# US 8,740,130 B2 · Alternative method for reducing web feed rate variations induced by parent roll geometry variations

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,740,130 B2
- Document ID: US8740130B2
- Status: Granted
- Kind: B2
- Application number: 12/911,081
- Filed: 2010-10-25
- Published: 2012-04-26
- Granted: 2014-06-03
- Earliest claimed: 2010-10-25
- Assignees: The Procter & Gamble Company
- Applicants: Paul Alan Binner, Sr.
- Inventors: Paul Alan Binner, Sr.
- Web page: https://patentgrep.com/patent/US8740130B2

## CPC

- B65H 23/182: in unwinding mechanisms or in connection with unwinding operations
- B65H 2511/166: relative to diameter, eccentricity or circularity
- B65H 2513/10: Speed
- B65H 2557/24: Calculating methods; Mathematic models
- B65H: HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES

## Abstract

A method is disclosed for reducing feed rate variations when unwinding a web material to transport the web material away from the parent roll at a web takeoff point where the feed rate variations are induced by parent roll geometry variations. The method utilizes both calculated and measured data to make suitable adjustments in the driving speed for an out-of-round parent roll to maintain a relative constant feed rate. By dividing the parent roll into 1, 2, . . . n sectors, the data can be refined to a relatively high degree taking into account high speed data processing capabilities as well as operating system response times to make appropriate driving speed adjustments.

## Claims

### Claim 1

A method for reducing feed rate variations in a web material when unwinding a parent roll about a longitudinal axis to transport the web material away from the parent roll at a web takeoff point, the method comprising the steps of:
dividing the parent roll into a plurality of equal angular sectors disposed about the longitudinal axis;
using an ideal speed reference signal, SRSi, to drive the parent roll at a driving speed corresponding to a web feed rate of a round parent roll and at a drive point disposed on the outer surface either coincident with or spaced from the web takeoff point;
correlating each of the sectors at the web takeoff point with a corresponding one of the sectors at the drive point;
determining a rotational speed for each of the sectors, while at the drive point, as the parent roll is being driven;
calculating a dive point radius for each of the sectors by calculating the radius at the drive point for each of the sectors from the driving speed and the rotational speed using the formula:
Rdp=Mi/2πΩi
where Mi is the driving speed for the parent roll and Ωi is the rotational speed when each of the sectors is at the drive point;
calculating an ideal drive point radius by adding the drive point radii for all of the sectors to determine a sum and dividing the sum by the total number of sectors;
calculating a drive point correction factor for each of the sectors as a function of the drive point radius and the ideal drive point radius using the formula:
Cdp=Rdp/Rdpi
where Rdp is the drive point radius for each of the sectors and Rdpi is the ideal drive point radius;
measuring a web takeoff point radius for each of the sectors by measuring the radius at or near the web takeoff point of the parent roll for each of the sectors as the parent roll is being driven at the drive point;
calculating an ideal web takeoff point radius by adding the web takeoff point radii for all of the sectors to determine a sum and dividing the sum by the total number of sectors;
calculating a web takeoff point correction factor for each of the sectors as a function of the web takeoff point radius and the ideal web takeoff point radius using the formula:
Ctp=Rtpi/Rtp
where Rtp is the web takeoff point radius for each of the sectors and Rtpi is the ideal web takeoff point radius;
calculating a total correction factor for each of the sectors as a function of the drive point correction factor and the web takeoff point correction factor using the formula:
Ct=Cdp×Ctp
where Cdp is the drive point correction factor for each of the sectors and Ctp is the web takeoff point correction factor for each of the sectors;
multiplying the total correction factor, Ct, for each of the sectors by the ideal speed reference signal, SRSi, to establish a corrected speed reference signal, SRSiCorrected for each of the sectors; and,
adjusting the driving speed, Mi, of the parent roll for each of the sectors to a corrected driving speed, MiCorrected, as each of the sectors approaches or is at the drive point using the corrected speed reference signal, SRSiCorrected to at least approximate the web feed rate of the round parent roll to reduce feed rate variations in the web material at the web takeoff point.

### Claim 2 (depends on 1)

The method of claim 1 further comprising the step of dividing the parent roll into 1, 2, . . . n equal angular sectors about the longitudinal axis.

### Claim 3 (depends on 2)

The method of claim 2 further comprising the steps of dividing each of the angular sectors, 1, 2, . . . n, into a plurality of equal virtual sectors, 1, 2, . . . x, and creating a data table having a first column for total correction factor output data to be entered, the total correction factor calculated for each of the angular sectors, 1, 2, . . . n, being entered into the data table for all of the virtual sectors, 1, 2, . . . x, in the data table corresponding to each of the angular sectors 1, 2, . . . n.

### Claim 4 (depends on 3)

The method of claim 3 wherein the data table includes a second column for adjusting the total correction factor in one or more of the virtual sectors, 1, 2, . . . x, corresponding to one of the angular sectors, 1, 2, . . . n, in order to modulate any step between, and thereby smooth the transition from, the total correction factor for one of the angular sectors, 1, 2, . . . n, and the total correction factor for the next adjacent one of the angular sectors, 1, 2, . . . n.

### Claim 5 (depends on 4)

The method of claim 4 wherein the data table includes a third column for shifting the total correction factors in the second column for the virtual sectors, 1, 2, . . . x, corresponding to all of the angular sectors, 1, 2, . . . n and comprising a continuous data loop comprised of a total of x times n virtual sectors wherein the total correction factors for each of the virtual sectors is shifted forward or rearward by a selected number of the virtual sectors.

### Claim 6 (depends on 1)

The method of claim 1 further comprising the step of driving the parent roll with a motor-driven belt in contact with the outer surface thereof.

### Claim 7 (depends on 1)

The method of claim 1 further comprising the step of determining the rotational speed by a measurement at or near the longitudinal axis.

### Claim 8 (depends on 1)

The method of claim 1 further comprising the step of measuring the web takeoff point radius for each of the sectors using a measurement device selected from the group consisting of lasers, optical encoders, resolvers, synchros, rotary variable differential transformers (RVTD), other laser devices, ultrasonic devices, other contact measurement devices, and combinations thereof.

