Windshield Wiper

Background

Windshield wipers are used to clean the windshield of a car so that the driver has an unobstructed view of the road. A typical wipe angle for a passenger car is about 67 degrees. The blades are 12-30 in (30-76 cm) long with lengths increasing in 2-in (5-cm) increments.

History

The history of the windshield wiper began with the invention of the automobile. Most transportation vehicles did not have wipers. Horse-drawn carriages and trucks moved at slow speeds, and glass was not needed to protect the driver or passengers or to act as a windbreak. The first windshield wipers were brushes. Inventor J. H. Apjohn came up with a method of moving two brushes up and down on a vertical plate glass windshield in 1903. In the same year, Mary Anderson devised a swinging arm that swept rain off the windshield when the driver moved a lever located inside the car. Anderson patented her invention of the mechanical windshield wiper in 1905, and it became standard equipment by 1913. Electric motors were not used yet to power automobile essentials or accessories, and Anderson's device had a drawback. Without another power source, a driver had to use one hand to move the lever. The driver's other hand steered the car (with either a wheel or steering tiller) and worked the stick-mounted gear shift and brake grips standing on the floor of the car or outside the driver's side on the running board. Rubber strips replaced brushes as the cleaning tools on wipers in 1905. Unfortunately, the hazardous need for drivers to wipe windshields while driving was not eliminated until 1917. The solution was to use an electric motor to move a single wiper with a long rubber blade back and forth. Hawaiian dentist Dr. Ormand Wall invented the automatic wiper by placing an electric motor in the top center of the windshield so the wiper arced down over the hood of the car in a semi-circular or rainbow shape. Wipers were one of the first electrical devices in automobiles after the electric starter was developed in 1912. Most wipers on cars before 1930 were paired and hung down from the top of the windshield. They were moved to the base of the windshield as electrical systems became more complicated. Windshield washers were added to the wiper on/off levers, and these required spray nozzles in front of the windshield, a tank for washer fluid in the engine compartment, and electrical connections to coordinate these operations. In 1962, Bob Kearns invented the intermittent wiper with intervals and speeds that the driver could change. The advent of electronic systems with fuses and circuit breakers to operate, regulate, and coordinate electrical components expanded the possibilities for more diverse wipers. Wipers were added to headlights in the 1980s, requiring connections between the lighting and wiper systems. In the 1990s, microsensors were built into windshields to detect rain on the windshield, activate the wipers, and adjust speed and intermittent use for the amount of rain.

Raw Materials