Tonewheels from a Robb Wave Organ

In researching an upcoming project tentatively called “Mechanically Infinite Devices”, I’ve been spending a lot of time reading about tonewheels.  Most rely on a simple metal disc with spurs (sort of like gears) and an electromagnetic pickup (like in an electric guitar).  The Robb Wave Organ, however, is a slightly different case.  The organ features similar rows of tonewheels, but with patterns cut into the wheel’s surface.

There’s something intricate and careful about this design.  Even the patent application (detail below) is wonderfully designed.

A detail of the Robb Wave Organ patent