This thread got me to thinking about the bicycle power mechanism, with a person astride a seat, pumping pedals attached to cranks. Did this mechanism exist prior to the invention of the bicycle? Presumably there is no technical reason why not; if the Professor could built one out of bamboo, I see no reason why the ancient Greeks or others could not.
Does anyone know of any ancient devices that used the bicycle mechanism to harness human power?
The elements of the mechanism existed prior to bicycles. The crank, toothed gears and belt-transmission all had uses in ancient machinery. But I don’t know if any one created a “pedal powered” device.
With a bit of loose interpretation of your question, I think we could coerce some designs of treadle loom, potter’s wheel, pole lathe, spinning wheel, etc to fit.
No, I am aware that human powered devices such as you described have existed for thousands of years. I am specifically addressing the bicycle mechanism.
OK, but by which of course you mean the modern bicycle mechanism. Early designs of bicycles had quite a diversity of drive mechanisms (or sometimes, none at all)
as ** Mangetout** points out, even BICYCLES didn’t habe bicycle mechanisms at first. The Velocipede and the Pedestrian Curricle had practically nothing, in fact. Some early bicycles had really weird gearing or reciprocating mechanisms. The “Penny farthing” bicycle had the pedals going directly to the wheel. Look at the history of the bicycle on the web.
I suspect that the first bicycle-drive mechanism on anything besides a bicycle followed its use on the bicycle itself.
Even if they DID use it for everything on Gilligan’s Island.
Yes, I am aware. I am only interested in the applications of the mechanism described in my OP. Why didn’t we see it before?
The same could be said of anything. Why didn’t we see anything before it was invented? - Because it wasn’t invented yet.
Not true. Many inventions are only possible because of other technological, social or economic advances. I don’t think the bicycle was held back by any of those. And it doesn’t seem on the surface to be a terribly arcane idea that couldn’t have occured to any bright engineer 2000 years ago.
Some of those parts would’ve been quite tough for an ancient engineer to make by hand, though. Gears are particularly nasty, as are circles.
The same mechanism would work with belts and pulleys, though the Antikythera mechanism suggests gears were not beyond the technology on the ancients. Look at some of the inventions of Hero of Alexandria in the first century BC, including a wind-powered organ, a vending machine and an odometer:
I’m frequently impressed with the things that Archimedes, Hero/Heron, and many other, doubtless forgotten inventors in the Classical World came up with, not to mention folks like Leonardo da Cinci, but I’m still not familar with any gear-and-chain mechanisms with pedals for the feet before the modern bicycle. There were foot-powered devices, but they were more like treadmills. (In the Brueghel painting “The Tower of Babel” you can see many such treadmill-powered cranes)
My point in my post above is that, if such a “bicycle” mechanism had previously existed, I think they would’ve aapplied it to the bicycle itself earlier on, rather than fumfering around for several decades before settling on it. The “Pennyfarthing bicycle” (The one in “The Prisoner” logo, with its ludicrously oversized front wheel) was developed to solve the problem of coupling force and pedal rate between the bicyclist’s foot and the wheel, and the “bicycle mechanism” is a different (and, I think, better) way to solve it.
I say lack of technology before the late 1800’s is the answer.
The stresses on the bearings and shafts for pedals, cranks, and rear axles of a bicycle are pretty high for any rider putting out significant power. I think they’d be difficult to make without decent-quality steel. Even when good-quality steel existed, it was very expensive before the late 19th century. Precision metalworking (for bearings, gears, etc.) before modern machine tools was even more expensive (and I’m not sure if the technology to make ball bearings even existed at all before the 19th century).
So someone could have made a cycle-powered mechanism, but it would have been either so fragile that a simple hand-crank could put out more power, or so wildly expensive that it would be cheaper to just buy more slaves to turn simple hand-cranks. For bicycles themselves, a horse or slaves+sedan chair would be cheaper, even including the room & board of the horse/slaves (and the bicycle would be far less useful except where there were very good roads).
People are no smarter now than they were 1,000 years ago. In pretty much every invention that I’ve looked at, it was invented within a couple decades of there being the technology and economics for it.
On the other hand, people are now making interesting pedal-powered devices, for use in remote areas where electricity is expensive and unreliable: http://www.mayapedal.org/
But a bicycle crank is just a hand crank with a pedal added. If you keep the pedal off, you could just use the crank and your foot.
I don’t think a gear and a chain drive wou;ld have been beyond the abilities of Roman engineers – they built enough geared mechanisms (although I think they’d be more likely to build a gear-to-gear-to gear system, rather than a gear-chain drive). But they didn’t have a really good reason to do it.
Roman roads were so good that many still survive. They were well-built*. But they weren’t flat. (I’ve been on Roman roads) They were about as good as cobblestone streets.
Now imagine riding a bicycle on a cobblestone street. On the rims, with out pneumatic tires. In the ancient world, they didn’t have latex rubber, and they didn’t have polymers as substitutes. They didn’t in the early 19th century, either. There’s a reason they called those early, tire-less bicycles “Boneshakers”
A horse would be a helluva lot more comfortable. Or a carriage or cart with some sort of spring system (which they did have, as a matter of course).
Minor nit: “gears” that mate to roller chain are properly refered to as sprockets. (do you want to touch Dieter’s monkey?)
To the OP: I seem to recall a drawing of roller chain done by Leonardo da Vinci.
<googles>
My memory is good: from this Wikipedia article:
So, lacking roller chain, there were no “bicycle mechanisms” prior to 1880. Consider that the Wright brothers were running a bicycle shop around 1900, the idea apparently took hold very rapidly.
OK, but aside from driving two-wheeled vehicles, what is it ideal for? A lot of the things I mentioned earlier that require human motive power (looms, lathes, potter’s wheels) are still available in human-powered form today, but haven’t generally been adapted to use bicycle-style drives because the existing method of powering them is completely adequate.
It’s only good for some applications - of which bicycles are probably the key, so I think the bicycle-style drive was held up waiting for the invention of the bicycle.
A roller chain is not essential to the bicycle mechanism, though it makes it more efficient. Most of Industrial Revolution was powered by steam engines or water wheels that used leather belts and systems of pulleys to transmit power.
From an engineering standpoint, it is ideal for any machine that requires a compact, portable power source that can run on a variety of fuels. I suspect the reason was not technical, but social or economic. If foot treadle looms and potter’s wheels were adequate to fill demand, there was no economic need for larger looms that might require more power. The invention of agricultural machines such as the plow and the reaper only occurred when manual labor was no longer economical to fill the demand. Perhaps it is something like that.
I think it might be somewhat the case that bicycle cranks require the use of both legs, very often that the hands grip something like handlebars (even for a stationary machine) and cause the torso to rock quite a bit, whereas treadles can very often be operated with one leg and no hands - leaving the operator with both hands free to operate the machine (or throw the pot etc), and one leg free to steady him/herself against the floor, at the same time as being perfectly adeqate in terms of required power. if you needed more power, it was very often a lot more power, so you’d have a water mill, or a treadmill driven by humans or animals. For mobile power, there were horses and oxen
There are examples of roller chain from Roman times - on a rather larger scale than a bicycle, but undeniably roller chain. The example I’m thinking of is on this page - reconstruction of the whole mechanism has obviously been somewhat speculative, but they did find intact sections of articulated chain.
Also from later-period China (11th C.) - the water clock of Su Song used a chain drive, apparently based on a chain pump similar to, and roughly contemporaneous with, that Roman example.