(U.S.Pat. No. 3,481,223)
“It’s a marvelous device, simple and well made. All the parts fit. And it has won over our strong initial skepticism.”Cycle World Magazine, February, 1972
The Shifter Switch was a “speed goodie” for Motocross bikes.
It worked by coupling the ignition to the transmission, allowing clutchless shifting, while holding the throttle wide open.
Cycle World liked it. Here is their article: