FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
&
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 charging system for a closing spring of a circuit breaker mechanism.
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030, Maharashtra, India, an Indian Company
INVENTOR
Desale Rajgopal and Kalpesh Mandlik of Crompton Greaves Ltd, Switchgear, S3 -Division, A3 - MIDC, Ambad, Nashik, Maharashtra, India; an Indian National.
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:
The field of the invention relates to mechanical equipment and systems.
Particularly, this invention relates to circuit breaker mechanisms.
Still particularly, this invention relates to a charging system for a closing spring of a circuit breaker mechanism.
Background of the Invention:
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.
Prior Art:
Figure 1 illustrates a schematic of the closing spring and its associated mechanism for charging, in a circuit breaker mechanism of the prior art.
In existing circuit breaker mechanisms, a Ratchet-pawl mechanism with motor is used to charge a closing spring. Charging time of the closing spring is a critical factor. It depends on torque required to charge the spring. Closing spring is guided in a metallic drum which is fixed to mechanism frame. Motor is used to charge the closing spring via the ratchet-pawl mechanism. It includes a ratchet wheel (2)

adapted to be angularly displaced through its 360 degree rotation cycle. It further includes a co-axially (7) fitted drum (3), attached to it at its base. A shaft (4) is connected to the ratchet wheel, spaced-apart from the centre of the ratchet wheel, and hangs down into said drum. The drum, includes a co-axially fitted closing spring, which is compressed in its charged-up configuration. There is provided an end plate (5), at the operative bottom of the drum and spring, connected to the operative bottom end of the shaft.
This mechanism works as a slider crank mechanism. As the ratchet wheel angularly displaces, the connected shaft moves up and down (6). This connecting shaft is used to transfer the forces from ratchet wheel to bottom of closing spring i.e. at the end plate. During the rotation of wheel, there is change in angle of connecting rod. This motion, brings the end plate operatively upwards, and this force results in the compression of the closing spring, thus charging it to be used, upon detection fault.
It has been observed that the goodness of a circuit breaker is a function of its charging time, the amount of torque / energy spent on charging, the ease of charging, and the charging to idle time ratio. Also, in the above mechanism, that the shaft is tilted (not always co-axial) due to its connecting arrangement and the drum remains fixed, co-axially, which results in exulting lateral pressure on the inner walls of the drum, and causing friction, thereby requiring more energy to be spent on charging / compressing said spring.
There is a need to obviate the concerns of the prior art.

US5280258A discloses a circuit breaker charging mechanism and its components where in the rod is affixed at its bottom end to a pin to support spring and the document,
US7696447 discloses a mounting assembly that includes connectors extending outwardly to mount the spring energy assembly.
However, there is no disclosure of meant for achieving reduced angle travel of crank or reducing effort or time.
Objects of the Invention:
An object of the invention is to reduce the charging time of a closing spring in a circuit breaker assembly with ratchet wheel.
Another object of the invention is to reduce the torque required for a charging (compressing) a closing spring in a circuit breaker assembly with ratchet wheel.
Yet another object of the invention is to reduce the cost of the charging system (due to power consumption) in a circuit breaker assembly with ratchet wheel.
Still another object of the invention is to reduce the charging to idle time ratio.
Summary of the Invention:
According to this invention, there is provided a charging system for a closing spring of a circuit breaker mechanism, said system comprises:

a. ratchet wheel adapted to be angularly displaced about its centre, resulting in
its rotation, said ratchet wheel having a first axis of installation;
b. spring adapted to be placed operatively beneath said ratchet wheel;
c. drum guide, spaced apart from said ratchet wheel, adapted to house said
spring, said drum and said spring have a laterally shifted second axis with
respect to the first axis of said ratchet wheel;
d. end plate adapted to be located operatively beneath said spring;
e. pivoted plate adapted to pivot said drum guide to a base, thereby supporting
said drum guide which is spaced apart from said ratchet wheel; and
f. shaft with a first end adapted to be attached to said ratchet wheel and a
second end adapted to be connected to an end plate, said shaft linearly
displacing up and down, thus pulling the end plate towards the ratchet
wheel, and thereby resulting in compression of the spring.
Typically, said shaft is a shaft having its axis operatively vertically tilted with respect to the vertical axis of the drum guide and spring and laterally offset with respect to said ratchet wheel.
Typically, said system includes a crank at said first end where said shaft connects to said ratchet wheel.
Brief Description of the Accompanying Drawings:

