System and method for reduced torque switching

A switching device for industrial equipment having at least one pair of contacts includes a transfer member rotatably mounted in the switching device. The transfer member is configured to receive a first force applied to the switching device in a first direction and to receive a second force applied to the switching device in a second direction. A rocker arm, rotatably mounted in the switching device, engages the transfer member to receive the first force over a first angle of rotation and to receive the second force over a second angle of rotation. The second angle of rotation is less than the first angle of rotation. A lever arm is pivotally mounted within the switching device. The lever arm engages the rocker arm to move between an Off position and an On position, and a plunger is actuated by the lever arm to selectively open and close the contacts.

BACKGROUND INFORMATION

The subject matter disclosed herein relates to switching devices for industrial equipment. More specifically, an aspect of the invention relates to switching devices that include a rotary switching mechanism and a system for reducing the torque required to rotate the switch between the Off and On positions.

As is known to those skilled in the art, switching devices are components in an electrical circuit that may be controlled between an “On” state and an “Off” state. In the On state, the switching device establishes an electrical connection between contacts and allows electrical current to flow through the switching device from a power source to an electrical load. In the Off state, the switching device opens, or breaks, the electrical connection between contacts, preventing the electrical current from flowing through the switching device. Switching devices may be used, for example, as a circuit breaker, motor protection device, contactor to supply power to one or more branch circuits, or the like. The switching device may be manually or automatically actuated.

According to one style of manually activated switch, a rotary actuator is provided which rotates between an Off position and an On position. Within the switch, a mechanical linkage is provided which similarly transitions between an Off state and an On state as the rotary actuator is rotated between the Off position and the On position. The rotary actuator includes a handle on a rotary disk, where the rotary actuator is located on an external surface of the switch and is accessible by an operator. When the operator rotates the handle, the rotary actuator engages a mechanical linkage within the switch which allows a plunger to move a switching element within the switching device in a first direction as the switch or actuator transitions from a first state to a second state. The plunger is extended when transitioning from an On state to an Off state, causing separation of electrical contacts and breaking an electrical connection within the switch. A spring exerts a force against the plunger, causing the plunger to retract when transitioning from the Off state back to the On state, allowing the electrical contacts to reconnect and establish an electrical connection within the switch.

Typically, a switch requires actuation in both directions, that is from the Off state to the On state as well as from the On state to the Off state, at the same position within the switch. The mechanical linkage between the rotary actuator and the contacts typically provides a continuous linkage between the rotary actuator and the contacts, such that motion in a first direction will transition between the Off state and the On state at a particular location during the rotation and that motion in a second direction will transition between the On state and the Off state at the same location during the rotation. These continuous mechanical linkages require the force applied to the rotary actuator to move the mechanical linkage between states to be applied generally at the transition point. The rotary actuator, however, is often moved a greater distance, such as over a ninety-degree arc such that a clear indication is provided to an operator whether the switch is in the Off state or the On state. Thus, the entire force required to transition between states is applied over a limited range of rotation of the total travel of the actuator as the switch is toggled between the Off and On states.

Applying the entire force for transitioning between states at a single point in the rotation creates a jerky motion when operating the switch. An operator begins rotation with a light force applied to the actuator. At the transition point, the switch may temporarily stall rotation as the operator increases the force applied. Once the force applied by an operator is sufficient to overcome the mechanical linkage and the internal linkage transitions states, the actuator may jump forward through the rest of the rotation because the required force to travel over the remaining distance is less than the force required at the transition point.

Thus, it would be desirable to provide a mechanical linkage within a switch that provides for smoother operation over an extended range of motion of the actuator.

It would also be desirable to provide a mechanical linkage within a switch that provides a reduced level of torque be applied to the actuator over the extended range of motion, such that the switch provides a more uniform and easier operational feel during actuation.

BRIEF DESCRIPTION

According to one embodiment of the invention, an apparatus for a switch includes a first rotational member, a second rotational member, and a transfer member. The first rotational member includes a first engagement portion and a first coupling portion. The first engagement portion is configured to receive a force applied to the switch, and the first rotational member moves between a first position and a second position responsive to receiving the force applied to the switch. The second rotational member includes a second coupling portion and a second engagement portion. The second rotational member moves between a third position and a fourth position responsive to receiving the force applied to the switch. The transfer member includes a third coupling portion configured to engage the first coupling portion of the first rotational member and a fourth coupling portion configured to selectively engage the second coupling portion of the second rotational member. The transfer member receives the force applied to the switch from the first rotational member via the third coupling portion and transfers the force applied to the switch to the second rotational member via the fourth coupling portion. The transfer member is configured to move between a fifth position and a sixth position responsive to the first rotational member moving between the first position and the second position.

According to another embodiment of the invention, a method for reducing a force applied to a switch includes applying a first force to a rotary actuator of a switch in a first direction and applying a second force to the rotary actuator of the switch in a second direction. The first force causes the switch to transition between an Off position and an On position, and the second force causes the switch to transition between the On position and the Off position. The first force is applied over a first range of motion of the rotary actuator, and the second force is applied over a second range of motion of the rotary actuator, where the first range of motion is greater than the second range of motion.

According to still another embodiment of the invention, a switching device for industrial equipment having at least one pair of contacts includes a transfer member, a rocker arm, a plunger, and a mechanical linkage. The transfer member is mounted in the switching device, and the transfer member is configured to receive a first force applied to the switching device in a first direction and to receive a second force applied to the switching device in a second direction. The rocker arm is rotatably mounted in the switching device. The rocker arm engages the transfer member to receive the first force over a first angle of rotation, and the rocker arm receives the second force over a second angle of rotation, where the second angle of rotation is less than the first angle of rotation. The plunger is actuated to selectively open and close at least one pair of contacts in the switching device when the switching device is moved between the Off position and the On position. The mechanical linkage is operatively connected between the rocker arm and the plunger. The mechanical linkage engages the plunger to selectively close the at least one pair of contacts as the rocker arm moves over the first angle of rotation, and the mechanical linkage engages the plunger to selectively open the at least one pair of contacts as the rocker arm moves over the second angle of rotation.

DETAILED DESCRIPTION

The subject matter disclosed herein describes a mechanical linkage within a switch that provides for smoother operation over an extended range of motion of the actuator. The mechanical linkage includes a transfer member configured to receive the force applied to a rotary handle of the switch. The transfer member is slidably mounted within the switch. In an Off position, the transfer member engages a rocker arm. As the transfer member rotates between the Off and On positions, the transfer member causes the rocker arm to rotate between the Off and On positions. When the rocker arm has reached the On position, the transfer member is slidably moved away from the rocker arm, disengaging the rocker arm. As the rocker arm rotates along with the transfer member between the Off and On positions, the rocker arm engages a mechanical linkage connected between the rocker arm and a plunger. The plunger moves in a first direction and closes the electrical contacts of the switch, causing the switch to transition between the Off and On states.

When the switch is transferred from the On state back to the Off state, a boss engages a slot in the rocker arm. The boss begins applying the rotational force in the opposite direction to the slot in the rocker arm. As the rocker arm begins rotating from the On state to the Off state, the mechanical linkage begins transitioning back to the Off state. After a short period of rotation, the rocker arm and mechanical linkage transition from a stable position to a position in which at least one spring in the switch applies a force to and causes the mechanical linkage to jump back to the Off state. The mechanical linkage returning to the Off state, in turn, causes the rocker arm to also jump back to the Off state. The handle of the switch continues rotating to the Off state. When the handle of the switch reaches the Off state, the transfer member slides back toward the rocker arm and reengages the rocker arm. This combination of transfer member, rocker arm, and mechanical linkage results in a reduced level of torque required to rotate the actuator over the extended range of motion when transitioning from the Off state to the On state. The reduced level of torque, in turn, provides a more uniform and easier operational feel during actuation. The jump back to the Off state provides a quick disconnection of the internal contacts and a reduce force required to rotate the handle back to the Off state.

Turning initially toFIG.1, electrical switches10may be mounted in a cabinet and used to control industrial equipment. Group installation allows multiple motors15or other loads to be connected to a single branch circuit protection device20. A power supply25supplies power to the branch circuit protection device20, and power is distributed from the branch circuit protection device20to each of the branch circuits. According to the illustrated embodiment, each branch circuit includes a circuit breaker10and a contactor30connected between the branch circuit protection device20and a motor15. Each circuit breaker10is configured to be manually actuated while each contactor30is configured to be electronically actuated.

As illustrated inFIGS.2and3, the circuit breaker is an electrical switch10including a housing35with an opening extending through a front surface of the housing. A rotary actuator40extends through the opening, providing a switch handle45external to the housing35. The switch handle45is rotatable between an Off position41and an On position43. An additional, Trip position42is located between the Off position41and the On position43, providing an indication to a technician when the circuit breaker has tripped. An inner rotational member47couples to the switch handle45and receives a force applied to the switch handle. Rotation of the switch handle45between the Off position41and the On position43similarly causes the inner rotational member47to transition between a first position and a second position. The inner rotational member47engages a mechanical linkage50(seeFIG.4) which, in turn, causes the contacts55in the circuit breaker to selectively open and close in the Off and On positions, respectively.

With reference next toFIGS.4and5, one embodiment of the circuit breaker10is illustrated in an Off state (FIG.4) and an On state (FIG.5). The mechanical linkage50includes a gear65which is rotatably mounted within the switch. The gear65includes a single gap67configured to receive a complementary tooth49extending from the inner rotational member47of the rotary actuator. It is another aspect of the invention, that the tooth and gap may be mounted in an opposite configuration, such that a tooth (not shown) may extend from the gear65and engage a gap (not shown) on the inner rotational member47. In either configuration, rotation of the inner rotational member47in a first plane causes rotation of the gear65in a second plane. The gear65is mounted with an axis of rotation75orthogonal to an axis of rotation46of the rotary actuator. The engagement of the tooth49with the gap67translates the torque received by the rotary actuator about the first axis of rotation46to the gear65for rotation about the second axis of rotation75. A first opening69in the gear65is configured to receive a boss85from a transfer member70which is also rotatably mounted within the switch. A second opening68in the gear65is configured to align with an opening77(see alsoFIG.15) in the transfer member70. A mounting pin57(see alsoFIG.6) may be inserted through the openings68,77in the gear65and transfer member70, respectively, such that the gear and transfer member are rotatably mounted around the same axis of rotation75within the switch.

As further illustrated inFIG.6, a rocker arm110is still another rotational member mounted within the switch. The rocker arm110includes an opening115(see alsoFIG.7) which may also be aligned with the openings68,77in the gear65and transfer member70, respectively, such that the gear65, transfer member70, and rocker arm110are all mounted within the switch by the mounting pin57and each of the gear65, transfer member70, and rocker arm110rotate about the same axis of rotation75. As will be discussed in more detail below, the transfer member70is configured to engage the rocker arm110as the transfer member70rotates between an Off position and an On position. Rotation of the transfer member70, in turn, causes rotation of the rocker arm110. The rocker arm110engages a lever arm150pivotally mounted within the switch.

The switch10also includes a plunger60configured to move reciprocally, back-and-forth, along an axis56. According to the illustrated embodiment shown inFIGS.4and5, the switch10is a three-phase switch, where a plunger60moves three prongs up and down in three parallel axes56A,56B,56C. A first end of the plunger60engages an end154of the lever arm150and a second end of the plunger includes each of the three prongs to reciprocally move a lower contact55B along the respective axis56. It is contemplated that the end of the prong may fit into a plunger seat or, optionally directly engage the lower contact55B. As the plunger60is moved in a downward direction, the lower contact55B separates from the upper contact55A, opening the circuit and putting the switch into the Off state. As the plunger60moves in an upward direction, the lower contact55B engages the upper contact55A, establishing an electrical connection between the contacts55and putting the switch into the On state.

The illustrated plunger60is intended to be exemplary only. It is contemplated that multiple plungers60may be mechanically connected or formed as a single member to open and close multiple contacts55in tandem. It is further contemplated that the geometry of the plunger60may take other forms or the plunger60may include an offset segment along the length of the plunger such that a force is applied at a first end of the plunger60along a first axis and the second end of the plunger60moves reciprocally along a second axis where the second axis is parallel to but offset from the first axis.

Although illustrated as a circuit breaker, the rotary actuator40and mechanical linkage50may be implemented on other switching devices such as a motor protection circuit, an electrical contactor, or the like. Terms such as upper, lower, inner, outer, front, rear, left, right, and the like will be used herein with respect to the illustrated switching device10. These terms are relational with respect to the illustrated switching device and are not intended to be limiting. It is understood that the switching device10may be installed in different orientations, such as vertical or horizontal, or may be rotated one hundred eighty degrees without deviating from the scope of the invention.

