CLIAMS:1. A mechanism to hold a trip plate (8) in a position to avoid an overriding of latch bracket, comprising:
at least one mounting plate (1,7) with at least one rear end flaring (6);
a latch link (2) with at least one flared portion (4, 5);
at least one upper link (3);
a latch bracket (13);
a fork (9);
at least one lower link (14) assembly (10) further comprising a tension spring (12);
at least one knob (15) to switch a circuit breaker ON or OFF; and
a flipping mechanism to control a latching and de-latching in the circuit breaker.

2. The mechanism in accordance with claim 1, wherein the upper link (3) is coupled with the flared portion (4, 5).

3. The mechanism in accordance with claim 1, wherein the latch bracket (13) is coupled with the at least one rear end flaring (6).

4. The mechanism in accordance with claim 1, wherein the at least one mounting plate (1, 7) is locked between the trip plate (8) and the fork (9).

5. The mechanism in accordance with claim 1, wherein the tension spring (12) at first end is hooked to the fork (9) using a pin (11).

6. The mechanism in accordance with claim 1, wherein the tension spring (12) at second end is hooked to the trip plate (8) and the at least one mounting plate (1, 7).

7. The mechanism in accordance with claim 1, wherein the latching occurs when the latch link (2) presses the latch bracket (13), thereby pressing the tension spring (12) hooked between the latch bracket (13) and trip plate (8) which in turn pulls the trip plate (8).

8. The mechanism in accordance with claim 1, wherein the de-latching occurs when the latch link (2) releases the latch bracket (13), thereby releasing the tension spring (12) hooked between the latch bracket (13) and trip plate (8) which in turn pushes the trip plate (8).
,TagSPECI:TECHNICAL FIELD

The present subject matter described herein, in general relates to a circuit breakers, and more particularly, to a trip system to trip the breaker with the help of accessories.

BACKGROUND

A circuit breaker is a mechanical switching device capable of making, carrying and breaking currents. Under normal circuit conditions it will make the circuit closed, carry current for a specified time and breaks the circuit under specified abnormal circuit conditions.

A Molded Case Circuit Breakers (MCCB) is employed for current interruption. More particularly MCCB’s are utilized to protect instruments from damage during adverse conditions prevailing during the operation of the circuit in which molded case circuit breaker is employed. During adverse conditions like short circuit, the current rises to an alarmingly high level. This high current may cause damage to the parts in the electrical system. Hence during these conditions the circuit has to be opened to protect the parts after the breaker.

A circuit breaker can be manually opened and closed, as well as automatically opened to protect conductors or equipments from damage caused by excessive heating due to over current in abnormal conditions such as overload or short-circuit. The trip system, a part of mechanical system of the circuit breaker plays a vital role in determining the credibility of the breaker. A good mechanical system should ensure quick and manually independent opening of contact system.
Two major operations those are dependent on the trip system in the MCCB mechanism, viz., a TRIP operation and a RESET operation. The trip signal is given by the release which senses the abnormal conditions like short circuit overload and gives TRIP command to the trip plate of trip system in the mechanism, so that the mechanical system opens the circuit. The operator does not have any access to the trip system except Push-to-trip (PTT), otherwise the trip system can receive signal only from a thermo magnetic release. The other internal accessories can also interact with the system through trip plate directly or indirectly with any other integral component.

The other part of the circuit breaker is a Knob. When the knob indicates ON it means the breaker is in ON condition i.e., the current path is closed. Similarly the position of the knob indicates the state of the circuit breaker. According to standards, the top position of the knob (if the breaker is placed vertically) or the longest distant position of the knob away from the operator (if the breaker is mounted horizontally) should be marked as ON POSITION. The other extreme end in both cases is marked as the OFF POSITION. The knob will be near the center (based on the design of the mechanism) to indicate the TRIP POSITION.

The TRIP command is given automatically to the contacts by the release if it senses an abnormal condition like overload and short circuit. If the trip signal is given, the breaker opens the circuit and the knob goes to the trip position to show the operator that a fault has occurred in the system.

If the operator wants to switch ON the breaker after the breaker is tripped, he/she cannot do it without resetting the breaker. This is to make sure that the operator shouldn't switch ON the breaker before clearing the fault.

There are few limitations or drawbacks of the circuit breakers. In general, a Latch bracket latching point on to the trip plate should be normal to the pivot or in the Cos quadrant with respect to the trip plate pivot as center. Due to this, the breakers loses the flexibility to receive its trip command either on top or bottom with respect to the reference of latch bracket latching latch link. Also, the trip system parameters are constrained with respect to the force and travel delivered by the release. Further, because of such mechanism there is chance for Nuisance Tripping.

