US3707658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stretch control system for elongate material
Assignee: Westinghouse Electric Corp
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Filing: 1971-03-03
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Granted: 1972-12-26
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Expires: 1991-03-03
Abstract
Abstract System for controlling the speeds of rolls or the like in succeeding tandem stands of a rolling mill, or the speed of the rolls of a single stand operative with a take-up or pay-off reel, to produce a predetermined amount of stretch in elongate material passing through the mill. This is accomplished by generating alternating current signals whose frequencies are proportional to the speeds of succeeding stands in a tandem mill, for example, and by utilizing these signals to generate a direct current signal proportional to the difference in respective frequencies, and, hence, the difference in speeds. The value of this latter signal is then compared with a reference value to vary the speed of the second stand or a reel to maintain a substantially constant stretch relationship for the material.
Inventors
- 👤 Laurence L Hilsenbeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:53
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/16; B; B21; B21B; B21B37/00; B21B37/48; B21B37/52
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
199 words
In combination, first and second spaced rotary means between which elongate material passes such that the stretch produced in the material between said first and second rotary means will be dependent upon the respective angular speeds of the rotary means, means for producing a first electrical signal proportional to the angular velocity of said first rotary means, means for producing a second electrical signal proportional to the angular velocity of said second rotary means, means responsive to said first and second signals for producing a third electrical signal which varies as a function of the difference in angular velocities of the first and second rotary means and therefore varies as a function of the stretch in the material between the rotary means, means for producing a fourth electrical signal which is proportional to the desired stretch produced in the material between the first and second rotary means, means for comparing said third and fourth electrical signals to produce an error signal, and means responsive to said error signal for varying the speed of at least one of said rotary means until said third and fourth electrical signals are substantially equal and said error signal is substantially equal to zero.
Claim 2
Dependent Claim
199 words
In combination, first and second spaced rotary means between which elongate material passes such that the stretch produced in the material between said first and second rotary means will be dependent upon the respective angular speeds of the rotary means, means for producing a first electrical signal proportional to the angular velocity of said first rotary means, means for producing a second electrical signal proportional to the angular velocity of said second rotary means, means responsive to said first and second signals for producing a third electrical signal which varies as a function of the difference in angular velocities of the first and second rotary means and therefore varies as a function of the stretch in the material between the rotary means, means for producing a fourth electrical signal which is proportional to the desired stretch produced in the material between the first and second rotary means, means for comparing said third and fourth electrical signals to produce an error signal, and means responsive to said error signal for varying the speed of at least one of said rotary means until said third and fourth electrical signals are substantially equal and said error signal is substantially equal to zero.
Claim 3
Dependent Claim
27 words
The combination of claim 1 wherein the speed of the second one of said rotary means in the path oF travel of said elongate material is varied.
Claim 4
Dependent Claim
19 words
The combination of claim 1 wherein said spaced rotary means comprise spaced rolls through which said elongate material passes.
Claim 5
Dependent Claim
29 words
The combination of claim 3 wherein said elongate material comprises metal strip material and said spaced rolls comprise the work rolls of succeeding stands of a tandem rolling mill.
Claim 6
Dependent Claim
17 words
The combination of claim 1 wherein said means for producing a third electrical signal includes a modulator.
Claim 7
Dependent Claim
70 words
The combination of claim 1 wherein said first and second signals are alternating current signals and including first and second alternating current generators for producing the respective first and second alternating current signals, means for modulating said first alternating current signal with said second alternating current signal, and a filter connected to the output of said modulating means, with said third electrical signal appearing at the output of said filter.
Claim 8
Dependent Claim
81 words
The combination of claim 6 wherein said modulating means produces a first frequency component equal in frequency to one of said alternating current signals, a second frequency component equal in frequency to the difference in frequencies of said first and second alternating current signals, and a third frequency component equal in frequency to the sum of the frequencies of said first and second alternating current signals, said filter passing said second frequency component while rejecting said first and third frequency components.
Claim 9
Dependent Claim
29 words
The combination of claim 7 including means for varying the magnitude of said third electrical signal as a function of the angular velocity of one of said rotary means.
Claim 10
Dependent Claim
35 words
The combination of claim 8 wherein said third electrical signal is varied as a function of the angular velocity of the first of said rotary means in the path of travel of said elongate material.
References Cited (Backward Citations)
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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) | 1975-12-26 | 1976-06-26 | 1976-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-26 | 1980-06-26 | 1980-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-26 | 1984-06-26 | 1984-12-26 | $7700.00 | Window Closed / Lapsed |