Modular Electrical Switch The present invention relates to an electrical switch used for opening and closing an electrically conductive path between an electric supply and an electric load. In

particular, the present invention relates to an electrical switch based on a modular design.

In conventional electrical switches, a set of movable contacts is displaced relative to a set of stationary contacts to establish or disconnect an electrically

conductive path between supply-side and load-side stationary contacts. The supply-side and load side stationary contacts are connected to an electrical supply and an electrical load respectively. An actuating assembly is provided to cause displacement of the movable contacts from a normal position to an actuated position.

When a movable contact disengages from a corresponding pair of stationary contacts, the electrically conductive path between the electrical supply and the electrical load is disconnected. This position is known as "open position". On the other hand, when the movable contact comes in contact with the corresponding pair of stationary contacts, the electrically conductive path between the electrical supply and the electrical load is established. This position is known as "closed position".

Accordingly, the electrical switches may be classified as normally-open and normally-closed type electrical switches. In case of normally-open electrical switches, the actuating assembly displaces the movable contacts from an open position to a closed position. When an actuating force is removed, various biasing means return the movable contacts back to an open position, and thereby, disconnecting the electrically conductive path. The operation is reversed in case of a normally-closed electrical switch.

In the conventional electrical switches as described above, size of the electrical switch is based on an electrical rating of the electrical switch, that is, magnitude of an operating current and/or an operating voltage that the electrical switch is anticipated to be subjected to during its operation. As the operating current and/or the operating voltage increases, the size of the electrical switch also has to be increased accordingly.

Various constituent elements included in an electrical switch, such as stationary and movable contacts, a carrier assembly, an actuating assembly, a housing structure and so on, have to be proportionately scaled up according to the increase in size of the electrical switch. Thus, a large electrical switch will require huge magnets, huge plastic casing with sufficient mechanical strength to support various constituent elements, and so on.

In the state of the art, specialized large-sized moulding tools and machines are employed to manufacture the huge housing structure required for a large-sized electrical switch. This adversely affects the cost of manufacturing the large-sized electrical switches.

Moreover, various special tools used for manufacturing and assembling metal parts used in smaller electrical switches may not be used for manufacturing and assembling

corresponding metal parts required for large-sized electrical switches as the cost for scaling up is prohibitive. Hence, in accordance with the state of the art, large-sized electrical switches are typically custom-made and manually assembled. This leads to inconsistency and less precision in various mechanical and electrical properties of the large-sized electrical switch, which in turn, leads to less than

satisfactory performance during operation and in extreme cases, to failure of the electrical switch during operation. In light of the foregoing, there is a need to provide an electrical switch design that is suitable for manufacturing electrical switches with high electrical ratings without custom designing and manufacturing various constituent elements .

Accordingly, it is an object of the present invention to provide an electrical switch design that is suitable for manufacturing electrical switches with high electrical ratings without custom designing and manufacturing various constituent elements.

The object of the present invention is achieved by an

electrical switch according to claim 1. Further embodiments of the present invention are addressed in the dependent claims .

In accordance with the aforementioned object, the present invention provides an electrical switch that includes a plurality of electrical switch modules, at least one

actuating assembly, and coupling means for coupling the plurality of electrical switch modules. Each electrical switch module includes a contact assembly and a carrier assembly. The contact assembly includes at least one pair of stationary contacts for connection to an electrical supply and an electrical load and at least one movable contact for establishing an electrical path between the at least one pair of stationary contacts. The at least one movable contact is displaceable relative to the corresponding at least one pair of stationary contacts. The carrier assembly is coupled to the at least one movable contact and configured to displace the at least one movable contact to a first position and a second position relative to the at least one pair of

stationary contacts. The at least one movable contact in the first and the second positions respectively opens and closes an electrically conductive path between the corresponding pair of stationary contacts. The at least one actuating assembly selectively provides an actuating force to effect a displacement of the carrier assembly in at least one of the plurality of electrical switch modules in a first direction resulting in displacement of the at least one movable

contact. The coupling means couple the plurality of

electrical switch modules such that the displacement of each carrier assembly in each of the plurality of electrical switch modules is substantially synchronized, that is, each carrier assembly in the plurality of electrical switch modules moves in the same direction with least relative displacement with respect to any other carrier assembly in the plurality of electrical switch modules such that the at least one movable contact in the plurality of electrical switch modules are displaced to the first and the second positions within such short time window that no adverse electrical phenomenon occurs.