Incase of Magnetic release, there will be a moving core which is hinged and a fixed core kept above and parallel to the hinge point and the part below the hinge point of the moving core will be used to push the trip plate with force due to the attraction of moving core to the fixed core. The bi-metal is kept in between them which will be a current carrying conductor. Due to magnetic flux, the fixed core attracts the moving core which is hinged. The attraction force is directly proportional to the flux density which is inversely proportional to the gap between moving core and fixed core.

In case of thermal release, the bi-metal is used to push the trip plate (which is common component for the magnetic release) due to the bimetal deflection (Deflection is caused due to heat developed in the system by the current) based on the material. Here the Force and deflection (travel) is gradual.

The trip system parameters are
1. The trip plate torque
2. The perpendicular distance of the trip plate latching point w.r.to its pivot
3. Ideally, the normal force on the trip plate due to the latching of latch bracket should pass through the trip plate pivot.
4. The friction between the latching parts
5. The perpendicular distance from the hitting point to the trip plate pivot
6. The amount of travel required by the trip plate to trip the system.
7. The trip force,
The Point 1, 2 are dependent on main mechanism and pont 3 is tweaked to meet the point 6 & 7 requirements. Normally point 6 & 7 are inpts from the release. When the point 1 is on higher side the point 7 should also be on higher side. But that flexibility will be lost due to Thermo magnetic release constraints.

Due to above mentioned drawbacks; there exists a need to provide an efficient mechanism that can avoid the limitation/drawbacks and perform the operation in an efficient manner.

SUMMARY

This summary is provided to introduce concepts related to a mechanism to hold a trip plate in a position to avoid an overriding of latch bracket. This summary is not intended to identify essential features of the subject matter nor is it intended for use in determining or limiting the scope of the subject matter.

In one implementation, the invention is intended to provide a mechanism to hold a trip plate in a position to avoid an overriding of latch bracket.

In one implementation, the disclosed mechanism holds the trip plate in its position to avoid over riding of latch bracket.

In one implementation, the disclosed mechanism includes a tension spring that helps in keeping the trip plate in its position avoids a nuisance tripping.

In one implementation, the disclosed mechanism provides the flexibility over the trip plate parameters with respect to the release position for tripping.

In one implementation, the disclosed mechanism provides no intricacy in the design to integrate the flip mechanism in the trip system.
In one implementation a mechanism to hold a trip plate in a position to avoid an overriding of latch bracket is disclosed. The mechanism comprises of at least one mounting plate with at least one rear end flaring. The mechanism further comprises of a latch link with at least one flared portion, at least one upper link, a latch bracket, a trip plate, a fork, at least one lower link assembly further comprising a tension spring, at least one knob to switch a circuit breaker ON or OFF; and a flipping mechanism to control a latching and a de-latching in the circuit breaker.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.

Figure 1 illustrates isometric view of the breaker is shown, in accordance with an embodiment of the present subject matter.

Figure 2 illustrates an exploded view of partial breaker is shown, in accordance with an embodiment of the present subject matter.

Figure 3 illustrates an exploded view of mechanical system is shown, in accordance with an embodiment of the present subject matter.

Figure 4 illustrates a Latch link is shown, in accordance with an embodiment of the present subject matter.

Figure 5 illustrates a trip system in mechanical system latched position is shown, in accordance with an embodiment of the present subject matter.

Figure 6 illustrates a trip system in mechanical system De-Latched position is shown, in accordance with an embodiment of the present subject matter.

Figure 7 illustrates a trip plate is shown, in accordance with an embodiment of the present subject matter.

Figure 8 illustrates a mounting plate is shown, in accordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION

Preferred embodiments of the present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.

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, the present invention is a mechanism to hold a trip plate in a position to avoid an overriding of latch bracket.

Construction of the connector assembly of the present invention is explained with reference to the accompanying figures.

List of components used in the figure are:

1. Mounting Plate (1, 7)
2. Latch link (2)
3. Upper Link (3)
4. Flared portion (4, 5)
5. Rear end flaring (6)
6. Trip Plates (8)
a. 8a.TP Latch Point (8a)
b. 8b. Hooker (8b)
7. Fork (9)
8. Assembly (10)
9. Pin (11)
10. Tension Spring (12)
11. Latch Bracket (13)
12. Lower links (14)
13. Knob (15)
14. Trip spring hook in 7 (16)
15. Full breaker (17)
16. Bottom housing (18)
17. Mechanism with current path (19)
18. Top cover assembly (20)

In one implementation a mechanism to hold a trip plate (8) in a position to avoid an overriding of latch bracket is disclosed. The mechanism comprises of at least one mounting plate (1, 7) with at least one rear end flaring (6). The mechanism further comprises of a latch link (2) with at least one flared portion (4, 5), at least one upper link (3), a latch bracket (13), a fork (9), at least one lower link (14) assembly (10) further comprising a tension spring (12), at least one knob (15) to switch a circuit breaker ON or OFF; and a flipping mechanism to control a latching and a de-latching in the circuit breaker.

