FORM 2
The Patents Act 1970
(39 of 1970)
&
The Patent Rules 2003
COMPLETE SPECIFICATION
(See Section 10 and rule 13)
TITLE OF THE INVENTION:
TERMINATION LINK ASSEMBLY FOR CIRCUIT
BREAKERS
APPLICANT:
LARSEN & TOUBRO LIMITED
L&T House, Ballard Estate, P.O. Box No. 278,
Mumbai, 400 001, Maharashtra,
INDIA.
PREAMBLE OF THE DESCRIPTION:
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICHIT JS TO BE PERFORMED

A) TECHNICAL FIELD
[0001] The present invention generally relates to electrical switching apparatus and particularly to moulded case cir cuit breakers. The present invention more particularly relates to a termination link assembly for a moulded case circuit breaker.
B) BACKGROUND OF THE INVENTION
[0002] Electrical switching apparatus, such as circuit breakers, are employed in diverse capacities in power distribution systems to provide protection for electrical equipment during electrical fault conditions, such as current overloads, short circuits, abnormal level voltage conditions or the like.
[0003] During the installation of a circuit breaker, the terminal links
extending from either line side or load side of a circuit breaker must be connected to its source or load such as bus line or cable lines. The connection may be accomplished by inserting a screw or other rod shaped connector through a hole in the terminal link and through an opening in a connector for source or load. A nut or equivalent receiving or tightening device may then be attached to the screw for securing the connection between the terminal link and the source or load.
[0004] When a screw is used to make the above described connection,
holding a nut for assembly of load/ source connector to the terminal link is clumsy and labor intensive. In some instances, holding the nut by hand is practically impossible and an alternative fastening method may be required.

Furthermore the threaded terminal links use threaded holes which do not allow for any misalignment of parts.
[0005] Presently nut plates are used for termination of most of the
circuit breakers. Nut plates are custom made for each frame and once the threading is damaged, it is difficult to find a replacement as the spare nut plates are not supplied. The nut plates in turn have to be fastened to the housing of the circuit breaker with two screws. For replacing the nut plate, the entire circuit breaker mounting and connections have to be removed and then the nut plate can be accessed. The screw is not insulated from bottom. The terminals are not accessible from bottom for rear connection.
[0006] Hence there is a need to provide an improved terminal link for
circuit breakers which provides accurate fit of the nut in the insulation housing and also to provide for easy assembly and disassembly without the requirement of any additional tools.
[0007] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
C) OBJECT OF THE INVENTION
[0008] The primary object of the present invention is to develop an improved terminal link assembly for circuit breakers.

[0009] Another object of the present invention is to develop an
improved method for the termination of links with circuit breaker using a hex nut.
[0010] Yet another object of the present invention is to develop an
improved terminal link assembly for circuit breakers which enables easy replacement of the nut in case of damages, with the circuit breaker in mounted condition.
[0011] Yet another object of the present invention is to develop an
improved terminal link assembly for circuit breakers which reduces the requirement of tools for fixing the nut plate.
[0012] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
D) SUMMARY OF THE INVENTION
[0013] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
[0014] The various embodiments of the present invention provide a terminal link assembly for circuit breakers. The terminal link assembly comprising a casing and a hex nut press fitted in the casing. The casing is provided with a profile such that there is no dislocation of the hex nut during circuit breaker operation.

[0015] The present invention primarily consists of two parts, a hex nut and the nut housing. The nut can be tightly fit or loosely fit in the insulation housing. This assembly is press fit with the housing of the circuit breaker.
[0016] The nut plate assembly is guided to the circuit breaker housing
such that the application of the tightening torque makes the assembly stable. The nut plate assembly is closely fitted with the circuit breaker housing and is covered from the top by the terminals of the circuit breaker. This prevents the easy release of the nut from the nut plate assembly. The nut plate assembly is slidably moved into the circuit breaker housing until the nut plate assembly comes in contact with the terminal. Further the external conductor is placed over the terminal. The nut plate assembly, the terminal and the external conductor are fastened with a suitable fastening means such as a bolt.
[0017] On removal of the nut plate, the rear of the terminal is
accessible which makes it convenient for the nut plate assembly to be removed from the rear side. In case of any damages, the nut can be replaced with the MCCB in mounted condition. The snap fit is accessible from the front. This can be discomfited with the help of a screw driver or any suitable tool and the nut plate can be slide down and then moved in a horizontal direction to detach from the circuit breaker.
E) BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:

[0019] FIG.l illustrates a nut plate assembly according to one embodiment of the present invention.
[0020] FIG. 2 illustrates the exploded view of the nut plate assembly in the MCCB according to one embodiment of the present invention.
[0021] FIG. 3 illustrates the cross sectional view of the nut plate assembly in an assembled condition according to one embodiment of the present invention.
[0022] FIG. 4 illustrates the top cross sectional view of the nut plate assembly assembled to the circuit breaker according to one embodiment of the present invention.
[0023] FIG. 5 illustrates the top view of the entire circuit breaker assembly according to one embodiment of the present invention.
[0024] FIG. 6 illustrates the cross sectional view of the assembly of termination of links for molded case circuit breaker according to one embodiment of the present invention.
[0025] Although specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.

