Patent ID: 12217918

DETAILED DESCRIPTION OF THE DISCLOSURE

Exemplary embodiments of fusible disconnect switch devices are described below with enhanced features for high current industrial power supplies. Method aspects will be in part apparent and in part explicitly discussed in the description below.

FIGS.1A and1Bshow an exemplary fusible disconnect switch device50.FIG.1Ais a perspective view of the disconnect switch device50andFIG.1Bis a similar view of the disconnect switch device50without a fuse module54installed, revealing internal components of the disconnect switch device50. In the exemplary embodiment, the disconnect switch device50includes a non-conductive switch housing52configured or adapted to receive a retractable rectangular touch-safe power fuse module54. The fuse module54is similar in some aspects to a CUBEFuse™ power fuse module commercially available from Bussmann by Eaton of St. Louis, Missouri. The fuse module54is configured, however, for higher current industrial power applications than previously available CUBEFuse™ power fuse modules are capable of meeting. In contemplated examples the fuse module54may have a voltage rating of 500 VDC and an ampacity rating in contemplated examples of 400 A or 600 A. The switch housing52and the disconnect switch device50are likewise designed to handle such high current applications, including but not limited to an improved switching mechanism described below to more capably meet the needs of high current industrial power systems.

In the exemplary embodiment, a line side fuse clip60(FIG.1B) may be situated within the switch housing52and may receive one of the terminal blades (not shown) of the fuse module54. A load side fuse clip62may also be situated within the switch housing52and may receive the other of the fuse terminal blades (not shown). The line side fuse clip60may be electrically connected to a line side terminal63including a stationary contact64. The load side fuse clip62may be electrically connected to a load side terminal66.

A rotary switch actuator68is further provided on the switch housing52, and is formed with a lever69that protrudes from the switch housing52for manual positioning of the switch actuator68between the operating positions described below to open and close the switch assembly200including movable contacts74,76(seeFIG.2). The switch actuator68is mechanically coupled to one end of a link70and an actuator bias element101via a projecting arm71extending radially away from a round main body of the switch actuator68. The round body is mounted in the switch housing52for rotation about its center axis to operate the switch mechanism.

The link70, at its other end, is in turn coupled to a slider assembly72. The slider assembly72carries a pair of movable contacts74and76. Another stationary contact80(seeFIG.2) electrically connected to the line side terminal63is also provided. Electrical connection to power supply circuitry may be made to the line side terminal63, and electrical connection to load side circuitry may be made to the load side terminal66in a known manner. A variety of connecting techniques are known (e.g., screw clamp terminals, box lug terminals, bolted connections, terminal stud connections, bus bar connections, and the like) and may be utilized to establish the line and load side connections to external circuitry to be protected by the fuse module54.

Disconnect switching may be accomplished by grasping the lever69and rotating the switch actuator68from an “off” or “opened” position in the direction of arrow A, causing the actuator bias element101to move and then causing the link70to move the slider assembly72linearly in the direction of arrow B in sequential stages of actuation explained further below, and ultimately moving the switch contacts74and76toward the stationary contacts64and80. Eventually, the switch mechanism closes when the contacts74and76become mechanically and electrically engaged to the stationary contacts64and80. With the switch mechanism closed, the circuit path through the fuse module54between the line and load side terminals63and66is completed when the fuse terminal blades are received in the line and load side fuse clips60and62.

When the lever69is moved to rotate the switch actuator68in the opposite direction indicated by arrow C, the actuator bias element101moves and causes the link70to move, which causes the slider assembly72to move linearly in the direction of arrow D in sequential stages of actuation explained further below, and ultimately pull the switch contacts74and76away from the stationary contacts64and80to open the circuit path through the fuse module54. As such, by moving the switch actuator68to a desired position with the lever69, the fuse module54and associated load side circuitry may be connected and disconnected from the line side circuitry while the line side circuitry remains “live” in full power operation. As seen inFIGS.1A and1B, the switch actuator68is configured with a square internal bore that may receive an external shaft such that the switch actuator68may be remotely rotated in an automatic manner. In still other embodiments, the switch housing52may include an internal trip mechanism causing the switch actuator68to rotate if certain current conditions are detected and therefore prevent the fuse module54from opening. Current detection and control circuitry may optionally be provided to operate the trip mechanism when provided.

