Claims:1. A top frame for switchboard enclosure, the top frame comprising:
a pair of front member and rear member having plurality of vertical C shape structures, wherein the vertical C- shape structures are configured for detachable engagement with plurality of vertical pillars of the switchboard enclosure;
a pair of left side member and right side member; and
at least one cross member configured between the front member and the rear member;
wherein the left side member, right side members and the at least one cross member are detachably attached to the front member and the rear member to enable their removal without affecting the front member, rear member and the plurality of vertical pillars of the switchboard enclosure.
2. The top frame of claim 1, wherein the left side member and the right side member are detachably attached to the front member and the rear member through corner link plates that are fixed at two ends of each of the front member and the rear member.
3. The top frame of claim 2, wherein the left side and the right side members incorporate common link plates at their two ends for detachable engagement with the corner link plates of the front member and the rear member by means of threaded fasteners.
4. The top frame of claim 3, wherein the at least one cross member also incorporates common link plates at its two ends for detachable engagement with common link plates fixed at desired locations on the front member and the rear member.
5. The top frame of claim 3, wherein the corner link plates incorporate projections that get located in corresponding cut-outs in the front member and the rear member.
6. The top frame of claim 5, wherein the front member and the rear member incorporate an extended profile at both their ends where the corner link plates are fitted, wherein the extended profile locates and supports the corner link plate through the cut-outs.
7. The top frame of claim 6, wherein the extended profile further provides adequate lower surface on the front member and the rear member for fixing vertical “C” shape structure.
8. The top frame of claim 6, wherein the corner link plate further incorporates a bent profile that compensates the distance due to the extended profile and butts against upper surface of the front member and the rear member to provide more support and strength.
9. The top frame of claim 3, wherein the common link plate incorporates projections both on top and bottom sides that get located in corresponding cut-outs in the front member or the rear member or the side member.
10. The top frame of claim 9, wherein position of the projections on the common link plate and accordingly of the cut-outs on the front member and the rear member on the two sides is different to avoid wrong fitment. , Description:TECHNICAL FIELD
[0001] The present disclosure relates generally to the field of low voltage power distribution and control systems. In particular, the present disclosure relates to skeleton for switchboards in which top frame assembly can be dismantled for busbar/fishplate replacement.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Two types of switchboards are used to distribute low voltage electric power: Power Control Centre (PCC) and Motor Control Centre (MCC). A Power Control Centre distributes the power to different Motor Control Centre and the Motor Control Centres distribute that power intelligently to different loads such as motor loads and lamp loads using feeders/modules. Both these switchboards incorporate various power distribution, control and protection assemblies housed within a metallic enclosure. These metal enclosures incorporate a skeleton which is an essential and important part as it carries load of the various power distribution assemblies housed in the switchboard.
[0004] The skeleton/shell of the switchboard enclosure typically comprises of a top frame and a bottom frame connected through pillar like vertical members to form a generally rectangular three dimensional structure. The bottom and top frame assemblies themselves have number of channels connected to each other which is generally done by welding. The frame and the pillar like vertical members are also generally joined permanently by welding. However dismantling of skeleton/shell assembly especially top frame assembly can provide access for easy maintenance of switchboard/panel. In case of flashover, busbar or fishplate of busbar joints should be easily accessible for replacement and which is only possible if the top frame assembly is detachable.
[0005] Prior art literature United States patent number 5228762A discloses one such metal frame constructed from sections of the same structural element. This structural element is obtained by folding a metal strip. The sections of the structural element are cut to the required dimensions to defineuprights, longitudinal members and cross-members which are welded together at their ends to form a metal frame/ skeleton for metal cabinet.
[0006] European Patent number 0472793 (A1) discloses a cabinet frame structure for housing electrical and electronic equipment that is formed from flanged, hollow, square-section members and comprising a vertical member and two horizontal members meeting at a corner. Each member is formed by bending of metal sheet (alternatively by extrusion) to have four walls and one or two flanges extending generally in the same plane as the walls. At the corner the flanges of the members are mitred and the flanges are cut short to enable the three members to fit together and be welded to form a rigid corner structure.
[0007] United States patent number 3919603A discloses a three-phase metal-enclosed switchgear unit or assembly that incorporates a single piece or unitary corner tie for supporting three structural members in a mutually perpendicular relationship. Each corner tie is constructed with three mutually perpendicular leg portions. Each leg portion comprises a generally rectangular member having a longitudinally extending open portion the edges of the open portion extending into outward facing flanges. Structural members can slide onto the corner tie to be held in a mutually perpendicular alignment. Slotted openings are provided in the flanged portions of the corner tie through which multiple openings in the structural members are readily accessible for rigidly securing the corner tie to the perpendicularly disposed structural members.
