DESC:TECHNICAL FIELD
The present invention is related to stored energy operating mechanism used in circuit breaker for switchgear products. The present invention provides a motorized operating mechanism of circuit breaker with dynamic latch arrangement to assist positive closing of the circuit breaker.

BACKGROUND AND THE PRIOR ART
Circuit breakers such as moulded case circuit breakers (MCCBs) are used for switching and / or protection in electrical distribution network. These are generally used in incomers and there are cases where it is required to operate breaker from remote (using electrical pulse) for ease of operation and to build logic circuit such as change-over. For these type of applications, accessory called as motorized operating mechanism is supplied.
During switching ON, knob holder of stored energy operating mechanism has to carry breaker knob beyond cross over point (toggle point) of breaker mechanism and hold there for sufficient time till breaker mechanism responds and make contacts ON. If there is no locking mechanism to hold knob holder, it is possible that knob holder can bounce back beyond toggle point of mechanism and again go to final position. Due to time lag between bounce back and going back, breaker will not close with sufficient energy. Hence it puts limitation on breaker design and manufacturing to achieve toggle point much before, so that during bounce back of motorized mechanism, crossover of toggle point does not occur.
1. Latch to avoid pole re-closing in L&T U-POWER ACB : Fig 14 shows latch used in U-POWER ACBs
Working: In normal position, latch is in position as shown Image 14. When contacts are opened by mechanism, after complete opening, they try to re-close because of bounce back effect to some extent. With arrangement of latching, after closing is complete, due to moment of inertia, latch lifts up against gravity. When pole tries to close again, it restricts motion of poles against fixed pin.
Limitation / Difference with present invention:
It works on principle of gravity. Hence it can be used only for breakers with fix mounting position and cannot be mentioned in cases where multiple mounting positions are required. Also this art is used to avoid contact re-closing in air circuit breakers and not for operating knob, hence functional area is different.
2. Latch to avoid pole re-closing in Schneider ACB: Fig 15 shows latch used in Schneider ACBs
Working: In normal position, latch is moved towards shaft because of torsion spring. When contacts are open out, they try to close back because of bounce back effect to some extent. Here, after poles are completely opened up, due to centrifugal force, it latch moves out due to centrifugal force. When contacts try to close again, it restricts motion of poles.
Limitation / Difference with present invention:
This art is used to avoid contact re-closing in air circuit breakers and not for operating knob hence functional area is different. Also, spring is supported by split pin which also acts as stopper for latch. Where as in our invention, torsion spring is directly mounted on latch and latch profile is modified to act as stopper. Hence one component requirement is eliminated.
The present invention provides a motorized operating mechanism of circuit breaker with dynamic latch arrangement to assist positive closing of the circuit breaker and provides locking arrangement for motorized mechanism during its reverse travel. This will allow breaker even with toggle point occurring late to be used with motorized operating mechanism and ensure positive closing of breaker.

OBJECTS OF THE INVENTION
A basic object of the present invention is to overcome the disadvantages/drawbacks of the known art.
Another object of the present invention is to provide a latch arrangement for motorized operating mechanism of circuit breaker, therefore ensuring positive closing of breaker with cross over point
Another object of the present invention is to provide flexibility in circuit breaker design and manufacturing.
These and other advantages of the present invention will become readily apparent from the following detailed description read in conjunction with the accompanying drawings.

SUMMARY OF THE INVENTION
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.
In an aspect of the present invention, there is provided an arrangement for motorized operating mechanism in the circuit breaker, said arrangement comprising: a gear assembly comprises: a pinion(s), at least two mounting plate mounted on said pinion(s) using a screw, at least two latch connected to said pinion(s), a torsion spring connected between said latch and said pinion for providing a torque in anticlockwise direction; a stored energy mechanism comprises: a knob holder for holding a knob, a tension spring for storing energy, a rack connected to a side plate using a rack pin, a latch rivet and a fix rivet connected to said side plate; wherein said latch contacted to said latch rivet in reverse travel of said knob holder due to centrifugal force of said latch during switching ON condition, therefore said latch restricting the movement of said knob holder to keep said knob holder beyond its crossover point toward ON position of said knob and facilitate positively switching ON said circuit breaker.
Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The following drawings are illustrative of particular examples for enabling methods of the present invention, are descriptive of some of the methods, and are not intended to limit the scope of the invention. The drawings are not to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description.
Figure 1 illustrates the perspective view of gear assembly
Figure 2 illustrates the sectional view of gear assembly
Figure 3 illustrates the perspective view of motorized mechanism (standalone)
Figure 4 illustrates the perspective view of motorized mechanism with circuit breaker in OFF condition
Figure 5 illustrates the perspective view of motorized mechanism with circuit breaker in ON condition
Figure 6 illustrates the front view of motorized mechanism with circuit breaker in OFF position
Figure 7 illustrates the detailed view of gear assembly and latch rivet when unit is in OFF position
Figure 8 illustrates the front view of motorized mechanism with circuit breaker in maximum travel position or ON position
Figure 9 illustrates the detailed view of gear assembly and latch rivet when unit is in maximum travel position or ON position
Figure 10 illustrates the front view of motorized mechanism with circuit breaker in maximum travel position towards ON with latch moves outward due to centrifugal force
Figure 11 illustrates the detailed view of gear assembly and latch rivet when unit is in maximum travel position towards ON with latch moves outward due to centrifugal force
Figure 12 illustrates the front view of motorized mechanism with circuit breaker towards ON with maximum bounce back
Figure 13 illustrates the detailed view of gear assembly and latch rivet when unit is towards ON with maximum bounce back.
Figure 14 (PRIOR ART) illustrates the latch used in U-POWER ACBs.
Figure 15 (PRIOR ART) illustrates the latch used in Schneider ACBs.
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.
Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION OF THE INVENTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.
By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.
Accordingly, present invention provides a latch arrangement for motorized operating mechanism of circuit breaker during its reverse travel. This will allow breaker even with toggle point occurring late to be used with motorized operating mechanism and ensure positive closing of breaker.
Present invention provides a motorized operating mechanism, more particularly stored energy type, where spring is charged during breaker RESET / OFF. This spring energy is released for switching ON the breaker. During switching ON, spring which is connected to knob holder discharges and carries breaker knob along.
Construction:
A) Gear Assembly
Fig 1 and Fig 2 depicts construction of gear assembly. It contains pinion 1A on which dynamic assembly is mounted. Pinion 1A has holes and internal tapping on which mounting plate 1B is mounted with the help of screws 1F. Rivet 1D is fixed to mounting plate by process such as spin riveting. Torsion spring 1E is mounted on rivet 1D such that its one end rests against pinion1A, and other is hooked to dynamic latch 1C. This spring ensures that dynamic latch 1C is always rests against pinion1A by providing torque in anticlockwise direction as shown in Fig 2. Shape of latch 1C is such that, it has inbuilt stopper to allow only specific rotation around rivet 1D as it stops against pinion 1A.
B) Stored energy motorized operating mechanism with circuit breaker
Fig 3 shows motorized operating mechanism. This type of mechanism works on stored energy principle. It contains tension spring, one end of which is mounted on fix rivet 2D which is fixed to side plate 2C. Other end of spring is hooked to rack pin 2AB of knob holder 2A. It is possible to rotate pinion 1A through handle or motor (mechanism which transfers motion from handle or motor to pinion 1A is not shown). This rotary motion is converted into translator motion of knob holder 2A because of rack and pinion arrangement.
Fig 4 and Fig 5 shows motorized mechanism with circuit breaker. Knob holder 2A of stored energy mechanism 2 is engaged with knob 3AA of circuit breaker 3. Translation motion of knob holder carries knob and make circuit breaker switch ON or switch OFF.
Description of parts
1. Gear Assembly
1A: Pinion
1B: Mounting plate
1C: Dynamic latch
1D: Rivet
1E: Torsion spring
1F: Mounting screw
2. Stored energy mechanism
2A: Knob holder
2AA: Rack
2AB: Rack pin
2B: Main spring
2C: Side plate
2D: Fix rivet
2E: Latch rivet
3. Combination Unit
3A: Circuit breaker
3AA: Knob of circuit breaker
Working:
A) Spring charging / resetting operation
Please refer Fig 3 and Fig 4.This operation is done through handle or charging motor (not shown). This motion is transferred to rotary motion of pinion 1A which in turn converted to translation motion of knob holder 2A. Knob holder 2A carries knob 3AA of circuit breaker and takes it to OFF / RESET position. During this operation, spring is extended and energy is stored in spring. At final position, motion is locked with D-shaft (not shown) so that rack 2AA does not move because of spring force.
B) Spring discharge / Switching ON
Refer Fig 4. At this position, spring is energized and pinion 1A is locked with D shaft. Breaker is in OFF condition. For switching ON, pinion is made free by rotating D-shaft. Thus, due to energy in spring, knob holder moved in direction as shown in Fig 3. During this operation, knob holder 2A carries knob 3AA of breaker and takes it from OFF position (Fig. 4) to ON position (Fig.5). To complete this operation it is required that knob holder 2A carries knob 3AA beyond cross over point (toggle point) of breaker and holds it there.
C) Working of dynamic latch.
Refer Fig 6 and Fig 7.Unit is in steady state OFF condition. As soon as ON command is given, D shaft is rotated (not shown) and due to energy in spring, knob holder is moved and takes position of maximum travel as shown in Fig 8 while carrying knob 3AA along. During this journey, there is no relative motion between pinion 1A and latch 1C (Refer Fig 9). When knob holder hits at last position, due to centrifugal force and center of gravity of dynamic latch, latch 1C moves outward against torsion spring force 1E (Refer Fig 10 and Fig 11) and remains in that place for small duration f time due to inertia. After knob holder hits last position, it starts coming back against main spring force due to restitution. During its reverse travel, latch 1C hits against latch pin 2E (Refer Fig 12 and Fig 13). Hence its reverse travel is restricted to the extent of gap between latch 1C and fix pin 2E as in Fig 11. This keeps knob 3AA beyond its cross over point towards ON and ensures that breaker is made ON positively. This allows breakers with cross over point value as low as allowable bounce back as mentioned to get switched ON positively.
NOVEL FEATURE:
· In general, it is required to use circuit breaker with cross over point that occurs early to have proper functioning (switching ON) with motorized operating mechanism. This puts limitation on design of basic circuit breaker. Novelty lies in dynamic latch arrangement, where, it positively ensures switching ON even with circuit breakers with cross over point that occurs comparatively later. This provides flexibility in circuit breaker design and manufacturing.
· Yet another advantage of invention is, it operates on centrifugal force phenomenon, hence it can be worked with any mounting position of circuit breaker without getting affected by gravity.
· There are two dynamic latches that are working. Hence another advantage of using multiple numbers is, in case of failure of one, even if one works correctly, required function is achieved. If both dynamic latches work simultaneously, life of parts is increased.
· Yet another advantage is, since impact is taking by mechanical components which are hardened, life of parts is higher.
,CLAIMS:1. An arrangement for motorized operating mechanism in the circuit breaker, said arrangement comprising:

a gear assembly comprises: a pinion(s), at least two mounting plate mounted on said pinion(s) using a screw, at least two latch connected to said pinion(s), a torsion spring connected between said latch and said pinion for providing a torque in anticlockwise direction;

a stored energy mechanism comprises: a knob holder for holding a knob, a tension spring for storing energy, a rack connected to a side plate using a rack pin, a latch rivet and a fix rivet connected to said side plate;

wherein said latch contacted to said latch rivet in reverse travel of said knob holder due to centrifugal force of said latch during switching ON condition, therefore said latch restricting the movement of said knob holder to keep said knob holder beyond its crossover point toward ON position of said knob and facilitate positively switching ON said circuit breaker.

2. The arrangement as claimed in claim 1, wherein said pinion (s) having plurality of holes and internal tapping for mounting said mounting plate.

3. The arrangement as claimed in claim 1, wherein said gear assembly having a rivet fixed on said mounting plate(s) through a spin riveting, therefore said latch rotates around said rivet.

4. The arrangement as claimed in claim 1, wherein one end of said tension spring connected to said fix rivet whereas other end connected to said rack pin, therefore said tension spring stores energy during extension.
5. The arrangement as claimed in claim 1, wherein said pinion is rotates through an operating means, therefore rotary motion of said pinion converted into translator motion of said knob holder due a rack and pinion arrangement.

6. The arrangement as claimed in claim 5, wherein said operating means is a handle and/or motor.

7. The arrangement as claimed in claim 1, wherein said tension spring extended during rotation of said pinion, and said pinion locked with a D-shaft when said knob holder attain a final position, therefore stopping the movement of said rack, thereby switching OFF said circuit breaker by moving said knob in OFF/RESET position.

8. The arrangement as claimed in claim 1, wherein said D-shaft rotates during switching ON of circuit breaker, therefore said tension spring facilitate movement to said knob holder due to energy stored in said tension spring.

9. The arrangement as claimed in claim 9, wherein said knob holder travel the maximum position, thereafter said latch contacted with said latch rivet during its reverse travel for restricting the movement of said knob holder beyond the crossover point toward ON position, thereby facilitate switching ON condition of said circuit breaker.