The fuse module54may also be simply plugged into the fuse clips60,62or extracted therefrom to install or remove the fuse module54from the switch housing52. The fuse housing56projects from the switch housing52and is accessible from the exterior of the switch housing52so that a person can grasp the handle59and pull it in the direction of arrow D to disengage the fuse terminal blades from the line and load side fuse clips60and62such that the fuse module54is completely released from the switch housing52. Likewise, a replacement fuse module54can be grasped by hand and moved toward the switch housing52in the direction of Arrow B to engage the fuse terminal blades to the line and load side fuse clips60and62. Such plug-in connection and removal of the fuse module54advantageously facilitates quick and convenient installation and removal of the fuse module54without requiring separately supplied fuse carrier elements and without requiring tools or fasteners common to other known fusible disconnect switch devices.

Additionally, the disconnect switch device50is rather compact and can easily occupy less space in a fusible panelboard assembly, for example, than conventional in-line fuse and circuit breaker combinations. In particular, the fuse module54occupies a smaller area, sometimes referred to as a footprint, in the panel assembly than non-rectangular fuses having comparable ratings and interruption capabilities. Reductions in the size of panelboards are therefore possible, with increased interruption capabilities. In one example, the overall footprint of the disconnect switch device50is approximately 40% to 50% of a known disconnect switch device of the same current rating.

In ordinary use, the circuit is preferably connected and disconnected at the switch contacts64,74,76and80rather than at the fuse clips. Electrical arcing that may occur when connecting/disconnecting the circuit may be contained at a location away from the fuse clips to provide additional safety for persons installing, removing, or replacing fuses. By opening the disconnect switch device50with the switch actuator68before installing or removing the fuse module54, any risk posed by electrical arcing or energized metal at the fuse module and housing interface is eliminated. The fusible disconnect switch device50is accordingly believed to be safer to use than many known fused disconnect switches.

The fusible disconnect switch device50includes further features such as a safety cover92driven by an interlock element90that is coupled to the switch actuator68, which improves the safety of the disconnect switch device50in the event that a person attempts to install the fuse module54without first operating the switch actuator68to disconnect the circuit through the fuse module54. An interlock shaft96may be used to prevent a person from attempting to remove the fuse module54without first operating the switch actuator68to disconnect the circuit through the fuse module54.

With the increased rating, the arcing energy between the movable contacts74,76and the stationary contacts64,80may be increased. To eliminate arcing of increased energy, the distance between the movable contacts74,76and the stationary contacts64,80may be increased such that the number of arc plates (not shown) may be increased in an arc chute150(seeFIG.1B). Further, a metal sheet148may be soldered on the contacts74,76,64,80and terminals63,66to help dissipate the heat. The metal sheet may be made of copper, aluminum, or other metal that enables the disconnect switch device50to function as described herein. In one example, the amount of copper placed around the contacts74,76,64,80and terminals63,66is approximately three times more than a known disconnect switch device of the same current rating.

FIG.2is an enlarged view of the switch assembly200included in the disconnect switch device50. In the exemplary embodiment, the switch assembly200includes the switch actuator68, the actuator bias element101, and the slider assembly72. The actuator bias element101is rotatably coupled to the switch actuator68at a joint204. The slider assembly72is linked to the switch actuator68and the actuator bias element101at the joint204via the link70. The slider assembly72and the actuator bias element101are responsive to the position of the switch actuator68to effect a switch closing operation or a switch opening operation.

