Abstract: Method and device of servo-controlling a rotating workpiece in relation to a member such a tool capable of translational motion along a system of two mutually perpendicular axes as a function of a desired rate of transit of the periphery of said workpiece past said tool, in which a tangent to said periphery is determined and the tool is slaved to the displacement of said tangent parallel to itself, while the angular position of said workpiece is determined and the speed of the tool is varied along its system of axes as a function of said displacement of the tangent. Application to the automatic welding of odd pieces.

Abstract: The line-trace to be read-out is illuminated by a light spot scanning radially from, and by rotation around, a center that it set near the line-trace to be read, the radial scan having its own scan frequency and the scan turning around the center at a specific frequency of rotation. A signal is formed corresponding to the contrast modulation between the line-trace and the surrounding background, which is processed to give a signal corresponding to the minimum distance between the scan sweep center and the line-trace, the latter signal being processed further to produce the co-ordinates needed for directing the servo-control means of a machine tool.

Abstract: Method and device for servo-controlling the distance of an object from a transiting surface to be followed by said object and capable of reflecting microwaves, by exploiting a control signal, wherein a radiating unit fast with said object provides directive microwave radiation and a symmetrical detector compares the phases of the radiated microwaves and the reflected microwaves, said detector providing a control signal to a servo-control circuit. The device is namely intended to automatic metal-welding machines in which the welding member forms said object and a metal workpiece forms the reflecting surface to be followed at a predetermined distance by said welding member.

Abstract: A passenger-carrying conveyor-elevator has a helical track formed by a pair of spaced apart rails in which rollers of a succession of platforms ride. The platforms are of trapezoidal configuration with sides extending along radii of the helix and are connected together at their undersides by a flexible belt which is toothed to engage cog wheels of respective motor units driving the system.