Title of Invention

AN ELECTRICAL CIRCUIT BREAKER

Abstract A circuit breaker housed comprises an insulating enclosure equipped with a shield 48 arranged between the rotary base 29 of the handle 18 and the intermediate compartment 36 of the electromagnetic trip device, to prevent any projection of ionized gases through the orifice 27 of the front panel during the arc extinguishing phase. The shield comprises a first separating partition 44A moulded with the case 10A and a second separating partition 44B moulded with the cover 10B, said first and second partitions coming into abutment with one another when the cover 10B is adjoined against the case 10A. The first partition 44A extends between the front panel 28 and a protuberance 46 associated to the insulating support lever 34 of the movable contact arm 32, said protuberance cooperating in the open position with the first partition 44A to achieve continuity of the shield 48. The second partition 44B of the cover 10B is arranged between the front panel 28 and the pivoting support plate 16 of the operating mechanism 14.
Full Text

AN ELECTRICAL CIRCUIT BREAKER WITH A SAFETY SHIELD
The invention relates to an electrical circuit breaker housed in an enclosure made of moulded insulating material, composed of a case and a cover in the form of half-shells coming into engagement with one another at the level of an assembly interface and bounding inside :
- an upper compartment housing a handle and an operating mechanism with a pivoting support plate to drive a movable contact arm, said handle protruding out from the enclosure via an orifice arranged in the front panel, and being on the other hand mechanically connected to the plate by a transmission rod,
- recesses provided near to the opposite side faces of the enclosure to receive two connection terminals,
- a central part subdivided into an intermediate compartment for fitting of an electromagnetic trip device and a bottom compartment housing an arc extinguishing chamber,
- and an exhaust orifice for outlet of the breaking gases when extinguishing of the arc takes place in said chamber.
The exhaust orifice is generally arranged in the bottom panel or on one of the side faces at the outlet of the arc extinguishing chamber.
The different compartments inside the insulating enclosure of the circuit breaker are

not separated from one another tightly. In the event of breaking of a short-circuit current, the high pressure inside the enclosure may give rise to leakages of ionized gases via the orifice of the handle, to the detriment of safety of the persons near to the front panel of the circuit breaker.
The object of the invention is to achieve an electrical circuit breaker guaranteeing total safety of people regardless of the intensity of the current to be interrupted.
The circuit breaker according to the invention is characterized in that the enclosure is equipped in addition with a shield arranged between the rotary base part of the handle and the intermediate compartment to prevent any projection of ionized gases through the orifice of the front panel during the arc extinguishing phase.
According to a preferred embodiment, the shield is formed by a first separating partition moulded with the case, and a second separating partition moulded with the cover, said first and second partitions coming into abutment with one another when the cover is adjoined against the case.
The first partition extends between the front panel and a protuberance associated to the insulating support lever of the movable contact arm, said protuberance cooperating in the open position with the first partition to achieve continuity of the shield. The second partition of the cover is arranged between the front panel and the pivoting support plate of the operating mechanism.
Other advantages and features will become more clearly apparent from the following

description of an embodiment of the invention given as a non-restrictive example only and represented in the accompanying drawings in which :
- Figure 1 shows a perspective view of the case of the enclosure housing the circuit breaker operating mechanism.
- Figure 2 shows a perspective view of the cover designed to be fitted onto the case of figure 1 to constitute the insulating enclosure.
- Figure 3 is an elevational view of figure 1 in the closed position of the circuit breaker,
- Figure 4 is an identical view to figure 3 in the open position of the circuit breaker,
- Figure 5 is a view of the case with the circuit breaker fully equipped.
- Figure 6 shows a view of the cover fitting onto the case of figure 5.
With reference to figures 1 and 2, an electrical circuit breaker 10 is housed in an enclosure made of moulded insulating material composed by assembly of a lower case 10A and an upper cover 10B in the form of half-shells coming into engagement with one another at the level of the assembly interface 12. The case 10A (figure 1) supports an operating mechanism 14 with a pivoting support plate 16 connected to the handle 18 by a transmission rod 20, The internal face of the case 10A is equipped with a plurality of ribs or walls designed to cooperate with adjacent ribs of the cover 10B to define a series of elementary compartments inside the enclosure.

The opposite side faces of the case 10A and cover 10B comprise recesses 22A, 22B; 24A, 24B receiving the connection terminals, A longitudinal partition 26A, 26B extends at the base of the case 10A and of the cover 10B to form the bottom of the enclosure.
The handle 18 protrudes out from an orifice 27 arranged in the front panel 28 of the enclosure, and comprises a base part 29 pivotally mounted on a spindle 30 moulded with the case 10A. The operating mechanism 14 is described as an example in the document EP-A-295,158, and drives the movable contact arm 32 between the closed position and the open position following manual actuation or automatic tripping. The support plate 16 is mounted with limited rotation on a pivot 33 securedly affixed to the cover10B.
The movable contact arm 32 is securedly affixed to a support lever 34 made of insulating material borne by the support plate 16 with interposed flexible means (not represented) allowing a relative movement suitable for contact pressure in the closed position. The mechanism 14 is arranged in the upper compartment of the enclosure on the same side as the front face 28.
The central part of the enclosure is subdivided into an intermediate compartment 36 designed for fitting the electromagnetic trip device (not represented) and a lower compartment 38 containing the arc extinguishing chamber (not represented). A perforated wall 4OA, 4OB separates the lower compartment 38 from the recesses 22A, 22B, and allows the breaking gases to escape to an exhaust orifice 42A, 42B provided in the partition 26A, 26B of the bottom plate, opposite the orifice 27 housing

the base part 29 of the handle 18.
The rotary base part 29 of the handle 18 is separated from the intermediate compartment 36 by a pair of fixed partitions 44A, 44B moulded with the case 10A and the cover 10B. The separating partition 44A associated to the case 10A extends between the front panel 28 and a protuberance 46 of the contact-bearing support lever 34. The other separating partition 44B associated to the cover 10B is arranged between the front panel 28 and the rotary support plate 16 of the mechanism.
When the case 10A and cover 10B are adjoined at the end of the circuit breaker assembly operation, the two fixed partitions 44A, 44B come into abutment with one another and cooperate respectively with the protuberance 46 of the contact-bearing support lever 34 and with the plate 16 to form in the open position a tight shield 48 between the intermediate compartment 36 and the base part 29 of the handle 18. During extinguishing of the arc in the arc extinguishing chamber, the presence of the shield 48 prevents any risk of external projection of ionized gases via the orifice 27 of the front panel. Outlet of the breaking gases is achieved entirely by the exhaust orifices 42A, 42B at the level of the bottom panel of the insulating enclosure.
Figures 3 and 4 show the arrangement of the shield 48 according to the closed or open state of the circuit breaker 10 :
In figure 3, the movable contact arm 32 is in the closed position and the handle 18 is situated in the first end of travel position, at the right-hand end of the orifice 27. The protuberance 46 of the support lever 34 is offset from the end of the separating

partition 44A leaving a gap 50 between the intermediate compartment 36 and the base part 29. The presence of this gap 50 is not troublesome when the circuit breaker is in the closed state in the absence of a fault.
In case of tripping of the mechanism 14 following detection of a short-circuit current, the movable contact arm 32 separates from the stationary contact with appearance of an arc which is deionized and extinguished in the extinguishing chamber of the bottom compartment 38. At the end of opening travel (figure 4), the support plate 16 and lever 34 have pivoted a certain angle counterclockwise and the protuberance 46 is positioned facing the fixed partition 44A in such a way as to bound the shield 48. Blanking the gap 50 off enables a continuity of the shield to be obtained between the intermediate compartment 36 and the base part 29 of the handle 18, which prevents any emission or outlet of ionized gases via the orifice 27 of the front panel 28.
Figure 5 shows the set of parts of the circuit breaker 10 after assembly inside the case 10A. The electromagnetic trip device 54 is arranged in the intermediate compartment 36 and the arc extinguishing chamber 56 is placed in the bottom compartment 38 with the arc guiding cheeks 58. One of the ends of the coil of the electromagnetic trip device 54 is connected to a connection terminal 60 inserted in the recess 22A whereas the other end of the coil is connected to the stationary contact 62 cooperating with the movable contact arm 32. The latter is electrically connected by a braid (not represented) to a bimetal strip 64 of a thermal trip device in electrical connection with the connection terminal 66 situated in the opposite recess 24A,
It can be noted that the shield formed by the partition 44B and protuberance 46 is

inserted between the electromagnetic trip device 54 and the base part 29 of the handle 18.
Figure 6 represents an elevational view of the cover 10B designed to be fitted onto the case 10A to form the insulating enclosure of the circuit breaker 10. The separating partition 44B is arranged between the intermediate compartment 36 and the upper compartment 68 housing the base part of the handle 18.