[0008] As can be seen, of the above three prior art patent references only the United States patent number 3919603A discloses a metal-enclosed switchgear unit or assembly that incorporates feature of joining the horizontal and vertical members by threaded fasteners through the corner tie by means of the slotted openings provided in the flanged portions of the corner tie through which multiple openings in the structural members are readily accessible for rigidly securing the corner tie to the perpendicularly disposed structural members. However, the disclosed arrangement involves use of a corner tie for each of the corners of the shell. The corner tie is an additional item and involves separate manufacturing and attended costs. Besides above, in view of inherent design of the corner tie, members of the top frame cannot be removed individually and complete top frame sub assembly has to be separated from the vertical members/pillars and thereafter dismantled if required. As can be appreciated, removal of top frame as an assembly can be troublesome exercise due to size and weight. It would be advantageous if each member of the top frame could be removed individually to make the process less tedious.
[0009] There is therefore a need in the art for an alternate method of assembling the shell of the electric switchboards using threaded fasteners that enables dismantling of the top frame by removal of individual members.
[0010] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0011] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0012] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0013] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0014] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

OBJECTS OF THE INVENTION
[0015] A general object of the present disclosure is to provide a skeleton/shell for electrical switchboards in which top frame can be dismantled for ease of maintenance.
[0016] An object of the present disclosure is to provide a skeleton/shell for electrical switchboards with removable top that overcomes shortcomings of the known prior art.
[0017] Yet another object of the present disclosure is to provide a skeleton/shell that uses common-link plates for joining the members/ channels.
[0018] Still another object of the present disclosure is to provide a skeleton/shell that provides fast joining of members/ channels

SUMMARY
[0019] Aspects of the present disclosure relate to shell or skeleton for electrical switchboard enclosures. In particular, the disclosure provides a shell for switchboard enclosures in which top frame can be dismantled for ease of maintenance or modifications, wherein the disclosed shell does not require any additional parts such as a corner tie to join different members of the shell.
[0020] In an aspect, the shell can comprise a top frame, a bottom frame and plurality of vertical members (also referred to as channels and the two terms used interchangeably hereinafter) connecting the top and the bottom frames. The top frame and the bottom frames can themselves comprise plurality of members (or channels) such as front member, rear member, side members for left side and right side, and one or more cross-members linking the front and rear members.
[0021] In an aspect, the members of the top frame incorporate link plates that are welded to each of the members in appropriate positions so that all top frame members among themselves can be connected to each other by bolting thorough link plates. There can be two types of link plates: first one (corner link plate) can be configured for connecting the side members to the front and the rear members providing corner joints and can be fixed to ends of the front and rear members. The second can be configured for providing ‘T’ joints between the cross-members and the front and the rear members. In an aspect, the second link plate can be used at multiple places i.e. on both ends of the side members for joining with the corner link plate, both ends of the cross-members and also on the front and rear members or joining with cross-members to provide a ‘T’ joint; and the second link plate is accordingly termed as common link plate. In an aspect, the arrangement of the common link plate at multiple places reduces variety of components with attended cost benefits.
[0022] In an aspect, all members of the top frame can be bolted together to get a top frame sub assembly. The corner and common link plates can be permanently fixed to the respective members at their respective places by any suitable process such as welding to reduce number of items. The link plates, both corner link plates and the common link plates, can incorporate holes that match each other when the respective members are placed in assembly position to facilitate assembly by threaded fasteners. Additionally, there can be weld nuts fixed on the link plates for ease of and hastening the assembly process.
[0023] In an aspect, assembly of vertical pillars with top frame assembly can be achieved by a ‘C’ shaped structure which is fixed to front and rear channels at appropriate places. The ‘C’ shaped structure can be fixed to front and rear channels at appropriate places by welding, and can incorporate holes and weld nuts to enable fixing of the vertical pillars/members by threaded fasteners through corresponding holes in the vertical pillars/members at their ends. In an aspect, the corner link plates and the ‘C’ shaped structure are designed such that they do not affect joining of vertical pillar with the top frame and do not hinder removal of the top frame assembly as one unit in case so desired.
[0024] In an aspect, assembling the members of the shell by bolting can enable their dismantling as and when required for maintenance and modifications such as replacement of busbar or fish plate of panel. Further, the top frame can be removed as an assembly or its constituent members can be removed individually depending on their size and weight at convenience of the user.
[0025] In an aspect, the switch board enclosure shell of the present disclosure can be shipped in dismantled condition and assembled at site thus requiring less space during storage and transportation bringing in corresponding cost benefits.
[0026] 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
[0027] 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.
[0028] FIG. 1 illustrates an exemplary perspective view of top frame assembly in accordance with an embodiment of the present disclosure.
[0029] FIG. 2 illustrates an exemplary part exploded view of the top frame assembly in accordance with an embodiment of the present disclosure.
