Methods for sensing features on moving fastener tape during automated production

Abstract

A method of manufacture comprising the following steps: (a) during a respective indexing portion of a respective work cycle, advancing a fastener tape made of flexible thermoplastic material along a process pathway, the fastener tape not advancing during a respective dwell time of the respective work cycle; (b) during each dwell time, forming or attaching a respective structural feature of a type on the portion of the fastener tape that is resident at a first fixed station situated along the process pathway, the structural features of that type being spaced at intervals along the portion of the fastener tape that is downstream of the first fixed station; (c) while the fastener tape is advancing along the process pathway during the indexing portion of each work cycle, transmitting light toward a volume of space at a second fixed station, the process pathway intersecting and passing through the volume of space; and (d) photodetecting at least portions of the transmitted light after some or all of the transmitted light has entered and then exited the volume of space at the second fixed station, the photodetected portions of the transmitted light being converted into electrical signals.

1 - 20 . (canceled)  
     
     
         21 : A system comprising a fastener processing machine, a fastener tape comprising mutually interlocked first and second zipper strips made of flexible material that follow a process pathway through said fastener processing machine, and a controller for controlling the operation of said fastener processing machine, wherein: 
 said fastener processing machine comprises a supply reel having a portion of said fastener tape wound thereon with a paid-out portion of said fastener tape connected thereto, a device for attaching or forming a respective structural feature of a type on the section of the paid-out portion of said fastener tape that is resident in a fixed zone along said process pathway, means for advancing the section that is resident in said fixed zone along said process pathway, and an optical sensor that detects a boundary of each passing structural feature of said type as said fastener tape is advanced along said process pathway; and    said controller is programmed to control the operation of said device and said fastener tape advancing means so that during an advancement phase of each work cycle, said fastener tape advancing means advances said fastener tape; and during a dwell time of each work cycle, said device is activated, and is further programmed to adjust the distance that said fastener tape advancing means advances said fastener tape during a particular work cycle in accordance with an algorithm that takes into account characteristics of electrical signals output by said optical sensor during work cycles preceding said particular work cycle.    
     
     
         22 : The system as recited in  claim 21 , wherein said device comprises a slider inserter.  
     
     
         23 : The system as recited in  claim 21 , wherein said device comprises an ultrasonic welding assembly.  
     
     
         24 : The system as recited in  claim 21 , wherein said optical sensor comprises a light-emitting diode and a photodetector.  
     
     
         25 : The system as recited in  claim 24 , further comprising a first optical fiber optically coupled to said light-emitting diode and a second optical fiber optically coupled to said photodetector.  
     
     
         26 : The system as recited in  claim 21 , wherein said optical sensor comprises a laser scanning transmitter and a laser scanning receiver.  
     
     
         27 : The system as recited in  claim 26 , wherein said controller is programmed to compute a change in the heights of respective gaps in a curtain of laser beams transmitted by said laser scanning transmitter and received by said laser scanning receiver at respective times.  
     
     
         28 : The system as recited in  claim 21 , wherein said optical sensor comprises a laser and a multi-element detector array.  
     
     
         29 : The system as recited in  claim 28 , wherein said optical sensor further comprises a transmitter lens and a receiver lens.  
     
     
         30 : A system comprising: 
 means for advancing a fastener tape made of flexible thermoplastic material along a process pathway during a respective indexing portion of a respective work cycle, said fastener tape not advancing during a respective dwell time of said respective work cycle;    means for deforming said fastener tape in a respective zone that is resident at a first fixed station situated along said process pathway during each dwell time, said deformed zones being spaced at intervals along the portion of said fastener tape that is downstream of said first fixed station;    means for transmitting light toward a volume of space at a second fixed station while said fastener tape is advancing along said process pathway during the indexing portion of each work cycle, said process pathway being arranged such that said deformed zones intersect and pass through said volume of space during advancement of said fastener tape;    means for photodetecting at least portions of said transmitted light after some or all of said transmitted light has entered and then exited said volume of space at said second fixed station, said photodetected portions of said transmitted light being converted into electrical signals that indicate a time when transmitted light impinges on an edge of a deformed zone as said deformed zone passes through said volume of space; and    a controller for controlling said advancing means as a function of electrical signals from said photodetecting means, said controller being programmed so that the distance that said fastener tape is advanced during an indexing portion of a particular work cycle is determined in accordance with an algorithm that takes into account characteristics of electrical signals from said photodetecting means acquired in during earlier work cycles.    
     
     
         31 : A system comprising: 
 means for advancing a fastener tape made of flexible transparent or translucent thermoplastic material along a process pathway during a respective indexing portion of a respective work cycle, said fastener tape not advancing during a respective dwell time of said respective work cycle;    a slider insertion device for inserting a respective slider on the portion of said fastener tape that is resident at a first fixed station situated along said process pathway during each dwell time, said sliders being spaced at intervals along the portion of said fastener tape that is downstream of said first fixed station, each slider being substantially opaque;    means for transmitting light toward a portion of said fastener tape in a volume of space at a second fixed station while said fastener tape is advancing along said process pathway during the indexing portion of each work cycle, respective portions of said sliders also passing through said volume of space;    means for photodetecting those portions of said transmitted light that pass through the portion of said fastener tape resident in said volume of space and that are not blocked by a slider, said photodetected portions of said transmitted light being converted into electrical signals that undergo a change in amplitude in response to a leading edge of said slider moving into the path of said transmitted light; and    a controller for controlling said advancing means as a function of electrical signals from said photodetecting means, said controller being programmed so that the distance that said fastener tape is advanced during an indexing portion of a particular work cycle is determined in accordance with an algorithm that takes into account characteristics of electrical signals from said photodetecting means acquired in during earlier work cycles.