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 MAGNETIC FRAME DESIGN TO
INCREASE BLOW OUT FORCE ON AN ARC
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
The present invention relates generally to a circuit breaker assembly. More particularly the invention relates to an improved magnetic release arrangement for a circuit breaker to provide substantially increased breaking capacity.
BACKGROUND AND THE PRIOR ART
The present invention is related to low voltage circuit breaker. The device is used for protection of electrical lines from consequences of an overload & short circuit current. They have generally thermal release, electromagnetic release & contact arrangement.
A normal circuit breaker forms contact system by a fix contact & moving contact. Contact is opened in arc chamber & arc is guided using arc runner to arc chute (arc splitter). When contact is opened during short circuit, arc is formed. Then this arc is broaden in arc chamber & pulled towards arc chute because of magnetic blowing field. Then it is split in arc chute & extinguished. Greater the speed at which arc moves towards arc chute, less will be the Ft energy passing through breaker, thereby causing less damage which ultimately increase breaking capacity.
US7081596B2 provides an arc-quenching device for circuit breakers having double-break contacts for use in low-voltage distribution systems. Provided around a prechamber is a magnetic shield for the purpose of intensifying the magnetic blowing action on an arc formed between the arc guide rails of the prechamber. In addition, a blowing loop is inserted in the arc-quenching circuit and extends in sections parallel to an arc guide rail. Prechamber insulation having a bulge constricting the arc area likewise serves the purpose of optimizing the arc run.
Limitation with this concept is that the device is suitable only for double break contact system. The magnetic release frame is not used in an optimum manner in order to produce increased blow out force. The novel feature is to use magnetic coil frame in innovative way to increase the blow out force on an arc during its running and splitting phase.

The present invention therefore provides an optimized arrangement of magnetic release frame so as to increase magnetic blowing force. The magnetic frame is placed in an electrical path in such a way that the current direction in the frame helps to increase the magnetic blow out force during short circuit condition. This causes arc to move more rapidly & ultimately increases breaking capacity of circuit breaker.
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 provide an improved magnetic release arrangement for a circuit breaker to provide substantially increased breaking capacity.
Yet another object of the present invention is to provide for faster arc splitting.
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 magnetic release arrangement for a circuit breaker to provide substantially increased breaking capacity.

Other embodiment of the present invention is to provide an improved magnetic release arrangement for a circuit breaker to provide substantially increased breaking capacity, said arrangement comprising a magnetic arc runner connected to a magnetic frame ; a coil means placed in said magnetic frame, upper end of said coil means connected to an upper terminal ; a bypass link connected between said upper terminal and said magnetic frame; a moving core integrated with a bobbin and a fixed core connected and placed in said coil means; a plurality of insulation means provided alongside a plurality of ferromagnetic plates; an arc chute assembly; at least one terminal arc runner; at least one lower terminal; atleast one moving contact; wherein said coil means and said fixed contact defining a first electrical path; wherein said bypass link along with said magnetic frame and magnetic arc runner defining a second electrical path; wherein during short circuit one arc root jumps from said fixed contact to said magnetic arc runner and another arc root jumps from said moving contact to said terminal arc runner and during said arc root jumps an electrical path is established consisting of said second path, said terminal arc runner and said lower terminal); wherein said magnetic frame along with said magnetic arc runner configured to provide a substantially higher flux density thereby providing a substantial magnetic blow out force on an arc to move said arc substantially rapidly during its running and splitting phase.
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 above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:
Fig 1 illustrates the Perspective view of contact system & flux enhancing arrangement
Fig 2 illustrates another perspective view of contact system & flux enhancing arrangement

Fig 3 illustrates Sectional front view of contact & arcing system. Also shows details of arc movement.
Fig 4 illustrates Perspective view of magnetic release with flux enhancer arrangement assembly.
Fig 5 illustrates Perspective view of magnetic release with flux enhancer arrangement assembly.
Fig 6 illustrates Perspective view of magnetic release with flux enhancer arrangement assembly.
Fig 7 illustrates Perspective view of magnetic release with flux enhancer arrangement assembly.
Fig 8 illustrates Exploded view of magnetic flux enhancer arrangement and insulations.
Fig 9 illustrates Sectional front view of magnetic flux enhancer arrangement showing flux distribution.
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. 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.
DETAILED DESCRIPTION OF THE INVENTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be

made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a coil means" includes reference to one or more of such means.
By the term "substantially" it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.
Accordingly in the present invention there is provided an improved magnetic release arrangement for a circuit breaker to provide substantially increased breaking capacity.
DESCRIPTION OF PARTS:
Magnetic Frame (1) Magnetic Arc Runner (2) Terminal Arc Runner (3) Fixed Contact (4) Moving Contact (5) Upper Terminal (6) Lower Terminal (7) Coil means (8)

