Title of Invention	CURRENT LIMITING CONTACT SYSTEM
Abstract	The present invention relates to a current limiting contact system. The system comprises cassette (1), conducting bar means (24, 28) being operatively disposed in plurality of chambers (13, 27) provided in cassette (1) so that bar means (24, 28) are movable inside chamber (13, 27) having appropriate clearance in a predetermined central plane. Plurality of contact means (7, 8) are suitably located on the bar means (24, 28) and plurality of loop means (2, 16) are accommodated in said chambers (13, 27) comprising an aperture (12, 25) so as to operatively dispose conducting bar means (24, 28). Loop means (2, 16) being profiled so as to generate strong magnetic field and plurality of plate means (20) being operatively places in the loop means (2, 16) for achieving strong magnetic field and strong blow-out field.

Title of Invention

CURRENT LIMITING CONTACT SYSTEM

Abstract

The present invention relates to a current limiting contact system. The system comprises cassette (1), conducting bar means (24, 28) being operatively disposed in plurality of chambers (13, 27) provided in cassette (1) so that bar means (24, 28) are movable inside chamber (13, 27) having appropriate clearance in a predetermined central plane. Plurality of contact means (7, 8) are suitably located on the bar means (24, 28) and plurality of loop means (2, 16) are accommodated in said chambers (13, 27) comprising an aperture (12, 25) so as to operatively dispose conducting bar means (24, 28). Loop means (2, 16) being profiled so as to generate strong magnetic field and plurality of plate means (20) being operatively places in the loop means (2, 16) for achieving strong magnetic field and strong blow-out field.

