DESC:TECHNICAL FIELD

The present invention relates generally to a circuit breaker and, particularly, to single breaks moulded case circuit breaker modularity in components and connections involved in the architecture of the breaker.

BACKGROUND

A circuit breaker is a mechanical device which serves to making, breaking and carrying normal currents and making and breaking currents under specified abnormal circuit conditions such as that of a short circuit or overload.

Typically the circuit breaker consists of contact system, mechanism and current sensing unit. In a moulded case circuit breaker the arc quenching and fault clearing process takes place inside housing.

The contact system of the circuit breaker consists of fixed contacts and moving contact. During ON condition, a set of springs provide the contact force to maintain the moving contact in ON condition. The current conducts from the first fixed contact onto the moving contact and then onto the Heater/Terminal. The fixed and moving contacts are designed in such a way that during short circuit conditions, an electromagnetic force develops between these two. The electromagnetic torque acts against the spring torque and enables moving contact to open up and thus clear the fault. The moving contact with the spring arrangement is assembled inside a rotating chamber called shaft.

Different arrangements of springs and shaft configurations are currently employed for maintaining contact pressure as well as to hold the moving contact in open condition when repelled by electromagnetic forces called flip condition.

Arc chutes assemblies, made up of deion plates stacked up together are used for pulling, lengthening, splitting and quenching of electric arc during fault interruption.

Perforated metal sheet or mesh is used sometimes, so as to de-ionize and cool the hot ionized gases. In some breakers, perforated plastic sheet is used as an alternative.

Operating mechanism of the circuit breaker enables manually independent opening and closing of the contact system and does four operations: ON, OFF, Trip and Reset.

The trip unit senses the current flowing through the system, and under pre-specified abnormal conditions gives the command signal for the operating mechanism of the breaker to trip i.e., break the circuit. The trip unit used are generally either thermo-magnetic or electronic (microprocessor based) trip unit.

The various termination units/modules cater to the various types of termination like direct link, box clamp, spreader link, cable lug, rear, tunnel as per the customer requirements at the endpoint use.

The prior-art document US6377144discloses a molded case circuit breaker employing a trifurcated design that imparts structural stability and manufacturing efficiency. The design provides a separate top cover, mid cover and base wherein the mid-cover wall height to base wall ratio is such that the stresses imparted upon the base side walls when pressures are exerted, for example, by gaseous discharge are withstood. However this arrangement has the flexible covers which flex outwards at the time increased pressure inside and releases the pressure. Firstly Since covers flexes outside the breaker needs more space for mounting in comparison to present invention. Secondly the functionality of the breaker is difficult when multiple breakers are mounted side by side and can create flashover between two consequent breakers. Both of these drawbacks can be overcome by using present invention as its releases gasses in upward direction only.

The prior-art document US 7116194 discloses an electric pole for a low-voltage power circuit breaker, comprising an insulating enclosure that has a lower wall, an upper wall, two side walls, a rear wall and a front wall, at least one arc chute, at least one fixed contact and at least one moving contact that can be mutually coupled/uncoupled, and a first electric terminal and a second electric terminal that are functionally associated with the fixed contact and the moving contact and allow electrical connection of the pole in input and in output, its particularity consisting of the fact that the insulating enclosure comprises a first half-shell and a second half-shell which are mutually coupled along corresponding coupling surfaces and form a self-supporting structure, the first and second half-shells being shaped so as to form at least one compartment that is suitable to accommodate the fixed contact and the moving contact and the arc chute, and second and third containment volumes, which are arranged on mutually opposite sides with respect to the compartment and are suitable to accommodate respectively the first and second electric terminals. However said arrangement has a moving contact arrangement works with the help of extension spring. Also the arrangement doesn’t have any separate covering from bottom side which can cause failures in impulse with stands. On the other hand The arrangement used in present invention works on the principle of compression spring which is more reliable then said prior art also it has the additional covering from bottom side to provide better impulse withstand.

The prior-art document US 5298874 discloses a modular low voltage multi-pole circuit breaker, including a plurality of identical single-pole breaking units each including a parallelipipedic insulating box having two opposite parallel large side faces and two opposite parallel small side faces, two terminals located at respective opposite parallel small side faces, a stationary contact electrically connected to one of the terminals, a movable contact co-operable between a first position contacting the stationary contact and a second position separated from the stationary contact and a molded case for housing the single-pole breaking units. The molded case has two opposite parallel side walls having the same thickness, the single-pole breaking units being sequentially arranged and parallel to each other and parallel to the side walls such that adjacent single-pole breaking units are spaced apart a distance equal to twice the thickness of the side walls, the single-pole breaking units being spaced apart at a constant pitch. An operating mechanism is provided to be common to all single-pole breaking units for simultaneously operating all single-pole breaking units. However said prior art has a complete different arrangement which incorporates and pressure detector module with poles. In case of insufficient pressure build up the functioning of the breaker deteriorates. On the other hand the present invention incorporated a flip lock arrangement based on compression spring which provides much faster and reliable functionality.

The prior-art document US 6933814discloses a molded case, cassette type circuit breaker for a multi-pole electrical distribution circuit includes a number of cassettes equal to the number of poles in the multi-pole electrical distribution circuit and a pin disposed through each cassette. The pin is formed from a dielectric material. The pin may be further disposed through a portion of an operating mechanism for aligning the cassettes and the operating mechanism. Each cassette may include a rotor, a pair of electrical contacts, and a contact arm supported in the cassette by the rotor. In this embodiment, the pin may be a cross pin that extends between each rotor. The dielectric material may include phenolic, melamine, silicone, epoxy, polyester, fiberglass and the like. Alternatively, the pin includes a steel bar coated with the dielectric material, where the dielectric material may include, for example, epoxy, silicon, Teflon, and the like. A pair of end caps may be disposed over end surfaces of the rotor. Pole spacing between adjacent cassettes may be about one inch or less while providing sufficient dielectric integrity to meet requirements of the UL 489 standard. However said prior art has a double break arrangement with inbuilt trip unit arrangement. The double break arrangement has a higher number of components and higher assembly time which causes extra cost. Similarly the built in trip unit reduces the possibility of interchangeability of the trip unit. On the other hand the present invention has hardware free easy to assemble moving contact arrangement also provides the interchangeability of trip units.

In the view of above mentioned drawbacks and limitations there exists a need to propose a single break system with modularity of components and connections thereby simplifying assembly line/process, reducing the assembly cost and time at the same time, and providing the option for replacing the modules if required instead of complete breaker. The invention has a unique compression spring based flip lock arrangement which ensures better fault clearing and reduces the chances of contact reclosing. Also the unique design of single secondary arcing chamber achieved. This provides faster arc quenching and reduced stresses on main outer housing generated because of the arcing gas pressure.

SUMMARY

This summary is provided to introduce concepts related to a single break low voltage molded case circuit breaker. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.

In one implementation, a proposed invention is a robust modular and cassette arrangement based design of the single break system breaker.

In one implementation, a single break system with modularity of components and connections is proposed which enables to simplify assembly line/process, reduces the assembly cost and time at the same time, and provides various options for replacing the modules if required instead of complete breaker

In one implementation, the robust shaft construction provided in the proposed invention enables hardware free assembly and flips locking of moving contact with compassion spring on single break system.

In one implementation, the present invention relates to a circuit breaker, more particularly with the single break moulded case circuit breaker modularity in components and connections involved in the architecture of the breaker.

In one implementation, the present invention provides a compression spring based single break flip lock arrangement of moving concept. The unique design of moving contact housing/Shaft provides the hardware free and secondary operation free moving contact assembly which provides cost effective and better functionality.

In one implementation, the present invention provides the overall modularity of arrangement makes it easy to interchange and replace any module according to requirement.

In one implementation, the present invention provides a moving contact housing/shaft; compression spring based single break flip lock, modularity and variety of number of termination techniques without additional components.

Accordingly, in one implementation, an improved circuit breaker is disclosed. The improved circuit breaker comprises of a first assembly (15), a second assembly (18), a third assembly (22), a fourth assembly (32), a fifth assembly (44), a sixth assembly (47), and a seventh assembly (50). The said sixth assembly (47) is a complete breaker assembly combining said first assembly (15), said second assembly (18), said third assembly (22), said fourth assembly (32), and said fifth assembly (44). Further, said sixth assembly (47) is configured to provide a hardware free assembly and flips locking of at least one moving contact.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.

Figure 1 illustrates a complete assembly of various modules of the breaker in combined and sectional view, is shown, in accordance with an embodiment of the present subject matter.

Figure 2 illustrates an exploded view of complete breaker is shown, in accordance with an embodiment of the present subject matter.

Figure 3 illustrates across combined and sectional view of a pole module is shown, in accordance with an embodiment of the present subject matter.

Figure 4 illustrates an exploded view of a pole module is shown, in accordance with an embodiment of the present subject matter.

Figure 5 illustrates a pole module packing arrangement are shown, in accordance with an embodiment of the present subject matter.

Figure 6 illustrates a pole module with release mounting nut, is shown, in accordance with an embodiment of the present subject matter.

Figure 7illustrates an exploded view of mechanism assembly, is shown, in accordance with an embodiment of the present subject matter.

Figure 8illustrates a complete mechanism assembly, is shown, in accordance with an embodiment of the present subject matter.

Figure 9illustrates a pole module with isolator, is shown, in accordance with an embodiment of the present subject matter.

Figure 10 and Figure 11illustrates a pole module and mechanism assembly is shown, in accordance with an embodiment of the present subject matter.

Figure 12 illustrates a number of pole module assembly arrangement is shown, in accordance with an embodiment of the present subject matter.

Figure 13, Figure 14, Figure 15 and Figure 16 illustrates the pole module assembly with various components is shown, in accordance with an embodiment of the present subject matter.

Figure 17 and Figure18 illustrates the pole module assembly with bottom housing and chassis is shown, in accordance with an embodiment of the present subject matter.

Figure 19 and Figure20 illustrate chassis assembly with various components is shown, in accordance with an embodiment of the present subject matter.

Figure 21 and Figure22 illustrates a chassis and knob assembly of a breaker is shown, in accordance with an embodiment of the present subject matter.

Figure 23, Figure 24 and Figure25 illustrates the release module assembly with breaker is shown, in accordance with an embodiment of the present subject matter.

Figure 26, Figure 27, Figure 28 and Figure29 illustrates top cover assembly with IP covers and PTT components is shown, in accordance with an embodiment of the present subject matter.

Figure 30 illustrates an exploded view of top cover and outer cover assembly with breaker is shown, in accordance with an embodiment of the present subject matter.

Figure 31 and Figure 32 illustrates a complete breaker with termination arrangement is shown, in accordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION OF THE PRESENT INVENETION

Preferred embodiments of the present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.

The terms and words used in the following description 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.

It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

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.

In one implementation, the present invention is related to a robust modular and cassette arrangement based design of the single break system breaker.

In one implementation, an improved circuit breaker is disclosed. The improved circuit breaker comprises of a first assembly (15), a second assembly (18), a third assembly (22), a fourth assembly (32), a fifth assembly (44), a sixth assembly (47), and a seventh assembly (50). The said sixth assembly (47) is a complete breaker assembly combining said first assembly (15), said second assembly (18), said third assembly (22), said fourth assembly (32), and said fifth assembly (44). Further, said sixth assembly (47) is configured to provide a hardware free assembly and flips locking of at least one moving contact.

In one implementation, said improved breaker comprises of at least two outer enclosures (1, 2); a fixed terminal (3); an arc chute assembly (4); a shaft assembly (5); a nut (6); a rivet (7); a screw (8); a cassette assembly (9); a basic mechanism assembly (10); a lever (11); a mechanism module assembly (12); an isolator (13); at least two pins (14); at least two components (16); a pin (17); at least two other components (19); two set of screws (20, 21); a component (23); a housing (24); a chassis (25); a spring (26); a component (27); a chassis assembly (28); at least two screws (29); a knob (31); a release (33); at least two screws (34); a release module (35); a molded cover (36); IP covers (37, 38); a button (39); a spring (40); a component (41); a side component (42); a snap pin (43); a screw (45); a cover (46); a component (48); and a nut (49).

In one implementation, said first assembly (15) comprises of said cassette assembly (9) comprising said fixed terminal (3), said shaft assembly (5), and said arc chute assembly (4), wherein said shaft assembly (5) is assembled with at least two outer enclosures (1, 2) with the help of two projections and said at least two outer enclosures (1, 2) are packed using said rivet (7); and said isolator (13) is used with said cassette assembly (9) to ensure a proper isolation of said mechanism module assembly (12) from said cassette assembly (9), wherein mechanism module assembly (12) comprises said basic mechanism assembly (10), said lever (11), a plurality of links and springs.

