Abstract: A system for monitoring the geometry of a mechanical structure comprising a plurality of interconnected rigid elements by means of an optical skeleton (A, B, C) constituted by a light beam (24) running along the elements (10, 12, 14) of the structure, together with photodetector means (28, 32, 36, 40, 42, 46) which are associated with the elements of the structure and towards which fractions of the light beam (24) are directed. The invention is applicable to moving structures such as robots or manipulator arms, as well as to fixed structures.

Abstract: Method and device for displacing the laser beam on a part by means of a reflexion mirror (20) and focussing lenses (24, 26). A small amplitude motion of the mirror (20) with respect to perpendicular rotational axes crosses at its center is superposed to the motion of the part with respect to the mirror (20) - lenses (24, 26) assembly. The invention applies particularly to the control of the displacement of laser beams used for cutting, marking, and welding parts.

Abstract: A carburetor for an internal combustion engine has a circuit for delivering a primary air/fuel mixture into the induction passage and means for correcting the richness of the airfuel mixture in dependence of the amplitude of the alternating component of the depression which prevails in operation in the induction passage. The correction device has a movable member which meters an air or fuel flow cross-sectional area in the circuit. The position of the movable member is controlled in dependence of the alternating component by a pressure sensitive diaphragm. A frequency filter connects the induction passage and chambers separated by the diaphragm for dampening the alternating component of the depression by an amount which increases with the frequency of that component.