Description:

TECHNICAL FIELD
The present invention relates to the field of auto operation of a circuit breaker in general, more particularly to a door sensor feature for an actuating mechanism for the circuit breaker.

BACKGROUND OF THE INVENTION
Electrical operating mechanism (also referred as “EOM”) is used to drive molded case circuit breaker (MCCB) from a remote location through electrical input. EOM can be of two main types, direct drive operator and stored energy operator. In case of direct drive operator, motor energy is used in both ways of closing and opening the MCCB.
In case of stored energy operator, the motor energy is used in the direction of ON-OFF movement, which means opening of MCCB, in which the spring assembled in the system is charged and allowed to store energy through various mechanical means. The stored energy is discharged, during the OFF-ON motion, which means closing of MCCB contacts. Stored energy operator has two modes of operation that are manual and auto. Manual mode consists of a charging unit and a handle attached to it, so that a cranking system provided onto the handle allows customer to drive the MCCB from ON-OFF and a manual ON button allowing the unit to discharge the energized spring through various linkages mechanically connected. Auto mode consists of a motor charging the spring and driving the unit from ON-OFF and input from remote location discharges the energized spring through mechanical linkages connected below. MCCB being the governing element, with preset boundary conditions and constraints, Stored Energy Electrically Operated Mechanism (SE-EOM) must perform primary, secondary, and tertiary functions in a determined manner.
However, present SE-EOM lacks a feature in them, which can be used as a sensor to detect the position of the panel door. When the panel door is open, Motor operator (MO) cannot be operated with electrical input as the door sensor breaks the electronic circuit. This ensures the safety of the personnel operating the electrical equipment and prevents the personnel to operate the MO with electrical input when panel door is open which can create a possibility of an electrical hazard.
Reference is made to US7019229B1 disclosing a door interlock assembly and draw-out circuit breaker assembly employing the same. The draw-out circuit breaker is housed within an enclosure including a door and includes a poleshaft operable between first and second positions corresponding to separable contacts being opened and closed, respectively. The door interlock assembly includes a pivot member coupled to the poleshaft and a door latch interconnected to the pivot member by a linkage, such as a threaded drive rod. The door latch pivots such that a first end thereof engages and locks the door of the enclosure when the poleshaft moves to the second position.
Reference is made to US20170063050A1 disclosing a mechanical door interlock device for protecting power electrical switching apparatus and users. The mechanical switch-door interlock assembly includes a mounting assembly and an actuator assembly. The actuator assembly includes a body, a door sensor, an operating mechanism handle actuator, and a number of sliding coupling components. The actuator assembly body is slidably coupled to the mounting assembly. The actuator assembly body moves between a first position, wherein the operating mechanism handle actuator does not operatively engage the operating mechanism handle, and a second position, wherein the operating mechanism handle actuator operatively engages the operating mechanism handle and moves the operating mechanism handle to the second position. When a door is in a first position, the door operatively engages the door sensor and moves the actuator assembly body to the first position. When the door is in the second position, the door does not operatively engage the door sensor allowing the actuator assembly body to move into the second position.
Thus, in view of the prior art, there is a need of an added feature inside the SE-EOM mechanism to accomplish this door sensing feature for safety purpose. Feature also has a defeat mechanism to allows the personnel to operate the MO with electrical input when the panel door is open.

SUMMARY OF THE INVENTION
The following disclosure 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.

The main object of present invention is to address and remove all the above limitations.

An aspect of the present disclosure pertains to an actuating mechanism for a circuit breaker. The electrically operating mechanism includes a motor, an epicyclic gear assembly operatively configured with a motor shaft of the motor such that the rotation of motor shaft facilitates rotation of the epicyclic gear assembly that facilitates the rotation of drive shaft. The drive shaft may be operatively configured with a rack, and the rack may be configured to move linearly corresponding to the rotation of the drive shaft to stretch one or more springs of the circuit breaker for facilitating the charging operation.

According to an exemplary implementation, an actuating mechanism for a moulded case circuit breaker (MCCB) comprising: a Stored Energy Electrically Operated Mechanism (SE-EOM) comprising a motor, an epicyclic gear assembly operatively coupled with a motor shaft of the motor such that the rotation of motor shaft facilitates rotation of the epicyclic gear assembly to facilitate a rotation of a drive shaft, said SE-EOM is configured to detect a postion of a panel door and a Motor Operator MO is mounted on the MCCB, and adapted to operate the MCCB in ON, OFF and RESET modes, on receiving electric input, based on the position of the panel door.

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 ACCOMPANYING DRAWINGS
The above and other aspects, features and advantages of the embodiments of the present disclosure will be more apparent in the following description taken in conjunction with the accompanying drawings, in which:

Figure 1 illustrates an assembly of door sensor (1) on a mid-plate (5) when a panel door (8) is in closed condition, according to embodiments of the present invention.

Figure 2 illustrates an assembly when the panel door is in open condition where a microswitch (4) is not actuated (NO), according to embodiments of the present invention.

Figure 3 illustrates a microswitch and its actuator (6) which completes the electronic circuit when actuated, according to embodiments of the present invention.

Figure 4 illustrates a door sensor part which contains a dwell feature (7) that actuates the microswitch even when there is dimension variation of ± 5 mm in the closing position of panel door, according to embodiments of the present invention.
Figures 5 and 6 illustrate a sectional view of door sensor when the panel door is in closed and open condition respectively, according to embodiments of the present invention.

Figure 7 illustrates operating MO with electrical input when the panel door is in open condition, according to an embodiment of the present invention.

Figure 8 illustrates a perspective view of the door sensor safety feature for motor operated mechanism for a MCCB, according to an embodiment of the present invention.

Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may not have 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 PRESENT INVENTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure 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 various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be 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 present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure 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. Thus, for example, a reference to “a component surface” includes a reference to one or more of such surfaces.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments belong. Further, the meaning of terms or words used in the specification and the claims should not be limited to the literal or commonly employed sense but should be construed in accordance with the spirit of the disclosure to most properly describe the present disclosure.

The present disclosure will now be described more fully with reference to the accompanying drawings, in which various embodiments of the present disclosure are shown. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the various embodiments set forth herein, rather, these various embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the present disclosure. Furthermore, a detailed description of other parts will not be provided not to make the present disclosure unclear. Like reference numerals in the drawings refer to like elements throughout.

According to an embodiment, the present disclosure pertains to an actuating mechanism for a circuit breaker. The electrically operating mechanism (EOM) includes a motor, an epicyclic gear assembly operatively configured with a motor shaft of the motor such that the rotation of motor shaft facilitates rotation of the epicyclic gear assembly that facilitates the rotation of drive shaft. In an aspect, the drive shaft may be operatively configured with a rack, and the rack may be configured to move linearly corresponding to the rotation of the drive shaft to stretch one or more springs of the circuit breaker for facilitating the charging operation, which happens only when the panel door (8) is closed and microswitch (4) is actuated.

Charging operation of motor operator happens only when the panel door (8) is closed and microswitch (4) is actuated. During charging operation, motor shaft starts rotating and the motor gear which is mounted on the motor shaft also starts rotating. All gearing mechanism including the epicyclic gear train rotates during charging operation.

When motor gets supply, it starts rotating with the motor gear, which is assembled on the motor shaft. As illustrated in Figure 8, all compound gears and epicyclic gear train (assembly) starts rotating because all gears are linked with each other. After epicyclic gear train movement, the main shaft starts rotating causing pinion rotation and the rack travels linearly till charging condition. Drive shaft is the main shaft on which the pinion is fixed and motor shaft is the one on which the motor gear is attached. Rack (13) shown in fig 8.

The electronic circuit of the mechanism comprises a PCB, the Motor, a Solenoid and the microswitch.

When Motor operator (9) is mounted on MCCB, operation of the MCCB (On, off, Reset) happens through motor operator. The motor operator (9) operates on electric input. For electric input execution, the microswitch (4) needs to be actuated.

There can be two possible scenarios:
According to exemplary implementation, when the panel door (8) is in closed condition, a door sensor (1) will slide inside and actuate the microswitch (4). In that case, when charging operation command is given to the motor operator (9) for switching OFF the MCCB, the command will be executed and the MCCB will be switched OFF.

According to exemplary implementation, when the panel door (8) is in open condition, the door sensor (1) will come outside due to spring action and the microswitch (4) will not be in actuated condion. In this case, when charging operation command is given to the motor operator (9), command will not be executed.

The door sensor features is not in other motor operator products which we developed.The concepts which is used to actuate the microswitch through opening and closing position makes it inventive.

Figure 1 shows an assembly of a door sensor (1) on a mid-plate (5) when the panel door (8) is in closed condition (Position 2). Figure 2 shows the assembly when the panel door is in open condition (Position 1), where the microswitch (4) is not actuated (NO). The door sensor is spring (3) loaded such that it returns to position 1 as shown in Figure 2. Figure 3 shows the microswitch (4) and its actuator (6) which completes the electronic circuit when actuated. Figure 4 shows the door sensor (1) part which contains a dwell feature (7) that actuates the microswitch even when there is dimension variation of ± 5 mm in the closing position of panel door. Figure 5 and figure 6 shows the sectional view of door sensor when the panel door is in closed and open condition respectively. To operate MO with electrical input when the panel door is in open condition, a cap (10) is placed on the given slot to complete the electronic circuit as shown in figure 7.

