FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2005
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A closing and charging system for circuit breakers.
APPLICANT(S)
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR(S)
Nimone Dharmaraj and Roy Deosharan; both of Crompton Greaves Ltd, Analytics Centre, CG Global R&D Centre, Kanjurmarg (E), Mumbai-400042, Maharashtra, India; both Indian Nationals.
PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

FIELD OF THE INVENTION:
This invention relates to the field of mechanical engineering.
Particularly, this invention relates to mechanical assemblies and mechanical engineering with respect to switchgear equipment.
More particularly, this invention relates to closing and charging systems in circuit breakers.
Specifically, this invention relates to a closing and charging system for circuit breakers.
BACKGROUND OF THE INVENTION:
The term 'switchgear', used in association with the electric power system, or grid, refers to the combination of electrical disconnects, earthing-switches and/or circuit breakers used to isolate electrical equipment and networks. Switchgear is used both to de-energize equipment to allow maintenance work to be done and to clear faults.
Switchgear equipment comprises circuit breaker mechanisms. Circuit Breaker mechanisms are used in electrical equipment, as an adjunct mechanism, for preventing said electrical equipment from current / voltage aberrations such as overload, short circuit, or the like. Basically, it is designed to detect a fault condition, and operates to interrupt the working of the associated electrical equipment upon detection, thereby saving its health.
Once a fault is detected, contacts within the circuit breaker must open to interrupt the circuit; some mechanically-stored energy (using something such as springs or

compressed air) contained within the breaker is used to separate the contacts. Small circuit breakers may be manually operated; larger units have coils to trip the mechanism, and electric motors to restore energy to the springs.
A trip coil is a type of solenoid in which the moving armature opens a circuit breaker or other protective device when the coil current exceeds a predetermined value. A closing coil is adapted to shut the circuit breaker completely.
In its working mode, if a power surge occurs in the electrical system, the breaker will trip. This means that a breaker that was in the "on" position will flip to the "off position and shut down the electrical power leading from that breaker. Essentially, a circuit breaker is a safety device. When a circuit breaker is tripped, it may prevent a fire from starting on an overloaded circuit; it can also prevent the destruction of the device that is drawing the electricity.
A close coils is a coil which closes the circuit breaker electrically using an external voltage source when a specified voltage is applied across the coil.
The operating mechanism, of a circuit breaker, consists primarily of two tension springs; 1) tripping spring; and 2) closing spring. The closing spring generates the required driving force to close the circuit breaker and charge the tripping spring. The tripping spring is directly connected to the circuit breakers link system. This means that the mechanical energy needed for the vital opening operation is always stored in the tripping spring when the circuit breaker is in closed position. In other words, a closed circuit breaker is always prepared for immediate opening.
A universal motor drives the spring charging gear, which automatically charges the closing spring immediately after each closing operation. The springs are kept in

charged state by a latch that is released when the circuit breaker is being closed. This enables rapid reclosing of the circuit breaker after a pre-defined dead time interval.
Prior art systems are riddled with problems and disadvantages, as listed below:
1. Assembly of eccentric shaft pawl is difficult.
2. Pawl wear.
3. Ratchet wheel is bulky.
4. Higher energy loss in charging system.
OBJECTS OF THE INVENTION:
An object of the invention is to provide a one way charging and backstopping system for circuit breakers.
Another object of the invention is to provide a closing and charging system for circuit breakers without the use of pawl(s).
Yet another object of the invention is to provide a closing and charging system for circuit breakers which eliminates problems arising due to pawl wear.
Still another object of the invention is to provide a closing and charging system for circuit breakers which is relatively less bulky.
An additional object of the invention is to provide a closing and charging system for circuit breakers where there is relatively lesser energy loss in the charging system.

