Patent ID: 7178638

Claim:
A car door apparatus of an elevator, comprising: a pair of door panels that open and close a doorway of a car of the elevator; a door drive device that drives the door panels to open and close the doorway by using electric power; and a door-opening mechanism that starts up the door drive device by using a secondary battery to move the door panels in the opening direction by a predetermined distance respectively to make a predetermined clearance between the door panels when the car is stopped in an emergency causing the electric power for driving the elevator to be shut off, wherein: the door panels move along door rails provided at the car, said door rails have lower steps and upper steps divided by slopes, said lower steps are formed at the middle portion of the door rails, and said door panels in the closed state climb over the slopes to move from the lower step areas to the upper step areas to open the doorway, and the door-opening mechanism generates a driving force to move the door panels, said driving force being set to be smaller than a climbing force that is required to make the door panels climb over the slopes.