[0030] FIG. 3 illustrates an exemplary perspective view showing assembly of a set of corner link plate to front/rear member and common link plate to a side channel of the top frame assembly in accordance with an embodiment of the present disclosure.
[0031] FIG. 4 illustrates an exemplary detailed view of corner link plate in accordance with an embodiment of the present disclosure.
[0032] FIG. 5A and 5B illustrate exemplary perspective views showing assembly of common link plates to front/rear member and to a cross-member along with details of the common link plate in accordance with an embodiment of the present disclosure.
[0033] FIG. 6 illustrates an exemplary detailed view of assembly of top frame and vertical pillars in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0034] 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.
[0035] 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.
[0036] 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.
[0037] Aspects of the present disclosure relate to shell or skeleton for electrical switchboard enclosures. In particular, the disclosure provides a top frame that can be dismantled from the shell. The shell can comprise a top frame, a bottom frame and plurality of vertical members/channels connecting the top and the bottom frames. The constituent members of the top frame such as side members for left side and right side, and one or more cross-members linking the front and rear members can be individually dismantled and thereafter the front and rear members can be separated from the vertical pillar members.
[0038] In an aspect, the members of the top frame incorporate link plates that are welded to each of the members in appropriate positions so that all top frame members among themselves can be connected to each other by bolting thorough link plates. There can be two types of link plates: first one (corner link plate) can be configured for connecting the side members to the front and the rear members providing corner joints and can be fixed to ends of the front and rear members. The second can be configured for providing ‘T’ joints between the cross-members and the front and the rear members. In an aspect, the second link plate can be used at multiple places i.e. on both ends of the side members for joining with the corner link plate, both ends of the cross-members and also on the front and rear members or joining with cross-members to provide a ‘T’ joint; and the second link plate is accordingly termed as common link plate. In an aspect, the arrangement of the common link plate at multiple places reduces variety of components with attended cost benefits.
[0039] In an aspect, all members of the top frame can be bolted together to get a top frame sub assembly. The corner and common link plates can be permanently fixed to the respective members at their respective places by any suitable process such as welding to reduce number of items. The link plates, both corner link plates and the common link plates, can incorporate holes that match each other when the respective members are placed in assembly position to facilitate assembly by threaded fasteners. Additionally, there can be weld nuts fixed on the link plates to for ease of and hastening the assembly process.
[0040] In an aspect, assembly of vertical pillars with top frame assembly can be achieved by a ‘C’ shaped structure which is fixed to front and rear channels at appropriate places. The ‘C’ shaped structure can be fixed to front and rear channels at appropriate places by welding, and can incorporate holes and weld nuts to enable fixing of the vertical pillars/members by threaded fasteners through corresponding holes in the vertical pillars/members at their ends. In an aspect, the corner link plates and the ‘C’ shaped structure are designed such that they do not affect joining of vertical pillar with the top frame and do not hinder removal of the top frame assembly as one unit in case so desired.
[0041] In an aspect, assembling the members of the shell by bolting can enable their dismantling as and when required for maintenance and modifications such as replacement of busbar or fish plate of panel. Further, the top frame can be removed as an assembly or its constituent members can be removed individually depending on their size and weight at convenience of the user.
[0042] In an aspect, the switch board enclosure shell of the present disclosure can be shipped in dismantled condition and assembled at site thus requiring less space during storage and transportation bringing in corresponding cost benefits.
[0043] Referring now to FIG. 1 wherein an exemplary top frame assembly 100 in accordance with various embodiments of the present disclosure is disclosed. As shown the top frame assembly 100 can include a number of members/channels such as two side channels 102 and 104 connected with front channel 106 and rear channel 108. There can additionally be a middle/cross channel 110 to provide support to front and rear channels 106 and 108. All these members/channels being part of the top frame 100are horizontally placed. By joining these members/channels complete top frame assembly 100 can be completed which can thereafter be fixed to vertical pillar (not shown here) at corners. Assembly of the vertical pillar with the top frame assembly can be done through vertical C- shape structures 112 which can be fixed to front channel 106 and rear channel 108 at appropriate places as per the requirement of complete shell assembly.
[0044] FIG. 2 illustrates an exemplary exploded view 200 of the top frame assembly 100 in accordance with an embodiment of the present disclosure. As shown all the members/channels can incorporate link plates permanently fixed by suitable process such as welding at appropriate locations to facilitate their assembly using threaded fasteners. There can be two types of link plates: first one - corner link plate 204 /206 can be configured for connecting the side members 102/104 to the front and the rear members 106/108 by providing corner joints. The corner link plate 204 /206 can be fixed to ends of the front member 106 and the rear member 108. In an aspect the two corner link plates 204 and 206 fixed at opposite ends of a member – front or rear - can be mirror image of each other.
