Claims:1. An interlock for a racking mechanism that mechanically assists movement of a withdrawable type module, said racking mechanism having a racking mechanism lever (4) and said withdrawable type module configured for operation, control and protection of an electrical device connected thereto, wherein the interlock comprising a flexible cable, wherein a first end of the flexible cable is connected to the racking mechanism lever (4), and a second end of the flexible cable is connected to a handle (3) of the withdrawable type module to mechanically assist the movement of said withdrawable type module.

2. The interlock as claimed in claim 1, wherein when the withdrawable type module supplies power to the electrical device, the handle (3), with the flexible cable, pushes a latch (5) of the racking mechanism lever (4) to prevent the movement of said withdrawable type module.

3. The interlock as claimed in claim 2, wherein the latch (5) comprises a racking screw having a hexagonal profile.

4. The interlock as claimed in claim 3, wherein the latch is provided inside a C-shaped component that ensures UP or DOWN vertical movement of the latch, and wherein the latch is provided in such a way that a profile provided on the latch matches with the racking screw with DOWN vertical movement.

5. The interlock as claimed in claim 4, wherein the C-shaped component and the latch are separated by at least one spring, said at least one spring provides a force on the latch in downward direction.

6. The interlock as claimed in claim 3, wherein when the withdrawable type module supplies power to the electrical device, the handle (3), with the flexible cable, pushes the latch to prevent rotation of the racking screw and thereby to prevent mechanically the movement of said withdrawable type module.

7. The interlock as claimed in claim 3, wherein when the withdrawable type module stops supplying power to the electrical device, the handle (3), with the flexible cable, pulls the latch to thereby rotate the racking screw and thereby to allow the movement of said withdrawable type module.

8. The interlock as claimed in claim 1, wherein the flexible cable comprises an inner cable (2) enclosed by an outer cable (1), and wherein a first end of the inner cable (2) is connected to the racking mechanism lever (4) having a latch (5) using a second holder (6”) and a second end of the inner cable (2) is connected to a handle (3) of the withdrawable type module using a first holder (6’).

9. The interlock as claimed in claim 1, wherein withdrawable type module at least comprises a Short Circuit Protecting Device (SCPD), contactors, and relays.

10. A Short Circuit Protecting Device (SCPD) with a racking mechanism that mechanically assists movement of said SCPD, said racking mechanism having a racking mechanism lever (4) and said SCPD configured for operation, control and protection of an electrical device connected thereto, the Short Circuit Protecting Device (SCPD) comprising an interlock having a flexible cable, wherein a first end of the flexible cable is connected to the racking mechanism lever (4), and a second end of the flexible cable is connected to a handle (3) of the withdrawable type module to mechanically assist the movement of said SCPD.
, Description:TECHNICAL FIELD
[0001] The present disclosure relates to switchboards, and more specifically relates to, a short circuit protection device (SCPD) interlock to restrict operation of racking mechanism when circuit is live in panel board feeder.

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] In a panel board, module with SCPD, contactor, relay are provided for operation, control and protection of loads like motor, pumps, conveyors etc. The modules can be withdrawable type. For withdrawing the module, racking mechanism is provided to take module from one position to other. The mechanism can either be open door or closed door type. There are three positions of the module: Isolated, Test and Service. When module is in service position, SCPD (Short Circuit Protecting Device) is switched ON to supply power to the load connected to the module. If one tries to rack-out the module in SCPD ON condition, it can lead to severe arcing since the power contacts will break in live condition. This condition can even be fatal. Thus, it becomes necessary to restrict the racking operation as long as SCPD is in ON condition. Present invention provides the interlocking for racking operation with SCPD ON or OFF condition.
[0004] However, in present product, the racking mechanism can be operated only when the door is opened. When we open the door, the SCPD handle mounted on the door also comes out along with the door. Thus, SCPD cannot be operated till the door is open. When the door is closed and SCPD is switched ON, racking screw is not accessible. Thus, racking operation cannot be performed as long as door is closed. Thus, in case of open door operation, this interlock is not needed. Further, in one of the present product where closed door operation is provided, the interlock is given in such a way that once the SCPD is switched ON, the access to mechanism is blocked. Thus, mechanism for the module cannot be operated as long SCPD is ON. Once SCPD is switched OFF, the access to mechanism is cleared and module can be moved from one position to other. Furthermore, in the conventional product SCPD interlock is provided in closed door module, the access to mechanism is blocked once SCPD is switched ON. But, there is a condition in the same module where if the operating handle is kept inside the module with mechanism shaft, the SCPD can be switched ON and module can be operated and taken from one position to other.
[0005] Whereas there is certainly nothing wrong with existing techniques or system, nonetheless, there still exists a need to provide an efficient, effective, reliable, improved SCPD interlock or interlocking mechanism to restrict operation of racking mechanism when circuit is live in panel board feeder. Further, the proposed invention restricts the operation of racking screw when the SCPD is turned ON. In the proposed invention, SCPD can be turned ON even if the operating handle is kept inserted inside the module. Furthermore, the proposed invention provides cost effective and optimized solution for restricting module movement from one position to other by providing interlock when the SCPD is turned ON. This avoids fatal condition of arcing arising when the contacts are disconnected in live condition.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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.
[00010] 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 groups used in the appended claims.

SUMMARY
[00011] The present disclosure relates to switchboards, and more specifically relates to, a short circuit protection device (SCPD) interlock or interlocking mechanism to restrict operation of racking mechanism when circuit is live in panel board feeder.
[00012] Embodiments of the present disclosure provide an efficient, effective, reliable, improved interlocking mechanism to restrict operation of racking mechanism when circuit is live in panel board feeder.
[00013] Accordingly, an aspect of the present disclosure relates to interlock for a racking mechanism that mechanically assists movement of a withdrawable type module. The racking mechanism can have a racking mechanism lever and withdrawable type module configured for operation, control and protection of an electrical device connected thereto. The interlock can include a flexible cable, wherein a first end of the flexible cable is connected to the racking mechanism lever, and a second end of the flexible cable is connected to a handle of the withdrawable type module to mechanically assist the movement of said withdrawable type module.
[00014] In an aspect, the withdrawable type module can supply power to the electrical device, the handle, with the flexible cable, pushes a latch of the racking mechanism lever to prevent the movement of said withdrawable type module.
[00015] In an aspect, the latch can include a racking screw having a hexagonal profile.
[00016] In an aspect, the latch can be provided inside a C-shaped component that ensures UP or DOWN vertical movement of the latch, and wherein the latch is provided in such a way that a profile provided on the latch matches with the racking screw with DOWN vertical movement.
[00017] In an aspect, the C-shaped component and the latch can be separated by at least one spring, said at least one spring provides a force on the latch in downward direction.
[00018] In an aspect, the withdrawable type module can supply power to the electrical device; the handle with the flexible cable pushes the latch to prevent rotation of the racking screw and thereby to prevent mechanically the movement of said withdrawable type module.
[00019] In an aspect, when the withdrawable type module stops supplying power to the electrical device, the handle with the flexible cable can pull the latch to thereby rotate the racking screw and thereby to allow the movement of said withdrawable type module.
[00020] In an aspect, the flexible cable can include an inner cable enclosed by an outer cable. A first end of the inner cable can be connected to the racking mechanism lever having a latch using a second holder and a second end of the inner cable is connected to a handle (3) of the withdrawable type module using a first holder.
[00021] In an aspect, the withdrawable type module can include a Short Circuit Protecting Device (SCPD), contactors, and relays.
[00022] An aspect of the present disclosure relates to a Short Circuit Protecting Device (SCPD) with a racking mechanism that mechanically assists movement of said SCPD. The racking mechanism can have a racking mechanism lever and the SCPD configured for operation, control and protection of an electrical device connected thereto. The Short Circuit Protecting Device (SCPD) can include an interlock having a flexible cable. A first end of the flexible cable can be connected to the racking mechanism lever, and a second end of the flexible cable can be connected to a handle of the withdrawable type module to mechanically assist the movement of said SCPD.
[00023] In contrast to the conventional interlocking mechanism, the present disclosure discloses objective of the present invention to restrict the operation of racking screw when the SCPD is turned ON. In this case, SCPD can be turned ON even if the operating handle is kept inserted inside the module. Further, in contrast to the existing interlocking mechanism, the present invention provides a lever is attached to SCPD handle through a cable. Thus, when SCPD is turned ON, the lever rotates and takes the latch in downward direction thereby blocking the rotation of racking screw. Furthermore, in contrast to the existing interlocking mechanism, in the present invention operating handle insertion is not restricted when SCPD is turned ON.
[00024] 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
[00025] 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. The diagrams are for illustration only, which thus is not a limitation of the present disclosure, and wherein:
[00026] FIG. 1 illustrates a construction and assembly of SCPD, in accordance with an exemplary embodiment of the present disclosure.
[00027] FIG. 2 illustrates an exemplary working of SCPRD, in accordance with an exemplary embodiment of the present disclosure.
[00028] FIG. 3 illustrates another exemplary working of SCPRD, in accordance with an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION
[00029] 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 scope of the present disclosure as defined by the appended claims.
[00030] If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[00031] 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.