In accordance with an embodiment of the present invention, each electrical switch module is associated with an

individual actuating assembly. The individual actuating assembly is selected from the at least one actuating

assembly. Thus, each electrical switch module includes an actuating assembly for effecting a displacement of the carrier assembly in the first direction. This technical feature ensures that each electrical switch modules generates the actuating force for displacement of the respective carrier assembly. In this embodiment, the coupling means serve only to synchronize the displacement of the carrier assemblies in the plurality of electrical switch modules. In accordance with another embodiment of the present

invention, each electrical switch module includes a housing structure for housing the contact assembly. As each

electrical switch module is provided with an individual housing structure in accordance with this technical feature, this technical feature obviates the need to manufacture a large-sized housing structure to house all the constituent elements of the electrical switch in a single housing and hence, this technical feature advantageously obviates the need to design a specialized moulding structure in accordance with the total size of the electrical switch.

In accordance with another embodiment of the present

invention, the at least one actuating assembly includes an actuating coil configured to create a magnetic field, which provides an actuating force to effect displacement of the carrier assembly in at least one of the plurality of

electrical switch modules in the first direction. This technical feature facilitates using a low-voltage circuit to control an operation of the electrical switch. This low- voltage circuit is electrically isolated from a main circuit, which is opened or closed by the electrical switch. In accordance with still another embodiment of the present invention, the electrical switch further includes a control module configured to regulate the at least one actuating assembly, through regulating a coil current through the actuating coil. The control module is relatively a low- voltage circuit which is electrically isolated from a main circuit, which is electrically opened or closed by the electrical switch. Thus, this technical feature

advantageously facilitates controlling an operation of the electrical switch using a relatively low-voltage circuit. Further, the use of a single control module to regulate the at least one actuating assembly facilitates synchronizing the displacement of carrier assemblies in the electrical switch modules . In accordance with still another embodiment of the present invention, the electrical switch further includes biasing means for effecting a displacement of the carrier assembly in at least one of the plurality of electrical switch modules in a second direction. This technical feature facilitates restoring the movable contacts to a normal position, that is, an open position in a normally-open electrical switch and a closed position in a normally-closed electrical switch subsequent to removal the actuating force provided by the actuating assembly. In accordance with still another embodiment of the present invention, the coupling means couple the carrier assemblies in the plurality of electrical switch modules. This technical feature ensures that the displacement of carrier assemblies in the plurality of electrical switch modules is

substantially synchronized, that is, each carrier assembly in the plurality of electrical switch modules moves in the same direction with least relative displacement with respect to any other carrier assembly in the plurality of electrical switch modules such that the at least one movable contact in the plurality of electrical switch modules are displaced to the first and the second positions within such short time window that no adverse electrical phenomenon occurs.

In accordance with still another embodiment of the present invention, each electrical switch module includes one pair of stationary contacts. This technical feature ensures that single-phase electrical switch modules may be integrated to assemble a multi-phase electrical switch.

In accordance with still another embodiment of the present invention, each electrical switch module includes three pairs of stationary contacts. This technical feature ensures that three-phase electrical switch modules may be integrated to assemble an electrical switch with a desired electrical rating which is higher than the electrical ratings of an individual electrical switch module. Each pair of stationary contacts includes a supply-side stationary contact and a load-side stationary contact. In accordance with yet another embodiment of the present

invention, the electrical switch further includes at least one pair of terminal plates. Each pair of terminal plates includes a first and a second terminal plate. The first terminal plate is coupled to a plurality of supply-side stationary contacts and the second terminal plate is coupled to a corresponding plurality of load-side stationary

contacts. In accordance with this technical feature the terminal plates are directly connected to multiple stationary contacts. According to this technical feature, an

intermediate connecting structure between the stationary contact and the terminal, which is used in the state of the art and which introduces additional electrical resistance in the electrically conductive path between the supply and the load, is rendered unnecessary. Thus, this technical feature prevents deterioration of electrical properties of the electrical switch.

In accordance with yet another embodiment of the present invention, the plurality of supply-side stationary contacts and the corresponding plurality of load-side stationary contacts are selected from at least two ad acently-positioned electrical switch modules. This technical feature ensures that the supply-side stationary contacts and the

corresponding plurality of load-side stationary contacts are most optimally combined to lead to a desired number of terminals for connection to the supply and the load

respectively.

In accordance with yet another embodiment of the present invention, the electrical switch includes a base plate. The plurality of electrical switch modules is mounted on the base plate. This technical feature ensures that the plurality of electrical switch modules, each electrical switch module with its individual housing structure, may be mechanically

integrated to form the electrical switch. In accordance with yet another embodiment of the present invention, the electrical switch includes a top cover for mechanically shielding the plurality of electrical switch modules. This technical feature ensures that various

constituent elements of the electrical switch external to the individual housing structures may be mechanically shielded from the external environment.

The electrical switch in accordance with the present

invention is advantageously based on a modular design such that a desired electrical rating of the electrical switch is achieved through a suitable combination of multiple

electrical switch modules. The individual electrical switch modules may be mass-produced and a suitable number of

electrical switch modules may be combined to achieve a desired electrical rating of the electrical switch. As the individual electrical switch modules may be manufactured using precision tools and machines, accuracy and reliability of these electrical switch modules, and consequently, the resulting electrical switch, is significantly higher as compared to the custom-made electrical switches. Thus, the present invention provides significant reduction in costs for manufacturing electrical switches with high electrical ratings. Thus, the present invention provides an advantageous paradigm shift from custom design to modular design resulting in significantly improved technical and economic feasibility.

Further, the present invention facilitates provision of the actuating assembly corresponding to only a selected set of electrical switch modules included in the electrical switch according to required actuating force for displacing the carrier assemblies in each of the plurality of the electrical switch modules. Due to provision of the actuation assembly in the selected set of electrical switch modules, the overall cost of the electrical switch is further reduced.

Furthermore, various constituent elements, such as connecting rod, base plate, and top cover, required to assemble required for the electrical switch in accordance with the present invention may be manufactured in different sizes based on the desired operating electrical parameters. Alternatively, these constituent elements may also be assembled from smaller units based on a modular design. The present invention is further described hereinafter with reference to illustrated embodiments shown in the

accompanying drawings, in which: FIGS 1A-1D illustrate a set of constituent elements of a three-phase electrical switch module in

accordance with an embodiment of the present invention,

FIGS 2A-2D illustrate a set of constituent elements of a single-phase electrical switch module in

accordance with an alternative embodiment of the present invention,

FIG 3 illustrates a perspective view of an actuating assembly in accordance with an embodiment of the present invention, FIGS 4A-4B illustrate a perspective view and a side view of an electrical switch in accordance with an embodiment of the present invention,

FIG 5 illustrates a front cross-sectional view of an electrical switch in accordance with an

embodiment of the present invention,

FIG 6 illustrates a side cross-sectional view of an electrical switch in accordance with an

embodiment of the present invention, and

FIG 7 illustrates a top cross-sectional view of an

electrical switch in accordance with an

embodiment of the present invention.

Various embodiments are described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident that such embodiments may be practiced without these specific details. FIGS 1A through ID illustrate a set of constituent elements of an three-phase electrical switch module 100 in accordance with the present invention. In particular, FIG 1A illustrates an exploded view of the three-phase electrical switch module 100. The three-phase electrical switch module 100 includes a housing structure 102, a contact assembly 104, a carrier assembly 106, and a mid-cover 108. The housing structure 102 includes two end walls 110, two side walls 112, and three pairs of slots 114. The contact assembly 104 includes three pairs of stationary contacts 116 and corresponding three movable contacts 118. FIGS IB, 1C, and ID illustrate a perspective view, a side view, and an exploded view

respectively of the carrier assembly 106. The carrier

assembly 106 includes three carriers 120. Each carrier 120 includes a mounting socket 122, and a coupling socket 124. The mid-cover 108 includes three slots 126.

The housing structure 102 encloses the contact assembly 104 and a part of the carrier assembly 106. The mid-cover 108 is mounted on top of the housing structure 102 to provide physical and electrical isolation of the space enclosed by the housing structure 102.

