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 COVER ASSEMBLY FOR
INTERNAL ACCESSORIES OF CIRCUIT BREAKERS
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 switchgear applications. More particularly the present invention relates to an improved cover assembly for internal accessories like under voltage release; shunt release etc. of circuit breakers. The invention finds its application under voltage and shunt release where wire termination and finger protection is required.
BACKGROUND AND THE PRIOR ART
An under-voltage (UV) release is used in circuit breaker to offer protection against under voltage or zero voltage condition. Under voltage release trips the circuit breaker mechanism when the voltage across the terminals of the release falls below a predetermined value; hence it goes along with the circuit breaker module as internal accessories. Shunt release is used for electrical tripping of the circuit breaker by a control supply voltage, mainly for remote tripping. Both UV and shunt release uses electromagnetic coil and amplification mechanism to provide the trip signal.
In order to protect the electromagnetic coil from external damage and also to protect the amplification mechanism from external interference an outer cover is required. Also a proper termination of coil terminal wire is required to prevent damage due to pulling of wire externally. In view of the available products and their drawbacks the present inventors after doing an extensive research and experimentations have found that there remains space for developments of new and improved terminal cover assembly for internal accessories.
The present invention therefore provides an improved arrangement wherein wire from coil is terminated properly in terminal cover and covers the under voltage or shunt release externally. This invention is generally used for switchgear applications and more particularly for a moulded case circuit breaker & circuit breakers where internal accessories like UV & shunt release are used. This application is more relevant to under voltage and shunt release where wire termination and finger protection is required.

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 protect the electromagnetic coil from external damage and also to protect the amplification mechanism from external interference.
Another object of the present invention is to provide means for a proper termination of coil terminal wire to prevent damage due to pulling of wire externally.
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
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.
There is provided an improved terminals cover for UV and shunt release.
According to one aspect of the present invention, there is provided an improved cover assembly for internal accessories like under voltage release, shunt release etc. of circuit breakers, said assembly comprising at least one terminal holder; at least one terminal cover; at least one screw cover assembled at the bottom of said terminal holder; at least a pair of box clamp arrangement positioned substantially along one side whereby a plurality of coil terminal wires are soldered for facilitating termination; wherein said box clamp held by said terminal cover configured to

withstand screw tightening load thereby protecting screw tightening load from transferring to coil.
Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
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. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
Reference is first invited to Fig 1 where the under voltage / shunt release 2 with terminal cover assembly 1 is illustrated.
Fig 2 illustrates terminal cover assembly 1.
Fig 3 illustrates terminal cover assembly 1 in exploded view, which consist of terminal holder 3, box clamp assembly 4, and bottom cover 5. Also it shows profiles in terminal holder 3, snap fit 3a, Customer wire routing 3b and slot for screw access 3c. 5a is slot for coil terminal wire entering box clamp.
Fig 4 illustrates box clamp assembly with screw 6, washer 7 and box clamp 8.

Fig 5 illustrates Terminal cover assembly 1; Electromagnetic coil 11; Protecting surface of terminal cover 12.
DETAILED DESCRIPTION OF THE INVENTION
Accordingly in the present invention, there is provided an outer cover to protect the electromagnetic coil from external damage and also to protect the amplification mechanism from external interference. Also a proper termination of coil terminal wire is required to prevent damage due to pulling of wire externally. Hence in this invention wire from coil is terminated properly in cover assembly and covers the under voltage or shunt release externally as shown in the fig 1.
Cover assembly consists of a terminal holder which carries two box clamp assembly. Box clamp assembly consists of box clamp, washer and screw as shown in fig 4. The terminal wires from coil need to be soldered with the box clamp. The external wires from the customer end will be connected to the coil through box clamp.
The box clamp arrangements are positioned in such a way that space inside the breaker is better utilized i.e. considering the space constrains. In earlier design the box clamp arrangements are mounted on the either sides of the coil such that the symmetry is achieved but the draw back in that system is the required travel for screw tightening is achieved by compromising the plastic strength below the box clamp area. This has risk of terminal cover breakage due to the load application while screw tightening leading to damaging of the coil inside the cover. The cover cannot be taken up due to the space constraints in the upward direction in one side of the release.
Hence to address this issue in this invention the box clamps has been positioned along one side of the under voltage or shunt release. Since there was space constrain only on one side of the release the box clamps have been shifted to the other side. Because of this the space on the other side of the breaker has been better utilized, the plastic portions are strengthened also the travel required for tightening wires is achieved without compromising the functional requirement.