SUMMARY OF THE INVENTION:
According to this invention, there is provided a closing and charging system for circuit breakers adapted to perform an open-close-reopen operation, said system comprises:
a. a first resilient means operated by a two phase lever located on a pole rod of
said circuit breaker, said first resilient means' operative bottom end being fixed
with support and its operative top end being free, thereby adapted to exert
torque in an operative upward direction in order exert force on said two phase
lever to open said circuit breaker;
b. a second resilient means being fixed at its operative bottom end;
c. cam shaft adapted to be eccentrically coupled to said second resilient means at
one end and with an idler sprocket and associated simplex chain, said cam
shaft adapted to be angularly displaced in one way direction through anti
clockwise direction;
d. a main sprocket adapted to be mounted on said cam shaft, said main sprocket
further adapted to be connected to a spring shoe through a connecting pin and
chain;
e. an intermediate small sprocket adapted to be mounted on an intermediate shaft
adapted to be connected to said main sprocket by a chain arrangement;
f. a backstopping clutch having an inner race and an outer race, said
backstopping clutch adapted to be mounted on said intermediate shaft at its
said inner race with said outer race of said backstopping clutch anchored
stationary by a torque arm adapted to be fitted into a stationary ground member
of said circuit breaker;
g. an overrunning clutch adapted to be mounted on a charging motor shaft;
h. a one-way motor adapted to be angularly displaced in one way, due to said overrunning clutch; and

i. multiple stages of sprockets adapted to transmit power from said motor to said second resilient means.
Typically, said first resilient means is a tripping helical spring.
Typically, said second resilient means is a closing helical spring.
Typically, multiple stages of chain sprockets are advantageously arranged for achieving a desired speed of operation.
Typically, said one-way motor is a motor adapted to work in an anticlockwise direction due to said overrunning clutch.
Typically, said multiple stages of sprockets comprise a small intermediate sprocket adapted to be fitted on said one end of said backstopping clutch.
Typically, said multiple stages of sprockets comprises a big intermediate sprocket adapted to be mounted on said other end of said backstopping clutch.
Typically, said multiple stages of sprockets comprise a charging motor sprocket adapted to be connected with said big intermediate sprocket by a chain arrangement.
Typically, said one-way motor is adapted to be angularly displaced in one way, due to said overrunning clutch, thereby driving said motor sprocket adapted to be mounted coaxially on said overrunning clutch to said intermediate big sprocket by connecting a chain drive arrangement.

Typically, said system comprises a charged first resilient means in closed condition of said circuit breaker.
Typically, said system comprises a charged second resilient means in closed condition of said circuit breaker.
Typically, said motor shaft is adapted to work as freewheel due to overrunning clutch during closing of said circuit breaker and simultaneous charging of said first resilient means.
Typically, said system comprises a limit switch adapted to disconnect power supply to said motor when said second resilient means is fully charged.
Typically, said system comprises a holding latch system adapted to hold a charged second resilient means till next operation.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figures la, lb, 2, and 3 illustrates a closing and charging system of the prior art.
The invention will now be described in relation to the accompanying drawings, in which:
Figures 4, 5, and 6 illustrate various views of the closing and charging system for circuit breakers in accordance with this invention.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figures la, lb, 2, and 3 illustrates a closing and charging system of the prior art, in its various views.
In this system, the spring-spring mechanism consists of a tripping helical spring (1) and a closing helical spring (2). The closing spring (2) is charged through a motor driven cam (6), ratchet mechanism (4), and pawl (10).
Referring to Figures la and lb of the accompanying drawings, when breaker is in closed condition (closing spring charged) both, closing spring (2) and tripping spring (1), are in charged position. The tripping spring (1) exerts a torque through a two phase lever (3) to a pole of the circuit breaker. When the tripping spring (trip coil) is energized, a lever (7) is released from a latching system and is angularly displaced in an operative downward direction to attain an open position. During closing operation, closing spring (2) exerts a torque on a cam (6) and ratchet wheel (4). When the closing spring (closing coil) is energized, the cam (6) angularly displaces in counter clockwise direction and, in turn, the lever (7) is angularly displaced in clockwise direction. This lever (7) motion closes the circuit breaker and charges the tripping spring (1) at the same time. At the end of closing operation, ratchet moves beyond bottom dead centre due to inertia mass and momentum. It is stopped by using a stopper wheel and pawl mechanism.
Referring to Figures 2 and 3, it can be seen that, immediately after the breaker is closed, the closing spring charging motor (5) gets activated through a limit switch. The closing spring (2) is charged by the ratchet (4) and multiple pawl (10) mechanism which is linked to the motor (5). Pawls are mounted on eccentric shaft. When the closing spring (2) is fully charged, the limit switch disconnects the

power supply to motor (5) and closing holding latch system holds the compressed spring energy till next operation.
Prior art systems are riddled with problems and disadvantages, as listed below:
1. Assembly of eccentric shaft pawl is difficult.
2. Pawl wears.
3. Ratchet wheel is bulky.
4. Higher energy loss in charging system.
According to this invention, there is provided a closing and charging system for circuit breakers. This invention specifically relates to spring loaded operating mechanism for high voltage circuit breaker, for performing an open-close-reopen operation. This invention is particularly for one way charging, chain attachment from connecting pin to spring shoe, and backstopping system in (high voltage) circuit breaker.
In accordance with an embodiment of this invention, there is provided a first resilient means (tripping helical spring) (1) operated by a two phase lever (3) located on a pole rod of a circuit breaker. When this first resilient, first resilient means (tripping helical spring) (1) exerts a force on the two phase lever (3), breaker is open.
In accordance with another embodiment of this invention, there is provided a second resilient means (closing helical spring) (2). When breaker is in closed condition (second resilient means being charged), both, closing spring 2 and tripping spring (1) are in charged position.

Figures 4, 5, and 6 illustrate various views of the closing and charging system for circuit breakers in accordance with this invention.
Referring to Figures 4 and 5 of the accompanying drawings, it can be seen that, the first resilient means' (tripping helical spring) (1) operative bottom end is fixed with support and its operative top end is free. This arrangement exerts a torque in operative upward direction. When the trip coil is energized, the first resilient means (tripping helical spring) (1) releases and opens the circuit by using a movement of spring and two phase lever (3).
In accordance with yet another embodiment of this invention, there is provided a cam shaft (17), simplex chain (15), and idler sprocket mechanism (14). The second resilient means (closing helical spring) (2) is fixed at bottom end and eccentrically coupled to the cam shaft by a simplex chain (15) with idler sprocket (14). The cam shaft is angularly displaced in one way direction through anti-clockwise direction.
In accordance with still another embodiment of this invention, there is provided a main sprocket (4) mounted on the cam shaft. The main sprocket (4) connects through connecting pin (9) and chain to a spring shoe (16). An intermediate small sprocket which is mounted on an intermediate shaft (10) connects to main sprockets (4) by chain arrangement.
In accordance with an additional embodiment of this invention, there is provided a backstopping clutch (8) having an inner race and an outer race, the backstopping clutch (8) being adapted to be mounted on the intermediate shaft (10), at its inner race. The outer race of the clutch anchored stationary by torque arm is fitted into the breaker stationary ground member. On either direction of the backstopping

clutch (8), there is mounted a small and big intermediate sprocket (11), respectively.
In accordance with yet an additional embodiment of this invention, there is provided a charging motor sprocket (12) connected with big intermediate sprocket (11) by a chain arrangement.
In accordance with still an additional embodiment of this invention, there is provided an overrunning clutch (13) mounted on the charging motor shaft. Multiple stages of chain sprockets are advantageously arranged for achieving a desired speed of operation.
During closing operation, closing spring (2) is released in an operative upward direction. This closes the (associated) circuit by using a rotary movement from the main sprocket (4) which is connected to the closing spring (2) by chain attachment link (9). Anticlockwise angular displacement of the main sprocket (4) rotates the cam (6) to move two phase lever (3). This actuates lever (7) and this lever (7) motion closes the circuit breaker and charges the tripping spring (1) at the same time; in said operation, the motor shaft works as freewheel due to overrunning clutch (13). Release of closing spring (2) results in acquiring of inertia force and momentum, due to which the spring (2) moves beyond a bottom dead centre position and tries to come back (to its earlier position) but gets stopped due to the backstopping clutch (8). The backstopping clutch prevents the main sprocket (4) to move backwards when the spring has reached its extreme position and tries to come back. Thus, the kinetic energy of the system can be used to partially charge the spring and prevention of reverse rotation helps in settling down the spring movement fast so that motor can start the charging of closing spring.

In accordance with an embodiment of this invention, there is provided a one-way motor (5). Referring to Figures 5 and 6 of the accompanying drawings, the motor (5) is a one-way motor which angularly displaces in one way; in anticlockwise direction due to overrunning clutch (13), thereby driving the motor sprocket (12) which is mounted coaxially on the overrunning clutch (13) to the intermediate big sprocket (11) by connecting a chain drive arrangement. Immediately after the breaker is closed, the spring charging motor (5) gets activated. The closing spring (2) is charged by the chain sprocket by multiple stages of power transmission arrangement. When the closing spring (2) is fully charged, the limit switch disconnects the power supply to motor (5) and closing or holding latch system holds the compressed spring energy till next operation.
The Technical Advancement of this invention lies in providing a closing and charging system for circuit breakers which have the following advantage: I. It is a compact mechanism as compared to the prior art; II. ratchet pawl system is eliminated which results in lesser number of components as compared to the prior art;
III. improved the reliability of charging system due to backstop;
IV. providing a simplex chain and sprocket with overrunning clutch arrangement for charging of closing spring; and
V. Providing a backstopping clutch to stop the reverse rotation of cam shaft.
While this detailed description has disclosed certain specific embodiments of the present invention for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly

understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We claim,
1. A closing and charging system for circuit breakers adapted to perform an open-close-reopen operation, said system comprising:
a. a first resilient means operated by a two phase lever located on a pole
rod of said circuit breaker, said first resilient means' operative bottom
end being fixed with support and its operative top end being free,
thereby adapted to exert torque in an operative upward direction in
order exert force on said two phase lever to open said circuit breaker;
b. a second resilient means being fixed at its operative bottom end;
c. cam shaft adapted to be eccentrically coupled to said second resilient
means at one end and with an idler sprocket and associated simplex
chain, said cam shaft adapted to be angularly displaced in one way
direction through anti-clockwise direction;
d. a main sprocket adapted to be mounted on said cam shaft, said main
sprocket further adapted to be connected to a spring shoe through a
connecting pin and chain;
e. an intermediate small sprocket adapted to be mounted on an
intermediate shaft adapted to be connected to said main sprocket by a
chain arrangement;
f. a backstopping clutch having an inner race and an outer race, said
backstopping clutch adapted to be mounted on said intermediate shaft at
its said inner race with said outer race of said backstopping clutch
anchored stationary by a torque arm adapted to be fitted into a
stationary ground member of said circuit breaker;
g. an overrunning clutch adapted to be mounted on a charging motor shaft;

h. a one-way motor adapted to be angularly displaced in one way, due to
said overrunning clutch; and i. multiple stages of sprockets adapted to transmit power from said motor
to said second resilient means.
2. The closing and charging system for circuit breakers as claimed in claim 1, wherein said first resilient means is a tripping helical spring.
3. The closing and charging system for circuit breakers as claimed in claim 1, wherein said second resilient means is a closing helical spring.
4. The closing and charging system for circuit breakers as claimed in claim 1 wherein, multiple stages of chain sprockets are advantageously arranged for achieving a desired speed of operation.
5. The closing and charging system for circuit breakers as claimed in claim 1, wherein said one-way motor is a motor adapted to work in an anticlockwise direction due to said overrunning clutch.
6. The closing and charging system for circuit breakers as claimed in claim 1, wherein said multiple stages of sprockets comprising a small intermediate sprocket adapted to be fitted on said one end of said backstopping clutch.
7. The closing and charging system for circuit breakers as claimed in claim 1, wherein said multiple stages of sprockets comprising a big intermediate sprocket adapted to be mounted on said other end of said backstopping clutch.

8. The closing and charging system for circuit breakers as claimed in claim 1, wherein said multiple stages of sprockets comprising a charging motor sprocket adapted to be connected with said big intermediate sprocket by a chain arrangement.
9. The closing and charging system for circuit breakers as claimed in claim 1, wherein said one-way motor is adapted to be angularly displaced in one way, due to said overrunning clutch, thereby driving said motor sprocket adapted to be mounted coaxially on said overrunning clutch to said intermediate big sprocket by connecting a chain drive arrangement.
10. The closing and charging system for circuit breakers as claimed in claim 1, wherein said system comprising a charged first resilient means in closed condition of said circuit breaker.
11. The closing and charging system for circuit breakers as claimed in claim 1, wherein said system comprising a charged second resilient means in closed condition of said circuit breaker.
12. The closing and charging system for circuit breakers as claimed in claim 1, wherein said the motor shaft adapted to work as freewheel due to overrunning clutch during closing of said circuit breaker and simultaneous charging of said first resilient means.
13. The closing and charging system for circuit breakers as claimed in claim 1, wherein said system comprising a limit switch adapted to disconnect power

supply to said motor when said second resilient means is fully charged.
14. The closing and charging system for circuit breakers as claimed in claim 1, wherein said system comprising a holding latch system adapted to hold a charged second resilient means till next operation.