FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title of the invention. APAD LOCK SAFETY SHUTTER FOR
SWITCHBOARD UNITS

2. Applicant(s)
(a) NAME :
(b) NATIONALITY
(c) ADDRESS :

LARSEN & TOUBRO LIMITED
An Indian Company.
L & T House, Ballard Estate, P.O. .Box: 278 Mumbai 400 001, State of Maharashtra, India

3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed:

TECHNICAL FIELD
[001] The present subject matter described herein, in general, relates to switchboard
units and in particular to an enclosurein switchboard unit for housing equipment and more particularly to a safety shutter that opens and/or covers the enclosure to reduce the risk of inadvertent electrical contact while installing and/or removing equipment from the enclosure.
BACKGROUND
[002] A switchboard unit comprises compartments for accommodating draw-out
type modules, bus bars for carrying high current and electrical connectors that connectmodules to one or more of the bus bars when modules is placed in an enclosure of the compartment. However when the module is withdrawn from the compartment,the bus bars and electrical connectors get exposed due to the opening of the compartment. Therefore it is necessary to cover the conductorswithinthe enclosureof the compartment so that they are not accidentally accessible to operator personnel who may be working within or around a switchboard unit.
[003] Some prior art approaches to protect operating personnel against inadvertent
contact with electrical conductors when an module is drawn out of the compartmentincludes verbal warnings and/or tags attached to the compartment that provides warning to operators against the exposed conductors. This prior approach is not very satisfactory in that it really does not completely inhibit physical contact with exposed bus bars.
[004] Other prior art approaches involves a manual shutter device to cover the
enclosure when the module is drawn out of the compartment so as to restrict exposure of electrical conductors. This shutter is operable by means of in and/out movement of modules within the enclosure so as to cover the live conductors preventing manual access. Due to a manual intervention, the operation of shutter is not completely effective.

[005] In order to overcome the drawback of manual shutter, automatic shutter
mechanism is provided in the art that closes the compartments automatically when a module is drawn out of the compartment without the intervention of an operator personnel and also automatically opensthe compartments when an electrical device is to be inserted back into the compartment to make contacts with bus bars.
[006] The prior art document, US patent number 5,343,355 discloses safety shutter
device for draw-out type switch gear that includes fixed shutter blades and a pair of movable shutter blades provided on the shutter driving units to be actuated by the pushed-in and drawn-out operation of the circuit breaker.
[007] The prior art document, US patent number6,414,839 Bldiscloses shutter
mechanism for vertical bus of motor control center that provides enhanced protection against inadvertent electrical contact for personnel working within and around the electrical enclosure.
[008] However, the hitherto automatic shutter actuation system is tended to be bulky
and complex, and often requires addition space inside the enclosure for mounting the shutter system. Also, in absence of locking mechanism in the shutter system, the shutters will be accessed by unauthorized personnel leading to loss of its functionality.
[009] Thus, in view the drawbacks of the existing shutter mechanism, there exists a
dire need to provide an improved shutter mechanism that enables exposing and/or covering the compartment in correspondence to in and/or out movement of equipment and to further enable locking of the shutter so as to prevent unintended opening of the shutter.
SUMMARY OF THE INVENTION
[0010] The following presents a simplified summary of the invention in order to
provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later. .

[0011] An object of the present invention is to provide animproved shutter
mechanism in switchboard units that allows opening and/or covering a compartment in correspondence to in and/or out movement of a module.
[0012] Another object of the present invention is to provide a shutter mechanism in
switchboard units that is compact in size and simple in construction and operation.
[0013] Yet another object of present invention is to provide a shutter mechanism in
switchboard units that enables locking of a shutter to the compartment when a module is drawn out of the compartment so as to prevent unintended opening of the shutter.
[0014] Accordingly, in one implementation, a switchboard comprising at least one
compartment, having a base frame, for enclosing at least one module configured to be removed/inserted from/in said compartment, at least one shutter slidably connected on said base frame at one end, and other end of said shutter moves along a path between a first position and a second position, a lever element mounted on said base frame, to enable said shutter to move along said path is disclosed. Thelever element includes at least three parts, a hinging point, a pressing point and a stopping point; whereinsaid hinging point is rotatably coupled to said base frame by means of a bracket and configured to displace between an original position and displaced position based on a vertical movement of said pressing point during removal/insertion of said module from/in said compartment; andsaid stopping point is configured to lock/unlock said shutter based on removal/insertion of said module from/in said compartment enabling sliding of said shutter along said path between said first position and said second position.
[0015] In one implementation a lever element to be used in shutter device having a
hinging point, a pressing point and a stopping point is disclosed. The hinging point is coil shaped and is configured to displace between an original position and displaced position based on a vertical movement of said pressing point; andsaid stopping point is configured to lock/unlock at least one shutter based enabling sliding of said shutter along a path between a first position and a second position.

[0016] In one implementation, the present invention provides a shutter mechanism to
protect access to exposed bus bars/conductors in the compartment of the switchboard unit. The mechanism involves a shutter which is operable by means of a lever wherein the lever is configured for receiving a module and thereby enabling the shutter to open and/or close when a module is inserted and/or drawn out of the compartment.In addition to opening and/or closing means of the compartment, the shutter mechanism includes a locking provision that enables locking of the shutter to the compartment when a module is drawn out so as to prevent unintended opening of the shutter.
[0017] Other aspects, advantages, and salient features of the invention will become
apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:
[0018] Figure 1 illustratesa shutter, in accordance with the subject matter of the
present invention
[0019] Figure 2 illustrates an arrangement of a lever and a shutter, in accordance with
the subject matter of the present invention.
[0020] Figure 3 illustrates a construction of a lever that enables the movement of a
shutter, in accordance with the subject matter of the present invention.
[0021] Figure 4 and figure 5 illustrates different views of the lever and its attachment
to a supporting bracket, in accordance with the subject matter of the present invention.

[0022] Figure 6 illustrates the position of a lever, shutter and the module chassis,
when a module is about to be inserted, in accordance with the subject matter of the present invention.
[0023] Figure 7 illustrates the position of a lever, shutter and the module chassis,
when a module is inserted, in accordance with the subject matter of the present invention.
[0024] Figure 8 illustrates the free movement of shutter with respect to chassis
movement, in accordance with the subject matter of the present invention
[0025] Persons skilled in the art will appreciate that elements in the figures are
illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0026] The following description with reference to the accompanying drawings is
provided to assist in a comprehensive understanding of exemplary embodiments of the invention. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary.
[0027] Accordingly, those of ordinary skill in the art will recognize that various
changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
[0028] The terms and words used in the following description and claims are not
limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present

is
invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
[0029] It is to be understood that the singular forms "a," "an," and "the" include
plural referents unless the context clearly dictates otherwise.
[0030] By the term "substantially" it is meant that the recited characteristic,
parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.
[0031] Features that are described and/or illustrated with respect to one embodiment
may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.
[0032] It should be emphasized that the term "comprises/comprising" when used in
this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.
[0033] A person skilled in the art will appreciate that for understanding purpose the
present invention is explained with the help of electrical switchboard units however the disclosed method shall not be considered as the limiting factor for the scope of present invention.
[0034] In one implementation, figure 1 and figure 2 shows position of pad lock lever
and bracket with respect to shutter. The pad lock lever end behinds the shutter preventing its opening. This results in positive locking of shutter when module is kept out of the compartment.
[0035] Referring now to figure 1, in one implementation the shutter (1) enables
opening and/or closing of a compartment by means of a lever (2) in correspondence to in and/or out movement of module within the compartment. The shutter is locked using a

padlock (3) mechanism. In one exemplary embodiment, the shutter used in the present invention is a commonly known shutter or may be any new shutter used in switchboards.
[0036] Referring now to figure 2, in one implementation, the arrangement of alever
(2) and a shutter (1) is shown wherein the arrangement is placed within an enclosure of compartment.
[0037] In one implementation, figure 3, 4 and 5 shows pad lock lever and its
assembly. The pad lock lever has three distinct parts, hinging point as the name suggest allows the lever to rotate so that the spring nature of the lever gets charged which helps it to come back to its original position. A part of the lever is attached to the bracket such that lever acts as a torsion spring when it is pressed down by the module at the pressing point.
[0038] Referring now to figure 3, in one implementation the construction of a lever
(2) includes a hinging point (4) at its one end, a stopping part (6) at its other end, a pressing point (5) intermediately located along its length, and a space for locking mechanism (7). The lever is constructed using an existing material that provides a spring mechanism. In one exemplary embodiment, the length of a lever is 109.7 and the. The space (7) for locking mechanism includes a padlock having a diameter of range between dia 3-dia 6
[0039] Referring now to figure 4 and figure 5, in one implementation hinging point
(4) at one end of a lever (2) is coupled to a base frame of a compartment by means of a supporting bracket (6). The supporting bracket (6) enables the lever (2) to act as a torsion spring when a module is inserted. .
[0040] In one implementation, figure 6 shows position of pad lock lever, shutter and
module chassis when module is started to insert.
[0041] Referring now to figure 6, in one implementation when a module is started to
inserted on a module chassis (8), the shutter (1) open.
[0042] In one implementation, figure 7 shows when module presses the pad lock
lever, shutter can freely rotate with respect to the push movement of module chassis. Similarly when module is drawn out, this particular position is achieved again.

[0043] Referring now to figure 7, in one implementation when a module is made to
press on the pressing point (5) of the lever (2) providing a downward push to the lever (2), the lever (2) rotates so that the spring nature of the lever gets charged. The force on the pressing point (5) enables the lever (2) to move away from their original position so as to enable the shutter (1) to rotate with respect to the push movement of the module chassis (8) on the pressing point (5).
[0044] Referring now to figure 8, in one implementation when a module is further
moved in the compartment the shutter (1) is left free.
[0045] In one implementation, figure 8 shows the free movement of shutter with
respect to chassis movement.
[0046] In one implementation in an event wherein the module is drawn out of the
compartment, the module chassis (8) releases forces on the pressing point (5) while subsequently enabling said lever (2) to return to their original position. The stopping part (6) subsequently couples with the shutter (1) so as to lock further movement of the shutter (1) and thus covering the opening in said compartment.
[0047] Accordingly, in one implementation, a switchboard comprising at least one
compartment, having a base frame, for enclosing at least one module configured to be removed/inserted from/in said compartment, at least one shutter slidably connected on said base frame at one end, and other end of said shutter moves along a path between a first position and a second position, a lever element mounted on said base frame, to enable said shutter to move along said path is disclosed. Thelever element includes at least three parts, a hinging point, a pressing point and a stopping point; whereinsaid hinging point is rotatably coupled to said base frame by means of a bracket and configured to displace between an original position and displaced position based on a vertical movement of said pressing point during removal/insertion of said, module from/in said compartment; andsaid stopping point is configured to lock/unlock said shutter based on removal/insertion of said module from/in said compartment enabling sliding of said shutter along said path between said first position and said second position.

[0048] In one implementation, a lever element to be used in shutter device having a
hinging point, a pressing point and a stopping point is disclosed. The hinging point is coil shaped and is configured to displace between an original position and displaced position based on a vertical movement of said pressing point; andsaid stopping point is configured to lock/unlock at least one shutter based enabling sliding of said shutter along a path between a first position and a second position.
[0049] In one implementation, said first position indicates an open state of said
shutter so as to enable said module to be inserted and second position indicated a closed state of said shutter when said module is drawn out of said compartment.
[0050] In one implementation, said hinging point enables said lever element to rotate
so that a spring nature of said lever element gets charged enabling said lever element to come back to its original position.
[0051] In one implementation, said hinging point attached to said bracket such that
lever element acts as a torsion spring when it is pressed down by the module at said pressing point.
[0052] In one implementation, during said insertion of said module in said
compartment, said pressing point is configured to move down (said vertical movement), thereby enabling said shutter to slide along said path between said first position and said second position, thereby attains said open state to receive said module completely.
[0053] In one implementation, during said removal of said module from said
compartment, said pressing point is configured to move upward (said vertical movement), thereby enabling said shutter to slide along said path between said second position and said first position, thereby attains said close state to remove said module completely and avoiding said open state.
[0054] In one implementation, after said removal of said module from said
compartment, said pressing point is configured to receive at least one physical lock, thereby . restricting said shutter to attain said open state.

[0055] In one implementation, after said removal of said module from said
compartment said lever element is configured to attain said original position thereby restricting said shutter to attain said open state.
[0056] In one implementation, said lever element is configured to end behind said
shutter, preferably, said stopping point ends behind said shutter.
[0057] In one implementation, said lever element is preferably of length 109.7 mm
length, of preferable diameter 1.5 mm, and preferably made of cold drawn spring steel.
[0058] In one implementation, said stopping point is preferably of length 23.1 mm
length in vertical direction.
[0059] Apart from the advantages mentioned above, some of the advantages and
benefits are as mentioned below:
1. The present invention provides a shutter mechanism operable by means of a lever that is simple to construct and compact in size.
2. The lever provided in the present invention enables positive locking of the shutter once module is drawn out of the compartment.
[0060] It may be understood by the person skilled in that art that, the coupling,
joining, fitting of the two components mentioned the present invention may be achieved by any of the existing coupling techniques that may include but not limited to nut and bolt arrangement, gluing, pasting, welding, and the like.
[0061] Although a pad lock safety shutter for switchboardhave been described in
language specific to structural features and/or methods, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific features or methods or devices described. Rather, the specific features are disclosed as examples of implementations of the pad lock safety shutter for switchboard.

WE CLAIM:
1. A switchboard comprising:
at least one compartment, having a base frame, for enclosing at least one module configured to be removed/inserted from/in said compartment;
at least one shutter slidably connected on said base frame at one end, and other end of said shutter moves along a path between a first position and a second position;
a lever element mounted on said base frame, to enable said shutter to move along said path;
said lever element CHARACTERIZED IN THAT it includes at least three parts, a hinging point, a pressing point and a stopping point; wherein
said hinging point is rotatably coupled to said base frame by means of
a bracket and configured to displace between an original position and
displaced position based on a vertical movement of said pressing point during
removal/insertion of said module from/in said compartment; and
said stopping point is configured to lock/unlock said shutter based on
removal/insertion of said module from/in said compartment enabling sliding
of said shutter along said path between said first position and said second
position.
2. The switchboard as claimed in claim 1, wherein said first position indicates an open state of said shutter so as to enable said module to be inserted and second position indicated a closed state of said shutter when said module is drawn out of said compartment.
3. The switchboard as claimed in claim 1, wherein said hinging point enables said lever element to rotate so that a spring nature of said lever element gets charged enabling said lever element to come back to its original position.
4. The switchboard as claimed in claim 1, wherein said hinging point attached to said bracket such that lever element acts as a torsion spring when it is pressed down by the module at said pressing point.

5. The switchboard as claimed in claim 1 and 2, wherein, during said insertion of said module in said compartment, said pressing point is configured to move down (said vertical movement), thereby enabling said shutter to slide along said path between said first position and said second position, thereby attains said open state to receive said module completely.
6. The switchboard as claimed in claim 1 and 2, wherein, during said removal of said module from said compartment, said pressing point is configured to move upward (said vertical movement), thereby enabling said shutter to slide along said path between said second position and said first position, thereby attains said close state to remove said module completely and avoiding said open state.
7. The switchboard as claimed in claim 1 and 2, wherein, after said removal of said module from said compartment, said pressing point is configured to receive at least one physical lock, thereby restricting said shutter to attain said open state.
8. The switchboard as claimed in claim 1 and 2, wherein, after said removal of said module from said compartment said lever element is configured to attain said original position thereby restricting said shutter to attain said open state.
9. The.switchboard as claimed in claim 1, wherein said lever element is configured to end behind said shutter, preferably, said stopping point ends behind said shutter.
10. The switchboard as claimed in claim 1, wherein said lever element is preferably of length 109.7 mm length, of preferable diameter 1.5 mm, and preferably made of cold drawn spring steel.
11. A lever element to be used in shutter device, comprising
a hinging point, a pressing point and a stopping point; wherein
said hinging point is coil shaped and is configured to displace between
an original position and displaced position based on a vertical movement of
said pressing point; and
said stopping point is configured to lock/unlock at least one shutter
based enabling sliding of said shutter along a path between a first position and
a second position.

12. The lever element as claimed in claim 11 is preferably of length 109.7 mm length, of preferable diameter 1.5 mm.
13. The lever element as claimed in claim 11, wherein said stopping point is preferably of length 23.1 mm length in vertical direction.