| 摘要 |
An operating system for controllably moving in upward and downward directions a sectional door (D) in relation to a door frame (12) having a pair of jambs (13, 14) and an interconnecting header (15), including a counterbalancing system (30) having a drive tube (31) interconnected with the sectional door proximate the ends thereof, a resonible motorized operator (10) mounted adjacent to the drive tube and between the ends of the sectional door, and a drive train (70) interconnecting the drive tube and the motorized operator for selectively driving the sectional door in upward and downward directions. The operator includes a motor (40) for selectively rotating a drive shaft (60) in two directions, a drive wheel (80) on the drive shaft for rotating the drive train in one direction when the motor rotates the drive shaft in one direction, and a coupler on the drive shaft rotating the drive wheel when located in a first position and directly engaging and rotating the drive gear in the other direction when located in a second position. |
