Windscreen wipers were patented in 1903 by Mary Anderson, an Alabama woman who was traveling in a trolley car during a winter storm. She was horrified by how snow and sleet obscured the two-paneled windshields of the vehicles. She tried to interest manufacturing firms in her invention, but didn’t get any takers. Today, the wiper blades on your car are attached to a plastic arm that either hangs straight or is hooked.
Beam Blades
In high windy conditions, windshield wiper blades can experience a problem called wind lift. This happens when the rubber blade lifts off the glass, causing the wiper to lose contact with the windshield. Premium beam blades resist this by converting wind resistance into windshield pressure for optimal performance in any weather condition.
Conventional blades have a rigid metal frame with multiple spring-loaded contact points on the windshield. These contacts clog easily with ice and snow, making them less effective during extreme weather conditions. In contrast, premium beam blades have no exposed parts to clog or break.
Beam wiper blades are usually a high-strength tensile steel beam wrapped in an aerodynamic rubber spoiler. They look sleek and stylish on your car’s windshield, but the real beauty is in their exceptional performance. They have a memory curve that conforms to the curvature of your windshield for more even wiping. They also have a higher number of pressure points that hug the windshield for a cleaner line of sight.
Intermittent Wipers
Before intermittent wipers, drivers had to continuously pull the lever to clear their windshield of rain or snow. But the intermittent setting, which allows the windscreen wipers to pause briefly between sweeps, is now standard on almost every modern vehicle.
The intermittent wiper system typically uses a series of relays (typically three different ones) that send power to the wiper motor for its various speeds. Some of these systems also factor in vehicle speed to shorten the time between wiper sweeps. Relays are located underhood in the fuse panel or junction box, and they may be prone to failure.
Robert Kearns, PhD CIT ’64, credited the invention of intermittent wipers to an incident on his wedding night when an errant champagne cork struck him in the eye, blinding him in one eye. He presented his design to Ford, which accepted it and introduced the system on its vehicles in 1969. His long legal battle with Ford over the patent was dramatized in a 2008 film, Flash of Genius.
Variable-Speed Wipers
The variable-speed wipers feature a switch that is triggered by the sensor, so that the motor can run at the specified speed. This reduces the chance of chatter and prolongs the life of the wiper blades. This also improves the quality of lesser wiping strokes and allows the windshield to dry more quickly.
In this system, the drag of the wiper blades on the windshield exerts a braking force that varies with the condition of the windshield. The force is greater when the windshield is wet, and the system is decelerating more rapidly. In this way, the braking force of the wipers causes the motor to stop sooner during the decelerating period.
When the control knob is pushed to the intermittent position, switch 98 closes to reduce the value of the brake resistor 94 and switch 100 disconnects the variable resistor from negative voltage -B. When the movable contacts 76 and 92 engage, current flows from -B potential through the armature 165, field winding 172, and transistors 122, 124, and 126.
Linkage
Windscreen wiper linkages synchronize the movement of both windshield wiper blades on a vehicle. When a linkage breaks, the affected windshield wiper will stop working. This can lead to reduced visibility, and a lapse in driver concentration can make it difficult to react to changing conditions on the road. Fortunately, replacing windshield wiper linkages is an easy task. CARDONE wiper linkages are complete units that match OEM performance at a fraction of the cost.
A complicated system of rods and levers hidden under the hood helps turn the spinning motion of the wiper motor into a sweeping movement for the windshield. But this linkage can wear out over time. The best way to check if it’s worn is by looking at the couplers that connect the axels in your windshield wiper arm to the shafts of the linkages. Do they look fine or do you need to apply a lot of force to get them on?
Conclusion
Windscreen wipers need changing at least once a year. Haynes recommends you make this an annual event and put it in your diary. Wiper specialists sell model-specific wiper blades with a selection of plastic fitments such as hook, side-lock, top-lock and bayonet. You can compare these with your car’s existing wipers to see which are right for you.