In one implementation, said second assembly (18) is formed by assembling said first assembly (15) with two assemblies (9) on its two sides, wherein said pins (14) are aligned in a hole provided on said shaft assembly (5) of said assembly (9), said two components (16) are used in between said first assembly (15) and said two assemblies (9), said pin (17) is inserted in the hole provided on said shaft assembly (5) such that a length of pin (17) varies and is used to properly align all shaft assembly (5) together and ensures simultaneous movement of all shafts.

In one implementation, said a third assembly (22) is formed by placing said two other components (19) between side plates of said mechanism module assembly (12) and said two assembly (9), such that said two other components (19) has two through holes drilled on it in perpendicular planes the top holes are tapped which are used for tightening said screws (29) to hold said chassis assembly (28).

In one implementation, said fourth assembly (32) is a switch level assembly said improved circuit breaker which comprises said release (33); said at least two screws (34); and said release module (35).

In one implementation, said fifth assembly (44) is a top cover assembly and encloses said release module (35), and comprises said molded cover (36), said IP covers (37, 38), said button (39), said spring (40), said component (41), said side component (42), said snap pin (43), said screw (45), and said cover (46).

In one implementation, said seventh assembly (50) is inserted bellow the terminals and snap fits with the features provided on enclosure (1, 2) and comprises a component (48) and a nut (49).

In one implementation, the significant feature of the proposed invention it that a single break system with modularity of components and connections. Depending upon the type of electrical installation, circuit breakers used are either single pole or multi-pole having single break or multiple break arrangement. The modular pole construction in current invention having the single current breaking system allows assembling one or multiple poles together to form a single or multi-pole breaker. This standardization simplifies assembly line/process and reduces the assembly cost and time at the same time provides the option for replacing the modules if required instead of complete breaker.

The complete assembly of the breaker is shown in figure1. All the individual modules are enclosed in outer covers and not exposed to the customer/user thus provides an impressive aesthetic look. Various modules and enclosures used in assembly are shown in figure 2. The breaker can have multiple pole modules (9) (as shown in figure 9) also called cassette assembly to provide n-pole/ multiple (like 3-pole, 4-pole etc.) protection arrangement. Individual pole module has a fixed terminal (3) a moving shaft assembly (5) and an arrangement of Deion plates called arc chute assembly (4). An arc deflector of some molded material is inserted in arc chute assembly for better protection from arc. The shaft assembly has a shaft housing a moving contact attached with shaft housing with the help of some mean which allows the free movement of moving contact. A spring is used between two holders to provide required contact force. A flexible conductor (like braid, foil etc.) can be used to connect moving contact with terminal to ensure the movement of the moving contact. The orientation of the flexible conductor and terminal is arranged such a way that electromagnetic force generates on flexible conductor (as shown in figure3). This force aids to the opening of the moving contact and hold it in this condition thus improves the contact dynamics. The shaft assembly (5) is assembled with the outer enclosure (1) and (2) with the help of two projections provided on the shaft housing. A ferromagnetic material shield (7) is used to improve the repulsion between moving and fixed contacts. Fixed contact (3) also has an arc runner attached with it near fixed contact button to improve arc running. Nut (6) is placed between two enclosures at the time of packing which is used to attach release module with breaker using screw (8) as shown in figure6. Enclosure (1) and (2) are packed with the help of a rivet (7) as shown infigure5. This complete assembly (9) as shown in figure9 and figure 10 is a modular pole assembly with single break arrangement.

The pole assembly (9) with addition of some other components is used to make complete molded case breaker. An insulating component (13) as shown in figure 9 is used with the pole assembly (9) to ensure proper isolation of mechanism module assembly (12) from the live parts of assembly (9). The mechanism module (12) has a basic mechanism assembly (10) and a lever (11) (as shown in figure 7 and figure 8) which actuates limit switches. The limit switches are used to provide signals to auxiliary contacts and alarms etc. the basic mechanism assembly (10) consists of a number of links and springs to provide sufficient energy to rotate the shaft in on, off and trip conditions. The complete mechanism module (12) is mounted on the pole assembly (9) in the manner as shown in figure10. Two links coming out of module (12) are attached with the shaft assembly (5) using two pins (14) at the both sided of assembly (9) (as shown in figure11). This assembly of pole (9) and mechanism (12) with isolator (13) and two pins (14) is called y-pole assembly and indicated as assembly (15) also can be called Y-pole of breaker.

