US5659538A — Diaper registration control system

Claim 1

Independent Claim 194 words

An improved closed-loop registration control system for an absorbent article manufacturing line, said control system comprising: means for feeding a continuous web of absorbent articles along a path; a sensor for detecting at least one preselected feature of each of said absorbent articles and producing a detection signal when said preselected feature passes by said sensor; a cutter for cutting said absorbent articles, said cutter located after said sensor and disposed in a cutter position relative to said preselected feature; means for determining the cutter position at the moment when said preselected feature is detected; means for calculating the average of a predetermined number of said cutter positions corresponding to a number of consecutive said absorbent articles which have passed by said sensor for detecting said at least one preselected feature; means for subtracting a predetermined target cutter position from said average cutter position so as to produce an error signal; and means for converting said error signal into a control signal and supplying said control signal to phase modifying means for said cutter; wherein said means for modifying the phase of said cutter modifies said cutter position in response to said control signal.

Claim 2

Dependent Claim 194 words

An improved closed-loop registration control system for an absorbent article manufacturing line, said control system comprising: means for feeding a continuous web of absorbent articles along a path; a sensor for detecting at least one preselected feature of each of said absorbent articles and producing a detection signal when said preselected feature passes by said sensor; a cutter for cutting said absorbent articles, said cutter located after said sensor and disposed in a cutter position relative to said preselected feature; means for determining the cutter position at the moment when said preselected feature is detected; means for calculating the average of a predetermined number of said cutter positions corresponding to a number of consecutive said absorbent articles which have passed by said sensor for detecting said at least one preselected feature; means for subtracting a predetermined target cutter position from said average cutter position so as to produce an error signal; and means for converting said error signal into a control signal and supplying said control signal to phase modifying means for said cutter; wherein said means for modifying the phase of said cutter modifies said cutter position in response to said control signal.

Claim 3

Dependent Claim 25 words

The control system of claim 1 wherein said means for modifying the phase of said cutter modifies said cutter position proportionally to said control signal.

Claim 4

Dependent Claim 13 words

The control system of claim 2 wherein said sensor comprises an optical scanner.

Claim 5

Dependent Claim 19 words

The control system of claim 1 wherein said means for feeding comprises at least one set of pull rolls.

Claim 6

Dependent Claim 26 words

The control system of claim 4 wherein said means for feeding comprises two sets of pull rolls and said sensor is positioned between said pull rolls.

Claim 7

Dependent Claim 18 words

The control system of claim 1 wherein said means for determining said cutter position comprises a position resolver.

Claim 8

Dependent Claim 22 words

The control system of claim 1 wherein said means for modifying the phase comprises a velocity controlled servo and a phase variator.

Claim 9

Dependent Claim 38 words

The registration control system of claim 1 wherein said means for feeding a continuous web of absorbent articles moves at a predetermined speed, said cutter position being maintained relative to said preselected feature independently of said predetermined speed.

Claim 10

Dependent Claim 18 words

The control system of claim 1, wherein said preselected feature is a functional feature of said absorbent articles.

Claim 11

Dependent Claim 19 words

The control system of claim 9 wherein said preselected functional feature of said absorbent article comprises a fastening tab.

Claim 12

Dependent Claim 25 words

The control system of claim 9 wherein said preselected functional feature of said absorbent article comprises the edge of the core of said absobent article.

Claim 13

Dependent Claim 182 words

An improved method for controlling an angular position of a knife in manufacturing an absorbent article pad from a moving continuous web of absorbent article pads, said method comprising the steps of: establishing a target knife position for cutting said absorbent article pad; detecting at least one preselected feature of said absorbent article pad and producing a detection signal as said preselected feature is detected by a detection means; determining said angular position of said knife when said preselected feature is detected; storing said angular position of said knife; comparing said angular position of said knife to said target knife position; calculating an average knife position from a predetermined number of stored angular positions of said knife to a corresponding number of consecutive absorbent article pads which have been detected by said detection means; subtracting said target knife position from said average knife position to produce an error signal; converting said error signal into a control signal and supplying said control signal to a knife position modifying means; and modifying said angular position of said knife in response to said control signal.

