Electrical Cable

Abstract

An electrical cable includes a first conductor assembly having a first inner conductor and a first insulator engaging and surrounding a surface of the first inner conductor and a second conductor assembly having a second inner conductor and a second insulator engaging and surrounding a surface of the second inner conductor. The electrical cable includes a non-conductive buffer layer surrounding the conductor assemblies having an inner surface engaging the insulators and a conductive shield layer engaging and surrounding an outer surface of the non-conductive buffer layer and providing electrical shielding for the conductor assemblies. An outer jacket engages and surrounds the conductive shield layer.

What is claimed is: 
     
         1 . An electrical cable comprising:
 a first conductor assembly that extends along a length of the electrical cable, the first conductor assembly comprising a first inner conductor and a first insulator engaging and surrounding a surface of the first inner conductor;   a second conductor assembly adjacent the first conductor assembly along the length of the electrical cable, the second conductor assembly comprising a second inner conductor and a second insulator engaging and surrounding a surface of the second inner conductor;   a non-conductive buffer layer surrounding the first and second conductor assemblies, the non-conductive buffer layer having an inner surface engaging the first and second insulators and an outer surface opposite the inner surface;   a conductive shield layer engaging and surrounding the outer surface of the non-conductive buffer layer, the shield layer providing electrical shielding for the first and second conductor assemblies; and   an outer jacket engaging and surrounding the conductive shield layer.   
     
     
         2 . The electrical cable of  claim 1 , wherein the non-conductive buffer layer comprises braided strands of non-conductive material. 
     
     
         3 . The electrical cable of  claim 2 , wherein the conductive shield layer comprises braided strands of conductive material. 
     
     
         4 . The electrical cable of  claim 3 , wherein the non-conductive buffer layer has M number of picks of braided strands of non-conductive material and the conductive shield layer has N number of picks of braided strands of conductive material different than the M number of picks of braided strands of non-conductive material. 
     
     
         5 . The electrical cable of  claim 1 , wherein the first and second conductor assemblies are electrically connected to a camera at a first end of the electrical cable and the first and second conductor assemblies are electrically connected to a camera control unit at a second end of the electrical cable. 
     
     
         6 . The electrical cable of  claim 1 , wherein the shield layer has a uniform radial thickness around the outer perimeters of the first and second insulators. 
     
     
         7 . The electrical cable of  claim 1 , wherein the non-conductive buffer layer has a uniform thickness between the inner surface and the outer surface to locate the conductive shield layer at a uniform distance from the first and second conductor assemblies. 
     
     
         8 . The electrical cable of  claim 1 , wherein the non-conductive buffer layer comprises braided strands of aromatic polymer material. 
     
     
         9 . The electrical cable of  claim 1 , wherein the non-conductive buffer layer is porous to air. 
     
     
         10 . The electrical cable of  claim 1 , wherein the non-conductive buffer layer has greater flexibility per thickness than the material of the first and second insulators. 
     
     
         11 . The electrical cable of  claim 1 , wherein the non-conductive buffer layer has increased pull strength compared to the material of the first and second insulators. 
     
     
         12 . The electrical cable of  claim 1 , wherein the non-conductive buffer layer is braided around the first and second conductor assemblies. 
     
     
         13 . The electrical cable of  claim 1 , wherein the first and second conductor assemblies are twisted helically around each other along the length of the electrical cable. 
     
     
         14 . The electrical cable of  claim 1 , wherein the inner surface engages the first insulator along a minority of a circumference of the first insulator and the inner surface engages the second insulator along a minority of a circumference of the second insulator. 
     
     
         15 . The electrical cable of  claim 1 , further comprising a third conductor assembly that extends along the length of the electrical cable, the third conductor assembly comprising a third inner conductor and a third insulator engaging and surrounding a surface of the third inner conductor, and further comprising a fourth conductor assembly that extends along the length of the electrical cable, the fourth conductor assembly comprising a fourth inner conductor and a fourth insulator engaging and surrounding a surface of the fourth inner conductor, the first and second conductor assemblies defining a first twisted pair, the third and fourth conductor assemblies defining a second twisted pair, the non-conductive buffer layer surrounding the third and fourth conductor assemblies such that the inner surface engages the third and fourth insulators, the conductive shield layer providing electrical shielding for the third and fourth conductor assemblies. 
     
     
         16 . An electrical cable comprising:
 a first conductor assembly that extends along a length of the electrical cable, the first conductor assembly comprising a first inner conductor and a first insulator engaging and surrounding a surface of the first inner conductor;   a second conductor assembly adjacent the first conductor assembly along the length of the electrical cable, the second conductor assembly comprising a second inner conductor and a second insulator engaging and surrounding a surface of the second inner conductor;   a non-conductive buffer layer surrounding the first and second conductor assemblies, the non-conductive buffer layer comprising braided strands of non-conductive material, the non-conductive buffer layer having an inner surface engaging the first and second insulators and an outer surface opposite the inner surface;   a conductive shield layer engaging and surrounding the outer surface of the non-conductive buffer layer, the conductive shield layer comprising braided strands of conductive material, the shield layer providing electrical shielding for the first and second conductor assemblies; and   an outer jacket engaging and surrounding the conductive shield layer.   
     
     
         17 . The electrical cable of  claim 16 , wherein the non-conductive buffer layer comprises braided strands of aromatic polymer material. 
     
     
         18 . An electrical cable for a video endoscope device having a camera and a display, the electrical cable comprising:
 a first conductor assembly that extends along a length of the electrical cable configured to be electrically connected to the camera and the display, the first conductor assembly comprising a first inner conductor and a first insulator engaging and surrounding a surface of the first inner conductor;   a second conductor assembly adjacent the first conductor assembly along the length of the electrical cable configured to be electrically connected to the camera and the display, the second conductor assembly comprising a second inner conductor and a second insulator engaging and surrounding a surface of the second inner conductor;   a non-conductive buffer layer surrounding the first and second conductor assemblies, the non-conductive buffer layer having an inner surface engaging the first and second insulators and an outer surface opposite the inner surface;   a conductive shield layer engaging and surrounding the outer surface of the non-conductive buffer layer, the shield layer providing electrical shielding for the first and second conductor assemblies; and   an outer jacket engaging and surrounding the conductive shield layer.