Bicycle Chain Catcher

This is my chain catcher design. The idea is that if the chain were to derail and fall towards the bottom bracket and seat tube, this chain catcher will try to force it back on the chainring. If not it should keep the chain from falling to the bottom bracket causing damage. Occasionally my chain will fall this way, this happens on both my touring and road bike. When I am in the big chain ring and low rear cog and shift to a smaller front chain ring the chain will fall off. Happens rarely but