Who invented indicators on cars?
Depending on the time period, cars have had various types of indicators, e.g.
- small interior light to indicate that electrics to engine switched on
- fuel gauges, visible to driver, indicating the amount of fuel in the tank
- speed indicators
- rpm dial
- fuel efficiency (mpg) indicators
- external air temperature
- braking indicators, visible from the rear
- turn indicators
- water temperature indicators
- 'door not shut' indicators
- 'seat-belts not fastened'
- 'system fault' indicators
In 1889 E. Martin was one of the earliest inventors/designers of vehicle braking indicators. His idea was of a board at the back of the car upon which the word STOP was written but hidden behind flaps. The action of using the brakes would open the flaps and those following could read the STOP notice.
In 1893 J. B. Freeman had a text-roller at the back of his car bearing the words
The roller could be rotated with a cord and pulley system to indicate to following vehicles the direction to which he was about to turn.
Around this time others were also making left/right mechanical arms that the driver could operate. The arms mimicked the use of hand/arm signals that drivers would otherwise have used to indicate the direction to which the car was about to be turned.
Around 1905 F. Berger added pneumatic power to these semaphore arms, which were also 'pneumatically' self-cancelling.
In 1907 a patent was applied for by Percy Douglas-Hamilton for his electrically lit 'hand-shaped' signs which would indicate the car driver's left/right intentions. The patent was granted in 1909. (U.S. patent number 912831)
With regard to the mechanical semaphore system, in 1908 Alfredo G. Barrachini (Rome) put small electric bulbs in the arms so that they glowed. Although primarily cable operated, the arms could also be moved/powered electrically.
Florence Lawrence (Canadian) also invented a turn indicator for cars in about 1914, but she did not correctly patent her invention.
- The device was called an "auto signaling arm" and it was attached to the car's rear fender. When the driver pressed a button an electrically operated arm raised a sign to indicate the direction of the turn.
In 1918 the Naillik Motor Signal Company (Boston) invented the first 'totally electric' signals, using small electric motors to move the arms.
In 1929 Oscar J. Simler (American) patented a turn indicator after stealing the invention from a northern British man.
In 1935 a company in the United States invented a flashing turn indicator.
A Buick was the first production car to be fitted with an electrical turn indicator in 1938.
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