Description:TECHNICAL FIELD
[0001] The present disclosure relates, in general, to the flux shift device, and more specifically, relates to a calibration of holding force in the flux shift device.

BACKGROUND
[0002] Flux shift devices are used in molded case circuit breakers with electronic fault sensing units. The electronic sensing unit sends the trip command to the flux shift device on identifying the fault. The flux shift device, in turn, converts the received electric signal to mechanical energy and initiates the interruption of fault by molded case circuit breaker. A flux shift device is an energy storage device with a magnetic circuit made of soft ferromagnetic material which is under continuous excitation by the permanent magnet to generate magnetic forces to overcome spring force. An electromagnetic source mounted in the same device generates opposing flux to the permanent magnet flux. As the main flux weakens due to the trigger of opposing flux by an electromagnet, the stored energy of the mechanism is released which in turn activates the mechanism of the circuit breaker.
[0003] The contemporary invention addresses a significant challenge faced during the manufacturing of devices that rely on holding force, particularly flux shift devices. Despite the designed holding force being intended to remain constant, practical production processes result in variations, creating a spectrum of holding force values around the nominal value. This variability leads to device rejections when the holding force falls below a defined threshold value.
[0004] Therefore, it is desired to mitigate nonconformance and minimize rejections, shortcomings, and limitations associated with existing solutions, and develop a feature that dynamically adjusts the spring force, effectively compensating for the magnetic force loss caused by process variations. Consequently, the holding force is brought above the critical threshold, ensuring better conformity and enhancing the overall reliability of the devices.

OBJECTS OF THE PRESENT DISCLOSURE
[0005] An object of the present disclosure relates, in general, to the flux shift device, and more specifically, relates to a calibration of holding force in the flux shift device.
[0006] Another object of the present disclosure is to provide a device that adjusts the holding force of the device using the calibration nut that allows for precise calibration during assembly. This ensures that the device operates within the desired force range, enhancing its performance and reliability.
[0007] Another object of the present disclosure is to provide a device that by incorporating the adjustable holding force feature, the device reduces the likelihood of rejections during production. If the force values are below the threshold level, they can be calibrated to meet the required specifications, leading to higher production yield and reduced waste.
[0008] Another object of the present disclosure is to provide a device that provides flexibility in tailoring the holding force as per specific application requirements. Different applications may demand varying force levels, and this device can be easily calibrated accordingly.
[0009] Another object of the present disclosure is to provide a device that saves costs associated with producing rejected units.
[0010] Another object of the present disclosure is to provide a device that provides a reliable tripping mechanism, where the tripping mechanism is more reliable and consistent. This ensures that the device functions as intended during overload or fault conditions, improving overall safety and performance.
[0011] Another object of the present disclosure is to provide a device that provides easy adjustment of the holding force. It can be easily rotated to achieve the desired force level, making it user-friendly and efficient.
[0012] Yet another object of the present disclosure is to provide a device that enhances the versatility of the flux shift device, making it suitable for a wider range of applications and operating conditions.

SUMMARY
[0013] The present disclosure relates in general, to the flux shift device, and more specifically, relates to a calibration of holding force in the flux shift device. The main objective of the present disclosure is to overcome the drawback, limitations, and shortcomings of the existing device and solution, by providing a flux shift device that is capable of adjusting its holding force and varying the output force of the tripping mechanism during assembly. This is achieved by changing the stored energy of the spring in the device.
[0014] The present invention addresses the crucial need for a flux shift device with stable performance under harsh conditions, such as high temperature, shock and vibration environments. The high holding force margin of the device is essential for ensuring its reliable performance. Conversely, a low holding force could lead to unintended tripping of the device, which is undesirable for customers.
[0015] The proposed disclosure proposes an approach to achieve the desired holding force margin of the device. The holding force is determined by the differential between the magnetic force generated by the device and the spring force. To enable customization of the holding force, the disclosed invention introduces the option of varying the spring force. By adjusting the spring force, the device's holding force can be fine-tuned to suit specific application requirements, ensuring optimal performance even in challenging environments. This capability enhances the device's reliability, making it an attractive solution for various industrial and commercial applications.
[0016] Further, the present disclosure provides a versatile and reliable flux shift device capable of maintaining stable performance in harsh conditions, offering customers the ability to tailor the holding force according to their specific needs. This innovation is poised to have a significant impact on various industries where precise control and dependable operation are paramount.
[0017] The flux shift device utilizes a combination of components, including a permanent magnet, fixed and movable cores, and a compression spring. The movable core is connected to a calibration nut and arrester, enabling post-assembly calibration. By rotating the calibration nut, the holding force of the device can be increased or decreased, allowing for precise adjustment and stable performance. The stored energy in the spring is released through the triggering of an electromagnetic coil, enabling variable output force for the tripping mechanism. This innovation ensures a flexible and efficient flux shift device with controllable holding and tripping forces.
[0018] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The following drawings form part of the present specification and are included to further illustrate aspects of the present disclosure. The disclosure may be better understood by reference to the drawings in combination with the detailed description of the specific embodiments presented herein.
[0020] FIG. 1A illustrates an exemplary schematic view of the flux shift device, in accordance with an embodiment of the present disclosure.
[0021] FIG. 1B illustrates an exemplary view of differential force between the magnetic force from the permanent magnet and the compression spring force, in accordance with an embodiment of the present disclosure.
[0022] FIG. 1C illustrates an exemplary schematic view of the open position with the spring force of the flux shift device, in accordance with an embodiment of the present disclosure.
[0023] FIG. 1D illustrates an exemplary schematic view of the closed position with the spring force of the flux shift device, in accordance with an embodiment of the present disclosure.
[0024] FIG. 2 illustrates an exemplary flow chart of operating the flux shift device, in accordance with an embodiment of the present disclosure.
[0025] FIG. 3 illustrates an exemplary graphical view of the force levels of the flux shift device, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0026] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0027] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0028] The present disclosure relates, to the flux shift device, and more specifically, relates to a system and method for calibration of holding force in the flux shift device.
[0029] The flux shift device can include a fixed core serving as a stationary component within a magnetic circuit to complete the magnetic flux path during device operation. The permanent magnet generates a constant magnetic field to power the magnetic circuit and hold a movable core in its default closed position, wherein the movable core is capable of moving within the magnetic circuit and coupled to the fixed core by the magnetic field of the permanent magnet. The compression spring is assembled with the movable core to store energy proportional to the deflection length during device operation. The electromagnetic coil wound around the core, generating an electromagnetic field upon the flow of current, interacting with the magnetic field of the permanent magnet to trigger the release of stored energy from the compression spring and activate the device. An arrester serves as a fixed reference point within the device providing an unchanging position for a calibration nut and the compression spring, wherein the calibration nut is adjustably threaded onto the arrester to enable variations in the force of the compression spring after the device assembly, thereby adjusting the holding force of the device.
[0030] Further, the device can include a cover providing mechanical support and protection to the internal components of the device. The compression spring is mounted between the cover and the calibration nut that is movable between the upward direction and downward direction respectively. In the downward direction of the calibration nut, the compression spring assembled with the movable core stores energy proportionate to its deflection length when the device is in the partially open state; wherein, in the upward direction of the calibration nut, the movable core remains connected to the compression spring to retain the energy stored during the fully closed state of the device.
[0031] In an aspect, the calibration nut is rotated towards the arrester so as to form the closed state to increase the holding force of the device without affecting the movable core travel of the device. The calibration nut is rotated in a clockwise direction to increase the holding force after the device is tripped. In another aspect, the calibration nut is rotated away from the arrester so as to form an open state to decrease the holding force of the device without affecting the movable core travel of the device. The calibration nut is rotated in an anti-clockwise direction to decrease the holding force when the device remains in the state without tripping. The movement of the calibration nut either away or towards the arrester does not affect the movable core travel of the flux shift device, maintaining the same movable core travel during device operation. The adjustable calibration nut offers flexibility to fine-tune the holding force, ensuring stable and reliable performance of the device in various applications and environments. Moreover, the device is verified for de-latching by exciting the electromagnetic coil at a specified voltage after assembly. The present disclosure can be described in enabling detail in the following examples, which may represent more than one embodiment of the present disclosure.
[0032] The advantages achieved by the device of the present disclosure can be clear from the embodiments provided herein. The device provides an adjustable holding force feature in the flux shift device offers significant advantages, including improved calibration, higher production yield, cost-effectiveness, and enhanced reliability. These benefits contribute to the overall efficiency and effectiveness of the device in various applications, making it a valuable innovation in the field of flux shift technology. The description of terms and features related to the present disclosure shall be clear from the embodiments that are illustrated and described; however, the invention is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents of the embodiments are possible within the scope of the present disclosure. Additionally, the invention can include other embodiments that are within the scope of the claims but are not described in detail with respect to the following description.
[0033] FIG. 1A illustrates an exemplary schematic view of flux shift device, in accordance with an embodiment of the present disclosure.
[0034] Referring to FIG. 1A, flux shift device 100 is disclosed. The device 100 can include fixed core 102, permanent magnet 104, movable core or plunger 106, compression spring 108, electromagnetic coil 110, arrester 112, calibration nut 114, and cover 116.
[0035] The fixed core 102 is a stationary component within the magnetic circuit. It provides a stable base for the other components and plays a crucial role in completing the magnetic flux path during device operation. The permanent magnet 104 is a crucial element of the magnetic circuit. It generates a constant magnetic field that powers the magnetic circuit of the device. This constant magnetic field is responsible for holding the movable core 106 or plunger in its default closed position. The movable core 106 is a component that can move within the device's magnetic circuit. It is attracted to the fixed core 102 by the magnetic field of the permanent magnet 104, leading to the default closed condition of the magnetic circuit.
[0036] The compression spring 108 is a critical energy-storing element in the device. It is assembled with the movable core 106 and compressed during the device's operation. This compression results in the storage of energy proportional to the deflection length of the spring, which is released later through the triggering of the electromagnetic coil 110.
[0037] The electromagnetic coil 110 is a coil of wire wound around the core. When current flows through the coil, it generates an electromagnetic field, which interacts with the permanent magnet's magnetic field. This interaction causes the movable core 106 to move, releasing the stored energy from the compression spring 108 and triggering the device's output.
[0038] The arrester 112 is a component that plays a role in the invention's calibration mechanism. It is fixed in place and serves as a reference point for the calibration nut's movement. The calibration nut 114 is threaded onto the arrester 112. The calibration nut 114 is an adjustable component that can be moved up and down along the arrester 112 using a threading mechanism. Its movement allows for adjusting the force of the compression spring 108 after the device assembly. By rotating the calibration nut 114 towards or away from the arrester 112, the holding force of the device can be increased or decreased, respectively. The cover 116 is a protective casing or enclosure that houses the components of the device. It provides mechanical support and safeguards the internal components from external elements.
[0039] In an implementation, the device 100 can include a magnetic circuit which consists of fixed core 102, the permanent magnet 104 and the movable core or plunger 106. The magnetic circuit is always powered by the permanent magnet 104, so the default position of the device is magnetic circuit in closed condition. While the magnetic circuit is in closed condition, the movable core 106 is assembled with the compression spring 108, as a result, the compression spring 108 may store energy proportional to the deflection length. The output energy of the device is stored energy of the spring which is released through the triggering of the electromagnetic coil 110.
[0040] The present disclosure pertaining to the stored energy of the device, the components involved are compression spring 108, calibration nut 114 and arrester 112. The arrester 112 and the calibration nut 114 are assembled to each other by threading mechanism. The threading mechanism allows the calibration nut 114 to move up and down as against the fixed arrester 112. The device’s movable core assembly is connected to the components and the spring is mounted between the cover 116 and calibration nut 114. Current construction offers the scope to vary the force of the compression spring 108 after the assembly of device 100. As shown in the FIG. 1B the differential force between the magnetic and spring force is the holding force which plays a predominant role in the stable performance of the device, and is calibrated using the feature.
[0041] The challenge of maintaining the plunger travel and provision of calibrating the device after assembly by rotating the calibration nut 114 is disclosed. Rotating the calibration nut 114 towards the arrester 112 can increase the holding force of the FSD 100 and moving the calibration nut 114 away from the arrester 112 can decrease the holding force of the MCCB. While the calibration nut 114 is moved either away or towards the arrester 112, the plunger travel of the FSD remains the same. Plunger travel is critical for tripping the mechanism of the moulded case circuit breaker whereas the lower travel may lead to failure to trip the mechanism of the moulded case circuit breaker.
[0042] After the assembly as explained in the flow chart shown in FIG.2 device 100 may be verified for de-latching by exciting the coils at the specified voltage. Then, the device is measured with the holding force value, if the force turns out more than the threshold value, the device 100 may be qualified. On the other hand, if the force value falls short of the threshold, the device may go through the calibration method where calibration nut 114 may be rotated in the clockwise direction to achieve the required holding force. If the force value is so high that the device is unable to trip, the device may go through the calibration method where calibration nut 114 may be rotated in an anti-clockwise direction to achieve the required holding force and tripping. Further, the device 100 may go through the force measurement step if the force is on the lower side and the process may repeat till it reaches the tripping function and required holding force value.
[0043] FIG. 1B illustrates an exemplary view of differential force between the magnetic force from the permanent magnet and the compression spring force, in accordance with an embodiment of the present disclosure. The differential force between the magnetic force from the permanent magnet 104 and the compression spring force is known as the holding force. This holding force is crucial for keeping the device 100 in its default closed condition, ensuring proper operation.
[0044] The calibration nut 114 allows for post-assembly calibration of the device 100. By rotating the calibration nut 114 towards the arrester 112, the holding force of the flux shift device (FSD) can be increased. Conversely, rotating the calibration nut 114 away from the arrester 112 reduces the holding force of the moulded case circuit breaker (MCCB). This adjustability of the holding force enables fine-tuning and customization for different applications, resulting in increased production yield with reduced rejections.
[0045] While the calibration nut 114 is adjusted to modify the holding force, the plunger 106 travel of the flux shift device remains constant. The plunger 106 travel is the critical distance that the movable core travels within the magnetic circuit during device operation. Maintaining a consistent plunger travel is essential for the reliable tripping mechanism of the moulded case circuit breaker (MCCB). A lower plunger travel could lead to failure in tripping during overload or fault conditions, compromising circuit protection.
[0046] FIG. 1C illustrates an exemplary schematic view of the open position with the spring force of the flux shift device, in accordance with an embodiment of the present disclosure. The device's open position refers to a state where the magnetic circuit is disengaged or not fully closed. In this configuration, the magnetic circuit consists of the fixed core 102, the permanent magnet 104, and the movable core or plunger 106. The permanent magnet 104 continuously supplies power to the magnetic circuit, ensuring that the default position of the device is in a partially open state.
[0047] In the open position, the movable core 106 is assembled with the compression spring 108, which is situated between the cover 116 and the calibration nut 114. The compression spring 108 is designed to store energy proportionate to its deflection length, ensuring that the device can store potential energy when in this partially open configuration.
[0048] FIG. 1D illustrates an exemplary schematic view of the closed position with spring force of the flux shift device, in accordance with an embodiment of the present disclosure. FIG. 1D presents an exemplary schematic view of the closed position of the flux shift device, again following the embodiment of the present disclosure.
[0049] The closed position of the device signifies that the magnetic circuit is fully engaged or closed. The magnetic circuit comprises the same components as in FIG. 1C. The permanent magnet 104 continues to power the magnetic circuit, resulting in the default position of the device being in a fully closed state. As the magnetic circuit closes, the movable core 106 remains connected to the compression spring 108, and the spring retains the energy stored during the open position. The calibration nut 114 plays a crucial role in the device's closed position, as it is threaded and can be adjusted to modify the spring force within the device.
[0050] In FIG. 1C and FIG. 1D, there are force levels F3 and F2 which are the calibration limits of the device. F3 is the lower limit and the devices are assembled in this condition. When the force values are under threshold level, the calibration nut 114 is rotated gradually in upward direction to achieve the desired holding force.
[0051] Thus, the present invention overcomes the drawbacks, shortcomings, and limitations associated with existing solutions, and provides an adjustable holding force feature in the flux shift device offers significant advantages, including improved calibration, higher production yield, cost-effectiveness, and enhanced reliability. These benefits contribute to the overall efficiency and effectiveness of the device in various applications, making it a valuable innovation in the field of flux shift technology.
[0052] FIG. 2 illustrates exemplary flow chart of operating the flux shift device, in accordance with an embodiment of the present disclosure.
[0053] Referring to FIG.2, the method 200 includes at block 202, the magnetization of the device at the fully open position of the calibration nut 114. At block 204, the de-latching of the flux shift device through a voltage pulse. At block 206, determine if the device is tripping at the specified trip voltage. At block 208, if the device does not trip, proceed to calibration by rotating the calibration nut 114 in an anti-clockwise direction in steps.
[0054] At block 210, if the device trips, proceed to measurement of holding force. At block 212, determine if the holding force is above the threshold value. At block 214, if the holding force is above the threshold value, the device is qualified. At block 216, if the holding force is below the threshold value, proceed to calibration by rotating the calibration nut 114 in a clockwise direction in steps as needed until the required holding force is achieved. At block 218, proceed to measurement of holding force and continue the process.
[0055] At block 220, after the calibration adjustments, recheck determine if the holding force is above the threshold value. If the device now trips, the calibration is successful, and the device is qualified. If the device still does not trip or faces any other issues, further adjustments or inspections may be required.
[0056] The method provides a detailed calibration process to ensure the flux shift device meets the required holding force and tripping functionality. The calibration nut's rotational adjustments are utilized to optimize the holding force until the device conforms to the specified threshold values, ensuring reliable and stable performance. The final check confirms the calibrated device's proper functioning, qualifying it for use in the desired applications.
[0057] FIG. 3 illustrates an exemplary graphical view of the force levels of the flux shift device, in accordance with an embodiment of the present disclosure.
[0058] FIG. 3 represents the force levels, there are force levels F3 and F2 which are the calibration limits of the device. F3 is the lower limit and the devices are assembled in this condition. When the force values are under threshold level, the calibration nut 114 is rotated gradually in upward direction to achieve the desired holding force. Force levels are represented in the FIG. 3, calibration range is between F3 and F2 where F1 represents the de-latched position force of the device. F3 and F2 are achieved as shown in FIG. 3, by varying the compressed length of the spring.
[0059] It will be apparent to those skilled in the art that the device 100 of the disclosure may be provided using some or all of the mentioned features and components without departing from the scope of the present disclosure. While various embodiments of the present disclosure have been illustrated and described herein, it will be clear that the disclosure is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the disclosure, as described in the claims.

ADVANTAGES OF THE PRESENT INVENTION
[0060] The present invention provides a device that adjusts the holding force of the device using the calibration nut that allows for precise calibration during assembly. This ensures that the device operates within the desired force range, enhancing its performance and reliability.
[0061] The present invention provides a device that by incorporating the adjustable holding force feature, the device reduces the likelihood of rejections during production. If the force values are below the threshold level, they can be calibrated to meet the required specifications, leading to higher production yield and reduced waste.
[0062] The present invention provides a device that provides flexibility in tailoring the holding force as per specific application requirements. Different applications may demand varying force levels, and this device can be easily calibrated accordingly.
[0063] The present invention provides a device that saves costs associated with producing rejected units.
[0064] The present invention provides a device that provides a reliable tripping mechanism, where the tripping mechanism is more reliable and consistent. This ensures that the device functions as intended during overload or fault conditions, improving overall safety and performance.
[0065] The present invention provides a device that provides easy adjustment of the holding force. It can be easily rotated to achieve the desired force level, making it user-friendly and efficient.
[0066] The present invention provides a device that enhances the versatility of the flux shift device, making it suitable for a wider range of applications and operating conditions.
, Claims:1. A flux shift device (100), the device comprising:
a fixed core (102) serving as a stationary component within a magnetic circuit to complete the magnetic flux path during device operation;
a permanent magnet (104) generating a constant magnetic field to power the magnetic circuit and hold a movable core (106) in its default closed position, wherein the movable core (106) is capable of moving within the magnetic circuit and coupled to the fixed core (102) by the magnetic field of the permanent magnet (104);
a compression spring (108) assembled with the movable core (106) to store energy proportional to the deflection length during device operation;
an electromagnetic coil (110) wound around the core, generating an electromagnetic field upon the flow of current, interacting with the magnetic field of the permanent magnet (104) to trigger the release of stored energy from the compression spring (108) and activate the device; and
an arrester (112) serving as a fixed reference point within the device providing an unchanging position for a calibration nut (114) and the compression spring (108), wherein the calibration nut (114) adjustably threaded onto the arrester (112) to enable variations in the force of the compression spring (108) after the device assembly, thereby adjusting the holding force of the device.

2. The flux shift device as claimed in claim 1, wherein the device comprises a cover (116) providing mechanical support and protection to the internal components of the device.

3. The flux shift device as claimed in claim 1, wherein the compression spring (108) is mounted between the cover (116) and the calibration nut (114) that is movable in the upward direction and downward direction respectively, wherein at the downward direction of the calibration nut, the compression spring (108) assembled with the movable core (106) to store energy proportionate to its deflection length when the device is in the partially open state; and wherein, at the upward direction of the calibration nut, the movable core (106) remains connected to the compression spring (108) to retain the energy stored during the fully closed state of the device.

4. The flux shift device as claimed in claim 1, wherein the calibration nut (114) is rotated towards the arrester (112) so as to form the closed state to increase the holding force of the device without affecting the movable core (106) travel of the device.

5. The flux shift device as claimed in claim 1, wherein the calibration nut (114) is rotated away from the arrester (112) so as to form the open state to decrease the holding force of the device without affecting the movable core (106) travel of the device.

6. The flux shift device as claimed in claim 1, wherein the calibration nut (114) is rotated in a clockwise direction to increase the holding force after the device is tripped.

7. The flux shift device as claimed in claim 1, wherein the calibration nut (114) is rotated in an anti-clockwise direction to decrease the holding force, when the device remains in the state without tripping.

8. The flux shift device as claimed in claim 1, wherein movement of the calibration nut (114) either away or towards the arrester (112) does not affect the movable core (106) travel of the flux shift device, maintaining the same movable core (106) travel during device operation.

9. The flux shift device as claimed in claim 1, wherein the device is verified for de-latching by exciting the electromagnetic coil (110) at specified voltage after assembly.

10. The flux shift device as claimed in claim 1, wherein the adjustable calibration nut (114) offers flexibility to fine-tune the holding force, ensuring stable and reliable performance of the device in various applications and environments.