WO2014131170A1

WO2014131170A1 - Electrical transfer switch system

Info

Publication number: WO2014131170A1
Application number: PCT/CN2013/071971
Authority: WO
Inventors: Jifeng FENG
Original assignee: General Electric Company
Priority date: 2013-02-28
Filing date: 2013-02-28
Publication date: 2014-09-04
Also published as: CN104285267A; CN104285267B

Abstract

A system includes an automatic transfer switch configured to be operated by hand to selectively route power from a first power source or a second power source to a load, comprising a switch configured to translate at least one link bar, wherein the at least one link bar is coupled to a rotatable linkage, and the rotatable linkage is configured to transfer motion of the at least one link bar to rotation of at least one shaft, and wherein the switch comprises at least one arm having first, second, and third surfaces, wherein the first, second, and third surfaces are crosswise to one another, and wherein the at least one link bar is in continuous contact with at least one of the first, second, or third surfaces during actuation of the switch.

Description

ELECTRICAL TRANSFER SWITCH SYSTEM

BACKGROUND OF THE INVENTION

[0001] The subject matter disclosed herein relates to electrical systems, and more specifically, to electrical switches.

[0002] Electrical systems may contain various electrical components, such as circuit breakers and transfer switches, which connect a power source to a load. For example, a transfer switch may selectively connect the load to a first power source or a second power source, depending on the availability of an operating condition of each power source. In the case of an automatic transfer switch, the transfer switch may automatically switch from the first power source to the second power source at a particular time, such as when the first power source becomes unavailable. Unfortunately, manual operation of the transfer switch may be inefficient and/or may require high amounts of force.

BRIEF DESCRIPTION OF THE INVENTION

[0003] Certain embodiments commensurate in scope with the originally claimed invention are summarized below. These embodiments are not intended to limit the scope of the claimed invention, but rather these embodiments are intended only to provide a brief summary of possible forms of the invention. Indeed, the invention may encompass a variety of forms that may be similar to or different from the embodiments set forth below.

[0004] In one embodiment, a system includes an automatic transfer switch configured to be operated by hand to selectively route power from a first power source or a second power source to a load, comprising first and second shafts, each of the first and second shafts comprising a plurality of moveable contacts configured to connect and disconnect with respective stationary contacts upon respective rotation of the first and second shafts, a switch configured to be moved between first and second positions, and first and second link mechanisms configured to translate movement of the switch into rotation of the first and second shafts, wherein the switch comprises a fork comprising first and second arms, and the first and second arms are configured to continuously abut against respective first and second link bars of the first and second link mechanisms when the switch is moved between the first position and the second position.

[0005] In a second embodiment, a system includes an automatic transfer switch configured to be operated by hand to selectively route power from a first power source or a second power source to a load, comprising a switch configured to translate at least one link bar, wherein the at least one link bar is coupled to a rotatable linkage, and the rotatable linkage is configured to transfer motion of the at least one link bar to rotation of at least one shaft, and wherein the switch comprises at least one arm having first, second, and third surfaces, wherein the first, second, and third surfaces are crosswise to one another, and wherein the at least one link bar is in continuous contact with at least one of the first, second, or third surfaces during actuation of the switch.

[0006] In a third embodiment, a system includes an automatic transfer switch configured to selectively route power from a first power source or a second power source to a load, comprising first and second stationary electrical contacts, first and second moveable electrical contacts, and a switch moveable between first and second positions, wherein the first moveable electrical contact is connected to the first stationary electrical contact and the second moveable electrical contact is disconnected from the second stationary electrical contact when the switch is in the first position, the first moveable electrical contact is disconnected from the first stationary electrical contact and the second moveable electrical contact is connected to the second stationary electrical contact when the switch is in the second position, and the switch comprises a variable force profile that decreases as the switch is moved from an intermediate position toward the closer of the first and second positions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

[0008] FIG. 1 is a perspective view of an embodiment of an electrical transfer switch configured to route current from a first power source or a second power source to a load;

[0009] FIG. 2 is a perspective view of an embodiment of the electrical transfer switch of FIG. 1 with the cover plate removed, illustrating a switch with a generally forked shape to improve manual operation of the transfer switch;

[0010] FIG. 3 is a side view of an embodiment of the switch of FIG. 2 disposed in an open middle position;

[0011] FIG. 4 is a side view of an embodiment of the switch of FIG. 2 disposed in an intermediate position between the open middle position and a closed position;

[0012] FIG. 5 is a side view of an embodiment of the switch of FIG. 2 disposed in the closed position; and

[0013] FIG. 6 is a graphical illustration of an embodiment of a force profile of the switch of FIG. 2 as the switch is moved between the open, intermediate, and closed positions.

DETAILED DESCRIPTION OF THE INVENTION

[0014] One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business -related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0015] When introducing elements of various embodiments of the present invention, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0016] The present disclosure is directed towards systems to improve the efficiency and operability of electrical transfer switches (e.g., automatic transfer switches (ATS)). In particular, it is desirable to decrease the amount of force needed for manual operation of the ATS. To this end, the ATS includes a switch that is moveable between first and second positions to selectively couple a first or a second power source to a load. The switch has a generally forked shape having two arms. Each arm has three surfaces which define and create a variable force profile during movement or actuation of the switch. That is, the manual force needed to move the switch decreases as the switch nears the first or second (e.g., open or closed) positions, thereby facilitating movement of the switch. In certain embodiments, the switch may rotate one or more link bars. The link bars may be coupled to one or more rotatable linkages, to one or more shafts, and ultimately, to one or more moveable electrical contacts that enable the ATS to switch (e.g., automatically switch) between the first and second power sources when a switch is operated. In operation, the three surfaces of each fork arm may continuously abut the link bars, thereby creating the variable force profile described above and increasing the efficiency and operability of the ATS.

[0017] Turning now to the figures, FIG. 1 illustrates a perspective view of an embodiment of a transfer switch (e.g., ATS 10) with features to improve the efficiency of making and breaking (e.g., switching) electrical connections within the ATS 10. The ATS 10 may route power from a first power source 12 or a second power source 14 toward a load 16. For example, the first power source 12 may be a power grid, and the second power source 14 may be a backup electrical generator. The load 16 may be any downstream user of electricity, such as a pump, motor, turbomachine, refrigeration system, gas turbine system, healthcare system, a building, and/or the like.

[0018] The ATS 10 includes one or more stationary electrical contacts 18 (e.g., electrical contact fingers) coupled or fixed to a base 20 of the ATS 10. Each stationary electrical contact 18 has a corresponding moveable electrical contact 22 (e.g., electrical contact fingers). When the moveable electrical contacts 22 and the stationary electrical contacts 18 are coupled together, a complete electrical circuit is formed, thereby enabling current to flow from the first power source 12 or the second power source 14 toward the load 16. As used herein, the term "moveable" generally means capable of being moved relative to the base 20 of the ATS 10 (e.g., by rotation of a shaft or actuation of a switch). For example, in the illustrated embodiment, the moveable electrical contacts 22 are capable of being moved (e.g., rotated) using a switch 24, whereas the stationary electrical contacts 18 are generally fixed in place relative to the base 20 of the ATS 10.

[0019] A first set of stationary and moveable electrical contacts 26 and 28 are associated with the first power source 12, and a second set of stationary and moveable electrical contacts 30 and 32 are associated with the second power source 14. When the first set of stationary and moveable electrical contacts 26 and 28 are coupled to one another, the ATS 10 forms a complete electrical circuit between the first power source 12 and the load 16. While contacts 26 and 28 are coupled, the electrical circuit between the second power source 14 and the load 16 is open or broken. Likewise, when the second set of stationary and moveable electrical contacts 30 and 32 are coupled to one another, the ATS 10 forms a complete electrical circuit between the second power source 14 and the load 16. While contacts 30 and 32 are coupled, the electrical circuit between the first power source 12 and the load 16 is open or broken.

[0020] As shown, the first set of stationary and moveable contacts 26 and 28 includes four stationary electrical contacts 18 and four moveable electrical contacts 22. Similarly, the second set of contacts stationary and moveable 30 and 32 includes four stationary electrical contacts 18 and four moveable electrical contacts 22. In certain configurations, the first and second sets of electrical contacts 26, 28, 30, and 32 may contain the same or different numbers of stationary and moveable electrical contacts 18 and 22. Accordingly, the ATS 10 may include any suitable number of stationary or moveable electrical contacts 18 and 22, such as 1, 2, 3, 4, 5, 6, or more.

[0021] The switch 24 may be moved between first and second positions 34 and 36 to open or close the electrical connection between the first power source 12 or the second power source 14 with the load 16. More specifically, when the switch 24 is in the first position 34, the first set of contacts 26 and 28 are coupled to one another, thereby closing the electrical circuit between the first power source 12 and the load 16, while opening the electrical circuit between the second power source 14 and the load 16. When the switch 24 is in the second position 36, the second set of contacts 30 and 32 are coupled to one another, thereby closing the electrical circuit between the second power source 14 and the load 16, while opening the electrical circuit between the first power source 12 and the load 16. As such, then the first set of contacts 26 and 28 are connected, the second set of contacts 30 and 32 are automatically disconnected by the ATS 10, and vice versa. Furthermore, when the switch 24 is in intermediate positions between the first and second positions 34 and 36, the load 16 is disconnected from both power sources 12 and 14. Thus, it may be desirable to reduce the amount of force needed to actuate the switch 24 in order to enable a faster transition between the first and second positions 34 and 36 and thereby enable a faster transition between switching the power source (e.g., first power source 12 and second power source 14) that is used to power the load 16.

[0022] The ATS 10 further includes a position indicator 38 that indicates a current position of the switch 24. For example, the position indicator 38 may include text, symbols, illustrations, lights, sounds, and/or other indicators to indicate when the switch 24 is in the first position 34, the second position 36, or intermediate positions therebetween. In the illustrated embodiment, the position indicator 38 is located on a cover plate 40 of the ATS 10. As will be appreciated, the cover plate 40 covers the switch 24 during operation of the ATS 10 to protect various features of the switch 24, which are illustrated in FIG. 2. [0023] FIG. 2 is a perspective view of an embodiment of the ATS 10 with the cover plate 40 removed to reveal features of the switch 24. As shown, the switch 24 includes a handle 42 (e.g., rod-shaped handle) at a first end 44 and a fork 46 disposed at a second end 48 opposite the first end 44. The handle 42 enables an operator to grab and manually actuate the switch 24 (e.g., by hand). When the switch 24 is moved or actuated, the fork 46 actuates one or more link bars 50 abutting to the fork 46. More specifically, first and second arms 47 and 49 of the fork 46 abut and are continuously coupled to the link bars 50 during operation of the ATS 10. The arms 47 and 49 push and/or translate the link bars 50 upon actuation of the switch 24. The link bars 50 translate movement of the switch 24 into rotation of one or more rotatable linkages 52, which transfer movement of the link bars 50 to one or more shafts 54 of the ATS 10. For example, in the illustrated embodiment, each rotatable linkage includes gear teeth 56 which engage with respective gear teeth 58 of one of the shafts 54. In other words, gears having the gear teeth 56 and 58 engage with one another. In certain embodiments, the gear teeth 56 and 58 may have an involute shape. The gear teeth 56 and 58 may also be formed on gears and may have an arc shape, or other suitable shape. In this manner, the gear teeth 56 and 58 may transfer rotation of the rotatable linkages 52 to the shafts 54. In certain embodiments, a gear ratio between the gear teeth 56 and 58 may vary to enable the rotatable linkages 52 and the shafts 54 to rotate with different ratios relative to one another. For example, a ratio of rotation between the rotatable linkages 52 and the shafts 54 may be approximately 3:1, 2: 1, 1 :1, 1:2, 1:3, or any subranges therebetween. In certain embodiments, the gear ratio may be selected in order to decrease the amount of force to move the switch 24 between the first and second positions 34 and 36. The switch 24 may also include other features designed to decrease the force to actuate the switch 24, as will be discussed in greater detail with respect to FIGS. 3-6.

[0024] Each of the shafts 54 is fixedly attached to one or more moveable contacts 22. As a result, rotation of the shafts 54 enables the coupling and decoupling of the stationary and moveable electrical contacts 18 and 22 from one another. More specifically, rotation of the one or more shafts 54 results in movement of the moveable electrical contacts 22 relative to the stationary electrical contacts 18, thereby connecting or disconnecting moveable electrical contacts 22 from the stationary electrical contacts 18. In this manner, the power sources 12 or 14 may be alternately connected and disconnected from the load 16. It should be noted that although multiple link bars 50, rotatable linkages 52, and shafts 54 are illustrated, certain embodiments may use any number of these respective components (e.g., 1, 2, 3, 4, 5, 6, or more) and the switch 24 may be designed accordingly. For example, the ATS 10 may include three link bars 50, and the fork 46 of the switch 24 may include three arms 47 or 49. In certain embodiments, there may be a correlation between the number of link bars 50 and the number of arms 47, 49 of the switch 24 (e.g., a 1: 1, 2: 1, or 3: 1 correspondence).

[0025] An interlock bar 55 couples the link bars 50 and the rotatable linkages 52 together. As mentioned above, the arms 47 and 49 of the fork 46 are in continuous contact with the link bars 50. As the link bars 50 are fixed relative to one another via the interlock bar 55, the interlock bar 55 helps ensure that the rotatable linkages 52 and the shafts 54 move in a predetermined and consistent manner relative to one another. That is, the interlock bar 55 reduces the possibility of undesired relative movement and/or rotation between the respective link bars 50, rotatable linkages 52, and shafts 54. Reducing undesired relative movement and/or rotation between these components improves the operability of the ATS 10 and increases the reproducibility of movement generated by actuation of the switch 24.

[0026] FIGS. 3-5 are side views of the switch 24 taken about line 3 -3 of FIG. 2. More specifically, FIG. 3 illustrates the switch 24 in a middle position 60 (e.g., an open position) in which the load 16 is disconnected from the first and second power sources 12 and 14. FIG. 4 illustrates the switch 24 in an intermediate position 62 between the middle position 60 and one of the first or second positions 34 or 36 (e.g., closed positions). Finally, FIG. 5 illustrates the switch 24 in a closed position 64 to route current from either the first 12 or the second power source 14 toward the load 16. That is, the closed position 64 may be the first position 34 shown in FIG. 2, in which the electrical connection between the first power source 12 and the load 16 is closed and the electrical connection between the second power source 14 and the load 16 is open. Alternatively, the closed position 64 may be the second position 36 shown in FIG. 2, in which the electrical connection between the second power source 14 and the load 16 is closed and the electrical connection between the first power source 12 and the load 16 is open. Thus, FIGS. 3-5 represent a transition of the switch 24 from the middle position 60, through the intermediate position 62, and to the closed position 64 (e.g., the first or second position 34 or 36 shown in FIG. 2).

[0027] As shown in FIG. 3, movement or actuation of the switch 24 results in rotation of the handle 42 and the fork 46 about a first axis of rotation 66. In other words, when the switch 24 is manually actuated, the handle 42 and the fork 46 pivot about the first axis of rotation 66, which may be created by a bolt, screw, or other fixed rotating shaft. As shown, in FIG. 3, each arm 47 and 49 of the fork 46 includes three separate surfaces (e.g., first, second, and third surfaces 72, 74, and 76) along which the link arms 50 will translate during actuation of the switch 24. In particular, the second and third surfaces 74 and 76 of each arm 47 and 49 are angled or inclined relative to the handle 42 of the switch 24. In the manner described below, these orientations of the second and third surfaces 74 and 76 of each arm 47 and 49 of the fork 46 will improve the ergonomics of the operation of the switch 24.

[0028] When the switch 24 is in the middle position 60 shown in FIG. 3, a first link bar 100 is shown abutting the second surface 74 of the arm 47 of the fork 46. To move the switch 24 to the closed position 64 shown in FIG. 5, a force F0 acting on the handle 42 is used to initiate movement of the switch 24. In operation, the force F0 (e.g., the moment acting on the switch 24 caused by force F0 applied at a distance L0 from the axis of rotation 66) may be at least partially offset by resultant forces Fl and F2, which are formed between the first link bar 100, a first rotating linkage 102, and the arm 47. More specifically, a resultant force Fl at a distance LI between the first link bar 100 and an axis of rotation 68 of the first rotatable linkage 102 creates a first reacting moment on the switch 24, and a resultant force F2 at a distance L2 between the axis of rotation 66 of the switch 24 and the first link bar 100 creates another reacting moment on the switch 24. In other words, application of the force F0 to the switch 24 results in the resultant forces Fl and F2 acting on the switch 24, which may ultimately counteract the force F0 needed to move the switch 24. As shown in FIG. 4, as the first link bar 100 moves from the second surface 74 to the first surface 72 of the arm 47, the distances LI and L2 may decrease. In this manner, the reacting moments acting on the switch 24 may decrease. As such, the force F0 acting on the handle 42 of the switch 24 may remain constant, yet provide increased movement of the switch 24.

[0029] In the closed position 64 shown in FIG. 5, the forces F0, Fl, and F2 are indicative of the forces that would be applied to move the switch 24 out of the closed position 64. As such, when the F0 force is applied to the handle 42 of the switch 24, the third surface 76 of the arm 49 of the fork 46 will apply force to a second link bar 104 of the ATS 10. In the manner similarly described above, as the force F0 is applied to the handle 42, the second link bar 104 will translate along the third surface 76 of the arm 49 and will eventually translate along the second surface 74, and then the first surface 72 of the arm 49. As the second and third surfaces 74 and 76 are angled or inclined relative to the handle 42, the second link bar 104 may translate more easily along these surfaces as the force F0 is applied to the handle 42. Furthermore, as the second link bar 104 translates along the third surface 76, the second surface 74, and the first surface 72 of the arm 49, the distances LI and L2 shown in FIG. 5 may decrease, thereby decreasing the reacting moments acting on the switch 24. In this manner, amount of force needed to move the switch 24 may be reduced.

[0030] The force F0 needed to initiate movement of the switch 24 varies based on the position of the switch 24, defining a variable force profile 70, illustrated in FIG. 6, during operation of the ATS 10. In other words, a variable amount of force may be applied to the switch 24 for a resultant (e.g., constant) amount of movement of the link bars 50. The variable force profile 70 is further defined by first, second, and third surfaces 72, 74, and 76 of the arms 47 and 49 of the fork 46. During movement or actuation of the switch 24, the link bars 50 (e.g., first and second link bars 100 and 104) continuously abut at least one of the surfaces 72, 74, or 76, as shown in FIGS. 3 - 5. The continuous contact between the link bars 50 and the surfaces 72, 74, and 76 enables the arms 47 and 49 to push and/or rotate the link bars 50, thereby rotating the shafts 54 and connecting or disconnecting the power sources 12 and 14 from the load 16. [0031] As shown, the surfaces 72, 74, and 76 are crosswise to one another and are configured to enable faster movement of the switch 24. For example, the second and third surfaces 74 and 76, which are inclined as shown in FIG. 3, enables the link bars 50 to slide quickly against the surfaces 74 and 76. For example, the surfaces 72, 74, and/or 76 may be at an angle of approximately 40 to 160, 50 to 150, 60 to 140, 70 to 130, 80 to 120, or 90 to 110 degrees relative to one another and/or relative to the handle 42 (e.g., a longitudinal axis of the handle 42). Furthermore, the surfaces 72, 74, and 76 may be designed such that at least one of the link bars 50 is in continuous contact with an inclined (e.g., relative to the handle 46) surface (e.g., surface 72, 74, and/or 76) in order to facilitate movement of the switch 24. For example, both link bars 50 are in contact with the inclined surfaces 74 in FIG. 3 , and the second link bar 104 is in contact with the third surface 76 in FIGS. 4 and 5.

[0032] FIG. 6 is a graphical illustration of an embodiment of the force profile 70 needed to move the switch 24 toward the closed position 64 (e.g., the first position 34 and/or the second position 36) through intermediate positions 62 (e.g., shown in FIG. 4). As will be appreciated, the closed position 64 may be the closer of the first or second positions 34 and 36 relative to the middle position 60 (e.g., the switch 24 position shown in FIG. 3). Advantageously, the surfaces 72, 74, and 76 of the arms 47 and 49 create the force profile 70 which decreases (e.g., continuously decreases and/or monotonically decreases) as the switch 24 approaches the closed position 64. For example, as one or more of the links bars 50 translates along the surfaces 72, 74, and 76 of the arms 47 and 49, the reaction moments generated on the switch 24 may be decreased. As such, the force F0 needed to manually operate the switch 24 is decreased, thereby improving the efficiency and operability of the switch 24 and the ATS 10.

[0033] Technical effects of the disclosed embodiments include systems to improve the efficiency and operability of the ATS 10. In particular, it is desirable to decrease the amount of the force F0 needed for manual operation of the switch 24. To this end, the ATS 10 includes the switch 24 that is moveable between the first and second positions 34 and 36 to selectively couple the first or second power source 12 or 14 to the load 16. The switch 24 includes the fork 46 that has the arms 47 and 49. Each arm 47 and 40 has the three surfaces 72, 74, and 76 (e.g., inclined surfaces) which define the variable force profile 70 during movement of the switch 24. That is, the manual force FO needed to move the switch 24 decreases as the switch 24 nears the first or second positions 34 or 36, thereby facilitating movement of the switch 24. In certain embodiments, the switch 24 may move or rotate the one or more link bars 50. The link bars 50 are coupled to the one or more rotatable linkages 52, one or more shafts 54, and ultimately, the one or more moveable electrical contacts 22 that enable the ATS 10 to switch between the first and second power sources 12 and 14. In operation, the three surfaces 72, 74, and 76 of each fork arm 47 and 49 may continuously abut the link bars 50, thereby creating the variable force profile 70 described above and increasing the efficiency and operability of the ATS 10.

[0034] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

CLAIMS:

1. A system, comprising:

an automatic transfer switch configured to be operated by hand to selectively route power from a first power source or a second power source to a load, comprising:

first and second shafts, each of the first and second shafts comprising a plurality of moveable contacts configured to connect and disconnect with respective stationary contacts upon respective rotation of the first and second shafts;

a switch configured to be moved between first and second positions; and

first and second link mechanisms configured to translate movement of the switch into rotation of the first and second shafts, wherein the switch comprises a fork comprising first and second arms, and the first and second arms are configured to continuously abut against respective first and second link bars of the first and second link mechanisms when the switch is moved between the first position and the second position.

2. The system of claim 1, wherein the automatic transfer switch is configured to route the power from the first power source to the load and block power from the second power source to the load when the switch is in the first position, the automatic transfer switch is configured to route the power from the second power source to the load and block power from the first power source to the load when the switch is in the second position, the automatic transfer switch is configured to disconnect the first power source and the second power source from the load when the switch is in an intermediate position between the first and second positions.

3. The system of claim 1, wherein the first and second link bars are coupled to respective first and second rotatable linkages of the first and second link mechanisms, the first and second rotatable linkages are coupled to the respective first and second shafts, and wherein movement of the switch is configured to translate the first and second link bars, rotate the first and second rotatable linkages, and rotate the first and second shafts.

4. The system of claim 3, wherein the first and second shafts comprise respective first gear teeth, the first and second rotatable linkages comprise respective second gear teeth, and the first and second gear teeth are engaged with one another and are configured to transfer rotation of the first and second rotatable linkages to the first and second shafts.

5. The system of claim 4, wherein the first and second gear teeth comprise an involute shape.

6. The system of claim 1, wherein each of the first and second arms of the switch comprises respective first, second, and third surfaces, wherein the first, second, and third surfaces are crosswise to one another, and at least one of the first and second link bars is in continuous contact with at least one of the first, second, or third surfaces of the first or second arm when the switch is moved between the first and second positions.

7. The system of claim 6, wherein the first, second, and third surfaces define a variable force profile that decreases as the switch is moved from an intermediate position of the switch toward the closer of the first or second positions of the switch.

8. The system of claim 1, wherein the automatic transfer switch comprises a position indicator configured to indicate a position of the switch.

9. A system, comprising:

a switch configured to translate at least one link bar, wherein the at least one link bar is coupled to a rotatable linkage, and the rotatable linkage is configured to transfer motion of the at least one link bar to rotation of at least one shaft, and wherein the switch comprises at least one arm having first, second, and third surfaces, wherein the first, second, and third surfaces are crosswise to one another, and wherein the at least one link bar is in continuous contact with at least one of the first, second, or third surfaces during actuation of the switch.

10. The system of claim 9, wherein the load comprises a pump, motor, turbomachine, refrigeration system, gas turbine system, or a healthcare system.

11. The system of claim 9, wherein the first power source comprises a power grid, and the second power source comprises a backup generator.

12. The system of claim 9, wherein the automatic transfer switch is configured to electrically connect the first power source and the load and electrically disconnect the second power source and the load when the switch is in a first position, the automatic transfer switch is configured to electrically connect the second power source and the load and electrically disconnect the first power source and the load when the switch is in a second position, the automatic transfer switch is configured to electrically disconnect the first power source and the second power source from the load when the switch is in an intermediate position between the first and second positions.

13. The system of claim 12, wherein the first, second, and third surfaces of the at least one arm define a variable force profile that decreases as the switch is moved from the intermediate position toward the closer of the first and second positions.

14. The system of claim 9, wherein the at least one shaft comprises first gear teeth, the rotatable linkage comprises second gear teeth, and the first and second gear teeth are coupled together.

15. The system of claim 9, wherein the at least one shaft comprises a plurality of moveable electrical contacts configured to connect and disconnect with a respective plurality of stationary contacts of the automatic transfer switch upon rotation of the at least one shaft.

16. A system, comprising:

an automatic transfer switch configured to selectively route power from a first power source or a second power source to a load, comprising:

first and second stationary electrical contacts;

first and second moveable electrical contacts; and

a switch moveable between first and second positions, wherein the first moveable electrical contact is connected to the first stationary electrical contact and the second moveable electrical contact is disconnected from the second stationary electrical contact when the switch is in the first position, the first moveable electrical contact is disconnected from the first stationary electrical contact and the second moveable electrical contact is connected to the second stationary electrical contact when the switch is in the second position, and the switch comprises a variable force profile that decreases as the switch is moved from an intermediate position toward the closer of the first and second positions.

17. The system of claim 16, wherein the switch comprises a fork with first and second arms, wherein each of the first and second arms comprises first, second, and third inclined surfaces, wherein the first, second, and third, surfaces are crosswise to one another and define the variable force profile of the switch.

18. The system of claim 16, comprising:

first and second link bars coupled to the switch;

first and second rotatable linkages coupled to the first and second link bars; and

first and second shafts coupled to the first and second rotatable linkages and the respective first and second moveable electrical contacts, wherein actuation of the switch is configured to translate the first and second link bars, rotate the first and second rotatable linkages, and rotate the first and second shafts.

19. The system of claim 18, wherein the first and second shafts each comprise first gear teeth, the first and second rotatable linkages each comprise second gear teeth, and the first and second gear teeth are engaged with one another and are configured to transfer rotation of the first and second rotatable linkages to the first and second shafts.

20. The system of claim 18, wherein the first and second link bars are coupled to one another by an interlock bar configured to maintain a fixed distance between the first and second link bars.