Pull cord for coverings for architectural openings and method of making same

Abstract

A method of manufacturing a control cord for use in a covering for architectural openings includes the steps of providing spools of high tensile strength and low abrasion characteristic yarns, tensioning the yarns and winding the yarns under tension on bobbins, placing the bobbins in a braiding apparatus and making an eight-carrier braid from the yarns on the bobbins, and passing the braided cord through a treatment apparatus where a urethane coating is applied to the yarns and heat cured.

1 . A covering for an architectural opening comprising in combination: 
 covering means for selectively covering and uncovering the architectural opening by extension and retraction of said covering means; and    an operating mechanism mounted adjacent to said architectural opening and being operatively associated with said covering means, said mechanism including a control cord and operative elements frictionally engaged with said control cord, said control cord being made from yarn having a tensile strength in the range of 28-35 grams/denier and a denier in the range of 275-375.    
     
     
         2 . The covering of  claim 1  wherein said yarn is made of polyethylene.  
     
     
         3 . The covering of  claim 1  or  2  wherein said cord is made from said yarn that is braided.  
     
     
         4 . The covering of  claim 3  wherein said yarn is wound on bobbins under a tension of 115-140 grams prior to being braided into said cord.  
     
     
         5 . The covering of  claim 3  or  4  wherein said braided cord is placed under tension of 150-200 grams and coated with urethane prior to being incorporated into said operating mechanism.  
     
     
         6 . The covering of  claim 5  wherein said braided cord is coated with a mixture of urethane and water, then dried and cured prior to being incorporated into said operating mechanism.  
     
     
         7 . The covering of  claim 6  wherein said urethane is a polyester, polyether urethane.  
     
     
         8 . The covering of  claim 5 , wherein said urethane is a polyester, polyether urethane.