Twelve-strand rope employing jacketed sub-ropes

Abstract

A rope structure is formed by forming a sub-rope structure comprising a core and a jacket, twisting the sub-rope structure to form a twisted sub-rope structure, and forming the rope structure by braiding together a plurality of lengths of the twisted sub-rope structure.

What is claimed is: 
     
         1 . A method of forming a rope structure comprising the steps of:
 forming a sub-rope structure comprising a core and a jacket;   twisting the sub-rope structure to form a twisted sub-rope structure;   forming the rope structure by braiding together a plurality of lengths of the twisted sub-rope structure.   
     
     
         2 . A method as recited in  claim 1 , further comprising the steps of:
 forming strands from filaments; and   combining lengths of the strands to form the core and the jacket of the sub-rope structure.   
     
     
         3 . A method as recited in  claim 2 , in which:
 the step of combining the strands to form the core comprises the step of braiding together twelve lengths of the strands; and   the step of combining the strands to form the jacket comprises the step of braiding together twelve lengths of the strands around the core.   
     
     
         4 . A method as recited in  claim 1 , in which the step of twisting the sub-rope structure to form the twisted sub-rope structure further comprises the steps of:
 determining an amount of braid twist applied when the lengths of twisted sub-rope structures are braided together to form the rope structure; and   applying sufficient pre-twist when forming the twisted sub-rope structure to compensate for the braid twist.   
     
     
         5 . A method as recited in  claim 1 , further comprising the step of arranging a filter member between the core and the jacket. 
     
     
         6 . A method as recited in  claim 1 , in which the step of forming the rope structure comprises the step of braiding together twelve of lengths of the twisted sub-rope structure. 
     
     
         7 . A rope structure comprising a plurality of lengths of a sub-rope structure comprising a core and a jacket, where a reference line substantially parallel to a longitudinal axis of the sub-rope structure when the rope sub-structure is initially formed is substantially parallel to the longitudinal axis of the rope sub-structure when the plurality of lengths of the sub-rope structure are braided together to form the rope structure. 
     
     
         8 . A rope structure as recited in  claim 7 , in which:
 lengths of strands are braided together to form the core and the jacket of the sub-rope structure; and   the strands comprise filaments.   
     
     
         9 . A rope structure as recited in  claim 8 , in which:
 the core of the rope sub-structure comprises twelve lengths of the strands; and   the jacket of the rope sub-structure comprises twelve lengths of the strands.   
     
     
         10 . A rope structure as recited in  claim 8 , further comprising a filter member between the core and the jacket. 
     
     
         11 . A rope structure as recited in  claim 8 , in which the rope structure comprises twelve of lengths of the sub-rope structure. 
     
     
         12 . A method of forming a rope structure comprising the steps of:
 providing a rope sub-structure comprising a core and a jacket;   determining an amount of braid twist obtained when braiding the rope sub-structure to form the rope structure; and   forming a twisted sub-rope structure by pre-twisting the sub-rope structure to compensate for the braid twist;   braiding lengths of the twisted sub-rope structure together to form the rope structure.   
     
     
         13 . A method as recited in  claim 12 , further comprising the steps of:
 forming strands from filaments; and   combining lengths of the strands to form the core and the jacket of the sub-rope structure.   
     
     
         14 . A method as recited in  claim 13 , in which:
 the step of combining the strands to form the core comprises the step of braiding together twelve lengths of the strands; and   the step of combining the strands to form the jacket comprises the step of braiding together twelve lengths of the strands around the core.   
     
     
         15 . A method as recited in  claim 13 , further comprising the step of arranging a filter member between the core and the jacket. 
     
     
         16 . A method as recited in  claim 13 , in which the step of forming the rope structure comprises the step of braiding together twelve of lengths of the twisted sub-rope structure.