Patent Description:
Fuses are current-sensitive devices designed to serve as the intentional weak link in an electrical circuit. Fuses provide protection of discrete components or of complete circuits by reliably melting under current overload conditions. Fuses come in a variety of packages and ratings to suit to their intended application.

Single stud fuses, also known as battery terminal fuses, are a particular type of fuse package in which the fuse is attached to a device or circuitry by a threaded connection, such as a stud. The fuse includes a hole through which a single stud may be inserted to mechanically connect the fuse to the device or circuit. The studs are specially adapted, such as by being insulated or otherwise materially treated, so that they do not disrupt or become part of a current path through the fuses, ensuring that the single stud fuses operate as designed.

To use the single stud fuses, the specially treated stud is separated from the fuse, the fuse is attached to the circuit or device to be protected, the stud is inserted through the hole in the fuse. The special treatment of the stud ensures that current flows through the fuse and not through the stud when assembled.

There exist assemblies, such as disconnect switches and power distribution modules, which include studs, such as for connection to other circuitry or batteries. The studs of these assemblies are not specially treated as they are for the single stud fuse. Thus, adding the single stud fuse to these stud-based assemblies will render the fuse useless and unable to protect the circuitry of the assembly or of components connected to the circuitry.

The abstract of <CIT> relates to a circuit protection assembly (CPA) is disposed between a source of power and a circuit to be protected. The CPA comprises a mounting block having a bore extending therethrough and a recess cavity on a first surface of the mounting block. A post having a first end is disposed within the recess cavity and a body portion extends through the bore. The body portion configured to receive a terminal and the second end configured to receive a securing mechanism. A fuse having a centrally disposed aperture is configured to receive the body portion of the post and to receive the terminal for connection to a circuit to be protected. An insulator disposed on the terminal and disposed beneath the securing mechanism. The insulator configured to isolate the post from the terminal and the fuse while allowing the securing mechanism to apply an amount of torque.

This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter.

An exemplary embodiment of an electrical device assembly in accordance with the present disclosure may include an electrical device and a single stud fuse assembly. The electrical device has a first stud that is to be connected to a first terminal. A receiving hole designed for a second stud is found in a housing of the electrical device. Instead of having the second stud, however, a landing pad shaft of a landing pad is orbitally riveted into the receiving hole. The landing pad, which is part of the single stud fuse assembly, also features a stud base receptacle to which a stud base of an electrically isolated stud, also part of the single stud fuse assembly, is inserted. The single stud fuse assembly also includes a single stud fuse with a shaft receptacle, and a stud shaft of the electrically isolated stud is disposed through the shaft receptacle before being connected to a second terminal.

Another exemplary embodiment of an electrical device in accordance with the present disclosure may include first and second studs and first and second nuts. A terminal of a battery is to be placed over the first stud before securing the first nut. A busbar within a housing of the electrical device is connected to the first stud. The second nut and second stud are removed, leaving a pocket in the housing. The electrical device also features a landing pad with a landing pad shaft and a rectangular receptacle. The landing pad is orbital riveted into the pocket until the landing pad shaft is connected to the busbar. Finally, the electrical device features an electrically isolated stud, which includes both a stud shaft and a stud base. The stud base fits into a side opening of the rectangular receptacle and the stud shaft receives a single stud fuse and a second terminal of the battery.

An exemplary embodiment of an electrical device assembly in accordance with the present disclosure may include an electrical device and a fuse assembly The electrical device includes a first stud to be connected to a first terminal of a second electronic device, a receiving hole in a plastic housing, and a busbar. The busbar has first and second portions, with the first busbar portion being connected to the first stud. The fuse assembly includes a fuse, a landing pad shaft, and an electrically isolated stud. The fuse is in a rectangular cubic housing which has a fusing element along a side edge and a shaft receptacle centrally located in the housing. The landing pad shaft is connected to a stud base receptacle and the two parts are machined from a unitary metal piece made of electrically conductive material. The electrically isolated stud has a stud base that is to be slid into a side opening of the stud base receptacle. The landing pad shaft is disposed into the receiving hole until the second busbar portion is connected to the landing pad shaft.

