Abstract: A pneumatically actuated adjusting device, particularly for throttle flap adjustment on mixture-compressing combustion engines, with a diaphragm held between a housing upper portion and a housing lower portion. This diaphragm forms a vacuum-charged working chamber with the housing upper portion. With the housing lower portion it forms a chamber open to ambient atmosphere. A guide bushing projects from the housing upper portion on the atmosphere vented side of the diaphragm and is rigidly connected to it. The diaphragm is also rigidly connected to two concentric spaced diaphragm plate pairs. The outer diaphragm plate pair is connected to a pipe moving inside the guide bushing. This pipe has one or several recesses, with a ball in every recess. Indentations in the guide bushing have diameters corresponding to the ball diameter, with the depth determining the stroke of the first adjustment stage. The inner diaphragm is rigidly connected to a control piston inside the pipe. This control piston has a recess.

Abstract: A control arrangement for effecting the reconveyance of exhaust gas over a larger engine operating range, while concurrently constructing the control to be more sensitive and better correlated with any particular thermal and/or mechanical operating condition of the internal combustion engine. The arrangement includes a multiple-position valve located in the conducting path of the control conduit, which is so located and constructed whereby the control pressure chamber of the control pressure chambers of the adjusting device are selectively subjected to a gas pressure and/or atmospheric pressure present in the intake conduit of the internal combustion engine upstream and/or downstream of the dosing arrangement for the combustion air or, respectively, the provided fuel-air mixture, or in the path of an accumulator associated with the control conduit.