Maybe you could go visit one and take measurements and pictures. (There's a small one at a tourist attraction near my nevada place but I don't think I'll be able to get to it any time soon.)
I can describe roughly how they work. (Rough because I've learned a lot about what to look for since the last time I saw one up close.):
- I think the blades are conical and bent out of sheet metal.
- Shaft has either a crank or a gearbox that drives a crank, depending on model. (I believe the gearbox models are for deep wells, the stright crank for shallow ones.)
- Crank pulls a pipe or rod up and down.
- Rod drives the shaft of an ordinary hand pump, down in the middle of the . (I haven't seen it operating but I think the idea is that the handle also moves, providing a counterweight to the shaft down the well and a manual backup for calm days.)
- I think there's some bar-from-mill-slides-through-hole-with-crossbar-to-keep-it-from-pulling-out-upward type mechanism just above the pump, so when the mill stops due to lack of wind you can work the handle without wasting manual power spinning the blades.
- Furls by swinging the tail sideways until it's parallel with the blade. I think the hinge axis is vertical and there's a spring return (rather than the tilted axis and tail weight designs typical here. You can force it to furl from the ground to stop the mill for maintainence or to conserve your well when you have enough water.
Proper term is "patent windmill" - implying there are historical patents with drawings and descriptions. (Some of the designs are so old, though, that it's more the original meaning of "patent" - a monopoly grant from the king for reasons not necessarily related to inventing a device.) That was a LONG time back so they probably won't be in any free internet patent databases. But you should be able to order them from the patent office or one of the patent search services.
Maybe somebody else can come up with some good pix or drawings with details and dimensions.