Description:TECHNICAL FIELD
[0001] The embodiments of the present disclosure generally relates to an arrangement where high magnitude force developed in electrical contacts will be compensated for by their geometrical construction using phenomena of magnetic effects in current conductors.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] As conventionally known, it is necessary for current carrying device (for example like a circuit breaker device) to withstand without interrupting the fault currents flowing through them. Electrical contacts are highly sensitive to electric current. Due to the phenomena of current constriction, repulsive blow-off forces are featured in them in response to the flow of current. The magnitude of these forces is roughly proportional to the square of the current experienced by contact. For normal amplitude around rated current, blow-off forces experienced by contacts are easily absorbed or overcome by use of external mechanical counter force. Vibrations and impact on system due to flow of current and thereby response of electromagnetic forces is also not recognizable. Hence, maintaining contact and retaining electrical continuity without affecting current carrying device is easily achievable.
[0004] At high amplitude currents, blow-off forces within contacts are tremendously higher. To counter these high magnitude blow-off forces preferred option is using bolted contacts, where tightening torque of hardware ensures clamping force against blow-off force and maintains continuity. Another solution to reduce the effect of blow off force is by splitting the current into multiple parallel paths by means of jaw type construction. Splitting of current would result in reduction of blow-off forces by number of parallel branches. This helps in providing counter force arrangement more efficiently.
[0005] Efficiency of external mechanical counter force is impacted by system vibrations, buckling, environmental factors, thermal and chemical impacts. It is also affected by manual inventions like placements during assembly or maintenance. The life of components in compensatory system is derived from its properties, strengths of materials and bonding among them. If anything between it fails to play their role as intended, then intention of compensatory system fails, and the contacts shall be opened. This leads to arcing between contacts and cause permanent damages to current carrying device along with load side equipment. In case of circuit breaker with draw-out provision, breaker racking-in and racking out torque will be increased due to counter force arrangement in compensatory system and weight of compensatory components. It will lead to additional strengthening of components to bear additional stresses on load bearing components. This will be calling for additional manufacturing secondary processes, surface treatments. In turn, it will be realized in terms of overall cost impact of product.
[0006] Hence, to summarize the technical problems as recited above, there is a need for a simple, efficient and improved systems/apparatus/device and methods to counter the blow-off forces experienced between electric current carrying contact.

SUMMARY
[0007] This section is provided to introduce certain objects and aspects of the present invention in a simplified form that are further described below in the detailed description. This summary is not intended to identify the key features or the scope of the claimed subject matter.
[0008] In order to overcome at least few problems associated with the known solutions as provided in the previous section, an object of the present disclosure is to provide a simple, efficient and improved systems/apparatus/device and methods to counter the blow-off forces experienced between electric current carrying contact.
[0009] The invention intends to solve the problem of providing an arrangement where high magnitude force developed in electrical contacts will be compensated for by their geometrical construction using phenomena of magnetic effects in current conductors.
[0010] Accordingly, an aspect of the present invention rules out the dependency on external mechanical compensatory system to counter the blow-off forces experienced between electric current carrying contact. In said invention, geometrical construction of current carrying contacts have been modified such that current in conducting parts of either side contacts are unidirectional with reference to each other. Which in turn experiences attractive Lorentz force between them. These attractive Lorentz forces are in opposing direction to experiencing the blow-off forces between contacts, aiding in maintaining electrical contacts and thereby retaining electrical continuity.
[0011] The present invention describes independency of electrical contacts on external mechanical compensatory systems to retain electrical continuity when system is subjected to current.
[0012] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The accompanying drawings, which are incorporated herein, and constitute a part of this invention, illustrate exemplary embodiments of the disclosed methods and systems in which like reference numerals refer to the same parts throughout the different drawings. Components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Some drawings may indicate the components using block diagrams and may not represent the internal circuitry of each component. It will be appreciated by those skilled in the art that invention of such drawings includes the invention of electrical components, electronic components or circuitry commonly used to implement such components.
[0014] FIGs. 1A-1B illustrates a breaker-assembly, in accordance with an embodiment of the present disclosure.
[0015] FIGs. 2A-2B illustrates exemplary cradle-contact-assembly, in according to embodiments of the present disclosure, according to embodiments of the present disclosure.
[0016] FIG. 2C illustrates an adaptor-assembly, in accordance with an embodiment of the present disclosure.
