US3857023A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for improving the uniformity of the basic weight of a fabric
Assignee: Industrial Nucleonics Corp
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Filing: 1973-06-21
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Granted: 1974-12-24
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Expires: 1993-06-21
Abstract
Abstract A method and apparatus is disclosed for regulating the basis weight on the exit side of fabric heat set apparatus to improve the uniformity of the basis weight of the fabric in a mill roll or other selected fabric length. A measured exit fabric basis weight is averaged across the width of the fabric and the average final basis weight is compared with a selected target basis weight to produce a measured final basis weight error signal. The latter signal may be fed into an ''''on time'''' proportioning auto control which produces an on-time control signal proportioned to the measured final basis weight error signal and adjusts a motor operated potentiometer to vary a calculated percent moisture signal from an initially manually set estimated magnitude of the percent moisture in the fabric on the entrance side of the heat set apparatus. The percent moisture signal along with signals representing measured entrance basis weight, measured entrance fabric width, measured entrance speed, measured exit speed, and standard fabric width are fed as inputs into a calculated final basis weight computer, which computes a calculated or predicted final basis weight. The calculated basis weight is averaged in a profile averaging computer and compared with the selected target basis weight to produce a calculated basis weight error signal. The latter error signal is fed into a speed proportioning auto control which produces a speed on-time control signal proportional to the calculated final basis weight error signal. A speed motor operated potentiometer is adjusted in response to the speed on-time control signal to vary a overfeed speed control signal from an initially manually set signal. The overfeed speed control signal adjusts the speed of the fabric overfeed means which feeds fabric onto a tenter frame at the entrance end of a heat set oven at a speed greater than the speed of the tenter. By adjusting the speed of the overfeed means in accordance with the calculated basis weight error signal shrinkage of the fabric is regulated in order to improve the uniformity of the fabric final basis weight.
Inventors
- 👤 R Mccall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 04:59
CPC Classifications
D; D06; D06C; D06C29/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
461 words
A method of improving the uniformity of the basis weight of a travelling web of textile fabric at the exit side of fabric heat setting apparatus which includes a source of wet fabric supply, means for heat setting the fabric, tentering means for obtaining a uniform standard width of the fabric at the exit side of said heat setting means and for regulating the longitudinal shrinkage of the fabric by said heat setting means, overfeed means for moving said fabric web from the source of supply onto said tentering means, means for winding up said fabric web after it has passed through said heat setting means and means, for varying the speed of said overfeed means, comprising the steps of generating a signal BW1 indicative of the measured basis weight of the fabric on the entry side of said heat setting means, generating a signal W1 indicative of the measured width of the fabric on the entry side of said heat setting means, generating a signal S1 indicative of the measured speed of the web on the supply side of said tentering means, generating a signal S3 indicative of the measured speed of the web on the exit side of said heat setting means, generating a signal BW2 indicative of the measured basis weight of said fabric on the exit side of said heat setting means, generating a signal BWt indicative of a predetermined target basis weight for the web on the exit side of the heat setting means, comparing the signal BW2 with the signal BWt and producing an error signal BW2-BWt which corresponds with the deviation of the signal BW2 from BWt, initially setting a signal D1 indicative of an estimated percent moisture content of the web on the entry side of the heat setting means, and thereafter automatically increasing the signal D1 to indicate an increased percentage moisture when BW2 is greater than the BWt and decreasing the signal D1 to indicate a decreased Percentage moisture when BW2 is less than BWt in proportion to the magnitude of deviation of BW2 from BWt, generating a signal BWc indicative of a calculated exit basis weight according to the formula: BWc (BW1/(1 + D1)).(W1/Ws).(S1/S3) wherein BWc, BW1, W1, S1, S3 and D1 respectively represent previous indicated signals and Ws represents a preset signal indicative of a selected standard width for said fabric at the exit side of the heat setting means, comparing the signal BWc with the signal BWt and generating an error signal BWc-BWt which corresponds with the deviation of BWc from BWt and increasing the speed of the overfeed means when the signal BWc is less than the signal BWt and decreasing the speed of the overfeed means when the signal BWc is greater than the signal BWt.
