The carveshop.com Numechron Digital Clock design was inspired by the Pennwood Model 1364 digital clock. Clocks of this type originated in the 1930s, and were built for many years by the Pennwood and Lawson companies in many different wood, metal, and plastic case styles.
I really liked the Art Deco style of the Model 1364 case and chose to emulate it, although my clock is considerably larger than the prototype. While mimicking the original style, I employed considerable open space in the case design so that the clock's internals would be visible.
A Pennwood employee, F. Greenewalt, patented the mechanism for this type of clock in 1935. He developed an ingenious set of wheels, cams, and levers to flip the numerals and operate the clock. I consulted the original patent to design the mechanism for this clock.