Communication cable for use in a plenum

Abstract

A communication cable includes a plurality of twisted pairs of electrical conductors, each electrical conductor being surrounded by a layer of plenum rated insulation. The cable also includes at least one additional twisted pair of electrical conductors, each electrical conductor thereof being surrounded by a layer of non-plenum rated insulation.

What is claimed is:  
     
       1. A communication cable for use in a plenum, said cable comprising: 
       a plurality of twisted pairs of electrical conductors, each electrical conductor of said plurality of twisted pairs having a single surrounding layer of electrical insulation, said single surrounding layer of electrical insulation of each electrical conductor of said plurality of twisted pairs being formed from a first material  fluoroethylenepropylene ( FEP );  
       at least one additional twisted pair of electrical conductor, each electrical conductor of said at least one additional twisted pair having a single surrounding layer of electrical insulation, said single surrounding layer of electrical insulation of each electrical conductor of said at least one additional twisted pair being formed from a second material, said second material being different from said first material  an olefin.  
         2 . The communication cable as claimed in claim  1  wherein said first material is a plenum rated insulation material. 
         3 . The communication cable as claimed in claim  2  wherein said second material is a modified non-plenum rated insulation material. 
         4 . The communication cable as claimed in claim  1  wherein said second material is a modified non-plenum rated insulation material. 
         5 . The communication cable as claimed in claim  4  wherein said second material is an olefin. 
     
     
       6. The communication cable as claimed in claim  1  wherein said second material  olefin is a highly brominated and antimony trioxide filled HDPE blended with HDPE. 
     
     
       7. The communication cable as claimed in claim  6  wherein said blend is at a 50/50 ratio. 
     
     
       8. The communication cable as claimed in claim  6  wherein said blend is at a 75/25 ratio. 
     
     
       9. The communication cable as claimed in claim  6   1 wherein said second materialolefin is a hydrated mineral filled polyolefin copolymer HDPE blended with HDPE. 
     
     
       10. The communication cable as claimed in claim  9  wherein said blend is at a 50/50 ratio. 
     
     
       11. The communication cable as claimed in claim  9  wherein said blend is at a 75/25 ratio. 
     
     
       12. The communication cable as claimed in claim  1 , further comprising: 
       a cable jacket, said cable jacket encasing said plurality of twisted pairs and said at least one additional twisted pair.  
     
     
       13. The communication cable as claimed in claim  12  wherein said cable jacket is formed from ethylene-trichlorofluoroethylene. 
     
     
       14. The communication cable as claimed in claim  12  wherein said cable jacket is formed from a polymer alloy. 
     
     
       15. The communication cable as claimed in claim  12  wherein said cable jacket is formed from polyvinylchloride. 
     
     
       16. The communication cable as claimed in claim  1  wherein said plurality of twisted pairs and said at least one additional twisted pair of electrical conductors have different twist lengths. 
     
     
       17. The communication cable as claimed in claim  16  wherein said at least one additional twisted pair has the shortest twist length. 
         18 . The communication cable as claimed in claim  17  wherein said second material includes an olefin base. 
     
     
       19. The communication cable as claimed in claim  18   17 wherein said second materialolefin is a highly brominated and antimony trioxide filled HDPE. 
     
     
       20. The communication cable as claimed in claim  18   17 wherein said second materialolefin is a hydrated mineral filled polyolefin copolymer HDPE. 
     
     
       21. A communication cable for use in a plenum, said communication cable comprising: 
       a first plurality of twisted pairs of electrical conductors having a first  single layer of insulating material about each electrical conductor thereof, said single layer of insulating material about each electrical conductor of said first plurality of twisted pairs being fluoroethylenepropylene ( FEP ); and  
       a second plurality of twisted pairs of electrical conductors having a second  single layer of insulating material about each electrical conductor thereof, said single layer of insulating material about each electrical conductor of said second plurality of twisted pairs including an olefin base and said second plurality of twisted pairs making up no more than half the total number of twisted pairs of electrical conductors.  
         22 . The communication cable as claimed in claim  21  wherein said first material is a plenum rated insulation material. 
         23 . The communication cable as claimed in claim  22  wherein said second material is a modified non-plenum rated insulation material. 
         24 . The communication cable as claimed in claim  21  wherein said second material is a modified non-plenum rated insulation material. 
         25 . The communication cable as claimed in claim  24  wherein said second material includes an olefin base. 
     
     
       26. The communication cable as claimed in claim  21  wherein said second  olefin based insulating material is a highly brominated and antimony trioxide filled HDPE. 
     
     
       27. The communication cable as claimed in claim  21  wherein said second  olefin base insulating material is a hydrated mineral filled polyolefin copolymer HDPE. 
     
     
       28. The communication cable as claimed in claim  21 , further comprising: 
       a cable jacket, said cable jacket encasing said first plurality of twisted pairs and said second plurality of twisted pairs.  
     
     
       29. The communication cable as claimed in claim  28  wherein said cable jacket is formed from ethylene-trichlorofluoroethylene. 
     
     
       30. The communication cable as claimed in claim  28  wherein said cable jacket is formed from a polymer alloy. 
     
     
       31. The communication cable as claimed in claim  28  where said cable jacket is formed from polyvinylchloride. 
     
     
       32. The communication cable as claimed in claim  21  wherein said first plurality of twisted pairs and said second plurality of twisted pairs of electrical conductors have different twist lengths. 
     
     
       33. The communication cable as claimed in claim  32  wherein said second plurality of twisted pairs include the shortest twist lengths. 
     
     
       34. The communication cable as claimed in claim  1  wherein said olefin is a hydrated mineral filled polyolefin in copolymer HDPE. 
     
     
       35. The communication cable as claimed in claim  34  wherein said plurality of twisted pairs and said at least one additional twisted pair of electrical conductors have different twist lengths. 
     
     
       36. A communication cable for use in a plenum, said communication cable comprising: 
       
         a first plurality of twisted pairs of electrical conductors having a single layer of insulating material about each electrical conductor thereof, said single layer of insulating material about each electrical conductor of said first plurality of twisted pairs being formed from a first material; and  
       
       
         a second plurality of twisted pairs of electrical conductors having a single layer of insulating material about each electrical conductor thereof, said single layer of insulating material about each electrical conductor of said second plurality of twisted pairs being formed from a second material including an olefin base, and said second plurality of twisted pairs making up no more than half the total number of twisted pairs of electrical conductors.