One of our great founders here at the Autopian has made it his life’s work to call out the inadequacies of most of the current self-driving systems in cars. However, there is a bigger issue that seems to be getting worse in automobiles as many designs change to rear windows that are painfully short in height.
What’s with these tiny wipers?
source: CarsDirect
I mean, look at the area these things actually clean…it’s a joke. Sure, some people will say that rear view cameras, giant screens, and beepers make a rear window of any kind superfluous today. To that I say shut up the fuck up, Elon. I think MOST people want to look out through the backlight, and through more than just some dinky little arc when it’s raining/salt spray covered.
One option is to add more little wipers like on the windshield of an old MG or a Toyota FJ Cruiser:
Sources: ebay and The MG Experience
Or for a rear window, the Toyota Cressida wagon went all-in with twin wipers:
source: Japanese Nostalgia Car
Still, these are kind of clunky solutions. I want a big wiper that covers most of the window. Imagine never having to squeegee the backlight at a gas stop ever again.
So I looked at the mechanisms that are used INSIDE rear windows, for window shades and cargo covers.
You’re familiar with the scissor-type things that lift the rear window shades on fancy ass cars.
source: ebay
So the wiper would work the same way. I’m thinking two wiper arms that would sweep inwards like a Renault Alpine, but the arms would attach to the wiper “beam” in tracks so the beam would stay parallel to the window. Pretty simple mechanism, and it pushes down so heavy snow would have gravity on its side, and the ‘beam’ would park in the upper lip/duck bill most cars have above the window.
The unit could utilize standard wiper blades in standard sizes…just whatever two or three across standard sizes would fill the space (maybe overlap to eliminate any lines). It MIGHT need internal springs or something to center the wiper – remember the sunshade will self-center because it is a roll.
But see below how it cleans all visible opening on the window:
Another idea for this would be a cable system like that one used on power cargo covers. These things work with an overlapping parallel cable thing that lowers and raises the cover with a motor mounted below that tailgate threshold.
source: 5series.net
Pretty clean and slick BUT I know how it works ONLY because an identical vehicle is in my garage now and it has broken…twice. Now, if Toyota did this instead of Munich, it might be better. Still, for outdoor use, with tracks that could fill with ice… I think the arm system might be better.
So, could either kind of mechanism create a full width rear window wiper? I’m a nerd but not an enginerd so I need your help! Tell me in the comments here if this is viable and deeply important or just madness!
Seems like the obvious answer is a trunk monkey with a squeegee.
https://www.youtube.com/watch?v=8avOiTUcD4Y
I mean, if you put that rear glass at more of an angle and thus make it taller without making the vehicle taller, you could just fit a longer wiper that covers a bigger area….. C6 Audi A6 comes to mind, or the 1999 Saab 9-3, which had a giant ass rear wiper.
It also makes the car’s profile look better IMO.
The 1990s Toyota Camry wagon had dual wipers as well.
playswellwithnothers
The 86-87 Honda CRX-SI had a giant wiper that spanned most of its large, very sloped rear window w/ a parallelogram mechanism that held the wiper mostly parallel to the sides of the window as it got wet/dirty
“To that I say shut up the fuck up, Elon.”
Incoming pedo tweet in 3…2…1… 😉
nemebean- I know! Why do you think I stay anonymous on this site?
I’d go with the 4 bar linkage common on buses:
https://www.schooltube.com/media/video-of-the-windshield-wipers-on-a-school-bus/1_kdac2xk3
basspaul- cool mechanism, but it requires way, way more height than you have to work with here.
We could turn it 90 degrees and mount it to the glass to not make the pillar larger.
Thank you Bishop, this is one of those thought experiments I’ve run through my mind a thousand times, how to have more efficient wipers at the front and the back. Love the design and can only hope someone would seriously take something like this forward into the real world. Keep it coming!
In The Mike Lane- I really don’t have the final answer. This is just one possible solution. The main thing is that I wanted to highlight what I think is a problem that is being ignored.
I’d kind of like to see someone try a spinning disc style windscreen wiper like on ships – has anyone ever done that on a car? It would solve the problem of the top speed setting never being quite enough for a heavy downpour and would also be more durable and lower maintenance. Though, it would involve a hole through the glass that would have to be sealed
https://www.alamy.com/stock-photo/colani-truck.html
Like this Colani truck! As I said earlier, it helps when the window is designed to match the wipers and not the other way around
“You’re familiar with the scissor-type things that lift the rear window shades on fancy ass cars.”
No, in truth I was completely unaware of them until reading this. I’ve now added them to my curmudgeonly automotive list of “damn things that’ll just break and need fixin’.” Thanks for the heads-up!
“To that I say shut up the fuck up, Elon.”
Lines like this keep me coming back daily.