Full Text	FORM2 THE PATENTS ACT, 1970 (39 of 1970) & The Patents Rules, 2003 COMPLETE SPECIFICATION (See section 10; rule 13) 1. Title of the invention. - CURRENT LIMITING CONTACT SYSTEM 2. Applicant (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: FIELD OF INVENTION The present invention relates to a current limiting contact system. More particularly, the invention relates to a current limiting contact system for achieving strong magnetic field for moving contact and strong blow-out field for arc at the time of short circuit to clear the short circuit fault rapidly. BACKGROUND AND PRIOR ART A current limiting circuit breaker should clear fault as fast as possible so that let through energy passing to the connected downstream devices can be minimized and connected downstream devices remain safe from thermal stresses due to this let through energy passed. At the same time a current limiting circuit breaker also limits the fault current as low as possible so that connected downstream devices do not come under stresses due to high magnetic force because of this high magnitude limited current. Magnetic field in contact region and blow out field are some of the main factors contributing to clear the short circuit fault as fast as possible. In DE19629867 two parallel rails 33 and 34 are making two U-shaped parallel loops. Two parallel rails 40 and 41 are making two L-shaped parallel loops. U-shaped loops 33 and 34 are connected by 35 and 36 and L-shaped loops 40 and 41 are connected by 42 and 43. Part 36 and part 42 are connected by rotary bar 39 and 46. If we suppose that current enters from part 35 then arrows in part 35, part 33, part 34, part 36, part 39, part 46, part 42, part 40, part 41 and part 43 are showing the direction of the current in contact system. 2 Rotary bar 39 and 46 move in central plane. This central plane is that plane which bisects the distance between part 33 and part 34 and the same central plane also bisects the distance between 40 and 41. Part 33 and part 34 are having an offset from this central plane and part 40 and 41 also have an offset from central plane. Rotary bar 39 interacts with magnetic field created by part 33 and part 34 at the central plane. Rotary bar 46 interacts with magnetic field created by part 40 and part 41. At the time of short circuit, current in rotary bar 39 and magnetic field, created by part 33 and part 34 at central plane, interacts and clears the fault. Current in rotary bar 46 interacts with magnetic field created by part 40 and part 41at central plane and clears the fault. U-shaped loops and L-shaped loops have an offset from the central plane and because of this offset magnetic field strength at central plane decreases. The present invention doesn't make offset loops and the magnetic field strength at the central plane is more than DE19629867. Thus there is a need to provide for a current limiting contact system so as to achieve strong magnetic field for moving contact and strong blow-out field for arc at the time of short circuit to clear the short circuit fault rapidly. The present inventors have now found that strong magnetic field for moving contact and strong blow-out field for arc at the time of short circuit to clear the short circuit fault can be achieved by a unique design of a loop means carrying current being operatively combined to movable means. 3 OBJECTS OF INVENTION Thus one object of the present invention is to provide a current limiting contact system to achieve strong magnetic field for moving contacts. Another object of the present invention is to provide a current limiting contact system to provide for strong blowout field. Another object of the present invention is to clear the short circuit fault rapidly. SUMMARY OF INVENTION Thus according one aspect of the present invention there is provided a current limiting contact system comprising : cassette; conducting bar means being operatively disposed in plurality of chambers provided in cassette, said conducting bar means being movable inside said chamber having appropriate clearance in a predetermined central plane; plurality of contact means suitably located on said bar means; plurality of loop means being accommodated in said chambers comprising an aperture so as to operatively dispose conducting bar; wherein said loop means being profiled so as to generate strong magnetic field; and plurality of plate means being operatively placed in said loop means 4 for achieving strong magnetic field and strong blow-out field. DETAILED DESCRIPTION OF INVENTION The contact system of the present invention comprises cassette having two chambers which are bridged by conducting bar. The bar has two moving parts each of which are disposed in the two chambers in a predetermined manner. The intermediate part the bridging conducting bar which lies between the two moving parts is housed in a driving shaft. The moving part comprises moving contact button means and fixed contact button means are fixed on loop means (herein described as current carrying fixed contact loop) . Just next to the fixed contact button an arc runner is assembled on current carrying fixed contact loop. Current carrying fixed contact loop employs arc chute, moving contact and moving part as described above. The current carrying fixed contact loop means comprises a U-shape profile of appropriate width such that the conducting bar means are able to move at high speed along the central plane bisecting the loop. The loop is beveled at appropriate locations. In another embodiment of the present invention an insulating shield means is provided to current carrying fixed contact loop so that at the time of short circuit current carrying loop does not get exposed to the arc. Deion plates means are arranged in such a way that these deion plates direct ionized gases to the outside chamber with the help of an exit. A cut / aperture is provided in current carrying fixed contact loop so that moving contact 5 can pass through this cut / aperture. Insulating cover means is provided between current carrying fixed contact loop and moving part so that the moving part is prevented to be exposed to current carrying fixed contact loop. Second current carrying fixed contact loop is housed in the other chamber. Fixed contact button is assembled on current carrying fixed contact loop and just next to fixed contact button an arc runner is also fixed on the current carrying fixed contact loop. In another embodiment of the present invention moving contact button and moving part rotate in a central plane. Because of the profile of current carrying fixed contact loop as described above a strong magnetic field B is created at central plane. Moving contact button and moving part move in central plane and because of the strong magnetic field moving parts open with high speed and blow out forces on the arc are also very high at the time of short circuit. BRIEF DESCRIPTION OF ACCOMPANYING FIGURES Figure 1 illustrates a perspective view of opened cassette and this cassette is employing contact system of the present invention. Figure 2 illustrates a perspective compressed view of Figure 1 and showing only contact system arrangement with other entities hidden of the present invention. Figure 3 shows front view of Figure 2 of the present invention. 