Corliss, and later, poppet valve gears had separate admission and exhaust valves driven by trip mechanisms or cams profiled so as to give ideal events; most of these gears never succeeded outside of the stationary marketplace due to various other issues including leakage and more delicate mechanisms.
Along with poppet valve gears, what type of gears utilized separate admission and exhaust valves to give ideal events?
Corliss