Turning next toFIGS.14-18, one embodiment of a transfer member70is illustrated. The transfer member70has a first side71and a second side73opposite the first side. The transfer member70has an irregular geometric outer periphery79with generally arcuate surfaces extending between the first and second sides. A first boss protrudes for a first length74from the first side71, and a second boss76protrudes for a second length78from the first side71. The second length78is greater than the first length74. The first and second bosses72,76are positioned on the first side such that they engage an elongated slot120(see alsoFIG.24) in the rocker arm110when the transfer member70and rocker arm110are mounted within the switch10. The first boss72and the second boss76are also referred to herein as coupling portions of the transfer member, and the elongated slot120is a complementary coupling portion on the rocker arm110configured to receive the bosses72,76at least partly within the slot120. According to the illustrated embodiment, the first boss72and the second boss76are generally cylindrical. The elongated slot120on the transfer member70has an arcuate profile such that the bosses72,76may slide within the slot120. It is contemplated that other geometrical shapes may be utilized as long as the shape of the boss72,76and the shape of the slot120are complementary such that the boss72,76may be inserted and/or removed from the slot as will be discussed further below. The transfer member70also includes a third boss80projecting from the first side71. The third boss80is referred to herein as an engagement member. The third boss80further includes an engagement surface81which is sloped with respect to an edge of the lever arm150with which it will engage. The transfer member70further includes a fourth boss85extending from the second side73. According to the illustrated embodiment, the fourth boss85is generally cylindrical and is configured to slidably engage the opening69in the gear65. Optionally, the fourth boss85may have other geometric shapes as long as the opening69in the gear65has a complementary geometry in which the fourth boss85may be slidably received.

Turning next toFIGS.19-23, one embodiment of a lever arm150is illustrated. The lever arm150has a first side160and a second side162, where the second side is opposite the first side. The lever arm150has an irregular geometric periphery extending between the first and second sides160,162. According to the illustrated embodiment, the lever arm150is formed as a single member but will be descried herein as three different segments. A first segment is the upper portion155, a second segment is the middle portion151, and a third segment is the lower portion153. The upper portion155of the lever arm150is generally hook-shaped. The lever arm150extends upward from the middle portion151toward a first end152of the lever arm. At the first end152of the lever arm150, the upper portion155curls back on itself forming the hook portion of the lever arm. A recess-portion163extends along a portion of the second side162of the lever arm at the first end152before the upper portion155bends back toward the middle portion151. At an end164of the hook portion, an engagement member165protrudes from the first side160of the upper portion155. According to the illustrated embodiment, the engagement member165is generally cylindrical and extends from the first side160a sufficient distance to engage with the rocker arm110, as will be discussed in more detail below. The middle portion151of the lever arm150includes a pivotal mount157protruding from the second side162of the lever arm. The pivotal mount157is fit through an opening in a side plate (not shown) of the switch and a pin or clip is used to secure the lever arm150to the side plate. The lever arm150pivots about the pivotal mount157within the switch10as it moves between an Off state and an On state. The lower portion153of the lever arm is an elongated member and is configured to engage a plunger within the switch. In an Off state, the lower portion153holds the plunger in a down, or extended position, such that the contacts55in the switch are open. In the On state, the lower portion153releases the plunger and springs in the switch push the plunger upward, or in a retracted position, such that the contacts55in the switch close, establishing an electrical connection between upper contacts55A an lower contacts55B.

Turning next toFIGS.24-27, one embodiment of a rocker arm110is illustrated. The rocker arm110includes a body portion125and an elongated member130. The body portion125includes a first side126and a second side127, where the second side is opposite the first side. Similarly, the elongated member130includes a first side131and a second side132, where the second side is opposite the first side. The first side126of the body portion125is generally parallel to but offset from the first side131of the elongated member130. Similarly, the second side127of the body portion125is generally parallel to but offset from the second side132of the elongated member130. Each of the body portion125and the elongated member130have an irregular geometric outer periphery extending between the respective first and second sides. The outer periphery129of the body portion125has generally arcuate shapes and extends for a first width128between the first and second sides126,127. The outer periphery134of the of the elongated member has a first generally planar segment and a second generally planar segment extending away from the body portion125, where the width between the first and second generally planar segments is greater proximate the body portion125and tapers toward an end135distal from the body portion. The end135distal from the body portion is generally arcuate in shape. The elongated member130has a second width133, where the second width133is less than the first width128. The body portion125further includes the opening115extending therethrough by which the rocker arm110is mounted within the switch10. The elongated member130includes a second opening137extending therethrough near the end135distal from the body portion125. The second opening137is configured to be coupled to an arm190, as seen inFIG.13.

Turning next toFIGS.28-31, another embodiment of the circuit breaker is illustrated in the OFF state. The mechanical linkage250includes a gear265which is rotatably mounted within the switch. The gear265includes an opening268through which a mounting pin257is inserted and about which the gear265rotates. The gear265includes a single gap267configured to receive a complementary tooth49extending from the inner rotational member47of the rotary actuator40. It is another aspect of the invention, that the tooth and gap may be mounted in an opposite configuration, such that a tooth (not shown) may extend from the gear265and engage a gap (not shown) on the inner rotational member47. In either configuration, rotation of the inner rotational member47in a first plane causes rotation of the gear265in a second plane. The gear265is mounted with an axis of rotation75orthogonal to an axis of rotation46of the rotary actuator40. The engagement of the tooth49with the gap267translates the torque received by the rotary actuator40about the first axis of rotation46to the gear265for rotation about the second axis of rotation75. The gear265includes an elongated channel269configured to receive a transfer member270. The transfer member270is slidably mounted within the elongated channel269. The transfer member has a first end272oriented away from a rocker arm310and a second end274which selectively engages the rocker arm310.

The mechanical linkage250also includes the rocker arm310. The rocker arm310includes an opening315(see alsoFIG.38) which is aligned with the opening268in the gear265and configured to receive the mounting pin257. The gear265and rocker arm310are mounted within the switch by the mounting pin257, and both the gear265and rocker arm310rotate about the same axis of rotation75. As will be discussed in more detail below, the transfer member270, slidably mounted within the gear265, is configured to engage the rocker arm310as the gear265rotates between an Off position and an On position. Rotation of the gear265and engagement of the transfer member270, in turn, causes rotation of the rocker arm310. The rocker arm310engages a further mechanical linkage360to selectively activate a plunger60which, in turn, selectively opens and closes one or more contacts within the switch.

Turning next toFIG.32, another embodiment of the transfer member270is illustrated. The transfer member270has a generally cylindrically configuration. The transfer member270extends between the first end272and the second end274. A first portion271of the transfer member270has a first diameter, and a second portion273of the transfer member has a second diameter. The first diameter corresponds to a diameter of the elongated channel269in the gear265in which the transfer member270is mounted. The outer periphery of the first portion271of the transfer member270engages the inner periphery of the elongated channel269as the transfer member270slides within the elongated channel. The second diameter is less than the first diameter, such that a spring350(SeeFIG.41) may be mounted around the second portion273of the transfer member270within the elongated channel269of the gear265. A transition276between the first portion271and the second portion273provides a seat for a first end of the spring. A ring around the end of the elongated channel269proximate the second end274of the transfer member270provides a seat for a second end of the spring. When mounted within the elongated channel269, the spring applies a biasing force on the transfer member270in a direction toward the first end272of the transfer member270.

Turning next toFIGS.33-37, one embodiment of the gear265, which is configured to hold the transfer member270is illustrated. As previously discussed, the gear265includes an opening268through which a mounting pin257is inserted and about which the gear rotates. The gear265includes a gap267which acts as an engagement portion with the tooth49of the rotary actuator40. The elongated channel269acts as a coupling portion to slidably receive the transfer member270. According to the illustrated embodiment, the gear265extends between a first end281and a second end283. The gear265further includes an arcuate boss280protruding from the second end283.

Turning next toFIGS.38-40, another embodiment of the rocker arm310is illustrated. The rocker arm310includes an upper portion325and a lower portion330. The rocker arm310also includes a first side326and a second side327, where the second side is opposite the first side. The rocker arm310has an irregular geometric outer periphery extending between the respective first and second sides. As previously discussed, an opening315extends through the rocker arm310which is configured to receive the mounting pin257about which the rocker arm310rotates. The rocker arm310includes a second opening337extending therethrough near the lower portion of the rocker arm310. The second opening337is configured to be coupled to a further mechanical linkage, as seen inFIG.31. A recess340is located in the upper portion325of the rocker arm310, and the recess340is configured to receive the second end274of the transfer member270. An elongated slot345is also present in the upper portion325of the rocker arm310. The elongated slot345is arcuate and curves around the opening315for the mounting pin257. The elongated slot345is configured to receive the arcuate boss280from the gear265.

In operation, the transfer member70and rocker arm110work together to provide a switch10that provides for smoother operation over an extended range of motion of the rotary actuator40. Turning next toFIGS.8-13one embodiment of the mechanical linkage50within the switch10is illustrated in stages transitioning from an Off state to an On state. To start, the switch10is shown in an Off state (FIGS.8-9). The inner rotational member47of the rotary actuator40is in a first position, or the Off state. The tooth49extending downward is either not engaging the gap67of the gear65or may be positioned within the gap in the Off state. As the rotary actuator40begins turning, the tooth49engages the side wall of the gap67and begins to cause rotation of the gear65. The engagement of the tooth49from the rotary actuator40with the gear65is felt by the operator and begins transferring a first force applied to the rotary actuator to the mechanical linkage50. The transference of the first force between the rotary actuator and the mechanical linkage50begins at about twenty to thirty degrees of rotation, where ninety degrees of rotation completes the transition between states.

The gear65is initially coupled to the transfer member70and to the rocker arm110while in the Off state, such that rotation of the gear65from the Off state to the On state causes rotation of the transfer member70and the rocker arm110. The boss85, protruding from the second side73of the transfer member70, is inserted in the opening69of the gear65, creating a coupling between the transfer member70and the gear65. Rotation of the gear65causes rotation of the transfer member70. The first boss72and the second boss76, protruding from the first side71of the transfer member70, are each positioned within the slot120of the rocker arm110. As the transfer member70begins rotating in response to the rotation of the gear65, the first boss72engages a side of the slot120, causing rotation of the rocker arm110.

The transfer member70is slidably mounted within the switch10such that it may move axially back and forth between the gear65and the rocker arm110. As previously discussed, a mounting pin57extends through the gear65, transfer member70, and rocker arm110, providing a common axis of rotation75about which each of the three members rotates within the switch. According to the illustrated embodiment, a spring90is mounted around the mounting pin57and between the gear65and the transfer member70. The spring90applies a biasing force on the transfer member70, axially positioning the transfer member70towards the rocker arm110. It is contemplated that the spring90may be mounted, for example, on the boss85and between the transfer member70and gear65. Optionally, other types of springs, rather than the illustrated coil spring90, may be utilized to apply the biasing force on the transfer member70without deviating from the scope of the invention. The spring90applies a biasing force such that the first boss72of the transfer member70is initially located within the slot120of the rocker arm110.

As the transfer member70rotates, the engagement member80of the transfer member70contacts a complementary engagement portion of the lever arm150. More specifically, a tapered engagement surface81of the engagement member80contacts the first end152of the lever arm150. Continued rotation of the transfer member70causes the engagement surface81to slide down from the first end152and adjacent to the second side162of the lever arm150. The tapered engagement surface81allows for some variation in alignment of the transfer member70with the first end152of the lever arm150while still achieving successful engagement between surfaces. The tapered engagement surface81also causes the transfer member to compress the spring90and slide away from the rocker arm110along the axis of rotation75as the engagement member80rotates down to the second send162of the lever arm150. The transfer member70is slidably mounted on the mounting pin57and the boss85mounted on the second side73of the transfer member is slidably mounted within the opening69in the gear65. As the transfer member70slides away from the rocker arm110, the first boss72on the first side71of the transfer member exits the slot120and stops causing further rotation of the rocker arm110.

During rotation, the rocker arm110engages the lever arm150which, in turn, allows the contacts55on the switch10to close. As discussed above, rotation of the transfer member70will initially cause rotation of the rocker arm110due to the first boss72of the transfer member70engaging the slot120of the rocker arm. As the rocker arm110rotates about the axis of rotation75, the elongated member130engages the engagement member165of the lever arm150. The lever arm150pivots around the pivotal mount157. As the second end154of the lever arm150moves from the Off position to the On position, the plunger60is released and the contacts55close. The contacts close when the rotary actuator40has completed greater than eighty degrees of rotation. Thus, rotation of the rotary actuator40in a first direction spreads out actuation of the switch from about twenty to thirty degrees of rotation to over eighty degrees of rotation, while still providing for a quick closure of the contacts55due to the spring force applied against the plunger60. The primary force required by the switch10to transition from the Off state to the On state occurs, therefore, over a range of fifty to sixty degrees of rotation in the first direction. In the ON state, the mechanical linkage50is in a stable position, allowing the mechanical linkage50to remain in the ON state until a second force is applied in the opposite direction.

To turn the switch Off, the second force is applied to the rotary actuator40in the opposite direction. As the rotary actuator40begins rotating in the opposite direction, the tooth49again engages the gap67of the gear65. As illustrated inFIG.7, the gear65includes a boss66protruding toward the rocker arm110as well. This boss66extends past the transfer member70and is configured to slide within the elongated slot120of the rocker arm110. The gear65and the transfer member70are configured to rotate in tandem as a result of the boss85on the transfer member slidably engaging the opening69in the gear65. It is contemplated, therefore, that the transfer member70may be configured to extend further in the direction of the boss66from the gear65and include an additional boss to replace the boss66from the gear65. In either embodiment, the boss66(as illustrated) or an additional boss from the transfer member is configured to engage the opposite end of the slot120used to turn the switch On. The boss66transfers the second force from the gear65to the rocker arm110to begin rotation of the rocker arm110from the On position to the Off position.

As the rocker arm110begins rotating from the On position to the Off position, the elongated member130of the rocker arm110no longer applies a force against the engagement member165of the lever arm150. A spring200is mounted to the lower portion153of the rocker arm150applying a biasing force to the rocker arm110toward the Off position. The spring200causes the engagement member165of the rocker arm110to follow the elongated member130as the elongated member is rotated away from the rocker arm110. After the rocker arm110and lever arm150rotate a short distance, the mechanical linkage50passes a stable position, such that additional springs and the corresponding spring forces within the switch10cause the lever arm150and rocker arm110to jump back to the Off state. The jump also causes the lever arm150to force the plunger60downward, separating the contacts55in the switch10and putting the switch back in the Off state. This jump occurs when the rotary actuator40has reached about the same position at which the contacts55close or slightly before the rotary actuator has returned to the eighty degree position. The primary force required by the switch10to transition from the On state to the Off state occurs, therefore, over about ten degrees of rotation in the second direction.

As the rotary actuator40continues turning back to the full Off position, the gear65continues turning the transfer member70back to the off position. The first boss72of the transfer member70is biased against the second side127of the body portion125of the rocker arm110by the spring90. The first boss72slides along the second side127until it again reaches the slot120. The spring90forces the transfer member70away from the gear65and toward the rocker arm110causing the first boss72to again engage the slot120on the rocker arm.

Turning next toFIGS.28-31another embodiment of the mechanical linkage250within the switch10is illustrated in the Off state. The inner rotational member47of the rotary actuator40is in a first position, or the Off state. The tooth49extending downward is either not engaging the gap267of the gear265or may be positioned within the gap in the Off state. As the rotary actuator40begins turning, the tooth49engages the side wall of the gap267and begins to cause rotation of the gear265. The engagement of the tooth49from the rotary actuator40with the gear265is felt by the operator and begins transferring a first force applied to the rotary actuator to the mechanical linkage250. The transference of the first force between the rotary actuator and the mechanical linkage250begins at about twenty to thirty degrees of rotation, where ninety degrees of rotation completes the transition between states.

The transfer member270is slidably mounted within the gear265. In the Off state, the first end272of the transfer member270engages an interference member290. The interference member290applies a force to the first end272of the transfer member270that is sufficient to overcome the biasing force from the spring350mounted within the elongated channel269of the gear265. The interference member290causes the transfer member270to slide toward the rocker arm310, inserting the second end274of the transfer member270into the recess340on the rocker arm. According to the illustrated embodiment, the interference member290is a flat spring. The force applied by the flat spring exceeds the force applied by the coil spring350, causing the transfer member270to slide toward the rocker arm310and compressing the coil spring350. Optionally, a rigid member may be utilized for the interference member290, where the rigid member has an angled form similar to that seen in the top view ofFIG.29. The transfer member270couples the gear265to the rocker arm310in the OFF state. Consequently, as the gear265begins rotation from the OFF state to the ON state, the rocker arm310similarly begins rotation between the OFF state and the ON state.