In the exemplary embodiment, the actuator bias element101is a coil spring. The actuator bias element101includes a first end206and a second end208opposite the first end206. The first end206of the actuator bias element101acts on the switch actuator68. The second end208of the actuator bias element101may be coupled to the switch housing52. In one example, the second end208is attached to a bar209. The bar209is coupled to the switch housing52by being inserted into a hole (not shown) formed in the switch housing52. In some embodiments, a shaft210is included for the actuator bias element101to wind around. The shaft210provides a structural support for the actuator bias element101such that the actuator bias element101slides along the shaft210when the actuator bias element101compresses or decompresses.

In the exemplary embodiment, the link70includes a first end212and a second end214opposite the first end212. The first end212is coupled to the switch actuator68and the actuator bias element101. The second end214is coupled to the slider assembly72. The link70further includes a link slot216. The link slot216may be elongated and oriented generally parallel to the longitudinal axis of the link70. The link slot216may be positioned proximate the first end212of the link70. The link slot216includes a first end215and a second end217that is opposite the first end215and further away from the first end212of the link70than the first end of215. In some embodiments, the link70is coupled to the joint204, with the joint204extending through the link slot216. During the opening and closing operation of the disconnect switch device50, the link70slides along the link slot216between the first end215and the second end217. The link70may be made of metal, such as steel, copper, or other material that enables the link70to function as described herein.

In some embodiments, the switch assembly200includes two links70(seeFIG.1B). The links70are positioned on opposite sides of the actuator bias element101. The dual-link configuration ensures the forces from the actuator bias element101upon the switch actuator68and upon the slider assembly72is balanced. The dual-link configuration also divides the impact of the swift motion of the slider assembly72on the links70.

In operation, the rotation of the switch actuator68causes the joint204to slide in the link slot216and the actuator bias element101to pivot about the second end208of the actuator bias element101. While pivoting, the actuator bias element101compresses and stores energy, or decompresses and releases energy. During the downward motion of the joint204, when the joint204reaches the second end217of the link slot216, the joint204engages the link70and the combined force from the actuator bias element101and the switch actuator68is applied to the link70and further to the slider assembly72. During the upward motion of the joint204, when the joint204reaches the first end215of the link slot216, the joint204engages the link70and the combined force from the actuator bias element101and the switch actuator68is applied to the link70and further to the slider assembly72. Accordingly, the actuator bias element101increases the force applied to the slider assembly72during the switch closing or opening operation. Further, because at first the joint204slides along the link slot216without engaging the link70, the force needed to initiate the closing or opening operation is reduced to a force needed to compress the actuator bias element101, instead of moving a part or the entirety of the slider assembly72. In addition, during the opening or closing operation, the impact of the operation momentum is focused on the link slot216. In a known disconnect switch device, a slot is position on the switch actuator68such as on the projecting arm71. Because the switch actuator68is made of insulated material such as plastic for safety reasons, the switch actuator68may not be strong enough to withstand the momentum from the high speed opening or closing and, as a result, the life of the disconnect switch device may be reduced. With the link slot216positioned on the link70, because the link may be made of more durable material like metal than the insulated material for the switch actuator68, the link70can withstand the impact from the operational momentum. Accordingly, the life of the disconnect switch device50is extended.

The slider assembly72includes a first or upper slider100and a second or lower slider102each slidably movable with respect to the switch housing52along a linear axis in the direction of arrows B and D. That is, in the example shown the first and second sliders100,102are respectively movable along coincident linear axes. The first slider100further is independently movable relative to the second slider102. Specifically, the first slider100is movable relative to the second slider102in a first stage of opening and closing operations while the second slider remains stationary. The second slider102carries the movable contacts74,76to make or break an electrical connection with the stationary contacts64,80and is moved by the first slider100in a second stage of the switch closing and opening operations.

The first slider100is biased by a pair of bias elements104,106on either side of a first end of the first slider100. One end110of the bias element104is coupled to the first slider100. The other end116of the bias element104is coupled to the switch housing52. In between the ends110,116the bias element104includes a helical compression spring portion120.

