US3863328A
Expired / Lapsed
US
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Method of making a Composite steel tubing
Assignee: Copperweld Steel Co
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Filing: 1974-01-22
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Granted: 1975-02-04
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Expires: 1994-01-22
Abstract
Abstract The specification discloses a double wall steel tubing and a method of making it which results in the production of steel tubing having a size range and wall thickness heretofore available only in a seamless tubing and possessing a uniformity of wall thickness within heretofore unattained tolerance limits. An outer welded tube is first telescoped over an inner welded tube. The two tubing sections are then mechanically bonded together as by being drawn through a sizing die in a sink pass without a mandrel or by forcing a mandrel through the inner tubing section. The composite tubing is then drawn through a second sizing die over a mandrel to produce a heavy wall tubing, equivalent in strength characteristics to single wall tubing of the seamless type.
Inventors
- 👤 John J Arntz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:26
CPC Classifications
B; B21; B21C; B21C37/00; B21C37/06; B21C37/15; B21C37/154; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826; Y10T29/49908; Y10T29/49925; Y10T29/49927; Y10T29/49934; Y10T29/49938; Y10T29/4994
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
99 words
The method of making a composite steel tubing comprising the steps of: a. providing two sections of welded steel tubing of substantially equivalent wall thickness, one of which sections has an outer diameter less than the inner diameter of the other; b. telescoping said tubing sections and locking them together at one end; cold drawing said telescoped tubing sections through a die without a mandrel to compress the outer tubing section onto the inner tubing section thereby to produce a mechanical bond therebetween; and d. cold drawing the united tubing sections through a sizing die and over a Mandrel.
Claim 2
Independent Claim
99 words
The method of making a composite steel tubing comprising the steps of: a. providing two sections of welded steel tubing of substantially equivalent wall thickness, one of which sections has an outer diameter less than the inner diameter of the other; b. telescoping said tubing sections and locking them together at one end; cold drawing said telescoped tubing sections through a die without a mandrel to compress the outer tubing section onto the inner tubing section thereby to produce a mechanical bond therebetween; and d. cold drawing the united tubing sections through a sizing die and over a Mandrel.
Claim 3
Dependent Claim
28 words
The method of making a composite steel tubing according to claim 1, wherein the sum of the wall thicknesses of the two tubing sections provided exceeds 0.340 inch.
Claim 4
Dependent Claim
30 words
The method of making a composite steel tubing according to claim 1, wherein one of the tubing sections provided has its mating surface scored prior to telescoping the tubing sections.
Claim 5
Dependent Claim
30 words
The method of making a composite steel tubing according to claim 1, wherein the outer diameter surface of the inner tubing section is scored prior to telescoping the tubing sections.
Claim 6
Dependent Claim
30 words
The method of making a composite steel tubing according to claim 1, wherein the inner diameter surface of the outer tubing section is scored prior to telescoping the tubing sections.
Claim 7
Independent Claim
87 words
The method of making a composite steel tubing comprising the steps of: a. providing two sections of welded steel tubing of substantially equivalent wall thickness, one of which sections has an outer diameter less than the inner diameter of the other; b. telescoping said tubing sections and holding them together at one end; c. changing the diameter of one of said tubing sections so as to produce a mechanical bond therebetween; and d. cold drawing the united tubing sections through a sizing die and over a mandrel.
Claim 8
Independent Claim
87 words
The method of making a composite steel tubing comprising the steps of: a. providing two sections of welded steel tubing of substantially equivalent wall thickness, one of which sections has an outer diameter less than the inner diameter of the other; b. telescoping said tubing sections and holding them together at one end; c. changing the diameter of one of said tubing sections so as to produce a mechanical bond therebetween; and d. cold drawing the united tubing sections through a sizing die and over a mandrel.
Claim 9
Dependent Claim
50 words
The method of making a composite steel tubing according to claim 6, wherein the change in the diameter of one of said tubing sections is accomplished by cold drawing the telescoped tubing sections through a die without a mandrel to compress the outer tubing section onto the inner tubing section.
Claim 10
Dependent Claim
35 words
The method of making a composite steel tubing according to claim 6, wherein the change in the diameter of one of said tubing sections is accomplished by expanding the inner one of said tubing sections.
Claim 11
Dependent Claim
30 words
The method of making a composite steel tubing according to claim 6, wherein the expansion of the inner one of said tubing sections is accomplished by forcing a mandrel therethrough.
Claim 12
Dependent Claim
28 words
The method of making a composite steel tubing according to claim 6, wherein the sum of the wall thicknesses of the two tubing sections provided exceeds 0.340 inch.
Claim 13
Dependent Claim
30 words
The method of making a composite steel tubing according to claim 6, wherein one of the tubing sections provided has its mating surface scored prior to telescoping the tubing sections.
Claim 14
Dependent Claim
30 words
The method of making a composite steel tubing according to claim 6, wherein the outer diameter surface of the inner tubing section is scored prior to telescoping the tubing sections.
Claim 15
Dependent Claim
30 words
The method of making a composite steel tubing according to claim 6, wherein the inner diameter surface of the outer tubing section is scored prior to telescoping the tubing sections.
Claim 16
Independent Claim
87 words
The method of making a composite steel tubing comprising the steps of: a. Providing two sections of welded steel tubing of substantially equivalent wall thickness, one of which sections has an outer diameter less than the inner diameter of the other; b. telescoping said tubing sections and locking them together at one end; c. changing the diameter of one of said tubing sections so as to produce a mechanical bond therebetween; and d. cold drawing the united tubing sections through a sizing die and over a mandrel.
Claim 17
Independent Claim
87 words
The method of making a composite steel tubing comprising the steps of: a. Providing two sections of welded steel tubing of substantially equivalent wall thickness, one of which sections has an outer diameter less than the inner diameter of the other; b. telescoping said tubing sections and locking them together at one end; c. changing the diameter of one of said tubing sections so as to produce a mechanical bond therebetween; and d. cold drawing the united tubing sections through a sizing die and over a mandrel.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |