Abstract: The invention discloses an apparatus for adjusting or actuating an air throttle valve positioned in the intake manifold of an internal combustion engine which is supplied by air under pressure. The air throttle valve is held in a closed position by a spring when the engine is in the cold starting phase. Air is supplied to the engine through a by-pass valve when the air throttle valve is closed. The air throttle valve is opened against the force of the spring in response to a predetermined pressure or vacuum in the intake manifold at the end of the cold starting phase. The air throttle valve is held in an open position by an electro-magnetic structure which is effective when an ignition circuit of the vehicle is energized or by a detent structure which is effective when the engine or exhaust temperatures are at predetermined levels.

Abstract: An actuator for an air valve placed in the boost air duct of an IC engine and, more specially, of such an engine supercharged or boosted by a pressure wave supercharger, the air valve being in its closed position on starting up the IC engine from cold, at which time the engine takes in charge air by way of a breather valve, and at the end of the starting stage the valve in the boost air duct is moved into its open position and is kept open while the engine is running. After shutting down the engine, the valve in the intake pipe is automatically moved back into its closed position and the air valve is moved into its open position by the pressure of the air forced into the boost air duct and/or by vacuum against an air valve spring closing force.

Abstract: A positioning device for an air valve arranged in the charging air line of a diesel engine, particularly charged by means of a pressure wave-charging device. The air valve or flap is provided with a shutoff valve incorporated into the flow path between an impingement line branching-off from a pressure oil line of the diesel engine and an oil return flow line. The impingement line is connected with an impingement chamber for a positioning piston actuating the air valve or flap. The positioning piston is loaded by a continuously effective force and the shutoff valve is actuated, in order to impinge the positioning piston with oil, in the opening direction of the air valve or flap by a control piston loaded by the pressure in the air charging line against the force of a spring.