Method of reshaping tubular conductor sheath

#The present invention relates to a clamping device for securing HF fittings to coaxial cables or hollow conductors by means of a clamping sleeve surrounding the cable outer sheath or the hollow conductor sheath.

#Such clamping devices are made to match the nominal size of the sheath so that a mechanical securing and end-face contacting is effected at the flanged end of the sheath. The end-face contacting is produced by axial tensioning of the flanged end whilst the mechanical securing is generally effected independently thereof via a radially acting clamping device which exerts a radial pressure on the sheath. The connection of plug or connector fittings by means of such clamping devices is however frequently very problematical because the dimensions of the fitting can be made with great accuracy whereas the dimensions of the sheath of coaxial cables or hollow conductors are often very different from the nominal size. Since hitherto the clamping sleeve was always dimensioned to match the nominal size of the sheath, with tolerance deviations of the sheath diameter upwardly difficulties are encountered on fitting the clamping sleeve whereas when the cable diameter is smaller than the nominal size the mechanical securing is no longer adequate and an inaccurate and loose attachment inevitable. Furthermore, in the entire tolerance range a reflection point is produced because the compensation of the transition piece is designed for the upper tolerance outer dimension of the cable. Particular difficulties are encountered with securing to oval or elliptical corrugated sheaths.

#The problem underlying the invention is to construct the clamping device in such a manner that excellent and reliable securing to all sheaths whose diameter is within the relatively large tolerance range is possible and no reflection point is formed.

#Some examples of embodiment of the invention will be explained hereinafter with reference to the drawings, wherein:

#FIG. 1 is a sectional view of a conical clamping sleeve fitted to a corrugated sheath,

#FIG. 2 is a sectional view corresponding to FIG. 1 of a clamping sleeve with cylindrical end portion,

#The examples of embodiment illustrated in the drawings show diagrammatically the fixing of various clamping sleeves on a corrugated sheath 10. This may the outer sheath of a coaxial cable or a hollow conductor. The sheath may be circular, elliptical or oval. The application of the invention is not restricted to clamping devices for corrugated sheaths but can also be used for smooth sheaths. However, the invention is particularly important in conjunction with corrugated sheaths because in the latter the tolerance deviations are particularly high.

#In the embodiment of FIG. 1 the clamping sleeve 12 is provided with a conical inner thread which in the front end portion where the end 14 of the sheath 10 is flanged has a diameter corresponding to the lowermost tolerance dimension whereas the opposite end has a diameter corresponding to the uppermost tolerance dimension. The diameter d.sub.1 represents the lowermost tolerance dimension of the cable outer diameter, the diameter d.sub.n the nominal outer diameter and the diameter d.sub.2 the outer diameter having the uppermost tolerance dimension. This conical arrangement guarantees that the sheath is compressed down to the smallest tolerance dimension (if it is not already this size due to its own minus tolerance).

#It is thus always guaranteed that the sheath has a predetermined dimensioning at the point of entry into the fitting.