FORM 2
THE PATENTS ACT, 1970
(39 of l970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
Circuit Breaker Mechanism
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR
Nimone Dharmaraj Khushal, of Crompton Greaves Ltd, Analytics Lab, Global R&D, Kanjur Marg, Mumbai 400 042, Maharashtra, India, an Indian National.
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
This invention relates to a circuit breaker mechanism. Particularly, this invention relates to a rack and pinion device for spring loaded operating mechanism for linear displacement of high voltage circuit breaker.
BACKGROUND OF THE INVENTION
Circuit breaker mechanisms are used in various applications. The application of the present invention relates to switchgears or gas insulated switchgear (GIS) or air insulated switchgear (AIS) systems.
The prior art in relation to the field of the present invention is described with reference to the following figures wherein the same numerals relate to the same parts and wherein:
Fig 1 illustrates the cross sectional rear view of the system with helical springs in the
prior art.
Fig 2 illustrates the cross sectional front view of the system with helical springs in the
prior art
Fig 3 illustrates the cross sectional side view of the system with helical springs in the
prior art.

As shown in the figures 1 to 3, the mechanism consists of a tripping helical spring 2 and a closing helical spring 1. The closing helical spring 1 is charged through a motor driven cam 6, a pawl 5 and a ratchet mechanism 4.
When the breaker is in closed condition (closing spring charged) - both the closing helical spring 1 and the tripping helical spring 2 are in charged position. The tripping helical spring 2 exerts a torque through two phase lever 3 to a pole 7. At this stage a locking device called a trip holding latch 8 avoids the lever movement. When the trip helical spring is energized, the two phase lever 3 is released from the trip holding latch 8 and rotates in a clockwise direction (downward direction) to attain an open position.
Figure 1 shows the charging of the tripping helical spring, wherein the closing helical spring 1 which is fixed on the top side exerts a torque on the cam 6 and the ratchet wheel 4. When the closing coil is energized, the cam 6 rotates in a counter clock wise direction and in turn, the lever 10 is rotated in clockwise direction. This lever 10 motion closes the circuit breaker and charges the tripping spring 2 at the same time.
As shown in Figure 3, immediately after the breaker is closed, the spring charging motor 11 gets activated through a limit switch (not shown in the figure). The closing spring 1 is charged by the ratchet 4 pawl 5 mechanism which is linked to the motor 11. When the closing spring 1 is fully charged, the limit switch disconnects the power supply to motor 11 and a closing - holding latch 9 holds the compressed spring energy till next operation.

The aforesaid prior art encounters various drawbacks. To cite few, there is breakage on the pawl tip. Further, over travel of closing spring during closing operation occurs which causes wear and tear of the parts. For charging a closing spring, numbers of components in assembly are more.
Considering the above there is need to provide a rack and pinion device for spring loaded operating mechanism for linear displacement of high voltage circuit breaker.
OBJECTIVE OF THE INVENTION
An objective of the invention is to provide a mechanism for high voltage circuit breaker, for performing an open-close-reopen operation.
SUMMARY OF THE INVENTION
According to one aspect of the invention, there is provided a mechanism for a circuit breaker comprising;
a) a sliding pole adapted to be substantially in a vertical position;
b) a sliding rack operatively mounted on said sliding pole;
c) a shaft adapted to be substantially in a horizontal position;
d) a pinion mounted on said shaft; wherein said pinion is operatively engageable and/or disengageable with said sliding rack;
e) a sprag clutch mounted on said shaft;
f) a chain sprocket arrangement mounted on said sprag clutch;
g) a motor coupled to said chain sprocket arrangement;

h) a lever coupled to said shaft; wherein said lever is adapted to be substantially in a
perpendicular position to said shaft; i) a plurality of springs; wherein one of said plurality of springs defines a closing spring
mounted on said lever, another said plurality of springs defines a tripping spring
mounted on said sliding pole;
wherein energizing of said tripping spring enables said sliding rack to disengage with
said pinion to open said circuit breaker, and/or
wherein energizing of said closing spring enables said sliding rack to engage with
said pinion to close said circuit breaker.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
These and other aspects, features and advantages of the invention will be better understood with reference to the following detailed description and the accompanying drawings, in which the same numerals indicate the same parts and wherein:
Fig 4 illustrates the cross sectional front view of the present invention.
Fig 5 illustrates the cross sectional rear view of the present invention.
Fig 6 illustrates the isometric cross sectional front view of the present invention.
Fig 7 illustrates the isometric cross sectional rear view of the present invention

DETAILED DESCRIPTION OF THE INVENTION WITH THE ACCOMPANYING DRAWINGS
As a preliminary matter, the definition of the term "or" for the purpose of the following discussion and the appended claims is intended to be an inclusive "or" that is, the term "or" is not intended to differentiate between two mutually exclusive alternatives. Rather, the term "or" when employed as a conjunction between two elements is defined as including one element by itself, the other element itself, and combinations and permutations of the elements. For example, a discussion or recitation employing the terminology "A" or "B" includes: "A" by itself, "B" by itself and any combination thereof, such as "AB" and/or "BA." It is worth noting that the present discussion relates to exemplary embodiments, and the appended claims should not be limited to the embodiments discussed herein.
The present invention relates to spring loaded operating mechanism for high voltage circuit breaker, for performing an open-close-reopen operation. A tooth shaped rack mounted on the vertical sliding pole and an X-shaped gear pinion mounted on a horizontal shaft is used for closing the circuit breaker. The tripping helical spring connects coaxially with the pole rod of the breaker. When the breaker is in closed condition (the closing spring charged), both the closing and tripping springs are in charged position. A chain and sprocket with sprag clutch arrangement is used for charging of the closing spring.

