Description:TECHNICAL FIELD
[0001] The present disclosure relates generally to electrical contact devices. In particular, the present disclosure relates to an electrical contact device with blow-off compensation through magnetic repulsive force.

BACKGROUND
[0002] Blow-off forces are developed in electrical contacts due to current constriction, i.e. build-up of electrical pressure due to constriction or restrictions during the flow of current along an electrical system. This can occur when there is a high voltage or current passing through the contacts, or when the contacts are not properly aligned and in-turn have insufficient contact pressure. Blow offs can cause serious problems in electrical systems, including equipment damage, reduced system efficiency, and the risk of electrical fires. They can also cause disruptions in power supply, leading to outages and other issues.
[0003] 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. However, at higher amplitudes of short circuit current and/or inrush currents, magnitude of such blow-off forces may be tremendously higher where compensating for blow-off forces through mechanical compensatory means may not be adequate. 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 into reduction of blow-off forces by number of parallel branches.
[0004] 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, viz. strength of materials and bonding between them. However, if any component fails, the entire electrical contact needs to be disassembled and replaced. Further, in cases of circuit breaker with draw-out provision, breaker racking-in and racking out torque will need to be increased due to counter force arrangement in compensatory system and weight of compensatory components, thereby resulting in increased requirements for additional strengthening of components to bear said additional stresses on load bearing components. This will create a need for additional manufacturing secondary processes and surface treatments, thereby increasing the overall cost of product.
[0005] In currently available electric current carrying devices with draw-out requirement, butt contacts are never found preferable. Manufacturers of current carrying device have been providing at most importance for protection of load system and operability of current carrying device. If arc formed during contact repulsion is not properly channelized for arc extinction, it will burn and combust the current carrying device along with structures of draw-out assembly. This is dangerous for personnel in its vicinity and property surrounding the current carrying device. This problem has been tackled by providing multiple current splits in the form of jaw type contacts. Generally, direction of repulsive blowoff force in jaw type contact 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-off force. Reduction in magnitude of blow-off force is taken care by clamping force and external counterforce by compensatory system. But it involves high consumption of copper and, in-turn, high cost. As compensatory spring forces are high in magnitude, required rack-in force is also high., which results in high stress put on structure and components involved in racking-in and racking-out device contact. This results into excessive strengthening of components, which results in increased cost.
[0006] There is, therefore, a need for an electrical contact device with blow-off force compensation. Furthermore, there is a need for an electrical contact device with blow-off force compensation means that is cost effective, is simple to manufacture, and is reliable.

OBJECTS OF THE INVENTION
[0007] An object of the present disclosure is to provide blow-off/Holm force compensation through magnetic repulsion between two parallel current carrying conductors.
[0008] Another object of the present disclosure is to reduce the length of the current path with this arrangement.
[0009] Another object of the present disclosure is to reduce the number of electrical joints.
[0010] Another object of the invention is to maintain sustained contact between the contact surface and the at least one finger plate, even during high amplitude currents.
[0011] Another object of the invention is to improve safety by reducing stress on external compensatory systems.
[0012] Another object of the invention is to optimize costs by reducing copper consumption.
[0013] Yet another object of the present disclosure is to reduce the number of components as compared to conventional jaw contacts.
[0014] The other objects and advantages of the present invention will be apparent from the following description when read in conjunction with the accompanying drawings, which are incorporated for illustration of the preferred embodiments of the present invention and are not intended to limit the scope thereof.

SUMMARY
[0015] Aspects of the present disclosure generally to electrical contact devices. In particular, the present disclosure relates to an electrical contact device with blow-off compensation through magnetic repulsive force.
[0016] In an aspect, an electrical contact device with blow-off force compensation, may include an adapter base configured between an adapter pin at one end of said adapter base and at least one terminal pin at the other end of said adapter base, said adapter base configured allow current to flow between the adapter pin and the at least one terminal pin. Further, the device may also include at least one finger plate configured to allow current to flow between a contact surface and one of the at least one terminal pin such that direction of flow of current through said at least one finger plate may be opposite to the direction of flow of current flowing through the adapter base to generate a repulsive force that causes the at least one finger plate to repel away from the adapter base and push said at least one finger plates towards the contact surface, thereby compensating the blow-off force from the contact surface and ensuring sustained contact between the contact surface and the at least one finger plate.
