FORM 2
The Patents Act 1970
(39 of 1970)
&
The Patent Rules 2003
COMPLETE SPECIFICATION
(See Section 10 and rule 13)
TITLE OF THE INVENTION:
INTERLOCKING MECHANISM FOR ELECTRICAL
CONTRACTORS
APPLICANT:
LARSEN & TOUBRO LIMITED
L&T House, Ballard Estate, P.O. Box No. 278,
Mumbai, 400 001, Maharashtra,
INDIA.
PREAMBLE OF THE DESCRIPTION:
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

A) TECHNICAL FIELD
[0001] The present invention relates to electrical contactor, and more particularly to a mechanical interlocking arrangement for preventing simultaneous closing of a pair of electrical contactors.
B) BACKGROUND OF THE INVENTION
|0002] Electrical contractor is used as switching device in switchgear for making & breaking of electric circuit. In particular, a pair of electrical contactor gets used in case of main and a standby electrical supply in the system. At a given time only one electrical contactor gets closes and makes the electrical circuit. Another electrical contactor shall not get closed. Only if first contactor is open then second electrical contactor shall close.
[0003] Hence, there exists a need to provide an efficient mechanical interlocking arrangement for preventing simultaneous closure of a pair of electrical contactors.
[0004] The above mentioned requirement is addressed herein and which will be understood by reading and sstudying the following specification.
C) OBJECT OF THE INVENTION
[0005] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
[0006] The primary object of the present invention is to provide a sandwich type mechanical interlocking arrangement for preventing simultaneous closing of a pair of electrical contactor.

[0007] Another object of the present invention is to provide a sandwich type mechanical interlocking arrangement which directly gets mounted on electrical contactors.
[0008] Another object of the present invention is to provide a unique profile of the slider and partition in mechanical interlocking arrangement to ensure interlocking function.
[0009] Yet another object of the present invention is to provide a mechanical interlocking arrangement with less components and easy for manufacturing and higher productivity.
[0010] Yet another object of the present invention is to provide a mechanical interlocking arrangement which provides higher life during its operation.
D) SUMMARY OF THE INVENTION
[0011] The various embodiments of the present invention provide interlocking mechanism for electrical contactors . The interlocking mechanism comprises a housing, at least two sliders arranged in the housing and a partition arranged between the at least two sliders. The unique sandwich type of mechanical interlocking which directly gets mounted on the contactors to prevent simultaneous closing of a pair of electrical contactors.
[0012] According to one embodiment of the present invention the mechanical interlocking arrangement includes two sliders and a unique shaped partition assembled in two halves of the housing. The two sliders are made of thermoplastic material placed opposite to each other which gets engaged in contact supporting moving element of the electrical contactor. The unique shaped partition is placed between the two sliders. Each slider travel along with and in the direction of contact supporting moving element of the contactor. The unique

shaped partition is made of thermoplastic and comprises a round shaped flexible portion. The unique shaped partition flex at right angle direction of the slider motion at along the axis of the slider.
[0013] According to an embodiment of the present invention, when both of the contactors are in open state i.e. when the contact supporting moving element of the contactor is in open condition, both sliders of the interlock are positioned together above the round shaped flexible portion of partition. In case of simultaneous closing of the contactor, the motion of both the sliders gets arrested and in turn prevents both the contactors from getting closed.
[0014] According to an embodiment of the present invention, when one of the contactor gets closed, the slider engaged in respective contact supporting moving element of contactor does travel along the slider. During the motion of slider, the round shaped flexible portion partition flex in at right angle direction towards the second slider. In this case, the motion of second slider gets locked which prevent the second contactor from getting closed.
[0015] According to an embodiment of the present invention, a positive interlocking is ensured due to unique profile of slider and partition arrangement in the mechanism. The mechanism is directly mounted on electrical contractors. The tntertocking arrangement has Jess no. of components and is easy for manufacturing and provides higher productivity. The mechanism provides higher life during its operation.
E) BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:

[0017J FIG. 1 illustrates a front perspective view of sandwich type mechanical interlocking arrangement between a pair of electrical contactor according to one embodiment of the present invention.
[0018] FIG. 2 illustrates a side perspective view of the two sliders and one unique shaped partition assembled in two halves of the housing in a mechanical interlock according to one embodiment of the present invention.
(0019] FIG. 3 illustrates an exploded view of a mechanical interlock according to one embodiment of the present invention.
[0020] FIG. 4 illustrates a side perspective view of the unique shaped partition made of thermopiastic which comprises round shaped flexible portion according to one embodiment of the present invention.
[0021] FIG. 5 illustrates a front view of position of both sliders arranged above a round shaped flexible portion of partition at open state according to one embodiment of the present invention.
[0022] FIG. 6 illustrates flexing of a round shaped flexible portion partition at right angle direction towards the second slider according to one embodiment of the present invention.
[0023] Although specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.
F) DETAILED DES CRIPTION OF THE INVENTION