An electrical device assembly and method to attach an isolated single stud fuse assembly to an electrical device are disclosed. The electrical device assembly consists of multiple studs or studs, one or more of which is replaced with the isolated single stud fuse. A separate conductive copper landing zone allows the terminal attached to the electrical device to get a good electrical connection while ensuring that the single stud fuse is able to protect the electrical device as well as circuitry connected to the electrical device. The steel stud inserts slide into the landing zone, which allows higher torque for connections than with solid copper one-piece studs. The landing pad assembly is orbital riveted into a plastic housing of the electrical device, locking the assembly into the housing permanently. Further, a much better sealing of the connection is made compared to using a steel stud going through a busbar. Electrical devices such as disconnect switches and power distribution modules, both of which include multiple studs, are good candidates for the electrical device assembly and method for connecting the single stud fuse assembly to the electrical device disclosed herein.

<FIG> are representative images of a disconnect switch <NUM> for electrical applications, according to the prior art. <FIG> is a perspective view and <FIG> is a bottom perspective view of the disconnect switch <NUM>, where the bottom perspective view is oriented in a direction orthogonal to the perspective view. Typically used in high power applications, the disconnect switch <NUM> is a double pole, single throw (DPST) type switch that isolates two circuits at one time, circuits with two different voltages, or both the positive and negative of the same circuit. The disconnect switch <NUM> may be used in industrial applications for heavy equipment, such as earth moving equipment. The disconnect switch <NUM> may be used, for example, as a safety device for immobilization of hazardous moving parts, to disable power when the vehicle is not in use or during maintenance, and to provide security against theft. The disconnect switch <NUM> is made of an engineered polymer construction to avoid rust and corrosion and is lever-actuated.

Four studs 102a, 102b, 102c, and 102d (collectively, "studs <NUM>") are used to make connection to up to two different circuits. Each stud <NUM> further includes a respective hex nut 104a, 104b, 104c, and 104d (collectively, "hex nuts <NUM>"), visible in <FIG>, for enabling the circuit connections. To connect the disconnect switch <NUM> to a circuit to be protected, such as a battery on an industrial vehicle, the hex nuts <NUM> associated with two of the studs <NUM> are removed for attachment of the studs to battery or power cables. The hex nuts <NUM> are then resecured on the respective studs102, enabling the disconnect switch <NUM> to become part of the closed circuit.

To aid in describing the disconnect switch <NUM>, four quadrants 106a, 106b, 106c, and 106d (collectively, "quadrants <NUM>") are visible in <FIG>, with the stud 102a and hex nut 104a being in quadrant 106a, stud 102b and hex nut 104b being in quadrant 106b, and so on. The disconnect switch <NUM> further includes a dual-position lever <NUM> for switching the disconnect switch ON or OFF.

As an illustrative example, suppose a circuit, such as a battery on an industrial vehicle, has one terminal connected to quadrant 106a and the other terminal connected to quadrant 106c. When the lever <NUM> is in one position, the stud 102a in quadrant 106a is connected to the stud 102c in quadrant 106c inside the disconnect switch <NUM>, causing a closed circuit in which the battery is operable (disconnect switch is ON). When the lever <NUM> is in a second position, the stud 102a in quadrant 106a is disconnected from the stud 102c in quadrant 106c inside the disconnect switch <NUM>, causing an open circuit in which the battery is disabled (disconnect switch is OFF).

The disconnect switch <NUM> also includes apertures <NUM> for receiving a lock, enabling the disconnect switch to be secured in either the ON or the OFF position. Particularly when locked in the OFF state, the disconnect switch <NUM> may be thought of as a protective device because it protects the vehicle or other electrical device that includes the circuit to which the disconnect switch is connected.

<FIG> are representative images of a power distribution module (PDM) <NUM> for electrical applications, according to the prior art. <FIG> is a perspective view of the PDM <NUM> including relays and fuses and <FIG> is a perspective view of the PDM <NUM> without the connected components. PDMs are installed in applications to ensure circuits are protected, controlled, and/or sensed. PDMs provide centralized, safe power distribution for many applications, and may include fuses, relays, circuit breakers, current sensing components, and Controller Area Network (CAN) and Local Interconnect Network (LIN) modules. Though PDMs are well-known on industrial applications, such as heavy-duty trucks and agricultural and construction equipment, the applications for PDMs are expanding, particularly in the automotive industry.

Three studs 202a, 202b, and 202c (collectively, "studs <NUM>") are used to make connection to up to two different circuits. The studs <NUM> for the PDM <NUM> happen to be M8-type studs. Each stud <NUM> further includes a respective hex nut 204a, 204b, and 204c (collectively, "hex nuts <NUM>"), visible in <FIG>, for enabling the circuit connections. The PDM <NUM> also includes caps 206a, 206b, and 206c (collectively, "caps <NUM>"), which cover the respective studs <NUM>. The stud 202a is a ground stud, with the respective cap 206a being indicated in a first color shade, while the studs 202b and 202c are power studs, with the respective caps 206b and 206c being indicated in a second color shade.

To connect the PDM <NUM> to a circuit to be protected, such as a battery on an industrial vehicle, the hex nuts <NUM> associated with two of the studs <NUM>, one of the studs being the ground stud 202a, are removed for attachment to battery terminals or power cables. The hex nuts <NUM> are then resecured on the respective studs <NUM>, enabling the PDM to become part of the closed circuit.

<FIG> shows multiple relays, with one relay <NUM> being indicated, and multiple fuses, with one fuse <NUM> being indicated. There are also multiple connectors, with one connector <NUM> being indicated. While the studs <NUM> connect the PDM <NUM> to battery or power cables, each connector establishes a connection between the PDM and other electrical circuits, such as inside a vehicle, of which there may be many, with the relays and fuses supporting those circuits.

As an illustrative example, suppose a circuit, such as a battery on an industrial vehicle, has one terminal connected to stud 202a (ground) and the other terminal connected to stud 202b (power), with the respective hex nuts <NUM> securing the terminals to the PDM <NUM>. The result is a closed circuit in which the PDM is connected to the battery. When the connector for the lighting circuit of the vehicle is inserted into one of the connectors, the fuses and relays of the PDM <NUM> are able to protect and enable the various lights within the vehicle. A second connector for the cooling system, a third connector for the transmission, and so on, can be connected to the PDM <NUM>, providing power, protection, and enablement to each of the different circuits. The PDM <NUM> thus provides a centralized, safe power distribution for the various electrical systems within the vehicle.

The disconnect switch <NUM> and the power distribution module <NUM> are examples of an electrical device that is part of an electrical circuit, to which connection is made by cables, harnesses, terminals, or the like, the electrical device having a hole to be blocked (and electrically connected) between a stud and a nut. It may be desirable for the electrical device, in one or more locations, to additionally be protected by a fuse. Single stud fuses feature a shaft receptacle (aperture) for receiving a specialized insulated stud. Typically, the insulated stud goes through a bus bar and the bus bar goes to a metal terminal known as a "landing zone". Such a path is very difficult to seal and so the electrical device may not have sufficient protection against water and/or dust. Further, the sizes of the stud used to connect the fuse to the electrical device is difficult to vary.

<FIG> is a representative drawing of a single stud fuse assembly <NUM>, according to exemplary embodiments. The single stud fuse assembly <NUM> features a metal terminal <NUM>, also known as a landing pad <NUM>, and an electrically isolated stud <NUM>, a single stud fuse <NUM>, an optional washer <NUM>, and a nut <NUM>. In an exemplary embodiment, the nut <NUM> is a hex nut. The landing pad <NUM> features a stud base receptacle <NUM> and a shaft <NUM>, known also herein as a landing pad shaft <NUM>.

The stud base receptacle <NUM> is shaped to receive a stud base <NUM> of the stud <NUM>. The stud base has an insulated portion 318a that surrounds a metal portion 318b (collectively, "stud base <NUM>"), as illustrated in the cross-sectional view of <FIG>, below. The landing pad <NUM> further includes a side opening <NUM>, revealing a hollow interior <NUM>, as well as an inset portion <NUM>. In exemplary embodiments, the shaft <NUM> and the stud base receptacle <NUM> of the metal terminal <NUM>, including the side opening <NUM> and the inset portion <NUM>, are machined from a unitary metal piece made of electrically conductive material, such as copper or a copper alloy.

The steel stud <NUM> features a shaft <NUM>, known also herein as a stud shaft <NUM>, which has a threaded portion <NUM>, an unthreaded portion <NUM>, an insulated portion <NUM>, an optional integrated washer <NUM>, and a base <NUM>. In addition to the insulated portion <NUM> of the shaft <NUM> being insulated, the optional integrated washer <NUM> and the stud base <NUM> are also insulated so as to isolate them from current transmitted through the single stud fuse <NUM>. Thus, the stud <NUM> may be thought of as an electrically isolated stud. In addition to providing insulation so as to prevent current flow through the stud <NUM>, the optional integrated washer <NUM> also helps to withstand pressure after the single stud fuse assembly <NUM> is secured to an electrical device, such as a disconnect switch (<FIG>) or power distribution module (<FIG>), by the nut <NUM>. In an alternative embodiment, the insulation of the stud base <NUM> is sufficient to prevent current flow through the stud <NUM> and to withstand high mechanical pressures during torque of the nut <NUM>. Thus, the stud <NUM> may be configured without the optional integrated washer <NUM>. Alternatively, the shaft <NUM> of the stud <NUM> can be secured by a nut having an integrated washer, such as a flange nut, a trilobate nut, or other type of nut that can be used without a washer. In an exemplary embodiment, the insulated components of the stud <NUM> are insulated using electrically insulating material, such as overmolded plastic, though other insulation materials may also be used.

In an exemplary embodiment, the stud base receptacle <NUM> is a rectangular cube shape of a first dimension. The hollow interior <NUM> is of a second dimension smaller than the first dimension. As indicated by the arrow in <FIG>, the stud base <NUM>, which is a third dimension, fits snugly into the hollow interior <NUM> of the stud base receptacle <NUM>. Thus, the second dimension is slightly greater than the third dimension, allowing the stud base <NUM> to fit into the hollow interior <NUM> via the side opening <NUM> of the stud base receptacle <NUM>. The inset portion <NUM> of the stud base receptacle <NUM> is disposed opposite the shaft <NUM>, and the shaft <NUM> of the stud <NUM> fits into the inset portion <NUM> as the stud base <NUM> is laterally presented into the stud base receptacle <NUM>.

Once inserted into the landing pad <NUM>, the insulated steel stud <NUM> may be captured or mechanically locked in the stud base receptacle <NUM>. In an exemplary embodiment, orbital riveting, a mechanical bottleneck, a secondary lock, or other means are employed to mechanically lock the stud <NUM> to the landing pad <NUM>.

The single stud fuse assembly <NUM> further includes the single stud fuse <NUM>, which has a cylindrically shaped shaft receptacle <NUM> for receiving the stud <NUM>. Both the unthreaded portion <NUM> and the insulated portion <NUM> of the shaft <NUM> are disposed within the shaft receptacle <NUM> of the single stud fuse <NUM>. In an exemplary embodiment, the shaft <NUM> is insulated from a bottom portion of the fuse terminal, ensuring that the stud <NUM> will not conduct the fuse element (not shown) within the fuse <NUM>. The insulation may be higher than is shown. In an exemplary embodiment, the threaded portion <NUM> of the shaft <NUM> extends to the top of the fuse <NUM>. In an exemplary embodiment, the insulating layer/portion <NUM> and the insulating washer <NUM> of the single stud fuse assembly <NUM> isolates the stud <NUM> from the fuse <NUM>.

Once inserted through the shaft receptacle <NUM>, the shaft 316will have enough clearance above the fuse <NUM> to receive a female pole (such as the power cable lug <NUM> <FIG> and <FIG>, below), harness, or other terminal device, though the power cable lug is not part of the single stud fuse assembly <NUM>. An optional washer <NUM> may be disposed over the power cable lug onto the shaft <NUM> of the stud <NUM>. Finally, the nut <NUM> is used to secure the components of the single stud fuse assembly <NUM>.

<FIG> and <FIG> are representative drawings of a device assembly <NUM> including the single stud fuse assembly <NUM> of <FIG> and a disconnect switch <NUM>, according to exemplary embodiments. <FIG> is a perspective view and <FIG> is an exploded perspective view of the device assembly <NUM>. The disconnect switch <NUM> is similar to the disconnect switch <NUM> (<FIG>), with one of the studs being replaced with the single stud fuse assembly <NUM>. The disconnect switch <NUM> is representative of an electrical device that is part of an electrical circuit to which connection is made using terminals, cables, harnesses, or the like, the electrical device including a hole to be blocked and electrically connected between a stud and a nut. The device assembly <NUM> introduces, in the middle of the connection, an electrical protection, by replacing each stud to be protected with a system consisting of a landing pad plus an insulated stud plus a fuse, in other words, the single stud fuse assembly <NUM>.

