CLIAMS:1. A compact high performance circuit breaker arrangement (5) comprising:
- an operating mechanism (1) to operate the circuit breaker (5) in ON, OFF and TRIP conditions;
- at least one short circuit release assembly (2) to trip the circuit breaker (5) in case of short circuit fault condition;
- at least one arc chamber (3) to quench arc caused by short circuit fault condition; and
- at least one thermal release assembly (4) to trip the circuit breaker (5) in case of overload current;
wherein said short circuit release assembly (2) is located at an angle with respect to horizontal direction of said operating mechanism (1) providing space at the top for said operating mechanism (1) and space at the bottom for said arc chamber (3).

2. The arrangement as claimed in claim 1, wherein said operating mechanism (1) comprises of :
- at least one moving contact (6) to operate the circuit breaker (5);
- at least one contact support(7) to hold said moving contact (6); and
- at least one tripping latch (8)to trip the circuit breaker (5) in case of fault condition.

3. The arrangement as claimed in claim 1, wherein said short circuit release assembly (2) comprises of:
- at least one operating coil (9);
- at least one plunger (10) to provide hammer action;
- at least one fixed contact (11) to complete the circuit breaker (5) with moving contact (6); and
- at least one terminal (12) for termination of circuit.

4. The arrangement as claimed in claim 1, wherein said arc chamber (3) comprises of:
- plurality of de-ion plates (13);
- at least one arc runner (14); and
- at least one mounting support (15).

5. The arrangement as claimed in claim 4, wherein said de-ion plates (13) are in slanted manner i.e. divergent in the said arc chamber (3).

6. The arrangement as claimed in claim 1, wherein said variable thermal release assembly (4) comprises of:
- at least one trip plate (16);and
- at least one control knob (17);
- at least one calibration mechanism (18)
wherein said control knob (17) is accessible to user to control overload characteristic and calibration mechanism (18) of trip plate (16) for factory setting.

7. The arrangement as claimed in claim 1, wherein said short circuit release (2) is placed closer to said terminal (12).

8. The arrangement as claimed in claim 1, wherein said short circuit release (2), said moving contact (6) of the said operating mechanism (1) is placed in a manner that during short circuit fault condition said plunger (10) of said short circuit release (2) push tripping latch (8) of said operating mechanism (1) to hit moving contact assembly causing fast/forceful opening of said moving contact (6).

9. The arrangement as claimed claim 5, wherein said divergent de-ion plates (13) along with said arc runner (14) is mounted on mounting support (15) and are placed beside said short circuit release (2).

10. The arrangement as claimed in claim 1, wherein said operating mechanism (1) is placed at upper left half of the circuit breaker (5) with moving contact (6) closer to plunger (10) of short circuit release (2) in ON condition.

11. The arrangement as claimed in claim 1 to 10, wherein said trip plate(16) of the said thermal assembly (4) is sensitive to overload current and operates tripping latch(8) of said operating mechanism (1) and turn the circuit breaker (5) to OFF condition based on the preset threshold value.

12. The arrangement as claimed in claim 6, wherein said threshold value is controlled through said control knob (17) of the said thermal assembly (4) accessible to end user.

13. The arrangement as claimed in claim 6, wherein said control knob (17) is directly connected to said trip plate (16).

14. The arrangement as claimed in claim 1, wherein said thermal assembly (4) is placed in upper portion of the circuit breaker (5)at right side of 45 mm cutout area (20).

15. The arrangement as claimed in claim 1, further comprises contact indication lever for true contact indication visible to end user by window (24).

16. The arrangement as claimed in claim 1, further comprises fault indication lever for short circuit fault indication visible to end user by window (23).

17. The arrangement as claimed in claim 1, wherein said operating mechanism (1) is placed in a 45 mm cutout area (20) of the circuit breaker (5).

18. The arrangement as claimed in claim 1, wherein said circuit breaker (5) is housed in a housing (19) and optionally mounted on din rail or in double door distribution board based on requirement of user.
,TagSPECI:FIELD OF THE INVENTION

The present invention relates to compact circuit breaker architecture to achieve high breaking capacity and accessibility of variable thermal release to end user. More particularly the invention relates to compact circuit breaker with 45mm cutout to provide protection against overload current, thermal protection and short circuit current which can be mounted on din rail as well as in double door distribution board.

BACKGROUND OF THE INVENTION

Compact circuit breakers are used to give protection against overload current (thermal protection) and short circuit current. With increase in demand of short circuit breaking capacity and requirement of flexibility to allow overload current through breaker. It was a challenge to design breaker which will give high short circuit breaking capacity and provision for easy access for end user to control overload protection capacity in compact size.

To achieve high breaking capacity in compact breaker it is important to have efficient arc chamber as well as to forcefully break open moving contact by plunger of short circuit release termed as hammer action. Also to give access to end user for variable thermal release knob, it is important to have thermal assembly in 45 mm cutout of Compact breaker.