CLAIMS
1. An electrical circuit breaker housed in an enclosure made of moulded insulating material, composed of a case (10A) and a cover (10B) in the form of half-shells coming into engagement with one another at the level of an assembly interface (12) and bounding inside :
- an upper compartment (68) housing a handle (18) and an operating mechanism (14) with a pivoting support plate (16) to drive a movable contact arm (32), said handle (18) protruding out from the enclosure via an orifice (27) arranged in the front panel (28), and being on the other hand mechanically connected to the plate (16) by a transmission rod (20),
- recesses (22A, 22B; 24A, 24B) provided near to the opposite side faces of the enclosure to receive two connection terminals (60, 66),
- a central part subdivided into an intermediate compartment (36) for fitting of an electromagnetic trip device (54) and a bottom compartment (38) housing an arc extinguishing chamber (56),
- and an exhaust orifice (42A, 42B) for outlet of the breaking gases when
extinguishing of the arc takes place in said chamber (56),
characterized in that the enclosure is equipped in addition with a shield (48) arranged between the rotary base part (29) of the handle (18) and the intermediate compartment (36) to prevent any projection of ionized gases through the orifice (27)

of the front panel (28) during the arc extinguishing phase,
2. The electrical circuit breaker according to claim 1, characterized in that the shield (48) is formed by a first separating partition (44A) moulded with the case (10A), and a second separating partition (44B) moulded with the cover (10B), said first and second partitions (44A, 44B) coming into abutment with one another when the cover (10B) is adjoined against the case (10A).
3. The electrical circuit breaker according to claim 1, characterized in that the first partition (44A) extends between the front panel (28) and a protuberance (46) associated to the insulating support lever (34) of the movable contact arm (32), said protuberance cooperating in the open position with the first partition (44A) to achieve continuity of the shield (48).
4. The electrical circuit breaker according to claim 2 or 3, characterized in that the second partition (44B) of the cover (10B) is arranged between the front panel (28) and the pivoting support plate (16) of the operating mechanism (14).
5. The electrical circuit breaker according to one of the claims 1 to 4, characterized in that the exhaust orifice (42A, 42B) is situated opposite the orifice (27) housing the base part (29) of the handle (18).

6• An electrical circuit breaker housed in an enclosure made of moulded insulating material, substantially as herein described with reference to the accompanying drawings*


Documents:

2786-mas-1997-abstract.pdf

2786-mas-1997-claims filed.pdf

2786-mas-1997-claims granted.pdf

2786-mas-1997-correspondnece-others.pdf

2786-mas-1997-correspondnece-po.pdf

2786-mas-1997-description(complete)filed.pdf

2786-mas-1997-description(complete)granted.pdf

2786-mas-1997-drawings.pdf

2786-mas-1997-form 1.pdf

2786-mas-1997-form 26.pdf

2786-mas-1997-form 3.pdf

2786-mas-1997-other documents.pdf

abs-2786-mas-1997.jpg


Patent Number 212460
Indian Patent Application Number 2786/MAS/1997
PG Journal Number 07/2008
Publication Date 15-Feb-2008
Grant Date 03-Dec-2007
Date of Filing 05-Dec-1997
Name of Patentee SCHNEIDER ELECTRIC SA
Applicant Address 40 AVENUE ANDRE MORIZET -F 92100, BOULOGNE BILLANCOURT,
Inventors:
# Inventor's Name Inventor's Address
1 YVES BELIN LIEUDIT LA PRA-F 38320 HERBEYS,
2 JEAN-CLAUDE USE AVENUE DU VERCORS-F 38420 MEYLAN,
PCT International Classification Number H 01 H 33/02
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA