This invention comprises improved means for controlling the inlet and exhaust of engines in which a single valve serves for the admission of fresh air into the cylinder and for the passage of the exhaust gases therefrom.
The distributing apparatus has the air-inlet passage connected with a supply of compressed-air so that the air is admitted under pressure into the cylinder , and also assists to expel the burnt gases, one and the same main valve serving for exhausting the burnt gases from the cylinder and for simultaneously admitting the air thereto.
The air passes to the main valve through a slide-valve attached to the main valve, the arrangement being such that the main valve opens before the slide-valve, whilst in closing, the slide-valve closes before the main valve.