For making 3-Pole breaker the assembly (15) (as shown in figure 12) is assembled with two assemblies (9) both side which forms R and B-poles. At the time of assembly pins (14) at the both sides of assembly (15) are aligned in the hole provided on the shaft housing (5) of assembly (9). The two components (16) are used in-between all three pole modules to ensure the sufficient clearance between R, Y, B poles as well as better tightening of pole modules together. Similarly n- number of pole modules can be added together to make an n-Pole breaker.

A pin (17) is inserted in the hole provided on the shaft hosing. Length of pin (17) varies number of pole modules added. The pin (17) is used to properly align all shaft assemblies together and ensures simultaneous movement of all shafts. All three pole modules assembled with pin (17) is indicated as assembly (18). Two other components (19) are placed between side plates of mechanism (12) and R and B poles (9) as shown in figure 14. The component (19) has two through holes drilled on it in perpendicular planes the top holes are tapped which are used for tightening the screws (29) (as shown in figure21) to hold chassis assembly (28). Two set of screws (20) and (21) of some length variation with nuts and washers are used to tighten the all three pole modules or assembly (18) firmly (as shown in figure 15).

The components (19) are placed such a way that screw (21) passes through its non-threaded holes and hold it on the place. Length of the screws (20) and (21) varies according to the n-number of pole requirement. The screws (21) also pass through the holes provided on the mechanism (12) side plates and fix it on the position. Screws (20) hold the all three pole modules (9) together also provide the support to enclosure (1) and (2) to be on position of individual pole module (9). The assembly as shown in figure15 is indicated as assembly (22) which is basic n-pole breaker assembly. Component (23) is attached with the assembly (22) which engages with a projection provided on the shaft housing of the shaft assembly (5) (as shown in figure16). Component (23) is free to slide in a groove provided on the enclosure (2) with the rotation of shaft. This component actuates the limit swathes according to the true position of shaft (whether on or off).

The assembly (22) with component (23) is placed inside a lower enclosure called bottom housing (24) (as shown in figure 17). The housing (24) has snap lock arrangement in which four rectangular slots given on side wall of (24) engages with the projection provided on the enclosure (1) and (2). Housing (24) protect the assembly (22) from bottom side and prevent the component (23) to come out (as shown in figure 17) also provides the better aesthetics for breaker. Assembly (28) is mounted from the top side of assembly (22) (as shown in figure 18). Assembly (28) is having a molded component (25) called chassis which performs as a platform to mount all the accessories like UV release, Shunt release, Flux tripping device and limit switches for signaling alarms etc. the component (27) assembles with (25) with the help of spring (26) (as shown in figure 19 and 20). Component (27) actuates by the link coming out of mechanism module (12) and functions to reset the UV/shunt release. Spring (26) used to bring back the component (27) on its initial position. Assembly (28) fixed with breaker assembly (22) with the help of two screws (29) which engage with component (19) (as shown in figure 21).

Also at the opposite side of screws (29) components (25) has snap fit arrangement which engages with the grove given on enclosure (1) and (2) and fixes itself firmly. A knob (31) made of molded material is inserted on the operating link coming out of mechanism module (12) (as shown in figure22). The operator can switch breaker on, off or can reset by rotating the knob up and down.

An assembly as shown in figure22 is indicated as the assembly (32) which is the switch level assembly of breaker i.e. it doesn’t have any sensing unit or release. Release modules (33) which can either be a thermal-magnetic, electronic or having any type of sensing unit can easily be attached or removed with breaker (32) as per requirement (as shown in figure23). The release module can be mounted on the breaker with the help of two screws (34) (as shown in figure24) which passes through the holes provided on the chassis (25) and holes provided on the release module assembly (33) then engages with two nuts inserted in the pockets provided on bottom housing (24) (as shown in figure21). This arrangement ensures the proper mechanical attachment of the release module with the breaker and reduces the mechanical stresses on electrical joints and parts. To establish electrical contact between release (33) and breaker assembly (32) nuts (8) tightened (as shown in figure25) which have been already attached in pole module assembly (9) (as shown in6). Screws (8) join the terminal attached with the shaft assembly (5) to the release module terminals to establish electrical contact. Release module (33) has a trip lever which hits the trip link of mechanism assembly (12) and trips the breaker when fault sensed or trip command issued.