F) DETAILED DESCRIPTION OF THE INVENTION
[0026] In the following detailed description, a reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.
[0027] The various embodiments of the present invention provide an improved method of termination of terminal links for circuit breakers.
[0028] FIG.l illustrates a nut plate assembly 1 according to one
embodiment of the present invention. The embodiment disclosed herein consists of a hex nut 11 and a nut housing. The hex nut 11 is press fit/ tight fit with the insulating nut plate/casing 12. FIG. la illustrates the exploded view of the nut plate assembly illustrating the hex nut 11 and the nut plate 12. FIG. lb illustrates the top view of the nut plate assembly 1 in an assembled condition with the circuit breaker according to one embodiment of the present invention.
[0029] FIG. 2 illustrates the exploded view of the circuit breaker
assembly according to one embodiment of the present invention. The hex shaped groove 13 is provided in the nut plate/casing 12 and hex nut 11 is inserted into the groove 13 provided. Then the nut plate assembly 1 is inserted into the housing 15 of the circuit breaker. The nut plate assembly 1

slides until it comes in contact with the terminal 14 of the MCCB. The circuit breaker cover 16 is then placed over the breaker housing 15.
[0030] FIG. 3 illustrates the cross sectional view of the nut plate assembly assembled to the circuit breaker according to one embodiment of the present invention. Al and A3 are the axes of the hex nut 11 and the terminal 14 as shown in the FIG. 3. The terminal 14 is fastened on to the hex nut 11 directly. The hex nut 11 is inserted into the hex shaped grove provided in the nut plate/casing 12 as shown in FIG. 1 and FIG. 2. This prevents the movement of the hex nut from its position.
[0031 ] FIG. 4 illustrates the top cross sectional view of the circuit breaker assembly with the nut plate assembly according to one embodiment of the present invention. The guide in the housing 17 is provided for the insulated nut plate 12. The guide 17 in the housing provides a fixed location for the nut casing 12 in the housing 15. As shown in FIG. 4, the nut plate assembly 1 is made to slide into the circuit breaker housing 15 until it touches the terminal 14. A1 and A3 are the axes of the hex nut 11 and the terminal 14 as shown in the FIG. 3. On the inner surface of the breaker housing 15 wall, a snap fit arrangement is provided for inserting and fitting the nut plate assembly 1. The nut plate assembly I is slidably moved first from the bottom in a horizontal direction with respect to the axis of the terminal. Then nut plate assembly 1 is slidably moved from the bottom till the snap fit click is heard. This ensures the nut plate assembly 1 is tightly fit with the breaker housing 15.
[0032] FIG. 5 illustrates the top view of the circuit breaker assembly according to one embodiment of the present invention. As shown in FIG. 5, the entire breaker assembly is performed by a series of steps. In the first step, the nut plate assembly 1 is slidably moved into the circuit breaker housing 15 from the top. Secondly, the nut plate assembly I is slidably moved into

the circuit breaker housing 15 until the nut plate assembly comes in contact with the terminal 14. Further, an external conductor 18 is placed on the terminal 14. The nut plate assembly 1, the terminal 14 and the external conductor 18 are then fastened together with suitabJe fastening means like a bolt 19 (FIG. 6).
[0033] FIG. 6 illustrates the cross sectional view of the assembly of termination of links for circuit breaker according to one embodiment of the present invention. The nut plate assembly 1 is slidably moved into the circuit breaker housing 15 from the top until it touches the terminal 14. Then the external conductor 18 is placed on the terminal 14. The nut plate assembly 1, the terminal 14 and the external conductor 18 are then fastened together with suitable a suitable fastening means for example, a bolt 19 as shown in FIG. 6.
G) ADVANTAGES OF THE INVENTION
[0034] The embodiments of the disclosed invention provide a two part
assembly which makes it easy to assemble and disassemble the nut plate assembly from the circuit breaker. Also, the replacement of the nut can be made with breaker in mounted condition.
[0035] The embodiment uses a standard hex nut for termination of
links, which in turn reduces the cost. The nut is fully covered/ insulated by an insulating housing which prevents the damage of the nuts. The terminal is easily accessible for rear connection by removing the nut plate. Further, no additional tools are required fixing the nut plate to the circuit breaker. Also, it enables direct contact of termination links to breaker terminals.

[0036] Although the invention is described with various specific
embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.
[0037] It is also to be understood that the following claims are
intended to cover all of the generic and specific features of the present invention described herein and all the statements of the scope of the invention which as a matter of language might be said to fall there between.

CLAIMS
What is claimed is:
1) A terminal link assembly for circuit breakers, the assembly comprising:
a casing;
A hex nut press fitted in the casing;
Wherein the casing is provided with a profile such that there is no dislocation of
the hex nut during circuit breaker operation.
2) The terminal link assembly for circuit breakers according to claim 1, wherein the profile of the casing includes a geometry compatible with a geometry of the hex .nut.
3) The terminal link assembly for circuit breakers according to claim 1, wherein the casing in an insulation casing.
4) The terminal link assembly for circuit breakers according to claim 2, wherein the hex nut is arranged such that the hex nut is completely enclosed by the insulation casing.
5) The terminal link assembly for circuit breakers according to claim 1, wherein the assembly is slidably moved into the breaker housing until the casing comes in contact with a terminal of the circuit breaker.
6) The terminal link assembly for circuit breakers according to claim 1, wherein the assembly is guided in the circuit breaker housing such that the application of the tightening torque makes the assembly stable.
7) The terminal link assembly for circuit breakers according to claim 1, wherein the casing is snap fit with an inner wall of the circuit breaker housing.

8) The terminal link assembly according for circuit breakers to claim 1, wherein the nut is covereing from the top by the terminals of the circuit breaker such that the nut does not get detached from the casing.
9) The terminal link assembly for circuit breakers according to claim 4, wherein further comprising a conductor placed over the terminal.
10) The terminal link assembly for circuit breakers according to claim 1,
further comprising a fastening means to interconnect the casing, the terminal and
the external conductor.
11) The terminal link assembly for circuit breakers according to claim 10,
wherein the fastening means is a bolt.