Ignition devices for internal combustion engines and engines including such devices

Claim 1

In a rotary piston internal combustion engine, an ignition device, comprising means sensitive to the position of the throttle valve and to the rotary speed of the engine and arranged so as to be able to cause ignition retard, according to whether the two following conditions are simultaneously fulfilled: the degree of opening of the throttle valve controlling the intake pipe of the engine is less than a predetermined limit PL, and the rotary speed of the engine is greater than a predetermined limit NL, said means comprising a first suction capsule adapted to control the relative ignition retard, said first suction capsule being connected to the intake pipe of the engine at a point which passes from downstream to upstream of the throttle valve when the latter, in opening, passes through a degree of opening PL, and a second suction capsule provided to act in opposite sense from said first suction capsule and to control, at partial load, when the degree of opening of the throttle valve is greater than PL and the absolute value of the suction in the intake pipe increases, a relative ignition advance, said second suction capsule being connected to the intake pipe at a point which passes from upstream to downstream of the throttle valve when the latter, in opening, passes through a degree of opening equal or greater than PL, means for effecting advance and retard of the ignition, said capsules including respective diaphragms, rigid connecting means coupling the diaphragm of each said capsule and the ignition advance and retard means, and alternatively operable resilient means for resisting the relative ignition retard or advance during a degree of movement of the ignition.