To improve the ingress protection of this breaker assembly with release module 35 is enclosed with a top cover assembly (44) (as shown in figure29). Top cover assembly (44) has a molded cover 36 and two other molded small covers (37) and (38) (as shown in figure26) also called IP covers. IP covers (37) and (38) insert in the feature provided on the cover (36) and lock there. Covers (37) and (38) provide IP protection to the breaker assembly (35) in all positions of knob which may either be on, off, trip or any intermediate position and ensures the safety of operator. At the same time covers (37) and (38) also ensures the free movement of the knob thus minimizes operating forces. Top cover assembly (44) also have push to trip (PTT) arrangement which allows operator to trip the breaker manually by pressing the button (39) when required. The button (39) with spring (40) (as shown in figure 27) enters in a slot provided on the top cover (36) from the front side of (36). From the other side component (42) comes in the same slot and snap fits with component (39) (as shown in figure 28). Component (42) also restricts the button (39) to come out because of spring force. Spring (40) is used to bring back the whole arrangement to its initial position when it pressed. Component (41) is a metallic part which hinges with a snap pin (43) on top cover (36). Component (41) is inserted in projection given on component (42) and hits the trip link of mechanism module (12) when button (39) pressed from front side. The button (39) rests in very small opening on cover 36 thus ensures only tool operation on it.

The top cover (36) of assembly (44) has snap arrangement which attaches with the slots provided in component (25) of chassis assembly (28) and fixes it on the position (as shown in figure30). A screw (45) is also used to tighten assembly (44) with breaker (35) and ensures proper fixing and no accidental opening of top cover assembly (44). An outer cover (46) is also attached on the top cover assembly (44) with the snap fits. This cover (46) ensures the IP protection by covering all slots and opening on the top cover (36) and improves the aesthetics also. The assembly (47) (as shown in figure 31) is the complete breaker assembly with all modules assembled together.

With the breaker assembly (47) a variety of termination option can be used and interchangeability between various standard termination methods can be achieved. Assembly (50) (as shown in figure 32) is inserted below the terminals and snap fits with the features provided on enclosure (1) and (2). Assembly (50) has one molded component a (48) and a nut (49). Component (48) holds the nut (49) on its position and prevents its rotation while tightening. For spreader, link or cable lug type of termination standard screws can be used. Screws engage with nut (49) and can be tightened from the hole provided on the chassis (25). For direct cable connection a box clamp or tunnel clamp can be used for that only component will be used and nut will be taken out. For rear termination the bottom of component (48) can be knocked off to insert the terminals and screws can be tightened from top side.

In one implementation, the proposed invention is a robust modular and cassette arrangement based design of the single break system breaker. The robust shaft construction provides hardware free assembly and flips locking of moving contact with compression spring on single break system. The repulsion loop formed in flexible conductor with the help of terminal and flexible conductor orientation which improves contact dynamics and positive locking. The hardware free and true indication assembly of auxiliary and trip alarm actuators. The unique mechanism and contact system design to achieve Positive-Isolation and Trip-Free conditions. The proposed invention is easy to accessible and less time consuming accessories mounting. The IP Covers are completely attached with top cover. The various standard termination methods can be used without addition of any new component. The rigid structure of arc deflectors prevent collapsing of arc chute assembly in case of heavy thermal and mechanical stress associated with short circuits. Also, ablative nature of the material used, ensures low let through energy value. The improved thermal and electrical performance due to contact erosion compensation is given. This also gives an option to use button of less thickness for material and cost saving. The integral venting channel in the chassis which reduces the number of components and ensure ease of assembly is provided.

Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features:

One feature for the invention is that, the proposed invention discloses a modular Cassette based design for single break system breaker

Another feature of the invention is that, a hardware free shaft assembly with flip lock feature using compression spring.
Another feature of the invention is that, a repulsion loop formation in flexible conductor improves contact dynamics is disclosed.

Another feature of the invention is that, hardware free and true indication of shaft location and mechanism trip condition is disclosed.

