An autogyro flies via autorotation of the unpowered main rotor.
A quadcopter allows simple, stable control without the need for varying the rotor pitch.
A tiltrotor can face its rotors horizontally or vertically for speed or lift. The aircraft has fixed wings to provide lift when the rotors are facing forwards.
This invention at first looks just like a quadcopter and is easily capable of vertical take off and landing. However, when at an acceptable altitude, two of the rotors tilt forwards, and the other two disengage from the engine.
The front facing rotors provide thrust while the freewheeling rotors provide lift via autorotation.
No fixed wings means greater efficiency for vertical takeoff.
Lift like an autogyro means safe landings are possible in the case of engine failure.
Top speed should be (at least slightly) greater than a quadcopter. Probably best suited for intercity travel and rescue missions.