Intermittent wipers

The inventor of intermittent wipers might have been Raymond Anderson who, in 1923, proposed an electro-mechanical design. (US Patent 1,588,399). In 1958 Oishei et at. filed a patent application describing electro-mechanical, thermal and hydraulic designs. (US Patent 2,987,747). Then in 1961 John Amos, an engineer for the UK automotive engineering company Lucas Industries, filed in the UK the first patent application for a solid-state electronic design. (See US patent 3,262,042).

In 1963, another form of intermittent wiper was invented by Robert Kearns, an engineering professor at Wayne State University in Detroit, Michigan. The road to his intermittent wipers began earlier, on his wedding night in 1953, when an errant champagne cork shot into Kearn's left eye, which eventually went almost completely blind. Nearly a decade later, Kearns was driving his Ford Galaxie through a light rain, and the constant movement of the wiper blades irritated his already troubled vision. He got to thinking about the human eye, which has its own kind of wiper, the eyelid, that automatically closes and opens every few seconds. Finally in 1963, Kearns put his idea into action, building his first intermittent wiper system using off-the-shelf electronic components. Kearns showed it to the Ford Motor Company, and proposed manufacturing the design.

In the Kearns design, the interval between wipes was determined by the rate of current flow into a capacitor. When the charge in the capacitor reached a certain voltage, the capacitor was discharged, activating the wiper motor for one cycle. After extensive testing, Ford executives decided to offer a design similar to Kearns’ intermittent wipers as an option on the company's Mercury line, beginning with the 1969 models. Kearns and Ford became involved in a multi-year patent dispute that eventually had to be resolved in court. A fictionalized version of the Kearns invention and patent lawsuit was used for the 2009 film Flash of Genius, which is billed as "based on the true story", but does not claim to be historically accurate in all respects.

In March 1970, Citroën introduced rain-sensitive intermittent windscreen wipers on their SM model. When the intermittent function was selected, the wiper would make one swipe. If the windscreen was relatively dry, the wiper motor drew high current, which set the control circuit timer to delay the next wipe longest. If the motor drew little current, it indicated that the glass was wet, setting the timer to minimize the delay.