Figure 1 illustrates a schematic of the closing spring and its associated mechanism for charging, in a circuit breaker mechanism of the prior art.
The invention will now be described in relation to the accompanying drawings, in which:
Figure 2 illustrates a schematic of the charging system for a closing spring of a circuit breaker mechanism.
Detailed Description of the Accompanying Drawings:
According to this invention, there is provided a charging system for a closing spring of a circuit breaker mechanism.
Figure 2 illustrates a schematic of said charging system (100) for a closing spring of a circuit breaker mechanism.
In accordance with an embodiment of this invention, there is provided a ratchet wheel (10) adapted to be angularly displaced about its centre, resulting in its rotation. Typically, said ratchet wheel has a first axis (11) of installation with respect to the system.
In accordance with another embodiment of this invention, there is provided a spring (12) adapted to be placed operatively beneath said ratchet wheel. Typically, said spring is a closing spring, which should be compressed in order for said circuit breaker to be operatively charged.

In accordance with yet another embodiment of this invention, there is provided a drum guide (14), spaced apart from said ratchet wheel, adapted to house said spring. Typically, said drum and said spring have a laterally shifted axis with respect to the axis of said ratchet wheel. Typically, laterally shifted axis is a second axis (13).
In accordance with still another embodiment of this invention, there is provided an end plate (16) adapted to be located operatively beneath said spring.
In accordance with still another embodiment of this invention, there is provided a shaft (18) with a first end adapted to be attached to said ratchet wheel and a second end adapted to be connected to an end plate. Typically, the axis of the shaft is in line with the axis of the drum guide and spring, and hence, laterally offset with respect to said ratchet wheel.
In accordance with an additional embodiment of this invention, there is provided a pivoted plate (20) adapted to pivot said drum guide to a base, thereby supporting said drum guide which is spaced apart from said ratchet wheel.
As the ratchet wheel rotates, the associated shaft linearly displaces up and down (21), thus pulling the end plate towards the ratchet wheel, and thereby resulting in compression of the spring. Due to its spaced apart nature, the drum also moves laterally (24), along with the shaft.

The axis of connecting shaft movement and the ratchet wheel is offset to reduce the charging time. The drum guide for spring is pivoted to reduce the frictional forces between the spring and the drum guide. This reduces the torque requirement from the motor which, in turn, reduces the charging time of for the closing spring of circuit breaker.
The angle of travel of crank (22) is reduced, typically, by 10 degrees, thus resulting in reduction in charging time (typically, by 5.5 %) and reduction in power, typically, by 10%.

We claim,
1. A charging system for a closing spring of a circuit breaker mechanism, said system comprising:
a. ratchet wheel adapted to be angularly displaced about its centre, resulting in
its rotation, said ratchet wheel having a first axis of installation;
b. spring adapted to be placed operatively beneath said ratchet wheel;
c. drum guide, spaced apart from said ratchet wheel, adapted to house said
spring, said drum and said spring have a laterally shifted second axis with
respect to the first axis of said ratchet wheel;
d. end plate adapted to be located operatively beneath said spring;
e. pivoted plate adapted to pivot said drum guide to a base, thereby supporting
said drum guide which is spaced apart from said ratchet wheel; and
f. shaft with a first end adapted to be attached to said ratchet wheel and a
second end adapted to be connected to an end plate, said shaft linearly
displacing up and down, thus pulling the end plate towards the ratchet
wheel, and thereby resulting in compression of the spring.
2. A system as claimed in claim 1 wherein, said shaft is a shaft having its axis operatively vertically tilted with respect to the vertical axis of the drum guide and spring and laterally offset with respect to said ratchet wheel.
3. A system as claimed in claim 1 wherein, said system includes a crank at said first end where said shaft connects to said ratchet wheel.