Patent for a convertible biplane-monoplane, Byron T.Wall

[Jemiba]

Originally posted by hesham, I've moved the pictures and added the patent
drawing from http://www.freepatentsonline.com/2288501.pdf.

It would be interesting to know the aerodynamical efficiency of the lower wing, when in the
biplane configuration, as the recess for the upper wing was fully exposed to the slipstream.

 

[Orionblamblam]

That leading edge makes me unhappy.

 

[Stargazer]

How the very crude design in the official patent became a Boulton Paul turret fighter type in a magazine is truly typical of the way popular "Mecha" and "Science" magazines sometimes interpolated a design from a simple patent sketch to give it more flavor...

As to the leading edge... you have to remember that the airplane would have been in that configuration only on approach, at slow speed, and with the incidence typical of a landing, so the airflow on the lower wing's top would not have been so much of an issue I think.

 

[cluttonfred]

Not unlike some Soviet biplane prototypes like the Nikitin/Shevchenko IS-1, IS-2 and IS-4, except their lower wings folded into the upper ones. There was apparently an IS-3 as well but I don't have any more info. Here's the IS-2, more pics at the links above, all from the virtual Russian Aviation Museum site.

 

[Justo Miranda]

Hi

 

[Stargazer]

Not unlike some Soviet biplane prototypes like the Nikitin/Shevchenko IS-1, IS-2 and IS-4, except their lower wings folded into the upper ones.

If you look carefully at the Wall patent, you'll see that the last diagram shows an alternate configuration for a high-wing monoplane (possibly a flying boat) having the lower wing that retracts in a totally different manner. Not the same as the Nikitin/Shevchenko designs, but an indication that the patent covered the principle of monoplane-turning biplane-turning-monoplane-again rather than a specific design.

 

[cluttonfred]

True, thanks for pointing that out, Skyblazer. On the other hand, the Soviet IS-1 first flew in 1939 while the Wall patent was not filed until October 9, 1940 and not granted until June 30, 1942.