CLIAMS:1. A circuit breaker for providing spring discharge mechanism during loading and/or unloading and/or maintenance of said circuit breaker, comprising:
a contact assembly having contact structures movable between a closed and an open position;
at least one compressing spring operable between a charged and a discharged position, said compressing spring operatively coupled to said contact structures;
an open latch and a close latch operatively coupled to said contact structures and said compressing spring, respectively;
wherein said compressing spring is configured to store energy based on latching achieved by said open latch and said close latch;
said circuit breaker CHARACTERIZED IN THAT it includes:
a self-actuating spring discharge mechanism comprising:
a closing actuator link (10) rigidly fixed on said close latch (11) and actuated by means of a slider link (6);
said slider link (6) rigidly guided on at least one side plate (3);
a coupler link (8) between said slider link (6) and at least one actuator link (9) configured to get actuated from at least one actuator hump (2) fixed on a racking cover (1); and
a spring (5) configured to reset the mechanism to its initial position;
wherein, during loading to unloading and/or maintenance of said circuit breaker,
said hump (2) is configured to provide input in the form of initial force or movement to said actuator link (9) and
thereby close said actuator link (10) through said coupler link (8) and said slider link (6), so as to enable rotation of said close latch (11) to collapse closing circuit and discharge said compressing spring.

2. The circuit breaker as claimed in claim 1 is operable in “Disconnected” or “Isolated” or “OFF”, “Test” or “Maintenance”, and “Connected” or “ON” condition.

3. The circuit breaker as claimed in claims 1 and 2, wherein said-actuating spring discharge mechanism is operable during loading and unloading of said circuit breaker from “Isolated” to ‘Maintenance’ position.

4. The circuit breaker as claimed in claims 1 and 2, wherein said-actuating spring discharge mechanism is operable during loading and unloading of said circuit breaker from “Maintenance” to “Isolated” position.
,TagSPECI:TECHNICAL FIELD OF THE INVENTION

[001] The present subject matter described herein, in general, relates to protection devices, particularly circuit breakers, and in particular, to a spring discharge mechanism in circuit breakers to achieve safety of maintenance personnel.

BACKGROUND OF THE INVENTION

[002] Traditionally known, circuit breaker operating mechanism permits circuit breaker to store the energy by compressing springs that are linked to a contact assembly of the circuit breaker by latching different links. Stored energy of springs and latching between the linkages allows breaker to make the contacts, hence completing the electrical circuit (closing of breaker) and also break the contacts, thereby interrupting the electrical circuit (tripping of breaker). Switchgear mechanisms use methods of latching for storing the spring energy and achieving its intended motion.

[003] In a draw out type of circuit breaker, the circuit breaker is supported on a rail assembly, which is an integral part of a cradle assembly. The cradle assembly consists of the base plate, racking assembly, side plates for guiding breaker and rail assembly. Racking operation is accomplished by the racking mechanism mounted on the base plate.

[004] Further, in the draw out type of circuit breaker, positions of the circuit breaker with respect to the cradle are normally defined as 'Disconnected', 'Test' and 'Connected'. When the circuit breaker is completely racked in i.e., in 'Connected' position, the circuit breaker terminals are in contact with cradle terminals through cradle jaws. In this condition, both a power (main) circuit and a control circuit are connected, and the circuit breaker can be switched ON. When the breaker is completely racked out i.e., in 'Disconnected' position, both the main circuit and the control circuit are disconnected. In the 'Test’ position, the power (main) circuit is not connected but the control circuit is connected. The breaker can also be drawn out to ‘Maintenance’ position where it can be lifted off the cradle for servicing and maintenance activities.
[005] However, in the prior-art the switchgear manufacturers provide a spring discharge mechanism during unloading the breaker from ‘Isolated’ to ‘Maintenance’ position and not in loading the breaker into the cradle assembly. During discharge mechanism, the dependency of main spring discharge mechanism from main linkages is required. This creates a major problem of spring remaining in charged condition while ‘Maintenance’ / maintenance.

[006] In view of the above, there is a need of a current sensor that can overcome the drawbacks of the existing spring discharge mechanism known in the prior art.

SUMMARY OF THE INVENTION

[007] The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.

[008] An object of the present invention is to provide a spring discharge mechanism which is configured to operate in both directions i.e., loading and unloading of the circuit breaker from ‘Isolated’ to ‘Maintenance’ position and vice versa.

[009] Another object of the present invention is to provide a self powered compact current sensor with vertical mounting and multiple turns to have amplified current / power at lower current, turn’s connection to each other simplified with optimized number of links and number of joints to have ease of assembly.

[0010] Accordingly, in one implementation, a circuit breaker for providing spring discharge mechanism during loading and/or unloading and/or maintenance of said circuit breaker is disclosed. The circuit breaker comprises a contact assembly having contact structures movable between a closed and an open position; at least one compressing spring operable between a charged and a discharged position, said compressing spring operatively coupled to said contact structures; an open latch and a close latch operatively coupled to said contact structures and said compressing spring, respectively; wherein said compressing spring is configured to store energy based on latching achieved by said open latch and said close latch. The circuit breaker achieves advancement to operate in both directions i.e., loading and unloading of the circuit breaker from ‘Isolated’ to ‘Maintenance’ position and vice versa as it includes a self-actuating spring discharge mechanism comprising: a closing actuator link (10) rigidly fixed on said close latch (11) and actuated by means of a slider link (6); said slider link (6) rigidly guided on at least one side plate (3); a coupler link (8) between said slider link (6) and at least one actuator link (9) configured to get actuated from at least one actuator hump (2) fixed on a racking cover (1); spring (5) used for resetting the mechanism to its initial position wherein, during loading to unloading and/or maintenance of said circuit breaker, said hump (2) is configured to provide input (said input is referred as initial force or movement which is given by the said hump) to said actuator link (9) and thereby close said actuator link (10) through said coupler link (8) and said slider link (6), so as to enable rotation of said close latch (11) to collapse closing circuit and discharge said compressing spring.

