Grumman (General Motors) FM-1 Wildcat (3)
When in 1932 Grumman built its first fighter for the Navy, the FF-1, it introduced a novelty: a retractable undercarriage. Several years later the same design was applied to the F4F. It in turn introduced a new novelty. Because space aboard aircraft carriers was at a premium, the Navy requested that Grumman develop a wing-folding mechanism. Grumman came up with an ingenious solution that involved hinging the wings such that they folded to lie parallel to the aircraft's fuselage -a system they labelled the 'Sto Wing'. Obviously the mechanism on my model works.
The same mechanism is still used today on the Northrop-Grumman E-2C Hawkeye.