Electrically conductive yarn

Abstract

A yarn that is electrically conductive, that can be elongated considerably, at least briefly, without loss of conductivity, and that exhibits improved elongation properties.

1 . An electrically conductive yarn comprising: 
 at least one elastic core thread;    at least one electrically conductive thread that is wound around the core thread; and    at least one binding thread that is wound around the core thread, wherein the extensibility of the entire electrically conductive yarn is restricted by the binding thread.    
   
   
       2 . The electrically conductive yarn according to  claim 1 , wherein above a certain tensile load, the binding thread effects a disproportionate rise in the restoring force of the electrically conductive yarn, said disproportionate rise in the restoring force occurring prior to the loss of the conductivity of the yarn.  
   
   
       3 . The electrically conductive yarn according to  claim 1  wherein the core thread is composed of a rubber elastic material.  
   
   
       4 . The electrically conductive yarn according to  claim 1  wherein the elastic core thread exhibits an elongation at break of at least 50%.  
   
   
       5 . The electrically conductive yarn according to claims  1  or  2 , in which the rubber elastic core thread is selected from the group consisting of natural rubber, synthetic rubber, polyester elastane, polyether elastane, modified polyester, post-cross-linked thermoplast, polyester-polyurethane elastomer, and polyether-polyurethane elastomer.  
   
   
       6 . The electrically conductive yarn according to  claim 1  where the yarn exhibits a maximum permanent elongation of no more than about 5% without loss of electrical conductivity after elastic elongation by at least 15% in the lengthwise direction.  
   
   
       7 . The electrically conductive yarn according to  claim 1 , wherein the electrically conductive thread comprises a monofilament metal wire with a diameter between about 0.01 and 0.1 mm.  
   
   
       8 . The electrically conductive yarn according to  claim 1  wherein the electrically conductive thread comprises a metallic-coated synthetic fiber.  
   
   
       9 . The electrically conductive yarn according to  claim 1  wherein the electrically conductive thread comprises monofilament silver-coated fibers.  
   
   
       10 . The electrically conductive yarn according to  claim 1  wherein the electrically conductive thread comprises a metallic multifilament yarn.  
   
   
       11 . The electrically conductive yarn according to  claim 1  wherein the electrically conductive thread comprises a silver-coated multifilament yarn.  
   
   
       12 . The electrically conductive yarn according to  claim 1  wherein the electrically conductive thread comprises stainless steel fibers.  
   
   
       13 . The electrically conductive yarn according to  claim 1  wherein the binding thread is wound around outside the core thread, said core thread being enwound with the electrically conductive thread.  
   
   
       14 . The electrically conductive yarn according to  claim 1  wherein the electrically conductive thread is wound around outside the core thread, said core thread being enwound with the binding thread.  
   
   
       15 . The electrically conductive yarn according to  claim 1  in which the electrically conductive thread is wrapped around the elastic core thread at least about 1,000 times per meter of yarn.  
   
   
       16 . The electrically conductive yarn according to  claim 1  in which the binding thread is wrapped around the elastic core thread at least about 1,000 times per meter of yarn.  
   
   
       17 . The electrically conductive yarn according to  claim 1  wherein the electrically conductive thread and the binding thread are wrapped around the elastic core thread in opposite directions.  
   
   
       18 . A method for manufacturing an electrically conductive yarn comprising the steps of: 
 mechanically drawing the elastic core thread on drawing equipment;    passing the drawn core thread through a hollow spindle bearing the electrically conductive thread and rotating around its longitudinal axis; and    passing the drawn core thread, already singly enwound with an electrically conductive thread, through a second hollow spindle bearing a binding thread and rotating around its longitudinal axis, said second hollow spindle rotating counter to the first hollow spindle.    
   
   
       19 . A fabric comprising at least one electrically conductive yarn, said yarn comprising at least one elastic core thread, at least one electrically conductive thread that is wound around the core thread, and at least one binding thread that is wound around the core thread, wherein the extensibility of the entire electrically conductive yarn is restricted by the binding thread.  
   
   
       20 . A method for transmitting an electrical signal comprising: 
 providing an electrically conductive yarn comprising at least one elastic core thread, at least one electrically conductive thread that is wound around the core thread, and at least one binding thread that is wound around the core thread, wherein the extensibility of the entire electrically conductive yarn is restricted by the binding thread;    providing an electrical signal source;    coupling the yarn to the signal source; and    transmitting the electrical signal.    
   
   
       21 . The method of  claim 20  wherein the the electrical signal is selected from the group consisting of an analog signal, a digital signal, and both an analog and a digital signal.  
   
   
       22 . A method for supplying electrical power to an electronic device comprising: 
 providing an electrically conductive yarn comprising at least one elastic core thread, at least one electrically conductive thread that is wound around the core thread, and at least one binding thread that is wound around the core thread, wherein the extensibility of the entire electrically conductive yarn is restricted by the binding thread;    providing an electrical power source;    coupling the yarn to the power source and the electronic device; and    transmitting electrical power from the power source to the electronic unit through the yarn.    
   
   
       23 . A method for generating heat by means of electric current, said method comprising: 
 providing an electrically conductive yarn comprising at least one elastic core thread, at least one electrically conductive thread that is wound around the core thread, and at least one binding thread that is wound around the core thread, wherein the extensibility of the entire electrically conductive yarn is restricted by the binding thread;    providing an electrical power source;    coupling the yarn to the power source; and    transmitting electrical power from the power source through the yarn whereby generating heat.    
   
   
       24 . A method for shielding electromagnetic fields comprising the step of providing an electrically conductive yarn, said yarn comprising at least one elastic core thread, at least one electrically conductive thread that is wound around the core thread, and at least one binding thread that is wound around the core thread, wherein the extensibility of the entire electrically conductive yarn is restricted by the binding thread.  
   
   
       25 . A method for dissipating static charges comprising the step of providing an electrically conductive yarn, said yarn comprising at least one elastic core thread, at least one electrically conductive thread that is wound around the core thread, and at least one binding thread that is wound around the core thread, wherein the extensibility of the entire electrically conductive yarn is restricted by the binding thread.  
   
   
       26 . A humidity sensor comprising an electrically conductive yarn, said yarn comprising at least one elastic core thread, at least one electrically conductive thread that is wound around the core thread, and at least one binding thread that is wound around the core thread, wherein the extensibility of the entire electrically conductive yarn is restricted by the binding thread.  
   
   
       27 . A strain sensor comprising an electrically conductive yarn, said yarn comprising at least one elastic core thread, at least one electrically conductive thread that is wound around the core thread, and at least one binding thread that is wound around the core thread, wherein the extensibility of the entire electrically conductive yarn is restricted by the binding thread.