The housing structure 102 includes two end walls 110. Each end wall 110 also includes the three pair of slots 114. One or more terminal plates (not shown in the figure) extend inwards through the slots 114 to connect to two or more stationary contacts 116. The two side walls 112 serve to physically partition the electrical switch module 100 from an adjoining electrical switch module 100, while assembling multiple electrical switch modules 100 in accordance with the present invention, as will be explained in conjunction with FIGS 4A and 4B, . As mentioned earlier, the contact assembly 104 includes three pairs of stationary contacts 116 and corresponding three movable contacts 118. Each pair of stationary contacts 116 includes a supply-side stationary contact and a load-side stationary contact. The supply-side and the load-side stationary contacts are

disposed on either side of the carrier assembly 106. The supply-side and the load-side stationary contacts are

connected to the input and output terminal plates, which are, in turn connected to an electrical supply and an electrical load respectively, as will be explained in conjunction with FIGS 4A and 4B, .

Each movable contact 118 is displaceable relative to the corresponding pair of stationary contacts 116 such that when the movable contact 118 is in contact with the pair of stationary contacts 116, an electrically conductive path is established between the electrical supply and the electrical load; and when the movable contact 118 is not in contact with the pair of stationary contacts 116, an electrically

conductive path is disconnected between the electrical supply and the electrical load.

The carrier assembly 106 includes three carriers 120. Each carrier 120 includes the mounting socket 122, and the

coupling socket 124. The carriers 120 extend vertically when assembled in the electrical switch module 100. Each carrier 120 includes the mounting socket 122 to receive and support the movable contact 118. The carrier 120 further includes the coupling socket 124 for engaging a connecting rod (not shown) , such that the carrier assembly 106 may be coupled to an actuating assembly, as will be explained later. The portion of each carrier 120 between the mounting socket 122 and the coupling socket 124 extends outwards from the housing structure 102 through the slot 126 in the mid-cover 108.

The mid-cover 108 is mounted on each electrical switch module 100 to physically isolate the contact assembly 104 enclosed inside the housing structure 102 from the remaining portions of electrical switch 100. The mid-cover 108 includes one or more slots 126 that permit at least a portion of the carrier assembly 106 to extend beyond the housing structure 102. The portion of the carrier assembly 106 that extends beyond the housing structure 102 is used to couple the electrical switch module 100 to the actuating assembly (not shown) . The carrier assembly 106 is configured to displace the movable contacts 118 to a first position and a second

position, relative to the corresponding pair of stationary contacts 116. The first position may be a position in which the movable contact 118 is not in contact with the

corresponding pair of stationary contacts 116, and thus, the electrically conductive path between the pair of stationary contacts 116 is disconnected (open position) . Similarly, the second position may be a position in which the movable contact 118 is in contact with the corresponding pair of stationary contacts 116, and thus, the electrically

conductive path between the pair of stationary contacts 116 is established (closed position) .

As shown, the movable contacts 118, mounted in the mounting sockets 122 of the carrier assembly 106, are in alignment with the pair of stationary contacts 116. Subsequent to application of an actuating force, the carrier assembly 106 undergoes a downward movement and brings the movable contacts 118 in contact with the respective pairs of stationary contacts 116, thereby establishing an electrically conductive path between the two stationary contacts in each pair of stationary contacts 116. When the actuating force is removed, the biasing means, which will be explained in conjunction with FIGS 4A and 4B, will lead to upward movement of the carrier assembly 106 to disconnect the electrically

conductive path between the two stationary contacts in each pair of stationary contacts 116.

During the movement of carrier assembly 106, the slots 126 in the mid-cover 108 facilitate maintaining alignment of the carrier assembly 106, and accordingly of the movable contacts 118, with the stationary contacts 116. FIGS 2A through 2D illustrate a set of constituent elements of a single-phase electrical switch module 200 in accordance with the present invention. In particular, FIG 2A illustrates an exploded view of the single-phase electrical switch module 200. The single-phase electrical switch module 200 includes a housing structure 202, a contact assembly 204, a carrier assembly 206, and a mid-cover 208. The housing structure 202 includes two end walls 210, two side walls 212, and one pair of slots 214. The contact assembly 204 includes one pair of stationary contacts 216 and corresponding one movable contact 218. FIGS 2B, 2C, and 2D illustrate a perspective view, a side view, and an exploded view respectively of the carrier assembly 206. The carrier assembly 206 includes a carrier 220. Each carrier 220 includes a mounting socket 222, and a coupling socket 224. The mid-cover 208 includes a slot 226.

Various elements used in the three-phase electrical switch module 100, as explained in conjunction with FIG 1, are adapted for single-phase electrical switch module 200 to support a single pair of stationary contacts and a single movable contact, as will be readily evident to a person skilled in the art. A detailed explanation is not being provided for sake of brevity. The present invention will hereinafter be described with reference to the three-phase electrical switch module 100. However, various embodiments of the present invention as described hereinafter are equally applicable to the single- phase electrical switch modules 200.

FIG 3 illustrates a perspective view of an actuating assembly 300 in accordance with the present invention.

The actuating assembly 300 includes a stationary sub-assembly and a movable sub-assembly. The stationary sub-assembly includes a base plate 302, a yoke 304, and a bobbin 306. The movable sub-assembly includes a holder 308, an anker 310, and pivot 316. The holder 308 includes pivoting arms 312 and coupling arms 314. The base plate 302 provides a platform to mount the yoke 304. The yoke 304, in turn, provides support to the bobbin 306. Similarly, the holder 308 provides support for the anker 310. The pivoting arms 312 are connected to the pivot 316. The coupling arms 314 provide means to engage the carrier

assembly 106. As mentioned earlier, in an exemplary

embodiment of the present invention, the connecting rod is used to engage the coupling arms 314 with the carrier

assembly 106 through the coupling socket 224. The stationary and the movable sub-assemblies are arranged such that the yoke 304 and anker 310 are assembled in a complementary manner as commonly known in the art. In various embodiments of the present invention, any suitable yoke design may be employed. In the exemplary embodiment shown in FIG 3, the yoke 304 is constructed in form of a three-legged structure using laminated sheets of

ferromagnetic material in accordance with known techniques. On the middle leg of the yoke 304, the bobbin 306 is mounted. Thus, the yoke 304 provides mechanical support for bobbin 306 and also, serves to intensify a magnetic field established by the bobbin 306. The bobbin 306 includes an actuating coil configured to create a magnetic field to provide an actuating force to the carrier assembly 210. The magnetic field is created through application of a coil current. Thus, a magnetic flux is established in the yoke 304. The anker 310 serves to complete a magnetic circuit by providing return path to magnetic flux in the yoke 304.

In absence of a coil current, the movable sub-assembly, in particular, the anker 310 is separated due to the biasing means, which will be explained in conjunction with FIG 4A and 4B, from the stationary sub-assembly, in particular the yoke 304. This position of the movable sub-assembly is referred to as an open position. As the coil current is applied, due to formation of magnetic field through the yoke 304, the anker 310 is magnetically pulled towards the yoke 304, and

consequently, the movable sub-assembly, in particular, the anker 310, moves towards the stationary sub-assembly, in particular the yoke 304, such that the anker 310 comes in contact with the yoke 304. This position of the movable sub ^¬ assembly is referred to as a closed position.

As the carrier assembly 210 is coupled to the movable sub ^¬ assembly through coupling arms 314 and the connecting rod, the movement of the movable sub-assembly causes a

corresponding displacement of the carrier assembly 210 from an open position to a closed position.

It should be noted that the base plate 302 is an optional element. In an alternative embodiment of the present

invention, various constituent elements of the actuating assembly 300, other than the base plate 302, may be directly assembled on the mid-cover 108, in a similar manner. FIGS 4A and 4B, illustrate a perspective view and a side view of an electrical switch 400 in accordance with an embodiment of the present invention. The electrical switch 400 includes two electrical switch modules 100a and 100b, two actuating assemblies 300a and 300b, a connecting rod 402, biasing springs 404, a base plate 406 and a top cover 408. The electrical switch 400 also includes input terminal plates 410, output terminal plates 412, two partition plates 414, and control modules 416a and 416b, individually referred to as control module 416.

The electrical switch 400 provides a means for opening and closing an electrically conductive path between an electrical supply and an electrical load (not shown in the figure) . As explained in conjunction with FIG 1, the three-phase electrical switch module 100 includes a housing structure 102, a contact assembly 104, a carrier assembly 106, and a mid-cover 108. The housing structure 102 encloses the contact assembly 104 and a part of the carrier assembly 106. The mid- cover 108 is mounted on top of the housing structure 102 to provide physical and electrical isolation of various

constituent elements enclosed by the housing structure 102. The actuating assembly 300 is mounted on the mid-cover 108, and coupled to the electrical switch module 100. The

actuating assembly 300 provides an actuating force to effect displacement of the carrier assembly 106 for opening and closing the electrically conductive paths through the

electrical switch 400.

As shown in FIG 4A, the actuating assemblies 300a and 300b are coupled through a connecting rod 402 to electrical switch modules 100a and 100b respectively. In an exemplary

embodiment, the connecting rod 402 spans across the

electrical switch modules 100a and 100b such that the

connecting rod 402 serves not only to couple the actuating assemblies 300a and 300b to electrical switch modules 100a and 100b respectively but also to couple the electrical switch modules 100 such that such that the displacement of each carrier assembly 106 in the electrical switch modules 100a and 100b is substantially synchronized. Thus, the connecting rod 402 provides the coupling means to couple the electrical switch modules 100. In the embodiment of the present invention shown in FIG 4A, the connecting rod 402 couples the carrier assemblies 106 in electrical switch modules 100. In alternative embodiments of the present invention, it is possible to couple other elements such as a movable part of the actuating assembly 300 with the same technical effect. Further, in various alternative embodiments any suitable mechanical structure such as rectangular plates, rods with any suitable cross-section other than a circular cross-section (as depicted in FIG 4A, ) , and so on may be employed for coupling the electrical switch modules 100.

In the embodiment of the present invention, as shown in FIGS 4A and 4B, each electrical switch module 100 is coupled to a corresponding actuating assembly 300. However, in an

alternative embodiment of the present invention, only a selected set of electrical switch modules 100 is provided with corresponding actuating assemblies 300. As the carrier assemblies 106 in remaining electrical switch modules 100 are coupled to the carrier assemblies 106 in the selected set of electrical switch modules 100, the required movement of the carrier assemblies 106 is achieved in all electrical switch modules 100 included in the electrical switch 400.

It should be noted that the actuating assembly 300 has been explained as a separate assembly external to the electrical switch module 100 only for the sake of clarity. In various embodiment of the present invention, as described herein, the actuating assembly 300, when present, may be envisaged to form an integral part of the corresponding electrical switch module 100 in addition to the contact assembly 104 and the carrier assembly 106.

The biasing springs 404 provide the biasing means for

restoring the movable sub-assembly of the actuating assembly 300 and accordingly, the carrier assembly 106 and the movable contacts 118 to a normal position. In case the electrical switch 400 is normally-open, the normal position is an open position. Similarly, in case the electrical switch 400 is normally-closed, the normal position is a closed position. In accordance with the exemplary embodiment of the present invention as shown in FIG 4A, the biasing springs 404 engage the coupling arms 314 of the actuating assembly 300. In various alternative embodiments of the present invention, it is possible to couple the biasing springs 404 with other movable components of the electrical switch 400, such as the carrier assembly 106.

The base plate 406 provides a support for mounting the electrical switch modules 100 in an adjoining manner such that the electrical switch modules 100 are assembled to form the electrical switch 400. In accordance with an embodiment of the present invention, the housing structure 102 includes horizontal and vertical flanges (or walls) with apertures formed therein. The horizontal flanges are used to secure the electrical switch modules 100 to the base plate 406 and the vertical flanges are used to adjoin the electrical switch modules 100a and 100b. The base plate 406 may be manufactured based on a monolithic design or a modular design. In the latter embodiment, each individual base plate corresponds to the size of a single electrical switch module 100, and multiple such base plates are mechanically joined, using for example, nut and bolts or other similar means, to generate a suitably-sized base plate 406.

The top cover 408 extends over the upper portion of

electrical switch 400 and provides a mechanical shield to various constituent elements that are assembled to form the electrical switch 400. The top cover 408 may be manufactured based on a monolithic design or a modular design, similar to the base plate 406, as explained above.

