Automatic door opener

摘要

A door is provided having an automatic opening means for the door and a key locking facility for mechanically locking the door in a door closed position and electric circuit means connected with the motor means to sense a change in the electrical operating conditions of the motor above that which is normal for operation of the motor and to remove the above normal power thereby supplied to the motor in such circumstances. The sensing means preferably comprises a means which switches off the power once the electrical operating conditions are sensed above that which is normal and whereby it returns the power some time later and should the motor then reexperience electrical operating conditions above that which is normal the sensing means will again switch off the power to the motor. The sensing means desirably comprise a bimetallic cut out switch means.