Technical Curiosities:
Mercedes’ Monoblade Wiper
I’ve been captivated by this thing ever since I was a kid. Is there any more fun car activity on a dreary, drippy Tuesday afternoon ride home from school than trying to find a mid-’80s Mercedes E-Class or 190E just to catch a glimpse of the wiper in action? There is? Well… I enjoyed it.
Attempting to achieve a cross between the coverage of two blades and the economy and aerodynamic advantages of a single blade, Mercedes’ Monoblade (also known as “eccentric clean sweep”) certainly wasn’t the first single wiper system on the market. Cars as varied as entry-level Fiat econoboxes, sporty VW Sciroccos and high-end Jaguar luxury sedans preceded it with their solitary blades. What made the German automaker’s wiper system unique was the hub mechanism used to increase the wiper’s coverage of the windshield beyond a simple arc.
As illustrated above in the “single arm (controlled)” drawing, the Monoblade’s substantial coverage was achieved by designing it to extend outward toward the corners of the windshield in the course of its travel across the glass. A cam-type device in the hub moved the arm away from the pivot twice, retracting it in between so the wiper would not overextend the top of the windshield. It all sounds ungainly, but to watch it in action is to witness a quasi-mesmerizing symphony of mechanical fluidity. Call it odd, but I’m transfixed whenever I see a Monoblade going through its paces on a rainy day. I nearly have to wrench my attention away from the spectacle in order to focus on the task of driving my car.
Introduced on the pioneering W201 190E model series and also fitted to the W124 and W210 E-Class generations as well as the W202 C-Class, the Monoblade’s primary advantage was aerodynamic, as it noticeably cut wind resistance at high (read: Autobahn) speeds. Even though it seemed more simple, with one linkage instead of two, as in a traditional wiper system, the Monoblade was actually more expensive to produce and repair, owing to the number of specialized parts. Additional disadvantages included the difficulty for owners in finding the required long replacement blades and a slight, but decidedly non-luxurious rocking motion introduced to the car when the big wiper was operating in high-speed mode.
Watch the clip below to see the wiper in action, and be on the lookout for an older C- or E-Class next time it rains. You’ll get a treat.
Editor’s note: This post is part of an ongoing series spotlighting obscure automotive engineering solutions. Read the other installments here:
The thing was so heavy it rocked the car? Reminds me of the triple expansion engines of the 400 foot long ferryboat Badger on Lake Michigan.
I recall attending the long-lead press intro for the 300E in deepest Bavaria, and thank goodness it rained, so we all had a chance to see this clever device in action. Watching the arm extend and contract as it sweeps makes rain driving fun. My ’95 (E320 Wagon) was, I think, the last year with this feature. The only factoid that I recall from that press intro is that the wiper covered 86 percent of the windshield area. I remember being so fascinated that–to the wonderment of the MB PR guys–I took a car out in the rain and photographed the wiper in action!
It’s a real shame they’re not using them anymore. Neat piece of tech.
I justbought a 1999 e320 wagon, and it has a monoblade. I just noticed it and had to check online as I was worried I’d missed a missing blade when i looked the car over. So they were still using it on 99′ at least. Now i can’t wait to drive it in the rain. What a nice car!
Felicia, thanks for your comment! Glad you can be entertained while driving in the rain now. :) I’m envious!
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The mono blade wiper was not introduced in the W201 (190E). When the W201 debuted in late 1982 in Europe (North America got it during 1983 for the 1984 model year), it had a simple-arc wiper. When the W124 debuted in late 1984 (North America got it during 1985 for the 1986 model year), it debuted the mono blade wiper. The W201 (190E) went through massive chassis revisions (unseen from exterior) right when the W124 debuted to mimic W124 design, the W201 finally received the mono blade wiper in 1985: North America got this update sometime in 1985-1986 for the 1986 model year but only after the W124 had made its world premier.
It was no better than the opposed wipe two blade system. The opposed wipe two blade system wipes more of the corners,. It doesn’t wipe the center top, but no one looks through that area anyhow. That’s where the rear view mirror is.