[0011] Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:

[0012] Figure 1 illustrates an actuated position of spring discharge mechanism, in accordance with the subject matter of the present invention.

[0013] Figure 2 illustrates a schematic of mechanism-1, in accordance with the subject matter of the present invention.

[0014] Figure 3 illustrates a schematic of mechanism-2, in accordance with the subject matter of the present invention.

[0015] 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 PRESENT INVENTION

[0016] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary.

[0017] Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

[0018] 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.

[0019] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] A person skilled in the art will appreciate that for understanding purpose the present invention is explained with the help of circuit breakers however the disclosed subject matter shall not be considered as the limiting factor for the scope of present invention.

[0024] Below mentioned is the list of components used throughout the invention along with their respective reference numerals. However the list of components shall not be considered as the limiting factor for the scope of present invention.
1. Racking cover
2. Actuator hump
3. Side plate
4. Rivet
5. Spring
6. Slider link
7. Guiding screw
8. Coupler link
9. Actuator link
10. Closing actuator link
11. Closing shaft
12. Main spring
13. Tripping actuator link

[0025] In one implementation, the present invention provides a spring discharge mechanism configured to operate in both directions: loading and unloading of the breaker from ‘Isolated’ to ‘Maintenance’ position and vice versa.

[0026] In one implementation, a circuit breaker for providing spring discharge mechanism during loading and/or unloading and/or maintenance of said circuit breaker is disclosed. The circuit breaker comprises a contact assembly having contact structures movable between a closed and an open position; at least one compressing spring operable between a charged and a discharged position, said compressing spring operatively coupled to said contact structures; an open latch and a close latch operatively coupled to said contact structures and said compressing spring, respectively; wherein said compressing spring is configured to store energy based on latching achieved by said open latch and said close latch. The circuit breaker achieves advancement to operate in both directions i.e., loading and unloading of the circuit breaker from ‘Isolated’ to ‘Maintenance’ position and vice versa as it includes a self-actuating spring discharge mechanism comprising: a closing actuator link (10) rigidly fixed on said close latch (11) and actuated by means of a slider link (6); said slider link (6) rigidly guided on at least one side plate (3); a coupler link (8) between said slider link (6) and at least one actuator link (9) configured to get actuated from at least one actuator hump (2) fixed on a racking cover (1); spring (5) is used for resetting the mechanism to its initial position wherein, during loading to unloading and/or maintenance of said circuit breaker, said hump (2) is configured to provide input to said actuator link (9) and thereby close said actuator link (10) through said coupler link (8) and said slider link (6), so as to enable rotation of said close latch (11) to collapse closing circuit and discharge said compressing spring.
[0027] In one implementation, the spring discharge mechanism takes input from cradle of breaker so it is ensure positive working of mechanism, and the mechanism is directly coupled with closing circuit main shaft.

[0028] In one implementation, the present invention comprises a closing actuator link (10) which is rigidly fixed on closing shaft (11) and actuated by slider link (6), slider link (6) which rigidly guided on side plate (3),coupler link (8) it is intermediate link between slider link (6) and actuator link (9) which get actuated from actuator hump (2) fixed on racking cover (1) spring (5) used for resetting the mechanism to its initial position. The actuator hump is an integrated part of racking cover.

[0029] In one implementation, figure 1 shows actuation point of the spring discharge mechanism. When breaker getting pulled outward towards maintenance position actuator hump (2)first actuated tripping actuator link (13) and then closing actuator link (10) get actuated so that breaker remains off condition.

[0030] In one implementation, when closing actuator link (10) is actuated it moves coupler link (8) clockwise as coupler link (8) is rigidly coupled with slider link (6) it move downwards as shown in figure 2. When slider link (6) moves downwards it rotates closing actuator link (10) anticlockwise, as it is fixed on closing shaft (11) along with it closing shaft also rotates. As soon as closing shaft (11) rotates closing circuit get collapsed and main spring (12) gets discharged.

[0031] Similarly, while pushing the breaker from maintenance position to disconnected position main spring (12) gets discharged and breaker remains in off condition.

[0032] Figure 3 illustrates a schematic of mechanism-2, in accordance with the subject matter of the present invention.

[0033] Apart from the advantages and benefits mentioned above, other advantages and benefits are mentioned below:
· The present invention solves the problem of spring remains in charge condition while maintenance.
· The present invention solves the problem of dependency of main spring discharge mechanism from main linkages.
· The arrangement is such that it reduces the space requirement for multi turn primary conductor.
· Spring discharge mechanism is directly coupled with closing circuit main shaft so backlash error avoided.
· The present invention provides an independent mechanism without disturbing present actuation process.
· In the present invention, required closing force achieved by breaker movement only, so no need of additional effort.
· Kinematic system of linkages provided in the present invention accomplishes the said function of self-actuated spring discharge.
· Self-Actuating spring discharge mechanism is provided with minimum components.
· Disclosed mechanism has independent mechanism operation without any user interference or input.
· As mechanism is self-actuated, the invention will ensure smooth and reliable working of feature.
· Said arrangement, provided in the present invention, can be utilized without modification for different frame rating of circuit breakers

[0034] It may be understood by the person skilled in that art that, the coupling, joining, fitting of the two components mentioned the present invention may be achieved by any of the existing coupling techniques that may include but not limited to nut and bolt arrangement, gluing, pasting, welding, and the like.

[0035] Although a self actuated spring discharge mechanism of circuit breaker have 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 implementations of the self actuated spring discharge mechanism of circuit breaker.