Patent ID: 8111203

Claim:
An antenna apparatus, comprising: a support member which has a bearing hole; a drum which is rotatably supported by the support member and whose outer circumference corresponds to faces of a polygonal column; a case which covers the support member and the drum and which has a hole along a circumference direction of the drum; an antenna rod which extends from the outer circumference of the drum in a direction perpendicular to an axis of the drum toward an outside of the case through the hole of the case; polyhedral faces which are provided inside the case and which are to be fitted into the outer circumference of the drum; a shaft member which is embraced by the drum and inserted into the bearing hole of the support member, and which supports the drum rotatably with respect to the support member; a stopper ring sandwiched between the shaft member and an inner face of the drum; a screw shaft disposed to the antenna rod extending from an end of the antenna rod on the drum side; a shaft disposed to the screw shaft extending from a tip end of the screw shaft; and a flange disposed to the shaft; wherein: the drum has an insertion hole penetrating the drum in the direction perpendicular to the axis of the drum; the shaft member has a screw hole penetrating the shaft member in a direction perpendicular to an axis of the shaft member; the screw hole and the insertion hole are arranged in a row; the stopper ring is sandwiched between the shaft member and the inner face of the drum at a periphery of the insertion hole; the screw shaft passes through the insertion hole and is configured to be screwed with the screw hole; the shaft passes through the stopper ring; and the flange is configured to be fixed by the stopper ring.