Claim 14

Dependent Claim 182 words

An improved method for controlling an angular position of a knife in manufacturing an absorbent article pad from a moving continuous web of absorbent article pads, said method comprising the steps of: establishing a target knife position for cutting said absorbent article pad; detecting at least one preselected feature of said absorbent article pad and producing a detection signal as said preselected feature is detected by a detection means; determining said angular position of said knife when said preselected feature is detected; storing said angular position of said knife; comparing said angular position of said knife to said target knife position; calculating an average knife position from a predetermined number of stored angular positions of said knife to a corresponding number of consecutive absorbent article pads which have been detected by said detection means; subtracting said target knife position from said average knife position to produce an error signal; converting said error signal into a control signal and supplying said control signal to a knife position modifying means; and modifying said angular position of said knife in response to said control signal.

Claim 15

Dependent Claim 24 words

The method of claim 12 further comprising the step of moving said continuous web of absorbent article pads with respect to said detection means.

Claim 16

Dependent Claim 60 words

The method of claim 12 wherein said detecting step further comprises the steps of: emitting a light beam by said detection means upon said web; detecting a change in said light beam caused by said preselected feature of said absorbent article pad as said preselected feature moves relative to said detection means; and sensing said change in said light beam.

Claim 17

Dependent Claim 29 words

The method of claim 12 wherein said step of modifying said angular position of said knife further comprises the step of driving a phase variator connected to said knife.

Claim 18

Dependent Claim 20 words

The method of claim 12 wherein said average knife position is calculated from at least five consecutive absorbent article pads.

Claim 19

Dependent Claim 25 words

The method of claim 12 further comprising the step of determining whether said angular position of said knife is inside or outside a predetermined range.

Claim 20

Dependent Claim 36 words

The method of claim 17 wherein if said angular position of said knife is outside said predetermined range, said average is used as the next angular position of said knife in calculating said average knife position.

Claim 21

Dependent Claim 30 words

The method of claim 18 wherein, after start-up no change in said angular position of said knife is made until a predetermined number of said preselected features have been detected.

Claim 22

Dependent Claim 162 words

An improved closed-loop registration control system for controlling the placement of a cut with respect to a preselected feature of an individual absorbent article pad along a continuous web of absorbent article pads, said control system comprising: at least one pull roll for advancing said continuous web along an absorbent article line; a knife for performing said cut; a scanner positioned along said absorbent article line at a location juxtaposed with said knife; said scanner for detecting and producing a detection signal as said preselected feature passes by said scanner; a position resolver connected to said knife for determining the angular position of said knife when said preselected feature is detected; means for subtracting a preselected target knife position from an average knife position, thereby producing an error signal; a proportional compensator for converting said error signal into a control signal; and a servo, which in response to said control signal, drives a phase variator to correct the placement of said cut.

Claim 23

Dependent Claim 162 words

An improved closed-loop registration control system for controlling the placement of a cut with respect to a preselected feature of an individual absorbent article pad along a continuous web of absorbent article pads, said control system comprising: at least one pull roll for advancing said continuous web along an absorbent article line; a knife for performing said cut; a scanner positioned along said absorbent article line at a location juxtaposed with said knife; said scanner for detecting and producing a detection signal as said preselected feature passes by said scanner; a position resolver connected to said knife for determining the angular position of said knife when said preselected feature is detected; means for subtracting a preselected target knife position from an average knife position, thereby producing an error signal; a proportional compensator for converting said error signal into a control signal; and a servo, which in response to said control signal, drives a phase variator to correct the placement of said cut.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2000-08-18	2001-02-17	2001-08-19	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2004-08-18	2005-02-17	2005-08-19	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2008-08-18	2009-02-17	2009-08-19	$7700.00	Window Closed / Lapsed

Diaper registration control system

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