Consider a ratchet wrench --or, rather, the ratchet mechanism that give it its name. When the handle is oscillated, the ratchet turns an axle in just one direction.

Suppose that handle was a vane with significant surface area. If placed in an airstream such as the wind, the typical vane simply indicates wind-direction. That's because the vane is usually oriented horizontally. But if it was mounted vertically, with an axle along the long edge of the vane, it might flap in the wind. So....

Let's start with a 1-meter-long vertical axle. We place ratchets at the top and bottom of the axle, and a vane fits between them, extending from the axle for only 5 centimeters or so (it is not quite 1 meter tall). If the vane flaps in the wind, the axle is forced to rotate in only one direction. An extension of the axle could be the shaft of a generator.

As a bonus, because we are talking about two ratchets, one of them could be connected with a reversing gear to the axle. That way, whichever way the vane flaps, it applies rotational force to the axle, always in the same direction.

We now note that our nearly-1-meter-tall vane has two long edges. There is an axle along one edge, and now we want to put another axle along the other edge. Since the axle is 1 meter long, and the vane is a little shorter than that, part of the axle extends above and below the vane. We mount "ratcheted sprockets" on the axle at those locations, on BOTH axles. We connect them with standard drive-chains, like a bicycle has.

Next, we add another vane. Think of that second axle as being like a hinge-pin, and the two flat portions of a typical hinge are the vanes. So, starting at the generator-axle, it is connected by a ratchet mechanism to the first vane, and that is connected to another vane with a hinge-pin axle. However, this vane can flap independently of the first vane, and when it flaps, it drives the ratcheted sprockets, which move the chain and help drive the first axle.

We can now add another axle to the second long edge of the second vane, with more ratcheted sprockets, and a third vane. The second axle will actually have 4 sprockets on it, 2 above the vane and 2 below it. Of each pair, one sprocket connects with a chain to the first axle, and the other connects with a chain to the third axle. All three vanes can now flap independently of each other, and all contribute to sending mechanical force to the generator axle, thanks to the ratchets.

We can now extend the preceding with several more axles and vanes. At 5 centimeters per vane, if we had 30 of them the total extension from the first axle would be about 1 and 1/2 meters. The overall device has roughly the proportions of the average national flag. We can now paint it to look like an ordinary cloth flag. It flaps in the wind like a cloth flag, too**. And it generates power whenever it flaps. It might even flap in light breezes, because it doesn't sag like a cloth flag.

**Well, actually, the more mass is associated with this device, the less it will flap. Perhaps the vanes need to be frameworks with sailcloth stretched across the space inside the frames. And that 1-meter-by-1.5-meter description could be greatly enlarged, so the "flag" is huge, but interacts with as much wind as possible.
-- Vernon, Mar 28 2015

Both ways ratchet Both_20ways_20ratchet
It appears I'm not the only one who could use such a device, although the description in the main text here talks about two ordinary ratchets, one of them associated with a reversing gear. One-OR-the-other ratchet goes click-click-click when the vane flaps, while the one that isn't clicking uselessly is applying force to the generator axle, always in the same direction. All the other ratchet-driven axles can have that feature, too. [Vernon, Mar 28 2015]

Both ways screwdriver http://toolguyd.com...river-video-review/
Double-ratcheting tech does exist and does work [Vernon, Jan 07 2017]

Windbelt https://en.wikipedia.org/wiki/Windbelt
Prior art. Basically this, but anchored at both ends. [notexactly, Jan 09 2017]

Normally, when you're trying to capture wind energy, you set up a windmill, which, so to speak, tries to stay pointed towards the wind.

It looks as though you're trying to capture wind energy from a weather-vane, which, so to speak, tries to stay as far as possible out of the wind.

A windmill says to the wind, "Oi, in your face; where do you think you're going with that energy? I'll have that, thank you very much!". A weather vane says, "Oops, sorry, am I in your way? Don't mind me - I'll just go over here, and then you can get past".

This idea is like a weather vane with an attitude problem, that occasionally tries to trip up the wind or pick its pocket in passing, but has very limited ambitions. Or have I misunderstood it?
-- pertinax, Mar 29 2015


[pertinax], it takes energy to cause a flag to flap in the wind. This Idea is about capturing that flapping-energy. Yes, I know it can't be a lot, and I know the device is probably excessively complex, but I also know this is the HalfBakery....
-- Vernon, Mar 29 2015


A note on adding a reversing gear to a ratchet-driven axle: Here is an ASCII sketch (axle is horizontal and has 2 segments):
====DVC====
The "D" "V" and "C" are all bevel gears (the axle of the "V" gear, not shown, is perpendicular to the other axle). The two segments of the overall/shown axle will rotate in opposite directions.

Therefore one of the two axle-segments can be ratchet- driven by a particular oscillation-direction, and the other axle-segment can be ratchet-driven by the opposite oscillation-direction. A generator attached to either axle will always receive force from either oscillation-direction.
-- Vernon, Mar 29 2015


// This idea is like a weather vane with an attitude problem //

[marked-for-tagline]
-- notexactly, Mar 29 2015


Could be done with water in pipes, non-return valves and so on.

Wind send ripples down the flag, which compress part of the pipe, so pumping water about.

Or magnetically - flag has lots of rods 90 degrees to the surface of the flag, the rods have magnets on them, which sit in coils etc would work best with segmented flag.
-- not_morrison_rm, Jan 08 2017



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