The bias element106is substantially identically formed as the bias element104shown and is similarly connected to the first slider100and the switch housing52. Because the first slider100is movable in the direction of arrows B and D along the linear axis, the bias elements104,106, which are mechanically connected to the first slider100, pivot about their ends as the first slider100is moved, while the opposing ends of the bias elements104,106are held in place. The pivotal mounting of the bias elements104,106allows them to store and release force and energy to facilitate opening and closing of the switch contacts74,76as they are pivoted to different positions. In some embodiments, similar to the actuator bias element101, a shaft210is provided such that the bias element104,106winds around the shaft210. The bias element104,106may be coupled to the switch housing52via a bar209.

The first slider100may be formed from a plastic material known in the art. In the exemplary embodiment, the first slider100includes a body218and two arms220extending from the body218. The arms220may extend perpendicularly from the body218. Each of the bias elements104,106are coupled to the first slider100at one of the arms220. The link70may be rotatably coupled to the first slider at a midpoint226of the first end of the first slider100.

In the exemplary embodiment, the body218of the first slider100further includes at least one slider slot228. The slider slot228may be oriented longitudinally along the body218. In some embodiments, two slider slots228are included in the body218. The two slider slots228may be parallel to one another.

The second slider102may also be formed from a plastic material known in the art. In the exemplary embodiment, the second slider102includes a body230and arms232. The arm232extends longitudinally away from an end233of the body230. At the end of the arm232, a bar234is coupled to the arms232. At least one pin236is positioned on the bar234. In some embodiments, the second slider102includes a pair of pins236. The pin236is slidably coupled to the first slider100in the slider slot228such that the pin236slides along the slider slot228during the opening and closing operation of the disconnect switch device50. Proximate to the end233of the body230, the second slider102carries at least one movable contact74,76toward or away from the stationary contact64,80to make or break an electrical connection at the line side terminal63and/or the load side terminal66(seeFIG.1B). In some embodiments, the disconnect switch device50includes a pair of stationary contacts64and a pair of movable contacts74for the line side terminal63, and similarly, includes a pair of stationary contacts80and a pair of movable contacts76. This dual-contact configuration provides more secure electrical contact between the stationary contacts64,80and the movable contacts74,76than a single-contact configuration.

In the exemplary embodiment, the second slider102is coupled to ends of bias elements144,146proximate an end138of the second slider102. The bias elements144,146are coupled to the switch housing52at their other ends. In some embodiments, a shaft210is provided such that the bias element144,146winds around the shaft210. The bias element144,146may be coupled to the switch housing52via a bar209.

The switch closing operation is illustrated inFIGS.3A through3D.FIG.3Ashows a preparation stage of the closing operation. InFIG.3A, the switch actuator68is rotated in the direction of arrow A from the opened or off position302and the movable contacts74,76are separated from the stationary contacts64,80. The actuator bias element101starts to be compressed and stores energy. The joint204slides along the link slot216of the link70toward the link70. The first and second sliders100,102and their bias element104,106,144,146remain stationary during the preparation stage, and are mechanically isolated from the actuator bias element101. This isolation mechanism reduces the force needed to initiate the closing operation to a force needed to compress the actuator bias element101, instead of a force needed to move the first slider100or the entire slider assembly72.

