FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION A lead termination assembly.
APPLICANT(S)
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR(S)
Panwar Arya and Edison Denny Chelladurai; of Crompton Greaves Limited, Transformer (T3) Division, Plot No. 29, 3I& 32 New Industrial Area No:l, AKVN, Madideep - 462046, Madhya Pradesh, India; both Indian Nationals.
PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

FIELD OF THE INVENTION:
This invention relates to the field of electrical and mechanical engineering and to electro-mechanical assemblies.
Particularly, this invention relates to a lead termination assembly.
BACKGROUND OF THE INVENTION:
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding.
If a load is connected to the secondary, current will flow in the secondary winding, and electrical energy will be transferred from the primary circuit through the transformer to the load. In an ideal transformer, the induced voltage in the secondary winding (Vs) is in proportion to the primary voltage (Vp) and is given by the ratio of the number of turns in the secondary (AQ to the number of turns in the primary (Np) as follows:

In the transformer, there are leads which are come out from windings.
There is a requirement of lead termination assembly, specifically in large rated EHV Power Transformers (Lead Termination of Intermediate voltage winding of

Auto Transformers).
OBJECTS OF THE INVENTION:
An object of the invention is to provide an improved lead termination assembly.
Another object of the invention is to provide a relatively inexpensive lead termination assembly.
Yet another object of the invention is to provide an improved lead termination assembly which required reduced lead time for manufacturing.
Still another object of the invention is to provide an improved lead termination assembly with relatively wider flexibility in terms of physical assembly.
SUMMARY OF THE INVENTION:
According to this invention, there is provided a lead termination assembly comprising a substantially t-shaped tubular assembly further comprising the layers of:
a. innermost layer formed of an elongate metal tube electrode;
b. intermediate layer formed of paper insulation enveloping said elongate metal
tube electrode; and
c. outermost layer formed of pressboard barrier insulation across pre-defined
areas of said metal tube electrode.
Typically, said metal tube is a copper tube.

Preferably, said metal tube is an enameled Copper tube.
Typically, said metal tube comprises a lower bent portion such that it bends orthogonally towards an operative first direction.
Typically, said metal tube comprises an upper slightly bent portion such that it deviates from the generally operatively vertical elongate body towards an operative second direction.
Typically, said metal tube comprises a second tube component fused orthogonally towards an operative first direction, at a portion where an upper bend starts.
Typically, said paper insulation winding which forms the intermediate layer is tapered at the edges of joints of said assembly, in a pre-defined fashion.
Typically, said paper insulation winding comprises paper insulation winding of varying parameters at pre-defined locations of said assembly, said parameters being selected from a group of parameters consisting of amount of overlap of paper insulation, portions of overlap, moisture content, thickness, and the like parameters in order to achieve smoother flux lines or equi-potential flux lines.
Typically, said pressboard barrier insulation is located at zones / areas of said assembly where it is required to control electrostatic stress.
Typically, said assembly comprises a first winding end section at the end of a lower bent portion.

Typically, said assembly comprises a second winding end section at the end of a second tube component.
Typically, said assembly comprises an end bushing shield at the operative upper end of an upper slightly bent portion of a metal tube of said assembly.
Typically, said assembly comprises an end bushing shield at the operative upper end of an upper slightly bent portion of a metal tube of said assembly, said bushing shield being co-axially mounted with said upper slightly bent portion, and hence being deviated / angled with respect to a general axis of said elongate tube.
Typically, said assembly comprises a metallic shielding at pre-defined points of said metal tube.
Typically, said assembly comprises a metallic shielding at pre-defined points of said metal tube, said metal shielding being provisioned by Aluminum or Copper foils such that it touches the Copper tube at said pre-defined points, especially at the joints.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a lead termination assembly of the prior art.
The invention will now be described in relation to the accompanying drawings, in
which:
Figure 2 illustrates a lead termination assembly;

Figure 3a illustrates an exploded schematic configuration of the lead termination assembly; and
Figure 3b illustrates an assembled schematic configuration of the lead termination assembly.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 illustrates a lead termination assembly of the prior art.
It is a tube (102) with an angled bushing shield (104). The entire component is a molded component which increases its cost. Also, it includes a duct.
According to this invention, there is provided a lead termination assembly.
Figure 2 illustrates a lead termination assembly.
In accordance with an embodiment of this invention, there is provided an elongate metal tube (10) electrode. This forms the innermost layer. Typically, this is a t-shaped tube. The metal tube is a copper tube to carry current carrying conductors. Preferably, the metal tube is an enameled Copper tubular electrode. The elongate metal tube comprises a lower bent portion (12) such that it bends orthogonally towards an operative first direction. The elongate metal tube comprises an upper slightly bent portion (14) such that it deviates from the generally operatively vertical elongate body towards an operative second direction. At the portion, the upper bend starts, the tube includes a second tube component (16) fused orthogonally towards the operative first direction. This forms the substantially t-shaped tube.

