Back in 1971 I went to collect my new company car and as I drove out of the showroom in a heavy downpour, one of the windscreen wipers shot off and disappeared into the peak hour traffic.
That’s the thing with wipers.
If they work, as they usually do, they still leave a lot of glass unwiped because they operate in a sort of semi-circular way.
They’ve nearly always been that way, based on pretty dated technology.
The earliest wiper dates back to 1896, when George J. Capewell of Hartford, Connecticut, came up with his automated , motorised, wiper for “cars, locomotives, and such land-vehicles.”
However Mary Anderson, another American inventor, is popularly credited with devising the first operational windscreen wiper in 1903.
Her “window cleaning device” for electric cars and other vehicles was operated via a lever from inside a vehicle.
Then, in 1917, John Oishei, whose Trico products are still going strong today, invented the ‘rain rubber’ wiper blade.
Little has changed in the last century.
Most wipers work on a twin wiper system, some have blades of unequal length, a few are single blade jobs, but all will leave an annoying streak if a minute bug or bit of foliage its trapped under the blade.
Now Tesla has filed a patent application for an electro-magnetically motivated windshield wiper blade, that it says would be both more efficient and offer superior longevity over conventional wiper designs.
Rather than a typical motor-and-arm arrangement, Tesla’s patent suggests mounting the wiper arm bases on blocks which move back and forth on guide rails.
Current running through coils in the mounting blocks would activate electromagnets, causing the blocks to move along the rails in an almost zero-friction arrangement.
Tesla’s drawings show both single and dual blades.
The patent, which was filed earlier in September and spotted by Road & Track, describes multiple benefits of this approach to a fairly mundane system.
For starters, this wiper design would be free of the parasitic losses common in conventional setups as power is expended to produce movement of the wiper arms and components in the motors themselves.
The electromagnetic system would also not need the power required to overcome friction in these components, as the blocks on which the wipers are mounted would essentially float over the guide rails, rather than rubbing against them, and cover a greater area of glass.
Tesla also has its eyes on longevity.
The lack of friction means less wear over time, resulting in more predictable, precise operation throughout the course of the Tesla’s service life.
This is especially important for the EV giant as it plans to roll out more advanced versions of its self-driving suite, which require excellent forward visibility for its cameras to operate effectively.
It remains to be seen whether this would have much (if any) impact on a vehicle’s power consumption on a large scale.
Owners of Teslas in sunny parts of the world would likely see very little benefit, but who knows what else Tesla can do for systems such as these that have evolved very little since their introduction?
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