Shear Pins for Propellors?

wrote:

The shear pin would fail at idle.

How about this one. The prop would have a clutch plate on the front with a hole
in the center of both prop and plate large enough to fit over the end of the
crank. The prop/clutch assembly would slip over the end of the shaft and another
clutch plate assembly would bolt onto the end of the shaft. The latter would
have pivoting weights to increase pressure on the clutch as rpm rises (much like
some older CS props have to adjust blade angles). When the engine is producing
little power (as it would during landing), the prop would only be loosely
connected to the engine. Add power, and the clutch engages more and more
completely, both from the pressure added by the weight mechanism and by the
thrust pushing the prop forward.

This system would also allow the prop to windmill without attempting to turn the
engine in cases of engine failure.

You'd have to thread the inside of the crankshaft end and perhaps have to
rethink the current method of driving CS props with engine oil, but I doubt that
the problems are unsolvable.

George Patterson
Whosoever bloweth not his own horn, the same shall remain unblown.