### Claim 9

A method for reducing feed rate variations in a web material when unwinding a parent roll by transporting the web material away from the parent roll at a web takeoff point, the method comprising the steps of:
dividing the parent roll into a selected number 1, 2, . . . n, of data collection sectors to be analyzed;
creating a data table having a sector column for entering a sector number for each of the data collection sectors, 1, 2, . . . n, the data table also having a column for entering a drive point radius, a web takeoff point radius, a drive point correction factor, a web takeoff point correction factor and a total correction factor for each of the data collection sectors, 1, 2, . . . n;
using an ideal speed reference signal, SRSi, to drive the parent roll at a driving speed corresponding to a web feed rate of a round parent roll and at a drive point being disposed on the outer surface either coincident with or spaced from the web takeoff point;
correlating each of the data collection sectors, 1, 2, . . . n, at the web takeoff point with a corresponding one of the data collection sectors, 1, 2, . . . n, at the drive point;
determining a rotational speed for each of the data collection sectors, 1, 2, . . . n, while at the drive point, as the parent roll is being driven;
calculating the drive point radius, Rdp(1, 2, . . . n), for each of the data collection sectors, 1, 2, . . . n, from the driving speed and the rotational speed using the formula:
Rdp(1, 2, . . . n)=Mi/2πΩi(1, 2, . . . n)
where Mi is the driving speed for the parent roll and Ωi(1, 2, . . . n) is the rotational speed when each of the data collection sectors, 1, 2, . . . n, is at the drive point;
entering the drive point radius, Rdp(1, 2, . . . n), in the data table for each of the data collection sectors, 1, 2, . . . n, in the column for entering the drive point radius;
calculating an ideal drive point radius, Rdpi, by adding the drive point radii, Rdp(1, 2, . . . n), for all of the data collection sectors, 1, 2, . . . n, to determine a sum and dividing the sum by the total number, n, of the data collection sectors, 1, 2, . . . n;
calculating the drive point correction factor, Cdp(1, 2, . . . n), for each of the data collection sectors, 1, 2, . . . n, as a function of the drive point radius, Rdp(1, 2, . . . n), and the ideal drive point radius, Rdpi, using the formula:
Cdp(1, 2, . . . n)=Rdp(1, 2, . . . n)/Rdpi
where Rdp(1, 2, . . . n) is the drive point radius for each of the data collection sectors, 1, 2, . . . n, and Rdpi is the ideal drive point radius;
entering the drive point correction factor, Cdp(1, 2, . . . n), in the data table for each of the data collection sectors, 1, 2, . . . n, in the column for entering the drive point correction factor;
measuring the web takeoff point radius, Rtp(1, 2, . . . n), at or near the web takeoff point of the parent roll for each of the data collection sectors, 1, 2, . . . n, as the parent roll is being driven at the drive point;
calculating an ideal web takeoff point radius, Rtpi, by adding the web takeoff point radii, Rtp(1, 2, . . . n), for all of the data collection sectors, 1, 2, . . . n, to determine a sum and dividing the sum by the total number, n, of the data collection sectors, 1, 2, . . . n;
calculating the web takeoff point correction factor, Cdp(1, 2, . . . n), for each of the data collection sectors, 1, 2, . . . n, as a function of the web takeoff point radius, Rtp(1, 2, . . . n), and the ideal web takeoff point radius, Rtpi, using the formula:
Ctp(1, 2, . . . n)=Rtpi(1, 2, . . . n)/Rtp
where Rtp(1, 2, . . . n) is the web takeoff point radius for each of the data collection sectors, 1, 2, . . . n, and Rtpi is the ideal web takeoff point radius;
entering the web takeoff point correction factor, Ctp(1, 2, . . . n), in the data table for each of the data collection sectors, 1, 2, . . . n, in the column for entering the web takeoff point correction factor;
calculating the total correction factor, Ct(1, 2, . . . n), for each of the data collection sectors, 1, 2, . . . n, as a function of the drive point correction factor, Cdp(1, 2, . . . n), and the web takeoff point correction factor, Ctp(1, 2, . . . n), using the formula:
Ct(1, 2, . . . n)=Cdp(1, 2, . . . n)×Ctp(1, 2, . . . n)
where Cdp(1, 2, . . . n) is the drive point correction factor for each of the data collection sectors, 1, 2, . . . n, and Ctp(1, 2, . . . n) is the web takeoff point correction factor for each of the data collection sectors, 1, 2, . . . n;
entering the total correction factor, Ct(1, 2, . . . n), in the data table for each of the data collection sectors, 1, 2, . . . n, in the column for entering the total correction factor;
multiplying the total correction factor, Ct(1, 2 . . . n), for each of the data collection sectors, 1, 2 . . . n, by the ideal speed reference signal, SRSi, to establish a corrected speed reference signal, SRSiCorrected, for each of the data collection sectors (1, 2 . . . n); and,
adjusting the driving speed, Mi, of the parent roll for each of the data collection sectors, 1, 2, . . . n, to a corrected driving speed, MiCorrected, as each of the data collection sectors, 1, 2, . . . n, approaches or is at the drive point using the corrected speed reference signal, SRSiCorrected, to at least approximate the web feed rate of the round parent roll to reduce feed rate variations in the web material at the web takeoff point.

### Claim 10 (depends on 9)

The method of claim 9 further comprising the step of driving the parent roll by a motor-driven belt in contact with the outer surface thereof.

### Claim 11 (depends on 9)

The method of claim 9 further comprising the step of determining the rotational speed with a measurement at an axis of the parent roll.

### Claim 12 (depends on 9)

The method of claim 9 further comprising the step of measuring the web takeoff point radius for each of the data collection sectors, 1, 2, . . . n, using a distance measurement device.

