US Patent 9949435 Equipment protection using a grain tank level sensor

A grain tank level sensing system for a combine which harvests grain. The combine includes an upwardly open grain tank fillable with harvested grain and a cover that is displaceable for closing off the open grain tank. An actuator displaces the cover between an open and close position and either single or dual ultrasonic sensors continuously detect the level of grain in the tank and generate a signal proportional to the level of grain in the grain tank. A control system receives the signal from the ultrasonic sensors and generates an indication of the level in the tank to a monitor and/or disables the actuator to initiate the closing function when the grain tank is full.