Abstract: A support structure or ground sleeve for supporting a pole including a cap threadably engageable with an open end of a sleeve body. The ground sleeve includes a sleeve body adapted to be positioned in a ground surface for receiving and supporting a pole and includes at least one flange extending outwardly from the sleeve body for preventing the sleeve from rotating in the ground, a collet for engaging the pole, and an inwardly tapered closed end of the sleeve body for centering an end of the pole. An inwardly tapered race surface of the cap and a plurality of cirumferentially-spaced tabs of the sleeve body cooperate to define the collet. In addition, the ground sleeve is formed of a weather resistant non-corrosive material.

Abstract: A roll-up door has a bottom bar attached to the flexible curtain of the door. The bottom bar has transverse openings at each end adjacent to the jambs of the door frame. A breakaway shaft travels in a track in each jamb and has one end normally seated in a respective transverse opening by the interaction of spring loaded ball detents and detent recesses in the shaft and bar. The opposite ends of the shafts are connected to a counterforce mechanism that urges the shaft downwardly and are also connected to a strap wound with the curtain drum to urge the shafts upwardly against the counterforce. The breakaway shafts will separate from the bar upon impact to free the bar from engagement with the jamb and prevent damage to the door. The breakaway shafts may then be reconnected with the bottom bar and reset by unwinding the curtain to an overtravel position that is beyond the normal closed position of the door.

Abstract: A roll-up door has a bottom bar attached to the flexible curtain of the door. The bottom bar has transverse openings at each end adjacent to the jambs of the door frame. A breakaway shaft travels in a track in each jamb and has one end normally seated in a respective transverse opening by the interaction of spring loaded ball detents and detent recesses in the shaft and bar. The opposite ends of the shafts are connected to a counterforce mechanism that urges the shaft downwardly and are also connected to a strap wound with the curtain drum to urge the shafts upwardly against the counterforce. The breakaway shafts will separate from the bar upon impact to free the bar from engagement with the jamb and prevent damage to the door. The breakaway shafts may then be reconnected with the bottom bar and reset by unwinding the curtain to an overtravel position that is beyond the normal closed position of the door.