With reference to figure 4, the tripping helical spring 2 is coaxial with the pole 7 axis. The top end of the tripping helical spring 2 is fixed with support and bottom end of the tripping helical spring is free which exerts a torque on downward direction but trip holding latch 8 avoids the pole movement. A toothed rack 13 mounted on the sliding pole 7 and above the trip holding latch 8. The X-shaped pinion 12 mounted on the horizontal shaft 18. When the trip coil is energized, the pole 7 is released from a substantially round shaped latch 14. The pole 7 rotates in a predetermined downward direction to attain an open position. The gap is formed between the sliding rack 13 and the stationary pinion 12 due to discontinuity of tooth. The X-shaped pinion 12 has a discontinuity in its teeth, this discontinuity generating a gap which constitutes a zone without teeth on either direction. The X-shaped pinion 12 has a teeth shape on top and bottom side.
Referring to Figure 5, the closing helical spring 1 is fixed at the bottom end and is eccentrically coupled to the horizontal shaft 18 by the lever 10. The horizontal shaft 18 is free to rotate about an axis due to the sprag freewheel clutch 17 during the closing operation. A large toothed chain sprocket 15 coaxially mounted on the sprag clutch 17 along the axis of the horizontal shaft 18. The sprag clutch 17 mounted on the horizontal shaft 18 and transmits a power one way direction from outer to inner race when outer race drives by motor through connection of chain and sprocket arrangement. When the closing coil is energized, the roller mounted on the toothed chain sprockets 15 disengages from the closing holding latch 9 and closed the circuit breaker by the rack teeth 13 meshed in engagement with the X- shaped pinion teethl2, said pinion 12 having a rotation of 180°. The closing spring lever 10 is rotated in clockwise direction along the horizontal shaft 18. This lever 10 motion closes the circuit breaker and charges the tripping spring 2 at the same time.

From Figures 6 and 7, the motor 11 is used to charge the closing spring 1 is coupled to a small toothed sprockets 16 to the large toothed sprocket 15 by the chain 19 drive arrangement. The large toothed sprocket 15 is mounted coaxially on the sprag clutch 17, said clutch is mounted on the horizontal shaft 18. The horizontal shaft 18 rotates in one way direction via clockwise due to the sprag clutch 17. The motor 11 is a one-way motor, driving the large toothed sprocket 15 by connecting the chain 19 arrangements. Immediately after the breaker is closed, the spring charging motor 11 gets activated through a limit switch. The closing spring 1 is charged by the chain sprocket mechanism. It is linked by the chain 19 from the motor 11 to the large toothed sprocket 15 to internally the sprag clutch 17 to the horizontal shaft 18. When the closing spring 1 is fully charged the limit switch disconnects the power supply to the motor 11 and the closing - holding latch system 9 holds the compressed spring energy till next operation.
The present invention has a compact mechanism with a simple construction and less moving parts, which reduces the friction amongst the parts. Reliability of the present invention is better than the conventional mechanisms. The present invention uses a single shaft without a cam, which plays both the roles due to the free wheel clutch, as compared to existing multi-shaft with cams. Further the Ratchet-pawl-system is eliminated. Over travel problem in closing spring is also eliminated. The present invention also reduces the rate of charging of motor and reduces the assembly time.
Although the invention has been described with reference to a specific embodiment, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiment, as well as alternate embodiments of the invention, will become apparent

to persons skilled in the art upon reference to the description of the invention, It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the invention as defined.

We Claim
1. A mechanism for a circuit breaker comprising:
a) a sliding pole adapted to be substantially in a vertical position;
b) a sliding rack operatively mounted on said sliding pole;
c) a shaft adapted to be substantially in a horizontal position;
d) a pinion mounted on said shaft; wherein said pinion is operatively engageable and/or disengageable with said sliding rack;
e) a sprag clutch mounted on said shaft;
f) a chain sprocket arrangement mounted on said sprag clutch;
g) a motor coupled to said chain sprocket arrangement;
h) a lever coupled to said shaft; wherein said lever is adapted to be substantially in a
perpendicular position to said shaft; i) a plurality of springs; wherein one of said plurality of springs defines a closing spring mounted on said lever, another said plurality of springs defines a tripping spring mounted on said sliding pole;
wherein energizing of said tripping spring enables said sliding rack to disengage with said pinion to open said circuit breaker, and/or
wherein energizing of said closing spring enables said sliding rack to engage with said pinion to close said circuit breaker.
2) The mechanism as claimed in claim 1, further comprises a roller mounted on said chain sprocket arrangement.

3) The mechanism as claimed in claim 1, further comprises at least one of: a tripping holding latch, a substantially round shaped latch or a closing holding latch.
4) The mechanism as claimed in claim 1, wherein said sliding pole displaces in downward direction when said tripping spring is energized.
5) The mechanism as claimed in claim 1, wherein said pinion is a substantially X-shaped pinion.
6) The mechanism as claimed in claim 3, wherein said tripping holding latch and/or said substantially round shaped latch is adapted for connecting to said sliding pole.
7) The mechanism as claimed in claim 3, wherein said closing holding latch is adapted for
connecting to said chain sprocket arrangement.
8) The mechanism as claimed in claim 1, wherein said sliding rack is adapted for being
located above said tripping holding latch.