US 4229630A discloses a circuit breaker comprising first and second spaced-apart stationary contacts, a plurality of movable contacts and an arcing contact which are capable of operating between open and closed positions. An arc chamber is disposed adjacent one of the stationary contacts, the arcing contact, and the movable contacts, and comprises a frame with back and two parallel sides. A plurality of deionization plates are supported by frame and each deionization plate has an opening therein distant from the back of the frame. The deionization plate openings are aligned with each other, and the arcing contact is disposed within the aligned openings. A generally U-shaped arc runner is secured to one of the end deionization plates and one of the stationary contacts. An insulating member is disposed between the arc runner and the stationary contact so that the arc runner is electrically insulated from the stationary contact except where it is secured thereto. Also included is an operating mechanism for effecting movement of the movable and arcing contacts between the open and closed positions.

US 5153545 A discloses a refractory fiber insert within the cover of a molded case circuit breaker interfaces between the interior of the circuit breaker cover and the top surface of the circuit breaker arc chute to prevent the arc by-products generated within the arc chamber from re-entering the arc chamber. A shaped slot formed within the fiber insert automatically compensates for manufacturing tolerances to precisely locate the insert between the cover interior and the top surface of the arc chute.

In conventional method, mechanism is placed in a 45mm cutout of breaker with moving contact rotating along vertical axis; and short circuit release placed either in horizontal direction or vertical direction.

In case of short circuit release placed horizontally; it is possible to give hammer action, but de-ion plates of arc chamber assembly can only be placed linearly. And it is proven that placement of divergent de-ion plate in arc chamber gives better short circuit breaking capacity than linear placement. Also it is very difficult to place thermal release assembly in 45mm cutout.

In case of short circuit release placed vertically, it is possible to place thermal release in 45mm cutout; but direct hammer action is not possible in this type of construction. Also placing divergent de-ion plates in arc chamber becomes very difficult.

Hence innovative way of structuring above 4 assemblies in compact breaker becomes very important. The present invention describes a novel approach to design an architecture which will meet both the above requirement by accommodating most efficient arc chamber for high breaking capacity and mechanism of variable thermal protection.

OBJECT OF THE INVENTION

The prime object of the present invention is to overcome one or more of the drawbacks of the related prior art.

It is an object of the present invention to provide an operating mechanism of short circuit release at an optimized angle.

It is a further object of the present invention to provide flexible and efficient arc chamber.

Yet another object of the present invention is to enhance the short circuit breaking capacity of a compact circuit breaker.

It is an object of the present invention to provide a compact circuit breaker architecture having an improved operating mechanism placed in a 45mm cutout of compact circuit breaker.

It is a further object of the present invention is to provide access to end user to control overload capacity of highly efficient thermal release.

Yet another object of the present invention is to provide contact indication mechanism for true contact indication.

It is an object of the present invention is to provide fault indication mechanism giving positive indication for short circuit fault.

These and other objects of the present invention will become readily apparent from the following detailed description read in conjunction with the accompanying drawings.

SUMMARY OF INVENTION

The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention.

In a non-limiting aspect of the present invention there is provided a compact circuit breaker arrangement to give protection against overload current, thermal protection and short circuit current comprising:
- an operating mechanism to operate the circuit breaker in ON, OFF and TRIP conditions;
- at least one short circuit release assembly to trip the circuit breaker in case of short circuit fault condition;
- at least one arc chamber to quench arc caused by short circuit fault condition; and
- at least one thermal release assembly to trip the circuit breaker in case of overload current;
wherein said short circuit release assembly is located at an angle with respect to horizontal direction of said operating mechanism providing space at the top for said operating mechanism and space at the bottom for said arc chamber.

In a preferred embodiment of the present invention short circuit release, moving contact of the operating mechanism is placed in a manner that during short circuit fault condition plunger of short circuit release push tripping latch of said operating mechanism to hit moving contact assembly causing fast/forceful opening of said moving contact.

To enable the invention to be more clearly understood and carried into practice, reference is now made to the accompanying drawing in which like references denote like parts throughout the description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The different preferred embodiments of the invention will now be described, by way of example with reference to the accompanying drawings, in which:

Figure 1 illustrates front view of Compact circuit breaker of the present invention in ON condition.

Figure 2depicts top view of Compact circuit breaker of the present invention illustrating accessibility to control knob.

Figure 3 shows part of short circuit release and operating mechanism of the present invention showing hammer action.

Figure 4 illustrates preferred complete architecture of Compact circuit breaker of the present invention in OFF state.

Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.
Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION OF THE INVENTION

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. In addition, descriptions of well-known functions, symbols, abbreviation and constructions are omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

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

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 is intended to provide.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

The advantages, nature, and various additional features of the invention will appear more fully upon consideration of the illustrative experiment now to be described in detail in connection with accompanying drawings.