Claim 2
Independent Claim
461 words
A method of improving the uniformity of the basis weight of a travelling web of textile fabric at the exit side of fabric heat setting apparatus which includes a source of wet fabric supply, means for heat setting the fabric, tentering means for obtaining a uniform standard width of the fabric at the exit side of said heat setting means and for regulating the longitudinal shrinkage of the fabric by said heat setting means, overfeed means for moving said fabric web from the source of supply onto said tentering means, means for winding up said fabric web after it has passed through said heat setting means and means, for varying the speed of said overfeed means, comprising the steps of generating a signal BW1 indicative of the measured basis weight of the fabric on the entry side of said heat setting means, generating a signal W1 indicative of the measured width of the fabric on the entry side of said heat setting means, generating a signal S1 indicative of the measured speed of the web on the supply side of said tentering means, generating a signal S3 indicative of the measured speed of the web on the exit side of said heat setting means, generating a signal BW2 indicative of the measured basis weight of said fabric on the exit side of said heat setting means, generating a signal BWt indicative of a predetermined target basis weight for the web on the exit side of the heat setting means, comparing the signal BW2 with the signal BWt and producing an error signal BW2-BWt which corresponds with the deviation of the signal BW2 from BWt, initially setting a signal D1 indicative of an estimated percent moisture content of the web on the entry side of the heat setting means, and thereafter automatically increasing the signal D1 to indicate an increased percentage moisture when BW2 is greater than the BWt and decreasing the signal D1 to indicate a decreased Percentage moisture when BW2 is less than BWt in proportion to the magnitude of deviation of BW2 from BWt, generating a signal BWc indicative of a calculated exit basis weight according to the formula: BWc (BW1/(1 + D1)).(W1/Ws).(S1/S3) wherein BWc, BW1, W1, S1, S3 and D1 respectively represent previous indicated signals and Ws represents a preset signal indicative of a selected standard width for said fabric at the exit side of the heat setting means, comparing the signal BWc with the signal BWt and generating an error signal BWc-BWt which corresponds with the deviation of BWc from BWt and increasing the speed of the overfeed means when the signal BWc is less than the signal BWt and decreasing the speed of the overfeed means when the signal BWc is greater than the signal BWt.
Claim 3
Independent Claim
560 words
A system for improving the uniformity of the basis weight of a travelling web of knit fabric on the exit side of fabric heat setting apparatus which apparatus includes a web fabric supply source, means for heat setting the fabric, tentering means for obtaining a uniform standard width of the fabric at the exit side of said heat setting means and for regulating the longitudinal shrinkage of the fabric by said heat setting means, overfeed means for moving said fabric web from the source of supply onto said tentering means, means for winding up said fabric web after it has passed through said heat setting means, and variable speed drive means for said overfeed means, comprising means for generating a signal BW1 indicative of the measured basis weight of the fabric on the entry side of said heat setting means, means for generating a signal W1 indicative of the measured width of the fabric on the entry side of said heat setting means, means for generating a signal S1 indicative of the measured speed of the web on the supply side of said tentering means, means for generating a signal S3 indicative of the measured speed of the web on the exit side of said heat setting means, means for generating a signal BW2 indicative of the measured basis weight of said fabric on the exit side of said heat setting means, means for generating a signal BWt indicative of a predetermined target basis weight for the web on the exit side of the heat setting means, means for comparing the signal BW2 with the signal BWt and producing an error signal BW2-BWt which corresponds with the deviation of the signal BW2 from BWt, variable means for generating a signal D1 representing percent moisture content of the web on the entry side of the heat setting means including means for manually setting said moisture signal generating means to an initial signal magnitude means responsive to the error signal BWc-BWt for automatically increasing the signal D1 to indicate an increased percent moisture when BW2 is greater than the BWt and for decreasing the signal D1 to indicate a decreased percentage moisture when BW2 is less than BWt in proportion to the magnitude of deviation of BW2 from BWt, computer means for generating a signal BWc indicative of a calculated exit basis weight according to the formula: BWc (BW1/(1 + D1)).(W1/Ws).(S1/S3) wherein BWc, BW1, W1, S1, S3 and D1 respectively represent signals previously defined and Ws represents a preset signal indicative of a selected standard width for said fabric at the exit side of the heat setting means, means for comparing the signal BWc with the signal BWt and for generating an error signal BWc-BWt which corresponds with the deviation of BWc from BWt, means for generating a speed control signal which controls the speed of said variable speed drive including means for manually setting an initial speed control signal, auto control means for varying the speed control signal generating means to increase the speed of said variable speed drive means when the signal BWc is less than the signal BWt and for varying the speed control signal generating means to decrease the speed of said variable speed drive means when the signal BWc is greater than the signal BWt in proportion to the magnitude of the deviation of BWc from BWt.