Arc Chute Plate (9) Bypass Link (10) Ferromagnetic Plates (11) Insulation means part 1 (12) Insulation means part 2 (13) Arc Chute assembly (14) Bobbin (15) Braid (16) Moving Core (17) Fixed Core (18)
Fig. 1 & Fig. 2 show the prospective views of entire current path including contact system & arc running system. The upper terminal is connected to the coil means and bypass /ink. Another end of the coil means is connected to fix contact. In closed position, fix contact is connected to moving contact. Moving contact in turn is connected to lower terminal via braid. The other end of bypass link, which is also connected to upper terminal, is connected to magnetic frame which is in turn connected to magnetic arc runner.
There are two electrical paths that are initiating from upper terminal (6) - first electrical path (Path 1) & second electrical path (Path 2). First electrical path (Path I) consists of Coil means (8) - Fix contact (4). Second electrical path (Path 2) consists of- Bypass link (10) - Magnetic frame (1) - Magnetic arc runner (2). During normal closed condition, electrical path consists of Upper terminal (6) - Path 1 - Moving contact (5) - Braid (16) - Lower terminal (7) (Fig. 2.)
In the event of short circuit, one arc root jumps from fix contact (4) to magnetic arc runner (2) and another arc root jumps from moving contact (5) to terminal arc runner (3). When the arc jumping takes place, new electrical path is established consisting of Path 2 - Arc (Plasma) -Terminal arc runner (3) - Lower terminal (7).
This new electrical path which has been established after arc jumping increases the blow out force on an arc. Further the arc moves over the arc runner and then gets split and extinguished in

arc chute chamber. The assembling step of magnetic release with flux enhancing arrangement is as given below:
Initially Magnetic arc runner is connected to Magnetic frame as shown in Fig. 4. Further Coil-Fix contact sub-assembly is inserted in Magnetic frame sub-assembly from one side such that the upper end of the Coil can be spot welded with Upper terminal on other side. See Fig. 5. The Bypass link is connected between Upper terminal and Magnetic frame by spot welding.
Then the Moving core with Bobbin is inserted from top side in the Coil means along with Fix core being inserted from bottom side having screw type arrangement. Magnetic release assembly achieved along with Side insulations, Side ferromagnetic plates, Arc chute and Terminal arc runner - Lower terminal - Moving contact assembly makes up final assembly as shown in exploded view in Fig. 8.
The condition for better arc jumping from Fix contact to Magnetic arc runner is that the impedance of Path 2 should be less than the impedance of Path 1. After arc jumping from Fix contact to Magnetic arc runner takes place along with arc jumping from Moving contact to Terminal arc runner, the electrical path switches from Path 1 to Path 2. The unique profile of path 2, due to the unique Magnetic frame & Magnetic arc runner arrangement, helps to increase the blow out force on arc during running and splitting phase.
The flux pattern during running & splitting phase of an arc is as shown in Fig. 9. The limbs of Magnetic arc runner & Magnetic frame which are in near proximity boost the flux density on A-side of an arc due to flux vector addition (as shown in Fig. 9.). At the same time, the flux density on B-side of an arc is at minimal due to the vector cancellation of Arc flux and Magnetic arc runner flux. Arc root on Magnetic arc runner (at point X) experience the highest blow out force due to high flux density difference on its either side.
It is required to have high magnetic blowout forces to move arc more rapidly. More the speed of arc less is the erosion of contact. This finally increases breaking capacity & electrical life of

product. Current invention is related to optimum use of Magnetic release frame in order to increase the blow out force on an arc during running and splitting phase.
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 magnetic release arrangement for a circuit breaker to provide substantially increased breaking capacity, said arrangement comprising: a magnetic arc runner (2) connected to a magnetic frame (1);
a coil means (8) placed in said magnetic frame (1), upper end of said coil means (8) connected to an upper terminal (6);
a bypass link (10) connected between said upper terminal (6) and said magnetic frame(l); a moving core (17) integrated with a bobbin (15) and a fixed core (18) connected and placed in said coil means (8);
a plurality of insulation means (12, 13) provided alongside a plurality of ferromagnetic plates (11);
an arc chute assembly (14); at least one terminal arc runner (3); at least one lower terminal (7); atleast one moving contact (5);
wherein said coil means (8) and said fixed contact (4) defining a first electrical path; wherein said bypass link (10) along with said magnetic frame (1) and magnetic arc runner (2) defining a second electrical path;
wherein during short circuit condition one arc root jumps from said fixed contact (4) to said magnetic arc runner (2) and another arc root jumps from said moving contact (5) to said terminal arc runner (3) and during said arc root jumps an electrical path is established consisting of said second path, said terminal arc runner (3) and said lower terminal (7);
wherein said magnetic frame (1) along with said magnetic arc runner (2) configured to provide a substantially higher flux density thereby providing a sufficient magnetic blow out force on an arc to move said arc substantially rapidly during its running and splitting phase.

2. Arrangement as claimed in claim 1 wherein said moving contact (5) connected to said lower terminal (7) through a plurality of braids (16).
3. Arrangement as claimed in claim 1 wherein said first electrical path and said second electrical path is initiating from said upper terminal (6).
4. Arrangement as claimed in claim 1 wherein said moving core (17) connected to said fixed core (18) through a screw arrangement.
5. Arrangement as claimed in claim 1 wherein said second electrical path having substantially lower impedance than said first electrical path.
6. An improved magnetic release arrangement for a circuit breaker to provide substantially increased breaking capacity as herein described and illustrated with reference to accompanying drawings.