FORM2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title of the invention: IMPROVED ARRANGEMENT FOR EARTHING IN ELECTRICAL ENCLOSURES
2. Applicant(s):

(a) NAME : LARSEN & TOUBRO LIMITED
(b) NATIONALITY : An Indian Company
(c) ADDRESS : L & T House, Ballard Estate, Mumbai 400 001,
State of Maharashtra, India
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed:

TECHNICAL FIELD OF THE INVENTION
This invention relates generally to earthing system. More particularly, the present invention relates to an improved arrangement for earthing in electrical enclosures.
BACKGROUND AND THE PRIOR ART
This invention describes the novel arrangement for earthing in distribution boards. The earthing system defines the electrical potential of the conductors relative to the earth conductive surface. The earthing system is usually a direct connection of metal surface of enclosure to earthing wire. It acts as a protection guard in the distribution board by maintaining potential of box to earth potential level and prevents any occurrence of electrocution or damage to human life.
The main objectives of the earthing are to maintain metal enclosure potential to earth potential and thereby provide an alternative low resistance path for the current to flow if any live conductor comes in contact with it. Good earthing system will offer very low resistance to the flow leakage current and hence has to be anti-corrosive in nature. Currently, the earthing arrangement in electrical enclosure is subjected to rust or corrosion. To provide earthing on the painted or coated enclosure, one need to remove painted or coated insulation surface of insulation through scrapper. Action of scrapper, remove the coated surface at intended localized area but it also expose the other surface which is not intended thereby making that unintended surface prone to corrosion. Due to corrosion the conducting path for the leakage current will no more be the least resistive path for the fault current to flow.
This invention rectifies the above problem of rusting by giving a new design of earth scraper which is hexagonal shape and has sharp straight saw shape teeth, which doesn't remove powder coating from the surface but tries to penetrate the coating thereby making a metal to metal contact without exposing surface to corrosion. The present invention finds its application in Distribution Box, Electric Supply Panel, any Equipment with Sheet Metal Body and the like wherever earthing system is used.

OBJECTS OF THE INVENTION
A basic object of the present invention is to overcome the disadvantages/drawbacks of the known
art.
Another object of the present invention is to overcome the problem of rusting in the distribution box near the earth terminal and also to provide better earthing.
Another object of the present invention is to provide an alternative solution to earth scrapper that directly penetrates into the enclosure without removing powder coating.
These and other advantages of the present invention will become readily apparent from the following detailed description read in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
There is provided an earthing arrangement.
According to one embodiment of the present invention, there is provided an improved arrangement for earthing in electrical enclosures comprising atleast one Special Earth washer means (3) having a plurality of teeth ; atleast one washer means (2); atleast one nut means (1); atleast one half nut means (4); atleast one stud means (5); atleast one metal sheet (6); wherein said special earth washer adapted to penetrate said enclosure thereby making a metal to metal contact without removing powder coating from surface of said enclosure without exposing surface from corrosion.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The following drawings are illustrative of particular examples for enabling methods of the present invention, are descriptive of some of the methods, and are not intended to limit the scope

of the invention. The drawings are not to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description.
Fig 1-3 illustrates the special earth washer means (3) cut out from a sheet metal by simple cutting and bending operation.
Fig 4 illustrates the exploded view of earthing arrangement.
Fig 5 illustrates assembly view of the earthing arrangement.
Fig 6 illustrates earthing arrangement of present invention placed on an enclosure.
DETAILED DESCRIPTION OF THE INVENTION
Accordingly in the present invention a better earthing arrangement is provided. By direct penetration of teeth into the coated metal enclosure surface rust or corrosion is avoided. The assembly of this earthing arrangement is discussed below in detail.
Figures 1-3 shows the new design of special earth washer means which is hexagonal in shape thus resists the circumferential motion while tightening the nut. This special earth washer means also has sharp saw-shaped tooth which penetrates through the powder coating thereby making metal to metal contact for proper earthing. This special earth washer is made in sheet metal by simple cutting and bending operation. Size of this special earth washer is decided as per the nut standards as this special earth washer will overlap the specific nut used for fixing earthing stud.
Fig: 4 Shows the exploded view of earthing arrangement in distribution board. The earthing arrangement in distribution board consist of a hex nut and plain stud (An alternative could be a special stud with hex surface at specific location in the middle of it), half thickness hex nut, special earthing washer, plain washer and a standard nut.
Fig: 5&6 shows assembly view of the earthing arrangement.

The Small (or Half)nut with plain Stud or Special Stud having integrated hex nut shape part makes sure that the special washer doesn't move from its place. Therefore, it only pierces the coating on the surface of the body instead of removal of coating or painted surface from unintended area. When we tighten the nut over the plain washer, special earthing washer which is covering Small (or Half) Nut, pierce the coated metal surface of enclosure and makes a metal to metal contact through its sharp straight teeth giving a better earthing thereby not exposing the surface to any corrosion. This arrangement ensures that it remains the least resistive path for conduction in case of any live conductor touch the metal surface of enclosure.
This novel arrangement of earthing system has following components;
1. Nut
2. Plain Washer
3. Special Earthing Washer
4. Small or Half Nut
5. Plain Stud
6. Metal Sheet
ADVANTAGES:
1. Better Earthing with piercing instead of scrapping insulation coating
2. Protection against corrosion of the surface of enclosure
3. Cost effective
4. Assembly friendly.
Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the embodiments herein with modifications. However, all such modifications are deemed to be within the scope of the claims.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the embodiments described herein and all the statements of the scope of the embodiments which as a matter of language might be said to fall there between.

WE CLAIM:
1. An improved arrangement for earthing in electrical enclosures comprising:
atleast one Special Earthing washer means (3) having a plurality of teeth;
atleast one washer means (2);
atleast one nut means (1);
atleast one half nut means (4);
atleast one stud means (5);
atleast one metal sheet (6);
wherein said special earth washer adapted to penetrate said enclosure thereby making a metal to metal contact without removing powder coating from surface of said enclosure without exposing surface from corrosion.
2. Arrangement as claimed in claim 1 wherein said special Earthing washer means having substantially hexagonal shape.
3. Arrangement as claimed in claim 1 and 2 wherein said teeth having substantially sharp straight saw shape preventing removal of said coating.
4. Arrangement as claimed in claim 1 wherein said special earth washer means (3) adapted to resist circumferential motion while tightening said nut means.
5. Arrangement as claimed in claim 1 wherein said Special Earhting washer means (3) cut out from a sheet metal by simple cutting and bending operation.

6. Arrangement as claimed in claim 1 wherein said half nut means having substantially integrated hex nut shape adapted to restrict position of said special earth washer.
7. An improved arrangement for earthing in electrical enclosures as herein described and illustrated with reference to accompanying drawings.