FIELD OF INVENTION
This invention is directed to an arc chute assembly for improved arc quenching in electric switching device. The switching device includes air circuit breaker which can also be called low voltage circuit breaker.
BACKGROUND/PRIOR ART
The arc chute plays a major role in proper arc quenching in a low voltage circuit breakers. The arc chute consists of stack of deion plates made up of magnetic material to attract, split-up 85 cool the arcs. The stack of deion plates is trapped in between two plates known as lining made up of electrically insulating material. The function of deion plates is to split the arc in a plurality of arcs of approximately equal length which results in higher arc voltage and distinctly greater dielectric strength after current zero.
Now reference may be made to the following patents:-
US Patent No. 7,705,263 relates to an. arc chute assembly which comprises a housing having a lateral axis and • a quenching portion disposed within the housing. The quenching portion comprises at least two deion plates being spaced along the lateral axis of the housing and each having a cut portion.The cut portions are staggered along the lateral axis with respect to one another and are configured to mitigate an arc. The arc chute assembly may comprise a housing, deion plates, an insulating member, a filter and stability member. Furthermore, the deion plates may be composed of ferromagnetic material such as steel alloys.

In the above, effectiveness of quenching is comparatively less.
Publication No. US2014151340 (Al) is directed to an arc chute arrangement for arc quenching in electrical switching devices comprising a plurality of deion plates, wherein each of said deion plates further comprises a pair of plates, electrically connected to each other, having an ablative, material sandwiched there between;a lining means for holding said deion plates. Said deion plates having a chamfered profile at one corner to minimize the possibility cf flash-over arc restrike and to generate high magnetic field that drive the arc inside arc chute and said chamfered profile arranged alternatively. The deion plate consists of stack assembly of ablative material sandwiched in between two metal plates made up of ferromagnetic material. The ablative material generates gasses exactly near the arc roots resulting in rapid buildup of dielectric strength of arcing region and faster cooling of arc.
Indian Publication No. 2939/MUM/2009relates to an improved arc chute assembly having an ablative gassing material. In this arc cooling is enhanced by the use of a gassing material within an arc chute assembly having a support structure for the stack of arc plates also known as de-ion plates.
The above are quite expensive and involve complex design.
Publication No. US3641294 (A) discloses arc chute for electric circuit breakers. It includes a stack or plurality of spaced-apart plates, preferably made of magnetizable material, which are disposed between a pair of arc runners.After the arc has moved through the stack, flashover or reignition of the arc across the top of the stack is likely to occur. All plates in stack are of the same configuration and size and may be assumed to be made of magnetizable material such as copper-plated steel.

Indian Publication No. 202/MUM/2010 relates to an arc chute assembly having de-ion plates comprising different material coatings with different functions so as to facilitate reduction in the arcing time thereby resulting in fast quenching of the arc by means of enhancing cathode root formation aiding in faster travel of the arc into the arc chutes. It is used for different material coatings selected from group of materials like silver, iron, zinc, copper, tungsten, nickel, osmium and the like.
Indian Publication No. 330/MUM/2012 relates to arc chute assembly for circuit breakers. The metal plate used can be of ferromagnetic material or any other refractory materials for arc movement. The metal plate is coated with nickel, zinc or copper for improved arc movement.
Here coating of material is carried out on ferromagnetic plate to strengthen the plate withstanding capacity against the arc quenching.
Indian Publication No. 572/MUM/2011 relates to an arc chute assembly for the electrical switching devices. The metal plates can also be coated with conducting material like copper, nickel etc. to enable faster movement of arc. The arc plate may comprise at least one metal plate having low electron affinity, such as rear earth materials.
Earth material is not easily available and quite expensive.
US 2337949 relates to the combintion in a circuit breaker of a pair of contacts at least one of which is movable to close and open an electric circuit between said contacts.Arc chute members on opposite sides of the path of movement of

said movable contact are made of a material which is electrically Insulating to cause an arc between said contacts to pass between said members andmagnetic to provide an increased magnetic field thereby accelerating the movement of the arc between said members.There is provision of a pluralityof sheets of magnetic mtaerial adjacent to the edges of said chute members toward which the arc moves extending transversely with respect to the arc.
It is having more weight due to more number of magnetic plates, which adds to cost.
According to another existing .technology, plate of high permeable material with maximum thickness of 0.65 mm is employed, which is quite expensive requiring more quenching time.
In order to reduce the quenching time, the contact fingers in the switching device is provided more in number (6-8) adding to cost,which makes it further expensive.
in view of the above, there is a requirement to develop an arc chute assembly for improved arc quenching in electric switching device, wherein the arc chute assembly constitutes an optimized design to achieve improved performance with cost effectiveness.

OBJECTS OF THE INVENTION
An object of this invention is to propose an arc chute assembly for improved arc quenching in electric switching device which overcomes disadvantages associated with the prior art.
Another objective of the present invention is to provide an arc chute assembly for improved arc quenching in electric switching device which enables effective and quick arc extinction.
Yet another object of the present invention is to provide an arc chute assembly for improved arc quenching in electric switching device which is cost effective.
Still another object of the present invention is to increase the magnetic permeability of arc chute plates.
Yet another object of the present invention is to prevent the interaction of the ions between different phases and reduce the chances of phase to phase short circuit.