Claim 4
Independent Claim
560 words
A system for improving the uniformity of the basis weight of a travelling web of knit fabric on the exit side of fabric heat setting apparatus which apparatus includes a web fabric supply source, means for heat setting the fabric, tentering means for obtaining a uniform standard width of the fabric at the exit side of said heat setting means and for regulating the longitudinal shrinkage of the fabric by said heat setting means, overfeed means for moving said fabric web from the source of supply onto said tentering means, means for winding up said fabric web after it has passed through said heat setting means, and variable speed drive means for said overfeed means, comprising means for generating a signal BW1 indicative of the measured basis weight of the fabric on the entry side of said heat setting means, means for generating a signal W1 indicative of the measured width of the fabric on the entry side of said heat setting means, means for generating a signal S1 indicative of the measured speed of the web on the supply side of said tentering means, means for generating a signal S3 indicative of the measured speed of the web on the exit side of said heat setting means, means for generating a signal BW2 indicative of the measured basis weight of said fabric on the exit side of said heat setting means, means for generating a signal BWt indicative of a predetermined target basis weight for the web on the exit side of the heat setting means, means for comparing the signal BW2 with the signal BWt and producing an error signal BW2-BWt which corresponds with the deviation of the signal BW2 from BWt, variable means for generating a signal D1 representing percent moisture content of the web on the entry side of the heat setting means including means for manually setting said moisture signal generating means to an initial signal magnitude means responsive to the error signal BWc-BWt for automatically increasing the signal D1 to indicate an increased percent moisture when BW2 is greater than the BWt and for decreasing the signal D1 to indicate a decreased percentage moisture when BW2 is less than BWt in proportion to the magnitude of deviation of BW2 from BWt, computer means for generating a signal BWc indicative of a calculated exit basis weight according to the formula: BWc (BW1/(1 + D1)).(W1/Ws).(S1/S3) wherein BWc, BW1, W1, S1, S3 and D1 respectively represent signals previously defined and Ws represents a preset signal indicative of a selected standard width for said fabric at the exit side of the heat setting means, means for comparing the signal BWc with the signal BWt and for generating an error signal BWc-BWt which corresponds with the deviation of BWc from BWt, means for generating a speed control signal which controls the speed of said variable speed drive including means for manually setting an initial speed control signal, auto control means for varying the speed control signal generating means to increase the speed of said variable speed drive means when the signal BWc is less than the signal BWt and for varying the speed control signal generating means to decrease the speed of said variable speed drive means when the signal BWc is greater than the signal BWt in proportion to the magnitude of the deviation of BWc from BWt.
Claim 5
Dependent Claim
45 words
The system set forth in claim 2 wherein the means for generating the signals BW1 and BW2 are cross web scanning basis weight gauges and the signals BW1 and BW2 are instantaneous signals corresponding with the positions of the gauges with respect to the web.
Claim 6
Dependent Claim
16 words
The system set forth in claim 3 wherein said basis weight gauges are beta ray gauges.