### Claim 13 (depends on 9)

The method of claim 9 further comprising the step of measuring the web takeoff point radius, Rtp(1, 2, . . . n), for each of the data collection sectors, 1, 2, . . . n, a plurality of times and averaged to determine an average takeoff point radius, RtpAverage(1, 2, . . . n), for each of the data collection sectors, 1, 2, . . . n, to be used in calculating the web takeoff point correction factors.

### Claim 14 (depends on 13)

The method of claim 13 further comprising the step of analyzing the plurality of measurements for each of the data collection sectors, 1, 2, . . . n, of the web takeoff point radius, Rtp(1, 2, . . . n) relative to the average takeoff point radius, RtpAverage(1, 2, . . . n) for the corresponding one of the data collection sectors, 1, 2, . . . n, and anomalous values deviating more than a preselected amount above or below the average takeoff point radius, RtpAverage(1, 2, . . . n), for the corresponding one of the data collection sectors, 1, 2, . . . n, are discarded and the remaining measurements for the corresponding one of the data collection sectors, 1, 2, . . . n, are re-averaged.

### Claim 15 (depends on 9)

The method of claim 9 further comprising the step of calculating the drive point radius, Rdp(1, 2, . . . n), for each of the data collection sectors, 1, 2, . . . n a plurality of times and averaged to determine an average drive point radius, RdpAverage(1, 2, . . . n), for each of the data collection sectors, 1, 2, . . . n, to be used in calculating the drive point correction factors.

### Claim 16 (depends on 15)

The method of claim 15 further comprising the step of analyzing the plurality of calculations for each of the data collection sectors, 1, 2, . . . n, of the drive point radius, Rdp(1, 2, . . . n), relative to the average drive point radius, RdpAverage(1, 2, . . . n), for the corresponding one of the data collection sectors, 1, 2, . . . n, and anomalous values deviating more than a preselected amount above or below the average drive point radius, RdpAverage(1, 2, . . . n), for the corresponding one of the data collection sectors, 1, 2, . . . n are discarded and the remaining measurements for the corresponding one of the data collection sectors, 1, 2, . . . n are re-averaged.

### Claim 17 (depends on 9)

The method of claim 9 further comprising the step of determining the total correction factor, Ct(1, 2, . . . n), a preselected time before each of the data collection sectors, 1, 2, . . . n, reaches the drive point to provide time for the response of the control system to effect an adjustment of the driving speed of the motor driven belt to coincide with the time that each of the data collection sectors, 1, 2, . . . n, reaches the drive point.

### Claim 18 (depends on 17)

The method of claim 17 further comprising the steps of dividing each of the data collection sectors, 1, 2, . . . n, into a plurality of equal virtual sectors, 1, 2, . . . x, and creating a data table having a first column for total correction factor output data to be entered, the total correction factor calculated for each of the data collection sectors, 1, 2, . . . n, being entered into the data table for all of the virtual sectors, 1, 2, . . . x, in the data table corresponding to each of the data collection sectors 1, 2, . . . n.

### Claim 19 (depends on 18)

The method of claim 18 wherein the data table includes a second column for adjusting the total correction factor in one or more of the virtual sectors, 1, 2, . . . x, corresponding to one of the data collection sectors, 1, 2, . . . n, in order to modulate any step between, and thereby smooth the transition from, the total correction factor for one of the data collection sectors, 1, 2, . . . n, and the total correction factor for the next adjacent one of the data collection sectors, 1, 2, . . . n.

### Claim 20 (depends on 19)

The method of claim 19 wherein the data table includes a third column for shifting the total correction factors in the second column for the virtual sectors, 1, 2, . . . x, corresponding to all of the data collection sectors, 1, 2, . . . n and comprising a continuous data loop comprised of a total of x times n virtual sectors wherein the total correction factors for each of the virtual sectors is shifted forward or rearward by a selected number of the virtual sectors.