ELECTRIC DOOR LOCK REQUIRES NO KEY (Nov, 1936)
This seems like a poor design. Wouldn’t you want to put all the lock and bell mechanism on the inside of the door to prevent tampering? Also a combination lock with “dozens” of possible combinations does not exactly inspire confidence.
ELECTRIC DOOR LOCK REQUIRES NO KEY
No key is required to operate a novel electric door lock, recently exhibited in Chicago, Ill. The user merely has to push the right buttons selected from a circular row of eight, resembling a telephone dial, and the door will open. Pushing the wrong buttons not only fails to open the door, but sets off an alarm bell that rings for seven minutes. The owner can change the “combination” at will, and dozens of settings are possible.