Claims:WE CLAIM:

1. An automatic shutter arrangement for covering plug-in hole in plug-in feeder busway (1), said arrangement comprising:
a top housing of busway (11) and main conductors (12) inside plug- in feeder busway (1);
a plug-in unit (2) comprising an enclosure (21) adapted to assemble a set of jaws (22) for operatively engaging with said conductors (12) inside said plug-in feeder busway (1) and an automatic shutter actuator (23) on both sides of the said enclosure (21) for actuation of slider plates (32 and 33);
a plug in hole assembly (3) comprising a plug in hole base cover (35), a plug in feeder hole (37) configured to receive said jaws (22) of said plug-in unit (2), a plug in hole top cover (31), a compression spring (34) with loaded slider plates (32 and 33);
wherein said slider plates (32 and 33) are placed one upon each other and are configured to move opposite to each other for blocking said plug in feeder hole (37) and said compression springs (34) is placed between said plates (32 and 33) for pushing plates away from each other.
2. An arrangement as claimed in claim 1 wherein said slider plates (32 and 33) are mounted on said plug in hole base cover (35) of the plug in hole assembly (3).
3. An arrangement as claimed in claim 1 wherein said automatic shutter actuator (23) is configured to push said slider plates (32 and 33) and opens said plug in feeder hole (37) configured to receive said jaws (22) of said plug-in unit (2) and allows said feeder hole (37) to close only after jaws (22) are out of the plug in feeder holes (37).
4. An arrangement as claimed in claim 1 wherein said slider plate (32) is adapted to block half of the width of the plug in feeder hole (37) and said slider plate (33) is adapted to cover another half of the said plug in feeder hole (37).
5. An arrangement as claimed in claim 1 wherein movement of the said slider plates (32 and 33) are limited due to the features on said plug in hole base cover (35).

6. An arrangement as claimed in claim 1 wherein said slider plates (32 and 33) are adapted to manage the close pitch of two different phases in horizontal axis.
7. An arrangement as claimed in claim 1 wherein said plug in feeder hole (37) is covered with an additional top cover.

Dated this 29th day of March 2019

Abhishek Sen
IN/PA Reg No: 980
Of S. MAJUMDAR & CO.
(Applicant’s Agent)
, Description:F O R M 2

THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)

1. Title of the invention –

AN AUTOMATIC SHUTTER AT PLUG-IN POINT LOCATION OF BUSBAR TRUNKUNG SYSTEMS

2. Applicant(s)

(a) NAME : LARSEN & TOUBRO LIMITED

(b) NATIONALITY: An Indian Company.

(c) ADDRESS: 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
The present invention generally relates to a busway. In particular, the invention relates to automatic shutters for covering plug-in point location on busways.
BACKGROUND AND PRIOR ART
Busways are installed in residential, commercial as well as industrial premises for the distribution purpose. Plug-in units are installed in the busways for the final distribution. During installation of plug in units into plug in feeder the top cover is manually opened. Upon opening the live conductors are exposed and users may come in contact with live parts leading to injury/death of an individual. In order to avoid any external access except jaws of Plug in units these holes need to be closed and should be accessible only to the jaws of plug in units. The plug-in Feeder is one of the key accessories of busways. Plug-in units are installed on plug-in feeder to tap off the power from the main conductors. Currently plug-in hole location is covered with an additional top cover when it is not in use. So manual operation for removal of plug-in hole top cover is always involved. Post removal of top covers live conductors are exposed and may be accessible to human finger. In order to avoid direct contact of live parts these Plug in hole should be hidden with shutters until Plug in unit is inserted into it.

The document US7517235B2 discloses press fit connection for mounting electrical plug-in outlet insulator to a busway aluminum housing with a molded plastic outlet box for electric busway systems comprising: a molded plastic base comprising a plurality of press-fit tabs for attachment of the base to a housing of the electric busway system disposed about a bottom surface of the base. Document US2902555A discloses a shutter control for the bus duct plug-in unit and document US2888529A discloses interlock means for bus duct plug-in units.
The above mentioned documents discloses shutters which offers protection only for series arranged (vertical axis) plugin holes and not placed parallel (horizontal axis). Also, existing shutter does not offer solution to close pitch to each other in horizontal axis. Existing prior arts uses only one slider moving in a particular direction to provide access for jaws to enter in and focuses on the automatic shutter operation while insertion of Plug-in unit. Prior arts focus on safety with respect to operating personnel in the surrounding, as bus duct is charged.