In one implementation, the upper link (3) is coupled with the flared portion (4, 5) and the latch bracket (13) is coupled with the at least one rear end flaring (6). The at least one mounting plate (1, 7) is locked between the trip plate (8) and the fork (9) and the tension spring (12) at first end is hooked to the fork (9) using a pin (11). Further, the tension spring (12) at second end is hooked to the trip plate (8) and the at least one mounting plate (1, 7).

In one implementation the latching occurs when the latch link (2) presses the latch bracket (13), thereby pressing the tension spring (12) hooked between the latch bracket (13) and trip plate (8) which in turn pulls the trip plate (8). The de-latching occurs when the latch link (2) releases the latch bracket (13), thereby releasing the tension spring (12) hooked between the latch bracket (13) and trip plate (8) which in turn pushes the trip plate (8).

In one implementation, the current invention is used in the trip system of mechanical system has a trip plate (8), trip plate spring (Tension Spring) (12), Latch Bracket (13), Latch link (2), Mounting Frames- Left & right (1, 7), Fork (9), and a Knob (15). The latch link (2) has a flared portion in the front (4) by which it is secured to one side of the mounting plate (1). The upper link (3) is secured to the flared portion (5) of the latch link (20, which act as a pivot. The Latch bracket (13) is secured to the mounting plate by the flared projection (6) at the rear in it. The other mounting plate (7) is located and locked by the trip plate (8) and the fork (9). Now the lower link (14) assembly (10) along with the tension spring (12) (not shown) is hooked to the fork (9) by carefully locating the pin (11) in the assembly (9) in the upper link slot.

The Trip Spring (tension spring) (12) is hooked to the trip plate (8) and mounting plate (1, 7).

Now the mechanism is in trip condition, when it resets, the latch link (2) is latched to the latch bracket (13) and its freedom is restricted by the trip plate (8). The normal force on trip plate (8) by (13) is in the 1st quadrant with respect to trip plate (8) pivot. The Tension spring (12) stabilizes the trip plate (8) in its position. The Trip plate (8) has stoppers built in the mounting plate (1, 7) at its extremes – latched condition and de-latched condition. After this the mechanism will be able to switch ON and OFF, thus results in making and breaking the current. In abnormal conditions the trip system receives the signal and functions as said above.

In one implementation, the arrangement disclosed above have the flipping mechanism built in it, which controls the latching and de-latching. The latching occurs when the latch link (2) is presses the latch bracket (13) the biasing spring hooked between the latch bracket (13) and trip plate (8) which in turn pulls the trip plate (8). Thus the trip spring (12) hooked at the trip plate (8) on the hooker (as shown in figure 7) travels anticlockwise with respect to the other end hooked on mounting plate (1) (as shown in figure 8) thus crossing the trip plate (8) pivot. This phenomenon is called positive flipping action. This action helps us in controlling the trip force, avoids nuisance tripping, as shown in figure 5.

The trip plate (8) may receive the signal from the release in the form of force with travel. This force moves the trip plate (8) clockwise with respect to its pivot. This clockwise movement of the trip plate moves the spring point where it is hooked at the trip plate (8) in the hooker (as shown in figure 7). After a certain travel it crosses the trip plate (8) pivot resulting in opening the circuit or having tripping action in the mechanism by de-latching the latch bracket (13). The phenomena helps in de-latching the latch bracket (13) in the trip system is called negative flipping. This helps in having the flexibility over the travel of trip plate (8) required to trip, as shown in figure 6.

The trip plate (8) is moved or rotated by the release either magnetic, thermal or internal accessories such as UV, Shunt or FSD, the latch point (latch bracket latched by trip plate) crosses the spring line such that it de-latch the latch bracket and results in tripping of the breaker. This above mechanism gives the flexibility in controlling the travel required by the release.

The disclosed invention may be used to trip the breaker with the help of accessories, thermal tripping, magnetic tripping during abnormal current flow in the circuit breaker and also manually for purposes of maintenance and checks whenever needed.

In one implementation, the proposed mechanism may be the improved feature of existing product. The improvement may be in the trip plate (8) that latches the latch bracket (13) and an integrator, the part of trip system which receives the trip signal from various elements. The latch bracket (13) may latch the latch link (2). The mounting plate (1, 7) may be a structure or a fixed frame in the system. Further, the trip system may have a trip spring (12).

In one implementation, the trip spring (tension spring) (12) may be hooked to the trip plate (8) and mounting plate (1, 7). The mechanism may be in trip condition, when it resets, and the latch link (2) may be latched to the latch bracket (13) and the freedom may be restricted by the trip plate (8). The normal force on trip plate (8) by the latch bracket (13) may be in the 1st quadrant with respect to the trip plate (8) pivots. The Tension spring (12) may stabilize the trip plate (8) in its position. The trip plate (8) may have the stoppers built in the mounting plate (1, 7) at its extremes are in latched condition and de-latched condition.

The above arrangement may have the flipping mechanism built in it, which controls the latching and de-latching of the entire mechanical system in the circuit breaker. The above mechanism eases the trip system design and also eliminates the nuisance tripping by keeping the centre of gravity of the trip plate below the spring line.

After this the mechanism will be able to switch ON and OFF, thus results in making and breaking the current. In abnormal conditions the trip system receives the signal and functions as said above.

Referring now to figure 1 illustrates an isometric view of the breaker is shown, in accordance with an embodiment of the present subject matter. The full breaker (17) is shown as an exemplary embodiment of the present invention.

Referring now to figure 2 illustrates an exploded view of partial breaker is shown, in accordance with an embodiment of the present subject matter. The top cover assembly (20), the mechanism with current path (19) and the bottom housing of the circuit breaker is shown as an exemplary embodiment of the present invention.

Referring now to figure 3 illustrates an exploded view of mechanical system is shown, in accordance with an embodiment of the present subject matter. In one implementation, the trip plate (8), the trip plate spring (Tension Spring) (12), the Latch Bracket (13), the Latch link (2), the Mounting Frames- Left & right (1, 7), the Fork (9), and the Knob (15). The latch link (2) has a flared portion in the front (4) by which it is secured to one side of the mounting plate (1). The upper link (3) is secured to the flared portion (5) of the latch link (20, which act as a pivot. The Latch bracket (13) is secured to the mounting plate by the flared projection (6) at the rear in it. The other mounting plate (7) is located and locked by the trip plate (8) and the fork (9). Now the lower link (14) assembly (10) along with the tension spring (12) (not shown) is hooked to the fork (9) by carefully locating the pin (11) in the assembly (9) in the upper link slot.

The Trip Spring (tension spring) (12) is hooked to the trip plate (8) and mounting plate (1, 7).

Referring now to figure 4 illustrates a Latch link is shown, in accordance with an embodiment of the present subject matter. The flared portion (4, 5) is shown as an exemplary embodiment of the present invention.

Referring now to figure 5 illustrates a trip system in mechanical system latched position is shown, in accordance with an embodiment of the present subject matter. The tension spring (12) is shown as an exemplary embodiment of the present invention.

Referring now to figure 6 illustrates a trip system in mechanical system De-Latched position is shown, in accordance with an embodiment of the present subject matter.

Referring now to figure 7 illustrates a trip plate is shown, in accordance with an embodiment of the present subject matter. The TP latch point (8a) and the hooker (8b) are shown, in accordance with an embodiment of the present subject matter.

Referring now to figure 8 illustrates a mounting plate is shown, in accordance with an embodiment of the present subject matter. The trip pin hook (16) in mounting plate (7) is shown, in accordance with an embodiment of the present subject matter.

Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features:

One feature of the present invention is that, a stable latching is provided. This avoids the nuisance tripping.

Another feature of the present invention is that, the proposed mechanism is without a major change in the existing trip system

Another feature of the present invention is that, the proposed mechanism provides flexibility in tripping parameters such as force and travel (variable non tripping point).

Yet another feature of the invention is that, the proposed mechanism provides the flexibility in providing from bottom trip to top trip.

Still another feature of the present invention is that, the proposed mechanism provides an eases of the design for the trip arrangement.

Apart from the above disclosed features of the invention, the proposed mechanism is novel with respect to the flip mechanism in the trip system that is the positive flipping and the negative flipping.

Although implementations for the mechanism to hold a trip plate in a position to avoid an overriding of latch bracket have been described in language specific to structural features and/or the methods, it is to be understood that the appended claims are not necessarily limited to the specific features or methods described. Rather, the specific features are disclosed as examples of, the mechanism to hold a trip plate in a position to avoid an overriding of latch bracket.

It is intended that the disclosure and examples above be considered as exemplary only, with a true scope and spirit of disclosed embodiments being indicated by the following claims.