US3640776A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coated wire for use in prestressed concrete structures and method of producing same
Assignee: Wire Rope Corp of America Inc
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Filing: 1969-09-10
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Granted: 1972-02-08
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Expires: 1989-09-10
Abstract
Abstract Wire for prestressed concrete structures. The wire is initially produced by cold reduction from a high-carbon material whereby to produce a high-strength wire having a tensile strength of about 250 K s.i. (1,725MN/m.2). The surface of such wire may have a drawing compound embedded in it. This wire is first coated with a chromic acid, phosphoric acid solution which is then dried on the wire. A very thin organic coating, such as an organic phosphate, is then applied to the wire having the chromic acid, phosphoric acid coating dried thereon. The wire, now having the organic coating applied thereto, is then cured.
Inventors
- 👤 Eugene E Haney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:32
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/82; C23C22/83; C23C22/05; C23C22/06; C23C22/24; C23C22/33; E; E04; E04C; E04C5/00; E04C5/01; E04C5/015; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/261; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/294; Y10T428/2942; Y10T428/2958
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
97 words
A wire for prestressed concrete structures comprising a thinly coated steel wire having a high tensile strength, said coating being the end reaction product of P2O5 and water in which the P2O5 is present in at least the range of 2.0 to 10.0 percent, CrO3 and water in which the CrO3 is present in at least the range of 0.5 to 2.0 percent, and an organic compound wettable with and bondable to concrete and compatible with and reducing to the CrO3 whereby to form CrO2, said coating being very thin, on the order of 1 molecule thick.
Claim 2
Independent Claim
138 words
A method of making wire for prestressed concrete structures which comprises providing a steel wire having a high tensile strength, passing said steel wire briefly through aqueous solutions of phosphoric acid in which the phosphoric acid is present in the range of at least 2.0 to 10.0 percent and chromic acid in which the chromic acid is present in the range of at least 0.5 to 2.0 percent, promptly drying said steel wire, passing said steel wire through an organic compound wettable with and bondable to concrete and reducing to and compatible with chromic acid (CrO3), drying said organic compound, and heating said steel wire to effect a reaction between said chromic acid on said wire and said organic compound, whereby to achieve a final coating on said wire which is on the order of 1 molecule thick.
Claim 3
Dependent Claim
14 words
The method of claim 3 including the step of stress relieving the steel wire.
Claim 4
Dependent Claim
125 words
A wire for prestressed concrete structures, said wire having an undercoating thereon comprised of the reaction products of an aqueous phosphoric acid, chromic acid solution applied thereto, said phosphoric acid solution having phosphoric acid in the range of at least 2.0 to 10.0 percent and said chromic acid solution having chromic acid in the range of at least 0.5 to 2.0 percent, and a very thin outercoating on said undercoating, said outer coating resulting from the application of a thin layer of a liquid organic coating wettable with and bondable to concrete and compatible and reactive with the chromic acid on the wire, whereby said wire is resistant to corrosion and to stress corrosion cracking and whereby said wire bonds to concrete with high efficiency.
Claim 5
Dependent Claim
38 words
The wire of claim 5 in which the total thickness of the under and outer coatings is very thin, said outer coating being on the order of 1 molecular thickness, whereby to prevent shear failure within the coatings.
Claim 6
Independent Claim
126 words
A method of producing a wire for pretensioned and posttensioned concrete, which wire is resistant to corrosion and to stress corrosion cracking and which wire has a highly efficient bond to concrete, comprising the steps of applying an aqueous solution of phosphoric acid, chromic acid to the wire, said phosphoric acid solution having phosphoric acid in the range of at least 2.0 to 10.0 percent and said chromic acid solution having chromic acid in the range of at least 0.5 to 2.0 percent, drying the solution on the wire, applying a thin organic coating to the dry acid-coated wire, said organic coating being wettable with and bondable to concrete and compatible and reactive with chromic acid, and curing the thus-coated wire to dry said organic coating.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |