OBJECTS OF THE INVENTION
[0015] A general object of the present disclosure is to provide for a simple, compact and economical angled contact finger that obviates shortcomings encountered with conventional finger assembly for circuit breakers.
[0016] An object of the present disclosure is to provide an improved profile for contact fingers that ensures more uniform current sharing among fingers in a multiple contact finger or conductor contact system for a multiphase circuit breaker or switching devices in order to obviate undesired action therebetween.
[0017] An object of the present disclosure is to provide substantial dynamic stability against tilting and sliding torques acting on contact finger(s) on account of their angled profile.
[0018] Yet another object of the present disclosure is to obviate losses from temperature rise, fault current breaking, among others, by application of angled contact fingers in a circuit breaker.
[0019] Yet another object of the present disclosure is to improve the current withstand, making and breaking performances or Icw, Icm and Icu performances and current carrying performances by application of angled contact fingers in a circuit breaker.

SUMMARY
[0020] Aspects of the present disclosure generally relate to the field of circuit breakers. In particular, the present disclosure pertains to an improved profile of a finger contact assembly. More specifically, the present disclosure relates to application of finger contact assemblies, with and without improved profile, in circuit breakers so as to obviate efficiency losses, among others.
[0021] In an aspect, the present disclosure provides an angled contact finger (ACF) that can include a profile that varies along two-axes of the ACF, wherein one axis of the two-axes can be along width while another axis can be along its cross-section, wherein the profile along the one axis can be an inverse mirror-image or an approximately similar shaped inverse mirror-image at both sides of a support pin of the ACF, wherein imaginary plane of cut-out portion of the profile at the both sides can make an angle greater than 90 degrees with each other and the two angles can be same or different as per requirement.
[0022] In an aspect, profile along one axis tapers initially along an angle and thereafter moves parallel to original vertical side of ACF, wherein tapering along the angle extends up to around halfway of the width of the ACF. The cut-out portion of the profile can be substantially opposite to the fulcrum hole (130) for the support pin of the ACF, and at the upper side it is on the opposite of the contact button (132) and on the lower side it is along the same side as that of the contact button (132).
[0023] In an aspect, the present disclosure provides a circuit breaker (CB) with one or more contact fingers along with at least one angled contact finger (ACF) that can be configured with a profile that varies along two-axes of the at least one ACF, wherein one axis of the two-axes can be along width while another axis can be along its cross-section, wherein the one or more contact fingers can be placed between the at least one ACF, that, in turn, can be present at one or more ends of the CB so as to obtain balanced distribution of current.
[0024] In an aspect, width (w1) and cross section (d1) of at least one ACF can be less than average values of width (w2) and cross section (d2), respectively, of the one or more contact fingers.
[0025] In an aspect, for “n” number of one or more contact fingers in a pole or in a contact assembly for each phase and at least one ACF taken together, ACF can be positioned at 1st, 2nd, (n-1)th, and nth position (or the side most fingers of both sides of a pole or multiple conductor contact assembly) in a pole or in a contact assembly for each phase inside CB.
[0026] In an aspect, profile along one axis can taper initially along an angle and thereafter moves parallel to original vertical side of ACF, wherein tapering along the angle extends up to around halfway of the width of the ACF.
[0027] In an aspect, cut-out of undesired portion from one or more contact fingers along the profile of at least one ACF can be performed so as to obtain the at least one ACF.
[0028] 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
[0029] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0030] FIGS. 1A and 1B illustrate exemplary side and perspective views of angled contact finger (ACF) in accordance to an embodiment of the present disclosure.
[0031] FIG. 1C illustrates exemplary side view of ACFs along with one or more contact fingers in accordance to an embodiment of the present disclosure.
[0032] FIGS. 1D and 1E illustrate exemplary isometric views of ACFs along with one or more contact fingers in accordance to an embodiment of the present disclosure.
[0033] FIG. 2A illustrates exemplary side cross-sectional view of ACFs in pole assembly in accordance to an embodiment of the present disclosure.
[0034] FIG. 2B illustrates exemplary front view of ACFs in pole assembly in accordance to an embodiment of the present disclosure.
[0035] FIGS. 2C and 2D illustrate exemplary perspective views of ACFs in pole assembly in accordance to an embodiment of the present disclosure.
[0036] FIG. 3A illustrates exemplary front view of a breaker assembly in accordance to an embodiment of the present disclosure.
[0037] FIG. 3B illustrates exemplary side cross-sectional view of a part of a breaker assembly along with ACFs and one or more contact fingers in accordance to an embodiment of the present disclosure.
[0038] FIG. 4 illustrates exemplary side cross-sectional view of a part of a breaker assembly in accordance to an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0039] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0040] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0041] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0042] Embodiments of the present disclosure generally relate to the field of circuit breakers. In particular, the present disclosure pertains to an improved profile of a finger contact assembly. More specifically, the present disclosure relates to application of finger contact assemblies, with and without improved profile, in circuit breakers so as to obviate efficiency losses, among others.
[0043] As used herein, a person skilled in the relevant art would appreciate that “multiple conductor contact assembly” or “multiple finger contact assembly” or “circuit breaker” or “switch gear”, as used interchangeably throughout the present disclosure, refers to an assembly/system used in electrical tripping operations by action of at least one conductor (hereinafter, finger or finger assembly) on detection of a undesired condition such as over rated conditions (say high current).
[0044] FIGS. 1A and 1B illustrate exemplary side and perspective views of angled contact finger (ACF) 100, in accordance to an embodiment of the present disclosure, where the ACF 100 can include a profile (110a or 110b and 120a or 120b) that varies along two-axes thereof, wherein one axis of the two-axes can be along width while another axis can be along its cross-section, wherein the profile along the one axis can be an inverse mirror-image at both sides or an approximately similar shaped inverse mirror-image of a fulcrum pin 130 (alternatively, fulcrum point) of the ACF 100, wherein imaginary plane of cut-out portion of the profile at the both sides can make an angle greater than 90 degrees with each other. The cut-out portion of the profile can be substantially opposite to the support pin () of the ACF and at the upper side is on the opposite of the contact button and on the lower side it is along the same side of the contact button.
[0045] In an aspect, profile along one axis tapers (shown as 110a or 110b depending upon top or bottom) initially along an angle and thereafter moves parallel (shown as 120a or 120b, depending upon taper) to original vertical side of ACF 100, wherein tapering along the angle extends up to around halfway (about fulcrum pin 130) of the width of the ACF 100.
[0046] In an aspect, profile of ACF 100, as illustrated by FIGS. 1A and 1B, can ensures two particular and specific cut or blank profile or portion (110a, 120a pair or 110b, 120b pair) in alternate or diagonal position width wise on both side of fulcrum point 130 on the ACF 100. One cut or blank profile can be behind contact button (132) and above the fulcrum point/fulcrum hole 130 on ACF 130 and the other cut or blank profile can be on the same side of the contact button (132)and partially or completely below the fulcrum point/fulcrum hole 130 on the ACF 130. The blank or cut portion can be such that it forms an angle between the two cut plane that is > 90º. Notably, the angle can vary as per requirement but it is generally >90º. Due to such a profile current flows through this angled path near the fulcrum hole 130 and the magnetic flux linkage and distribution pattern results in the additional finger closing force or closing torque acting against the repulsion force or opening torque.
[0047] FIG. 1C illustrates exemplary side view while FIGS. 1D and 1E illustrate exemplary isometric views of ACFs 100 along with one or more contact fingers 100’ (alternatively, contact finger 1001) in accordance to an embodiment of the present disclosure. In an aspect, cut-out of undesired portion from one or more contact fingers 100’along the profile of at least one ACF 100 can be performed so as to obtain the at least one ACF 100. In an aspect, for “n” number of one or more contact fingers in a pole or in a contact assembly for each phase and at least one ACF taken together, ACF with lower average cross section than the other fingers in the same pole can be positioned at 1st, 2nd, (n-1)th, and nth position (or the side most fingers [single or multiple] of both sides of a pole or multiple conductor contact assembly) in a pole or in a contact assembly for each phase.
[0048] In an aspect, ACF 100 (p in numbers) in a phase or in a pole can be of lower average cross section (say A1) as per requirement while other contact finger 1001 (n-p in numbers, since total number of both fingers is n, when taken together) can be of comparatively higher average cross section (say A2) where A2 > A1. Further, in an alternate aspect, each finger in a pole or in a phase in a multiphase circuit breaker can be of different cross section like a1, a2, a3…..an where a1?a2?a3?……?an. Notably, in a multiphase circuit breaker for each phase or each pole, the lesser cross section in finger 100 (i.e. ACF) can be achieved by reducing the width thereof while remaining fingers 100’ (i.e. contact fingers) in pole can have constant thickness.
[0049] Notably, in a multiphase circuit breaker for each phase or each pole, the lesser cross section in finger 100 (i.e. ACF) can be achieved by reducing the width thereof while remaining fingers 100’ (i.e. contact fingers) in pole can have constant thickness. For instance, for fingers (n in number) with equal finger thickness in a pole or in a phase in a multiphase circuit breaker, construction wise and position wise any finger and any number of ACF fingers 100 (p in number) in a phase or in a pole can be of lower average cross section A1 by having lesser finger width B1 as per requirement and other (n-p) number of contact fingers 100’ can be of comparatively higher average cross section A2 by having higher finger width B2 where A2>A1 and B2>B1. Also, alternatively, as per requirement each finger in a pole or in a phase in a multiphase circuit breaker can be of different cross section like a1, a2, a3…..an and a1?a2?a3?……?an. For this for n fingers with equal finger thickness in a pole or in a phase in a multiphase circuit breaker, as per requirement each finger in a pole or in a phase in a multiphase circuit breaker can be of different cross section a1, a2, a3…..an where a1?a2?a3?……?an by having corresponding different finger width like b1, b2, b3……bn where b1?b2?b3?……?bn.
[0050] FIG. 2A illustrates exemplary side cross-sectional view of ACFs 100 and one or more contact fingers 100’ in pole assembly 200 in accordance to an embodiment of the present disclosure. As illustrated, a pole connector can be utilized for securing pole cage 230 to desired part of circuit breaker or the like. Further, FIG. 2B illustrates exemplary front view of ACFs 100 in pole assembly 200 in accordance to an embodiment of the present disclosure.
[0051] FIG. 2C and 2D illustrate exemplary perspective views of ACFs 100 and one or more contact fingers 100’ in pole assembly 200 in accordance to an embodiment of the present disclosure. As illustrated, arcing Contact 134 and main contact 132 can be present towards top side of both ACF 100 as well as contact finger 100’, both of which can include a fulcrum pin 130 for ease of their movement, while being supported by a support pin 238, inside pole cage 230 (preferably made up of metal), which is supported on bottom terminal 270, wherein the pole cage and bottom terminal 270 can be secured together due to the presence of a pin 232 (made up of brass in some embodiments). Further, both of these units, independently, can be readily constrained in their movement by presence of a spring 236 that can be housed inside a spring holder 234.
[0052] FIG. 3A illustrates exemplary front view of a breaker assembly 300 in accordance to an embodiment of the present disclosure. FIG. 3B illustrates exemplary side cross-sectional view 350 of a part of a breaker assembly 300 (or circuit breaker) along with ACFs 100 and one or more contact fingers 100’ in accordance to an embodiment of the present disclosure. In an aspect, the present disclosure provides a circuit breaker (CB) 300 with one or more contact fingers 100’ along with at least one angled contact finger (ACF) 100 that can be configured with a profile (110a or 110b and 120a or 120b) that varies along two-axes thereof, wherein one axis of the two-axes can be along width while another axis can be along its cross-section, wherein the one or more contact fingers 100’ can be placed between the at least one ACF 100, that, in turn, can be present at one or more ends of the CB 300 so as to obtain balanced distribution of current.
[0053] In an aspect, width (w1) and cross section (d1) of at least one ACF 100 can be less than average values of width (w2) and cross section (d2), respectively, of the one or more contact fingers 100’.
[0054] In an aspect, for “n” number of one or more contact fingers in a pole or in a contact assembly for each phase and at least one ACF taken together, ACF with lower average cross section than the other fingers in the same pole can be positioned at 1st, 2nd, (n-1)th, and nth position (or the side most fingers [single or multiple] of both sides of a pole or multiple conductor contact assembly) in a pole or in a contact assembly for each phase inside CB 300.
[0055] In an aspect, profile along one axis can taper initially along an angle and thereafter moves parallel to original vertical side of ACF, wherein tapering along the angle extends up to around halfway of the width of the ACF.
[0056] FIG. 4 illustrates exemplary side cross-sectional view 400 of a part of a breaker assembly 300 in accordance to an embodiment of the present disclosure. As illustrated, main sections of the breaker assembly 300 can include a mechanism 410 that encloses working mechanism of setup, and arc chute 430 that is adjacent to arc runner 420. Further, top terminal 450 and bottom terminal 470 are in proximity of ACF 100 and contact fingers 100’ so as to selectively form contact (by interaction of arching contact 134 and/or main contact 132 with the top terminal 450 so as to complete the circuit as per need) therebetween, wherein the ACF 100 can be present at one or more sides (while this figures illustrates only one side) of the breaker assembly 400 while covering one or more contact fingers 100’ therebetween.