6 Figure 4 illustrates an exploded view of the cassette assembly of the present invention. Figure 5 illustrates completely closed cassette of the present invention. Figure 6 shows prior art figure. DETAILED DESCRIPTION OF ACCOMPANYING FIGURES In figure 1 a perspective view of opened cassette and this cassette is employing contact system of the present invention is illustrated. Cassette 1 can have one or two chambers (construction wise same) and each chamber has one fixed loop contact and one moving contact. The said fixed loop contact partially encircles the moving contact. If cassette 1 has two chambers then moving contacts of both the chambers are interconnected. In the shown diagrams, cassette 1 has two chambers and moving contact of both the chambers are connected. The said two chambers in cassette 1 are chamber 13 and chamber 27. Chamber 13 and chamber 27 are bridged by conducting bar. A part (moving part) 28 of the bridging conducting bar moves in chamber 13 and another part (moving part) 24 of the same bridging conducting bar moves in chamber 27. Part of conducting bar, which lies between part 28 and part 24, is housed in the driving shaft 14. Moving contact button 8 is assembled on moving part 28 and moving contact button 23 is assembled on moving part 24. Fixed contact button 7 is fixed on current carrying fixed contact loop 2 and just next to fixed contact button 7 an arc runner 6 is assembled on current carrying fixed contact loop 2. Current carrying fixed contact loop 2 7 employs arc chute 4, moving contact 8 and moving part 28. An insulating shield 9 is provided to current carrying fixed contact loop 2 so that at the time of short circuit current carrying loop 2 doesn't get exposed to the arc. Deion plates 5 are arranged in such a way that these deion plates 5 direct ionized gases to the outside chamber 13 with the help of exit 3. A cut 12 is provided in current carrying fixed contact loop 2 so that moving contact 28 can pass through this cut 12. An insulating cover 10 is put between current carrying fixed contact loop 2 and moving part 28 so that the moving part 28 doesn't get exposed to current carrying fixed contact loop 2. Second current carrying fixed contact loop 16 is housed in chamber 27. Fixed contact button 22 is assembled on current carrying fixed contact loop 16 and just next to fixed contact button 22 an arc runner 21 is also fixed on the current carrying fixed contact loop 16. Current carrying fixed contact loop 16 employs arc chute 19, moving contact button 23 and moving part 24. An insulating shield 17 is provided to current carrying fixed contact loop 16 so that arc doesn't get exposed to current carrying fixed contact loop 16. A cut 25 is provided in current carrying fixed contact loop 16 so that moving part 24 can pass through this cut 25. An insulating cover 15 is provided between current carrying fixed contact loop 16 and moving part 24 so that moving part 24 doesn't get exposed to current carrying fixed contact loop 16. Deion plates 20 are arranged in such a way that these deion plates 20 direct ionized gases to outside chamber 27 with the help of exit 18. Rivets 26 are provided so that cover (not shown) can be riveted with cassette 1. 8 In figure 2 a perspective compressed view of Figure 1 and showing only contact system arrangement with other entities hidden of the present invention is illustrated. Only contact system is shown here. Moving contact button 8, moving contact button 23, moving part 28 and moving part 24 rotate in a central plane. This central plane bisects the width of current carrying fixed contact loop 2 and current carrying fixed contact loop 16. The profile of current carrying fixed contact loop 2 and 16 is such that they create strong magnetic field at central plane. In figure 3 front view of figure 2 of the present invention is illustrated. Arrows in current carrying fixed contact loop 2, current carrying fixed contact loop 16, moving part 28 and moving part 24 are showing the direction of current flow in contact system if we are supposing that source is pumping current into current carrying fixed contact loop 2. Because of the profile of current carrying fixed contact loop 2 and 16 a strong magnetic field B is created at central plane. Moving part 28, moving contact button 8, moving contact button 23 and moving part 24 move in central plane and because of the strong magnetic field B moving part 24 and 28 open with high speed and blow out forces on the arc are also very high at the time of short circuit. In figure 4 an exploded view of the cassette assembly of the present invention is illustrated. An exploded view of assembly of cassette 1 is shown here. Cover 29 closes the cassette 1 and this cover 29 is riveted with cassette 1. Cut 30 in cover 29 is provided for slot motor assembly and same cut as cut 30 is also provided in the backside of cassette 1. These cut 30 also act as pressure builders and 9 increase the pressure in chamber 13 and 27. This high pressure supports in the act of extinguishing of arc at the time of short circuit. In figure 5 completely closed cassette of the present invention is illustrated. A completely closed cassette is shown here and cover 29 is fixed with cassette 1 with the helps of rivets 26 (not shown). The invention has been described in a preferred form only and many variations may be made in the invention which will still be comprised within its spirit. The invention is not limited to the details cited above. The components and designs as herein used can be replaced by its technical equivalence and yet the invention can be performed. The structure thus conceived is susceptible of numerous modifications and variations, all the details may furthermore be replaced with elements having technical equivalence. In practice the materials and dimensions may be any according to the requirements, which will still be comprised within its true spirit. 10 WE CLAIM 1. A current limiting contact system comprising : cassette; conducting bar means being operatively disposed in plurality of chambers provided in cassette, said conducting bar means being movable inside said chamber having appropriate clearance in a predetermined central plane; plurality of contact means suitably located on said bar means; plurality of loop means being accommodated in said chambers comprising an aperture so as to operatively dispose conducting bar; wherein said loop means being profiled so as to generate strong magnetic field; and plurality of plate means being operatively placed in said loop means for achieving strong magnetic field and strong blowout field. 2. System as claimed in claim 1, wherein loop means comprise current carrying fixed contact loops. 3. System as claimed in claims 1 and 2, wherein current carrying fixed contact loop means comprises a U-shape profile of appropriate width such that the conducting bar means are able to move at high speed along the central plane bisecting the loop means. 11 4. System as claimed in claim 3, wherein the current carrying fixed contact loop comprises beveled surfaces located appropriately adapted to generate suitable direction of current so as to produce strong magnetic field. 5. System as claimed in claims 1 to 4, wherein current carrying fixed contact loop means further comprises of a predetermined exit. 6. System as claimed in claims 1 to 4, wherein the plate means comprises deion plates such that it directs deionized gases at high pressure through the exit of the loop means into the chambers thereby suppressing the arc. 7. System as claimed in claim 1, wherein the cassette comprises suitable cut adapted to increase the pressure inside the chambers. 8. A current limiting contact system as herein substantially described and illustrated with reference to the accompanying figures. Dated this 18th day of December 2006. ; .---, -/'//' V./ •-,.., , .i Ci.i 1.';-u A. ~-'Y ; i, Abhishek Sen Of S. Majumdar & Co. Applicant's Agent 12 ABSTRACT TITLE : CURRENT LIMITING CONTACT SYSTEM The present invention relates to a current limiting contact system. The system comprises cassette (1), conducting bar means (24, 28) being operatively disposed in plurality of chambers (13, 27) provided in cassette (1) so that bar means (24, 28) are movable inside chamber (13, 27) having appropriate clearance in a predetermined central plane. Plurality of contact means (7, 8) are suitably located on the bar means (24, 28) and plurality of loop means (2, 16) are accommodated in said chambers (13, 27) comprising an aperture (12, 25) so as to operatively dispose conducting bar means (24, 28). Loop means (2, 16) being profiled so as to generate strong magnetic field and plurality of plate means (20) being operatively placed in the loop means (2, 16) for achieving strong magnetic field and strong blow-out field. Figure 1