In the exemplary embodiment shown in FIGS 4A and 4B, three input terminal plates 410 are connected to the supply-side stationary contacts and three output terminal plates 412 are connected to the load-side stationary contacts. Each of the terminal plates 410 and 412 is connected to two stationary contacts. Thus, each of the three groups of two adjoining supply-side stationary contacts of electrical switch modules 100 is coupled to an input terminal plate 410. Similarly, each of the three groups of two adjoining load-side

stationary contacts of electrical switch modules 100 is coupled to an output terminal plate 412. During installation of the electrical switch 400, electrical cables are secured to input terminal plates 410 and output terminal plates 412 for establishing an electrical connection to the electrical supply and the electrical load

respectively .

The partition plates 414 are mounted between the input terminal plates 410 and also, between the output terminal plates 412 to provide electrical isolation therein. The control module 416 is configured to regulate the

actuating assemblies 300. The control module 416 is

relatively a low-voltage circuit which is electrically isolated from a main circuit, which is electrically opened or closed by the electrical switch 400. In an exemplary

embodiment, the control module 416 is implemented as a printed circuit board (PCB) . The control module 416

simultaneously triggers the actuating assemblies 300 and thereby, helps to synchronize movement of the carrier

assemblies 106 in the electrical switch modules 100.

During operation of the electrical switch 400, the control module 416 regulates the coil current in the actuating assembly 300. In order to switch on the electrical switch 300, the control module 416 switches on a coil current in the actuating coil of the bobbin 306.

It is imperative to mention that the printed circuit board (PCB) has been mentioned only for exemplary purposes. In various alternative embodiments of the present invention, the control module 416 may be implemented using any suitable component as will be readily apparent to a person ordinarily skilled in the art. Further, it should be noted that in an alternative embodiment of the present invention, multiple control modules 416 may be included. For example, each actuating assembly 300 may be associated with a corresponding control module 416. In case of multiple control modules 416, the operation thereof is synchronized.

Due to the coil current, an actuating force is established. Subsequent to application of the actuating force, the movable sub-assembly of the actuating assembly 300 and hence, the carrier assembly 106 undergo a downward movement, which may be referred to as a first direction. As a result, the movable contacts 118 come in contact with the respective pairs of stationary contacts 116, thereby establishing an electrically conductive path between the two stationary contacts in each pair of stationary contacts 116. Subsequently, in order to switch off the electrical switch 400, the control module 416 switches off the coil current in the actuating coil of the bobbin 306. The biasing springs 404 will cause upward

movement of the movable sub-assembly of the actuating

assembly 300 and hence, the carrier assembly 106. This upward translation movement may be referred as displacement in a second direction. As a result, the electrically conductive path between the two stationary contacts in each pair of stationary contacts 116 is disconnected. Thus, the first and the second direction, as used herein, are opposite to each other, along a rectilinear or a curvilinear path.

During the movement of carrier assembly 106, the slots 126 in the mid-cover 108 facilitate maintaining alignment of the carrier assembly 106, and accordingly the movable contacts 118, with the stationary contacts 116.

In the exemplary embodiment shown in FIGS 4A and 4B, two electrical switch modules 100 have been assembled to form the electrical switch 400. It should be noted that the actual number of electrical switch modules 100 assembled to form electrical switch 400 is dependent on the individual current ratings of electrical switch module 100 and the desired current rating of the electrical switch 400. For example, if each electrical switch modules 100 has an electrical rating of 1000 Amperes, and the desired rating of electrical switch 400 is 4000 Amperes, four electrical switch modules 100 may be assembled to form electrical switch 400.

Further, it should be noted that the number of pairs of stationary contacts, a corresponding number of movable contacts, included in the electrical switch module 100 may be varied as desired. In the exemplary embodiment shown in FIGS 4A and 4B, electrical switch modules 100, each with three pairs of stationary contacts, have been used. It will be appreciated that when two or more such three-phase electrical switch modules 100 are assembled to form an electrical switch 400, the individual 'phases' of the three-phase electrical switch module 100 do not correspond to the three phases of the electrical supply since the individual 'phases' are suitably combined to result in the electrical switch 400 of desired electrical rating. In an alternative embodiment of the present invention, the electrical switch modules 200, each with a single pair of stationary contacts, are used.

