| 摘要 |
PURPOSE:To eliminate the noise occurrence as well as to enhance the controllability not by using the clutch and the limit switch for the expanding and reducing actions of the antenna element but using the wheel engaging the worm attached to the shaft of the DC motor. CONSTITUTION:Worm 18 is attached to shaft 6 of motor main body 1, and wheel 24 engages worm 18. And wire driving wheel 25 is turned with the rotation of wheel 24 in order to give the expansion or reduction to expanding rod antenna element A. When the rotation of wheel 24 is stopped with end of the expanding or reducing action of element A, the shift of shaft 6 is allowed toward the axial center via holding springs 23a nad 23b. And when shaft 6 is held at the fixed position by springs 23a and 23b, the fixed positioning is secured for the 1st and the 2nd brushes B1 and B2 sliding the outer circumference surface of rectifier 7 as well as the 3rd brush B3 connected to power supply circuit 10. And brushes B1 and B2 are shifted to insulating circular substances 8 and 9 when the expansion or reduction is given to element A. Thus the positive and negative voltage of circuit 10 are applied to main body 1. |
