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US4415976A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for automatic mill zero correction for strip width

Assignee: General Electric Co
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Filing: 1981-04-28
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Granted: 1983-11-15
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Expires: 2001-04-28
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Abstract

Abstract The change in the mill modulus of the stand of a rolling mill due to the particular strip width of a run strip of material is taken into account by reference to the unloaded mill modulus of the stand and a desired roll gap opening is calculated on the basis of an error relative to the actual roll gap opening in order to achieve a desired strip thickness setting.

Inventors

  • 👤 John W. Cook

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 04:02
CPC Classifications
B; B21; B21B; B21B37/00; B21B37/16; B21B37/165; B21B2261/00; B21B2261/02; B21B2261/06

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 163 words
A method of presetting the roll stands of a rolling mill comprising the steps of: closing the roll gap of a roll stand until a desired roll force RF is developed between the rolls; determining the actual mill stretch RF/M 1 of the empty mill modulus for said desired roll force at said stand; determining for said desired roll force the actual mill stretch RF/M 2 of the mill modulus at said stand if loaded with a strip of material of a given width; calculating the quantity ΔS=(RF/M 1 -RF/M 2 ); determining for a desired strip thickness DT a desired roll gap opening H 1 by the relation H 1 =DT-(S 1 -S 0 ), where S 0 is the separation of the rolls when the mill is empty and S 1 is the separation of the rolls when the mill is loaded; and opening the roll gap of said stand by an amount sufficient to reach said desired roll gap opening.
Claim 2
Independent Claim 163 words
A method of presetting the roll stands of a rolling mill comprising the steps of: closing the roll gap of a roll stand until a desired roll force RF is developed between the rolls; determining the actual mill stretch RF/M 1 of the empty mill modulus for said desired roll force at said stand; determining for said desired roll force the actual mill stretch RF/M 2 of the mill modulus at said stand if loaded with a strip of material of a given width; calculating the quantity ΔS=(RF/M 1 -RF/M 2 ); determining for a desired strip thickness DT a desired roll gap opening H 1 by the relation H 1 =DT-(S 1 -S 0 ), where S 0 is the separation of the rolls when the mill is empty and S 1 is the separation of the rolls when the mill is loaded; and opening the roll gap of said stand by an amount sufficient to reach said desired roll gap opening.
Claim 3
Dependent Claim 25 words
The method of claim 1 with said actual mill stretch of the loaded mill modulus determining step being effected in relation to the strip width.
Claim 4
Dependent Claim 32 words
The method of claim 2 with said actual mill stretch of the loaded mill modulus determining step being further effected in relation to the diameter of the back-up rolls at said stand.
Claim 5
Dependent Claim 64 words
The method of claim 2 or 3 wth the provision of a display of the actual roll gap opening and a display of the desired roll gap opening as determined by said desired roll gap opening determining step, said roll gap opening step being performed by matching the display of the actual roll gap opening with the display of the desired roll gap opening.
Claim 6
Dependent Claim 145 words
Apparatus for inwardly presetting the roll stand so of a rolling mill comprising: means for closing the roll gap of a roll stand until a desired roll force RF is developed between the rolls; first means for deriving the actual mill stretch RF/M 1 of the empty mill modulus for said desired roll force; second means for deriving the actual mill stretch RF/M 2 of the mill when loaded with strip material in relation to the loaded mill modulus at said stand for said desired roll force means for calculating the quantity (RF/M 1 -RF/M 2 ); third means for estimating a desired roll gap opening H 1 from the amount of a desired strip thickness ΔT less (RF/M 1 -Rf/M 2 ); and means for opening the roll gap of said stand by an amount sufficient to reach said estimated desired roll gap opening.
Claim 7
Dependent Claim 145 words