Thus, in view of the above mentioned drawbacks, to avoid direct contact of live parts these plug in hole should be hidden with more reliable shutters until plug in unit is inserted into it.

OBJECT OF THE INVENTION
An object of the present invention is to provide spring loaded sliding plates to resolve space constraint issue.
An object of the present invention is to provide profile of automatic shutter actuator such that it pushes slider plates appropriately and opens for jaw insertion and allows slider plates to close only after jaws are out of plug in holes.
Another object of the present invention is to provide 2 Slider plates placed one upon each other and reduction in stroke required to be moved by each slider plate by 50%.
Another object of the present invention is to provide safety to the user handling the system.
Yet another object of the invention is use of spring force between two moving components rather than on one fixed and thereby reducing complexity of the mechanism.
Yet another object of the invention is to provide protection for both series arranged vertical axis plug in the holes as well as a horizontal axis plug in holes.
These and other advantages of the present invention will become readily apparent from the following detailed description read in conjunction with the accompanying drawings.

SUMMARY OF THE INVENTION
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.
In accordance with the purposes of the present invention in one aspect there is embodied and broadly described an arrangement of automatic shutters for covering of plug-in hole in plug-in feeder busway for ensuring safety of the user.
In one implementation, the invention uses a compression spring with loaded slider plates and the slider plates are placed one upon each other and are configured to move opposite to each other.
In one implementation, the invention uses compression springs which are placed between the plates and are configured for pushing plates away from each other.
In another implementation, the invention uses a plug-in unit which comprises an enclosure adapted to assemble a set of jaws for engaging with the conductors inside the plug-in feeder busway.
In another implementation, the enclosure of the plug in unit of the invention comprises automatic shutter actuators on both sides of the enclosure for actuation of the slider plates.
Yet in another implementation, the invention uses a plug in hole assembly which comprises of a plug in hole base, a plug in the feeder hole configured to receive the jaws of the plug-in unit and a plug in hole top cover.
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
It is appreciated that the drawings provided in the present disclosure only illustrate application examples of the present disclosure and are therefore not to be construed as limiting its scope. The foregoing disclosure provides additional information with additional specificity and detail with the accompanying drawings, which are listed below for quick reference.
Figure 1 illustrates the isometric view of the plug in feeder unit with automatic shutters (sliders) closed, in accordance with an embodiment of the present disclosure.
Figure 2 illustrates the isometric view of plug in feeder unit with automatic shutters (sliders) open, in accordance with an embodiment of the present disclosure.
Figure 3 illustrates the isometric view of plug in unit with plug in feeder before insertion, in accordance with an embodiment of the present disclosure.
Figure 4 illustrates the isometric view of plug in unit entering into plug in hole assembly, in accordance with an embodiment of the present disclosure.
Figure 5 illustrates the isometric view of plug in feeder with plug in hole assembly and automatic shutters (sliders), in accordance with an embodiment of the present disclosure.
Figure 6 (a) and 6 (b) illustrates the isometric view of automatic shutters (sliders) in plug in hole closed and in open state respectively, in accordance with an embodiment of the present disclosure.
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 INVENTION
It should be understood at the outset that although illustrative implementations of the present disclosure are illustrated below, the present invention may be implemented using any number of techniques, whether currently known or in existence. The present disclosure should be in no way limited to illustrative implementations, drawings, and techniques, illustrated below, including the exemplary design and implementation illustrated and described herein, but may be modified within the scope of equivalents.
Unless otherwise defined, all terms and especially technical and/or scientific terms, used herein, may be taken to have the same meaning as commonly understood by one having an ordinarily skilled in the art.
Reference is made herein to some “embodiments”. It should be understood that an embodiment is an example of a possible implementation of any features and/or elements presented in the foregoing claims. Some embodiments have been described for the purpose of illuminating one or more potential ways in which the specific features and/or elements of the foregoing claims fulfill the requirements of uniqueness, utility, and non-obviousness.
The invention is an arrangement of automatic shutter at plug-in point location on plug-in feeder busways. While inserting plug-in unit, shutter will be operated due to the arrangement in said invention and provides safety during insertion and removal of plug in units from plug in feeders. Automatic shutter should be completely opened before actual contact jaw insertion commences. Similarly, once plug-in unit is removed it should come to closed condition. To achieve the same, this arrangement consists of spring loaded slider plates with actuators from Plug-in units, at plug-in hole location. The disclosed invention consists of sliding plates, one upon another and move opposite to each other when plug in unit is inserted and allows access to jaws to enter in to plug in holes. This plugs the plug in feeder hole and does not allow access to live conductors. Thus, said invention provides safety with its universal mechanism.
In one implementation, the invention discloses an arrangement of automatic shutters for covering of plug-in hole (37) in plug-in feeder busway (1) for ensuring safety of the user and uses a compression spring (34) with loaded slider plates (32 and 33) and the slider plates are placed one upon each other and are configured to move opposite to each other.
In one implementation, the invention provides safety to human by not allowing live part kept exposed. Plug in feeder (1) has provisions of holes (37) for Jaws (22) of plug in units (2) to enter main conductors (12). Currently plug-in hole (37) locations are covered with an additional top cover when it is not in use. So manual operation for removal of plug-in hole top cover is always involved.
In one implementation of the invention, in order to avoid direct contact of live parts plug in hole (37) are hidden with shutters until plug in unit (2) is inserted into it as post removal of top cover live conductors (12) are exposed and may be accessible to human finger.
In another implementation, the present invention discloses an arrangement which consists of springs (34) loaded slider plates (32 and 33) mounted on plug in hole base cover (35). (Refer Figure 6). The slider plates (32 & 33) are placed one upon another and compression spring (34) is mounted between these two plates at 2 locations. The spring always pushes the slider plates (32 and 33) away from each other and the movement of the sliders is limited because of features on plug in hole base cover (35). This arrangement is covered with a plug in hole top cover (31).
In another implementation, Plug in units (2) has an enclosure (21) over which jaws (22) and automatic shutter actuator (23) are assembled.
Yet in one implementation of the invention, during insertion of plug in unit (2) into plug in feeder (1) the automatic shutter actuator (23) touches the slider plates (32 and 33) on both sides and pushes the plates inside. There by creating holes for jaws (22) of plug in unit (2) can enter and engage with conductors (12). (Refer Figure 4) During this operation the compression springs 34 are loaded and energy is stored within.
Yet in one more implementation of the invention, when plug in unit (2) is removed out of plug in feeder busway (1) the slider plates (32 and 33) remains in open position until the jaws (22) are completely out of plug in holes (37) and this is achieved through the profile of automatic shutter actuator (23). Once the plug in unit (2) is completely pulled out the energy stored in the spring (34) is released, causing the slider plates (32 and 33) to come to closed position and there by closing the access to conductors (12).
The need of two slider plates (32 and 33) upon each other is to manage the close pitch of two different phases along horizontal axis. One slider plate (32) blocks half of the width of Plug in feeder hole (37) and other half is blocked by another slider plate (33) placed below it when plug in unit (2) is not inserted. This helps in reducing the stroke required to be moved by each slider plate (32 and 33) by 50%.

Some of the benefits of the present invention, considered to be noteworthy are mentioned below:

1. With spring loaded sliding plates space constraint issue is resolved.

2. Profile of automatic shutter actuator such that it pushes slider plates appropriately and opens for jaw insertion and allows slider plates to close only after jaws are out of plug in holes.

3. 2 Slider plates placed one upon each other and reduction in stroke required to be moved by each slider plate by 50%.

4. Use of a spring force between two moving components rather than on one fixed and thereby reducing complexity of the mechanism.