[0017] In an embodiment, more than one finger plates are rotatably configured to each of the at least one terminal pins in the device.
[0018] In an embodiment, the at least one finger plate may be rotatably configured to the at least one terminal pin between a pressure disc and a nut plate with the pivot point as an axis of rotation, said pressure disc and said nut plate configured to securely engage the at least one finger plate to the at least one terminal pin while ensuring said at least one finger plate rotates freely.
[0019] In an embodiment, the repulsive force generated by flowing current between the at least one finger plate and the adapter base in opposite direction may be a Lorentz force generated in a direction that may be opposite to the blow-off force from the contact surface.
[0020] In an embodiment, magnitude of the repulsive force generated may be optimizable by adjusting length of the at least one finger plate, height of adapter base, strength of the currents, the distance and the orientation between the at least one finger plates relative to the adapter base.
[0021] In an embodiment, the device further comprises a spring configured to a side on the adapter base that may be opposite to the adapter pin, said spring configured to bias the at least one finger plate to remain in contact with the contact surface and mechanically compensate blow-off forces.
[0022] In an embodiment, the spring may be selected from the group comprising compression springs, torsion springs or leaf springs.
[0023] In an embodiment, the spring may be configured to bias the at least one finger plate via a spring holder configured on a spring arrester of each of the at least one finger plate.
[0024] 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
[0025] 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.
[0026] FIG. 1 illustrate exemplary representations of the disclosed electrical contact device with blow-off force compensation, according to embodiments of the present disclosure.
[0027] FIG. 2A and 2B illustrate exemplary representations of an adapter assembly of the disclosed electrical contact device with blow-off force compensation, according to embodiments of the present disclosure.
[0028] FIG. 3 illustrate exemplary representations of at least one finger plate configured to disclosed electrical contact device with blow-off force compensation, according to embodiments of the present disclosure.
[0029] FIG. 4 illustrate exemplary representations of the bottom view disclosed electrical contact device with blow-off force compensation, according to embodiments of the present disclosure.

DETAILED DESCRIPTION
[0030] 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.
[0031] Embodiments explained herein generally relate to electrical contact devices. In particular, the present disclosure relates to an electrical contact device with blow-off compensation through magnetic repulsive force.
[0032] In an aspect of the present disclosure, an electrical contact device with blow-off force compensation, may include an adapter base configured between an adapter pin and a spring at one end of said adapter base and at least one terminal pin at the other end of said adapter base, said adapter base configured allow current to flow between the adapter pin and the at least one terminal pin. Further, the device may also include at least one finger plate configured to allow current to flow between a contact surface indicative of an electric contact of a current carrying device and one of the at least one terminal pin such that direction of flow of current through said at least one finger plate may be opposite to the direction of flow of current flowing through the adapter base to generate a repulsive force that causes the at least one finger plate to repel away from the adapter base and push said at least one finger plates towards the contact surface, thereby compensating the blow-off force from the contact surface and ensuring sustained contact between the contact surface and the at least one finger plate.
[0033] FIG. 1 illustrate exemplary representations of the disclosed electrical contact device 10 with blow-off force compensation. As shown therein, the device 10 includes a contact surface 11, an adapter assembly 21 with an adapter base 211, at least one terminal pin 212 and an adapter pin 213, a spring 29 configured to bias the at least one finger plate 23 to remain in contact with contact surface 11. Further, the device 10 may also include a spring holder 27 and a spring arrester 28 to allow spring 29 to bias more than one finger plates 23 to remain in contact with the contact surface 11. Additionally, the device 10 may also include a pressure disc 24 and a nut plate 25 (shown in FIG. 3) that securely configure the at least one finger plate 23 to the at least one terminal pin 212.
[0034] In an embodiment, the device 10 may include a contact surface 11 configured to be in contact with an adapter assembly 21. In an embodiment, the contact surface 11 indicative of an electrical contact of a current carrying device. The current carrying device may include, but not limited to, a short circuit protection device (SCPD). In an embodiment, the adapter assembly 21 may be an electric contact of a draw-out electric device.
[0035] In an embodiment, the contact surface 11 may be electrically connected to the adapter assembly 21 such that current passes between said contact surface 11 and said adapter assembly 21 through at least one finger plate 23. In an embodiment, the device 10 may also include a spring 29 that ensures a predetermined mechanical force may be applied to on the electric contact of the adapter assembly 21 and the contact surface 11, through the at least one finger plate 23 configured between said contact surface 11 and the adapter assembly 21. By applying a predetermined force, the spring 29 ensures sustained engagement of the contact surface 11 and the adapter assembly 21, through the at least one finger plate 23.
[0036] FIG. 2A and 2B illustrate exemplary representations of the adapter assembly 21 of the disclosed electrical contact device 10 with blow-off force compensation. As shown, the adapter assembly 21 may include an adapter base 211 configured between an adapter pin 213 and at least one terminal pin 212-1 and 212-2 (individually and collectively referred to as terminal pins 212) with corresponding pivot points 22-1 and 22-2 (individually and collectively referred to as pivot points 22).
[0037] In an embodiment, the adapter assembly 21 may include an adapter base 211 configured between at least one terminal pin 213 and an adapter pin 212 such that said adapter base 211 allows current to flow between the adapter pin 213 and the at least one terminal pin 212 through said adapter base 211. The adapter pin 212, the terminal pin 213 and the adapter base 211 may be configured such that current may pass from the at least one terminal pin 213 to the adapter pin 212 through the adapter base 211 in some embodiments, and vice-versa in other embodiments. In an embodiment, the adapter pin 212 and the at least one terminal pin 213 may be configured to the adapter base 211 through processes including, but not limited to, brazing. In one embodiment, the adapter assembly 21 may include only one adapter base 211 configured to one adapter pin 212, while the one or more of the at least one terminal pin 213 may be configured to adapter base 211 is depending on number of parallel branches required for current splitting and other use requirements.
[0038] FIG. 3 illustrate exemplary representations of the at least one finger plate 23 configured to disclosed electrical contact device 10 with blow-off force compensation. As shown, the device 10 may include an at least one finger plate 23-1, 23-2, 23-3 and 23-4 (collectively referred to as finger plate 23). Further, the finger plate 23-1 and 23-2 may be coupled to the terminal pin 212-1, and the finger plate 23-3 and 23-4 may be coupled to the terminal pin 212-2.
[0039] In an embodiment, the at least one finger plate 23 may be rotatably configured to the terminal pin 213. In an embodiment, the terminal pin 213 and the at least one finger plate 23 may include the pivot point 22 indicative of a hole through which a pin, shaft or a projection at one end of said at least one finger plate may be inserted to rotatably configure said at least one finger plate 23 to the terminal pin 213. The pivot point 22 may ensure free rotation of the at least one finger plate 23 with respect to terminal pin 213. In an embodiment, more than one finger plates 23 are rotatably configured to each of the at least one terminal pin 212 in the device 10. Furthermore the at least one finger plate 23 may be configured to allow current to pass between the at least one terminal pin 212 and said at least one finger plate 23. In an embodiment, the number at least one finger plate 23 configured in the device 10 may be determined depending on number of parallel branches required for current splitting and other use requirements.
[0040] FIG. 4 illustrate exemplary representations of the bottom view disclosed electrical contact device 10 with blow-off force compensation. As shown, the device 10 may include a pressure disc 24, a nut plate 25, and a bolt 26 configured to secured the movement of the at least one finger plate 23. Further, the device 10 may also include a spring 29 configured to bias the at least one finger plate 23 by a spring holder 27 and spring arrester 28.
[0041] In an embodiment, the pressure disc 24 and the nut plate 25 may be configured to apply pressure to the pivot point 22 in order to maintain continuity of flow of electric current between the at least one terminal contact surface 23 and the at least one terminal pin 212. In an embodiment, the pressure disc 24 may be in any shape of quadrilateral or circle. In an embodiment, the pressure disc 24 may be configured to a bolt 26 such that on tightening the bolt 26 by applying torque, the pressure disc 24 rotates and compresses the at least one finger plate 23 and the at least one terminal pin 212 between said pressure disc 24 and the nut plate 25. Furthermore, while the pressure disc 24 and the nut plate 25 may ensure adequate contact between the at least one finger plate 23 and the terminal pin 212, the pressure disc 24 may still allow for free rotation of said at least one finger plate 23 post application of torque on the pressure disc 24. In an embodiment, the pressure disc may be any one of a Belleville washer, spring washers, or the like, that allow the at least one finger plate 23 to rotate freely while ensuring adequate contact is maintained between the at least one finger plate 23 and the terminal pin 212. In such embodiments, the at least one terminal contact finger 23 may be rotatably configured to the at least one terminal pin 212 between a pressure disc 24 and a nut plate 25 with the pivot point 22 as an axis of rotation, said pressure disc 24 and said nut plate 25 configured to securely engage the at least one terminal contact finger 23 to the at least one terminal pin 212 while ensuring said at least one terminal contact finger 23 rotates freely.
[0042] In an embodiment, the contact surface 11 may be indicative of an electrical contact of a current carrying device and the at least one finger plate 23 may be indicative of an electrical contact of draw-out device 20. In an embodiment, a spring 29 may be configured to a side on the adapter base 211 that is opposite to the adapter pin 213, said spring 29 configured to bias the at least one finger plate 23 to remain in contact with the contact surface 11 and mechanically compensate blow-off forces. In an embodiment, the spring 29 configured to bias the at least one terminal contact finger 23 via a spring holder 27 configured on a spring holder arrester 28 of each of the at least one terminal contact finger 23. The spring holder may allow the at least one finger plate to securely engage with the spring 29. In an embodiment, the spring holder 27 may be configured between two finger plates 23 connected via a spring arrester 28 coupled to a guiding hole 231 on the at least finger plate 23. The at least one finger plate 23 may be configured such that the force required to rotate said at least one finger plate 23 may be greater than total of forces applied by the pressure discs 24 and total mechanical force applied by the pressure springs 29, when current is not flowing through the device. In an embodiment, the spring 29 may be implemented as a compression spring placed between two of the finger plates 23. In such embodiments, the compression springs can be directly mounted on the at least one finger plate 23. In other embodiments, the spring 29 may be implemented as a torsion spring configured at the terminal pin 212, or leaf spring installed between adapter base 211 and the at least one finger plate 23.
[0043] In an embodiment, the geometric construction of the device 10 may allow for generation of a repulsive force that is in a direction opposite to the blow-off force from the electrical contact, thereby compensating for the blow-off and ensuring sustained contact between the adapter assembly 21 and the contact surface 11. In an embodiment, the adapter base 211 and the at least one finger plate 23 may be configured such that the direction of the flow of current through the adapter base 211 is opposite to the direction of flow of current through each of the at least one finger plate 23. For instance, the direction of flow of current from the adapter pin 213 to the terminal pin 212 through the length of the adapter plate 211 may be opposite to the direction of the current subsequently flowing from the terminal pin 212 to the contact surface 11 through the length of the at least one finger plate 23. In such embodiments, parallel conductors carrying current in opposite directions may generate a repulsive a repulsive force that causes the at least one terminal contact finger (23) to repel away from the adapter base (211) and push said at least one terminal contact fingers (23) towards the contact surface (11), thereby compensating the blow-off force from the contact surface (11) and ensuring sustained contact between the contact surface (11) and the at least one terminal contact finger (23). In an embodiment, the repulsive force may be indicative of a Lorentz force generated that may compensate for blow-off forces developed due to current constrictions, i.e. build-up of electrical pressure due to constriction or restrictions during the flow of current along an electrical system. In some embodiments, blow-off force may develop between contact surface 10 and the at least one finger plate 23. Such blow-off forces may be nullified or compensated for by the Lorentz force, as vector direction of contact the blow-off force may be in a direction opposite to that of repulsive the repulsive force generated in the device 10. Furthermore, given the repulsive force indicative of the Lorentz force is directly proportional to the square of current through parallel current carrying conductor, at higher amplitudes, magnitude of the Lorentz force is also higher, thereby allowing said generated Lorentz force to nullify stronger blow-off forces. Additionally, the magnitude of the repulsive force can be optimized by adjusting factors including, but not limited to, length of at least one finger plate 23, height of adapter base 211, strength of the currents, the distance and the orientation between the at least one finger plates 23 relative to the adapter base 211. In an embodiment, the repulsive forces may be aided by mechanical compensatory forces of the spring 29 to compensate blow-off forces.
[0044] The present disclosure, therefore, solves the need for an electrical contact device with blow-off force compensation. Furthermore, the present disclosure solves the need for an electrical contact device with blow-off force compensation means that is cost effective, is simple to manufacture, and is reliable.
[0045] 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.

ADVANTAGES OF THE INVENTION
[0046] The present disclosure provides a device with blow-off/Holm force compensation through magnetic repulsion between two parallel current carrying conductors.
[0047] The present disclosure provides a device with a reduced length of the current path due to this arrangement.
[0048] The present disclosure provides for sustained contact between the contact surface and the at least one finger plate, even during high amplitude currents, through the generation of a repulsive force that compensates the blow-off force from the contact surface.
[0049] The present disclosure provides for improved safety through the reduction of stress on external compensatory systems.
[0050] The present disclosure provides for cost optimization through the reduction of copper consumption.
[0051] The present disclosure provides a device with a reduced number of electrical joints.
[0052] The present disclosure provides a device with a reduced number of components as compared to conventional jaw contacts.
, Claims:1. An electrical contact device (10) with blow-off force compensation, comprising:
an adapter base (211) configured between an adapter pin (213) at one end of said adapter base (211) and at least one terminal pin (212) at the other end of said adapter base (211), said adapter base (211) configured allow current to flow between the adapter pin (213) and the at least one terminal pin (212); and
at least one finger plate (23) configured to allow current to flow between a contact surface (11) and one of the at least one terminal pin (212) such that direction of flow of current through said at least one finger plate (23) is opposite to the direction of flow of current flowing through the adapter base (211) to a repulsive force that causes the at least one finger plate (23) to repel away from the adapter base (211) and push said at least one finger plates (23) towards the contact surface (11), thereby compensating the blow-off force from the contact surface (11) and ensuring sustained contact between the contact surface (11) and the at least one finger plate (23).
2. The device (10) as claimed in claim 1, wherein more than one finger plates (23) are rotatably configured to each of the at least one terminal pins (212) in the device (10).
3. The device (10) as claimed in claim 1, wherein the at least one finger plate (23) is rotatably configured to the at least one terminal pin (212) between a pressure disc (24) and a nut plate (25) with the pivot point (22) as an axis of rotation, said pressure disc (24) and said nut plate (25) configured to securely engage the at least one finger plate (23) to the at least one terminal pin (212) while ensuring said at least one finger plate (23) rotates freely.
4. The device (10) as claimed in claim 1, wherein the repulsive force generated by flowing current between the at least one finger plate (23) and the adapter base (211) in opposite direction is a Lorentz force generated in a direction that is opposite to the blow-off force from the contact surface (11).
5. The device (10) as claimed in claim 1, wherein magnitude of the repulsive force generated is optimizable by adjusting length of the at least one finger plate (23), height of adapter base (211), strength of the currents, the distance and the orientation between the at least one finger plates (23) relative to the adapter base (211).
6. The device (10) as claimed in claim 1, wherein the device (10) further comprises a spring (29) configured to a side on the adapter base (211) that is opposite to the adapter pin (213), said spring (29) configured to bias the at least one finger plate (23) to remain in contact with the contact surface (11) and mechanically compensate blow-off forces.
7. The device (10) as claimed in claim 6, wherein the spring (29) may be selected from the group comprising compression springs, torsion springs or leaf springs.
8. The device (10) as claimed in claim 6, wherein the spring (29) is configured to bias the at least one finger plate (23) via a spring holder (27) configured on a spring arrester (28) of each of the at least one finger plate (23).