Rolling ball clockA rolling ball clock is a clock which displays time by means of balls and rails.[1] HistoryThe rolling ball clock was invented by Harley Mayenschein in the 1970s. He patented the design and founded Idle Tyme Corporation in 1978, which manufactured these clocks from solid hardwoods. Later, a license on the patent was sold to Arrow Handicraft. In the 1970s and early 1980s, Mattel also made them under license. The following excerpts from a letter written by Patrice Gunville, the daughter of Harley Mayenschein, give some detail of the history of the clock:[2]
How it worksThe original design of the rolling ball clock has three main rails – two labeled for minutes and one for hours. The bottom rail represents the hours, the middle rail represents the minutes in multiples of 5 or 10, while the top rail represents single minutes 1 through 4. By adding the displayed values of the two rails one could get an accurate measurement of the minutes. For example, if there are eight balls on the bottom rail, nine on the middle rail, and two on the top rail, the time would read 8:47. An arm driven by an electric motor scoops up a ball every minute. Every five minutes, the top rail will dump and deposit a ball on the second rail. Every hour, the upper and middle rails dump and one ball is transferred to the bottom rail to increment the hours. At 1:00 all three rails dump their balls to the feed rail at the bottom. The original design used an AC motor to move the arm continuously at a constant speed of 1 RPM. Later designs branded "Time Machine" used a low voltage DC motor to spin the arm once at a faster speed, with a modified quartz clock mechanism triggering the motor to drop a single ball at the top of the track. VariationsThe original design used steel balls, while the "Deluxe" model sold in the 1980s was twice as big and had plastic balls instead. There are homemade versions of the design which employ a 9-minute top rail, with the middle rail representing multiples of 10. KinetiClocK for example, is the newest rolling ball clock design with a focus on simplicity, durability, and aesthetics. Arrow Handicraft also manufactured the coin clock, which used pennies instead of balls. See alsoReferences
External links |