InFIG.3B, the switch actuator68is further rotated in the direction of arrow A and a first stage of the switch closing operation is illustrated. In the first stage, the actuator bias element has reached its maximum compressed state, and starts to release its stored energy, pushing the joint204toward the second end214of the link70. In the first stage, the joint204has reached the end of the link slot216of the link70and pushes against the link70. That is, the switch actuator68and the actuator bias element101engage the link70and the first slider100and the combined force from the switch actuator68and the actuator bias element101is applied to the first slider100. The first slider100is moved downwardly in the direction of arrow B by the link70as the switch actuator68rotates and the actuator bias elements releases stored energy, while the second slider102is maintained stationary. The release of the stored energy in the actuator bias element101adds to the force applied on the first slider100, besides the force from the switch actuator68. Accordingly, the speed of the closing operation is increased, compared to a switch assembly that does not include an actuator bias element101. The bias elements104,106coupled to the first slider100are compressed and store energy as the first slider100descends. The descending first slider100also causes the bias elements104,106to pivot from their initial position shown inFIG.3A. The descending first slider100also causes the actuator bias element101to pivot further away from its initial position shown inFIG.3A. The second slider102and its bias elements144,146are mechanically isolated from the first slider100, however, and are not affected by this stage of operation. The mechanical isolation of the second slider102from the first slider100at the first stage reduces force needed to turn the switch actuator68, compared to a second slider being coupled to a first slider all the time. As a result, force needed for the first stage of the closing operation is the force needed to move the first slider100downward, instead of both the first and second sliders.

FIG.3Cillustrates a second stage of the switch closing operation. As the first slider100is descending, the actuator bias element101is being compressed and stores energy in the compression. The first slider100has now descended further and pushes against the send slider102at the end233of the body230of the second slider102. In this stage, the second slider102is driven by the first slider100and the second slider102moves with the first slider100. That is, the sliders100,102descend together in this stage. As the second slider102begins to move downwardly in the direction of arrow B, the bias elements144,146are compressed to store energy as well as pivoted as shown. The switch contacts74,76are carried downward with the second slider102toward the stationary contacts64,80. In the position shown inFIG.3C, the bias elements104,106coupled to the first slider100reach a maximum state of compression.

The pivoting bias elements104and106begin to decompress as they pivot past the point of equilibrium shown inFIG.3C. The actuator bias element101has not reached its maximum decompressed state and continues to release the stored force. Stored force in the springs as they decompress is released to drive the first slider100downward apart from rotation of the switch actuator68. Shortly after this begins to occur, the pivoting bias elements144,146connected to the second slider102reach their maximum state of compression and also begin to release stored force as they are further pivoted. The bias elements144,146thereafter also drive the second slider102downward. The combined release of force in the actuator bias element101and the bias elements104,106,144,146causes the switch contacts74,76to quickly and firmly close. The actuator bias element101increases the force pushing the slider assembly72and therefore the speed of the closing operation is increased. Because the first slider100is linked directly to the switch actuator68, the switch actuator68is moved to the fully closed position under force (FIG.4D). The switch mechanism closes with a secure, automatic snap action once the bias elements104,106,144,146move past their points of equilibrium. Such quick automatic closure is advantageous for high voltage, high current power systems that present severe arcing potential.

FIGS.4A through4Dillustrate the switch opening operation.FIG.4Ashows a preparation stage of the opening position. InFIG.4A, the switch actuator68is rotated in the direction of arrow C, starting from the closed position402. The switch contacts74,76are closed and the circuit path through them is completed. The actuator bias element101starts to be compressed and stores energy. The joint204slides along the link slot216of the link70toward the first end215of the link70. The first and second sliders100,102and their bias elements104,106,144,146remain stationary. At the preparation stage, the actuator bias element101is mechanically isolated from the first and second sliders100,102and their bias elements104,106,144,146. This isolation mechanism reduces the force needed to initiate the opening position to a force needed to compress the actuator bias element101, instead of a force needed to move the first slider100or the first and second sliders100,102.

FIG.4Bshows a first stage of the opening operation wherein the switch actuator68is further rotated in the direction of arrow C. The actuator bias element101has passed the maximum compressed point and the stored energy is released into a force pushing the switch actuator in the direction of arrow C. Accordingly, the speed of the opening operation in increased. Further, the joint204has reached the end of the link slot216of the link70such that the joint204, the actuator bias element101, and the switch actuator68engages the link70and the first slider100to move the first slider100. In the first stage, the first slider100is pulled upwardly in the direction of arrow D while the second slider102remains stationary. The bias elements104,106coupled to the first slider100are compressed and begin to store energy as they are pivoted from their initial position. The second slider102and its bias elements144,146are mechanically isolated from the first slider100and are not affected by this stage of operation. Again, this mechanical isolation is advantageous because the force needed for the first stage of the opening operation is the force needed to move the first slider100, instead of both the first and second sliders.