In accordance with the preferred embodiment of the invention, the compact circuit breaker construction has four important assemblies, first, operating mechanism, second, short circuit release, third, arc chamber, and fourth, thermal release.

According to a non-limiting embodiment of the present invention, Figure 1 and Figure 3 depicts a compact circuit breaker (5) is having an operating mechanism (1) used to operate moving contact (6) to make breaker ON and OFF, it also consist of contact support (7) which hold moving contact (6), and a tripping latch (8) to trip the circuit breaker (5) in case of fault condition. Short circuit release(2) used to trip the circuit breaker (5) in case of short circuit fault, it consist of operating coil (9), plunger (10) to give hammer action, fixed contact (11) to complete circuit with moving contact and terminal (12) for termination. Arc chamber (3) which is used to quench arc caused by short circuit consist of de-ion plates (13), arc runner (14), mounting support (15).

Thermal release (4) is used to trip the circuit breaker (5) in case of overload current consist of trip plate (16), control knob (17)for user to control overload characteristics and calibration mechanism (18) as shown in Figure 2 and Figure 4. These all components are housed in housing (19).

The uniqueness of the present invention lies in the direction of placement of short circuit release (2), and moving contact (6) of operating mechanism (1). Short circuit release (2) is placed at an angle with respect to horizontal. It is optimized so that enough space will be available at the top for mechanism (1) and space for divergent de-ion plates (13) at the bottom. With respect to short circuit release (2), moving contact (6) of mechanism (1) is placed in such a way that, during short circuit fault; plunger (10) of the short circuit release (2) push tripping latch (8) which hits to moving contact assembly (6,7). This causes fast/forceful opening of moving contact (6), which is very important for high short circuit breaking capacity. Also the construction of the present invention allows to place de-ion plates in slanted manner i.e. divergent de-ion plates (13) in arc chamber (3), which gives higher blow out force during short circuit and hence fault clearing becomes fast. In addition to this, more number of de-ion plates (13) than conventional method can be placed in arc chamber, which causes fast quenching of arc and hence clearing short circuit fault condition.

Variable thermal assembly (4) is placed at right side of 45 mm cutout area (20). Trip plate (16) is sensitive to overload current, when overload current is above threshold value, it operates tripping latch (8) of mechanism (1) and turn the circuit breaker (5) to off. This threshold value is controlled through control knob (17), which is accessible to end user. Advantage of keeping thermal assembly (4) in upper portion of the circuit breaker is that, control knob (17) can be directly connected to trip plate (16), giving higher efficiency for thermal release (2).

Architecture Description and Working of Breaker:

Compact circuit breaker (5) is Modular device which can be mounted on din rail as well as in Double door distribution board because of its 45mm cutout.

In one implementation, variable thermal assembly (4) is placed at right side of 45 mm cutout area (20). Trip plate (16) is sensitive to overload current, when overload current is above threshold value, it operates tripping latch (8) of mechanism (1) and turn the circuit breaker (5) to off. This threshold value is controlled through control knob (17), which is accessible to end user.

Figure 1 and Figure 4 shows complete architecture of compact circuit breaker (5) according to the preferred embodiment of the present invention. As shown in the figures, short circuit release (2) is placed at an angle with respect to horizontal and closer to terminal (12). The operating mechanism (1) is placed at upper left half of the circuit breaker (5) with moving contact (6) closer to plunger (10) of short circuit release (2) in ON condition. Divergent de-ion plates (13) along with arc runner (14) is mounted on mounting support (15) and are placed beside short circuit release (2).

True contact indication is shown by contact indication lever (Figure 3) and is visible to end user by window (24) as shown in Figure 2. Short circuit fault indication is shown by fault indication lever (Figure 3) and is visible to end user by window (23) as shown in Figure 3.

Thermal release is placed at upper right side of the circuit breaker (5). Control knob (17) is attached with trip plate (16), which is accessible to end user as shown in Figure 2. User can rotate said knob (17) and adjust threshold of overload current. Calibration mechanism (18) is placed at bottom of trip plate (16) for factory setting.

Although the invention has been described with reference to particular examples of the invention, it should be appreciated that it may be exemplified in other forms. The invention qualifies to be adopted in a variety of other embodiments such modifications and alternatives obtaining the advantages and the benefits of the present invention will be apparent to those skilled in the art. All such modifications and alternatives will be obvious to a person skilled in art. Further the present invention has been described with respect to certain specific embodiments, it will be clear to those skilled in the art that the inventive features of the present invention are applicable to other embodiments as well, all of which are intended to fall within the scope of the present invention.

The description herein contains many specifics; these should not be construed as limiting the scope of the invention, but as merely providing illustrations of some of the embodiments of the invention. One of ordinary skill in the art will appreciate that elements and materials other than those specifically exemplified can be employed in the practice of the invention without resort to undue experimentation. All art-known functional equivalents, of any such elements and materials are intended to be included in this invention. Numerous variations, changes and substitutions may be made without departing from the invention herein.