[0017] FIG. 2D illustrates a cradle-assembly, in accordance with an embodiment of the present disclosure.
[0018] FIGs. 3A-3B illustrates a breaker-assembly and a cradle-assembly in contact with each other, in accordance with an embodiment of the present disclosure.
[0019] The foregoing shall be more apparent from the following more detailed description of the invention.

DETAILED DESCRIPTION
[0020] Various example embodiments will now be described more fully with reference to the accompanying drawings in which only some example embodiments are shown. Specific structural and functional details disclosed herein are merely representative for purposes of describing example embodiments. The present invention, however, may be embodied in many alternate forms and should not be construed as limited to only the example embodiments set forth herein.
[0021] Accordingly, while example embodiments of the invention are capable of various modifications and alternative forms, embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit example embodiments of the present invention to the particular forms disclosed. On the contrary, example embodiments are to cover all modifications, equivalents, and alternatives falling within the scope of the invention. Like numbers refer to like elements throughout the description of the figures.
[0022] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments of the present invention. As used herein, the term “and/or,” includes any and all combinations of one or more of the associated listed items.
[0023] It will be understood that when an element is referred to as being “connected,” or “coupled,” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected,” or “directly coupled,” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between,” versus “directly between,” “adjacent,” versus “directly adjacent,” etc.).
[0024] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments of the invention. As used herein, the singular forms “a,” “an,” and “the,” are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the terms “and/or” and “at least one of” include any and all combinations of one or more of the associated listed items. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0025] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
[0026] Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper”, and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, term such as “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein are interpreted accordingly.
[0027] Although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, it should be understood that these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or section from another region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the present invention.
[0028] As recited above, an object of the present disclosure is to provide a simple, efficient and improved systems/apparatus/device and methods to counter the blow-off forces experienced between electric current carrying contact.
[0029] The invention intends to solve the problem of providing an arrangement where high magnitude force developed in electrical contacts will be compensated for by their geometrical construction using phenomena of magnetic effects in current conductors.
[0030] Accordingly, an aspect of the present invention rules out the dependency on external mechanical compensatory system to counter the blow-off forces experienced between electric current carrying contact. In said invention, geometrical construction of current carrying contacts have been modified such that current in conducting parts of either side contacts are unidirectional with reference to each other. Which in turn experiences attractive Lorentz force between them. These attractive Lorentz forces are in opposing direction to experiencing the blow-off forces between contacts, aiding in maintaining electrical contacts and thereby retaining electrical continuity.
[0031] The present invention describes independency of electrical contacts on external mechanical compensatory systems to retain electrical continuity when system is subjected to current.
[0032] Accordingly, embodiments of the present invention primarily consists of two bodies, a breaker-assembly and a cradle-assembly. In short circuit protection devices (SCPD), The breaker-connector of the breaker-assembly is connected to the breaker contact and cradle-assembly is cradle current carrying component. Breaker-connector and breaker-finger are the current carrying components of the breaker-assembly. Cradle-finger, Flexible-link, Adaptor, and external connector are the current carrying components of the cradle-assembly. The flexible link is made up of flexible conductor element and provides flexibility when contacts are made. The breaker-finger and cradle-finger have multiple fingers in order to make current splitting.
[0033] In order to establish electrical contact through the current carrying device, the breaker-fingers of the breaker-assembly are to be encountered with cradle-fingers of cradle-assembly by butting of contact surfaces among two bodies. To maintain continuity of electrical supply and retain electrical contact between cradle-finger and breaker-finger, counter force is governed through compensatory system. Compensatory system encompasses a spring, which is assembled between Cradle-finger and flexible- link and also between flexible-link and adaptor, such that overtravel of cradle-finger because of the flexibility provided by the flexible-link, aids the contact pressure necessary to maintain it in normal conditions of current.
[0034] When trade of current between cradle-finger and breaker- finger, repulsive blow-off (holm) force is generated due to current constrictions at contact regions. At normal amplitude around rated current, magnitude of blow-off force is easily tackled through the spring of compensatory system. But at a higher amplitude, blow-off force magnitudes are considerably higher, and they are more prone to repel. In said invention, current directions in cradle-finger and breaker-finger are parallel to each other and also in same direction due to its geometrical construction. Therefore, the current flowing in in two parallel conductors produces attraction force. Hence, attractive Lorentz forces are triggered between cradle-finger and breaker-finger. This generated attractive Lorentz force is in opposite in direction to that of repulsive blow-off force between cradle-finger and breaker-finger. Attractive Lorentz force aids in counterforce of the spring in compensatory system. The magnitude of repulsive Lorentz force depends on length of cradle-finger and breaker-finger.
[0035] In the disclosed invention, geometry for contact placement does not allow contact repulsion of butt contacts at higher magnitude fault currents. Thereby contacts remain intact and electrical supply continuity shall be maintained.
[0036] The present invention, attractive Lorentz force aids counter force which in turn improves safety by reducing stress on external compensatory system. It helps in cost optimization by reducing copper consumption.
[0037] In currently available electric current carrying devices with draw-out requirement, butt contacts are never found preferable. Manufacturers of current carrying devices have been providing at most importance for protection of load system and operability of current carrying device. If formed arc during contact repulsion is not properly channelized for arc extinction, then it will burn and blast the current carrying device along with structures of draw-out assembly. This is dangerous for vicinity personnel and surrounding property to current carrying device. This problem has been tackled by providing multiple current splits in the form of jaw type contacts. Generally, the direction of repulsive blow-off force in jaw type contacts is orthogonal to movement of contact while separation or repulsion. As current splitting is in quite high number of branches, it reduces the current amplitude per contact by number of branches and thereby reduces magnitude of blow-of force. Reduction in magnitude of blow-off force is taken care of by clamping force and external counterforce by compensatory system. But it involves high consumption of copper and thereby high cost. As compensatory spring forces are high in magnitude, required rack-in force is also high. Which in turn results in high stress on structure and components involved in racking-in and racking-out device contact. This results in excessive strengthening of components, which results in increased costs.
[0038] The invention will now be explained from the perspective of various figures:
[0039] FIGs. 1A-1B illustrates a breaker-assembly, in accordance with an embodiment of the present disclosure.
[0040] FIGs. 2A-2B illustrates exemplary cradle-contact-assembly, in according to embodiments of the present disclosure, according to embodiments of the present disclosure.
[0041] FIG. 2C illustrates an adaptor-assembly, in accordance with an embodiment of the present disclosure.
[0042] FIG. 2D illustrates a cradle-assembly, in accordance with an embodiment of the present disclosure.
[0043] FIGs. 3A-3B illustrates a breaker-assembly and a cradle-assembly in contact with each other, in accordance with an embodiment of the present disclosure.
[0044] Below is the list of components used in the figures
1. Breaker-assembly
11. Breaker-finger
12. Breaker-connector
13. Breaker-nutplate
14. Breaker-bolts
2. Cradle-assembly
2a. Cradle-contact-assembly
21. Cradle-finger
22. Finger-bracket
23. Fastners
24. Flexible-link
25. Cradle-bolts
26. Cradle-nutplate
2b. Adaptor-assembly
27. Adaptor-bracket
28. Adaptor
29. External-connector
30. Springs
[0045] As shown in figures, the invention consists of Breaker-assembly 1 and Cradle-assembly 2. Breaker-assembly 1 consists of Breaker-Finger 11, Breaker-connector 12, Breaker-nut plate 13 and Breaker-bolts 14. The Breaker-Finger 11 and Breaker-connector 12 are connected through Breaker-nutplate 13 and Breaker-bolts 14. This Breaker-assembly 1 is a part of short circuit protective device as its terminals are connected to the breaker-connector 12.
[0046] Cradle-assembly 2 forms a part of the cradle. Cradle-assembly 2 consists of Cradle-contact-assembly 2a , adaptor-assembly 2b, external-connector 29, Springs 30 and cradle-bolts 25. The cradle -contact-assembly 2a consists of Cradle-finger 21, Finger-bracket 22, Flexible-link 24. The Finger-bracket 22 is mounted over the Cradle-finger 21 using Fasteners 23. The flexible-link 24 is also connected to the cradle-finger 21 using cradle-nut plate 26 and cradle-bolts 25. The adaptor-assembly 2b consists of Adaptor 28 and adaptor-bracket 27. The Adaptor-bracket 27 is mounted over the adaptor 28 using Fasteners 23. The flexible-link 24 of Cradle-contact-assembly 2a, the adaptor 28 of Adaptor-assembly 2b and external-connector 29 are connected together through cradle-bolts 25 and cradle-nut plate 26. The flexible-link 24 is actually a flexible current carrying medium. The cradle-finger 21 is always kept at a tension using Springs 30 connected in the Cradle-assembly 2. The springs 30 are inserted in the Cradle-bolts 25 and are rested between Cradle-nut plate 26 and finger-bracket 22 and between cradle-nut plate 26 and adaptor-bracket 27. The entire cradle-assembly 2 is a part of the Cradle and the external connections are made using the external-connector 29. The Springs 30 provide the necessary contact pressure and the flexible-link 24 is the flexible member.
[0047] When the cradle-assembly 2 and breaker-assembly 1 are pressed against each other, electrical contacts are formed between them i.e., breaker-finger 11 and cradle-finger 21 will come in contact. The flexible-link 24 provides the required flexibility and the Springs 30 provides the necessary contact pressure. As the breaker-finger 11 and cradle-finger 21 will comes in contact, parallel current paths are established. When current is injected into the system, because of the parallel current paths developed between breaker-finger 11 and cradle-finger 21 and by design the current flows in the same direction and this develops a Lorentz force of attractive in nature. Whereas repulsive blow-off force develops at contact meeting surfaces of breaker-finger 11 and cradle-finger 21 due to the phenomena of current constriction. At higher amplitudes of short circuit current and inrush currents, magnitude of blow-off forces at electrical contact are tremendously higher. Compensating them through external mechanical means like spring alone is quite difficult. As Lorentz force is directly proportional to the square of current through parallel current carrying conductor, at higher amplitudes, magnitude of Lorentz force is also higher. So the developed Lorentz force between breaker-finger 11 and cradle-finger 21 which is attractive in nature because of the design compensates the blow-off force at contact. Hence the load on mechanical compensatory system is reduced.
[0048] In an embodiment, a current carrying device (for example a circuit breaker) is disclosed. The device includes a breaker-assembly (1) having a breaker-finger (11), and a cradle-assembly (2) having a cradle-contact-assembly (2a) and an adaptor-assembly (2b).
[0049] The device includes an adaptor (28) of the adaptor-assembly (2b) having an adaptor- bracket (27) that allows a first end of a cradle-finger (21) of the cradle-contact-assembly (2a) to slide in the adaptor-bracket (27).
[0050] The device also includes a second end of a cradle-finger (21) having a finger-bracket (22) that allows the second end of a cradle-finger (21) to be coupled to the adaptor (28).
[0051] The adaptor (28) includes a flexible-link (24) provided such that the finger-bracket (22) couples with the adaptor (28) through the flexible-link (24), and each of the finger-bracket (22) and the adaptor-bracket (27) having one or more springs (30) separating the adaptor (28) from the cradle-finger (21).
[0052] The breaker-finger (11) and cradle-finger (21) are adapted to contact each other to form an electrical contact for carrying current such that the flexible-link (24) provides a flexibility to the electrical contact and the one or more springs (30) provides a contact pressure to the electrical contact.
[0053] In an exemplary embodiment, the current carrying device is a circuit breaker.
[0054] In an exemplary embodiment, the breaker-assembly (1) consists of a breaker-connector (12), a breaker-nut plate (13) and one or more breaker-bolts (14), the breaker-finger (11) and the breaker-connector (12) are connected through breaker-nut plate (13) and the one or more breaker-bolts (14).
[0055] In an exemplary embodiment, the finger-bracket (22) is mounted over the cradle-finger (21) using one or more fasteners (23).
[0056] In an exemplary embodiment, the flexible-link (24) is also connected to the cradle-finger (21) using the cradle-nut plate (26) and the one or more cradle-bolts (25).
[0057] In an exemplary embodiment, the adaptor-bracket (27) is mounted over the adaptor (28) using the one or more fasteners (23).
[0058] In an exemplary embodiment, the flexible-link (24), the adaptor (28) and an external-connector (29) are connected together through the one or more cradle-bolts (25) and the cradle-nut plate (26).
[0059] In an exemplary embodiment, the flexible-link (24) is a flexible current carrying medium.
[0060] In an exemplary embodiment, the one or more springs (30) are inserted in the one or more cradle-bolts (25) and are rested between the cradle-nut plate (26) and the finger-bracket (22) and between the cradle-nut plate (26) and the adaptor-bracket (27).
[0061] In an exemplary embodiment, when the electrical contact for carrying current is formed, a repulsive blow-off force is developed at contact meeting surfaces of the breaker-finger (11) and the cradle-finger (21) due to current constriction, wherein the repulsive blow-off force is compensated by Lorentz force generated between beaker-finger (11) and cradle-finger (21).