Another feature of the invention is that, a unique mechanism and contact system is designed to achieve Positive-Isolation and Trip-Free conditions.

Another feature of the invention is that, an easy to accessible and less time consuming accessories mounting is disclosed.

Yet another feature of the invention is that, the completely integrated top and IP covers are disclosed.

Yet another feature of the invention is that, the termination method for variety without addition of components is possible.

Still another feature of the invention is that, an improved thermal and electrical performance due to contact erosion compensation is enabled.

Still another feature of the invention is that, an integral venting channel in the chassis is provided in the proposed invention.

Although a single break low voltage molded case circuit breaker has been described in language specific to structural features and/or methods, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific features or methods or devices described. Rather, the specific features are disclosed as examples of a single break low voltage molded case circuit breaker.
,CLAIMS:1. An improved circuit breaker, comprising:
an first assembly (15);
a second assembly (18);
a third assembly (22);
a fourth assembly (32);
a fifth assembly (44);
a sixth assembly (47); and
a seventh assembly (50), wherein
said sixth assembly (47) is a complete breaker assembly combining said first assembly (15), said second assembly (18), said third assembly (22), said fourth assembly (32), and said fifth assembly (44);
said sixth assembly (47) is configured to provide a hardware free assembly and flip locking of at least one moving contact.

2. An improved circuit breaker as claimed in claim 1 comprises:
at least two outer enclosures(1, 2); a fixed terminal (3); an arc chute assembly (4); a shaft assembly (5); a nut (6); a rivet (7); a screw (8); a cassette assembly (9); a basic mechanism assembly (10); a lever (11); a mechanism module assembly (12); an isolator (13); at least two pins (14); at least two components (16); a pin (17); at least two other components (19); two set of screws (20, 21); a component (23); a housing (24); a chassis(25); a spring (26); a component (27); a chassis assembly (28); at least two screws (29); a knob (31); a release (33); at least two screws (34); a release module (35); a molded cover (36); IP covers (37, 38); a button(39); a spring (40); a component (41); a side component (42); a snap pin (43); a screw (45); a cover (46); a component (48); and a nut (49).

3. The improved circuit breaker as claimed in claims 1 and 2, wherein said first assembly (15) comprises:
said cassette assembly (9) comprising said fixed terminal (3), said shaft assembly (5), and said arc chute assembly (4), wherein said shaft assembly (5) is assembled with at least two outer enclosures(1, 2) with the help of two projections and said at least two outer enclosures(1, 2) are packed using said rivet (7); and
said isolator (13) is used with said cassette assembly (9) to ensure a proper isolation of said mechanism module assembly (12) from said cassette assembly (9), wherein mechanism module assembly (12) comprises said basic mechanism assembly (10), said lever (11), a plurality of links and springs.

4. The improved circuit breaker as claimed in claims 1 to 3, wherein said second assembly (18) is formed by assembling said first assembly (15) with two assemblies (9)on its two sides,
wherein said pins (14) are aligned in a hole provided on said shaft assembly (5) of said assembly (9), said two components (16) are used in between said first assembly (15) and said two assemblies (9), said pin (17) is inserted in the hole provided on said shaft assembly (5) such that a length of pin (17) varies and is used to properly align all shaft assembly (5) together and ensures simultaneous movement of all shafts.

5. The improved circuit breaker as claimed in claims 1 to 4, wherein said a third assembly (22) is formed by placing said two other components (19) between side plates of said mechanism module assembly (12) and said two assembly (9), such that said two other components (19) has two through holes drilled on it in perpendicular planes the top holes are tapped which are used for tightening said screws (29) to hold said chassis assembly (28).

6. The improved circuit breaker as claimed in claims 1 to 5, wherein said fourth assembly (32) is a switch level assembly said improved circuit breaker which comprises said release (33); said at least two screws (34); and said release module (35).

7. The improved circuit breaker as claimed in claims 1 to 6, wherein said fifth assembly (44) is a top cover assembly and encloses said release module (35), and comprises said molded cover (36), said IP covers (37, 38), said button (39), said spring (40), said component (41), said side component (42), said snap pin (43), said screw (45), and said cover (46).

8. The improved circuit breaker as claimed in claims 1 to 7, wherein said seventh assembly (50) is inserted below the terminals and snap fits with the features provided on enclosure (1, 2) and comprises a component (48) and a nut (49).