I was looking at patents recently, because they show the internal workings of recent drives that have been introduced. This way, I can find out more about how they work, and the details are something which manufacturers seem to think most of their customers might find to be a bit boring. So as a result, only the most basic info is usually squeezed into the short PR blurbs that are published and then re-pasted everywhere. But…you didn’t come to electricbike.com for just basic info, right? You can get that anywhere with a quick Google.
I stumbled across a few interesting older patents, and thought our readers would find them amusing (I’m posting them as large as possible so you can see more detail). There is an old proverb that “There is nothing new under the sun“, and “Everything that is old is new again“. So…think about these patents the next time you read an advertisement about a new E-bike product that is “Revolutionary!”
Edit: after publishing this article, I received many links from our readers for additional E-bikes that were not well known. Thanks you all for your help!
1881 Trouvé Tricycle
This lever-drive tricycle was produced in 1877-78, but by 1881 the Coventry factory had upgraded the new models to a modern rotary pedal drive. This would have likely made the older lever-drives less expensive on the used bicycle market.
The only known drawing of this historic event was published in the French science magazine “Physique et chimie populaires” Volume 2, by Alexis Clerc, 1881-1883.
The similar “Ayrton & Perry” that is also from 1881 deserves honorable mention, but it does not have pedals.
1892 Graffigny Tricycle
Here is a link sent to me from endless-sphere member “Lock”: the 1892 Graffigny electric tricycle from the archives of “Eureka” the inventors forum:
Here’s a direct-drive rear hub-motor patent from Ogden Bolton in 1895 (Patent No. US552271). The rear hub is a very recognizable permanent-magnet direct-current (PMDC) radial-flux outrunner. It is brushed, rather than brushless, but…for an antique, it looks surprisingly modern. DD hubs remain relevant because they can be powered at very high watt-levels that would break bicycle chains, and they also remain one of the quietest drives, so I suspect they will survive in some form for quite some time.
No sooner had the idea of the new hubmotors become known, that the next step was needed to find some way to increase the power and efficiency by getting the motor to spin much faster than the wheel. This patent from 1896 (only a year later!) from Charles Theryc, shows a brushed planetary-geared hub-motor! The sun-gear is a 10T, the single planet-gear is a 24T, and the ring-gear is a 56T, for a total RPM reduction of 5.6:1
Here’s an obscure reference to an electric bicycle built in new York by James O’Brien in 1896. The small motor is located just under the seat, and it states a woven silk belt drives the hub of the rear wheel.
Patent US596272 is quite an exciting find…It’s from inventor Hosea W. Libbey in 1897, and it is a mid-drive! I don’t see any pedals, but they were not required for the patent application. Having the motor separate from the wheel means that the motor is free to spin much faster than the wheel, and sprocket/chain gearing can greatly multiply the power density of the system. This means that a smaller non-hub motor can provide as much power as a larger motor that is located in the wheel, which is then restricted to spinning at the less-efficient lower RPMs of the wheel (only 333-RPMs for a 26-inch wheel at 26-MPH).
Unfortunately, this particular mid-drive only spins at the RPMs of the wheel, however it does move the weight of the motor to the center of the bike. The motor is a permanent-magnet dual-stator axial-flux style, with the rotor being the central section with a stator on either side.
The brushes are “Item R” in the drawing. Brushed DC (of course), and the battery is located in the frame triangle. The drive is two rod-actuated cranks (as opposed to sprocket and chain), 180-degrees apart in phase. The rear wheel appears to be two side-by-side wheels that are closely attached, and they have bow-shaped “leaf springs” that are mounted crosswise, that provide a crude rear suspension, to add to the spring-suspended seat.
The second page features the same bike frame, battery, and motor, but…configured as a friction-drive over the rear wheel. A purist might argue that the lack of pedals on the drawing makes this an “electric scooter”, but it clearly uses two crank-arms, to which pedals could be attached (I suspect he wanted to avoid licensing the existing chain & sprocket patents). Beat me with a stick if you wish, but I will continue to call this an electric bicycle.
This is not a patent, but an advertisement for the British 1897 Humber electric tandem.
“The Humber Electric Tandem below, with four accumulators and an electric motor, plus pedal power from two riders, was exhibited at the Stanley Show in November 1897.”
This tandem électrique was an invention of the Frenchmen de Clerc and Pingault, and is ridden by the French bicycle racers Dacier and Jalabert. On May 22, 1897 this tandem rode one-kilometer in 57 seconds.
Here is patent No. US598819, granted to Gordon J. Scott in 1898. If you haven’t seen this one before from similar E-bike patent searches (doesn’t everyone do this in their spare time?), it may be because it was filed as an electric “velocipede”. It is somewhat odd, in that…instead of a battery, the pedals spin a generator (dynamo), and the power from that dynamo drives a small motor. I suppose it might be called a “series drive”?
