Method for the manufacture of wires stretched according to a predetermined profile

A method for the controlled stretching of one or more optic fibers comprising the following steps:

• dictating a speed V.sub.e =dx.sub.e /dt of flow of the fiber entering the heating chamber,
• choosing a relationship f of variation of the diameter D.sub.s of the fiber such that D.sub.s =f(x.sub.s) in which x.sub.s represents the positions, variable in time, of a point on the fiber during exit from the heating chamber,
• carrying out successive stretching operations on the fiber to modify, during each said stretching operation, the diameter D.sub.s of the fiber during exit from the heating chamber so as to follow the profile defined by the relationship f of variation, wherein, to perform the successive stretching operations on the fiber so as to modify, during each said stretching operation, the diameter D.sub.s of the fiber and follow the profile defined by the relationship f of variation,
• a first value of the diameter D.sub.s of the fiber during exit from the heating chamber is determined, on the basis of the relationship f, as a function of the position x.sub.s of the point on the fiber during exit from the heating chamber,
• a shift dx.sub.s in position x.sub.s of the point on the fiber is determined to obtain a stretching of the fiber during exit from the heating chamber corresponding to the first value, on the basis of the value of the speed dx.sub.s of flow of the fiber at entry into the heating chamber and of the previously computed value of the diameter D.sub.s,
• a new position x.sub.s of the point on the fiber during exit from the heating chamber is determined by increasing the value of the previously computed shift dx.sub.s,
• the operations up to the obtaining of the desired profile are reiterated.