Process control system

Claim 2

Method for controlling a tire calender to maintain a desired thickness and profile in a strip of sheet material including first and second layers or rubber and an intermediate layer of tire cord, in which said tire calender includes first layer thickness varying means for varying the machine direction thickness of said first layer uniformly across said first layer, strip thickness varying means for varying the machine direction thickness of said strip uniformly across said strip, first layer profile varying means for varying the thickness of the central portion of said first layer with respect to the thickness at the edge portions of said first layer, and strip profile varying means for varying the thickness of the central portion of said strip with Respect to the thickness at the edge portion of said strip, said method comprising controlling the machine direction thickness of said first layer of rubber to a selected thickness target by means of said first layer thickness varying means, controlling the total machine direction thickness of said strip to a selected thickness target by means of said strip thickness varying means, controlling the profile of said first layer of rubber to an average indication of thickness for said first layer by means of said first layer profile varying means, and controlling the profile of said strip to an average indication of thickness for said strip by means of said strip profile varying means.

Claim 3

Method for controlling a tire calender to maintain a desired thickness and profile in a strip of sheet material including first and second layers of rubber and an intermediate layer of tire cord, said method comprising measuring the thickness of said first layer at a plurality of longitudinal zones across the layer to derive a thickness profile of said first layer of rubber, measuring the total thickness of said strip at a plurality of longitudinal zones across the strip to derive a thickness profile of said strip, determining indications of overall average thickness across said first layer and across said strip from said respective thickness profiles, controlling the thickness of said first layer uniformly across said first layer in response to a deviation of said first layer overall average thickness indication from a selected first layer thickness target, controlling the thickness of said strip uniformly across said strip in response to a deviation of said strip overall average thickness indication from a selected strip thickness target, determining thickness averages, based on said respective thickness profiles, for each of the plurality of longitudinal zones on said first layer and on said strip, said zones of said first layer corresponding substantially to those of said strip, determining the deviations of said first layer zonal thickness averages from said first layer overall thickness average, controlling the profile of said first layer to said first layer overall thickness average in response to said first layer zonal deviations, determining the deviations of said strip zonal thickness averages from said strip overall thickness average, and controlling the profile of said strip to said strip overall thickness average in response to said strip zonal deviations.

Claim 4

Method for controlling a tire calender to maintain a desired thickness and profile in a strip of sheet material including first and second layers of rubber and an intermediate layer of tire cord, said method comprising measuring the thickness of said first layer at a plurality of longitudinal zones across the layer to derive a thickness profile of said first layer of rubber, measuring the total thickness of said strip at a plurality of longitudinal zones across the strip to derive a thickness profile of said strip, determining indications of overall average thickness across said first layer and across said strip from said respective thickness profiles, controlling the thickness of said first layer uniformly across said first layer in response to a deviation of said first layer overall average thickness indication from a selected first layer thickness target, controlling the thickness of said strip uniformly across said strip in response to a deviation of said strip overall average thickness indication from a selected strip thickness target, determining thickness averages, based on said respective thickness profiles, for each of the plurality of longitudinal zones on said first layer and on said strip, said zones of said first layer corresponding substantially to those of said strip, determining the deviations of said first layer zonal thickness averages from said first layer overall thickness average, controlling the profile of said first layer to said first layer overall thickness average in response to said first layer zonal deviations, determining the deviations of said strip zonal thickness averages from said strip overall thickness average, and controlling the profile of said strip to said strip overall thickness average in response to said strip zonal deviations.

Claim 5

Method of claim 2 wherein the thickness profile of said first layer is derived by fitting a curve between indications of first layer thickness obtained at discrete positions across the width of said first layer.

Claim 6

Method of claim 2 wherein the respective indications of overall average thickness across said first layer and said strip are derived from substantially the same longitudinal region.

Claim 7

Apparatus for controlling a tire calender to maintain a desired thickness and profile in a strip of sheet material including first and second layers of rubber and an intermediate layer of tire cord, in which said tire calender includes first layer thickness varying means for varying the machine direction thickness of said first layer uniformly across said first layer, second layer thickness varying means for varying the machine direction thickness of said second layer uniformly across said layer, first layer profile varying means for varying the thickness of the central portion of said first layer with respect to the thickness at the edge portions of said first layer, and second layer profile varying means for varying the thickness of the central portion of said second layer with respect to the thickness at the edge portion of said layer, said apparatus comprising means responsive to measurements of strip thickness and said first layer thickness for providing separate indications of the thickness of said first layer and a second layer thickness contRol signal to obtain a desired strip thickness, means for providing separate indications of the profile of said first layer and the profile of said second layer, means responsive to said indication of first layer thickness for controlling the thickness of said first layer of rubber to a selected target by means of said first layer uniform thickness varying means, means responsive to said second layer thickness control signal for controlling the thickness of said second layer by means of said second layer uniform thickness varying means to obtain a desired strip thickness, means responsive to said first layer profile indication for controlling the profile of said first layer of rubber to an average indication of thickness for said first layer, by means of said first layer profile varying means, and means responsive to said second laaye layer profile indication for controlling the profile of said second layer to an average indication of thickness for said second layer, by means of said second layer profile varying means.

Claim 8

Apparatus for controlling a tire calender to maintain a desired thickness and profile in a strip of sheet material including first and second layers of rubber and an intermediate layer of tire cord, in which said tire calender includes first layer thickness varying means for varying the machine direction thickness of said first layer uniformly across said first layer, second layer thickness varying means for varying the machine direction thickness of said second layer uniformly across said layer, first layer profile varying means for varying the thickness of the central portion of said first layer with respect to the thickness at the edge portions of said first layer, and second layer profile varying means for varying the thickness of the central portion of said second layer with respect to the thickness at the edge portion of said layer, said apparatus comprising means responsive to measurements of strip thickness and said first layer thickness for providing separate indications of the thickness of said first layer and a second layer thickness contRol signal to obtain a desired strip thickness, means for providing separate indications of the profile of said first layer and the profile of said second layer, means responsive to said indication of first layer thickness for controlling the thickness of said first layer of rubber to a selected target by means of said first layer uniform thickness varying means, means responsive to said second layer thickness control signal for controlling the thickness of said second layer by means of said second layer uniform thickness varying means to obtain a desired strip thickness, means responsive to said first layer profile indication for controlling the profile of said first layer of rubber to an average indication of thickness for said first layer, by means of said first layer profile varying means, and means responsive to said second laaye layer profile indication for controlling the profile of said second layer to an average indication of thickness for said second layer, by means of said second layer profile varying means.

Claim 9

Apparatus for automatically controlling a tire calender to maintain a desired thickness and cross direction profile in a strip of sheet material comprising first and second layers of rubber and an intermediate layer of tire cord, in which said first layer of rubber is formed between a first pair of coacting calender rolls having adjustable control elements at either end thereof for adjusting the spacing between said first pair of rolls to vary the thickness of said first layer of rubber, and an additional adjustable profile control element for adjusting the spacing between the ends of said first pair of rolls relative to the spacing at their centers to vary the cross direction profile of said first layer of rubber, and in which said second layer of rubber is formed between a second pair of coacting calender rolls having adjustable control elements at either end thereof for adjusting the spacing between said second pair of rolls to vary the thickness of said second layer of rubber, and an additional adjustable profile control element for adjusting the spacing between the ends of said second pair of rolls relative to the spacing at their centers to vary the cross direction profile of said second layer of rubber, said layer of tire cord being laminated between said first and second layers of rubber by adjoining calender rolls, said apparatus comprising first measuring means located adjacent the input side of one of said adjoining calender rolls for providing separate indications of the thickness of said first layer of rubber at three cross direction positions thereof, each position lying with a different one of three longitudinal bottom layer zones, first averaging means associated with said first measuring means to determine averages of each of said separate thickness indications and to determine in addition an overall average of the thickness of said first layer, second measuring means located at the strip output side of said adjoining calender rolls and traversing substantially the entire width of said strip to provide a plurality of separate indications of the total thickness of said strip, each indication corresponding to a different transverse position on said strip, second averaging means associated with said second measuring means to determine averages of said separate indications of total thickness and to determine in addition an overall average of the total thickness of said strip, means for subtracting said overall average of thickness of said first layer from a selected first layer thickness target to provide a first layer thickness deviation, a first layer thickness controller for actuating each of said adjustable control elements on said first pair of rolls equally in response to said first layer thickness deviation, means for subtracting said overall total thickness average from a selected total thickness target to provide a resultant total thickness deviation, means for subtracting sAid first layer thickness deviation from said total thickness deviation to provide a second layer thickness deviation, a second layer thickness controller for actuating each of said adjustable control elements on said second pair of rolls equally in response to said second layer thickness deviation, computer means for fitting a regression curve between said average indications of first layer thickness, said curve including as points thereon each of said average indications and representing an approximation of a cross direction profile of said first layer with respect to thickness, means for integrating said regression curve between predetermined limits representing substantially the edges of said three zones to determine the average thickness of said first layer across each of said zones, means for averaging substantially all of said separate total thickness average indications lying within each one of three longitudinal zones on said strip, said strip zones being coextensive with said first layer longitudinal zones, to determine the average total thickness across each of said strip zones, means for subtracting each of the zonal averages of thickness of said first layer from said overall average of first layer thickness to determine deviations from a flat profile for each zone of said first layer, and for subtracting each of the zonal averages of total thickness from said overall average of total thickness to determine deviations from a flat profile for each zone of said total strip, a first layer profile controller for actuating said control elements and said additional adjustable profile control element on said first pair of rolls in response to said first layer zonal deviations, to bring the cross direction profile of said first layer to a substantially flat condition, and a second layer profile controller for actuating said control elements and said additional adjustable profile control element on said second pair of rolls in response to any one of said total thickness zonal deviations being different from one of said first layer zonal deviations corresponding to the same zone, to bring the cross direction profile of said second layer to a substantially flat condition.

Claim 10

Apparatus for automatically controlling a tire calender to maintain a desired thickness and cross direction profile in a strip of sheet material comprising first and second layers of rubber and an intermediate layer of tire cord, in which said first layer of rubber is formed between a first pair of coacting calender rolls having adjustable control elements at either end thereof for adjusting the spacing between said first pair of rolls to vary the thickness of said first layer of rubber, and an additional adjustable profile control element for adjusting the spacing between the ends of said first pair of rolls relative to the spacing at their centers to vary the cross direction profile of said first layer of rubber, and in which said second layer of rubber is formed between a second pair of coacting calender rolls having adjustable control elements at either end thereof for adjusting the spacing between said second pair of rolls to vary the thickness of said second layer of rubber, and an additional adjustable profile control element for adjusting the spacing between the ends of said second pair of rolls relative to the spacing at their centers to vary the cross direction profile of said second layer of rubber, said layer of tire cord being laminated between said first and second layers of rubber by adjoining calender rolls, said apparatus comprising first measuring means located adjacent the input side of one of said adjoining calender rolls for providing separate indications of the thickness of said first layer of rubber at three cross direction positions thereof, each position lying with a different one of three longitudinal bottom layer zones, first averaging means associated with said first measuring means to determine averages of each of said separate thickness indications and to determine in addition an overall average of the thickness of said first layer, second measuring means located at the strip output side of said adjoining calender rolls and traversing substantially the entire width of said strip to provide a plurality of separate indications of the total thickness of said strip, each indication corresponding to a different transverse position on said strip, second averaging means associated with said second measuring means to determine averages of said separate indications of total thickness and to determine in addition an overall average of the total thickness of said strip, means for subtracting said overall average of thickness of said first layer from a selected first layer thickness target to provide a first layer thickness deviation, a first layer thickness controller for actuating each of said adjustable control elements on said first pair of rolls equally in response to said first layer thickness deviation, means for subtracting said overall total thickness average from a selected total thickness target to provide a resultant total thickness deviation, means for subtracting sAid first layer thickness deviation from said total thickness deviation to provide a second layer thickness deviation, a second layer thickness controller for actuating each of said adjustable control elements on said second pair of rolls equally in response to said second layer thickness deviation, computer means for fitting a regression curve between said average indications of first layer thickness, said curve including as points thereon each of said average indications and representing an approximation of a cross direction profile of said first layer with respect to thickness, means for integrating said regression curve between predetermined limits representing substantially the edges of said three zones to determine the average thickness of said first layer across each of said zones, means for averaging substantially all of said separate total thickness average indications lying within each one of three longitudinal zones on said strip, said strip zones being coextensive with said first layer longitudinal zones, to determine the average total thickness across each of said strip zones, means for subtracting each of the zonal averages of thickness of said first layer from said overall average of first layer thickness to determine deviations from a flat profile for each zone of said first layer, and for subtracting each of the zonal averages of total thickness from said overall average of total thickness to determine deviations from a flat profile for each zone of said total strip, a first layer profile controller for actuating said control elements and said additional adjustable profile control element on said first pair of rolls in response to said first layer zonal deviations, to bring the cross direction profile of said first layer to a substantially flat condition, and a second layer profile controller for actuating said control elements and said additional adjustable profile control element on said second pair of rolls in response to any one of said total thickness zonal deviations being different from one of said first layer zonal deviations corresponding to the same zone, to bring the cross direction profile of said second layer to a substantially flat condition.

Claim 15

In a system for controlling thickness variations of first and second layers of material respectively laminated onto first and second sides of a moving substrate sheet by first and second coating application stations, each of said stations including means for controlling the thickness of the coating it applies to the substrate sheet, said system comprising: scanning gauge means downstream of the stations for measuring the total thickness of the substrate, means for scanning the scanning gauge means in a direction between the sheet edges, said scanning gauge means being scanned several times, means for accumulating the signal derived from several scans of the scanning gauge means, means upstream of the first station for measuring the thickness of the first coating prior to the first coating being applied to the substrate sheet, said upstream measuring means including coating thickness gauge means fixedly maintained during each scan for monitoring plural different cross sheet zones of the coating thickness, means responsive to the upstream measuring means for deriving a control signal for the control means of the first station, and means responsive to the upstream measuring means and the accumulated signal for deriving a control signal for the control means of the second station.

Claim 16

In a system for controlling thickness variations of first and second layers of material respectively laminated onto first and second sides of a moving substrate sheet by first and second coating application stations, each of said stations including means for controlling the thickness of the coating it applies to the substrate sheet, said system comprising: scanning gauge means downstream of the stations for measuring the total thickness of the substrate, means for scanning the scanning gauge means in a direction between the sheet edges, said scanning gauge means being scanned several times, means for accumulating the signal derived from several scans of the scanning gauge means, means upstream of the first station for measuring the thickness of the first coating prior to the first coating being applied to the substrate sheet, said upstream measuring means including coating thickness gauge means fixedly maintained during each scan for monitoring plural different cross sheet zones of the coating thickness, means responsive to the upstream measuring means for deriving a control signal for the control means of the first station, and means responsive to the upstream measuring means and the accumulated signal for deriving a control signal for the control means of the second station.

Claim 17

A system in accordance with claim 9 wherein the system is for controlling machine direction thickness variations of the first and second layers and each of said stations includes means for controlling the machine direction thickness of the coating it applies to the sheet, said means for accumulating including means for deriving a first signal indicative of the total thickness machine direction variations over the several scans, said means for deriving the control signal for the first station including means for additively combining the signals from the different zones as derived from the fixedly maintained gauge means to derive a signal indicative of the first layer machine direction variations, whereby the control signal for the first station is for the machine direction of the first layEr, and said means for deriving the control signal for the second station includes means for combining signals that are functions of the first layer and total thickness machine direction variations.

Claim 18

A system in accordance with claim 9 wherein the system is for controlling cross direction thickness variations of the first and second layers and each of said stations includes means for controlling the cross direction thickness of the coating it applies to the sheet, means responsive to the upstream measuring means for the different zones for deriving a control signal for the control means of the first station, means responsive to the scanning gauge for deriving indications of the total sheet thickness in each of the cross sheet zones in response to an accumulation of total sheet thickness measurements in the zones as derived from the several scans, and means for combining signals for the different corresponding zones as derived from the several scans of the scanning gauge means and the fixedly maintained gauge means to derive a control signal for the control means of the second station.

Claim 19

In a system for controlling machine and cross direction thickness variations of first and second layers of material respectively laminated onto first and second sides of a moving substrate sheet by first and second coating aplication stations, each of said stations including first means for controlling the machine direction thickness of the coating it applies to the substrate sheet and second means for controlling the cross direction thickness profile of the coating it applies to the substrate sheet, said system comprising: scanning gauge means downstream of the stations for measuring the total thickness of the substrate sheet and the two layers, means for scanning the scanning gauge means in a direction between the sheet edges, said scanning means being scanned several times, means for accumulating the signal derived from several scans of the scanning gauge means, means upstream of one of the stations for measuring the thickness of the first coating prior to the first coating being applied to the substrate sheet, said upstream measuring means including means fixedly maintained during each scan for monitoring plural different cross sheet zones of the coating thickness, means responsive to the upstream measuring means for deriving a control signal for the first means of the first station, means responsive to the accumulating means for deriving a signal indicative of machine direction variations for the several scans over all of the zones, means responsive to the upstream measuring means and the signal indicative of the machine direction variations over all of the zones for deriving a control signal for the first means of the second station, means responsive to the upstream measuring means for the different zones for deriving a control signal for the second means of the first station, means responsive to the scanning gauge for deriving indications of the total sheet thickness in each of the cross sheet zones in response to an accumulation of total sheet thickness measurements in the zones as derived from the several scans, and means for combining signals for the different corresponding zones as derived from the several scans of the scanning gauge means and the fixedly maintained gauge means to derive a control signal for the second means of the second station.

Claim 20

In a system for controlling machine and cross direction thickness variations of first and second layers of material respectively laminated onto first and second sides of a moving substrate sheet by first and second coating aplication stations, each of said stations including first means for controlling the machine direction thickness of the coating it applies to the substrate sheet and second means for controlling the cross direction thickness profile of the coating it applies to the substrate sheet, said system comprising: scanning gauge means downstream of the stations for measuring the total thickness of the substrate sheet and the two layers, means for scanning the scanning gauge means in a direction between the sheet edges, said scanning means being scanned several times, means for accumulating the signal derived from several scans of the scanning gauge means, means upstream of one of the stations for measuring the thickness of the first coating prior to the first coating being applied to the substrate sheet, said upstream measuring means including means fixedly maintained during each scan for monitoring plural different cross sheet zones of the coating thickness, means responsive to the upstream measuring means for deriving a control signal for the first means of the first station, means responsive to the accumulating means for deriving a signal indicative of machine direction variations for the several scans over all of the zones, means responsive to the upstream measuring means and the signal indicative of the machine direction variations over all of the zones for deriving a control signal for the first means of the second station, means responsive to the upstream measuring means for the different zones for deriving a control signal for the second means of the first station, means responsive to the scanning gauge for deriving indications of the total sheet thickness in each of the cross sheet zones in response to an accumulation of total sheet thickness measurements in the zones as derived from the several scans, and means for combining signals for the different corresponding zones as derived from the several scans of the scanning gauge means and the fixedly maintained gauge means to derive a control signal for the second means of the second station.

Claim 25

The method of claim 14 wherein the method is for controlling machine direction thickness variations of the first and second layers and each of said stations includes means for controlling the machine direction thickness of the coating it applies to the sheet, said accumulating step including deriving a first signal indicative of the total thickness machine direction variations over the several scans, and controlling the machine direction thickness of the first layer as applied by the first station in response to an additive combination of the signals derived from the different zones from the fixedly maintained gauge means, and controlling the machine direction thickness of the second layer as applied by the second station in response to an accumulation of the signals from the scanning gauge over the several scans for all of the different zones and a function of the additive combination of the signals.

Claim 26

The method of claim 14 wherein the system is for controlling cross direction thickness variations of the first and second layers and each of said stations includes means for controlling the cross direction thickness of the coating it applies to the sheet, said method further comprising controlling the cross direction variations of the first lAyer in response to measurements derived from the different zones by the upstream measuring means, separately accumulating responses of the scanning gauge in each of the zones over the several scans to derive indications of the total sheet thickness in each of the cross sheet zones, and controlling the cross direction variations of the second layer by controlling the control means of the second station in response to a combination of signals for the different corresponding zones as derived from the separately accumulated responses and the fixedly maintained gauge means.

Claim 29

The method of claim 17 wherein the first and fourth indications are derived by averaging the fixed and scanning gauge measurements over the same interval.

Claim 30

The method of claim 18 wherein two of said fixed gauges are provided, and moving one of said gauges from one of said zones to another of said zones between the several scans.

Claim 31

Apparatus for controlling a tire calender to maintain a desired thickness and profile in a strip of sheet material including first and second layers of rubber and an intermediate layer of tire cord, in which said tire calender includes first layer thickness varying means for varying the machine direction thickness of said first layer uniformly across said first layer, strip thickness varyIng means for varying the machine direction thickness of said strip uniformly across said strip, first layer profile varying means for varying the thickness of one cross direction portion of said first layer with respect to the thickness at another cross sheet portion of said first layer, and strip profile varying means for varying the thickness of one cross direction portion of said strip with respect to the thickness at another cross direction portion of said strip, said apparatus comprising: a total thickness gauge for the strip, means for scanning the total thickness gauge between the strip edges a plurality of times, said total thickness gauge being located downstream of all of said varying means; means responsive to total thickness measurements of the thickness gauge to derive: a first indication of the total thickness as averaged over several of said scans, second indications of the total thickness in each of a plurality of longitudinal zones on the strip as averaged over several of the scans, and third indications of the deviations of the second indications from an indication of the total average thickness; means for measuring the thickness of said first layer of rubber at the plural zones, said first layer measuring means including further gauges that are maintained in a fixed position while the several scans of the scanning gauge occur; means responsive to the first layer thickness measurements of the first layer measuring means for deriving: a fourth indication of the average thickness of the first layer and fifth indications of the thickness of the first layer in each of the zones; means for algebraically combining the first and fourth indications to derive a sixth indication; means responsive to the measurements from the fixed position gauges for deriving a control signal for said first layer thickness varying means so that the machine direction thickness of said first layer is controlled to a selected value; means for comparing the measurements from the fixed gauges measuring the different zones for deriving a control signal for the first layer profile varying means whereby the profile of said first layer is controlled to a selected value; means responsive to the sixth indication for deriving a control signal for the strip thickness varying means whereby the machine direction thickness of said strip is controlled to a selected value; and means for comparing the second and fifth indications for corresponding zones for deriving a control signal for the strip profile varying means to control the profile of said strip.

Claim 32

Apparatus for controlling a tire calender to maintain a desired thickness and profile in a strip of sheet material including first and second layers of rubber and an intermediate layer of tire cord, in which said tire calender includes first layer thickness varying means for varying the machine direction thickness of said first layer uniformly across said first layer, strip thickness varyIng means for varying the machine direction thickness of said strip uniformly across said strip, first layer profile varying means for varying the thickness of one cross direction portion of said first layer with respect to the thickness at another cross sheet portion of said first layer, and strip profile varying means for varying the thickness of one cross direction portion of said strip with respect to the thickness at another cross direction portion of said strip, said apparatus comprising: a total thickness gauge for the strip, means for scanning the total thickness gauge between the strip edges a plurality of times, said total thickness gauge being located downstream of all of said varying means; means responsive to total thickness measurements of the thickness gauge to derive: a first indication of the total thickness as averaged over several of said scans, second indications of the total thickness in each of a plurality of longitudinal zones on the strip as averaged over several of the scans, and third indications of the deviations of the second indications from an indication of the total average thickness; means for measuring the thickness of said first layer of rubber at the plural zones, said first layer measuring means including further gauges that are maintained in a fixed position while the several scans of the scanning gauge occur; means responsive to the first layer thickness measurements of the first layer measuring means for deriving: a fourth indication of the average thickness of the first layer and fifth indications of the thickness of the first layer in each of the zones; means for algebraically combining the first and fourth indications to derive a sixth indication; means responsive to the measurements from the fixed position gauges for deriving a control signal for said first layer thickness varying means so that the machine direction thickness of said first layer is controlled to a selected value; means for comparing the measurements from the fixed gauges measuring the different zones for deriving a control signal for the first layer profile varying means whereby the profile of said first layer is controlled to a selected value; means responsive to the sixth indication for deriving a control signal for the strip thickness varying means whereby the machine direction thickness of said strip is controlled to a selected value; and means for comparing the second and fifth indications for corresponding zones for deriving a control signal for the strip profile varying means to control the profile of said strip.

Claim 35

The system of claim 21 wherein the fixed gauge means monitors the property in each of a plurality of longitudinally extending zones at different locations across the sheet, said means for accumulating including means for separately accumulating the scanning gauge response from the plural scans for each of the zones, and said means for combining includes means for separately combining the accumulated responses from the different zones with the monitored property derived from the fixed gauge means in the corresponding zones.

Claim 36

The system of claim 22 further including means for accumulating the response derived from the fixed gauge means over the same interval as the accumulated response of the scanning gauge means.

Claim 37

The system of claim 23 further including means for comparing the separately accuMulated responses from the different zones to derive a signal indicative of cross direction variations of the sheet.

Claim 38

The system of claim 22 further including means for comparing the separately accumulated responses from the different zones to derive a signal indicative of cross direction variations of the sheet.

Claim 39

The system of claim 22 further including means for deriving a curve fit of the property between the plurality of zones, means for averaging the derived curve fit in each of the zones, and means for coupling the averaged curve fit in each of the zones as one input to the means for separately combining.

Claim 40

The system of claim 21 further including means for accumulating the response derived from the fixed gauge means over the same interval as the accumulated response of the scanning gauge means.

Claim 41

The system of claim 21 wherein the fixed gauge means monitors the property in each of a plurality of longitudinally extending zones at different locations across the sheet, each of said zones having a cross direction extent less than the scanned cross direction extent, said means for accumulating including means for accumulating the scanning gauge response from the plural scans for each of the zones to derive a first machine direction indicating signal, and said means for combining includes means for additively combining signals indicative of the monitored property as derived from the fixed gauge means in the different zones to derive a second machine direction indicating signal, and for combining the first and second machine direction indicating signals to derive a further signal indicative of a machine direction property of the sheet.

Claim 44

The method of claim 29 wherein the fixed gauge means monitors the property in each of a plurality of longitudinally extending zones at different locations across the sheet, said accumulating step including separately accumulating the scanning gauge response from the plural scans for each of the zones, and said combining step includes separately combining the accumulated responses from the different zones with the monitored property indication derived from the fixed gauge means in the corresponding zones.

Claim 45

The method of claim 30 further including accumulating the response derived from the fixed gauge means over the same interval as the accumulated response of the scanning gauge means.

Claim 46

The method of claim 31 further including comparing the separately accumulated responses from the different zones, and controlling cross direction variations of the sheet in response to the comparison.

Claim 47

The method of claim 29 further including comparing the separately accumulated responses from the different zones, and controlling cross direction variations of the sheet in response to the comparison.

Claim 48

The method of claim 29 further including accumulating the response derived from the fixed gauge means over the same interval as the accumulated response of the scanning gauge means.

Claim 49

The method of claim 29 wherein the fixed gauge means monitors the property in each of a plurality of longitudinally extending zones at different locations across the sheet, each of said zones having a cross direction extent less than the scanned cross direction extent, said accumulating step including accumulating the scanning gauge response from the plural scans for each of the zones to derive a first machine direction indicating signal, and said combining step includes additively combIning signals indicative of the monitored property as derived from the fixed gauge means in the different zones to derive a second machine direction indicating signal, and controlling a machine direction property of the sheet in response to a combination of the first and second machine direction indicating signals.

Claim 50

In a system for controlling the application of a coating applied by a coating station to a moving substrate sheet, scanning gauge means for measuring the thickness of the sheet, said scanning gauge means being scanned in a direction between the sheet edges a plurality of times, further measuring means for monitoring the thickness of the coating prior to application of the coating to the sheet, said further measuring means including gauge means fixedly maintained during each scan, means for accumulating a response of the scanning gauge means from several of the scans, and means responsive to the accumulated response and a response from the further measuring means for combining signals that are functions of said responses to derive a thickness control signal for the coating station.

Claim 51

In a system for controlling the application of a coating applied by a coating station to a moving substrate sheet, scanning gauge means for measuring the thickness of the sheet, said scanning gauge means being scanned in a direction between the sheet edges a plurality of times, further measuring means for monitoring the thickness of the coating prior to application of the coating to the sheet, said further measuring means including gauge means fixedly maintained during each scan, means for accumulating a response of the scanning gauge means from several of the scans, and means responsive to the accumulated response and a response from the further measuring means for combining signals that are functions of said responses to derive a thickness control signal for the coating station.