Claims:1. A fail-safe mechanism for a bus coupler (100) and a bus riser (200), the fail-safe mechanism comprising:
a first locking arrangement configured with the bus coupler (100), wherein the first locking arrangement comprises:
a push-button (102), operatively configured with a voltage circuit breaker (VCB) of the bus coupler, and the push-button comprises a distal end (102-1) with a first profile;
a lock plate (104) having a longitudinal slot (104-1) with a second profile (104-2), corresponding to the first profile, at a first end of the longitudinal slot, and the push button being slidably configured with the lock plate, wherein the distal end facilitates after the push-button is pushed, switching the VCB between an electrically closed position and an electrically open position through the second profile (104-2); and
a key adapted to be removably configured with a first cavity (106) in a fascia (108) of the bus coupler (100), the key being configured to rotate between a first position and a second position to enable movement of the lock plate (104), wherein a rotation of the key to the first position aligns the distal end (102-1) and the second profile (104-2) such that the distal end (102-1) is allowed to slide, to operate the VCB, through the second profile (104-2) of the longitudinal slot.
2. The fail-safe mechanism as claimed in claim 1, wherein a maximum width of the distal end (102-1) is less than a minimum width of the second profile (104-2) so that the distal end (102-1) is allowed to slide, when aligned with the second profile (104-2), through the second profile (104-2).

3. The fail-safe mechanism as claimed in claim 1, wherein a minimum width of the distal end (102-1) is greater than the maximum width of the longitudinal slot (104) such that the distal end (102-1) is restricted to slide through the longitudinal slot (104) when the distal end (102-1) and the second profile (104-2) are misaligned.
4. The fail-safe mechanism as claimed in claim 3, wherein rotation of the key to the second position misaligns the distal end (102-1) and the second profile (104-2) such that the sliding movement of the push-button (102) through the second profile (104-2) is restricted and the switching of the VCB is prevented.
5. The fail-safe mechanism as claimed in claim 1, wherein the key is configured to be removed, from the first cavity (106) when the key is at the second position such that after removing the key, the sliding movement of the push button (102) through the second profile (104-2) is restricted.
6. The fail-safe mechanism as claimed in claim 1, wherein the fail-safe mechanism comprises a second lock arrangement configured with the bus riser (200), the second lock arrangement comprising:
a shutter plate (202) configured to move between a third position and a fourth position, wherein the shutter plate (202) at the third position covers a disconnector access hole (204) and at the fourth position uncovers the disconnector access hole (204); and
a second cavity (206) in a fascia (208) of the bus riser (200), wherein the key is adapted to be removably configured with the second cavity (206), and the key, after inserting in the second cavity (206), is configured to rotate between a fifth position and a sixth position, wherein rotation of the key to the sixth position facilitates movement of the shutter plate (202) to the fourth position for facilitating access, through the disconnector access hole (204), to the disconnector of the bus riser (200).
7. The fail-safe mechanism as claimed in claim 6, wherein while operating the disconnector, through the disconnector access hole (204), the push-button (102) is restricted from pushing as the distal end (102-1) and the second profile (104-2) are misaligned.
8. The fail-safe mechanism as claimed in claim 6, wherein rotation of the key to the fifth position facilitates movement of the shutter plate (202) to the third position for covering the disconnector access hole (204).
9. The fail-safe mechanism as claimed in claim 8, wherein the key is configured to be removed from the second cavity when the key is at the fifth position.
, Description:TECHNICAL FIELD
[0001] The present disclosure relates to the field of gas-insulated switchgear. More particularly the present disclosure relates to a fail-safe mechanism for bus coupler and bus riser used for electrically connecting inputs of gas-insulated switchgear with each other.

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] A typical gas-insulated switchgear (GIS) board includes an incomer & multiple outgoing panels. In a case when the incomer panel is in a faulted condition or under maintenance, there will be no supply for the outgoing panels and outgoing loads. Hence, to avoid this system downtime, one board of GIS is electrically coupled with another GIS board using Bus Coupler & Riser. FIG. 1 shows a conventional signal line diagram for GID. When both the incomers I/C1 & I/C2 of the two GIS boards are functioning, the disconnector of the bus coupler and the bus riser will be in the electrically open position, and I/C 1 will supply power to O/G 1, 2, 3 of the first board and I/C 2 will supply to O/G 4, 5, 6 of the second board. But if I/C1 is faulted or under maintenance, then first board A and second board B can be electrically coupled together using the bus coupler and the bus riser. For this, the voltage circuit breaker (VCB) of the bus coupler needs to be in an electrically open condition, then the disconnector of the bus coupler and the bus riser is turned to an electrically closed condition, and then the VCB of the bus coupler can again be turned to the electrically closed condition.
[0004] If the disconnector is turned to an electrically ON condition while the VCB is still electrically closed then there can be arching and flashing at the disconnector contacts which is undesirable and can damage the system sometimes. Also, it is prohibited to turn the VCB to the electrically on condition while the disconnector of the bus riser is not turned to electrically on condition completely. However, there are chances that someone can still operate the disconnector accidentally or unintentionally while the VCB is electrically ON or, operate the VCB of the bus coupler while the disconnector of the bus riser is not completely electrically ON.
[0005] There is, therefore, a need for a fail-safe system for the bus coupler and the bus riser without compromising the above-discussed requirements.

OBJECTS OF THE PRESENT DISCLOSURE
[0006] Some of the objects of the present disclosure, which at least one embodiment herein satisfies are as listed herein below.
[0007] It is an object of the present disclosure to provide a fail-safe mechanism for coupling a bus coupler and a bus riser, which avoids any possibility of operating a disconnector of the bus riser when the VCB of the bus coupler is electrically ON.
[0008] It is an object of the present disclosure to provide a fail-safe mechanism for coupling a bus coupler and a bus riser, which avoids any possibility of turning electrically ON the VCB of the bus coupler while operating the disconnector of the bus riser.
[0009] It is an object of the present disclosure to provide a fail-safe mechanism for coupling a bus coupler and a bus riser, which is easy to operate.
[0010] It is an object of the present disclosure to provide a fail-safe mechanism for coupling a bus coupler and a bus riser, which prevents any arching condition while operating the disconnector of the bus riser.
[0011] It is an object of the present disclosure to provide a fail-safe mechanism for coupling a bus coupler and a bus riser, which is cost-effective.

SUMMARY
[0012] The present disclosure relates to the field of gas-insulated switchgear. More particularly the present disclosure relates to a fail-safe mechanism for bus coupler and bus riser used for electrically connecting inputs of gas-insulated switchgears with each other.
[0013] An aspect of the present disclosure pertains to a fail-safe mechanism for a bus coupler and a bus riser. The fail-safe mechanism includes a first locking arrangement configured with the bus coupler. The first locking arrangement includes a push-button, operatively configured with a voltage circuit breaker (VCB) of the bus coupler, and the push button has a distal end with a first profile. A lock plate has a longitudinal slot with a second profile, corresponding to the first profile, at a first end of the longitudinal slot. The push-button is slidably configured with the lock plate, such that the distal end facilitates after the push-button is pushed, switching the VCB between an electrically closed position and an electrically open position, on through the second profile. A key adapted to be removably configured with a first cavity in a fascia of the bus coupler. The key is configured to rotate between a first position and a second position to enable movement of the lock plate. Rotation of the key to the first position aligns the distal end and the second profile such that the distal end is allowed to slide, to switch the VCB, through the second profile of the longitudinal slot.
[0014] In an aspect, a maximum width of the distal end may be less than a minimum width of the second profile so that the distal end is allowed to slide, when aligned with the second profile, through the second profile.
[0015] In an aspect, a minimum width of the distal end may be greater than the maximum width of the longitudinal slot such that the distal end is restricted to slide through the longitudinal slot when the distal end and the second profile are misaligned.
