FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
COMPLETE SPECIFICATION (See section 10 and rule 13)
1. TITLE OF THE INVENTION:
"Arrangement For Engagement Of Front Mounted Add-On Block To Electrical
Contactor"
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. 0. Box: 278, Mumbai 400 001, India
3. PREAMBLE TO THE DESCRIPTION:
COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.

Arrangement For Engagement Of Front Mounted Add-On Block To
Electrical Contactor
Field of the invention
The present invention relates generally to an electrical contactor, and more particularly, to an arrangement for engagement of a front mounted add-on block to electrical contactor.
Background of the invention
Electrical contactor is used as switching device in switchgear for making and breaking of electric circuit. The electrical contactor includes an auxiliary switching device coupled thereto. The auxiliary switching device is required for signaling or providing command to a secondary device. The auxiliary switching device, also called add-on block gets engaged with the electrical contactor mechanically to operate as per the operation of the electric contactor.
US Patent No. 5197594 discloses an arrangement to couple an auxiliary switch mechanism to an electrical switchgear unit, preferably a contactor, with a contact slide piece onto which the moving contact pieces are mounted, and a switchgear housing onto which the switchgear fixed-mounted contact pieces are mounted. However, this kind of arrangement of the auxiliary switch mechanism to an electrical contactor requires lot of components and are difficult for manufacturing.
Accordingly, there exist a need to provide an arrangement for engagement of front mounted add-on block i.e. of the auxiliary switching device to electrical contactor, which overcomes drawbacks of the prior art.
Objects of the invention

An object of invention is to provide an arrangement which give improvement towards fixing arrangement on separate poles and enable engagement of add-on block bridge coupling.
Another object of the present invention is to provide arrangement of a front mounted add-on block to an electric contactor, which easy for manufacturing and higher productivity.
Summary of the invention
Accordingly, the present invention provides an arrangement for engagement of front mounted add-on block to an electrical contactor in a switchgear. The arrangement comprises a bridge assembly configured on the electric contactor. The bridge assembly includes a contact holder mounted thereon. The bridge assembly further includes a first thermoplastic components and a second thermoplastic component mounted thereon. The first thermoplastic component is attached to the contact holder at one side of two middle poles thereof and the second thermoplastic component is attached to contact holder at another side of two middle poles thereof. The first thermoplastic component and the second thermoplastic component includes a slot portion to secure the contact holder therein, an opening for engaging eyelet rivet, and a profile for enabling engagement of add-on block bridge therein. The arrangement further includes a plurality of spring loaded contacts mounted on the contact holder of the bridge assembly. The bridge assembly travels to operate the plurality of spring loaded contacts, thereby making and breaking electric current during switching operation of the electrical contactor.
Brief description of the drawings
Figure 1 shows an arrangement for engagement of a front mounted add-on block to an electrical contactor, in accordance with the present invention;

Figure 2 shows an assembly of an electric contactor and a bridge assembly, in accordance with the present invention;
Figure 3 shows a bridge assembly with thermoplastic components of the electrical contactor of figure 1;
Figure 4 shows a partition made of thermoplastic component which comprises round shaped flexible portion of the thermoplastic components of figure 3; and
Figure 5 shows various elements of thermoplastic components of figure 4.
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.
The present invention provides an arrangement for engagement of front mounted add-on block such as an auxiliary switching device to an electrical contactor in a switchgear. For engaging the front mounted add-on block to the electric contactor, the electric contactor is provided with a bridge assembly which contains an insulating material component, a contact holder and a plurality spring loaded contacts mounted thereon. Specifically, the contacts are meant to carry electric current. During switching operation of the electrical contactor, the bridge assembly travels to operate contact thereby making and breaking the electric current.
Referring now to figures 1-5. there is shown an arrangement for engagement of front mounted add-on block (110) (also known as such as an auxiliary

switching device) to an electrical contactor (120) in a switchgear. in accordance with the present invention. Specifically, figure I shows the arrangement (100). The arrangement (100) comprises a bridge assembly (30) and a plurality of spring loaded contacts (40).
The bridge assembly (30) is configured on the electric contactor (120) as shown in figure 2. The bridge assembly (30) includes a contact holder (10) mounted thereon. Further, the bridge assembly (30) includes an insulating material component configured thereon. Specifically, the insulating material component is a first thermoplastic components (15) and a second thermoplastic component (20) mounted on the bridge assembly (30) as shown in figure 3.
The first thermoplastic component (15) is attached to the contact holder (10) at one side of two middle poles (not shown). Specifically, the first thermoplastic component (15) is attached to contact holder (10) by mean of eyelet rivet. In an embodiment, the first thermoplastic component (15) is attached to contact holder (10) by thermal welding of protruded portion at one side of two middle poles.
Further, the second thermoplastic component (20) is attached to contact holder (10) at another side of two middle poles. Specifically, the second thermoplastic component (20) is attached to the another side of two middle poles of the contact holder (10) by mean of eyelet rivet, in the form of mirror image of the first thermoplastic component (15). In an embodiment, the second thermoplastic component (20) is attached to contact holder (10) by thermal welding of protruded portion. The first thermoplastic component (15) and the second thermoplastic component (20) includes a unique shape with a slot portion (22) to fix contact holder (10), and an opening (24) to inseit eyelet rivet therein. Further, the first thermoplastic component (15) and the second thermoplastic component (20) have a unique profile to enable engagement of add-on block (110) to bridge thereon. Various elements of the first thermoplastic component

(15) and the second thermoplastic component (20) described above are shown in figures 4 and 5.
Furthermore, the plurality of spring loaded contacts (40) are mounted on the contact holder (10) of the bridge assembly (30). The bridge assembly (30) travels to operate the plurality of spring loaded contacts (40) thereby making and breaking electric current during switching operation of the electrical contactor (120).
With complete assembly of the electric contactor (120), while mounting of add-on block (110), such as auxiliary switching device thereon, a bridge of the add-on block (110) gets engaged with unique profile of both side thermoplastic components (15, and 20).
Advantages of the invention
1) The arrangement (100) is an improved arrangement for engaging the front mounted add-on block (110) to the electric contactor (120).
2) The arrangement (100) gives improvement towards fixing arrangement on separate poles.
3) The arrangement (100) is easy for manufacturing and has higher productivity.
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 forms 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. An arrangement for engagement of front mounted add-on block
to an electrical contactor in a switchgear, the arrangement comprising:
a bridge assembly configured on the electric contactor, the bridge assembly having,
a contact holder mounted thereon, and
a first thermoplastic components and a second thermoplastic component mounted thereon, the first thermoplastic component attached to the contact holder at one side of two middle poles and the second thermoplastic component attached to contact holder at another side of two middle poles, the first thermoplastic component and the second thermoplastic component having.
a slot portion to secure the contact holder therein,
an opening, and
a profile for enabling engagement of add-on block bridge therein; and
a plurality of spring loaded contacts mounted on the contact holder of the bridge assembly, wherein a bridge assembly travels to operate the plurality of spring loaded contacts, make and break electric current during switching operation of the electrical contactor.
2. The arrangement for engagement of front mounted add-on block to an electrical contactor as claimed in claim I, wherein the first thermoplastic component and the second thermoplastic components are attached to the contact holder by mean of eyelet rivet.
3. The arrangement for engagement of front mounted add-on block to an electrical contactor as claimed in claim 1. wherein the first thermoplastic

component and the second thermoplastic components are attached to the contact holder by thermal welding.