Jonathan Edward Caldwell - Cyclogyro

Cyclogyro

In February 1923 Caldwell filed for a patent on a device he called the "cyclogyro". It consisted of an airplane fuselage with two paddle-wheel like attachments in place of the wings. The wheels were powered by an engine in the fuselage, spun to power the upper portion of the attachments forward – clockwise, as seen looking left from the cockpit. The wheels each featured four high aspect ratio airfoils, which were able to rotate around their horizontal axis in order to change their pitch.

By changing the pitch continually through the entire rotation, the lift of the airfoils could be tuned to produce thrust in any direction. For instance, to lift off vertically the airfoils were pitched to have a positive angle of attack only at the top of their rotation, just generating lift only at that point. In forward flight the angle at the top of the arc would be reduced to make the lift neutral, but they would retain their positive angle even through the forward part of the circle, producing forward thrust. By changing the angle in this fashion, the aircraft could be "lifted" in any direction, with differential thrust between the two "wings" allowing yaw to be applied.

Caldwell formed Gravity Aeroplane Company in Reno, Nevada (Caldwell was living in Santa Monica at the time) and issued stock in 1928. Their company stationary included an illustration showing the cyclogyro, a version with four airfoils per "wing", attached on the fuselage end to a large disk and the outer end to a cross-like support.