Abstract: A rocking cradle is provided which allows for a hanging cradle contained within a supporting frame to be aided in its cyclical transverse displacement by magnetic attraction and repelling forces. Central magnets are mounted on the hanging cradle and are attracted and repelled by a pair of magnets mounted on the supporting frame with one of the magnets being fixed to the supporting frame and the other magnet being rotatively displaceable with respect to the first magnet. Transverse displacement of the hanging cradle causes pivoting of one of the magnets on the supporting frame which then allows a repelling force from the stationary magnet to act against the magnets mounted on the hanging cradle to displace the hanging cradle away from the magnets on the supporting frame.

Abstract: A visitor sensing device capable of being combined with a conventional door intercom is provided. The device includes a detecting circuit to be installed adjacent a door of a house, for sensing the presence of a visitor standing in front of the door for a preset period of time. Responsive to detecting a visitor, the detecting circuit sends a signal to a converting circuit. The converting circuit converts the signal received from the detecting circuit into a monostable pulse to be fed to a vision circuit, which then displays an image of a visitor on its screen and also actuates an audio circuit. The audio circuit includes a buzzer to generate an audio signal.