Cowl Gills – Any technical details?

Hi Eddie

Brilliant – you are indeed a Smart 🙂 , did you just Google ‘cowl sprocket’?

It is a very good compact design and explains why you can’t really see it in the photos. You can see the raised bumps on the big flaps that I guess keep them in place and allow them to hinge.

I’ll read the patent through as I an interested to see how they resolve the confict between the linear movement of the sprocket and the (albiet small) rotation of the ‘finger’ part.

Clearly there would be the need for a powerful chain drive as the mechanical advantage is with the wind on the flap tips.

Thanks All

James

Something like this?

http://www.google.com/patents?id=N7hpAAAAEBAJ&zoom=4&dq=cowl%20sprocket&pg=PA3#v=onepage&q&f=false

I note that the authors worked for Bristol!

Decidedly few photos of the gill bits! However here are two.

In one you can see that all that is left of the flaps are ‘fingers’ (the hinged supports?). It looks as if these would be flat loops of metal between which, and inside which, the much larger flap sections (the Gill Plates?) are fitted. So that as the thin fingers open up the larger flaps are opened too but are free to slide. This gives a sort of umbrella effect so that there are no gaps. The first pic shows this well as you can see the ‘unpainted’ parts of the big flaps.

In the first pic you can see what looks like a rod from each of the fingers going deeper into the engine or are they pins sticking through the ring?

Still can’t get any images for the mechanism however!

James

Thanks Smirky

That’s a start – lots of power and slow operation by the look of it!

Cheers
James

http://www.flightglobal.com/pdfarchive/view/1946/1946%20-%202270%20-%200221.html

judging by the number of gears this shouldn’t be a problem 😉