Figure 3 a illustrates an exploded schematic configuration of the lead termination assembly. Figure 3b illustrates an assembled schematic configuration of the lead termination assembly. The parts (1, 2, 3, and 4) which form the lead termination assembly are disclosed in the drawings.
In accordance with another embodiment of this invention, there is provided a paper insulation (20) enveloping the elongate t-shaped metal tube. This paper insulation forms the intermediate layer. The paper insulation eliminated the need for having molded components, thereby reducing cost. The incorporation of insulation paper provides greater flexibility in terms of physical assembly of the lead wire assembly. At each of the joints of the lead termination assembly, there is no proper termination as there are sharp edges. Joints tend to be stressful. Hence, the paper insulation winding which forms the intermediate layer is tapered at the edges of the joints. This taper is depicted by reference numeral 30 at each of the portions of the lead termination assembly where taper is required. Typically, the paper insulation parameters are controlled throughout the lead termination assembly during its designing phase. There are pre-determined parameters as to how much overlap of paper insulation at what portion is to be achieved. There are pre-determined parameters as to how much moisture content, thickness, and the like parameters in the paper insulation are to be achieved. The induction of tapers provides smoother flux lines or equi-potential flux lines at the joints and end portions.
In accordance with yet another embodiment of this invention, there is provided a pressboard barrier insulation across pre-defined areas of the assembly. This is the outermost layer. This layer is used only where it is required to control the electrostatic stress in that area.

In accordance with still another embodiment of this invention, there is provided a first winding end section (25) at the end of the lower bent portion (12).
In accordance with an additional embodiment of this invention, there is provided a second winding end section (35) at the end of the second tube component (16).
In accordance with yet an additional embodiment of this invention, there is provided an end bushing shield (45) at the operative upper end of the upper slightly bent portion (14) of the metal tube. This bushing shield is co-axially mounted with the upper slightly bent portion (14), and hence is deviated / angled with respect to the general axis of the elongate tube. This eliminates the need to specially angle the bushing which was prevalent in the prior art, and required additional costs.
In accordance with still an additional embodiment of this invention, there is provided a metallic shielding at pre-defmed points of the metal tube. The metal shielding is provisioned by Aluminum or Copper foils such that it touches the Copper tube, especially at the joints. Therefore, a generally smooth profile is obtained with smoother flux lines.
According to a non-limiting exemplary embodiment, the cost of a prior art lead termination assembly which cost Rs. 15-20 lakhs was reduced to Rs. 1.5-2 lakhs due to removal of molded component assembly. Also, time of manufacturing is very less as compared to the assembly of the prior art.
The technical advancement of this invention lies in elimination of molded components and in incorporating paper insulation based components in the defined shape and configuration such that the end bushing can be easily fitted without

change in design or molding. Also, stress free-joints and winding ends are introduced which result in smoother flux lines and equi-potential flux lines. Further, the removal of oil duct and the usage of three layers for lead termination to reduce the cost of manufacturing contribute to inventive step.
While this detailed description has disclosed certain specific embodiments of the present invention for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We claim,
1. A lead termination assembly comprising a substantially t-shaped tubular
assembly further comprising the layers of:
a. innermost layer formed of an elongate metal tube electrode;
b. intermediate layer formed of paper insulation enveloping said elongate
metal tube electrode; and
c. outermost layer formed of pressboard barrier insulation across pre
defined areas of said metal tube electrode.
2. A lead termination assembly as claimed in claim 1, wherein said metal tube is a copper tube,
3. A lead termination assembly as claimed in claim 1, wherein said metal tube is an enameled Copper tube.
4. A lead termination assembly as claimed in claim 1, wherein said metal tube comprising a lower bent portion such that it bends orthogonally towards an operative first direction.
5. A lead termination assembly as claimed in claim 1, wherein said metal tube comprising an upper slightly bent portion such that it deviates from the generally operatively vertical elongate body towards an operative second direction.
6. A lead termination assembly as claimed in claim 1, wherein said metal tube comprising a second tube component fused orthogonally towards an operative first direction, at a portion where an upper bend starts.

7. A lead termination assembly as claimed in claim 1, wherein said paper insulation winding which forms the intermediate layer is tapered at the edges of joints of said assembly, in a pre-defined fashion.
8. A lead termination assembly as claimed in claim 1, wherein said paper insulation winding comprising paper insulation winding of varying parameters at pre-defined locations of said assembly, said parameters being selected from a group of parameters consisting of amount of overlap of paper insulation, portions of overlap, moisture content, thickness, and the like parameters in order to achieve smoother flux lines or equi-potential flux lines.
9. A lead termination assembly as claimed in claim 1, wherein said pressboard barrier insulation being located at zones / areas of said assembly where it is required to control electrostatic stress.
10. A lead termination assembly as claimed in claim 1, wherein said assembly comprising a first winding end section at the end of a lower bent portion.
11. A lead termination assembly as claimed in claim 1, wherein said assembly comprising a second winding end section at the end of a second tube component.
12. A lead termination assembly as claimed in claim 1, wherein said assembly comprising an end bushing shield at the operative upper end of an upper slightly bent portion of a metal tube of said assembly.

13. A lead termination assembly as claimed in claim 1, wherein said assembly comprising an end bushing shield at the operative upper end of an upper slightly bent portion of a metal tube of said assembly, said bushing shield being co-axially mounted with said upper slightly bent portion, and hence being deviated / angled with respect to a general axis of said elongate tube.
14. A lead termination assembly as claimed in claim 1, wherein said assembly comprising a metallic shielding at pre-defined points of said metal tube.
15. A lead termination assembly as claimed in claim 1, wherein said assembly comprising a metallic shielding at pre-defined points of said metal tube, said metal shielding being provisioned by Aluminum or Copper foils such that it touches the Copper tube at said pre-defined points, especially at the joints.