| 摘要 |
<p>A retractable motor-driven antenna (10) of compact size and light weight capable of being supported at the top of a support tube (14). A molded plastic housing (12), (30) in part forms the drive motor. A drive transmission (34) for extending and retracting the antenna mast (15) uses a timing belt (78) and pulley wheels (61), (62) and includes an overrunning clutch (84) or energy storage and release interconnection (76) between a driven pulley wheel (62) and a hub (64) that drives a flexible cord (46) connected to the antenna mast. A switch assembly (32) within the housing includes a transducer (99) which senses rotation of the hub (64) and automatically stops the drive when the mast reaches its extended or retracted position or is obstructed.</p> |