As is well-known in the state of the art, the electrical switches are classified as normally-open and normally-closed type electrical switches. It should be noted that the electrical switch 400, as described herein, is a normally- open electrical switch. However, various embodiment of the present invention are equally applicable to normally-closed electrical switch with appropriate modification in the relative positions of the stationary and the movable

contacts, as will be apparent to a person ordinarily skilled in the art .

FIG 5 illustrates a front cross-sectional view of the electrical switch 400 in accordance with the present

invention. The cross-sectional view is along line 1-1' shown in FIG 4A.

As can be seen in the front cross-sectional view, the electrical switch 400 includes two electrical switch modules 100a and 100b, two actuating assemblies 300a and 300b, and a connecting rod 402.

Various constituent elements have already been explained in detail in conjunction with the preceding figures.

FIG 6 illustrates a side cross-sectional view of the

electrical switch 400 in accordance with the present

invention. The cross-sectional view is along line 2-2' shown in FIG 4A.

The side cross-sectional view shows the arrangement of the contact assembly 104, in particular, the pair of stationary contacts 116 and the movable contact 118, and the carrier assembly 106 included in the electrical switch module 100.

FIG 7 illustrates a top cross-sectional view of the

electrical switch 100 in accordance with the present

invention. The cross-sectional view is along line 3-3' shown in FIG 4A.

As shown, the electrical switch module 100a includes supply- side stationary contacts 116a and load-side stationary contacts 116a'. Similarly, the electrical switch module 100b includes supply-side stationary contacts 116b and load-side stationary contacts 116b'. FIG 7 also shows input terminal plates 410a, 410b, and 410c, and output terminal plates 412a, 412b, and 412c.

As can be seen, input terminal plate 410a is connected to two supply-side stationary contacts 116a, input terminal plate 410b is connected to two supply-side stationary contacts 116a and 116b, and input terminal plate 410c is connected to two supply-side stationary contacts 116b. The output terminal plates 412a, 412b, and 412c are coupled to the load-side stationary contacts 116a' and 116b' in a similar manner. As pointed out earlier, the embodiment shown in FIG 4 through FIG 7 is exemplary in nature and any desired number of electrical switch modules 102 may be combined in a similar manner depending on the individual electrical rating of the electrical switch modules 100 or 200 and the desired

electrical rating of the electrical switch 400.

The electrical switch in accordance with the present

invention is advantageously based on a modular design such that a desired electrical rating of the electrical switch is achieved through a suitable combination of multiple

electrical switch modules. The individual electrical switch modules may be mass-produced and a suitable number of

electrical switch modules may be combined to achieve a desired electrical rating of the electrical switch. Thus, the present invention greatly facilitates manufacturing

electrical switches with significantly improved electrical characteristics, and accuracy and reliability of operation. The present invention further facilitates reduction in cost of manufacturing of the electrical switches with high

electrical ratings.

While the present invention has been described in detail with reference to certain embodiments, it should be appreciated that the present invention is not limited to those

embodiments. In view of the present disclosure, many

modifications and variations would present themselves, to those of skill in the art without departing from the scope and spirit of this invention. The scope of the present invention is, therefore, indicated by the following claims rather than by the foregoing description. All changes, modifications, and variations coming within the meaning and range of equivalency of the claims are to be considered within their scope.

List of References

100 Electric Contactor Module

102 Housing Structure

104 Contact assembly

106 Carrier Assembly

108 Mid-Cover

110 End Walls

112 Side Walls

114 Pair of Slots

116 Stationary Contacts

118 Movable Contacts

120 Carrier

122 Mounting Socket

124 Coupling Socket

126 Slots

200 Electric Contactor Module

202 Housing Structure

204 Contact assembly

206 Carrier Assembly

208 Mid-Cover

210 End Walls

212 Side Walls

214 Pair of Slots

216 Stationary Contacts

218 Movable Contacts

220 Carrier

222 Mounting Socket

224 Coupling Socket

226 Slot 300 Actuating Assembly

302 Base Plate

304 Yoke

306 Bobbin

308 Holder

310 Anker

312 Pivoting Arms

314 Coupling Arms

316 Pivot

400 Electrical Contactor

100 Electrical Contactor Module

300 Actuating Assembly

402 Connecting Rod

404 Biasing Springs

406 Base Plate

408 Top-Cover

410 Input Terminal Plate

412 Output Terminal Plates 414 Partition Plate

416 Control Module