The disconnect switch <NUM> features three studs 402a, 402b, and 402c (collectively, "studs <NUM>"), each having an associated hex nut 404a, 404b (not shown), and 404c (collectively, "hex nuts <NUM>"). The disconnect switch <NUM> features four quadrants 406a, 406b, 406c, and 406d (collectively, "quadrants <NUM>"). The stud and hex nut of quadrant 406d are removed and replaced with the single stud fuse assembly <NUM>. A dual position lever <NUM> enables the disconnect switch <NUM> to be turned ON or OFF. Apertures <NUM> enable a locking mechanism to be attached so as to secure the disconnect switch <NUM> in either the ON or OFF position.

In <FIG>, the single stud fuse assembly <NUM> is shown secured to the disconnect switch <NUM>. The threaded stud <NUM> (not shown) of the landing pad <NUM> is disposed inside a cylindrical receiving hole or pocket (not shown) in the plastic housing <NUM> of the disconnect switch <NUM> in place of the stud and hex nuts that would otherwise occupy the quadrant 406d. The receiving hole or pocket may be cylindrical in shape and may be threaded or unthreaded. As a result, the stud base receptacle <NUM> fits into the rectangular cube-shaped quadrant 406d such that the receptacle is seated atop a horizontal surface <NUM> of the quadrant. Further, in an exemplary embodiment, the shaft <NUM> of the landing pad <NUM> is orbital riveted into the receiving hole or pocket of the plastic housing <NUM>, thus becoming an encapsulated pole inside the disconnect switch <NUM>.

The stud <NUM> includes the stud base <NUM> which fits into the stud base receptacle <NUM> of the landing pad <NUM>. The stud base <NUM> creates a steel stud insert that slides into the stud base receptacle <NUM>. Steel, whether stainless, nickel-plated, zinc-plated, and so on, has a much higher tensile strength than copper, allowing higher torque for connections than with solid copper one piece studs. The fuse <NUM> is then inserted onto the shaft <NUM> of the stud <NUM>, through the shaft receptacle <NUM>, such that the fuse is disposed over the stud base receptacle <NUM>.

Between the single stud fuse <NUM> and the optional washer <NUM> and hex nut <NUM> is a power cable lug <NUM>. The power cable lug <NUM> is not part of the single stud fuse assembly <NUM>, but is instead supplied by the customer. The power cable lug <NUM> features a cable lug aperture <NUM>, for diposing over the shaft <NUM> of the stud <NUM>, and a cable <NUM> for electrically connecting the disconnect switch <NUM> to other circuitry, such as a battery. In one embodiment, the optional washer <NUM> and hex nut <NUM> are then inserted onto the shaft <NUM> of the stud <NUM> and secured. In a second embodiment, the hex nut <NUM> without the optional washer is inserted onto the shaft <NUM> of the stud <NUM> and secured.

<FIG> is a cross-sectional view of the device assembly <NUM>, according to exemplary embodiments. The device assembly <NUM> features the disconnect switch <NUM> and the single stud fuse assembly <NUM>. The cross-sectional view shows quadrant 406d, which includes the single fuse assembly <NUM>, and quadrant 406c, which is adjacent to quadrant 406d. The landing pad <NUM> is shown, with the stud base receptacle <NUM> surrounding the stud base <NUM> of the stud <NUM>. The stud <NUM> features the threaded portion <NUM>, which is disposed above the single stud fuse <NUM>, the unthreaded portion <NUM>, which is disposed inside the shaft receptacle <NUM> of the single stud fuse <NUM>, the insulated portion, which is disposed between the stud base receptacle <NUM> and the bottom of the single stud fuse <NUM>, the optional integrated washer <NUM>, and the stud base <NUM>, both the insulated portion 318a and the steel portion 318b visible.

The shaft <NUM> of the landing pad <NUM> fits into the plastic housing <NUM> of quadrant 406d of the disconnect switch <NUM>, much like the stud 402c fits into the plastic housing <NUM> of quadrant 406c. The shaft <NUM> is electrically connected to a first busbar portion 502a, which is connected to a second busbar portion 502b (collectively, "busbar <NUM>"), and the second busbar portion 502b is electrically connected to the stud 402c. Thus, by way of the busbar <NUM>, the single stud fuse assembly <NUM> in quadrant 406d is electrically connected to the stud 402c in quadrant 406c.

Thus, current may flow from a terminal (not shown) connected to the stud 402c, through the busbar <NUM>, into the single stud fuse assembly <NUM>, and out the power cable lug <NUM>, and vice-versa. As explained above, the insulation of the stud <NUM> ensures that electrical current coming passing through the single stud fuse assembly <NUM> does not travel through the stud <NUM>, but instead passes from the metal terminal of the landing pad <NUM> through the fuse <NUM>, and vice-versa.

