| 摘要 |
PURPOSE:To simplify the constitution of an antenna expansion/contraction driving mechanism which moving up and down an antenna rod and to perform stable antenna expansion/contraction control by providing a driving pulley and a pre-loading roller. CONSTITUTION:The antenna rod 11 is set linearly movably in its axial direction in housing 30 and 31 which are coupled in one body. Then, a driving pulley 38 is provided coaxially and integrally with a worm gear 37 provided in the housing 30 and this driving pulley is rotated by a motor 40. The pre-loading roller 41 is set on the outer circumferential surface of the driving pulley 38 through the antenna rod 11 in contact. This pre-loading roller 41 set movably toward the driving pulley 38 or in a leaving direction to press the antenna rod 11 to the circumference of the pulley 38 by the elastic force of a spring 44 extending to an adjusting screw 43. Namely, the antenna rod 11 is moved up or down by a motor 40. |
