Remote control system for constructional machinery

Claim 1

In a remote control system for a construction machine: a command unit having a number of manually controlled circuits for effecting a number of different control functions; a multi-pole command unit plug connector, said command unit plug connector being electrically connected to said manually controlled circuits of said command unit, for establishing an electrical connection with said manually controlled circuits; a transmission unit; a multi-pole transmission unit plug connector, said transmission unit plug connector being electrically connected to said transmission unit; a receiver unit having an electrical distributor for generating electrical signals which actuate a plurality of solenoid control valves on a construction machine; a multi-pole receiver unit plug connector, said receiving unit plug connector being electrically connected to said receiver unit; a pair of line plug connectors having a line conductor extending therebetween; whereby said command unit is selectively connected through said plug connectors and said line conductor to one of said transmission unit and said receiver unit to effect wireless and wire remote control of said solenoid valves, respectively; said transmission unit including means for sending digitally encoded radio frequency messages for each control function which comprise a two-part message continuously transmitted after a connection has been made, such messages each having bits representative of the desired one of said number of control fucntions, address information, and a parity bit for security and mirroring the condition of said circuits of said command unit; and said receiver unit including means for receiving digitally encoded radio frequency messages, a central process controller connected to said means for receiving for receiving and decoding said messages, a D/A converter/amplifier connected to said process controller for converting the output of said process controller into analogue control signals and a plurality of relays connected to said converter/amplifier and responsive to said control signals for actuating a plurality of solenoid control valves on a construction machine.