Helical coil, method of producing same and helical antenna using same

Growing community of inventors

Osaka, Japan

Kazuji Ota