Abstract: An intake air temperature control device for mixture-compressing internal combustion engines having an inlet flapper proportioning the flows of cold and preheated raw air into a duct junction and into raw air mixing duct, the flapper-adjusting wax thermostat being arranged inside a thermostat chamber into which branch flows of cold and preheated raw air are admitted through two calibrated branch inlets. A narrow annular gap through which the combined branch flows must pass assures an integrated response of the thermostat to changing temperatures and air intake speeds. A lost-motion drive connection and a biasing member produce a full-load correction of the adjusted temperature. The flapper drive members may have valve edges which cooperate with the calibrated branch inlets to open and close the latter.

Abstract: A device for adjusting the intake air temperature of a carburetor-equipped internal combustion engine whose air intake system has a flapper valve in a duct junction admitting cold raw air and/or preheated raw air to the intake filter, depending on the raw air temperature, the flapper valve position being controlled by a pneumatic membrane actuator which receives negative pressure from the intake manifold, via a vacuum line with a thermostat-controlled relief valve responsive to the temperature of the air mixture. In the drive connection between the membrane actuator and the flapper is arranged a wax thermostat which increases or decreases the effective length of the connection in response to the ambient air temperature, thereby adding the thermostat displacements to the actuator displacements, the effective length of the drive connection being further adjustable by means of a threaded connection which is arranged between the membrane support body of the actuator and the wax thermostat.

Abstract: A filter dust ejector with a built-in check valve as part of the exhaust system of an internal combustion engine, the ejector consisting of an ejector housing with a suction connector for an air hose leading to the air intake filter, and inlet and outlet pipes forming an annular suction gap in a venturi-type exhaust flow profile, thereby creating a negative pressure in the ejector housing. The inner extremity of the suction connector is a valve seat for a pivotably supported flapper serving as a check valve which is closed, when a pressure condition in the ejector housing tends to create a reverse flow of exhaust gas through the suction connector to the air intake filter.