US3919872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods and apparatus for tube rolling
Assignee: Friedrich Kocks GmbH and Co
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Filing: 1974-09-17
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Granted: 1975-11-18
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Expires: 1994-09-17
Abstract
Abstract A method and apparatus are provided for reducing the amount of out of tolerance end thickness in rolled tubing by subjecting the entering end of the tube, at least in the penultimate pass of those passes which build up tension in the tube, to a maximum tractive force.
Inventors
- 👤 Werner Demny
- 👤 Hermann Moeltner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:51
CPC Classifications
B; B21; B21B; B21B17/00; B21B17/14
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
148 words
A method of rolling tubes under tension in a multi-pass stretch-reducing rolling mill, in which, during the entry of the leading end portion of the tube into and the exit of the trailing end portion of the tube from the region of those passes of the rolling mill which are at the entry end when viewed in the direction of rolling and which build up the tension subjecting the tube, at least in the respective penultimate pass of those passes which build up the tension, to a maximum tractive force, which is limited only by the transmission capacity of the frictional forces between the rollers and the tube and is created by causing the relevant peripheral speed of the rollers in such passes at each point of contact surface between the rollers and the tube to be greater than the speed of the tube passing through said rollers.
Claim 2
Independent Claim
148 words
A method of rolling tubes under tension in a multi-pass stretch-reducing rolling mill, in which, during the entry of the leading end portion of the tube into and the exit of the trailing end portion of the tube from the region of those passes of the rolling mill which are at the entry end when viewed in the direction of rolling and which build up the tension subjecting the tube, at least in the respective penultimate pass of those passes which build up the tension, to a maximum tractive force, which is limited only by the transmission capacity of the frictional forces between the rollers and the tube and is created by causing the relevant peripheral speed of the rollers in such passes at each point of contact surface between the rollers and the tube to be greater than the speed of the tube passing through said rollers.
Claim 3
Dependent Claim
35 words
A method as claimed in claim 1, wherein the mill has more than six passes and in which the region in which the tube tension is built up is encompassed by the first six passes.
Claim 4
Dependent Claim
156 words
A rolling mill having multiple passes, each pass including three-rollers for rolling tubes under tension, which mill is so adapted that the speeds of the rollers are pre-determined and are substantially maintained during rolling, in which in the region of those passes which are at the front when viewed in the direction of rolling and which serve to build up the tension, the roller speed of the first pass of the rolling mill is determined in accordance with a c value equal to or smaller than 0.35, which fixes the rolling radius of the rollers, and the roller speed of the pass following the last of the passes which serve to build up the tension is determined in accordance with a c value of 1.0 or over, said c value being determined from the formula R 178 .WD-C.D) where R represents rolling radius, D the outer diameter of the tube and WD the ideal roller diameter.
Claim 5
Dependent Claim
156 words
A rolling mill having multiple passes, each pass including three-rollers for rolling tubes under tension, which mill is so adapted that the speeds of the rollers are pre-determined and are substantially maintained during rolling, in which in the region of those passes which are at the front when viewed in the direction of rolling and which serve to build up the tension, the roller speed of the first pass of the rolling mill is determined in accordance with a c value equal to or smaller than 0.35, which fixes the rolling radius of the rollers, and the roller speed of the pass following the last of the passes which serve to build up the tension is determined in accordance with a c value of 1.0 or over, said c value being determined from the formula R 178 .WD-C.D) where R represents rolling radius, D the outer diameter of the tube and WD the ideal roller diameter.
Claim 6
Dependent Claim
38 words
A rolling mill as claimed in claim 3, in which the roller speed of the penultimate pass of those passes which serve to build up the tension is determined in accordance with a c value of approximately 0.5.
Claim 7
Dependent Claim
47 words
A rolling mill as claimed in claim 3, in which the roller speeds of the individual passes in the entry region of the rolling mill are selected in accordance with c values, which in every case are greater than the c values of the respective preceding passes.
Claim 8
Dependent Claim
47 words
A rolling mill as claimed in claim 4, in which the roller speeds of the individual passes in the entry region of the rolling mill are selected in accordance with c values, which in every case are greater than the c values of the respective preceding passes.
Claim 9
Dependent Claim
60 words
A rolling mill as claimed in claim 3, in which the roller speeds of the second pass up to the last pass of those passes which serve to build up the tension, are determined in accordance with c values which linearly increase from a value equal to or smaller than 0.35 to a value equal to or greater than 1.
Claim 10
Dependent Claim
58 words
A rolling mill as claimed in claim 3, in which the roller speeds of the second pass up to the last pass of those passes which serve to build up the tension, are determined in accordance with c values which linearly increase from a value in excess of 0.35 to a value equal to or greater than 1.
Claim 11
Dependent Claim
58 words
A rolling mill as claimed in claim 5, in which the roller speeds of the second pass up to the last pass of those passes which serve to build up the tension, are determined in accordance with c values which linearly increase from a value in excess of 0.35 to a value equal to or greater than 1.
Claim 12
Dependent Claim
29 words
A rolling mill as claimed in claim 3, in which the region of those passes which serve to build up the tension is encompassed by the first six passes.
References Cited (Backward Citations)
US3552170A
Cited
US3645121A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |