The present disclosure relates to the field of ring main unit. More
particularly the present invention relates to a restricted access mechanism for accessing the power switch of the ring main unit.
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] Conventionally, a ring main unit (RMU) is a set of switchgears
used for power distribution. The RMU includes a switch that can be used to
change the operating mode of the RMU. Different operating modes can include an
active mode, OFF mode & Earth mode. In active mode the RMU can be
electrically coupled with input power line, and in the OFF mode, the RMU can be
electrically disconnected from the power input line. The OFF mode can be used at
the time of some servicing and maintenance of the RMU. The RMU carries a very
high voltage in the ON mode and if by any chance some maintenance work is
going on and the RMU is switched back into the ON mode, it can be fatal for a
maintenance who is performing the maintenance and the servicing of the RMU.
[0004] There is, therefore, a need of a safe and secure method of accessing
the RMU for servicing and maintenance work without any possibility of accidental or unintentional changed over of the operating mode (from OFF to ON) of the RMU.
OBJECTS OF THE PRESENT DISCLOSURE
[0005] Some of the objects of the present disclosure, which at least one
embodiment herein satisfies are as listed herein below.
[0006] It is an object of the present disclosure to provide an access
mechanism assembly for a switch in a ring main unit which avoids unintended switching of the switch.

[0007] It is an object of the present disclosure to provide an access
mechanism assembly for a switch in a ring main unit which is cost effective.
[0008] It is an object of the present disclosure to provide an access
mechanism assembly for a switch in a ring main unit which avoids any risk to maintenance person while performing maintenance.
SUMMARY
[0009] The present disclosure relates to the field of ring main unit. More
particularly the present relates to a restricted access mechanism for accessing the power switch of the ring main unit.
[0010] An aspect of the present disclosure pertains to an access
mechanism assembly for a switch in a ring main unit (RMU). The access mechanism includes a shutter plate disposed in front of the switch. The shutter plate includes a cavity disposed corresponding to the switch. A first member, configured to move between a first position and a second position with respect to the cavity, allowing access to one or more controls of the switch. A first switch being configured to move between a third position and a fourth position with respect to the shutter plate. The first switch is operatively coupled with the first member such that the movement of the first switch facilitates the movement of the first member between the first position and the second position. The first switch has a locking mechanism for locking the first switch at any of the third position and the fourth position.
[0011] In an aspect, when the first switch is moved at the third position,
correspondingly the first member may be moved at the first position facilitating access to a first control from the one or more controls of the switch. The first control may comprise switching of the switch between any of a ON position, and an OFF position.
[0012] In an aspect, when the first switch is moved at the fourth position,
correspondingly the first member may be moved at the second position facilitating access to a second control from the one or more controls of the switch. The

second control may comprise switching of the switch between any of the OFF
position, and an earthing position.
[0013] In an aspect, the first switch may comprise a sliding switch
configured to be slide along a guide way, for facilitating movement between the
third position and the fourth position, in the shutter plate.
[0014] 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
[0015] 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.
[0016] 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.
[0017] FIG. 1A illustrates an exemplary representation of an access
mechanism assembly 100 for a switch in a ring main unit (RMU) when the switch
108 is at third position, in accordance with an embodiment of the present
disclosure.
[0018] FIG. IB illustrates an exemplary representation of an access
mechanism assembly 100 for a switch in a ring main unit (RMU) when the switch

108 is at fourth position, in accordance with an embodiment of the present
disclosure.
[0019] FIG. 1C illustrates an exemplary representation of cavity 104 in the
access mechanism assembly, in accordance with an embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0020] 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.
[0021] 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.
[0022] The present disclosure relates to the field of ring main unit. More
particularly the present relates to a restricted access mechanism assembly for accessing the power switch of the ring main unit.
[0023] The present disclosure elaborates upon an access mechanism
assembly for a switch in a ring main unit (RMU). The access mechanism includes a shutter plate disposed in front of the switch. The shutter plate includes a cavity disposed corresponding to the switch. A first member, configured to move between a first position and a second position with respect to the cavity, allowing access to one or more controls of the switch. A first switch being configured to move between a third position and a fourth position with respect to the shutter plate. The first switch is operatively coupled with the first member such that the movement of the first switch facilitates the movement of the first member between the first position and the second position. The first switch has a locking

mechanism for locking the first switch at any of the third position and the fourth
position.
[0024] In an embodiment, when the first switch is moved at the third
position, correspondingly the first member can be moved at the first position for
covering at least first part of the cavity to facilitate access to a first control from
the one or more controls of the switch.
[0025] In an embodiment, the first control can comprise switching of the
switch between any of an ON position, and an OFF position.
[0026] In an embodiment, when the first switch is moved at the fourth
position, correspondingly the first member can be moved at the second position
for covering at least second part of the cavity to facilitate access to a second
control from the one or more controls of the switch.
[0027] In an embodiment, the second control can comprise switching of
the switch between any of the OFF position, and an earthing position.
[0028] In an embodiment, the first switch can comprise a sliding switch
configured to be slide along any or combination of guide way and a guide rail
arrangement, for facilitating movement between the third position and the fourth
position, in the shutter plate.
[0029] FIG. 1A illustrates an exemplary representation of an access
mechanism assembly 100 for a switch in a ring main unit (RMU) when the switch
108 is at third position, in accordance with an embodiment of the present
disclosure.
[0030] FIG. IB illustrates an exemplary representation of an access
mechanism assembly 100 for a switch in a ring main unit (RMU) when the switch
108 is at fourth position, in accordance with an embodiment of the present
disclosure.
[0031] FIG. 1C illustrates an exemplary representation of cavity 104 in the
access mechanism assembly, in accordance with an embodiment of the present
disclosure.
[0032] As illustrated, an access mechanism assembly 100 for a switch in a
ring main unit (RMU) 120. The access mechanism 100 can include a base plate

102 that can be disposed in front of the switch. The base plate 102 can be made of but not limited to a metal. The switch can be referred as operating mode selection switch of the ring main unit 120. Using the switch, the ring main unit can be switched between different operating modes of the ring main unit. The operating modes can include an active mode when the ring main unit is electrically connected to the main power supply line, an OFF mode in which the ring main unit can be disconnected from the main power supply line, and an earthing mode when the ring main unit can be grounded or earthen for earthing any static electric charge on the ring main unit.
[0033] In an embodiment, the base plate 102 can include a cavity 104 that
can be disposed corresponding to the switch. A first member 106 can be
configured to move between a first position and a second position with respect to
the cavity 104. The first member 106 can be made of but not limited to a metal.
The movement of the first member 106 can facilitate or allow access to one or
more controls of the switch. A first switch 108 can be with the first member 106
and can be configured to move between a third position and a fourth position with
respect to the base plate 102. The first switch 108 can be operatively coupled with
the first member 106 such that the movement of the first switch 108, between the
third position and the fourth position, can facilitate the movement of the first
member 106 between the first position and the second position.
[0034] In an embodiment, when the first switch 108 is at the third
position, correspondingly the first member 106 can be moved at the first position to cover at least a first part 104a of the cavity 104, and can facilitate an access to a first control from the one or more controls of the switch. The first control can include switching of the switch between an ON position 112 (also referred as active mode, herein), and an OFF position 114 (also referred as OFF mode, herein). When the first switch 108 is moved at the fourth position, correspondingly the first member 106 can be moved at the second position to cover at least a second part 104b of the cavity 104, and can facilitate access to a second control from the one or more controls of the switch. The second control

can include switching of the switch between the OFF position 114, and an
earthing position 116 (also referred as earthing mode, herein).
[0035] In an embodiment, the first switch 108 can include a sliding switch
that can be configured to be slide along any or combination of guide way 110 and a guide rail arrangement in the base plate 102. Any of the guide ways and the guide rail mechanism can facilitate movement, of the first switch 108, between the third position and the fourth position. The first switch 108 can also be a rotary switch that can be rotated to facilitate movement of the first member 106. The first member 106 can be any of but without limiting to rotatably, and slidably coupled with the first switch 108 such that on switching the position of the first switch 108 between the third position and the fourth position, a corresponding sliding or rotation of the first member 106 takes place. The any of the rotation and sliding of the first member 106 can facilitate its movement between the first position and the second position.
[0036] The switching of the switch, of the ring main unit 120, can be
utilized during various activities such as but without limiting to a maintenance and breakdown scenario of the ring main unit 120. The time such activities, the ring main unit can be switched to the OFF mode and further to avoid any threat from any static charge in the ring main unit 120, the ring main unit can be switched, after switching to the OFF mode, in to the earthing mode. Now, the ring main unit is ready to go under maintenance activity without any threat to the maintenance individual. The shutter plate can include marking which are corresponding to the various operating modes of the ring main unit.
[0037] In an embodiment, the first switch 108 can include a locking
mechanism 118 that can be used for locking the first switch 108 at any of the third position and the fourth position. The locking mechanism 118 can include but without limiting to a pad lock mechanism that can restrict the sliding of the first switch 108 along the guide way 110 in the base plate 102. This can allow any unintended switching of the switch of the ring main unit 120. The first switch 108 can be locked at the fourth position and then after maintenance can be carried out by the maintenance person without any worry of unintentional switching, by

another person, of the switch of the ring main unit back in to the active mode while the maintenance person is doing maintenance work. Also, the first switch 108 can be locked at the third position for avoiding any unintended switching of the ring main unit by any unauthorized person.
[0038] 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.
[0039] 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
[0040] The proposed invention provides an access mechanism assembly
for a switch in a ring main unit which avoids unintended switching of the switch.
[0041] The proposed invention provides an access mechanism assembly
for a switch in a ring main unit which is cost effective.
[0042] The proposed invention provides an access mechanism assembly
for a switch in a ring main unit which avoids any risk to maintenance person while performing maintenance.

We Claim:

1. An access mechanism assembly (100) for a switch in a ring main unit
(120), the access mechanism comprising:
a base plate (102) disposed in front of the switch, the base plate (102) comprising:
a cavity (104) disposed corresponding to the switch;
a first member (106), configured to move between a first position and a second position with respect to the cavity, allowing access to one or more controls of the switch; and
a first switch (108) being configured to move between a third position and a fourth position with respect to the base plate (102), and the first switch (108) is operatively coupled with the first member (106) such that the movement of the first switch (108) facilitates the movement of the first member (106) between the first position and the second position, wherein the first switch (108) has a locking mechanism (118) for locking the first switch (108) at any of the third position and the fourth position.
2. The access mechanism assembly (100) as claimed in claim 1, wherein when the first switch (108) is moved at the third position, correspondingly the first member (106) is moved at the first position, to cover at least a first part of the cavity (104), facilitating access to a first control from the one or more controls of the switch.
3. The access mechanism assembly (100) as claimed in claim 2, wherein the first control comprises switching of the switch between an ON position, and an OFF position.
4. The access mechanism assembly (100) as claimed in claim 1, wherein when the first switch (108) is moved at the fourth position, correspondingly the first member (106) is moved at the second position, to cover at least a second part of the cavity (104), facilitating access to a second control from the one or more controls of the switch.

5. The access mechanism assembly (100) as claimed in claim 4, wherein the second control comprises switching of the switch between the OFF position, and an earthing position.
6. The access mechanism assembly (100) as claimed in claim 1, wherein the first switch (108) comprises a sliding switch configured to be slide along a guide way (110), for facilitating movement between the third position and the fourth position, in the base plate (102).