Full Text

FORM2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title of the invention. - CURRENT LIMITING CONTACT SYSTEM
2. Applicant
(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:

FIELD OF INVENTION
The present invention relates to a current limiting contact system. More particularly, the invention relates to a current limiting contact system for achieving strong magnetic field for moving contact and strong blow-out field for arc at the time of short circuit to clear the short circuit fault rapidly.
BACKGROUND AND PRIOR ART
A current limiting circuit breaker should clear fault as fast as possible so that let through energy passing to the connected downstream devices can be minimized and connected downstream devices remain safe from thermal stresses due to this let through energy passed. At the same time a current limiting circuit breaker also limits the fault current as low as possible so that connected downstream devices do not come under stresses due to high magnetic force because of this high magnitude limited current. Magnetic field in contact region and blow out field are some of the main factors contributing to clear the short circuit fault as fast as possible.
In DE19629867 two parallel rails 33 and 34 are making two U-shaped parallel loops. Two parallel rails 40 and 41 are making two L-shaped parallel loops. U-shaped loops 33 and 34 are connected by 35 and 36 and L-shaped loops 40 and 41 are connected by 42 and 43. Part 36 and part 42 are connected by rotary bar 39 and 46. If we suppose that current enters from part 35 then arrows in part 35, part 33, part 34, part 36, part 39, part 46, part 42, part 40, part 41 and part 43 are showing the direction of the current in contact system.
2