[0016] In an aspect, rotating of the key to the second position may misalign the distal end and the second profile such that the sliding movement of the push-button through the second profile is restricted and the switching of the VCB is restricted.
[0017] In an aspect, the key may be configured to be removed, from the first cavity when the key is at the second position such that after removing the key, the sliding movement of the push button through the second profile is kept restricted.
[0018] In an aspect, the fail-safe mechanism may comprise a second lock arrangement configured with the bus riser. The second lock arrangement includes a shutter plate configured to be moved between a third position and a fourth position. The shutter plate at the third position covers a disconnector access hole and the shutter plate at the fourth position uncovers the disconnector access hole. A second cavity in a fascia of the bus riser, and the key is adapted to be removably configured with the second cavity. The key, after inserting in the second cavity, is configured to rotate between a fifth position and a sixth position. Rotating the key to the sixth position facilitates movement of the shutter plate to the fourth position for facilitating access, through the disconnector access hole, to the disconnector of the bus riser.
[0019] In an aspect, while operating the disconnector, through the disconnector access hole, the push-button may be restricted from pushing as the distal end and the second profile are misaligned.
[0020] In an aspect, rotating the key to the fifth position may facilitate movement of the shutter plate to the third position for covering the disconnector access hole.
[0021] In an aspect, the key may be configured to be removed from the second cavity when the key is at the fifth position.
[0022] 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 DRAWINGS
[0023] 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.
[0024] In the figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.
[0025] FIG. 1A illustrates an exemplary representation of a conventional signal line diagram for gas-insulated switchgear, in accordance with an embodiment of the present disclosure.
[0026] FIG. 1B illustrates an exemplary representation of a front view of the bus coupler, in accordance with an embodiment of the present disclosure.
[0027] FIG. 2A illustrates an exemplary representation of a rear view of the bus coupler when the key is at the second position, in accordance with an embodiment of the present disclosure.
[0028] FIG. 2B illustrates an exemplary representation of a rear view of the bus coupler when the key is at the first position, in accordance with an embodiment of the present disclosure.
[0029] FIG. 3 illustrates an exemplary representation of a front view of the bus riser, in accordance with an embodiment of the present disclosure.
[0030] FIG. 4A illustrates an exemplary representation of a rear view of the bus riser when the key is at the fifth position, in accordance with an embodiment of the present disclosure.
[0031] FIG. 4B illustrates an exemplary representation of a rear view of the bus riser fascia when the key is at the sixth position, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0032] 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.
[0033] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.
[0034] The present disclosure relates to the field of gas-insulated switchgear. More particularly the present disclosure relates to a fail-safe mechanism for bus coupler and bus riser used for electrically connecting inputs of gas-insulated switchgears with each other.
[0035] The present disclosure elaborates upon a fail-safe mechanism for a bus coupler and a bus riser. The fail-safe mechanism includes a first locking arrangement configured with the bus coupler. The first locking arrangement includes a push-button, operatively configured with a voltage circuit breaker (VCB) of the bus coupler, and the push button has a distal end with a first profile. A lock plate has a longitudinal slot with a second profile, corresponding to the first profile, at a first end of the longitudinal slot. The push-button is slidably configured with the lock plate, such that the distal end facilitates after the push-button is pushed, switching the VCB between an electrically closed position and an electrically open position, on through the second profile. A key adapted to be removably configured with a first cavity in a fascia of the bus coupler. The key is configured to rotate between a first position and a second position to enable movement of the lock plate. Rotation of the key to the first position aligns the distal end and the second profile such that the distal end is allowed to slide, to switch the VCB, through the second profile of the longitudinal slot.
[0036] In an embodiment, a maximum width of the distal end can be less than a minimum width of the second profile so that the distal end is allowed to slide, when aligned with the second profile, through the second profile.
[0037] In an embodiment, a minimum width of the distal end can be greater than the maximum width of the longitudinal slot such that the distal end is restricted to slide through the longitudinal slot when the distal end and the second profile are misaligned.
[0038] In an embodiment, rotating of the key to the second position can misalign the distal end and the second profile such that the sliding movement of the push-button through the second profile is restricted and the switching of the VCB is restricted.
[0039] In an embodiment, the key can be configured to be removed, from the first cavity when the key is at the second position such that after removing the key, the sliding movement of the push button through the second profile is kept restricted.
[0040] In an embodiment, the fail-safe mechanism can comprise a second lock arrangement configured with the bus riser. The second lock arrangement includes a shutter plate configured to be moved between a third position and a fourth position. The shutter plate at the third position covers a disconnector access hole and the shutter plate at the fourth position uncovers the disconnector access hole. A second cavity in a fascia of the bus riser, and the key is adapted to be removably configured with the second cavity. The key, after inserting in the second cavity, is configured to rotate between a fifth position and a sixth position. Rotating the key to the sixth position facilitates movement of the shutter plate to the fourth position for facilitating access, through the disconnector access hole, to the disconnector of the bus riser.
[0041] In an embodiment, while operating the disconnector, through the disconnector access hole, the push-button can be restricted from pushing as the distal end and the second profile are misaligned.
[0042] In an embodiment, rotating the key to the fifth position can facilitate movement of the shutter plate to the third position for covering the disconnector access hole.
[0043] In an embodiment, the key can be configured to be removed from the second cavity when the key is at the fifth position.
[0044] FIG. 1B illustrates an exemplary representation of a front view of the bus coupler, in accordance with an embodiment of the present disclosure.
[0045] FIG. 2A illustrates an exemplary representation of a rear view of the bus coupler when the key is at the second position, in accordance with an embodiment of the present disclosure.
[0046] FIG. 2B illustrates an exemplary representation of a rear view of the bus coupler when the key is at the first position, in accordance with an embodiment of the present disclosure.
[0047] As illustrated, a fail-safe mechanism for coupling a bus coupler 100 and a bus riser 200 can include a first locking arrangement that can be configured with the bus coupler 100. The first locking arrangement can include a push-button 102 that can be operatively configured with a voltage circuit breaker 108 of the bus coupler 100. The push-button has a distal end 102-1 with a first profile. The first profile can correspond to a shape of the distal end of the push-button. A lock plate 104 can be configured with the push-button 102. The lock plate 104 can have a longitudinal slot 104-1 with a second profile, corresponding to the first profile, at a first end of the longitudinal slot 104. The second profile 104-2 can correspond to a shape of the longitudinal slot 104-1 such that the distal end can slide through the longitudinal slot 104-1 through the second profile (104-2) only.
[0048] In an embodiment, the push-button 104 can be slidably configured with the lock plate in a direction perpendicular to a longitudinal axis of the lock plate 104. The distal end 102-1 can facilitate, after the push-button 104 is pushed, switching the VCB between an electrically closed position and an electrically open position, on sliding through the second profile. A key can be adapted to be removably configured with a first cavity 106 in a fascia of the bus coupler. The key can be configured to rotate, after inserting in the first cavity 106, between a first position and a second position for enabling movement of the lock plate 104. Rotation of the key to the first position may align the distal end 102-1 and the second profile of the longitudinal slot 104-1 such that the distal end 102-1 is allowed to slide, to operate the VCB, through the second profile 104-2 of the longitudinal slot 104.
[0049] In an embodiment, the maximum width of the distal end 102-1 can be less than the minimum width of the second profile 104-2 of the longitudinal slot 104, so that, the distal end 102-1 is allowed to slide, only when aligned with the second profile, through the second profile. Minimum width of the distal end 102-1 can be greater than the maximum width of the longitudinal slot 104 such that the distal end 102-1 can be restricted to slide through the longitudinal slot 104 when the distal end 102-1 and the second profile are misaligned. Rotating the key to the second position can misalign the distal end 102-1 and the second profile such that the sliding movement of the push-button through the second profile 104-2 is restricted and the switching of the VCB is restricted. In this way, switching of the VCB can be done only when the key is at the first position. The key can be configured to be removed, from the first cavity 106 only when the key is at the second position such that after removing the key, the sliding movement of the push button through the second profile is kept restricted till the key is again inserted in the first cavity 106 and is rotated to the second position.
[0050] FIG. 3 illustrates an exemplary representation of a front view of the bus riser, in accordance with an embodiment of the present disclosure.
[0051] FIG. 4A illustrates an exemplary representation of a rear view of the bus riser when the key is at the fifth position, in accordance with an embodiment of the present disclosure.
[0052] FIG. 4B illustrates an exemplary representation of a rear view of the bus riser fascia when the key is at the sixth position, in accordance with an embodiment of the present disclosure.
[0053] In an embodiment, the fail-safe mechanism can include a second lock arrangement configured with the bus riser 200. The second lock arrangement can include a shutter plate 202 that can be configured to be moved between a third position and a fourth position. The shutter plate 202 at the third position can cover a disconnector access hole 204 and the shutter plate 202 at the fourth position uncovers the disconnector access hole 204. The disconnector access hole 204 can correspond to a hole in the fascia of the bus rise through which the disconnector 210 can be accessed for operation. The disconnector can be accessed through the disconnector access hole 204 when the bus coupler and the bus riser need to be electrically coupled together.
[0054] In an embodiment, the bus riser 200 can include a second cavity 206 in a fascia of the bus riser 200. The key can be adapted to be removably configured with the second cavity 206. The key, after inserting in the second cavity 206, can be configured to rotate between a fifth position and a sixth position. Rotating the key to the sixth position can facilitate movement of the shutter plate 202 to the fourth position for facilitating access, through the disconnector access hole, to the disconnector of the bus riser. While operating the disconnector, through the disconnector access hole 204, the push-button 102 can be restricted from pushing as the distal end and the second profile are misaligned since the key is taken out of the first cavity 106. Thus, the push-button 102 cannot be pushed as the sliding movement of the distal end through the second profile 104-2 is restricted due to misalignment of the distal end 102-1 and the second profile. Rotating the key to the fifth position can facilitate movement of the shutter plate 202 to the third position for covering the disconnector access hole 204 such that no operation can be performed on the disconnector of the bus riser when the key is at the fifth position. The key can be removed from the second cavity 206 when the key is at the fifth position.
[0055] The present disclosure pertains to a fail-safe mechanism that can be used in the case when the bus coupler 100 and the bus riser 200 need to be electrically coupled. For this, the key needs to be taken out of the first cavity after rotating it to the second position turning the VCB of the bus coupler 100 to electrically OFF condition. Further, the key can be inserted in the second cavity 206 of the bus riser 200 and rotated to the sixth position for uncovering the disconnector access hole 204 for turning the disconnector of the bus riser to electrically ON condition. At the same time, the VCB is restricted from getting electrically turned ON since the distal end sliding movement of the push-button is restricted as the distal end and the second profile are misaligned. This avoids any possibility of turning ON the disconnector of the bus riser when the VCB of the bus coupler is electrically ON. Also, any possibility of turning electrically ON of the VCB of the bus coupler 200 at the time of operating the disconnector of the bus riser 200 is avoided.
[0056] Moreover, in interpreting the specification, 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 refer 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.
[0057] 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
[0058] The proposed invention provides a fail-safe mechanism for coupling a bus coupler and a bus riser, which avoids any possibility of operating a disconnector of the bus riser when the VCB of the bus coupler is electrically ON.
[0059] The proposed invention provides a fail-safe mechanism for coupling a bus coupler and a bus riser, which avoids any possibility of turning electrically ON the VCB of the bus coupler while operating the disconnector of the bus riser.
[0060] The proposed invention provides a fail-safe mechanism for coupling a bus coupler and a bus riser, which is easy to operate.
[0061] The proposed invention provides a fail-safe mechanism for coupling a bus coupler and a bus riser, which prevents any arching condition while operating the disconnector of the bus riser.
[0062] The proposed invention provides a fail-safe mechanism for coupling a bus coupler and a bus riser, which is cost-effective.