Process and apparatus for the production of corrosion protection for cables made of parallel wire strands

Apparatus for producing a tension member comprising a bundle of parallel wire strands protected from corrosion and for use in cable stayed bridges comprising:

• (a) means for spreading the wire strands apart without disassembly of the bundle;
• (b) means, spaced from said spreading means, for reforming the wire strands into the bundle;
• (c) an injection housing positioned between said spreading and reforming means and defining a chamber including a longitudinal passage therethrough;
• (d) means for conveying the wire bundle through said longitudinal passage and through said spreading and reforming means to spread the wire strands of the bundle apart without disassembling the bundle and reforming the strands in a parallel wire bundle by collecting them together at the reforming means;
• (e) means including an injection nozzle in said chamber for injecting from within the spread strands a tacky synthetic resinous material with an anti-corrosion ingredient to coat all the strands while they are converging towards the reforming means, the resinous material being contained by the injection housing during injection and being sufficient in quantity to completely fill the interstices between the strands after conveying through the reforming means;
• and
• (f) means, located subsequent to said reforming means, for applying a close-fitting sheet metal casing to the composite reformed wire bundle and resinous material while the latter is still in tacky condition to thereby enclose same and to bond the casing to the wire bundle, wherein the quantity of the resinous material is sufficient to substantially fill the area between the wire strands and the casing, and the metal casing being longitudinally rigid to the extent that the encased wire bundle cannot be bent beyond a predetermined large radius or curvature without deforming the metal casing.

A process for producing a parallel wire tension member protected from corrosion and for use in cable stayed bridges comprising the steps of:

• (a) supplying a prefabricated parallel wire bundle from a supply source;
• (b) conveying the wire bundle through a spreader and reforming die means to spread the wire strands of the bundle apart without disassembling the bundle and reforming the strands in a parallel wire bundle by collecting them together at the reforming die;
• (c) injecting from within the spread strands a tacky synthetic resinous material with an anti-corrosion ingredient to coat all the strands while they are converging towards the reforming die, the resinous material being contained by an injection housing during injection and being sufficient in quantity to completely fill the interstices between the strands after the reforming strip;
• (d) tightly winding wire under tension around the reformed and resin filled wire bundle, with the quantity of resinous material being sufficient to also seal the wound wire layer;
• and
• (e) applying a close-fitting sheet metal casing in the form of continuously helically wound sheet metal strips under tension about the composite reformed, wire-wound, resin-filled wire bundle while the resinous material is still in tacky condition to thereby enclose same and to bond the casing to the wire bundle, the quantity of the resinous material being sufficient to substantially fill the area between the wire strands and the casing, and the metal casing being longitudinally rigid to the extent that the encased wire bundle cannot be bent beyond a predetermined large radius of curvature without deforming the metal casing.