[0024] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.
[0025] The various embodiments of the present invention provide a sandwich type mechanical interlocking arrangement for preventing simultaneous closing of pair electrical contactor. The mechanical interlocking arrangement includes two sliders and a unique shaped partition assembled in two halves of housing. The Two sliders are made of thermoplastic material placed opposite to each other which gets engaged in contact supporting moving element of the electrical contactor. The unique shaped partition is placed in between the two sliders. Each slider does travel along with and in the direction of contact supporting moving element of the contactor. The unique shaped partition is made of thermoplastic and comprises round shaped flexible portion which shall flex in a right angle direction of the slider motion at the axis.
[0026] When both of the contactors are in open state i.e. when contact supporting moving element of contactor is in open condition, both sliders of the interlock are positioned together above the round shaped flexible portion of partition. In case of simultaneous closing of the contactor, the motion of both the sliders gets arrested which in turn prevents both the contactors from getting closed.
[0027] When one of contactor gets closed, the slider engaged in respective contact supporting moving element of contactor travel along with the slider. During the motion of slider, the round shaped flexible portion partition flex in at

right angle direction towards second slider. In this case, the motion of second slider gets locked which prevent second contactor from getting closed.
[0028] FIG, 1 illustrates a front perspective view of a sandwich type mechanical interlocking arrangement between a pair of electrical contactor according to one embodiment of the present invention. With respect to FIG. 1, the mechanical interlock (A) is mounted on and sandwiched between a pair of electrical contactors (B) and (C).
[0029] FIG. 2 illustrates a side perspective view of two sliders and one unique shaped partition assembled in two halves of housing in a mechanical interlock according to one embodiment of the present invention. The FIG. 2 includes two sliders 3 and 4 and one unique shaped partition 5 (as shown in FIG. 3) assembled in the two halves 1, 2 of the housing. The two sliders 3 and 4 are made of a thermoplastic material and are placed opposite to each other and get engaged with the contact supporting moving element of the contactor.
[0030] FIG. 3 illustrates an exploded view of a mechanical interlock according to one embodiment of the present invention. With respect to FIG.3, a unique shaped partition 5 is placed in between the two sliders 3 and 4. Each of the slider
3 and 4 does travel along with and in the direction of the contact supporting
moving element of electrical contactor. The two sliders 3 and 4 and one unique
shaped partition 5 are assembled in two halves of the housing 1 and 2.
[0031] When both of the contactors are in open state i.e. when contact supporting moving element of contactor is also in open condition, both sliders 3,
4 of the interlock are positioned together above the round shaped flexible portion
(as shown in FIG.4) of partition. In case of simultaneous closing of the contactor,
motion of both the sliders 3. 4 shall get arrested and in turn prevents simultaneous
closure of both contactors.

[0032] When one of contactor gets closed, the slider 3 engaged in respective contact supporting moving element of contactor does travel along with the slider 3. During motion of slider, the round shaped flexible portion partition flex in at right angle direction towards second slider 4. In this case, the motion of second slider 4 gets locked which prevent second contactor from getting closed.
[0033] FIG. 4 illustrates a side perspective view of the unique shaped partition according to one embodiment of the present invention. With respect to FIG. 4 the unique shaped partition 5 is made of thermoplastic. The unique shaped partition is provided with a round shaped flexible portion 5a which flexes in at right angle direction of the slider motion along the axis of the movement of the slider.
[0034] FIG. 5 illustrates a front view of the arrangement of the sliders together above the round shaped flexible portion of partition at an open state according to one embodiment of the present invention. With respect to FIG. 5, when both contactor are in open state i.e. when contact supporting moving element of contactor is in also open condition, both sliders 3 and 4 of the interlock are positioned together above the round shaped flexible 5a portion of the partition 5. In case of simultaneous closing of the contactor, motion of both the sliders 3, 4 gets arrested and in turn both contactors are prevented from closing.
[0035] FIG. 6 illustrates a flexing of the round shaped flexible portion partition in at right angle direction towards second slider according to one embodiment of the present invention. With respect to FIG. 6, when one of contactor gets closed, the slider 4 engaged in respective contact supporting moving element of contactor does travel along with the slider 4. During the motion of the slider 4, the round shaped flexible portion 5a of the partition 5 flex in at right angle direction towards the second slider 3. In this case, the motion of the second slider 3 gets locked and thus prevents second contactor from getting closed.

G) ADVANTAGES OF THE INVENTION
[0036] The various embodiments of the invention provide a sandwich type mechanical interlocking arrangement for preventing simultaneous closing of pair electrical contactor. A positive interlocking is ensured due to the unique profile of slider and partition arrangement in the mechanism. The mechanism can be directly mounted on the electrical contactors. The interlocking arrangement has lesser components and is easy for manufacturing and provides higher productivity. The mechanism provides higher life during its operation.
[0037] Although the invention is described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.
[0038] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the present invention described herein and all the statements of the scope of the invention which as a matter of language might be said to fall there between.

CLAIMS
What is claimed is:
1. An interlocking mechanism for electrical contactors, the mechanism
comprising:
a housing;
at least two sliders arranged in the housing; and
a partition arranged between the at least two sliders;
Wherein the partition includes a unique sandwich type of mechanical interlocking
which directly gets mounted on the contactors to prevent simultaneous closing of
a pair of electrical contactors.
2. The interlocking mechanism according to claim 1, wherein the at least two sliders are made of a thermoplastic material.
3. The interlocking mechanism according to claim 1, wherein the at least two sliders are arranged opposite to each other so as to get engaged with a contact supporting moving element of the electric contactors.
4. The interlocking mechanism according to claim 1, wherein the partition is assembled in two halves of the housing.
5. The interlocking mechanism according to claim 1, wherein the partition includes a flexible portion.
6. The interlocking mechanism according to claim 5, wherein the flexible portion is round shaped.
7. The interlocking mechanism according to claim 5, wherein the partition is
made of thermoplastic.

8. The interlocking mechanism according to claim 1, wherein the partition flex at right angles along an axis of at least of the slider during the slider motion.
9. The interlocking mechanism according to claim 1, wherein the sliders are arranged in the housing such that the flexible portion of the partition comes in contact with each other when both of the contactors are in open position.
10. The interlocking mechanism according to claim 1, wherein the sliders are
arranged in the housing such that the movement of the sliders are prevented when
both of the contactors are in closed position.