FORM2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title of the invention: NO LOAD SWITCHING APPARATUS WITH A RACKING MECHANISM FOR THREE POSITION DISCONNECTION
2. Applicant(s):

(a) NAME : LARSEN & TOUBRO LIMITED
(b) NATIONALITY : An Indian Company.
(c) ADDRESS : L & T House, Ballard Estate, Mumbai 400 001, State of
Maharashtra, India
(a) NAME : TAMCO SWITCHGEAR SDN BHD
(b) NATIONALITY: A Malaysian Company
(c) ADDRESS : Sub Lot 24, Lot 16505, Jalan Keluli 1,
P.O. Box 2100, Kawasan Perindustrian Bukit Raja, Seksyen 7, 40000 Shah Alam, Selangor Darul Ehsan, MALAYSIA
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed:

TECHNICAL FIELD OF THE INVENTION
This invention relates generally to a switching apparatus and more particularly to a No load switching apparatus with a racking mechanism for complete protection of the system.
BACKGROUND AND THE PRIOR ART
During service period of a load, it is required to isolate the load. Here the load should be completely isolated and further it should be earthed for complete protection of the system and the service personnel. Thus, there is a need to have a special switch to attain all the aforesaid requirements and such type of switch is commonly known as a NO LOAD SWITCH. This type of switch is able to obtain perfect isolation between input power supplies and the load and later totally connecting the load to earth.
The present invention provides to a unique three-position disconnecting switch using two parallel paths with multiple contact fingers and a mechanism that uses the concept of a racking screw and nut. This switch can be used at places where no load isolation is necessary and further to be connected to earth for complete protection during service period. The mechanism utilizes a racking screw and nut that is connected to a rotating shaft that operates the contact system between three positions. Multiple contact fingers are used to provide sufficient electro-dynamic force withstand capability and a positive contact overlap during service condition.
This invention relates to a NO LOAD SWITCH that is capable of isolating a load and further connecting it to EARTH. The racking mechanism enables the NO LOAD SWITCH to operate from ON to OFF and then EARTH and vice versa. The unique contact system enables the NO LOAD SWITCH to be capable of withstanding higher electro-dynamic forces.
OBJECTS OF THE INVENTION
A basic object of the present invention is to overcome the disadvantages/drawbacks of the known art.

Another object of the present invention is to provide a No load switching apparatus with a racking mechanism for complete protection of the system.
Another object of the present invention is to provide operation with a positive indication for the user.
Another object of the present invention is to provide unique contact system arrangement for higher electro-dynamic forces withstand capability.
Another object of the present invention is to provide an innovative arrangement of racking mechanism and contact system for less operational torque involved for a manual switch.
Another object of the present invention is to provide for a compact system involving less number of components.
Yet another object of the present invention is to ease manufacturability of components and assembly in less time.
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
There is provided a No load switching apparatus with a racking mechanism for complete protection of the system.
According to one embodiment of the present invention, there is provided an operation with a positive indication for the user.
Other embodiment of the present invention provides a unique contact system arrangement for higher electro-dynamic forces withstand capability.

Other embodiment of the present invention provides an innovative arrangement of racking mechanism and contact system for less operational torque involved for a manual switch.
Other embodiment of the present invention provides for a compact system involving less number of components.
Yet other embodiment of the present invention provides for ease in manufacturability of components and less assembly time.
Additionally, the present system provides complete protection of the service personnel as it isolates and further connects it to the earth. The system is optimized in terms of material used resulting into cost effective product. The invention offers flexible/adjustable arrangement for various variants offered.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. 1 illustrates the enclosure and the operating handle of the switch.
Fig. 2 illustrates the switch without the enclosure.
Fig. 3 illustrates the isometric view of the switch at OFF position.
Fig. 4 illustrates the side view of the switch at OFF position.
Fig. 5 illustrates the isometric view of the switch at ON position.
Fig. 6 illustrates the side view of the switch at ON position.
Fig. 7 illustrates the isometric view of the switch at EARTH position.
Fig. 8 illustrates the side view of the switch at EARTH position.
Fig. 9 illustrates the isometric view when operating from OFF to ON position.

Fig. 10 illustrates the side view when operating from OFF to ON position.
Fig. 11 illustrates the isometric view when operating from OFF to EARTH position.
Fig. 12 illustrates the side view when operating from OFF to EARTH position.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The following drawings are illustrative of particular examples for enabling methods of the present invention, are descriptive of some of the methods, and are not intended to limit the scope of the invention. The drawings are not to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description.
Reference is first invited to Fig 1 where the enclosure (1) and handle (2) is shown. The housing for the mechanism and contact system is shown.
Fig. 2 shows the switch without the enclosure. It shows support insulator (3) to support contact terminals.
Fig. 3 & 4 shows isometric view and side view of the switch at OFF position respectively. It shows arrangement for connection for current transfer.
Fig. 5 & 6 shows isometric and side view of the switch at ON position respectively. It shows operating shaft, Racking screw and racking unit.
Fig. 7 & 8 shows the isometric and side view of the switch at EARTH position. It shows link, contact system and contact fingers.
Fig. 9 & 10 shows the isometric and side view of the switch when operating from OFF to ON position.

Fig. 11 & 12 shows the isometric and side view of the switch when operating from OFF to EARTH position.
The invented system is thus a No load switching apparatus with a racking mechanism for complete protection of the system.
DETAILED DESCRIPTION OF THE INVENTION
Accordingly the present invention provides a unique three-position disconnecting switch using two parallel paths with multiple contact fingers and a mechanism that uses the concept of a racking screw and nut. The mechanism utilizes a racking screw and nut that is connected to a rotating shaft that operates the contact system between three positions. Multiple contact fingers are used to provide sufficient electro-dynamic force withstand capability and a positive contact overlap during service condition.
Following are the components / terminologies used in the present invention:
1. Enclosure: Is the housing for the mechanism and contact system.
2. Operating handle: Device used to operate the mechanism.
3. Support Insulator: Is the part to support contact terminals.
4. Terminals: Arrangement for connection for current transfer.
5. Operating shaft: Is a part of mechanism that transmits the motion from the mechanism to the contact system.
6. Racking screw: Racking screw is a part of the racking mechanism, which drives the racking nut.
7. Racking nut: Racking nut is a part of the racking mechanism, which is driven by the racking screw, which in turn rotates the operating shaft.
8. Link: The link used to transmit the motion of the rotating shaft to the contact system.
9. Contact system: The arrangement of the copper blade and contact fingers responsible for current transfer and isolation, which is driven by the mechanism.

10. Contact fingers: Is the part of the contact system that engages with the terminals and ensures current transfer.
The different states of the switch and the related parts thereof are further explained below in detail:
Switch at OFF position: The state in which the contact system (9) is in OFF position and in an isolated condition as shown in Fig. 3 & 4.
Switch ON: The operating handle (2) is rotated in a clockwise direction as shown in Fig. 9 & 10, thereby causing the racking screw (6) to rotate and in turn to move the racking nut (7) in a direction as shown in Fig. 10. This results in rotation of the operating shaft (5) as shown in Fig. 9 & 10. Thus the link (8) is pushed in the direction shown is Fig. 10, thereby causing the contact system (9) to rotate in an anti-clockwise direction as shown in Fig. 10. Thus the no-load switch is operated from OFF to ON position as shown in Fig. 2, 5,&6.
Similarly rotating the operating handle (2) in anti-clockwise direction operates the no-load switch from ON to OFF.
Switch EARTH: The operating handle (2) is rotated in an anti-clockwise direction as shown in Fig. 11 & 12, thereby causing the racking screw (6) to rotate and in turn to move the racking nut (7) in a direction as shown in Fig. 12. This results in rotation of the operating shaft (5) as shown in Fig. 11 & 12. Thus the link (8) is pushed in the direction shown is Fig. 12, thereby causing the contact system (9) to rotate in a clockwise direction as shown in Fig. 12. Thus the no-load switch is operated from OFF to EARTH position as shown in Fig. 7 & 8.
Similarly rotating the operating handle (2) in clockwise direction operates the no-load switch from EARTH to OFF.
Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the embodiments herein with modifications. However, all such modifications are deemed to be within the scope of the claims.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the embodiments described herein and all the statements of the scope of the embodiments which as a matter of language might be said to fall there between.

WE CLAIM:
1. A No load switching apparatus with a racking mechanism providing for three position
disconnection for isolating a load and further connecting it to EARTH comprising:
an enclosure (1) providing housing for the mechanism and contact system (9);
a racking screw (6) and racking nut (7) connected to a rotating shaft that operates the contact system (9) between three positions;
an operating handle (2) to operate the mechanism;
a plurality of supporter insulator (3) to support contact terminals;
a plurality of terminals (4) arranged for current transfer;
an operating shaft (5) transmitting the motion from the mechanism to the contact system;
a link for transmitting the motion of the rotating shaft to the contact system; and
a plurality of contact fingers (10) that engages with the terminals and ensures current transfer.
2. A No load switching apparatus as claimed in claim 1 wherein multiple contact fingers are adapted to provide sufficient electro-dynamic force withstanding capability and a positive contact overlap during service condition.
3. A No load switching apparatus with a racking mechanism providing for three position disconnection for isolating a load and further connecting it to EARTH as herein substantially described and illustrated with reference to the accompanying drawings.