US3899651A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for control of weld temperature in a high frequency electric resistance welded pipe mill
Assignee: United States Steel Corp
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Filing: 1973-10-11
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Granted: 1975-08-12
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Expires: 1993-10-11
Abstract
Abstract A system for control of the welding temperature in a high frequency electric resistance weld pipe mill utilizes wall thickness, speed and weld current as input parameters in a control circuit based on the thermal power necessary to heat the skelp to the desired temperature. The control circuit includes adjustments for changes in dynamic forging forces.
Inventors
- 👤 Howard J Bowman
- 👤 Donald G Schindler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:29
CPC Classifications
B; B23; B23K; B23K13/00; B23K13/04; B23K13/043; B23K13/046
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
42 words
A method of controlling the welding temperature in a high frequency electric resistance welded pipe mill comprising the steps of selecting a control factor, for which an actual value will be compared to a desired value for control purposes, from the equation
Claim 2
Independent Claim
42 words
A method of controlling the welding temperature in a high frequency electric resistance welded pipe mill comprising the steps of selecting a control factor, for which an actual value will be compared to a desired value for control purposes, from the equation
Claim 3
Dependent Claim
34 words
A method according to claim 1 in which the control factor is S, the remaining factor and its value is the desired value of KR/ Delta T and the mill control parameter is S.
Claim 4
Dependent Claim
33 words
A method according to claim 1 in which the control factor is Delta T/KR, the remaining factor and its value is the actual value of S and the mill control parameter is I.
Claim 5
Dependent Claim
53 words
A method according to claim 1 which includes the steps of measuring the static force exerted by the forging rolls, continuously measuring the dynamic force exerted by the forging rolls and continuously calculating and applying a correction to the weld power current for calculation purposes from said measurements of static and dynamic forces.
Claim 6
Dependent Claim
60 words
A methoD according to claim 1 in which the step of varying said mill control parameter includes the steps of continuously converting said difference signal to a zero center control signal for varying said mill control parameter, and continuously limiting the magnitude of said zero center control signal to a predetermined level above zero and a predetermined level below zero.
Claim 7
Dependent Claim
28 words
A method according to claim 1 which includes the step of providing a signal representative of a desired forging force for calculating said one value of said factor.
Claim 8
Dependent Claim
38 words
A method according to claim 6 which includes the steps of monitoring the value of the forging force and adjusting the forging force to a value within a desired range when the value is outside the desired range.
Claim 9
Dependent Claim
27 words
Apparatus for controlling the welding temperature in a high frequency electric resistance welded pipe mill comprising: means for calculating a desired mill speed according to the equation
Claim 10
Dependent Claim
27 words
Apparatus for controlling the welding temperature in a high frequency electric resistance welded pipe mill comprising: means for calculating a desired mill speed according to the equation
Claim 11
Dependent Claim
87 words
Apparatus according to claim 8 in which the means for providing a signal representative of the actual weld power current includes a conductor assembly connected to the weld power supply, a current sensor located in a slot along a face of said assembly, said sensor having a ceramic core, a winding of litz wire wrapped around said core and a protective glass tube surrounding said winding and said core and signal conditioning means connected to said winding for providing a current signal compatible with said calculating means.
Claim 12
Dependent Claim
44 words
Apparatus according to claim 8 in which said means for varying the speed of the mill drive motor includes means for limiting the variation in speed a predetermined amount below and a predetermined amount above a set mill speed in response to said comparison.
Claim 13
Dependent Claim
78 words
Apparatus according to claim 8 which includes means for measuring the static force exerted by the measuring rolls, means for measuring the dynamic force exerted by the forging rolls, means connected to said force measuring means for comparing the static and the dynamic forces and means connected to said means for comparing, said means for providing a current signal and said calculating means and responsive to said comparison for providing an adjusted current signal to said calculating means.
Claim 14
Dependent Claim
23 words
Apparatus for controlling the welding temperature in a high frequency electric resistance welded pipe mill comprising means for calculating according to the equation
Claim 15
Dependent Claim
23 words
Apparatus for controlling the welding temperature in a high frequency electric resistance welded pipe mill comprising means for calculating according to the equation
Claim 16
Dependent Claim
87 words
Apparatus according to claim 12 in which the means for providing a signal representative of the actual weld power current includes a conductor assembly connected to the weld power supply, a current sensor located in a slot along a face of said assembly, said sensor having a ceramic core, a winding of litz wire wrapped around said core and a protective glass tube surrounding said winding and said core and signal conditioning means connected to said winding for providing a current signal compatible with said calculating means.
Claim 17
Dependent Claim
45 words
Apparatus according to claim 12 in which said means for varying the weld power current includes means limiting the variation in weld power current a predetermined amount below a set weld power current level and a predetermined amount above a set weld power current level.
Claim 18
Dependent Claim
78 words
Apparatus according to claim 12 which includes means for measuring the static force exerted by the measuring rolls, means for measuring the dynamic force exerted by the forging rolls, means connected to said force measuring means for comparing the static and the dynamic forces and means connected to said means for comparing, said means for providing a current signal and said calculating means and responsive to said comparison for providing an adjusted current signal to said calculating means.
References Cited (Backward Citations)
US3548141A
Cited
US3573416A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-11 | 1979-02-10 | 1979-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-11 | 1983-02-10 | 1983-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-11 | 1987-02-10 | 1987-08-12 | $7700.00 | Window Closed / Lapsed |