I know of one recent project where the pedals turned a generator that charged a battery pack (there was no chain connecting the BB to the rear wheel). The rear wheel was powered by a motor, and it was hoped that the pedaling would extend the battery to much farther than a full battery charge would normally provide. That real-world experiment proved that it was a very inefficient design, and the design shown here…would be even worse.
Getting back to patents that actually work: Here’s patent US627066 from John Schnepf in 1899. The page shown here is the direct-drive motor that is concentric with a shaft that powers a roller atop the rear tire to make a “friction drive”. There is a second page in the patent that has a 90-degree geared reduction to allow the motor to spin much faster than the roller (which theoretically would help efficiency), so he was a creative inventor, but…it is the first design that has proven to be something that has continued to pop up the last 113 years because it is so easy for garage-builders to put one together.
A friction drive is the first electric bike system that I ever had. An ES builder called EVTodd designed a drive using the compact and powerful RC motors that had grown larger over the years, and had finally reached a large-enough size in 2010 where they were a viable option for driving an E-bike. This motor in the patent is a simple brushed radial-flux 2-pole / 3-magnet type, and even with the crude and simple materials of the day, it would have been capable of very high RPMs. This isn’t the earliest example of a friction-drive, but this one takes the form that modern friction-drives have proven will work well.
Here’s a picture of my personal friction-drive. In spite of it’s small size, I pump 36V X 30A = ~1,100W of power through it. I had to switch to a square-profile tread tire from a Beach Cruiser to get enough traction so that it wouldn’t slip at high power or when riding through a wet patch in the road.
I searched a little more, and found an incredibly modern non-hub mid-drive. Patent number US656323, by Aebert Hansel, applied for in 1899 and granted in 1900. It has two stages of reduction, and uses a frame-mounted jackshaft to power the left side of the wheel.
Here’s the bike that ES member “PaulD” used to win a major E-bike race in 2012. A small frame mounted motor in the triangle, driving a frame-mounted jackshaft, which drives the left side of the wheel. He could’ve used a larger motor with a lower Kv (RPMs per volt applied), but…that would have been larger, heavier, and less efficient:
And, as if the patent above was not enough, Mr Hansel also patented a chain-less friction-drive, where the motor and the Bottom-Bracket (BB) sprocket share the jackshaft connection.
Here is a link to the 1932 Philips Simplex E-bike from the Netherlands. Thanks to E-biker “Kulle” from www.pedelecforum.de for the link
This is a picture of the wonderful Dutch Juncker 1933 E-Bike. 80 years old, but…I would be happy to ride this today!
The next one I found was filed in 1938 and granted in 1939 (the year that WWII started), so it is understandable that it didn’t gain much notoriety at the time. It is Patent US2179418, from T.M. McDonald. It is noteworthy for three reasons. It is the earliest example I have found of a front-wheel electric hubmotor. Also, the battery is mounted centrally and very low, and this provides the best possible weight distribution (just like the 3rd Element eSpire). And lastly, it uses an induction motor, instead of permanent magnets. Due to the weak power of the common ferrite permanent-magnets of the day, using electromagnets in the stator and also the rotor would make this motor much more powerful than some of the previous electric bikes shown.
The next patent up is actually still quite a viable configuration. It’s Patent No. US2457430 from 1946 by Argyris Stefanos. A centrally-mounted cylindrical motor drives a 90-degree reduction, which then runs in-line with the bikes drive chain. The motors’ drive-sprocket is mounted to a freewheel that is built into the system so the motor isn’t back-driven when the power is off and the bike is pedaled.
I could see these being made today! I would mount the motor just in front of the downtube, near the bottom bracket…with the motor mounted lower and the drive sprocket on top, just high enough to miss the top of the chainring. This lower mounting would free the frame triangle to allow the largest possible battery to be mounted there.
1950 Tucker geared hub-motor. I’m not really sure how this geared hub is materially different than the 1896 Theryc patent shown above. It is a radial-flux, induction motor with brushes. It does use at least two planet gears (and possibly four), which is an improvement. Also, the planet gears are stepped, so they provide a dual reduction, which is certainly a performance improvement, since this would allow the motor to spin much faster than a single geared reduction.
Here’s a pic a 1975 Panasonic E-bike, which uses 24V of lead-acid car batteries. I suspect it is a bottom bracket drive that allows the motor to use the bicycles gears, but I am still looking for information about these. Thanks to E-biker “Kulle” from www.pedelecforum.de for the link.