Claim 7
Dependent Claim
101 words
The system set forth in claim 3 wherein said means for comparing the signal BW2 with the signal BWt is a profile averaging computer which produces an average value of BW2 over a predetermined time period and includes a comparing circuit by which the average value of signal BW2 is compared with the signal BWt, and wherein said means for comparing BWc with BWt is likewise a profile averaging computer which produces an average value of BWc over a predetermined time period and includes a comparing circuit by which the average value of signal BWc is compared with the signal BWt.
Claim 8
Dependent Claim
26 words
The system set forth in claim 5 wherein said means for generating said moisture signal D1 and speed control signal generating means are motor operated potentiometers.
Claim 9
Dependent Claim
399 words
A machine for heat setting a travelling web of textile fabric, said machine including means providing a heated environment through which the textile web travels for heat setting the fabric, said heat setting means having an entry side and an exit side, tentering means extending through said heat setting means for carrying the web through said heat setting means, obtaining a uniform standard fabric width at the exit side of the heat setting means, and for regulating longitudinal shrinkage of the fabric, overfeed means on the entry side of said heat setting means for moving the fabric web from a source of supply onto the tentering means at a speed greater than the speed of said tentering means, means for winding the fabric web after it has passed through said heat setting means, means for varying the speed of said overfeed means, a system for controlling the final basis weight of said textile web comprising means providing a target signal indicative of a desired final basis weight on the exit side of said heat setting means, means providing a feedback signal indicative of the actual final basis weight, means comparing said desired final basis weight target signal with said feedback signal to provide a first error signal representing any difference between said signals, means providing a signal representing the percent moisture in the fabric on the entry side of said heat setting means, means responsive to said first error signal for automatically varying said percent moisture signal in proportion to the magnitude of said first error signal, means providing a predicted final basis weight signal derived from the basis weight of the fabric coming from supply, the speed of said fabric coming from supply, the width of the fabric coming from supply, the speed of the fabric on the exit side of the heat setting means, the standard exit width of said fabric, and said percent moisture signal, means for comparing said predicted basis weight signal with said target signal to provide a second error signal representing any difference between said predicted and target signals, and means responsive to said second error signal to provide a control signal to vary the speed of said overfeed speed varying means in order to control the amount of fabric overfeed onto said tentering means and thus to control the amount of fabric shrinkage which effects the final basis weight of the fabric.
Claim 10
Dependent Claim
399 words
A machine for heat setting a travelling web of textile fabric, said machine including means providing a heated environment through which the textile web travels for heat setting the fabric, said heat setting means having an entry side and an exit side, tentering means extending through said heat setting means for carrying the web through said heat setting means, obtaining a uniform standard fabric width at the exit side of the heat setting means, and for regulating longitudinal shrinkage of the fabric, overfeed means on the entry side of said heat setting means for moving the fabric web from a source of supply onto the tentering means at a speed greater than the speed of said tentering means, means for winding the fabric web after it has passed through said heat setting means, means for varying the speed of said overfeed means, a system for controlling the final basis weight of said textile web comprising means providing a target signal indicative of a desired final basis weight on the exit side of said heat setting means, means providing a feedback signal indicative of the actual final basis weight, means comparing said desired final basis weight target signal with said feedback signal to provide a first error signal representing any difference between said signals, means providing a signal representing the percent moisture in the fabric on the entry side of said heat setting means, means responsive to said first error signal for automatically varying said percent moisture signal in proportion to the magnitude of said first error signal, means providing a predicted final basis weight signal derived from the basis weight of the fabric coming from supply, the speed of said fabric coming from supply, the width of the fabric coming from supply, the speed of the fabric on the exit side of the heat setting means, the standard exit width of said fabric, and said percent moisture signal, means for comparing said predicted basis weight signal with said target signal to provide a second error signal representing any difference between said predicted and target signals, and means responsive to said second error signal to provide a control signal to vary the speed of said overfeed speed varying means in order to control the amount of fabric overfeed onto said tentering means and thus to control the amount of fabric shrinkage which effects the final basis weight of the fabric.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |