Target magnet mechanism for proximity switch

Abstract

A target magnet mechanism for a proximity switch. The target magnet mechanism includes a plurality of magnets arranged in an alternating magnetic pole configuration that forms a narrowing magnetic field with polarity reversals. A center magnet has a magnetic polarity opposite to that of the sensing magnet of the proximity switch. The flank magnets include magnetic poles that are opposite to the magnetic polarity of the center magnet and the same as the magnetic polarity of the sensing magnet. Configured in this way, the plurality of magnets trigger the proximity switch to an activated state by pulling on the magnetic field of the proximity switch via the opposite polarities of the center magnet and the sensing magnet. Additionally, the plurality of magnets release the proximity switch back to an unactivated state by pushing on the magnetic field of the proximity switch via the same polarities of the flank magnets and the sensing magnet.

Description

Technical Field

[0001] The present disclosure generally relates to magnetic proximity switches, and more particularly, to a target magnet mechanism for a proximity switch. Background Art

[0002] Magnetic proximity switches, also known as limit switches, are commonly used for linear position sensing. Generally, a magnetic proximity system typically includes a target and a sensor. In one example, as the target passes within a predetermined range of the sensor, the magnetic flux generated by the target (such as a target magnet) causes the switch to close.

[0003] Figure 1A and Figure 1B Depicted is a conventional proximity switch 10 disposed within a switch housing 12, which is operatively coupled to a rotary actuator 14 having a shaft 16. The switch housing 12 includes an opening through which the shaft 16 passes. The switch housing 12 houses the conventional proximity switch 10 and a target carrier 18 (such as a disk) having a target magnet 20 disposed thereon. The target carrier 18 also includes an opening for receiving the shaft 16 such that when the shaft 16 rotates, the target carrier 18 rotates. To set the proximity switch 10 to trigger at a particular rotational point of the actuator 14, the actuator 14 and thus the shaft 16 are rotated to that desired point. The proximity switch 10 is fixed; it does not move even when the shaft 16 moves.

[0004] When the shaft 16 rotates, the target carrier 18 rotates to move the target magnet 20 into the sensing region of the proximity switch 10. When the target magnet 20 moves into the sensing region of the proximity switch 10, the proximity switch 10 is attracted to the target magnet 20, causing the proximity switch 10 to change state.

[0005] More specifically, now referring to Figures 2 - 5 , the conventional target magnet 20 is depicted in various states. For example, Figure 2 depicts the conventional target magnet 20 outside the sensing region SA ( Figure 5 ) of the proximity switch 10, and the proximity switch 10 is in an inactive state. When the target magnet 20 moves (such as by rotating the shaft 16 via the actuator 14, which in turn rotates the target carrier 18) into the sensing region SA of the proximity switch 10, the proximity switch 10 is attracted to the target magnet 20, which has an end with a magnetic polarity opposite to that of the end of the proximity switch 10. Configured in this way, this arrangement causes the proximity switch 10 to move to an active state, as shown in Figure 3 .

[0006] However, once the proximity switch 10 is triggered or activated to the activated state by the target magnet 20, stopping and immediately reversing the direction of the target magnet 20 does not immediately reset the proximity switch 10. Instead, due to the hysteresis effect, the proximity switch 10 remains in the activated state until the target magnet 20 moves by an amount sufficient to disrupt the magnetic field outside the sensing region SA. When this occurs, the proximity switch 10 is released back to the non-activated state, as Figure 4 shown.

[0007] Now referring to Figure 5 , the target magnet 20 is polarized such that the N pole faces the opposite S pole of the sensing magnet 11 of the proximity switch, and the sensing magnet 11 is disposed adjacent to the target magnet 20. When the target magnet 20 moves into the sensing region SA of the proximity switch 10, the proximity switch 10 is attracted to the target magnet 20, actuated to the activated state, and remains in the activated state until the target magnet 20 moves out of the sensing region SA of the proximity switch 20 plus hysteresis. For example, this hysteresis can significantly delay the return of the proximity switch 10 to the non-activated state. This also reduces the accuracy of determining the rotational position of the actuator 14 at any given time. SUMMARY OF THE INVENTION

[0008] According to an exemplary aspect of the present invention, a process control system includes an actuator having a rotatable shaft. A proximity switch is coupled to the actuator and adjacent to the rotatable shaft, and includes a sensing magnet having a magnetic polarity that generates a sensing region. A target magnet mechanism is coupled to the actuator. The target magnet mechanism has a plurality of magnets arranged in an alternating magnetic pole configuration that forms a narrowed magnetic field of the target magnet mechanism. The plurality of magnets includes a central magnet and flank magnets, the central magnet having an end with a magnetic polarity opposite to the magnetic polarity of the sensing magnet of the proximity switch, and the flank magnets are disposed on at least one side of the central magnet. The flank magnets include a magnetic polarity opposite to the magnetic polarity of the central magnet and the same as the magnetic polarity of the sensing magnet. Configured in this way, when rotating the rotatable shaft, the plurality of magnets move towards the sensing region of the proximity switch until the central magnet attracts the sensing magnet of the proximity switch, thereby triggering the proximity switch into the activated state. When the target magnet mechanism moves out of the sensing region, the flank magnets repel the sensing magnet of the proximity switch, thereby releasing the proximity switch into the deactivated state.

[0009] According to another aspect of the present disclosure, a target magnet mechanism for a proximity switch includes a plurality of magnets arranged in an alternating magnetic pole configuration that forms a narrowed magnetic field of the target magnet mechanism. The plurality of magnets includes a central magnet and flank magnets. The central magnet has an end with a magnetic polarity opposite to that of the sensing magnet of the proximity switch, and the flank magnets are disposed beside the sensing magnet. The flank magnets include a magnetic polarity opposite to that of the central magnet and the same as that of the sensing magnet. Configured in this way, the plurality of magnets causes a state change of the proximity switch by one of the following: pulling the magnetic field of the proximity switch via the opposite polarities of the central magnet among the plurality of magnets and the sensing magnet of the proximity switch, thereby triggering the proximity switch to enter an activated state, or pushing the magnetic field of the proximity switch via the same polarities of the flank magnets among the plurality of magnets and the sensing magnet of the proximity switch, thereby releasing the proximity switch to enter a deactivated state.

[0010] According to yet another aspect of the present disclosure, a method of changing the state of a proximity switch operatively coupled to an actuator includes moving a plurality of magnets of a target magnet mechanism into a sensing region of the proximity switch and triggering an activated state of the proximity switch by attracting the sensing magnet of the proximity switch via a central magnet of the plurality of magnets, the central magnet having a magnetic polarity opposite to that of the sensing magnet of the proximity switch. The method further includes moving the plurality of magnets away from the sensing region of the proximity switch; and deactivating the proximity switch by repelling the sensing magnet of the proximity switch via flank magnets of the plurality of magnets, the flank magnets and the sensing magnet having the same magnetic polarity.

[0011] Further according to any one or more of the exemplary aspects, the process control system, target magnet mechanism, or any method of the present disclosure may include any one or more of the following preferred forms.

[0012] In some preferred forms, the process control system may further include a target carrier coupled to the rotatable shaft. The target carrier may be a rotatable disk having a central opening for receiving the rotatable shaft, and the target magnet mechanism is disposed on the rotatable disk. Additionally, the target carrier may include one or more target magnet mechanisms. Further, the flank magnets may include flank magnets disposed on one or both sides of the central magnet among the plurality of magnets, and each flank magnet has an end with a magnetic polarity the same as that of the end of the sensing magnet of the proximity switch, such that when the target magnet mechanism moves out of the sensing area of the proximity switch, the flank magnet repels the sensing magnet and releases the proximity switch back to the unactivated state. Further, the flank magnets may include flank magnets disposed on either side of the central magnet among the plurality of magnets, and each flank magnet has an end with a magnetic polarity opposite to that of the central magnet among the plurality of magnets.

[0013] In other preferred forms, the narrowed magnetic field of the target magnet mechanism may form the narrowed magnetic field and sensing area of the proximity switch. Additionally, the narrowed magnetic field of the target magnet mechanism may reduce the trigger window of the proximity switch.

[0014] In other forms, the target magnet mechanism may cause a change in the state of the proximity switch by one of the following: (1) pulling on the magnetic field of the proximity switch via opposite polarities of the central magnet among the plurality of magnets and the sensing magnet of the proximity switch; or (2) pushing on the magnetic field of the proximity switch via the same polarities of the flank magnets among the plurality of magnets and the sensing magnet of the proximity switch.

[0015] In other forms, moving the plurality of magnets of the target magnet mechanism into the sensing area of the proximity switch may include: rotating in a first direction a shaft operably coupled to an actuator and the target carrier, thereby rotating the plurality of magnets disposed on the target carrier relative to the axis of the shaft. Additionally, triggering the activated state of the proximity switch by attracting the sensing magnet of the proximity switch via the central magnet among the plurality of magnets may include: pulling on the narrowed magnetic field of the proximity switch by attracting the sensing magnet of the proximity switch via the central magnet among the plurality of magnets. Further, the method may further include: narrowing the magnetic fields of the target magnet mechanism and the proximity switch via the plurality of magnets of the target magnet mechanism. Additionally, deactivating the proximity switch by repelling the sensing magnet of the proximity switch via the flank magnets among the plurality of magnets may include: pushing on the magnetic field of the proximity switch by repelling the sensing magnet of the proximity switch via the flank magnets among the plurality of magnets.

[0016] Other optional aspects and features are also disclosed, which may be arranged in any functionally suitable manner, either individually or in any functionally feasible combination, consistent with the teachings of this disclosure. Other aspects and advantages will become apparent in light of the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1A is a perspective view of a conventional target magnet and a magnetic proximity switch, the magnetic proximity switch being disposed within a switch housing with the lid removed;

[0018] Figure 1B is Figure 1A a top view of the conventional target magnet and magnetic proximity switch of

[0019] Figure 2 is a front view of the conventional target magnet proximate to the magnetic proximity switch in an unactivated state;

[0020] Figure 3 is a front view of the conventional target magnet activating or triggering the magnetic proximity switch to an activated state;

[0021] Figure 4 is a front view of the conventional target magnet deactivating or releasing the magnetic proximity switch back to an unactivated state, depicting the hysteresis effect;

[0022] Figure 5 is a top view of the conventional target magnet and magnetic proximity switch, depicting the magnetic field of the target magnet, the sensing field of the magnetic proximity switch, and the rotational range of the target magnet to move into or out of the sensing field of the magnetic proximity switch;

[0023] Figure 6 is a perspective view of a target magnet mechanism according to an aspect of this disclosure, the target magnet mechanism being coupled to a proximity switch;

[0024] Figure 7 is Figure 6 a top view of the target magnet mechanism and proximity switch of

[0025] Figure 8A is a perspective view of an exemplary target magnet mechanism of this disclosure;

[0026] Figure 8B is Figure 8A a partial exploded perspective view of the target magnet mechanism of

[0027] Figure 9 is a perspective view of another exemplary target magnet mechanism of this disclosure;

[0028] Figure 10 isFigure 9 Another perspective view of the target magnet mechanism;

[0029] Figure 11 Is a front view of the target magnet mechanism of the present disclosure near a proximity switch in an unactivated state;

[0030] Figure 12 Is a perspective view of the target magnet mechanism of the present disclosure activating the proximity switch to an activated state;

[0031] Figure 13 Is a perspective view of the target magnet mechanism of the present disclosure deactivating or releasing the proximity switch back to the unactivated state and the hysteresis window; and

[0032] Figure 14 Is a top view of the target magnet mechanism of the present disclosure coupled to the proximity switch, depicting the magnetic field of the target magnet mechanism, the sensing field of the proximity switch, and the rotational range of the target magnet for moving into or out of one or more of the sensing fields of the magnetic proximity switch. DETAILED DESCRIPTION

[0033] The present disclosure relates to a target magnet mechanism for a proximity switch, such as a magnetically biased, actuated proximity switch. The proximity switch includes a sensing magnet and is operatively coupled to an actuator that is coupled to, for example, a process control valve. The target magnet mechanism includes a plurality of magnets arranged in an alternating pole configuration that forms a narrowing magnetic field of the target magnet mechanism. The plurality of magnets includes a central magnet and flanking magnets, the central magnet having a magnetic polarity opposite to that of the sensing magnet of the proximity switch, and the flanking magnets being disposed alongside the central magnet. The flanking magnets include a magnetic polarity opposite to that of the central magnet and the same as that of the sensing magnet. Configured in this way, the plurality of magnets pull on the magnetic field of the proximity switch via the opposite polarities of the central magnet among the plurality of magnets and the sensing magnet of the proximity switch, thereby triggering the proximity switch to an activated state. Additionally, the plurality of magnets push on the magnetic field of the proximity switch via the same polarities of the flanking magnets among the plurality of magnets and the sensing magnet of the proximity switch, thereby releasing the proximity switch into the unactivated state. As a result, the switch hysteresis effect is reduced, the sensing area of the proximity switch is narrower, and the reset of the proximity switch is faster, as described in more detail below.

[0034] Now referring to Figure 6 , a process control system 100 is depicted in accordance with aspects of the present disclosure. The process control system 100 includes a control device 108 and an actuator 114 operatively coupled to the control device 108. The control device 108 can be a valve controller (such as Topworx TMa valvetop discrete valve controller) or a control valve such as a rotary control valve, and is operatively coupled to the output shaft 116 of the actuator 114. The output shaft 116 includes a longitudinal axis, and the actuator 114 rotates the shaft 116 relative to the longitudinal axis. A portion of the switch box 112 is coupled to the actuator 114 and includes a proximity switch 110 that is also coupled to the actuator 114 and is adjacent to the rotatable shaft 116. The proximity switch 110 includes a sensing magnet 111, as described in more detail below.

[0035] Also as Figure 7 shown, the target carrier 118 is further coupled to the rotatable shaft 116 and receives the target magnet mechanism 120 of the present disclosure. In one example, the target carrier 118 is a rotatable disk that has a central opening 118a for receiving at least one target magnet mechanism 120. Although Figure 7 in one target magnet mechanism 120 is provided on the target carrier 118, one or more of a pair of target magnet mechanisms 120 or more than two target magnet mechanisms may alternatively be provided on the target carrier 118 and still fall within the scope of the present disclosure. At least one target magnet mechanism 120 may be within and move along a curved slot 118b ( Figure 7 ) formed in the target carrier 118. Those of ordinary skill in the art will further understand that the target carrier 118 may additionally or alternatively include various other shapes and still fall within the scope of the present disclosure.

[0036] Now referring to Figures 8A - 10 , various exemplary target magnet mechanisms 120 according to the present disclosure are depicted. For example, Figure 8A depicts one exemplary target magnet mechanism 120a having a cylindrical shape. More specifically, the target magnet mechanism 120a includes a plurality of magnets 122 ( Figure 8B ) arranged in an alternating magnetic pole configuration to form a narrowed magnetic field of the target magnet mechanism, as Figure 14 shown and described in more detail below. The plurality of magnets 122 includes a central magnet 124 that has an end 124a with a magnetic polarity opposite to that of the sensing magnet 111 of the proximity switch 110. For example, in one example, the end 124a of the central magnet 124 may have an N magnetic pole opposite to the S magnetic pole of the sensing magnet 111. Alternatively, although not depicted, the end 124a of the central magnet 124 may have an S magnetic pole, and the sensing magnet 111 would then have an N magnetic pole, opposite to the end 124a of the central magnet 124.

[0037] As Figure 8AAs further shown, the plurality of magnets 122 may also include flank magnets 126 (such as external magnets or annular magnets) disposed on at least one side of the central magnet 124. The flank magnets 126 include a magnetic polarity opposite to that of the central magnet 124 and the same as that of the sensing magnet 111. More specifically, in one example, the flank magnet 126 has an end 126a that has, for example, an S magnetic polarity opposite to the N magnetic polarity of the end 124a of the central magnet and the same as the S magnetic polarity of the sensing magnet 111. Alternatively, the magnetic polarity of the end 126a of the flank magnet 126 may be an N magnetic polarity, the magnetic polarity of the end 124a of the central magnet may be an S magnetic polarity, and the magnetic polarity of the sensing magnet 111 of the proximity switch 110 may be an N magnetic polarity, such that the magnetic polarity of the flank magnet 126 is again opposite to that of the central magnet 124 and the same as that of the sensing magnet 111.

[0038] Now referring to Figure 9 and Figure 10 , another exemplary target magnet mechanism 120b is depicted. Different from the target magnet mechanism 120a, the target magnet mechanism 120b may be rectangular in shape. As will be understood by those of ordinary skill in the art, each of the target magnet mechanisms 120a, 120b may take the form of various other shapes and still fall within the scope of the present disclosure.

[0039] However, similar to the target magnet mechanism 120a, the target magnet mechanism 120b also includes a plurality of magnets 128 arranged in an alternating configuration, for example, as Figure 10 shown. This configuration forms a narrowed magnetic field of the target magnet mechanism 120b, for example, as Figure 9 shown. In this example, the plurality of magnets 128 also includes a central magnet 130 having an end 130a with a magnetic polarity opposite to that of the sensing magnet 111 of the proximity switch 110. For example, in one example, the end 130a may have an N magnetic polarity (as Figure 10 shown), which is, for example, opposite to the S magnetic polarity of the sensing magnet 111 shown in Figure 6 and Figure 11 .

[0040] The plurality of magnets 128 may also include flank magnets 132 disposed on at least one side of the central magnet 130. In one example, the flank magnets 132 include a magnetic polarity opposite to that of the central magnet 130 and the same as that of the sensing magnet 111 of the proximity switch 110. More specifically, as Figure 10As shown, for example, the flank magnet 132 has an end 132a that has an S magnetic polarity, which is opposite to the N magnetic pole of the end 130a of the central magnet 130 and the same as the S magnetic polarity of the sensing magnet 111 of the proximity switch 110.

[0041] In another example, and as Figure 9 and Figure 10 shown, the flank magnet 132 can include a pair of flank magnets such that the flank magnet 132 is disposed on each side of the central magnet 130 among the plurality of magnets 128. In this example, each flank magnet 132 has an end 132a that has a magnetic polarity the same as that of the sensing magnet 111 of the proximity switch 110. As a result, the flank magnets 132 disposed on each side of the central magnet 130 among the plurality of magnets 128 repel the sensing magnet 111 and release the proximity switch 110 back to an unactivated state, such as an at-rest state, as described in more detail below. Additionally, the end 132a of each flank magnet 132 has a magnetic polarity opposite to that of the end 130a of the central magnet 130, for example, as Figure 10 shown. As will be understood by those of ordinary skill in the art, the magnetic polarity of each of the flank magnet 132, the central magnet 130, and the sensing magnet 111 can be, for example, opposite to that as Figure 10 and Figure 14 shown, and still operate as described above and below, and still fall within the scope of the present disclosure.

[0042] Configured as such, when the shaft 116 rotates, the target carrier 118 and the target magnet mechanism 120, 120a, 120b having the plurality of magnets 122, 128 move toward the sensing region SA ( Figure 14 ) of the proximity switch 110, for example, as Figure 11 shown. At this time, the proximity switch 110 is in an unactivated state, such as a stationary state.

[0043] As Figure 12 shown, the target magnet mechanism 120, 120a, 120b further moves into the sensing region SA of the proximity switch 110 until the central magnets 124 ( Figure 8B ), 130 ( Figure 9 and Figure 10 ) attract the sensing magnet 111 of the proximity switch 110. At this time, the proximity switch 110 is triggered or activated into an activated state. In other words, the target magnet mechanism 120, 120a, 120b passes through the central magnets 124 ( Figure 8B ), 130 ( Figure 9 and Figure 10) and the opposite polarity of the sensing magnet 111 of the proximity switch pulls on the magnetic field of the proximity switch 110 to change the state of the proximity switch 110 from a stationary or unactivated state to an activated state. This movement triggers the proximity switch 110 to enter the activated state.

[0044] When the target magnet mechanisms 120, 120a, 120b and thus the plurality of magnets 122 ( Figure 8B ), 128 ( Figure 9 ) move out of the sensing area SA, the flanking magnets 126 ( Figure 8B ), 132 ( Figure 9 and Figure 10 ) repel the sensing magnet 111 of the proximity switch 110. As a result, the proximity switch 110 is released into a deactivated or unactivated state, such as a stationary state, as Figure 13 shown. In other words, because the flanking magnets 126 ( Figure 8B ), 132 ( Figure 9 and 10 ) have the same polarity as the sensing magnet 111 of the proximity switch 110 (such as a primary magnet), when the target magnet mechanisms 120, 120a, 120b move out of the sensing area SA, the flanking magnets 126 ( Figure 8B ), 132 ( Figure 9 and Figure 10 ) repel the proximity switch 110 back to its stationary position.

[0045] Thus, as Figure 13 shown, for example, when the target magnet mechanisms 120, 120a, 120b are in front of the sensing area SA of the proximity switch 110, the normally closed contact pressure increases. In other words, the target magnet mechanisms 120, 120a, 120b cause a state change of the proximity switch 110 from an activated state to a deactivated or unactivated state by pushing on the magnetic field of the proximity switch 110 via the same magnetic polarity of the flanking magnets 126 ( Figure 8B ), 132 ( Figure 9 and Figure 10 ) and the sensing magnet 111 of the proximity switch 110. This movement releases the proximity switch 110 into the unactivated state.

[0046] Now referring to Figure 14 , some advantages of the target magnet mechanisms 120, 120a, 120b of the present disclosure are depicted. For example, Figure 8B and Figure 9Multiple magnets 122, 128 form a narrowed magnetic field of the target magnet mechanisms 120, 120a, 120b respectively in an alternating pole configuration. As a result, a narrowed magnetic field and a sensing region SA of the proximity switch 110 are formed. In addition, the narrowed magnetic fields of the target magnet mechanisms 120, 120a, 120b reduce the trigger window of the proximity switch 110. Furthermore, as Figure 14 further shown in, the narrowed sensing region SA generally results in a reduced total rotation range of the target magnet mechanisms 120, 120a, 120b. Specifically, the hysteresis effect is significantly reduced, and the rotation range of the sensing region SA (such as a dead band) is also reduced. As a result, the target magnet mechanisms 120, 120a, 120b have a tighter or squeezed magnetic field, causing the switch to activate and release, for example, in a narrower window and at a faster rate.

[0047] Configured in this way, the control valve system 100 and the target magnet mechanisms 120, 120a, 120b can be operated according to an exemplary method. Specifically, for example, a method of changing the state of the proximity switch of the control valve system 100 may include: moving the multiple magnets 122, 128 of the target magnet mechanisms 120, 120a, 120b into the sensing region SA of the proximity switch 110. In one example, moving the multiple magnets 122, 128 of the target magnet mechanisms 120, 120a, 120b into the sensing region SA of the proximity switch 110 may include: rotating the shaft 116 operably coupled to the actuator 114 and the target carrier 118 in a first direction (such as a clockwise direction), thereby rotating the multiple magnets 122, 128 provided on the target carrier 118 relative to the axis of the shaft 116.

[0048] The method may further include: attracting the sensing magnet 111 of the proximity switch 110 to the central magnets 124, 130 having a polarity opposite to that of the sensing magnet 111 via the central magnets 124, 130 among the multiple magnets 122, 128 to trigger the activation state of the proximity switch 110, as described above. In one example, attracting the sensing magnet 111 of the proximity switch 110 via the central magnets 124, 130 to trigger the activation state of the proximity switch 110 includes: attracting the inductive magnet 111 of the proximity switch 110 via the central magnets 124, 130 among the multiple magnets 122, 128 to pull on the narrowed magnetic field of the proximity switch 110.

[0049] The method may further include: moving the plurality of magnets 122, 128 away from the sensing region SA of the proximity switch 110. In one example, moving the plurality of magnets 122, 128 away from the sensing region SA of the proximity switch 110 includes: rotating the plurality of magnets 122, 128 in a second direction (such as a counterclockwise direction), the second direction being opposite to the first direction in which the plurality of magnets 122, 128 are rotated, for example, to start activating the proximity switch 110.

[0050] The method may further include: deactivating the proximity switch 110 by repelling the sensing magnet 111 of the proximity switch 110 via the flank magnets 126, 132 among the plurality of magnets 122, 128, the flank magnets 126, 132 and the sensing magnet 111 having the same magnetic polarity, as described above. In one example, deactivating the proximity switch 110 by repelling the sensing magnet 111 of the proximity switch 110 via the flank magnets 126, 132 among the plurality of magnets 122, 128 may include: pushing the magnetic field of the proximity switch 110 by repelling the sensing magnet 111 of the proximity switch 110 via the flank magnets 126, 132.

[0051] In view of the foregoing, those of ordinary skill in the art will appreciate many advantages of the disclosed target magnet mechanisms 120, 120a, 120b and related methods. For example, the use of a plurality of magnets among the plurality of magnets 122, 128, with the magnet stacks having aligned poles, for example, compresses, tightens, and narrows the magnetic fields of the target magnet mechanisms 120, 120a, and 120b as well as the magnetic field of the proximity switch 110. As a result, the rotation range of the target magnet mechanisms 120, 120a, 120b is reduced, thereby allowing the proximity switch 110 to change states at a faster rate compared to conventional target magnets used for proximity switches. In addition, the narrowed magnetic field of the target magnet mechanisms 120, 120a, 120b causes the proximity switch 110 to be triggered only in the narrowed sensing region (such as a dead zone window) of the proximity switch 110.

[0052] In addition, the target magnet mechanisms 120, 120a, 120b of the present disclosure also significantly reduce the hysteresis effect of conventional target magnets and proximity switches. This reduces the time that the proximity switch 110 remains in the activated state because the target magnet mechanisms 120, 120a, 120b have a shorter rotational movement range to move out of the sensing region SA of the proximity switch 110 to, for example, deactivate the proximity switch 110. In summary, the above-described configuration of the plurality of magnets 122, 128 and the repulsive magnetic field result in a tighter sensing of the proximity switch 110 and thus faster actuation and deactivation of the proximity switch 110.

[0053] Although certain control valves and systems have been described herein in accordance with the teachings of the present disclosure, the scope of coverage of this patent is not limited thereto. On the contrary, while the invention has been shown and described in conjunction with various preferred embodiments, it is apparent that certain changes and modifications can be made in addition to those mentioned above. This patent covers all embodiments of the teachings of the present disclosure that fall completely within the scope of the permitted equivalents. Accordingly, the invention is intended to cover all changes and modifications that may occur to those of ordinary skill in the art.

[0054] The following additional considerations apply to the foregoing discussion. Throughout the specification, multiple instances may implement components, operations, or structures that are described as a single instance. Although the individual operations of one or more methods are shown and described as separate operations, one or more of the individual operations may be performed simultaneously and need not be performed in the order shown. Structures and functions that are presented as separate components in an exemplary configuration may be implemented as a combined structure or component. Similarly, structures and functions that are presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements fall within the scope of the subject matter herein.

[0055] Unless otherwise expressly specified, discussions herein using words such as "processing," "computing," "calculating," "determining," "presenting," "displaying," etc., can refer to actions or processes of a machine (e.g., a computer) that manipulates or transforms data represented as physical (e.g., electronic, magnetic, or optical) quantities within one or more memories (e.g., volatile memory, non-volatile memory, or a combination thereof), registers, or other machine components that receive, store, transmit, or display information.

[0056] As used herein, any reference to "one embodiment," "an embodiment," "embodiments," or "the embodiments" means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The phrase "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment.

[0057] Some embodiments may be described using the expression "coupled" and its derivatives. For example, the term "coupled" may be used to describe some embodiments to indicate that two or more elements are in direct physical or electrical contact. However, the term "coupled" may also mean that two or more elements are not in direct contact with each other but still cooperate or interact with each other. The embodiments are not limited to this context.

[0058] As used herein, the terms "comprising," "comprises," "including," "includes," "has," "having" or any other variation thereof are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive or and not an exclusive or. For example, any one of the following satisfies the condition A or B: A is true (or present) and B is false (or absent), A is false (or absent) and B is true (or present), and both A and B are true (or present).

[0059] Additionally, the articles "a" or "an" are used to describe elements and components of the implementations herein. This is done merely for convenience and to give a general sense of the invention. This description should be read to include one or at least one, and the singular also includes the plural, unless it is obvious that the contrary is intended.

[0060] Furthermore, the patent claims at the beginning of this patent application are not to be construed under 35 U.S.C § 112(f), unless traditional means-plus-function language is expressly recited, such as "means for... " or "step for... " language expressly recited in the claims. The systems and methods described herein relate to improvements to computer functionality and improve the functionality of conventional computers.

[0061] Although various embodiments have been described above, the present disclosure is not intended to be limited thereto. Variations may be made to the disclosed embodiments that are still within the scope of the appended claims.

Claims

1. A process control system, comprising: An actuator having a rotatable shaft; A proximity switch coupled to the actuator and adjacent to the rotatable shaft, the proximity switch having a sensing magnet with a magnetic polarity that generates a sensing region; And A target magnet mechanism coupled to the proximity switch, the target magnet mechanism having a plurality of magnets arranged in an alternating magnetic pole configuration that forms a narrowed magnetic field of the target magnet mechanism, the plurality of magnets including a central magnet and flanking magnets, the central magnet having an end with a magnetic polarity opposite to that of the sensing magnet of the proximity switch, the flanking magnets being disposed on at least one side of the central magnet, the flanking magnets including a magnetic polarity opposite to that of the central magnet and the same as that of the sensing magnet of the proximity switch, Wherein, upon rotation of the rotatable shaft, the plurality of magnets move towards the sensing region of the proximity switch until the central magnet attracts the sensing magnet of the proximity switch, thereby triggering the proximity switch into an activated state, and when the target magnet mechanism is moved out of the sensing region, the flanking magnets repel the sensing magnet of the proximity switch, thereby releasing the proximity switch into a deactivated state.

2. The process control system according to claim 1, further comprising a target carrier coupled to the rotatable shaft, the target magnet mechanism being coupled to the target carrier, wherein, The target carrier is a rotatable disk having a central opening for receiving the rotatable shaft, and the target carrier magnet mechanism is disposed on the rotatable disk.

3. The process control system according to claim 2, wherein, The target carrier includes a pair of target magnet mechanisms.

4. The process control system according to claim 1, wherein, The flanking magnets include flanking magnets disposed on either side of the central magnet in the plurality of magnets, each flanking magnet having an end with a magnetic polarity the same as that of the end of the sensing magnet of the proximity switch, such that when the target magnet mechanism moves out of the sensing region of the proximity switch, the flanking magnets repel the sensing magnet and release the proximity switch back to the non-activated state.

5. The process control system according to claim 1, wherein, The flanking magnets include flanking magnets disposed on either side of the central magnet in the plurality of magnets, each flanking magnet having an end with a magnetic polarity opposite to that of the central magnet in the plurality of magnets.

6. The process control system according to claim 1, wherein, The narrowed magnetic field of the target magnet mechanism forms the narrowed magnetic field and sensing region of the proximity switch.

7. The process control system according to claim 1, wherein, The narrowed magnetic field of the target magnet mechanism reduces the triggering window of the proximity switch.

8. The process control system according to claim 1, wherein, The target magnet mechanism causes a state change of the proximity switch by one of the following: (1) pulling on the magnetic field of the proximity switch via the opposite polarities of the central magnet in the plurality of magnets and the sensing magnet of the proximity switch; Or (2) pushing on the magnetic field of the proximity switch via the same polarities of the flanking magnets in the plurality of magnets and the sensing magnet of the proximity switch.

9. The process control system according to claim 6, wherein, The narrowed sensing region results in a reduced total rotation range of the target magnet mechanism.

10. A target magnet mechanism for a proximity switch, the proximity switch having a sensing magnet and being operably coupled to an actuator having a shaft, the target magnet mechanism comprising: A plurality of magnets, the plurality of magnets being arranged in an alternating magnetic pole configuration that forms a narrowed magnetic field of the target magnet mechanism, the plurality of magnets including a central magnet and flank magnets, the central magnet having an end with a magnetic polarity opposite to that of the sensing magnet of the proximity switch, the flank magnets being disposed beside the sensing magnet, the flank magnets including a magnetic polarity opposite to that of the central magnet and the same as that of the sensing magnet. The plurality of magnets cause a state change of the proximity switch by one of the following: pulling the magnetic field of the proximity switch via the opposite magnetic polarities of the central magnet among the plurality of magnets and the sensing magnet of the proximity switch, thereby triggering the proximity switch to enter an activated state, or pushing the magnetic field of the proximity switch via the same magnetic polarities of the flank magnets among the plurality of magnets and the sensing magnet of the proximity switch, thereby releasing the proximity switch to enter a deactivated state.

11. The target magnet mechanism according to claim 10, wherein, The flank magnets include flank magnets disposed on either side of the central magnet among the plurality of magnets, each flank magnet having an end with a magnetic polarity the same as that of the end of the sensing magnet of the proximity switch, such that when the target magnet mechanism moves out of the sensing area of the proximity switch, the flank magnets repel the sensing magnet and release the proximity switch to the deactivated state.

12. The target magnet mechanism according to claim 10, wherein, The flank magnets include flank magnets disposed on either side of the central magnet among the plurality of magnets, each flank magnet having an end with a magnetic polarity opposite to that of the central magnet among the plurality of magnets.

13. The target magnet mechanism according to claim 10, wherein, The plurality of magnets are adapted to move into the sensing area of the proximity switch to trigger the proximity switch to enter an activated state when the central magnet among the plurality of magnets attracts the sensing magnet of the proximity switch.

14. The target magnet mechanism according to claim 10, wherein, The plurality of magnets are adapted to move away from the sensing area of the proximity switch to automatically release the proximity switch to a deactivated state when the flank magnets of the plurality of magnets repel the sensing magnet of the proximity switch.

15. The target magnet mechanism according to claim 10, wherein, The narrowed magnetic field of the target magnet mechanism generates a narrowed magnetic field and sensing area of the proximity switch.

16. A method of changing the state of a proximity switch operably coupled to an actuator, the method comprising: Moving a plurality of magnets of a target magnet mechanism into a sensing area of a proximity switch, wherein the plurality of magnets are arranged in an alternating magnetic pole configuration to form a narrowed magnetic field of the target magnet mechanism; Triggering an activated state of the proximity switch by attracting a sensing magnet of the proximity switch via a central magnet among the plurality of magnets, the central magnet having a magnetic polarity opposite to that of the sensing magnet of the proximity switch; Moving the plurality of magnets away from the sensing area of the proximity switch; and Deactivating the proximity switch by repelling the sensing magnet of the proximity switch via a flank magnet among the plurality of magnets, the flank magnet and the sensing magnet having the same magnetic polarity.

17. According to the method of claim 16, wherein, Moving a plurality of magnets of a target magnet mechanism into a sensing area of the proximity switch includes: rotating an axis operably coupled to an actuator and a target carrier in a first direction, thereby rotating the plurality of magnets disposed on the target carrier relative to an axis of the axis.

18. According to the method of claim 16, wherein, Triggering an activation state of the proximity switch by attracting a sensing magnet of the proximity switch via a central magnet among the plurality of magnets includes: pulling a narrowed magnetic field of the proximity switch by attracting the sensing magnet of the proximity switch via the central magnet among the plurality of magnets.

19. The method according to claim 17, further comprising: Narrowing magnetic fields of the target magnet mechanism and the proximity switch via the plurality of magnets of the target magnet mechanism.

20. According to the method of claim 16, wherein, Deactivating the proximity switch by repelling the sensing magnet of the proximity switch via a flank magnet among the plurality of magnets includes: pushing the magnetic field of the proximity switch by repelling the sensing magnet of the proximity switch via the flank magnet among the plurality of magnets.

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