This next E-bike was something that I wasn’t sure I should include, but this article is only about having a fun read, so…here goes: It’s from 1975, and it is patent No. 3884317, filed by Augustus B. Kinzel. It mounts the motor around the BB-spindle. I can only assume that any production model would use the bikes gears on the rear wheel, so I don’t know why that wasn’t included in the patent. 10-speed derailleurs were common in 1975 (five sprockets on the rear wheel), and such a feature would have made this the earliest example I could find of an E-bike that gives the motor the use of some gears to improve hill-climbing. And yet…it is not specified in the text of the patent.
The positions of the rotor-magnets are skewed, which reduces cogging (this is an annoying drag when the motor is un-powered and the permanent magnets are drawn to the steel teeth of the stator), so it would seem the designer was savvy enough about electrical devices to make sure skewed magnets were included in the drawing. However… I assumed the battery was simply not shown in the drawing, but it is worse than that…much worse!
If you look closely, there is a battery…a tiny battery just behind the seat. It is ‘theorized’ to be kept topped off by constant charging by two tiny dynamos, one mounted to each of the wheels (Items # 16A and 16B). These are the common dynamos that are driven by the bicycles wheels and are typically used to power a headlight! That’s right…this is an over-unity E-bike! To put it in modern terms, he is using regen to power the motor. It is intended to use a conventional sprocket and chain set, but they are not shown in the drawing.
This last year has seen a boom in modern Bottom-Bracket (BB) drives. Names as prestigious as Bosch and Panasonic have spent significant amounts of time and money to develop the best possible system for mass-production. They came to the conclusion that to get the best performance from modest power levels like 250W, a BB-drive that gives the motor the use of the bikes gears is the best way to go.
The gasoline crisis of 1973 started a decade of innovative thought, and at least one person came to the same conclusion as Bosch and Panasonic, and he did it years before computer-aided-design (CAD) was available to the average person. Patent No. US4030562 is from 1977 by Charles P.D. Davidson and Peter W. Leighton. It is a compact BB-drive with a cylindrical motor driving a 90-degree reduction, and it incorporates a freewheel so the motor is not driven when you pedal with the motor unpowered.
Here is a patent of a longtail mid-drive from 1981. The builder is Egon Gelhard from Koln, Germany.
This patent from 1982 from Amedeo A. Restelli is interesting. It is a front hub-motor, but even though it appears to be a geared hub (nothing special), it also incorporates a clutch and specifies that the mechanism creates a 2-speed transmission. First gear is the geared function, and when the clutch is engaged, the motor becomes a direct-drive. Items labeled 19 are the brushes, 20 is the commutator, 16’s are the permanent magnets, 22 is the sun gear, 28’s are the pins at the center of the planet gears, and 21 is the clutch. Items that are drawn as a large “X” are the cross-sections of bearings.
The Hercules company is based in Germany. Since 1938, they have been making kits and also turn-key powered bicycles that used single-cylinder gasoline engines that were attached to the left side of the rear wheel. In 1989, they introduced the “Electra”, which was an easy switch from a gasoline engine to an electric motor in the same place.
It definitely has a two-stage reduction. Here is a close-up pic of the cover. Here is a close-up pic of the chain secondary. Here is a close up pic of the 24V brushed motor. The pic below is courtesy of Hannes Neupert / www.ExtraEnergy.org Archive
In 1989 Sanyo produced the Enacle, which used NiCd batteries instead of lead-acid, and that was a big advance at the time. The model shown below is from 1995. Pic courtesy of Hannes Neupert / www.ExtraEnergy.org Archive
In 1990, Michael Kutter developed what some people feel is the first Pedelec (PEDal-ELECtric). It later came to be referred to as Pedal Assist System (PAS), where there is no throttle, but the pedaling alone causes the motor to assist the rider. The first production models were sold in 1992 under the Dolphin name for the Swiss company Velocity, but they did not survive.
Pic courtesy of Hannes Neupert / www.ExtraEnergy.org Archive
Here is the 1993 Yamaha electric bicycle, which included the now popular Pedal-Assist-System (PAS)
This entry is from the Flyer Bicycle company in 1995. It incorporates a BB-drive and a freewheeling chainring.
In my opinion, the modern era of electric bicycles started just after 1995, when the computer boom made powerful neodymium magnets mass-produced, which brought their prices down. Neodymium magnets have been around for a while, and they were used in the hard-drives that stored digital files. Once neo’s became cheaper, electric bicycle motors got a power boost that provided the type of performance that get’s buyers excited.
Another big influence was about the same time when cordless tools and laptop computers moved up to using Lithium batteries. The mass production of lithium batteries brought their prices down. The combination of strong Neo magnets and lithium batteries both becoming more affordable…that was the turning point between electric bike “history”, and our modern era.
Written by Ron/Spinningmagnets, November 2013