Panel door closed condition:
When the panel door (8) is in closed condition, the door hits the door sensor (1) which actuates the microswitch (4) to NC (normally closed) condition. This completes the electronic circuit thereby allowing operation of MO (9) with electrical input.

Panel door open condition:
When the panel door (8) is in open condition, the door sensor (1) is brought back to position 1 by the spring action (3) as shown in figure 6. The microswitch (4) becomes NO (normally open) condition which leaves the electronic circuit incomplete. Hence MO (9) cannot be operated with electrical input when the panel door (8) is in open condition.

Defeat feature:
When MO (9) has to be operated with electrical input in panel door (8) open condition, a cap (10) is placed in the given slot (figure 7) which holds the door sensor (1) in position 2 which actuates the microswitch (4) to NC condition thus completing the electronic circuit.

Therefore, when the panel door (8) is open, MO (9) cannot be operated with electrical input as the door sensor (1) breaks the electronic circuit. This ensures the safety of the personnel operating the electrical equipment and prevents the personnel to operate the MO with electrical input when panel door is open which can create a possibility of an electrical hazard.

Some of the non-limiting advantages of the door sensor safety feature for motor operated mechanism for a circuit breaker are:
1. MO cannot be operated with electrical input when the panel door is open.
2. MO can be operated with electrical input when the panel door is closed.
3. Door sensor safety feature design.

Although an actuating mechanism of a circuit breaker has been described in language specific to structural features, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific methods or devices described herein. Rather, the specific features are disclosed as examples of implementations of the actuating mechanism of a circuit breaker.

Reference numeral Component Name
1 Door sensor
2 Spring pin
3 Spring
4 Microswitch
5 Mid-plate
6 Microswitch actuator
7 Door sensor dwell
8 Panel door
9 Motor operator (MO)
10 Cap
11 Motor
12 Epicyclic gear train
13 Rack
, Claims:
1. An actuating mechanism for a moulded case circuit breaker (MCCB) comprising:
a Stored Energy Electrically Operated Mechanism (SE-EOM) comprising a motor, an epicyclic gear assembly operatively coupled with a motor shaft of the motor such that the rotation of motor shaft facilitates rotation of the epicyclic gear assembly to facilitate a rotation of a drive shaft, said SE-EOM is configured to detect a postion of a panel door (8) and a Motor Operator MO (9) is mounted on the MCCB, and adapted to operate the MCCB in ON, OFF and RESET modes, on receiving electric input, based on the position of the panel door.

2. The actuating mechanism as claimed in claim 1, wherein the mechanism comprises a compound gear arrangement coupled with the epicyclic gear assembly, so as to rotate simultaneously.

3. The actuating mechanism as claimed in claim 1, wherein when the panel door (8) is closed and the microswitch (4) is actuated, the drive shaft is operatively coupled with a rack of a rack-pinion assembly, said rack is adapted to move linearly corresponding to the rotation of the drive shaft, to stretch one or more springs of the circuit breaker for facilitating a charging operation.

4. The actuating mechanism as claimed in claim 1, wherein during charging operation, a motor gear arrangement assembled on the motor shaft rotates simultaneously with the compound gear arrangement coupled with the epicyclic gear assembly, and after epicyclic gear assembly movement, the drive shaft starts rotating causing a pinion rotation and the rack travels linearly till charging condition, wherein the drive shaft is the shaft on which the pinion is fixed and the motor shaft is the one on which the motor gear is attached.

5. The actuating mechanism as claimed in claim 1, wherein when the SE-EOM is configured to detect the panel door to be open, the Motor operator (MO) cannot be operated with electrical input.

6. The actuating mechanism as claimed in claim 1, wherein when the panel door (8) is in closed condition, a door sensor (1) is adapted to slide inside and actuate the microswitch (4), and on receiving charging operation command for switching OFF the MCCB, the MO is configured to switch off the the MCCB.

7. The actuating mechanism as claimed in claim 1, wherein when the panel door (8) is in open condition, the door sensor (1) is adapted to come outside due to spring action and the microswitch (4) is in non-actuated condion, and on receiving charging operation command, the motor operator (9) is unable to perform such command.

8. The actuating mechanism as claimed in claim 1, wherein a cap (10) is placed in a given slot which holds the door sensor (1) in closed panel door position, the MO (9) is adapted to operate with electrical input in panel door (8) open condition, thereby actuating the microswitch (4) to NC (Normally closed) condition to complete the electronic circuit.

9. The actuating mechanism as claimed in claim 6, wherein the door sensor is a spring (3) loaded sensor having a soring pin (2), and adapted to return to its predefined position whne the panel door is in open condition, and the door sensor (1) has a dwell feature (7) to actuate the microswitch (4) even when there is dimension variation of ± 5 mm in the closing position of panel door.