Halftrack- for some cases, yes, but take a look at the image at the top of the article. That wiper would have to extend to over twice its length to clear the area, which would take a totally different kind of mechanism, if it would work at all.
For sure there would be some issues to work out, but there are fully sealed stepper motors available (https://www.jvl.dk/1062/waterproof-dustproof-stepper-motors) that are made to be used in harsh environments. Alternately a standard stepper motor could be used, but contained in a weather-sealed housing, or entirely within the vehicle where only the spindle passes through to the outside.
Since the vehicles where the small wipers are a problem by design have small windows, there may not be tremendous leverage on the non-drive end of the wiper. There could certainly be a mechanism made that normally keeps the wiper in the proper orientation but allows some flexibility if it does get hung up.
sorry double post, this should have been a response in a comment thread
You’re still thinking inside the box. Free your mind…..
-Flexible glass.
-Looped system that moves and cleans the dirty glass while exposing clean glass.
It would be like those awesomely terrible rolls of dangling towels at old gas stations. Do we have the technology to do it? Probably not. Is it feasible? Not even remotely. Does it sound like a Torch fever dream? Yes, and this is why it must be done.
There are also systems with electromagnets and high air pressure. These have been championed by Elon…I think that tells you all that you need to know.
There’s another option… long ago I added a very specific spoiler to the rear of a Pathfinder I owned. It changed the way air flowed over the car, and effectively eliminated the need for the rear wiper. I used that rear wiper all the time… any rain shower and the back of the vehicle was covered in a mist that needed cleaning.
The spoiler basically drove air coming over the top of the truck and down the rear hatch. The turbulent misty stuff didn’t accumulate anymore and I basically stopped using that wiper.
I’d guess this is very bad for aero, which is why none of the spoilers on hatchbacks I’ve seen move air in the same way. But maybe a little powered rain mode?
The sad truth is that more and more cars have a rear mounted camera which is displayed in the center rear view mirror which, in the mind of car manufacturers, negates the need for a rear wiper (or even a rear window, I guess).
Since the camera and its display are mandated when backing up, leaving it on all the time is “free”…
What I want to know it’s, why is it usually cars with small vertical windows that have these, instead of sedans and such that need it much more. I rarely need the rear wiper on my hatchback, whose window generally doesn’t get obscured due to its orientation and relative protection from the elements, but would love having one on the highly exposed and more horizontal (and thus water and dust collecting) window of my sedan–which doesn’t have one.
5th Earth- I think vertical rear windows pick up more dirt due to airflow? Old American station wagons used to offer a wind deflector on back of the roof rack to direct airflow over the glass and try to keep it clean.
” Old American station wagons used to offer a wind deflector on back of the roof rack to direct airflow over the glass”
That was designed to keep auto exhaust from coming in the back window when you rolled it down while driving. I’m sure it also helped with rain.
My Taurus sedans would clear themselves through aerodynamics except during the heaviest snows, so using air will work.
I would think that something that sweeps left to right, rather than up-down would be preferable. The main reason is that it could be much smaller and more easily be made to conform to the window than a large wiper in an up-down motion.
Another benefit would be that the stuff being swept off would follow a natural path down the window. On the up-down sweep that stuff would be dragged up the window on the upsweep, then not really have anywhere to go. Of course, a curved wiper blade would solve that but would make the down sweep more difficult to control.
Perhaps the left to right motion could be done with a worm gear and a rod, or a belt and stepper motor set up like a 3d printer. The drive mechanism and wiper could possibly be stashed within the spoiler.
https://patents.google.com/patent/US3428996A/en
here is a patent for something similar from a million years ago. This one involved a tailgate window that lowered and was then cleaned by a vertical wiper.
I think in principal the vertical wiper works but in practice it turns difficult. Stepper motors will run into issues in outdoor use. Plus the leverage created by objects further down on the wiper.
For sure there would be some issues to work out, but there are fully sealed stepper motors available (https://www.jvl.dk/1062/waterproof-dustproof-stepper-motors) that are made to be used in harsh environments. Alternately a standard stepper motor could be used, but contained in a weather-sealed housing, or entirely within the vehicle where only the spindle passes through to the outside.
Since the vehicles where the small wipers are a problem by design have small windows, there may not be tremendous leverage on the non-drive end of the wiper. There could certainly be a mechanism made that normally keeps the wiper in the proper orientation but allows some flexibility if it does get hung up.
Sunshade would work, but it would still need to swing. You’d get more coverage, and the kinematics would actually work (over time, cause your idea would work for a year before the linear compliance got borked).
“To that I say shut up the fuck up, Elon.“
That had me laughing 🙂
I never knew some cars had two wipers back there. Something is going to be needed soon, rear windows are starting to get like thin slits
i don’t think that will work on today’s curved windows. with the pressure points moving, even if the wiper is curved
ClutchRider- the other issue is that even if the wiper is curved, most windows likely are compound curved so that radius changes. I think it would not have to go right to the edge where the curving gets more severe. In all honesty, the rear window and curvature would need to be designed in conjunction with the wiper itself during the development of the car.