InFIG.4C, the switch actuator68is further rotated and the first slider100has been lifted an amount sufficient to the point where the pins236push against the body218of the first slider100at an end of the slider slot228. The second slider102engages the first slider100through the engagement of pins236with the body218of the first slider100. The first and second sliders100,102are now mechanically coupled and ascend together with the first slider100driving upward movement of the second slider102. The bias elements144,146connected to the second slider102are compressed and begin to store energy as they are pivoted from their initial position shown inFIG.4Awhen the second slider102begins to move.

As shown inFIG.4C, the actuator bias element101has not reached its maximum decompressed state and the bias elements104,106coupled to the first slider100have pivoted past the point of equilibrium. The actuator bias element101continues to release stored energy, and the bias element104,106are now releasing stored energy to force the first slider100upward and drive the switch contacts74,76away from the stationary contacts64,80. The released force on the first slider100accelerates the upward movement of the second slider102that is now engaged to the first slider100and causes the bias elements144,146connected to the second slider102to pivot past their points of equilibrium. As this happens, the bias element144,146also start to release stored energy to drive the second slider102upward and drive the switch contacts74,76away from the stationary contacts64,80with increased force. In this stage, all of the bias elements104,106,144,146and the actuator bias element101cooperate to drive the switch mechanism to the fully opened position.

The combined release of force in the actuator bias element101and the bias elements104,106,144,146causes the switch contacts74,76to quickly open and separate. Because the first slider100is linked directly to the switch actuator68, the switch actuator68is moved to the final opened position shown inFIG.4Dunder force. The switch mechanism opens with a secure, automatic snap action once the actuator bias element101and the bias elements104,106,144,146move past their points of equilibrium. Such quick automatic opening is advantageous for high voltage, high current power systems that present severe arcing potential.

At least one technical effect of the systems and methods described herein includes (a) increasing opening and/or closing speed of the switch disconnect device; (b) reducing the force needed to be applied to a switch actuator in the opening and/or closing operation; and (c) increasing the life expectancy of a switch actuator and the disconnect switch device.

The benefits of the inventive concepts described are now believed to have been amply illustrated in relation to the exemplary embodiments disclosed.

An embodiment of a fusible disconnect switch device is provided. The disconnect switch device includes a switch housing configured to accept a pluggable fuse module, and a line side terminal and a load side terminal in the switch housing. The disconnect switch device further includes a switch actuator, an actuator bias element, and a slider assembly. The switch actuator is selectively positionable between an opened position and a closed position. The actuator bias element includes a first end and a second end opposite the first end, the first end acting on the switch actuator and the second end coupled to the switch housing. The slider assembly is linked to the switch actuator. The slider assembly includes a first slider and a second slider each slidably movable with respect to the switch housing along a linear axis. The first slider is independently movable relative to the second slider. The second slider carries at least one switch contact to make or break an electrical connection to one of the line and load side terminals, a first bias element acting on the first slider and a second bias element acting on the second slider, and the second bias element is mechanically isolated from the switch actuator in a first stage of a switch closing operation. The actuator bias element and the slider assembly are responsive to the position of the switch actuator to effect the switch closing operation and a switch opening operation.

Optionally, the actuator bias element stores energy in a preparation stage of the switch closing operation and the actuator bias element releases energy in the first stage of the switch closing operation and a second stage of the switch closing operation. The actuator bias element stores energy in a preparation stage of the switch opening operation and the actuator bias element releases energy in a first stage of the switch opening operation and a second stage of the switch opening operation. The actuator bias element moves independently from the slider assembly, and the actuator bias element is mechanically isolated from the slider assembly and the slider assembly remains stationary during the preparation stage of a switch opening operation or the switch closing operation. The fusible disconnect switch device further includes a link connecting the switch actuator to the first slider, the link further including a link slot and slidably coupled to the switch actuator at the slider slot. The link is slidably coupled to the switch actuator and the actuator bias element at a joint between the switch actuator and the actuator bias element. The fusible disconnect switch device further includes a pair of links, the switch actuator slidably coupled to the pair of links at the link slot of each of the pair of links with the pair of links positioned on opposite sides of the actuator bias element. The first and second bias elements and the actuator bias element provide a closing force in the second stage of the switch closing operation.