Rotary bar 39 and 46 move in central plane. This central plane is that plane which bisects the distance between part
33 and part 34 and the same central plane also bisects the distance between 40 and 41. Part 33 and part 34 are having an offset from this central plane and part 40 and 41 also have an offset from central plane. Rotary bar 39 interacts with magnetic field created by part 33 and part 34 at the central plane. Rotary bar 46 interacts with magnetic field created by part 40 and part 41. At the time of short circuit, current in rotary bar 39 and magnetic field, created by part 33 and part
34 at central plane, interacts and clears the fault. Current in rotary bar 46 interacts with magnetic field created by part 40 and part 41at central plane and clears the fault. U-shaped loops and L-shaped loops have an offset from the central plane and because of this offset magnetic field strength at central plane decreases. The present invention doesn't make offset loops and the magnetic field strength at the central plane is more than DE19629867.
Thus there is a need to provide for a current limiting contact system so as to achieve strong magnetic field for moving contact and strong blow-out field for arc at the time of short circuit to clear the short circuit fault rapidly.
The present inventors have now found that strong magnetic field for moving contact and strong blow-out field for arc at the time of short circuit to clear the short circuit fault can be achieved by a unique design of a loop means carrying current being operatively combined to movable means.
3

OBJECTS OF INVENTION
Thus one object of the present invention is to provide a current limiting contact system to achieve strong magnetic field for moving contacts.
Another object of the present invention is to provide a current limiting contact system to provide for strong blowout field.
Another object of the present invention is to clear the short circuit fault rapidly.
SUMMARY OF INVENTION
Thus according one aspect of the present invention there is provided a current limiting contact system comprising :
cassette;
conducting bar means being operatively disposed in plurality
of chambers provided in cassette, said conducting bar means
being movable inside said chamber having appropriate
clearance in a predetermined central plane;
plurality of contact means suitably located on said bar
means;
plurality of loop means being accommodated in said chambers
comprising an aperture so as to operatively dispose
conducting bar;
wherein said loop means being profiled so as to generate
strong magnetic field; and
plurality of plate means being operatively placed in said
loop means
4

for achieving strong magnetic field and strong blow-out field.
DETAILED DESCRIPTION OF INVENTION
The contact system of the present invention comprises cassette having two chambers which are bridged by conducting bar. The bar has two moving parts each of which are disposed in the two chambers in a predetermined manner. The intermediate part the bridging conducting bar which lies between the two moving parts is housed in a driving shaft. The moving part comprises moving contact button means and fixed contact button means are fixed on loop means (herein described as current carrying fixed contact loop) . Just next to the fixed contact button an arc runner is assembled on current carrying fixed contact loop. Current carrying fixed contact loop employs arc chute, moving contact and moving part as described above. The current carrying fixed contact loop means comprises a U-shape profile of appropriate width such that the conducting bar means are able to move at high speed along the central plane bisecting the loop. The loop is beveled at appropriate locations.
In another embodiment of the present invention an insulating shield means is provided to current carrying fixed contact loop so that at the time of short circuit current carrying loop does not get exposed to the arc. Deion plates means are arranged in such a way that these deion plates direct ionized gases to the outside chamber with the help of an exit. A cut / aperture is provided in current carrying fixed contact loop so that moving contact
5

can pass through this cut / aperture. Insulating cover means is provided between current carrying fixed contact loop and moving part so that the moving part is prevented to be exposed to current carrying fixed contact loop. Second current carrying fixed contact loop is housed in the other chamber. Fixed contact button is assembled on current carrying fixed contact loop and just next to fixed contact button an arc runner is also fixed on the current carrying fixed contact loop.
In another embodiment of the present invention moving contact button and moving part rotate in a central plane. Because of the profile of current carrying fixed contact loop as described above a strong magnetic field B is created at central plane. Moving contact button and moving part move in central plane and because of the strong magnetic field moving parts open with high speed and blow out forces on the arc are also very high at the time of short circuit.
BRIEF DESCRIPTION OF ACCOMPANYING FIGURES
Figure 1 illustrates a perspective view of opened cassette and this cassette is employing contact system of the present invention.
Figure 2 illustrates a perspective compressed view of Figure 1 and showing only contact system arrangement with other entities hidden of the present invention.
Figure 3 shows front view of Figure 2 of the present invention.
6

Figure 4 illustrates an exploded view of the cassette assembly of the present invention.
Figure 5 illustrates completely closed cassette of the present invention.
Figure 6 shows prior art figure.
DETAILED DESCRIPTION OF ACCOMPANYING FIGURES
In figure 1 a perspective view of opened cassette and this
cassette is employing contact system of the present
invention is illustrated. Cassette 1 can have one or two
chambers (construction wise same) and each chamber has one
fixed loop contact and one moving contact. The said fixed
loop contact partially encircles the moving contact. If
cassette 1 has two chambers then moving contacts of both
the chambers are interconnected. In the shown diagrams,
cassette 1 has two chambers and moving contact of both the
chambers are connected. The said two chambers in cassette 1
are chamber 13 and chamber 27. Chamber 13 and chamber 27
are bridged by conducting bar. A part (moving part) 28 of
the bridging conducting bar moves in chamber 13 and another
part (moving part) 24 of the same bridging conducting bar
moves in chamber 27. Part of conducting bar, which lies
between part 28 and part 24, is housed in the driving shaft
14. Moving contact button 8 is assembled on moving part 28
and moving contact button 23 is assembled on moving part
24. Fixed contact button 7 is fixed on current carrying
fixed contact loop 2 and just next to fixed contact button
7 an arc runner 6 is assembled on current carrying fixed
contact loop 2. Current carrying fixed contact loop 2
7

employs arc chute 4, moving contact 8 and moving part 28. An insulating shield 9 is provided to current carrying fixed contact loop 2 so that at the time of short circuit current carrying loop 2 doesn't get exposed to the arc. Deion plates 5 are arranged in such a way that these deion plates 5 direct ionized gases to the outside chamber 13 with the help of exit 3. A cut 12 is provided in current carrying fixed contact loop 2 so that moving contact 28 can pass through this cut 12. An insulating cover 10 is put between current carrying fixed contact loop 2 and moving part 28 so that the moving part 28 doesn't get exposed to current carrying fixed contact loop 2. Second current carrying fixed contact loop 16 is housed in chamber 27. Fixed contact button 22 is assembled on current carrying fixed contact loop 16 and just next to fixed contact button 22 an arc runner 21 is also fixed on the current carrying fixed contact loop 16. Current carrying fixed contact loop 16 employs arc chute 19, moving contact button 23 and moving part 24. An insulating shield 17 is provided to current carrying fixed contact loop 16 so that arc doesn't get exposed to current carrying fixed contact loop 16. A cut 25 is provided in current carrying fixed contact loop 16 so that moving part 24 can pass through this cut 25. An insulating cover 15 is provided between current carrying fixed contact loop 16 and moving part 24 so that moving part 24 doesn't get exposed to current carrying fixed contact loop 16. Deion plates 20 are arranged in such a way that these deion plates 20 direct ionized gases to outside chamber 27 with the help of exit 18. Rivets 26 are provided so that cover (not shown) can be riveted with cassette 1.
8

In figure 2 a perspective compressed view of Figure 1 and showing only contact system arrangement with other entities hidden of the present invention is illustrated. Only contact system is shown here. Moving contact button 8, moving contact button 23, moving part 28 and moving part 24 rotate in a central plane. This central plane bisects the width of current carrying fixed contact loop 2 and current carrying fixed contact loop 16. The profile of current carrying fixed contact loop 2 and 16 is such that they create strong magnetic field at central plane.
In figure 3 front view of figure 2 of the present invention is illustrated. Arrows in current carrying fixed contact loop 2, current carrying fixed contact loop 16, moving part 28 and moving part 24 are showing the direction of current flow in contact system if we are supposing that source is pumping current into current carrying fixed contact loop 2. Because of the profile of current carrying fixed contact loop 2 and 16 a strong magnetic field B is created at central plane. Moving part 28, moving contact button 8, moving contact button 23 and moving part 24 move in central plane and because of the strong magnetic field B moving part 24 and 28 open with high speed and blow out forces on the arc are also very high at the time of short circuit.
In figure 4 an exploded view of the cassette assembly of the present invention is illustrated. An exploded view of assembly of cassette 1 is shown here. Cover 29 closes the cassette 1 and this cover 29 is riveted with cassette 1. Cut 30 in cover 29 is provided for slot motor assembly and same cut as cut 30 is also provided in the backside of cassette 1. These cut 30 also act as pressure builders and
9

