Image Number 4 for United States Patent #5944609.
When manually closed, switches in pads select toy vehicles and the operation of motors for moving the vehicles in different directions and moving upwardly and downwardly (and rightwardly and leftwardly) a receptacle for holding transportable elements (e.g. marbles). When interrogated by a central station, each pad sends through wires to the station signals indicating the switch closures in such pad. Such station produces first binary signals addressing the vehicle selected by such pad and second binary signals identifying the motor control operations in such vehicle. Thereafter the switches identifying in such pad the motor control operations in such selected vehicle can be closed without closing the switches identifying such vehicle. The first and second signals for each vehicle are transmitted by wireless to all of the vehicles at a common carrier frequency modulated by the first and second binary signals. The vehicle identified by the transmitted address demodulates the modulating signals and operates its motors in accordance with such demodulation. When the station fails to receive signals from a pad for a particular period of time, the vehicle selected by such pad can be selected by another pad and such pad can select that vehicle or another vehicle. A cable may couple two (2) central stations (one as a master and the other as a slave) to increase the number of pads controlling the vehicles. Stationary accessories (e.g. elevator) connected by wires to the central station become operative when selected by the pads.