Rectractable pylon arrangement

摘要

A pylon or barrier arrangement which is recessed into the ground or other surface and includes a post-like pylon which is movable between an extended position for control of vehicular or pedestrian traffic, and a retracted position beneath the ground. Movement of the pylon is achieved by a linear-type drive mechanism which acts as a clutch by decoupling from an upright and rotatable smooth drive shaft during abrupt downward driving of the pylon to avoid damage to the internal components of the arrangement. A sealing arrangement is provided for preventing the entry of debris into the interior of the pylon arrangement, and a heating unit is provided for preventing seizure of the arrangement during harsh weather conditions.