Abstract: A casing has a circular cylindrical internal surface delimiting an operating chamber. An orbiting piston is mounted so as to orbit about a chamber axis which is the axis of the internal surface. The orbiting piston has a circular cylindrical external surface, a generatrix of the external surface being adjacent to the said internal surface, and a diametrically opposite generatrix spaced form the internal surface. A vane member has a tip face which faces the external surface of the orbiting piston and which has a length substantially equal to that of the orbiting piston. A linkage connects the vane member to the orbiting piston to keep the tip face adjacent the external surface. At least one of the external and internal surfaces has individual compliant strips distributed around the one surface, which run parallel to one another, and project above the one surface.

Abstract: A data processor comprises a multifrequency receiver formed together with a central processor on a semiconductor substrate. The multifrequency receiver produces digital data for identifying a tone wave included in a multifrequency analog signal or produces an identification result in accordance with the condition of signal issued by the central processor. The multifrequency receiver is thereby operative to deal with tone waves which are flexible in type and input analog signals which are flexible in their frequency band, and has increased latitude of choice for the operational characteristics and function such as the number of sampling periods of input analog signals and the discrimination accuracy.