FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION:
Rotary Mechanism for Switching Device
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.

Rotary Mechanism for Switching Device
Field of the invention
The present invention relates to a rotary mechanism for switching devices and more particularly, to a top mounted rotary mechanism used in low voltage switchgear products.
Background of the invention
Electrical switching apparatus such as a switch disconnector provides isolation and is capable of making, carrying and breaking currents under normal circuit conditions based on specified operating overload conditions for specific time. These apparatuses also operate under specified abnormal circuit conditions such as short circuit for a specified time. These are suitable for diverse applications in motor control centers, switchboards and as main switches in various equipments and machines. These switches are ideal for withstanding higher short circuit currents for short time duration.
In general, the electrical switching apparatus comprises a contact system and rotary mechanism to actuate the contact system. The contact system is actuated by operating the rotary mechanism from front, rear, left or right sides. The contact system consists of a terminal and a rotor assembly. The rotor assembly includes a rotor, a moving contact, a magnetic cladding and a leaf spring. The electrical switching devices available in the art are manual and hence operated solely by means of directly applied manual energy. As a result, the speed and force of the operation are dependent upon the action of the operator.

Another problem is the installation of the electrical switching apparatus. Since, the electrical switching apparatus is installed into a Distribution Box (DB) and a switch board panel, space is a constraint. Hence, this combination should be accommodated in an optimum space. The rotary mechanism mounted on left or right side of the compact system tends to increase the overall size which is against the panel requirement.
Accordingly, there is a need for a rotary mechanism that is mounted on top of the contact system to overcome the problems in the prior art.
Object of the present invention
An object of the present invention is to provide a top mounted rotary mechanism for a switching device that is compact and enables manual independency.
Sununarv of the invention
Accordingly, the present invention provides a rotary mechanism for a switching device. The switching device includes a contact system. The contact system includes a plurality of first rotors. The rotary mechanism is held between a plate and a cover. The rotary mechanism comprises a plurality of couplers, a connector shaft, a second rotor and an arm.
The plurality of couplers is capable of securing to the plurality of first rotors. Each coupler of the plurality of couplers includes a slot. The connector shaft is configured with at least three protrusions for engaging into the slot of each coupler. The second rotor is mounted on a top surface of one of the first rotor of the plurality of first rotors. The second rotor is adapted to undergo rotation in response to ah

operation of the switching device to DEAD CENTRE position between OFF and ON positions.
The second rotor includes the arm pivoted thereto. The arm includes a spring coiled thereon. The arm includes a means configured thereon for locking an end of the spring therein. The arm moves in response to the rotation of the second rotor to generate energy. The energy is stored in the spring to drive further rotation of the second rotor when the switching device is operated post DEAD CENTRE position. The rotation of the second rotor drives one of the first rotor of the plurality of first rotors. The first rotor drives the plurality of couplers to drive the connector shaft. The connector shaft drives the rotation of remaining first rotors of the plurality of first rotors by converting rotational motion into linear motion thereby resulting in a change in the position of the switching device from OFF position to ON position.
Brief description of the invention
The objectives and advantages of the present invention will become apparent from the following description read in accordance with the accompanying drawings wherein,
Figures 1 -2 show an electrical switching device having a contact system and a top mounted rotary mechanism, in accordance with the present invention;
Figures 3-4 show a top view and a bottom view of the rotary mechanism of figure 1;
Figure 5 shows a perspective view of a second rotor of the rotary mechanism of figure 3;

Figure 6 shows a perspective view of the contact system of figure 1;
Figure 7 is a cross sectional view of the contact system of figure 5 showing a connection of a connector shaft with a coupler;
Figure 8 shows a perspective view of a first rotor of the contact system of figure 5;
Figure 9 shows a perspective view of the connector shaft, in accordance with the present invention;
Figure 10 shows a perspective view of a coupler, in accordance with the present
invention;
Figure 11 shows a perspective view of the contact system and the top mounted rotary mechanism in OFF position, in accordance with the present invention;
Figure 12 shows a perspective view of the contact system and the top mounted rotary mechanism in DEAD CENTRE position, in accordance with the present invention; and
Figure 13 shows a perspective view of the contact system and the top mounted rotary mechanism in ON position, in accordance with the present invention.
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 embodiment.

The present invention provides a rotary mechanism for a switching device. The rotary mechanism is mounted on top of a contact system of the switching device. The rotary mechanism of the present invention is compact and enables manual
independency.
The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various
figures.
Referring now to figures 1-13, there is shown a rotary mechanism (70) for a switching device (100), in accordance with the present invention. Specifically, the switching device (100) is a multi-pole switching device for example, a 3-poIe switch disconnector having a pole width of 17.5 mm, a switch width of 52.5 mm, height of 75 mm and depth of 60 mm. In general, 1 pole means 1 mode that is equal to 17.5 mm pole width. Thus, combined width of 4-poles is 17.5x4 = 70mm. However, it is understood that the dimensions of the switching device (100) may vary in other alternative embodiments.
The switching device (100) comprises a modular contact system (90). The contact system (90) includes a plurality of first rotors (80). The contact system (90) is actuated by the rotary mechanism (70). The rotary mechanism (70) is mounted on a top side (not numbered) of the contact system (90). The rotary mechanism (70) is arranged between a plate (50) and a cover (not shown). The rotary mechanism (70) comprises a plurality of couplers (10), a connector shaft (20), a second rotor (30), and an arm (40). The rotary mechanism (70) is assembled by using any suitable means known in the art.

The plurality of couplers (10) is capable of securing to the plurality of first rotors (80) of the contact system (90). In an embodiment, each coupler of the plurality of couplers (10) is press fitted with the first rotor (80). Each coupler of the plurality of couplers (10) includes a slot (5). The slot (5) is configured for receiving the connector shaft (20). The connector shaft (20) is configured with at least three protrusions (15) for engaging into the slot (5) of each coupler. Thus, the plurality of couplers (10) helps in coupling the connector shaft (20) to the plurality of first rotors (80).
One of the first rotor of the plurality of first rotors (80) includes the second rotor (30) mounted thereon. In other words, the second rotor (30) is mounted on a top surface (not numbered) of one of the first rotor of the plurality of first rotors (80). In an embodiment, the second rotor (30) is a vertical rotor. The second rotor (30) is adapted to undergo rotation in response to an operation of the switching device (100) from OFF position (refer figure 11) to ON position (refer figure 13) through a DEAD CENTRE position (refer figure 12). The DEAD CENTRE position lies between OFF position and ON position. The second rotor (30) includes the arm (40) pivoted thereto.
The arm (40) includes a spring (36) wound/coiled thereon. The arm (40) includes a spring rest (32) configured on an end thereof. Thus, one end (not numbered) of the spring (36) is connected to the second rotor (30) through the arm (40) and a second end (not numbered) of the spring (36) gets locked in the spring rest (32). The spring (36) remains un-charged during OFF position of the switching device (100) and fully charged during DEAD CENTRE position of the switching device (100). The arm (40) is adapted to move in response to the rotation of the second rotor (30) and generates energy. The spring (36) stores the energy.

During the operation of the switching device (100) from OFF position to ON position, the second rotor (30) undergoes rotation. The second rotor (30) is coupled to one of the first rotor (80) in such a way that the second rotor (30) drives the first rotor (80) two degrees before the DEAD CENTRE position. The rotation of the second rotor (30) moves the arm (40) till the DEAD CENTRE position.
At DEAD CENTRE position, the second rotor (30) just touches the first rotor (80).
At DEAD CENTRE position, there occurs no movement of the connector shaft
(20), the plurality of couplers (10) and the first rotor (80). However, at this position,
the spring (36) gets charged due to the arm movement. .
Post DEAD CENTRE position the spring energy is used for driving further rotation
of the second rotor (30) thereby making the rotary mechanism (70) manually
independent. The rotation of the second rotor (30) drives one of the first rotor of the
plurality of first rotors (80). The first rotor (80) drives the plurality of couplers (10)
that in turn drives the connector shaft (20). The connector shaft (20) drives the
rotation of remaining first rotors of the plurality of first rotors (80) by converting
rotational motion into linear motion. As a result, the position of the switching
device (100) changes from OFF position to ON position.
Advantages of the present invention:
1. Since the rotary mechanism (70) is mounted on top of the contact system (90), the performance of the switching device (100) is improved.
2. The rotary mechanism (70) helps to achieve manual independency by means of the coupling arrangement between the second rotor (30) and the first rotor (80) (rotor to rotor coupling).

3. Since manual independent operation of the switching device (100) is performed by using stored energy generated from manual power and releasing the stored energy in one continuous operation, the speed and force of the operation are independent of the action of the operator.
4. The rotary mechanism (70) helps to achieve intentional variable transmission delay by means of the rotor to rotor coupling.
5. The switching device (100) of the present invention is very compact due to
use of less number of components that are simple and light weighted.
6. The rotary mechanism (70) drives the contact system (90) with higher efficiency to transfer energy from vertical motion to horizontal motion and again converting horizontal motion to vertical motion.
7. Each first rotor (80) of the contact system (90) need not carry torque of adjacent first rotor (80) as each first rotor (80) is directly coupled with the rotary mechanism (70).
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the spirit and scope of the invention.

We Claim:
1. A rotary mechanism for a switching device having a contact system
including a plurality of first rotors, the rotary mechanism comprising:
• a plurality of couplers securing to the plurality of first rotors, each coupler of the plurality of couplers having a slot;
• a connector shaft having at least three protrusions configured thereon for engaging into the slot of each coupler of the plurality of couplers;
• a second rotor mounted on a top surface of one of the first rotor of the plurality of first rotor, the second rotor adapted to undergo rotation in response to an operation of the switching device from OFF to ON position; and
• an arm pivoted to the second rotor, the arm having a spring coiled thereon, the arm moves in response to the rotation of the second rotor to generate and store energy in the spring,
wherein, the operation of the switching device to a DEAD CENTRE position between the OFF position and ON position causes rotation of the second rotor and movement of the arm to generate spring energy, the spring energy causes further rotation of the second rotor to drive one of the first rotor of the plurality of first rotors that drives the plurality of couplers, the plurality of couplers drives the connector shaft, the connector shaft drives the rotation of remaining first rotors of the plurality of first rotors by converting rotational motion into linear motion thereby changing the switching device from OFF position to ON position.
2. The rotary mechanism as claimed in claim 1, wherein the arm includes a means configured thereon for locking an end of the spring therein.
3. The rotary mechanism as claimed in claim 1 is held between a plate and a cover.

4. The rotary mechanism as claimed in claim 1, wherein the rotation of the second rotor before DEAD CENTRE position occurs by the operation of the switching device.
5. The rotary mechanism as claimed in claim 1, wherein the rotation of the second rotor after DEAD CENTRE position occurs by utilization of the spring
energy.