It might work if you let the mechanism itself work on a reasonably flat axis, and had the wiper blade heavily sprung on the outer edges, and only attached in the middle – especially since the rear window doesn’t have to have perfect visibility, just better than fully obstructed.
Still, I find my rear defroster helps out a lot at clearing out any kind of moisture.
Right now the biggest problem with rear wipers is that people ignore them.
Most have worn out/broken blades and many are turned on and forgotten.
Automatic wipers would probably make more sense in the rear and I like the idea of one that clears more area.
You’re quite right about nobody using rear wipers. Anecdotally, I’d guess maybe 1 in 20 clean late-model. crossovers in my area have that little plastic sleeve on their rear wiper blade running around town. A parked one I pass on my way to work has the plastic on almost always: it’ll get ratty, then very occasionally I’ll see the cuv without it for a few days before she takes it to the car wash again to get another sleeve.
Many cars will automatically turn the rear wiper on if you have the fronts on and shift into reverse. It surprised me the first few times I had it happen. Pretty handy tbh.
Why not just make the rear glass a usable height?
Hammerhead- I heard one car company spokesperson say that ‘people like the smaller windows and more sheet metal since it makes them feel safer’. What a line of crap.
The trend now continues to be thick C pillars and tiny rear windows, or massive four foot tall pieces of glass at an angle so the visible area out back is like 8 inches tall
Both my cars are big tall ugly things with lots of glass area and I can’t tell you how much more safe my wife and I each feel being able to…you know…see out of them.
‘people like the smaller windows and more sheet metal since it makes them feel safer’.
Drivers feel safer when they can’t see overly large vehicles with poor visibility on the road with them while the other driver’s head is angled down at their phone 75% of the time. Are we better off not thinking about it?
I’m a car guy through and through, but a lot of modern trucks and SUVs have hoods coming close to the roofline of my family car! Their bumpers definitely don’t line up with mine!
First of all, styling, and second of all, safety standards. The roof has to be able to support a certain multiple of the vehicle’s weight, and it’s easier and cheaper to do that with thick pillars and small windows.
The problem with the scissors is debris could get into the scissor part and essentially turn it into a giant pepper grinder. Can’t imagine it’d be good for the tracks.
Razoe- agreed. But that is one reason why it parks under to spoiler, so that tree needles and shit will tend to not collect there
I’d be more concerned about ice, if one arm gets frozen or it hits an ice chunk on one side the whole thing would twist, then you’re f*cked
Maybe there could be an integrated heating element in the housing under the spoiler and it would have a relay switch that doesn’t permit the scissor wiper to run if there’s a excessive resistance.
Src248- absolutely. Again, why I want this thing to park way up under the spoiler except for when it wipes down. The ice chunk thing maybe a resistance sensor like on hatchbacks and power windows?
To be fair, this is absolutely a problem with regular wiper systems too. Ice can wreak havoc on those, maybe even moreso since the long blade creates a lot of leverage.
This was my point. Living snow country, this has the potential to get cloged with ice, snow, road grit, etc.
The idea is solid for pure rain and I like where is going.
mrcanoehead- yes, I know about that system. But that works on taller expanses of glass. Looking at the proportions of the not-very-tall rear windows on cars today I don’t think that would work.
the extension of the wiper on the Mercedes system (at least on our old w140) it only extended six inches or so. This would need to more than double it’s length to get to all the areas.
actually, the w140 had two wipers but the outside one extended like that. In fact I think the one on my e61 does as well and I totally forgot about it.
With the current trend of hiding the wiper in the spoiler, the sunshade system seems perfectly suited to the cars of today. Would be great to see it.
Tiny little rear wipers on crossovers totally to me underscore the compromise/non-authentic nature of these vehicles.
Since vehicle C pillars are getting completely huge due to safety requirements, how about a vertical motor setup on the drivers side? Would allow standard blades to be used (the arm would just come from the side instead of the current bottom or top).
No mention of the Mercedes single wiper system that went up across and down on a linkage system? I rode in an old Merc that had one of those a couple of weeks ago and it was fascinating to watch.
https://www.youtube.com/watch?v=LdNu113Ep2U
Came here to say this. Surely this is the way. We already know it works.
Wasn’t aware of the merc system, quite inventive. Having had an Isuzu Impulse with a single wiper on the windshield, I can say it was impressive to watch. It literally did cover most of the screen, but left large upper corners uncovered that at times was disconcerting. But when that thing was on its highest setting, it went so fast to be able to cover the whole screen you thought it would fly off at any minute.
I found that video to be quite mesmerizing.