As the gear265rotates, the first end272of the transfer member270rotates along the interference member290. As seen inFIG.29, the interference member290has a first end292and a second end294. The first end292of the interference member is located proximate the first end272of the transfer member in the OFF state. As the gear265rotates, the transfer member270travels along the interference member290from the first end292toward the second end294. The interference member290has a first bend291proximate the first end292and a second bend293proximate the second end294. The interference member290is shaped such that the surface of the interference member290is angled away from the gear265between the first bend291and the second bend293. As a result, the interference member290allows the spring350within the elongated channel269to slide the transfer member270away from the rocker arm310during rotation of the gear265and rocker arm310. After the gear265and rocker arm310have reached the ON state, the first end272of the transfer member270either no longer engages the interference member290or the displacement of the second end294of the interference member from the rocker arm310is sufficient to allow the second end274of the transfer member270to be completely removed from the recess340in the rocker arm310, and the transfer member270no longer transfers force from the gear265to the rocker arm310.

During rotation, the rocker arm310engages a further mechanical linkage360which, in turn, allows the contacts55on the switch10to close. As discussed above, rotation of the transfer member270will initially cause rotation of the rocker arm310due to the transfer member270engaging the recess340of the rocker arm. As the rocker arm310rotates about the axis of rotation75, the lower portion330of the rocker arm310pivots around the mounting opening315. The second opening337proximate the lower end of the rocker arm310serves as an engagement portion of the rocker arm310and is coupled to the additional mechanical linkage360. Rather than a single lever arm150, as discussed above with respect to one embodiment of the invention, multiple linkages are pivotally or slidably connected to transfer the force from the rocker arm310to the plunger60. A linking member of the additional mechanical linkage360is fixedly, and pivotally mounted within the second opening337to serve as an engagement portion of the additional mechanical linkage360. Rotation of the lower portion330of the rocker arm310causes one end of the linking member to move right and the other end of the linking member to rotate downward to engage a lever arm, which, in turn, engages the plunger60. When the rocker arm310reaches the On state, the additional mechanical linkage360has allowed the plunger60to release and the contacts55within the switch10to close. The contacts close when the rotary actuator40has completed greater than eighty degrees of rotation. Thus, rotation of the rotary actuator40in a first direction spreads out actuation of the switch from about twenty to thirty degrees of rotation to over eighty degrees of rotation, while still providing for a quick closure of the contacts55due to the spring force applied against the plunger60. The primary force required by the switch10to transition from the Off state to the On state occurs, therefore, over a range of fifty to sixty degrees of rotation in the first direction. In the ON state, the mechanical linkage250is in a stable position, allowing the mechanical linkage250to remain in the ON state until a second force is applied in the opposite direction.

To turn the switch Off, the second force is applied to the rotary actuator40in the opposite direction. As the rotary actuator40begins rotating in the opposite direction, the tooth49again engages the gap267of the gear265. The arcuate boss280of the gear265is positioned within the arcuate slot345of the rocker arm310. One end of the arcuate boss280engages a side wall of the arcuate slot345, transferring the second force from the gear265to the rocker arm310to begin rotation of the rocker arm310from the On position to the Off position. As the rocker arm310begins rotating from the On position to the Off position, the lower portion330of the rocker arm310pivots away from the additional mechanical linkage360. Further, because the second opening337is coupled to the additional mechanical linkage360, the rocker arm310causes the additional mechanical linkage to begin returning to the Off position. One or more springs connected to the additional mechanical linkage360apply a biasing force on the mechanical linkage360to return to the Off position. After the gear367and rocker arm310rotate a short distance, the rocker arm310draws the additional mechanical linkage360past a stable position, such that the additional springs and the corresponding spring forces within the switch10cause the additional mechanical linkage360and the rocker arm310, connected to the additional mechanical linkage, to jump back to the Off state. The jump also forces the plunger60downward, separating the contacts55in the switch10and putting the switch back in the Off state. This jump occurs when the rotary actuator40has reached about the same position at which the contacts55close or slightly before the rotary actuator has returned to the eighty degree position. The primary force required by the switch10to transition from the On state to the Off state occurs, therefore, over about ten degrees of rotation in the second direction.

As the rotary actuator40continues turning back to the full Off position, the gear265continues turning toward the Off position. The second end274of the transfer member270slides along the first side326of the rocker arm310. The first end272of the transfer member270engages the interference member290causing compression of the spring350in the elongated channel269. The second end274of the transfer member270continues to slide along the first side326of the rocker arm310until the transfer member270is again positioned in front of the recess340in the rocker arm310. The second end374of the transfer member270then slides into the recess340on the rocker arm310returning the switch to the Off position.