Twisted cable

Abstract

A twisted cable includes a main body which includes a central filament and a plurality of twisted filaments. The twisted filaments are arranged around the central filament and include six first filaments, twelve second filaments, and eighteen third filaments from the central filament outward. The cross-section of each first filament is the same with the one of each second filament. The cross-section of each first filament is larger than the one of the third filament but smaller than the one of the central filament. The twisted filaments are twisted around the central filament. As a result, the twisted cable of the present invention has improved structure strength, appropriate toughness, and smaller amount of longitudinal deformation.

What is claimed is: 
     
         1 . A twisted cable, including a main body, the main body including a central filament and a plurality of twisted filaments, the twisted filaments being arranged around the central filament, the twisted filaments being classified into an inner layer, an intermediate layer, and an outer layer which are arranged outward;
 wherein the twisted filaments includes first filaments, second filaments, and third filaments, cross-section area of each first filament is same with cross-section area of each second filament, cross-section area of each third filament is smaller than the cross-section area of each first filament, the cross-section areas of each first filament, each second filament, and each third filament are smaller than cross-section area of the central filament respectively, the inner layer includes six first filaments, the intermediate layer includes twelve second filaments, the outer layer includes eighteen third filaments, the twisted filaments are twisted around the central filament.   
     
     
         2 . The twisted cable of  claim 1 , wherein the central filament, each first filament, one of the second filaments, and one of the third filaments are aligned in a cross-section of the twisted cable. 
     
     
         3 . The twisted cable of  claim 1 , wherein the cross-section of the central filament and the cross-section of each twisted cable are circles. 
     
     
         4 . The twisted cable of  claim 3 , wherein ratio of diameter of the central filament, each first filament, each second filament, and each third filament is 23:22:22:21. 
     
     
         5 . The twisted cable of  claim 1 , wherein the central filament and each twisted filament are made of metal.