FORM 2
THE PATENT ACT 1970
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule13)
1. TITLE OF THE INVENTION:
"A stacking and mounting arrangement for modular electrical devices"
2. APPLICANT:
(a) NAME: Larsen & Toubro Limited
(b) NATIONALITY: Indian Company registered under the
provisions of the Companies Act-1956.
(c) ADDRESS: Larsen & Toubro Limited
L&T House, Ballard Estate,
P.O Box No. 278, Mumbai 400001, INDIA.
3. PREAMBLE TO THE DESCRD7TION:
COMPLETE
The following specification
particularly describes the invention and the manner in which it is to be performed.

A stacking and mounting arrangement for modular electrical devices
Field of invention
The present invention relates to poles of modular electrical switches, and more particularly to a stacking arrangement adapted for the pole of the modular electrical switch.
Background of the invention
Generally, the electrical switches having modular construction are preferred over traditional electrical switches as they are capable of attaining complete isolation between the poles. In these switches, complete isolation between the poles is highly essential in order to achieve higher current ratings. In this type of arrangement, reliable coupling between the poles is of utmost importance.
The prior art stacking arrangements, between two different poles as well as stacking of the two switch disconnectors, are achieved by means of the moulded components and stacking screws. In these stacking arrangements, the load due to slight misalignment of the poles is taken by the moulded components. However, these moulded components are incapable of withstanding higher loads like that of metals components. Also, the rotors between the two adjacent poles of these disconnectors are completely engaged with no space between the housings.
Accordingly, there exists a need of a stacking arrangement between poles of the switch disconnectors that overcomes all the drawbacks of the prior art.
Objectives of the invention
An objective of the present invention is to provide a rigid stacking arrangement between the poles of a switch disconnector.

Another objective of the present invention is to provide effective heat dissipation between the poles of a switch disconnector.
Further objective of the present invention is to provide a rigid stacking arrangement between two switch disconnectors in a changeover switch disonnector.
Summary of the invention
Accordingly, the present invention provides a modular switch disconnector for stacking two adjacent poles thereof in addition to stacking poles of two different switch disconnectors thereby forming an integrated single changeover switch disconnector. The modular switch disconnector comprises a stacking arrangement. The stacking arrangement includes a plurality of stacking plates and a plurality of stacking screws. The stacking plates position on a mechanism before positioning of the modular poles thereon. The mechanism includes a housing that further includes a plurality of protrusions. The protrusions mount the stacking plates thereon. The stacking screws run through the modular poles and the stacking plates thereby engaging with the mechanism. The housing includes a plurality of holes that engages with the stacking screws thereby defining a first clearance. The stacking screws engage with a plurality of holes on the stacking plate thereby defining a second clearance. The,modular switch disconnector comprises a mounting arrangement that includes a first pair of cross nuts that position into a cavity of the housing of the modular poles thereby facilitating positioning of the mounting plates thereon. The first clearance is essentially kept relatively higher than the second clearance to impart rigidity and robustness to the stacking arrangement. The stacking plates prevent physical deterioration of a plurality of mouldings of the mechanism. The stacking plates facilitate a room for dissipation of heat from a rotor coupling of the switch disconnector thereby ensuring sufficient cooling thereof. The mounting arrangement includes at least one mounting bracket adapted to add robustness to the stacking arrangement.

Brief description of the drawings
FIG. 1 is a front view of a centre operated changeover switch disconnector constructed in accordance with the present invention;
FIG. 2 is an exploded front view of the changeover switch disconnector of FIG. I;
FIG. 3 is a cross sectional view taken along a stacking plate of the changeover switch disconnector of FIG. 1;
FIG. 4 is a perspective view of the stacking plate of the changeover switch disconnector of FIG. 1;
FIG. 5 is a cross sectional view of a mounting arrangement in a housing of changeover switch disconnector of FIG. 1;
FIG. 6 is a perspective view of a cross nut used in the mounting arrangement of FIG. 5;
FIG. 6b is an expanded cross sectional view of the mounting arrangement of FIG.5;and
FIG. 7 is perspective view showing the mounting arrangement of FIG.5 integrated with the stacking arrangement of FIG. 1.
Detailed description of the invention
The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.

Accordingly, the present invention provides a modular switch disconnector for stacking two adjacent poles thereof in addition to stacking poles of two different switch disconnectors thereby forming an integrated single changeover switch disconnector through a stacking arrangement and a mounting arrangement as described in detail hereinafter.
Referring to FIGS. 1-2, a stacking arrangement 100 adapted for switch disconnector and constructed in accordance with the present invention is shown that preferably facilitates stacking of two adjacent poles of single switch disconnector 100 (as shown in FIG. 1) in this one preferred embodiment. However, it is understood here that the stacking arrangement 100 is configured to facilitate stacking of the poles of the two different switch disconnectors 100 integrated into single changeover switch disconnector (as shown in FIG. 2).
The stacking arrangement 100 includes a plurality of stacking plates 101 that are adapted to be positioned on a mechanism 102. The stacking arrangement 100 includes a plurality of modular poles 103. The stacking plates 101 are adapted to be positioned before mounting of modular poles 103 on the mechanism 102 in this one preferred embodiment. The modular poles 103 are such that a pair of switch disconnectors 104 is stacked one above other therein.
As shown in FIGS. 3-4, the mechanism 102 has a housing that includes a plurality of protrusions 105. The protrusions 105 are adapted to mount the stacking plates 101 on the housing. The stacking arrangement 100 includes a plurality of stacking screws 106 that run through the poles 103 and the stacking plates 101 thereby engaging with the mechanism 102. The stacking screws 106 facilitate stacking of all the modular poles 103 on. the mechanism 102 in this one preferred embodiment.
The housing of poles 103 includes a plurality of holes that engage with the stacking screws 106 thereby defining a first clearance. The stacking screws 106

engage with a plurality of holes 107 on the stacking plate 101 thereby defining a second clearance. In this one embodiment, the first clearance is essentially kept relatively higher than the second clearance to impart rigidity and robustness to the stacking arrangement 100. This allows the stacking plates 101 to sustain stresses under events such as slight misalignment during assembly, twisting of the mechanism 102 during operation and the like. The stacking plates 101 prevent physical deterioration of mouldings of the mechanism 102. The stacking plates 101 also facilitate a room for dissipation of heat from a rotor coupling of the switch disconnector thereby ensuring that there is sufficient cooling to rotor coupling therein.
Referring to FIGS. 5, 6a, 6b and 7, the the stacking arrangement of the switch disconnector integrated with a unique mounting arrangement 108 is shown. The mounting arrangement includes a first pair of cross nuts 109 that is located into a cavity of the housing of the poles 103. In this alternative embodiment, the stacking plates 101 are positioned on the first pair of cross nuts 109. A second pair of cross nuts is placed into cavities of next pole 103. The stacking screw 106 run through these cross nuts 109 in this one particular embodiment. At least one mounting bracket 110 is subsequently positioned and tightened to add robustness to the stacking arrangement 100.
Advantages of the present invention are:
1. The stacking arrangement provides a robust method of stacking poles of the switch-disconnector by means of the stacking plates I.
2. The stacking arrangement provides a robust method of stacking two switch-disconnectors of a changeover switch-disconnector by means of the stacking plates 1.
3. The stacking arrangement provides effective means for dissipating heat between the poles thereby providing effective cooling of the rotor of the switch disconnector.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forrns disclosed, and obviously many modifications and variations are possible in light of the above teaching.
The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.

We Claim:
1. A modular switch disconnector for stacking two adjacent poles thereof in
addition to stacking poles of two different switch disconnectors to form an
integrated single changeover switch disconnector, the modular switch
disconnector comprising:
a plurality of modular poles connecting through a stacking arrangement, the stacking arrangement having a plurality of stacking plates and a plurality of stacking screws, the stacking plates positioning on a mechanism before positioning of the modular poles thereon, the mechanism having a housing including a plurality of protrusions mounting the stacking plates thereon, the stacking screws running through the modular poles and the stacking plates thereby engaging with the mechanism, the housing including a plurality of holes engaging with the stacking screws thereby defining a first clearance, the stacking screws engaging with a plurality of holes on the stacking plate thereby defining a second clearance; and
a mounting arrangement having a first pair of cross nuts positioning into a cavity of the housing of the modular poles facilitating positioning of the mounting plates thereon, the stacking screws running through the cross nuts.
2. The modular switch disconnector as claimed in claim 1, wherein the first clearance is essentially kept relatively higher than the second clearance to impart rigidity and robustness to the stacking arrangement.
3. The modular switch disconnector as claimed in claim 1, wherein the stacking plates prevent physical deterioration of a plurality of mouldings of the mechanism.
4. The modular switch disconnector as claimed in claim 1, wherein the stacking plates facilitate a room for dissipation of heat from a rotor coupling of the switch disconnector thereby ensuring sufficient cooling thereof.

5. The modular switch disconnector as claimed in claim 1, wherein the mounting arrangement includes at least one mounting bracket adapted to add robustness to the stacking arrangement.