Carpet position sensor
First Claim
1. In a carpet making machine of the type in which generally opaque tufts of carpet pile are affixed to an open weave, somewhat transparent primary backing material in an offset row pattern to cause said pile tufts to form a longitudinally extending, undulating pile tuft edge approaching and receding from the longitudinally extending side width edges of a carpet defined by said primary backing material, the improvement comprising:
- a) a first plurality of light sources spaced from one side of said carpet, said plurality of light sources extending, on a line at spaced increments from one width edge of said carpet towards the center of said carpet;
b) a first plurality of signal generating light sensors positioned on the opposite side of said carpet extending on a line and aligned with said first plurality of light sources so that each light sensor can sense any light passing from an aligned light source through said primary backing material while light is blocked by said opaque tufts;
c) a signal processor including a clock for sequentially actuating each light source and a corresponding sensor in registry with an actuated light sensor in a scan regularly repeated while said carpet travels past said sources and sensors, said signal processor determining from a set light attenuation level sensed by said sensors the average position of said undulating pile tuft edge as said carpet passes between said light sources and said light sensors; and
ad) centering mechanism responsive to said signal processor for maintaining said carpet centered within said carpet making machine by the average position of the pile tuft edge.
11 Assignments
0 Petitions
Accused Products
Abstract
A position detector senses an undulating pile tuft edge position of a carpet as it is processed in a carpet making machine by detecting attenuated light passing through the carpet'"'"'s primary backing material to determine the exact position of the carpet'"'"'s undulating pile tuft edge at any given time. Sensor signals from the detector are digitally filtered through one pole cascaded filters to produce an average pile edge position signal which, in turn, controls actuators for secondary and primary backing material guide rolls to not only center the carpet for aligned entry into the carpet machine'"'"'s tenter, but also apply the secondary backing material to the primary backing material at a precise position.
41 Citations
41 Claims
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1. In a carpet making machine of the type in which generally opaque tufts of carpet pile are affixed to an open weave, somewhat transparent primary backing material in an offset row pattern to cause said pile tufts to form a longitudinally extending, undulating pile tuft edge approaching and receding from the longitudinally extending side width edges of a carpet defined by said primary backing material, the improvement comprising:
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a) a first plurality of light sources spaced from one side of said carpet, said plurality of light sources extending, on a line at spaced increments from one width edge of said carpet towards the center of said carpet; b) a first plurality of signal generating light sensors positioned on the opposite side of said carpet extending on a line and aligned with said first plurality of light sources so that each light sensor can sense any light passing from an aligned light source through said primary backing material while light is blocked by said opaque tufts; c) a signal processor including a clock for sequentially actuating each light source and a corresponding sensor in registry with an actuated light sensor in a scan regularly repeated while said carpet travels past said sources and sensors, said signal processor determining from a set light attenuation level sensed by said sensors the average position of said undulating pile tuft edge as said carpet passes between said light sources and said light sensors; and
ad) centering mechanism responsive to said signal processor for maintaining said carpet centered within said carpet making machine by the average position of the pile tuft edge.
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2. In a carpet making machine of the type in which generally opaque tufts of carpet pile are affixed to an open weave, generally transparent primary backing material in an offset row pattern to cause said pile tufts to form a longitudinally extending, undulating pile tuft edge approaching and receding from the longitudinally extending side width edges of a carpet defined by said primary backing material, the improvement comprising:
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a) a first plurality of light sources spaced from one side of said carpet, said plurality of light sources extending, at spaced increments from one width edge of said carpet towards the center of said carpet; b) a first plurality of signal generating light sensors positioned on the opposite side of said carpet and aligned with said first plurality of light sources so that each light sensor can sense any light passing from an aligned light source through said primary backing material while light is blocked by said opaque tufts; c) signal processing means effective when said light sources are activated to determine from said light sensor signals the average position of said undulating pile tuft edge as said carpet passes between said light sources and said light sensors;
said signal processing means includes clock means for sequentially actuating each light source in said plurality of light sources during any given periodic scan to produce a corresponding sequence of light sensor signals and comparator means comparing each light sensor signal to a threshold light attenuation level to determine, for each scan, the average position of said pile tuft edge andd) centering means responsive to signal processing means for maintaining said carpet centered within said carpet making machine. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A detector especially suited for detecting edge positions of fabric as it is processed through a fabric making machine, said fabric having varying degrees of transparencies at its width ends, said detector comprising:
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a) a first plurality of light sources extending along a line from outside the fabric width edge towards the center of the fabric, said light sources positioned on one side of said fabric; b) a plurality of light sensors on the opposite side of the fabric with each sensor aligned with a corresponding light source, said light sensors emitting analog sensor signals when receiving light from said light sources; c) clock circuit means for sequentially actuating each light source in said first plurality of light sources at a given scan frequency; d) means to compare each of said sensor signals with a set threshold signal indicative of a set light intensity and generate a position signal when any sensor signal exceeds said threshold signal; e) means to count said position signals to determine a distance correlated to a position on said fabric whereat said fabric permits light of a set intensity to pass therethrough; and
,f) means to filter each signal to produce a filtered position signal indicative of a width end position of said fabric. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35)
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36. A process for making carpet in which tufts of carpet pile are applied to a generally transparent primary backing material in offset rows to produce at the width edges of the carpet undulating waves of pile tufts approaching and receding from the width edges of the primary backing material which defines the carpet width edge, said process comprising the steps of:
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a) conveying by guide rolls said primary backing material with carpet pile affixed thereto to a position adjacent a tenter; b) conveying a generally transparent secondary backing material from a pay out reel through at least one adhesive tank by guide rolls into an aligned position, underlying and contacting said primary backing material to form a composite backing adjacent said tenter; c) providing upstream of said tenter and upstream of the position whereat said secondary backing material contacts said primary backing material, on one side of said primary backing material a plurality of LEDs on a line extending from a point beyond the width edge of said primary backing material towards the center of said carpet and on the opposite side of said primary backing material a plurality of photo transistors aligned with said plurality of LEDs; d) generating a plurality of centering signals, each indicative of the average tuft pile width position as said carpet travels past said plurality of LEDs and photo transistors by i) sequentially activating said LEDs during a scan, each scan conducted at a set frequency to produce a sequenced plurality of light sensor signals from said photo transistors, said photo transistors set to distinguish attenuated light passing through said primary backing material; ii) determining in each scan the number of photo transistor signals which exceeded a set attenuated light threshold value and generating a position signal in response to that determination; and iii) filtering said position signal to produce for each scan a centering signal; e) adjusting said secondary backing material guide rolls by said centering signal to achieve centered alignment of said secondary backing material with said average tuft pile width positions; and f) transferring said composite backing onto the pins of said tenter for precisely stretching said composite material, drying said adhesive and trimming said carpet width edges to commercial carpet width sizes. - View Dependent Claims (37)
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38. A moving web edge detector comprising
a) a first plurality of light sources extending along a line from outside the web towards the center of the web, said light sources positioned on one side of the web; -
b) a second plurality of light sensors extending along a line on the opposite side of the web, each sensor generally aligned with a corresponding light source; c) a clock circuit for sequentially actuating each light source in the first plurality and sequentially enabling an aligned sense to sense the light emitted from an actuated light source in a periodically affected scan; and
,d) a CPU signal processor evaluating the light intensity sensed by the sensors in each scan to determine the location of the web edge from the position and/or number of sensors actuated when light intensities at or above a set intensity has been detected. - View Dependent Claims (39, 40, 41)
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Specification