[00032] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. These exemplary embodiments are provided only for illustrative purposes and so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. The invention disclosed may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the scope of the invention. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure). Also, the terminology and phraseology used is for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.
[00033] 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.
[00034] 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.
[00035] 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.
[00036] Problems to be solved in the present invention are that: In present product, the racking mechanism can be operated only when the door is opened. When we open the door, the SCPD handle mounted on the door also comes out along with the door. Thus, SCPD cannot be operated till the door is open. When the door is closed and SCPD is switched ON, racking screw is not accessible. Thus, racking operation cannot be performed as long as door is closed. Thus, in case of open door operation, this interlock is not needed. In conventional product SCPD interlock is provided in closed door module, the access to mechanism is blocked once SCPD is switched ON. But, there is a condition in the same module where if the operating handle is kept inside the module with mechanism shaft, the SCPD can be switched ON and module can be operated and taken from one position to other.
[00037] Therefore there is a need of an efficient, effective, reliable, improved SCPD interlock to restrict operation of racking mechanism when circuit is live in panel board feeder. Further, the proposed invention restricts the operation of racking screw when the SCPD is turned ON. In the proposed invention, SCPD can be turned ON even if the operating handle is kept inserted inside the module. Furthermore, the proposed invention provides cost effective and optimized solution for restricting module movement from one position to other by providing interlock when the SCPD is turned ON. This avoids fatal condition of arcing arising when the contacts are disconnected in live condition.
[00038] The present disclosure relates to switchboards, and more specifically relates to, a short circuit protection device (SCPD) interlock to restrict operation of racking mechanism when circuit is live in panel board feeder.
[00039] The purpose of the invention is to provide cost effective and optimized solution for restricting module movement from one position to other by providing interlock when the SCPD is turned ON. This avoids fatal condition of arcing arising when the contacts are disconnected in live condition.
[00040] Accordingly, an aspect of the present disclosure relates to an interlock or SCPD interlock for a racking mechanism that mechanically assists movement of a withdrawable type module. The racking mechanism can include a racking mechanism lever and the withdrawable type module. The withdrawable type module can be configured for operation, control and protection of an electrical device connected thereto. The interlock can include a flexible cable, wherein a first end of the flexible cable is connected to the racking mechanism lever, and a second end of the flexible cable is connected to a handle of the withdrawable type module to mechanically assist the movement of said withdrawable type module.
[00041] In an embodiment, SCPD devices are integral part of the feeder and their main function is to protect the circuit from undesirably high current flowing in the system. In draw out feeders, there are 3 positions of modules: service, Test and isolation. In isolation position, control and power contacts are disconnected. In test position, only control contacts are connected whereas in service position, control and power contacts are connected. When the module is in service position and SCPD device is turned on, the feeder becomes live. In this position, if a person tries to rack out the module, there is danger of severe arcing when the module is racked out. This condition can be fatal for the person working on the module. Thus, an interlock is provided which will prevent the operation of module from one position to other when SCPD is in ON condition. In this condition, a latch holds the racking screw which has hexagonal profile. There is a flexible specialized nylon wire connecting a lever of the latch to SCPD handle. When SCPD is turned ON, the latch is pushed downward as the lever is pushed by the nylon wire. Once the latch is pushed downwards, it holds the racking screw and thus, the racking screw cannot be rotated as long as latch is holding the screw. Thus, the module cannot be moved from one position to other. When SCPD is turned OFF, the nylon wire can be pulled by the SCPD handle which in turn rotates the lever in opposite direction and latch is lifted up. Thus, the racking screw becomes free to rotate and module can be moved from one position to other.
[00042] For the simplicity of understanding of the subject matter, following reference numerals are used for associated/corresponding feature/elements of the proposed SCPD:
1. outer cable
2. inner cable
3. handle
4. racking mechanism lever