SUMMARY OF INVENTION
According to this invention there is provided an arc chute assembly for improved arc quenching in electric switching device comprising a housing accommodating an arc chute of a plurality of ferromagnetic plates maintaining a gap therebetween, wherein a deionization chamber is placed above the plates so as to obtain high permeable ferromagnetic plates.
BRIEF DESCRIPTION QF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings of exemplary embodiments of invention and wherein:
Fig. I shows:Side elevation of an arc chute assembly to increase magnetic
permeability of arc chute plates according to present invention.
Fig. 2 shows:Cross-section on the line i of figure 1 to indicate ferromagnetic
olate.
DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING DRAWINGS '
The present invention makes a disclosure regarding an arc chute assembly for improved are quenching in electric switching device. In respect of this, reference may be made to fig 1. The arc chute assembly includes a housing accommodating arc chute. The arc chute comprises a plurality of de-

ion/splitter plates (1) placed vertically by securing to said housing. The plates made of ferromagnetic material maintain a gap therebetween as illustrated.
An exemplary embodiment of the ferromagnetic plate is shown in fig 2. The plate, one side of which forms substantially a rectangular section with a flange (K) at both ends directing away from each other. The other side (E) of the plate is having a substantially inverted V slot. The flange ends are supported on side walls of the housing to suspend the plate between the side walls. Alternatively, a plate of any shape may be adopted possibly without slot. However the plate with slot is preferred. The housing is made of insulating material with high dielectric strength such as dough molding compound (DMC), sheet molding compound (SMC).
There is provision of arc protector (2) in proximity to the fixed contact. Said protector comprises a platewhich is bent at one end and directed towards bottom of the housing. This plate prevents movement of arc. Thus it acts as a boundary wall for the arc to prevent its movement beyond the same.
When an arc is drawn or enters the lower end of the plates (1) transversely in the region of lower open ends (10) of the slots, the arc is drawn up the slots by magnetic interaction with the Ferro-magnetic plates (1) and is forced up to the closed ends (6) of the slots. The arc is forced to assume a zig-zag shape, extending around the edges of the slots (11) between adjacent.plates (12). The arc is correspondingly lengthened and simultaneously cooled unit it is eventually extinguished. Thus, the arc extinction is achieved by effective lengthening of the plates (9) followed by cooling without reducing the cross section of the arc profoundly.
There is placement of a deionization chamber (7) above the chute plates (1) in which de-ionization of gases takes place prior to dissipation of the gases through a vent (8).

Above the chamber, a wire mesh (4) is located so as to trap the ions within the chamber (7). This wire mesh prevents the ions to pass through the vent which in turn avoids the possibility of interaction of ions of adjacent phases, thereby preventing phase to phase short circuit.
In addition to the above, the Ferro-magnetic plates (5) above the wire meshreinforces the. function of wire mesh to retain all the ions inside.
The arc chute assembly of invention is implemented to obtain high permeable ferromagnetic plates by decarburization of ferromagnetic plates. The high permeable ferromagnetic plates arefurther subjected to coating of a material such as Copper, Nickel without restricting scope of the invention to the same. Thus. other suitable materials which can withstand high temperatures when the arc travels up the plates, which are readily apparent to a person skilled in the art are understood to be within purview of the invention.
The coated high permeable ferromagnetic plate thus obtained are employed in a switching device to reduce arc quenching time.
Thus, the present invention provides an arc chute assembly having arc chute plates in such a way that it effectively lengthens the arc and deionizesit in the chamber above the plates. In order to achieve quick arc extinction in low voltage circuit breakers the plates are decarbonized to increase the magnetic permeability thereof followed by coating.

The application of the instant invention can be extended to any type of electrical switching devices such as MCB, MGCB, ACB,Contractor etc.
It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:-

WE CLAIM:
1. An arc chute assembly for improved arc quenching in electric switching device comprising a housing accommodating an arc chute of a plurality of ferromagnetic plates maintaining a gap therebetween, wherein a deionization chamber is placed above the plates so as to obtain high permeable ferromagnetic plates.
2. An arc chute assembly for improved arc quenching in electric switching device as claimed in claim 1 wherein the vertically suspended plates are secured to the housing walls by means of both flange ends at one side of each of the plates, other side of which is provided with a substantially inverted V-slot to accommodate arc.
3. An arc chute assembly for improved arc quenching in electric switching device as claimed in claim 1 or 2 wherein the plates can be of any shape such as rectangular, square possibly without slot.
4. An arc chute assembly for improved arc quenching in electric switching deviceas claimed in any of the proceeding claims whereinthe housing is made of insulating material with high dielectric strength.
5. An arc chute assembly for improved arc quenching in electric switching device as claimed in any of the proceeding claims comprises an arc protector including a plate in proximity to the fixed contact which is bent at one end and directed towards bottom of the housing to prevent movement of the arc.
6. An arc chute assembly for improved arc quenching in electric switching device as claimed in any of the proceeding claims wherein thearc is forced to assume a zig-zag shape, extending around the edges of the slots between adjacent plates wherein the arc is correspondingly lengthened and simultaneously cooled until it is finally extinguished.

7. An arc chute assembly for improved arc quenching in electric switching device as claimed in any of the proceeding claims wherein de-ionization of gases takes place in the deionization chamber prior to dissipation of the gases through a vent.
8. An arc chute assembly for improved arc quenching in electric switching device as claimed in any of the proceeding claims wherein a wire mesh is located above said deionization chamber to trap the ions within the chamber.
9. An arc chute assembly for improved arc quenching in electric switching device as claimed in any of the proceeding claims wherein the wire mesh is mounted with ferro-magnetic plates there above to reinforce the functionality of wire mesh.
10. An arc chute assembly for improved arc quenching in electric
switching device as claimed in any of the proceeding claims wherein the
high permeable ferromagnetic plates are coated with a material such as
Copper, Nickel which can withstand high temperature when the arc
travels up the plates.