[0062] What are described above are merely preferred embodiments of the present invention, and are not to limit the present invention; any modification, equivalent replacement and improvement within the principle of the present invention should be included in the protection scope of the present invention.
[0063] The example embodiment or each example embodiment should not be understood as a restriction of the invention. Rather, numerous variations and modifications are possible in the context of the present disclosure, in particular those variants and combinations which can be inferred by the person skilled in the art with regard to achieving the object for example by combination or modification of individual features or elements or method steps that are described in connection with the general or specific part of the description and are contained in the claims and/or the drawings, and, by way of combinable features, lead to a new subject matter or to new method steps or sequences of method steps, including insofar as they concern production, testing and operating methods.
[0064] References back that are used in dependent claims indicate the further embodiment of the subject matter of the main claim by way of the features of the respective dependent claim; they should not be understood as dispensing with obtaining independent protection of the subject matter for the combinations of features in the referred-back dependent claims. Furthermore, with regard to interpreting the claims, where a feature is concretized in more specific detail in a subordinate claim, it should be assumed that such a restriction is not present in the respective preceding claims.
[0065] Since the subject matter of the dependent claims in relation to the prior art on the priority date may form separate and independent inventions, the applicant reserves the right to make them the subject matter of independent claims or divisional declarations. They may furthermore also contain independent inventions which have a configuration that is independent of the subject matters of the preceding dependent claims.
[0066] Further, elements and/or features of different example embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims.
[0067] Example embodiments being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
, Claims:1. A current carrying device comprising:
a breaker-assembly (1) having a breaker-finger (11); and
a cradle-assembly (2) having a cradle-contact-assembly (2a) and an adaptor-assembly (2b), wherein:
an adaptor (28) of the adaptor-assembly (2b) having an adaptor- bracket (27) that allows a first end of a cradle-finger (21) of the cradle- contact-assembly (2a) to slide in the adaptor-bracket (27); and
a second end of a cradle-finger (21) having a finger-bracket (22) that allows the second end of a cradle-finger (21) to be coupled to the adaptor (28);
wherein the adaptor (28) includes a flexible-link (24) provided such that the finger-bracket (22) couples with the adaptor (28) through the flexible-link (24); and
wherein each of the finger-bracket (22) and the adaptor-bracket (27) having one or more springs (30) separating the adaptor (28) from the cradle-finger (21); and
wherein the breaker-finger (11) and cradle-finger (21) are adapted to contact each other to form an electrical contact for carrying current such that the flexible-link (24) provides a flexibility to the electrical contact and the one or more springs (30) provides a contact pressure to the electrical contact.

2. The current carrying device as claimed in claim 1, wherein the current carrying device is a circuit breaker.

3. The current carrying device as claimed in claim 1, wherein the breaker-assembly (1) consists of a breaker-connector (12), a breaker-nut plate (13) and one or more breaker-bolts (14), the breaker-finger (11) and the breaker-connector (12) are connected through breaker-nut plate (13) and the one or more breaker-bolts (14).
4. The current carrying device as claimed in claim 1, wherein:
the finger-bracket (22) is mounted over the cradle-finger (21) using one or more fasteners (23);
the flexible-link (24) is also connected to the cradle-finger (21) using the cradle-nut plate (26) and the one or more cradle-bolts (25); and
the adaptor-bracket (27) is mounted over the adaptor (28) using the one or more fasteners (23).

5. The current carrying device as claimed in claim 1, wherein the flexible-link (24), the adaptor (28) and an external-connector (29) are connected together through the one or more cradle-bolts (25) and the cradle-nut plate (26).

6. The current carrying device as claimed in claim 1, wherein the flexible-link (24) is a flexible current carrying medium.

7. The current carrying device as claimed in claim 1, wherein the one or more springs (30) are inserted in the one or more cradle-bolts (25) and are rested between the cradle-nut plate (26) and the finger-bracket (22) and between the cradle-nut plate (26) and the adaptor-bracket (27).

8. The current carrying device as claimed in claim 1, wherein when the electrical contact for carrying current is formed, a repulsive blow-off force is developed at contact meeting surfaces of the breaker-finger (11) and the cradle-finger (21) due to current constriction, wherein the repulsive blow-off force is compensated by a Lorentz force generated between beaker-finger (11) and cradle-finger (21).