As further options, the first and second bias elements and the actuator bias element provide an opening force in the second stage of the switch opening operation. The second slider further includes at least one pin configured to engage the first slider in the switch opening operation and the switch closing operation. The second slider includes a pair of pins. The first slider defines at least one slider slot receiving the at least one pin therein, the at least one pin slidably coupled to the first slider at the at least one slider slot, and the second slider engages the first slider at the second stage of the switch closing operation. The first slider defines a pair of slider slots positioned generally parallel to one another. The second slider includes a pair of pins, each of the pair of pins received in one of the pair of slider slots.

Another embodiment of a fusible disconnect switch device is provided. The fusible disconnect switch device includes a switch housing, a line side terminal and a load side terminal in the switch housing, a switch actuator, an actuator bias element, a slider assembly, and a first pair of bias elements. The switch housing is configured to accept a removable fuse. The switch actuator is selectively positioned between an opened position and a closed position. The actuator bias element includes a first end and a second end opposite the first end, the first end acting on the switch actuator, and the second end coupled to the housing. The slider assembly is linked to the switch actuator. The first pair of bias elements each has a first end and a second end, the first end of each of the first pair of bias elements coupled to the housing and the second end of each of the first pair of bias elements acting upon a respective one of opposing sides of the slider assembly. The first pair of bias elements are simultaneously compressed by the selective positioning of the slider assembly or simultaneously decompressed by the selective positioning of the slider assembly to cooperatively store and release energy to effect a switch closing operation or a switch opening operation. The actuator bias element and the slider assembly are responsive to the position of the switch actuator to effect a switch closing operation or a switch opening operation via selective positioning of at least one switch contact to make or break an electrical connection to the load side terminal.

Optionally, the fusible disconnect switch device further includes a link connecting the switch actuator to the slider assembly, the link further including a slider slot and slidably coupled to the switch actuator at the slider slot. During the preparation stage of the switch opening operation or the switch closing operation, the actuator bias element is mechanically isolated from the slider assembly and the slider assembly remains stationary.

One more embodiment of a fusible disconnect switch device is provided. The disconnect switch device includes a switch housing configured to accept a pluggable fuse module, and a line side terminal and a load side terminal in the switch housing. The disconnect switch device further includes a switch actuator, an actuator bias element, and a slider assembly. The switch actuator is selectively positionable between an opened position and a closed position. The actuator bias element including a first end and a second end opposite the first end, the first end acting on the switch actuator and the second end coupled to the switch housing. The slider assembly is linked to the switch actuator. The slider assembly includes a first slider and a second slider each slidably movable with respect the switch housing along a linear axis, the second slider carries at least one switch contact to make or break an electrical connection to one of the line and load side terminals, and the first slider is independently movable relative to the second slider. The actuator bias element and the slider assembly are responsive to the position of the switch actuator to effect a switch closing operation and a switch opening operation, and the actuator bias element stores energy in a preparation stage of the switch opening operation and the actuator bias element releases energy in a first stage of the switch closing operation and a second stage of the switch closing operation.

Optionally, the fusible disconnect switch device further includes a link connecting the switch actuator to the first slider, the link further including a slider slot and slidably coupled to the switch actuator at the slider slot. The actuator bias element is mechanically isolated from the slider assembly, and the actuator bias element moves independently from the slider assembly during the preparation stage of the switch opening operation or the switch closing operation. The first and second bias elements and the actuator bias element provide a closing force in the second stage of the switch closing operation.

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.