[0057] In a multiphase circuit breaker for each phase or each pole, the lesser cross section in finger (i.e. ACF 100) can be achieved by reducing the thickness of the finger than the remaining fingers (i.e. contact finger 100’) in the pole having finger width constant in all the fingers. For this for n fingers with equal finger width in a pole or in a phase in a multiphase circuit breaker, construction wise and position wise any finger and any number of ACF 100 (p in number) in a phase or in a pole can be of lower average cross section A1 by having lesser finger thickness C1 as per requirement and other contact finger 100’ (n-p in number) can be of comparatively higher average cross section A2 by having higher finger width C2 where A2>A1 and C2>C1. Also, alternatively, as per requirement each finger in a pole or in a phase in a multiphase circuit breaker can be of different cross section like a1, a2, a3…..an and a1?a2?a3?……?an. For this for n fingers with equal finger width in a pole or in a phase in a multiphase circuit breaker, as per requirement each finger in a pole or in a phase in a multiphase circuit breaker can be of different cross section a1, a2, a3…..an where a1?a2?a3?……?an by having corresponding different finger thickness like c1, c2, c3……cn where c1?c2?c3?……?cn.
[0058] In an aspect, for a multiphase circuit breaker for each phase or each pole, the different cross section in fingers can be achieved by varying the thickness or the width of the finger or varying both simultaneously or by having any probable finger width and thickness combinations. For this for n fingers in a pole or in a phase in a multiphase circuit breaker, as per requirement each finger in a pole or in a phase in a multiphase circuit breaker can be of different cross section a1, a2, a3…..an where a1?a2?a3?……?an by having corresponding different finger thickness and different finger width or by having any probable finger width and thickness combinations. In a multiphase circuit breaker for each phase or each pole, the different cross section in any finger can also be achieved by varying the thickness or the width of the finger vertically or along the length wise of the finger or varying both simultaneously or by having any probable finger width and thickness combinations vertically or along the length wise of the finger. All such combination and/or modifications have been well thought of and can be implemented by a person having ordinary knowledge in the art and therefore well within the scope of the present disclosure.
[0059] Thus, the present disclosure provides an angled contact finger (ACF) that reduces the dynamic instability of contact fingers, and increases efficiency, while resulting in an overall reduction in operating losses, among other benefits, for a multiple finger contact assembly. Thus, the present disclosure provides an angled contact finger (ACF) and for “n” number of one or more contact fingers in a pole or in a contact assembly for each phase and at least one ACF taken together, ACF can be positioned at 1st, 2nd, (n-1)th, and nth position (or the side most fingers of both sides of a pole or multiple conductor contact assembly) in a pole or in a contact assembly for each phase inside CB that ensures, the increase in the resistivity in the side most fingers with lesser cross section and due to the constructional feature of each pole having fingers with different average cross sections and the particular angled shaped finger profile, the variation in self and mutual inductance and the variation in distribution of the magnetic field lines due to rated or fault current and corresponding eddy current and the intra phase and inter phase proximity effect leads to the electromagnetic force and ultimately the electromagnetic torque acts such a way that the closing force or torque against the electromagnetic repulsion force or torque increases and a comparatively lesser current pass through that finger and to balance the phase current other fingers with higher average cross section carries comparatively higher current than the current, which otherwise could have been flown if all the fingers in a phase in a multiphase circuit breaker would have same cross section. Ultimately it helps in reducing the magnitude of the maximum instantaneous current seen by any single finger in a phase in a full cycle of the current wave form so that current shared by each finger in a phase tends more towards the average current distribution. It helps in better current sharing by reducing the current peak seen by that finger in which the highest peak current flows and by increasing the current in such a finger in which comparatively lower peak current flows for a full cycle current waveform. The same effect can be achieved by variation in the self-inductance, mutual inductance of a finger in a phase or in a pole in a multiphase circuit breaker by any probable means and variation in magnetic field distribution pattern by any probable means, which leads to a comparatively lesser current pass through that finger and to balance the phase current, other fingers with higher average cross section carries comparatively higher current than the current, which otherwise could have been flown if all the fingers in a phase in a multiphase circuit breaker carries equal current. It helps in better current sharing by reducing the current peak seen by that finger in which the highest peak current flows and by increasing the current in such a finger in which comparatively lower peak current flows for a full cycle current waveform. The particular profile of the ACF or the finger ensures the magnetic flux linkage and flux pattern such that for a current flowing through it, the electromagnetic force and ultimately the electromagnetic torque acts such a way that the closing force or torque against the electromagnetic repulsion force or torque increases and thus it improves the dynamic stability of the finger and hence improves the breaker performance in Icw, Icm and in fault clearing.
[0060] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.