The terminal holder is designed in such a way the screws will not be missed during installation or working. For accessing the screws holes are provided on the terminal cover, the holes for screw access are designed so as it will not allow finger to touch any live part. The cover is designed for Ingress protection against finger entering.
An additional cover has been provided from the bottom of the terminal block as shown in the exploded view in fig 3, covering the box clamp assembly so as to protect the coil from damage due to tightening load. Slots are provided on the bottom cover for the wire entering from coil to reach the box clamp so as it will be soldered with the box clamp. The wire from the coil is directly solder to the box clamp hence additional component has been avoided which saves space and cost. Since the wire has to be soldered to the box clamp it needs to be a conducting material.
The terminal holder is fixed in the side plates of the under voltage or shunt release. Terminal holder is initially mounted on the slot in the top of the side plate, then rotated and pressed towards the side plates; the snap fit in the terminal holder deflects and holds the terminal cover assembly in position. Thus terminal cover is held rigid in the side plate.
An under voltage and shunt release are internal accessories, which are assembled at the customer end. Hence this invention gives a terminal cover which covers and protects functional parts and also offers protection for the customer from reaching the live parts. Terminal block has high strength which will withstand the external load.
Terminal block described in this invention allows the customer end interface suitable for various cable size requirements. Release itself consists of terminal block which eliminates the external terminal block requirement at customer end. Release with prewired (without terminal block) will have wire of only specific length, in the application where the wire length need to be long for connection will require an additional wire to be connected externally. In this invention this need has been addressed which allows the customer interface to connect wire of any length. Termination with one side alignment makes the release compact with in the given space considering the creep-age and clearance requirements pertaining to standards.

Terminal block consist of bottom cover which protects the screw tightening load from transferring to coil. Box clamp assembly consists of washer which moves along with screw, which protects the external in coming wire strands from damage caused by screw tightening action. Same terminal cover used to protect the electromagnetic coil, providing termination is extended to protect the mechanism components like spring which can be misaligned due to external handling as in existing design where spring is exposed and latch which is a functional component.
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 cover assembly for internal accessories like under voltage release, shunt
release etc. of circuit breakers, said assembly comprising:
at least one terminal holder;
at least one terminal block having a bottom cover;
at least one screw cover assembled at the bottom of said terminal holder;
at least a pair of box clamp arrangement positioned substantially along one side whereby a plurality of coil terminal wires are soldered for facilitating termination;
wherein said box clamp held by said terminal block configured to withstand screw tightening load thereby protecting screw tightening load from transferring to coil.
2. Assembly as claimed in claim 1 wherein said terminal block configured to protect an amplification mechanism from external interference.
3. Assembly as claimed in claim 1 wherein said terminal holder having a snap fit profile adapted to deflect and hold said terminal block assembly in position.
4. Assembly as claimed in claim 1 wherein said terminal block having a wire routing means and a pair of slots for screw access.
5. Assembly as claimed in claim 1 wherein said box clamp fitted with at least one screw and washer adapted to prevent external wires from damage.

6. Assembly as claimed in claim 1 wherein said box clamp is made substantially of an electrically conducting material.
7. An improved terminal cover assembly for internal accessories like under voltage release, shunt release etc. of circuit breakers as herein described and illustrated with reference to accompanying drawings.