5. latch
6’. first holder
6”. Second holder
[00043] FIG. 1 illustrates a construction and assembly of SCPD, in accordance with an exemplary embodiment of the present disclosure.
[00044] In an embodiment, the location of SCPD can be decided by the layout of the feeder. Thus, X and Y dimension of center of the handle of the SCPD varies for every feeder layout. To have common mechanism for the SCPD interlock, it is necessary to have some flexi link between SCPD handle and the mechanism. A flexi link can be provided in the form of a specialized nylon cable. The nylon cable can have one inner cable 2 and one outer cable 1. The inner cable 2 can be ultrasonically welded with a first holder 6’ at both the ends. The inner cable 2 actually can push/ pull the racking mechanism lever 4 when SCPD is turned OFF/ ON respectively. The first holder 6’ can be connected to SCPD handle through a lever or handle 3 (hereinafter interchangeably referred as “lever”). The second holder 6” can be connected to the racking mechanism lever 4 which in turn is connected to the latch denoted by 5.
[00045] In an exemplary embodiment, the latch 5 can be guided inside a C shaped component which will ensure that the latch has only UP/DOWN vertical movement. The latch 5 can be placed in such a way that the profile provided on the latch matches with the hexagonal racking screw when moved downwards. Two springs can be mounted in between C component and latch. These springs ensure that there is always a positive spring force on the latch in downward direction.
[00046] FIG. 2 illustrates an exemplary working of SCPRD, in accordance with an exemplary embodiment of the present disclosure.
[00047] In an exemplary embodiment, when SCPD is switched ON, the handle 3 on the SCPD handle is shown in FIG.2. It pushes the nylon cable. The racking mechanism lever 4 can rotate and push the latch 5 downwards. Thus, the latch 5 profile gets locked with the hexagonal racking screw. This restricts the rotation of the screw. Thus, module cannot be moved from one location to other when the SCPD is switched ON.
[00048] FIG. 3 illustrates another exemplary working of SCPRD, in accordance with an exemplary embodiment of the present disclosure.
[00049] In an exemplary embodiment, when SCPD is switched OFF, the lever on the SCPD handle is shown in FIG. 3. It pulls the nylon cable. The racking mechanism lever 4 rotates and pulls the latch upwards. Thus, the latch profile relieves the hexagonal racking screw. The screw can be rotated. Thus, module can be moved from one location to other when the SCPD is switched OFF.
[00050] In an embodiment, the proposed mechanism can be adapted for different layouts and SCPDs in feeders by changing the length of the nylon cable. There is a possibility that the edge of racking screw does not align with the edge of latch. In such case, when SCPD is turned ON, the latch remains suspended just above the racking screw. As soon as operator tries to rotate the racking screw, the latch immediately falls down as soon as its edge is aligned with that of the racking screw and thus, it holds the racking screw. This will ensure that the racking screw cannot be rotated further. In case the operator keeps the operating handle inside the module and switches ON the SCPD, the mechanism operates. Thus, it is not possible to rotate the handle and take the module from one position to other. Thus, operator safety is ensured.
[00051] In an embodiment, a lever can be attached to SCPD handle through a cable. Thus, when SCPD is turned ON, the lever rotates and takes the latch in downward direction thereby blocking the rotation of racking screw.
[00052] The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.
[00053] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C ….and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc. The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the appended claims.
[00054] While embodiments of the present disclosure have been illustrated and described, it will be clear that the disclosure is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the scope of the disclosure, as described in the claims.
[00055] In the description of the present specification, reference to the term "one embodiment," "an embodiments", "an example", "an instance", or "some examples" and the description is meant in connection with the embodiment or example described The particular feature, structure, material, or characteristic included in the present invention, at least one embodiment or example. In the present specification, the term of the above schematic representation is not necessarily for the same embodiment or example. Furthermore, the particular features structures, materials, or characteristics described in any one or more embodiments or examples in proper manner. Moreover, those skilled in the art can be described in the specification of different embodiments or examples are joined and combinations thereof.
[00056] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
[00057] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
[00058] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
[00059] 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.