Tubular Warp Knit Spacer Fabric

Abstract

A warp knitting system may knit a seamless tube of fabric. The fabric may have a spacer between outer and inner fabric layers. The knitting system may have first and second needle guide systems. The first and second needle guide systems may each have selectively linked needle bed sections that guide respective needles. A guide bar system may have guide bars that dispense strands of material during knitting. Each guide bar may be positioned using a respective guide bar positioner. The guide bar system may be shifted relative to the needles using a rotational positioner. The needle guide systems and guide bar system may be formed from selectively coupled links. The selectively coupled links may be configured to adjust the diameter of the tube of fabric to a desired value. The thickness of the tube may be adjusted by adjusting a gap between the first and second needle guide systems.

What is claimed is: 
     
         1 . A warp knitting system, comprising:
 a guide bar system having guide bars configured to dispense strands;   first and second needle beds separated by a gap;   a first needle guide system configured to guide the first needle bed to knit a first layer of fabric from the dispensed strands;   a second needle guide system configured to guide the second needle bed to knit a second layer of fabric from the dispensed strands; and   an adjustable positioner configured to adjust the gap between the first and second needle beds.   
     
     
         2 . The warp knitting system defined in  claim 1  further comprising:
 individually adjustable needle positioners each configured to adjust a position of a respective needle in the first and second needle beds. 
 
     
     
         3 . The warp knitting system defined in  claim 1  further comprising:
 individually adjustable guide bar positioners each of which is coupled to a respective one of the guide bars. 
 
     
     
         4 . The warp knitting system defined in  claim 3  wherein each of the guide bars has an eyelet that receives a respective one of the strands. 
     
     
         5 . The warp knitting system defined in  claim 1  further comprising a rotational positioner configured to shift the guide bar system relative to the first and second needle beds. 
     
     
         6 . The warp knitting system defined in  claim 1  further comprising a coupling structure that removably couples a first group of needles in the first needle bed to a second group of needles in the first needle bed. 
     
     
         7 . A warp knitting system operable to warp knit strands of material into a seamless tube of fabric, wherein the seamless tube of fabric has a spacer layer knit between an outer fabric layer and an inner fabric layer and has a thickness, the warp knitting system comprising:
 a guide bar system having guide bars each of which is configured to dispense a respective one of the strands;   a first needle guide system configured to guide a first set of needles to knit the inner fabric from the dispensed strands;   a second needle guide system configured to guide a second set of needles to knit the outer fabric layer from the dispensed strands; and   an adjustable positioner configured to adjust the thickness by adjusting a gap between the first and second sets of needle guide systems.   
     
     
         8 . The warp knitting system defined in  claim 7  wherein the adjustable positioner comprises an electrically adjustable positioner. 
     
     
         9 . The warp knitting system defined in  claim 8  wherein:
 the guide bar system has a plurality of selectively coupled guide bar links; 
 the first needle guide system is formed from a first set of selectively coupled needle bed links; and 
 the second needle guide system is formed from a second set of selectively coupled needle bed links. 
 
     
     
         10 . The warp knitting system defined in  claim 9  further comprising:
 needle positioners, wherein each of the needles is configured to be positioned by a respective one of the needle positioners; and 
 a controller configured to independently adjust each of the needle positioners and configured to adjust the electrically adjustable positioner. 
 
     
     
         11 . The warp knitting system defined in  claim 10  wherein the guide bar system includes electrically adjustable guide bar positioners coupled respectively to the guide bars and wherein the controller is configured to independently position each of the guide bars by independently controlling the electrically adjustable guide bar positioners. 
     
     
         12 . The warp knitting system defined in  claim 11  wherein the controller is configured to control the guide bar system and the needle positioners to selectively insert rows of stitches in the seamless tube of fabric to create a longitudinal bend in the seamless tube of fabric. 
     
     
         13 . The warp knitting system defined in  claim 11  wherein the controller is configured to control the guide bar system and needle positioners to adjust stitch tightness in selected portions of the seamless tube of fabric to create a cross-sectional profile for the seamless tube of fabric that includes bends. 
     
     
         14 . The warp knitting system defined in  claim 7  further comprising a take down system configured to receive the seamless tube of fabric through an opening in the second needle guide system. 
     
     
         15 . The warp knitting system defined in  claim 7  further comprising a rotational positioner configured to rotate the guide bar system relative to the first and second needle guide systems. 
     
     
         16 . A warp knitting system operable to warp knit strands of material into a seamless tube of fabric having a diameter, the warp knitting system comprising:
 a guide bar system having a plurality of selectively coupled guide bar sections configurable to adjust the diameter to a desired value, each guide bar section having guide bars that are each configured to dispense a respective one of the strands;   a first set of selectively coupled needle guide sections configurable to adjust the diameter to the desired value, wherein the first set of selectively coupled needle guide sections are configured to guide a first set of needles to knit the inner fabric from the dispensed strands; and   a second set of selectively coupled needle guide sections configurable to adjust the diameter to the desired value, wherein the second set of selectively coupled needle guide sections are configured to guide a second set of needles to knit the outer fabric layer from the dispensed strands.   
     
     
         17 . The warp knitting system defined in  claim 16  wherein the first set of selectively coupled needle guide sections includes a portion of a conical needle bed. 
     
     
         18 . The warp knitting system defined in  claim 17  wherein the first set of selectively coupled needle guide sections includes a non-conical needle bed. 
     
     
         19 . The warp knitting system defined in  claim 16  wherein the seamless tube of fabric has a spacer layer knit between an outer fabric layer and an inner fabric layer and has a thickness, the warp knitting system further comprising a component configured to adjust the thickness by adjusting a gap between the first and second sets of selectively coupled needle guide sections. 
     
     
         20 . The warp knitting system defined in  claim 19  further comprising:
 individually adjustable needle positioners each of which is coupled to a respective one of the needles; 
 individually adjustable guide bar positioners each of which is coupled to a respective one of the guide bars, wherein each of the guide bars has an eyelet that receives the respective one of the strands being dispensed by that guide bar; and 
 a rotational positioner configured to move the guide bars relative to the needles.