increase the pressure in chamber 13 and 27. This high pressure supports in the act of extinguishing of arc at the time of short circuit.
In figure 5 completely closed cassette of the present invention is illustrated. A completely closed cassette is shown here and cover 29 is fixed with cassette 1 with the helps of rivets 26 (not shown).
The invention has been described in a preferred form only and many variations may be made in the invention which will still be comprised within its spirit. The invention is not limited to the details cited above. The components and designs as herein used can be replaced by its technical equivalence and yet the invention can be performed. The structure thus conceived is susceptible of numerous modifications and variations, all the details may furthermore be replaced with elements having technical equivalence. In practice the materials and dimensions may be any according to the requirements, which will still be comprised within its true spirit.
10

WE CLAIM
1. A current limiting contact system comprising :
cassette;
conducting bar means being operatively disposed in plurality of chambers provided in cassette, said conducting bar means being movable inside said chamber having appropriate clearance in a predetermined central plane;
plurality of contact means suitably located on said bar means;
plurality of loop means being accommodated in said chambers comprising an aperture so as to operatively dispose conducting bar;
wherein said loop means being profiled so as to generate strong magnetic field; and
plurality of plate means being operatively placed in said loop means
for achieving strong magnetic field and strong blowout field.
2. System as claimed in claim 1, wherein loop means comprise current carrying fixed contact loops.
3. System as claimed in claims 1 and 2, wherein current carrying fixed contact loop means comprises a U-shape profile of appropriate width such that the conducting bar means are able to move at high speed along the central plane bisecting the loop means.
11

4. System as claimed in claim 3, wherein the current carrying fixed contact loop comprises beveled surfaces located appropriately adapted to generate suitable direction of current so as to produce strong magnetic field.
5. System as claimed in claims 1 to 4, wherein current carrying fixed contact loop means further comprises of a predetermined exit.
6. System as claimed in claims 1 to 4, wherein the plate means comprises deion plates such that it directs deionized gases at high pressure through the exit of the loop means into the chambers thereby suppressing the arc.
7. System as claimed in claim 1, wherein the cassette comprises suitable cut adapted to increase the pressure inside the chambers.
8. A current limiting contact system as herein substantially described and illustrated with reference to the accompanying figures.
Dated this 18th day of December 2006. ; .---,
-/'//' V./ •-,..,
, .i Ci.i 1.';-u A. ~-'Y ; i, Abhishek Sen Of S. Majumdar & Co. Applicant's Agent
12

ABSTRACT
TITLE : CURRENT LIMITING CONTACT SYSTEM
The present invention relates to a current limiting contact system. The system comprises cassette (1), conducting bar means (24, 28) being operatively disposed in plurality of chambers (13, 27) provided in cassette (1) so that bar means (24, 28) are movable inside chamber (13, 27) having appropriate clearance in a predetermined central plane. Plurality of contact means (7, 8) are suitably located on the
bar means (24, 28) and plurality of loop means (2, 16) are accommodated in said chambers (13, 27) comprising an aperture (12, 25) so as to operatively dispose conducting bar means (24, 28). Loop means (2, 16) being profiled so as to generate strong magnetic field and plurality of plate means (20) being operatively placed in the loop means (2, 16) for achieving strong magnetic field and strong blow-out field.
Figure 1

Documents:

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Patent Number

271136

Indian Patent Application Number

2089/MUM/2006

PG Journal Number

06/2016

Publication Date

05-Feb-2016

Grant Date

04-Feb-2016

Date of Filing

20-Dec-2006

Name of Patentee

LARSEN & TOUBRO LIMITED

Applicant Address

L & T HOUSE, BALLARD ESTATE, MUMBAI

Inventors:

#	Inventor's Name	Inventor's Address
1	JOSHI, AMEYA, S;	SWITCHGEAR DESIGN & PRODUCT DEVELOPMENT CENTER, LARSEN & TOUBRO LIMITED, ELECTRICAL SECTOR - (EBG), POWAI WORKS (EAST), GATE NO. 7, SAKI VIHAR ROAD, MUMBAI 400 072,

PCT International Classification Number

H01H77/10

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA