Patent 4,067,111

This is an over engineered version of the common sand pendulum which is widely sold in various versions and sizes as an executive’s desktop toy ingeniously called the “Pit & Pendulum” (et. al.).  These sell for around $25.00 to well over $100.00 for a fancy one.  

The pendulum configuration is a simple Blackburn’s Pendulum; which is essentially a “Y” swing; the bob rotates in infinite planes and the top of the “Y” imparts an additional back-and-forth motion to the pendulum. A Blackburn's Pendulum is also commonly found in science centers where it is sometimes presented as a sand dribbling Lissajous curve demonstration.