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Tesla has applied for a patent for a new electromagnetic windshield-wiper system

caranddriver.com

31–40 of 142 posts

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#31

The Mercedes Monoblade was my favorite design, although it was notoriously expensive and unreliable. https://99percentinvisible.org/article/behind-screens-windsh...

Unreliable how???

My family were a Citroen (hydropneumatic suspension ftw) family growing up, so we had a variety of 'monobladed' cars, the wipers weren't one of the unreliable parts.

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#32
post #6

This may be a stupid question but, is there a reason cars don't just have a single blade that goes straight across, rather than wiping in this arc motion? It seems like it'd do a much better job of wiping and avoiding streaks if it just went straight across.

There are a few reasons:

1) having a single attaching point for the wipers makes designing stuff around it more simple

2) accurate curved tracks that match windscreens are hard to manufacture, secure and keep in shape

3) Keeping constant force for all parts of the windscreen is much harder with a track (high and low spots, change the window screen, the track needs adjusting too)

4) standard bearings are much more simple to seal

5) linear bearing as a pain to seal

6) tracks are much harder to seal against the weather

7) tracks need more lubrication

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#35
post #30

OT: have you ever noticed that most scifi movies depict futuristic cars that can hover or fly but which still use traditional windscreen wipers. You'd have thought they'd add a force field that repels rain or a special coating but no, traditional wipers. Even Bladerunner 2048 did this.

Traditional wipers show up even in shallow-focus closeups of people in the car, and they're immediately recognizable without explanation. It's like the ridiculously big UI elements in movie computer interfaces: for the benefit of the viewers, not the characters.

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#36
post #3

Is like to see how this wears in practice. Guide rails in a road setting seem like they will get gummed up fairly quickly and degrade performance unless the entire system is somehow sealed. It’s great to see a push for innovation beyond powertrain and head unit, though.

First thing I thought of. Sliding tracks in a dirty environment are usually a headache, because of the big exposed bearing surface. There are solutions, involving bellows, seals, and such, but they're kind of overkill for a windshield wiper. Rotational bearings can easily be fully enclosed and lubricated.

Linear motors have been around for many decades, but are still a niche product. The first commercial linear motor application was as banal as a windshield wiper. It was the 1962 "Electrac by Kirsch®"[1], a linear motor for draw drapes. Back then, large commercial buildings like air terminals were first getting big curved glass areas, and people expected them to have drapes. The string and pulley systems were not good with curves. So Kirsch came out with a linear motor unit that traveled along the drape track and pulled the drape. Multiple motors could run on the same track, for very wide drapes, so it scaled up well. Worked fine, cost too much, had 120VAC in the track.

I once expected linear motors to be a big thing in robotics, but that didn't happen.

[1] https://books.google.com/books?id=bdgDAAAAMBAJ&pg=RA1-PA164&...

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#37
post #6

This may be a stupid question but, is there a reason cars don't just have a single blade that goes straight across, rather than wiping in this arc motion? It seems like it'd do a much better job of wiping and avoiding streaks if it just went straight across.

The Lotus Exige (and the Elise I believe) has a single blade. It might have to do with the unusual curvature of the windshield.

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#38
post #30

OT: have you ever noticed that most scifi movies depict futuristic cars that can hover or fly but which still use traditional windscreen wipers. You'd have thought they'd add a force field that repels rain or a special coating but no, traditional wipers. Even Bladerunner 2048 did this.

I'm going to guess its because they're giving us what we expect, and can make sense of. Most spaceships have big hot engines of the type you'd probably unlikely to see on an actual spaceship, but we've been conditioned to expect big engines, so that's what we get.

Also there isn't really time in a film to explain away not needing wipers, so rather than risk having audiences thinking theres bad special effects because the rain that's falling isnt also falling on the windscreen, they just put wipers on and be done with it.

It could also be that that futuristic car you saw flying in, and can still see partially in shot is just a bog standard car that they've dressed to look like a flying car.

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#39
If they want to have one single blade move back and forth, that's cool, but this seems like a bafflingly complex way to do it. What's wrong with a normal linear actuator? It's powered by a regular electric motor (something right in Tesla's wheelhouse), can be built very reliable, and is plenty efficient. There's no reason to build the Space Shuttle when people just want an electric car, and won't be able to tell the difference under the hood anyway. Maybe they want as many solid state components as possible for durability? Talk about diminishing returns...

No, my guess is that this is to lock down the patent so they own it (and as many other even vaguely plausible concepts as possible) and can wield it in patent battles with other automakers. More charitably, you could look at it as clearing as much land as possible so that 10 years down the line their engineers are minimally encumbered by patent concerns and can build whatever they want. Typical corporate R&D, and not particularly deserving of a Car and Driver fluff piece.

Re: Tesla has applied for a patent for a new electromagnetic windshield-wiper system

#40
post #30

OT: have you ever noticed that most scifi movies depict futuristic cars that can hover or fly but which still use traditional windscreen wipers. You'd have thought they'd add a force field that repels rain or a special coating but no, traditional wipers. Even Bladerunner 2048 did this.

I always think it's a bit incongruous to see them on the cockpit windows of airliners. Sort of like having a vacuum tube power supply for your computer.

(Two other solutions exist. One is spinning the window, you'll see it on ships. The other is making the window hot.)

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