Abstract: A driving apparatus for a motor-driven telescopic antenna including a rotary force transmitting mechanism installed between a drive side component rotated by a motor and a driven side component that extends and retracts an antenna element when rotated. The rotary force transmitting mechanism includes two coil springs provided circumferentially on the drive side component and two ridges formed with a space in between on the driven side component circumferentially so that when the drive and driven side components are rotated the ridges pushes the two springs to make compression deformations successively.

Abstract: A drive control apparatus for an electrically-driven type extensible/retractable antenna comprises a control circuit connected to a power supply, a motor controllable by the control circuit to be rotated in a normal or a reverse direction, a multi-threaded type worm provided on an output shaft of the motor, a worm wheel engaging with the worm, a drive gear receiving a rotational force of the worm wheel to allow it to be rotatably driven, a drive rope having a rack in mesh with the drive gear and adapted to be moved in a longitudinal direction upon the rotation of the drive gear, an extensible/retractable antenna element driven by the drive rope to allow it to be extended or retracted, stopper means for mechanically stopping an extending or a retracting motion of the antenna element when the antenna element reaches an extension or a retraction limit, a shock absorber made up principally of an elastic member for alleviating an impact force by which the antenna element is stopped upon collision with the stopper

Abstract: A device for driving telescopic power antenna for vehicles including a drive cylinder connected to an antenna motor, a driven cylinder which is concentrical with the drive cylinder and controls the extension and retraction of the antenna when rotated by the drive cylinder, and a transmisson mechanism interposed between the drive an driven cylinders. The transmission mechanism includes a projection formed on the drive cylinder, a circular groove formed on the driven cylinder, a coil spring installed in a manner to expand and contract in the direction of the length of the groove, and a pair of arc shaped cores installed in the coil spring. The coil spring and the cores ae compressed by a specific displacement-pressure relationship when the projection moves along the groove and presses one end of the coil spring when a relative rotation occurs between the drive and driven cylinders.