Roller door apparatus

Door apparatus comprising:

• a roller, means journaling the roller for reversible rotation about a central longitudinal roller axis, an end rail for reciprocable movement in a linear path between a first position in adjacent relation to the roller and a second position away from the roller, a flexible curtain for closing a door opening in the second position of the end rail and having one end secured to the end rail and having an opposite end portion secured to the roller to be wound on the roller during movement of the end rail from the second position to the first position and to be unwound from the roller during movement of the end rail from the first position to the second position, a reversible, variable-speed electric motor drive coupled to the roller and operable in a servo configuration, a solid state electrical controller for varying the speed of the motor drive during each movement of the end rail in either direction for rapid acceleration of the curtain to a high speed during an initial portion of each movement and for control of deceleration of the curtain to zero velocity during a final portion of each movement, and further including releasable latch means for latching the end rail in the second position, the electrical controller controlling the electric motor drive to rotate the roller in a direction to apply tension to the curtain after actuation of the releasable latch means to the latching condition.