[0045] In an embodiment, the second of the link plates – common link plate 202 - can be configured for providing ‘T’ joints between the cross-members 110 and the front and the rear members 106/108. In an aspect, the second link plate can also be used at both ends of the side members 102/104, as shown in FIG. 2, for joining with the corner link plates 204/206. Thus the common link plate can be fixed permanently by welding to both ends of the cross-members such as 110 and side members 102/104. In addition, the common link plate 202 plate can also be used on the front and rear members 106/108 for joining with cross-member 110 to provide a ‘T’ joint. In an aspect, the arrangement of the common link plate 202 at multiple places reduces variety of components with attended cost benefits.
[0046] FIG. 3 illustrates an exemplary perspective view 300 showing assembly of the corner link plate 206 and common link plate 202 to front member 106 and the side channel 102 respectively in accordance with an embodiment of the present disclosure. As shown, both the link plates can incorporate holes to facilitate their joining by threaded fasteners such as nuts and bolts. The nuts can be welded to one of the link plates to ease assembly process.
[0047] FIG. 4 illustrates an exemplary detailed view 400 of corner link plates 206 in accordance with an embodiment of the present disclosure. In an aspect, the corner plate 204 and 206 can be configured with features that enable its fixing on the respective members 106/108 of the top frame 100. For example, thecorner link plate 206can incorporate three projections such as 402 and 404 which can get located in corresponding cut-outs such as 406 and 408 in the respective member such as front member 106. After proper location of the corner plate 206 on the front member 106 the two can be welded to make the corner link plate 206 a fixed part of front member 106. In same manner all the corner link plates 204/206 can be fitted on all ends of the front and rear members 106/108 of the top frame 100.
[0048] In an embodiment, the front and rear members 106/108 can incorporate an extended profile 410 at both their ends where the corner link plates 204/206 are to be fitted. Besides providing support and locating the corner link plate 204/206 through cut-outs 408, the extended profile 410 can also provide adequate lower surface on the front/rear members 106/108 for fixing vertical “C” shape structure 112 (not shown here). The extended profile 410 can also help in accommodating lifting bolts 412 at location in the front/rear member 106/108.
[0049] In an embodiment, the corner link plates 204/206 can incorporate an additional feature of bent profile 412 that compensating the distance due to the extended profile 410 can butt against upper surface of front/rear members 106/108 to provide more support and strength when joined by welding.
[0050] In an embodiment, suitable nuts can be welded to the inner surface 414 of the corner link plate 204/206 which incorporates holes for threaded fasteners. The nuts can be aligned with the holes for the bolts to pass through the holes and engage with the nuts.
[0051] FIG. 5A and 5B illustrate exemplary perspective view 500 and 550 respectively showing assembly of common link plates 202 to front/rear member 206/208 and to a cross-member 110 along with details of the common link plate 202 in accordance with an embodiment of the present disclosure. As shown therein the front/rear members 106/108 and the cross-member 110 can incorporate the common link plates 202 in respective positions. The common link plate 202 can incorporate projections 504 both in top and bottom sides and these projections 504 can get located in corresponding cut-outs in the front member 106 (or the rear member 108 as the case may be). The positioning of these projections (and accordingly the cut-outs on the front/rear members 106/108) on the two sides can be different to avoid wrong fitment.
[0052] In an embodiment, like in case on the corner link plates 204/206, the common-link plates 202 can also be welded with nuts in alignment of holes thereon to help faster assembly process. The same concept is used for connection of channels on other side.
[0053] FIG. 6 illustrates an exemplary detailed view 600 of assembly of top frame and vertical pillars in accordance with an embodiment of the present disclosure. As shown the cross members 110 and side members 102/104 of the top frame can be dismantled to facilitate replacement of the busbars or fish plates in the event of flashover or for any other any maintenance work. As can be seen, the cross members 110 and the side members 102/104 can be detached without affecting others members such as front/rear members 106/108 of the top frame 100 and the vertical pillar 602. Further, if required the top frame 100 can also be detached as an assembly by disconnecting the pillars 602 from the vertical C- shape structures 112. Since the top frame 100 is detachable, it can be assembled anywhere at site or factory. The members of the top frame 100 can be dismantled and packed/stored in a small space which can bring in resultant cost benefits.
[0054] 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
[0055] The present disclosure provides a skeleton/shell for electrical switchboards in which top frame can be dismantled for ease of maintenance.
[0056] The present disclosure provides a skeleton/shell for electrical switchboards with removable top that overcomes shortcomings of the known prior art.
[0057] The present disclosure provides a skeleton/shell that uses common-link plates for joining the members/ channels.
[0058] The present disclosure provides a skeleton/shell that provides fast joining of members/ channels.