US 5,263,307 AGranted

Corrosion resistant PC steel stranded cable and process of and apparatus for producing the same

AssigneeHokkai Koki Co., Ltd.

InventorTakeshi Hasui

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Abstract

A corrosion resistant PC steel stranded cable for a pretensioning method has a core wire and a plurality of side which are coated firmly for the corrosion proof with paint of a synthetic resin material while maintaining a stabilized stranded condition. The cable comprises the single core wire and the plurality of side wires disposed in a closely contacting relationship with each other and also with the core wire in such a manner as to define a plurality of spiral air gaps between the core wire and the side wires and also to define a plurality of spiral recessed grooves between individual adjacent ones of the side wires on the outer side of the side wires. Each of the core wire and the side wires are processed by blueing in advance. Paint of a synthetic resin material is filled in the spiral air gaps, and a coating layer of paint of a synthetic resin material is formed substantially with a uniform thickness on an entire outer periphery of the side wires including the spiral recessed grooves. A process of and an apparatus for producing such corrosion resistant PC steel stranded cable are also provided.

Claims9

Dependent claims

A process of producing a corrosion resistant PC steel stranded cable from a bare PC steel stranded cable comprising a core wire and a plurality of side wires disposed in a closely contacting relationship with each other and with the core wire to define a plurality of spiral air gaps extending the length of the cable between said core wire and said side wires, said cable being adapted to be introduced into concrete, the process comprising the steps of:

preprocessing each of said core wire and said side wires with blueing to maintain a stabilized condition of said cable such that said cable has a twist habit in which said side wires and said core wire are inclined to maintain a twisted condition thereof,
continuously untwisting the bare PC steel stranded cable over a predetermined length within a range within which the twist habit thereof is maintained,
heating said bare PC steel stranded cable to a degree required to melt a synthetic resin paint material to be applied thereto,
applying said synthetic resin paint material to the core wire and the side wires of an untwisted portion of the bare PC steel stranded cable to coat the core wire and the side wires individually with coatings of the synthetic resin paint material, and
subsequently twisting the side wires around the core wire of the untwisted portion of the bare PC steel stranded cable, wherein a plurality of outwardly directed spiral recessed grooves are formed between adjacent ones of stranded side wires on outer surfaces of said stranded side wires for introducing a predetermined prestress to said concrete, said grooves extending in a longitudinal direction of said PC steel stranded cable.

2 more elements

An apparatus for producing a corrosion resisting PC steel stranded cable adapted to be introduced into concrete, comprising:

a supplying device for supplying therefrom a bare PC steel stranded cable in a twisted condition which comprises a core wire and a plurality of side wires disposed in a closely contacting relationship with each other and with the core wire to define sprial air gaps extending the length of the cable therebetween, each of the core wire and the side wires being pre-processed by blueing to maintain a stabilized condition of said cable such that said cable has a twist habit in which said side wires and said core wire are inclined to maintain a twisted condition thereof;
an untwisting device for continuously untwisting the bare PC steel stranded cable supplied from said supplying device over a predetermined length within a range within which the twist habit thereof is maintained;
means for heating said bare PC steel stranded cable;
a first powder paint applying device for applying a synthetic resin paint material to the core wire and the side wires of the untwisted portion of the predetermined length of the bare PC steel stranded cable to coat the core wire and the side wires with the synthetic resin paint material to obtain a corrosion resisting PC steel stranded cable, said synthetic resin paint material being applied to said bare PC steel stranded cable after said bare PC steel stranded cable has been heated by said heating means to a degree required to melt said synthetic resin paint material applied to said bare PC steel stranded cable, wherein said corrosion resisting PC steel stranded cable has a plurality of outwardly directed spiral recessed grooves formed between adjacent ones of the side wires having been coated with said synthetic resin paint material, said grooves being for introducing a predetermined prestress to said concrete, said grooves extending in a longitudinal direction of said PC steel stranded cable, and the corrosion resisting PC steel stranded cable being automatically restored to the twisted condition of the bare PC steel stranded cable after being fed out from said first powder paint applying device;
and
a take-up device for winding thereon the corrosion resistant PC steel stranded cable having been restored to the twisted condition.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/908,883Filed 7 Jul 1992 · continuation
Priority: 15 Feb 1991
Granted: 23 Nov 1993
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

D07B 1/144
Comprising liquid, pasty or powder agents, e.g. lubricants or anti-corrosive oils or greases: for cables or cable components built-up from metal wires
D07B 7/185
For spreading or untwisting ropes or cables into constituent parts for treatment or splicing purposes: for temporarily untwisting ropes or cables…
D07B 2201/2012
Characterised by a coating: comprising polymers
D07B 2201/2044
Characterised by a coating: comprising polymers