FORM -2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL
Specification
(Sec Section 10 and rule 13)
COMMUNICATION CABLES

FINOLEX CABLES LIMTIED
an Indian Company of 26-27, Mumbia-Pune Road. Pimpri Pune 411 018, Maharashtra, India
THE FOLLOWING SPECIFICATION DESCRIBES THE INVENTION

Field of Invention:
This invention relates to the field of communication cables.
Background of the Invention:
Presently, solid copper conductor is used to manufacture LAN (Local Area Network) cable for high speed connectivity and bandwidth requirements of computer / internet cabling. The LAN CAT cables arc generally made of solid copper with 0.5mm nominal conductor diameter. These cables are insulated with polyethylene, colour coded and twisted to form pairs laid up to form core. The colour coded pairs of cables are further jacketed with a PVC compound.
Thus there is a need for lighter and cheaper cables without compromising their performance.
Objects of the Invention:
It is an object of the invention to provide a light weight cable for communication purposes.
Another object of this invention is to provide a cable which is economical.
Yet another object of this invention is to provide a cable with improved performance characteristics.
Brief Description of the Drawings:
Fig 1 of accompanying drawings illustrates the cross section of a copper clad aluminum conductor in accordance with this invention; and


Figure 2 of the accompanying drawings illustrates the LAN CAT cable with four pairs of twisted Copper clad aluminum cables, in accordance with this invention.
Detailed Description of the Invention:
In accordance with this invention, the conductor is made from copper clad aluminum material. The copper clad aluminum wire is a bimetallic wire with cladding of copper concentrically covering inside it an aluminum core. The copper tape is wrapped around on solid aluminum wire and seam welded followed by compression through various dies to bond mctallurgically at the interface through an essentially cold solid process which helps optimizing properties of both aluminum and copper. The use of this type of conductor is developed for high frequency communication application wherein the outer copper surface is used for high frequency signals to travel with a principle of "skin effect" such that only the outer conductor needs to be of copper and the inner material is of aluminum to make the product light in weight and cheaper. By use of copper on the surface of the conductor, it offers minimum resistance. The copper cladding thickness surrounding the aluminum core measures nominally 4% of the overall wire diameter which corresponds to maximum 15% of copper on outer layer and balance is aluminum core at the centre. The maximum resistivity at 20°C is 0.026 Ohms mm" per meter. The maximum density at 20°C is 3.63gms /cm3.
The pure copper has resistivity of 0.17ohms/ mm per meter (100% IACS -International Annealed Copper Standard) which corresponds to density of 8.89gms/ cm .
The final CCA wire of nominal diameter 0.5mm is cold drawn by using the thicker wire of CCA with the same copper percent, which typically is nominal 4% on wire

drawing machine. The drawn final wire of 0.5mm has same uniform copper content as that of the feed wire. The wire is annealed before use for the higher flexibility during the handling.
The CCA conductor after drawing and annealing with required size, is coated with insulation with polyethylene with different colours.
The four pairs are formed with close different lays for each pair and are laid up to form the core. The laid up cable is jacketed with fire retardant type of PVC as a protecting layer.
The design of LAN cables using copper clad aluminum conductor instead of solid copper conductor in accordance with this invention has the following advantages:
1. Copper clad aluminum conductor is lighter than solid copper reducing the overall weight of the cable.
2. High frequency signals are needed for transmission of data / video signals using LAN cables and such frequencies travel only on the surface of the conductor. Hence combining the bimetallic properties of providing copper on the surface to maintain the same signal quality (like solid copper) the new cable design offer lower price due to savings in using aluminum ( a cheaper conductor) in the inner core of the conductor.
During the use, the galvanic corrosion on CCA conductor can occur due to presence of moisture at the point of termination and due to exposure to the atmosphere. This can lead to degradation in the performance if no proper care is taken. This can be avoided by using the sealed connectors and / or using heat

shrinkable tubings to cover the exposed portion. This procedure ensures longer and trouble free life in network operation.
While considerable emphasis has been placed herein on me components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the invention These and other changes in the preferred embodiment as well as other embodiments of the invention will be apparent to those skilled in the art from the disclosure herein whereby it is to be distinctly understood that the foregoinh descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation
Dated this 24th day of October, 2008.
Mohan Dewan Of.R. K.Dewan & Co. Applicants' Patent Attorney