Apparatus for inwardly presetting the roll stand so of a rolling mill comprising: means for closing the roll gap of a roll stand until a desired roll force RF is developed between the rolls; first means for deriving the actual mill stretch RF/M 1 of the empty mill modulus for said desired roll force; second means for deriving the actual mill stretch RF/M 2 of the mill when loaded with strip material in relation to the loaded mill modulus at said stand for said desired roll force means for calculating the quantity (RF/M 1 -RF/M 2 ); third means for estimating a desired roll gap opening H 1 from the amount of a desired strip thickness ΔT less (RF/M 1 -Rf/M 2 ); and means for opening the roll gap of said stand by an amount sufficient to reach said estimated desired roll gap opening.
Claim 8
Dependent Claim 17 words
The apparatus of claim 5 with said second means being operative in relation to the strip width.
Claim 9
Dependent Claim 21 words
The apparatus of claim 6 with second means being further operative in relation to the back-up roll diameter at said stand.
Claim 10
Dependent Claim 67 words
The apparatus of claim 5 or 6 with first digital voltmeter means being provided for displaying the actual roll gap opening at said stand; second digital voltmeter means being provided in response to said third means for displaying the desired roll gap opening; said roll gap opening means being operated by matching the display of the actual gap opening with the display of the desired gap opening.
Claim 11
Dependent Claim 24 words
The apparatus of claim 8 with said third means being responsive to means for manually establishing a reference signal representative of the desired thickness.
Claim 12
Dependent Claim 33 words
The apparatus of claim 9 with said reference signal restablishing means including digital thumbwheel means and digital-to-analog converter means responsive to said digital thumbwheel means for generating said reference signal in analog form.
Claim 13
Dependent Claim 23 words
The apparatus of claim 9 with said third means including operational amplifier means responsive to said second means and to said reference signal.
Claim 14
Dependent Claim 19 words
The apparatus of claim 11 with the roll force of said roll stand being applied by an hydraulic system.
Claim 15
Dependent Claim 36 words
The apparatus of claim 12 with roll gap positioning means being provided for indicating actual roll gap opening, said third means and said first digital voltmeter means being both responsive to said roll gap positioning means.
Claim 16
Dependent Claim 59 words
The apparatus of claim 12 with said hydraulic system including cylinder means associated with the rolls of said stand for applying roll force thereto; cylinder positioning means being connected to said cylinder means for indicating actual roll gap opening at said stand; said third means and said first digital voltmeter means being both responsive to said cylinder positioning means.
Claim 17
Dependent Claim 109 words
The apparatus of claim 8 including a microprocessor responsive to digital signals from said first and second means and representative respectively of RF/M 1 and RF/M 2 for generating a first digital signal representative of ΔS=(RF/M 1 -RF/M 2 ); said microprocessor being further responsive to a second digital signal representative of a desired strip thickness H 1 ; said microprocessor being also responsive to a third digital signal representative of an actual roll gap opening; said microprocessor combining said first and second signals to provide (H 1 -ΔS) and combining (H 1 -ΔS) with said third signal to generate a digital representation of the desired roll gap opening.
Claim 18
Dependent Claim 24 words
The apparatus of claim 15 with a thumbwheel for setting said second digital signal into said microprocessor and for displaying said desired strip thickness.
Claim 19
Dependent Claim 24 words
The apparatus of claim 16 with a first digital indicator for displaying said actual roll gap opening in response to said second digital signal.
Claim 20
Dependent Claim 22 words
The apparatus of claim 17 with a second digital indicator for displaying said desired roll gap opening in response to said microprocessor.
Claim 21
Dependent Claim 19 words
The apparatus of claim 18 with said microprocessor recurrently storing said digital representation of the desired roll gap opening.

References Cited (Backward Citations)

US3404550A Cited
US3592030A Cited
US3709008A Cited
US3766761A Cited
US4323971A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-11-14 1987-05-16 1987-11-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-11-14 1991-05-16 1991-11-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-11-14 1995-05-16 1995-11-15 $7700.00 Window Closed / Lapsed

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