The power cable lug <NUM> is shown connected to the single stud fuse assembly <NUM> in quadrant 406d and may be a terminal for a battery, as one example. When a second terminal is connected to the stud 402c, the disconnect switch <NUM> becomes part of a closed circuit including the battery. A lever assembly <NUM> disposed between the first busbar portion 502a and the second busbar portion 502b is connected to the lever <NUM>, which is not shown in <FIG> but is shown in <FIG> and <FIG>). Accordingly, the lever <NUM> is able to disconnect the first busbar portion 502a from the second busbar portion 502b. This operation would open the circuit including the battery, thus disabling the battery from being operable.

In an exemplary embodiment, the shaft <NUM> and landing pad <NUM> of the single stud fuse assembly <NUM> are orbital riveted to the plastic housing <NUM>. The orbital riveting operation locks the shaft <NUM> in place in the receiving hole or pocket of the plastic housing <NUM>, so that the shaft cannot be removed or backed out. Once the shaft <NUM> of the landing pad <NUM> is orbital riveted into the plastic housing <NUM>, the shaft <NUM> appears wider and shorter, as shown in <FIG>. The riveting operation ensures an electrical connection of the shaft <NUM> to the busbar <NUM>, which is a moveable component. The stud 402c also makes an electrical connection to the busbar <NUM> during its installation. The orbital riveting of the shaft <NUM> to the busbar <NUM> allows much better sealing of the connection compared to a steel stud going through the busbar, in exemplary embodiments. Thus, once installed in the disconnect switch <NUM>, the landing pad <NUM> will not be removable from the quadrant 406d.

In an exemplary embodiment, the stud base <NUM> of the electrically isolated stud <NUM> is inserted into the stud base receptacle <NUM> before the landing pad <NUM> is orbital riveted into the plastic housing <NUM> of the disconnect switch <NUM>. This prevents the stud <NUM> from being removable from the landing pad <NUM>. In another embodiment, the landing pad <NUM> is orbital riveted into the plastic housing <NUM> before the stud base <NUM> of the electrically isolated stud <NUM> is inserted into the stud base receptacle <NUM>. Because their physical design ensures a secure mating, no additional securing mechanism of the stud base <NUM> to the stud base receptacle <NUM> is needed. Nevertheless, the stud base <NUM> may optionally be orbital riveted, locked with a secondary lock, inserted using a bottleneck, or otherwise further secured. Once installed, the stud <NUM> is strongly connected with the landing pad <NUM> and secured with the nut <NUM>, ensuring that the stud <NUM> does not get lost during goods handling, such as transport, in assembly line, etc..

In an exemplary embodiment, the disconnect switch <NUM> can be mounted in a vehicle near a wall, with the quadrant 406c being positioned against the wall such that the stud base <NUM> cannot be moved horizontally out of the stud base receptacle <NUM>. An "against a wall" positioning of the disconnect switch <NUM> would not prevent the single stud fuse <NUM> from being removed, as fuse removal would still be available to the customer should the fusible element be broken.

In <FIG>, the stud <NUM> appears to be thinner than the stud 402c. In an exemplary embodiment, the device assembly <NUM> can be used with different sizes of studs. The studs may be M6, M8, or M10, for example, and the configuration illustrated in <FIG>, <FIG>, and <FIG> would not otherwise change. In an exemplary embodiment, the shaft <NUM> of the landing pad <NUM> is sized to fit into the receiving hole or pocket of the plastic housing <NUM>. The size of the shaft <NUM>, however, does not impact the size of the threaded portion <NUM> of the stud shaft <NUM> of the stud <NUM>. Thus, with the single stud fuse assembly <NUM>, the shaft <NUM> of the stud <NUM> could change, while the shaft <NUM> of the landing pad <NUM> would not change, and would be sized to fit into the plastic housing <NUM> of the disconnect switch <NUM>. This allows end of line adjustments to customer variations.

Further, in an exemplary embodiment, any location on the disconnect switch <NUM> can be assembled with any one of the stud sizes. Thus, the single stud fuse assembly <NUM> can occupy any of the four quadrants <NUM> of the disconnect switch <NUM>. Further, the single stud fuse assembly <NUM> can be placed in two of the four quadrants <NUM>, such as when the disconnect switch <NUM> is connected to two different circuits, thus providing fuse protection for both circuits.

<FIG> is a bottom view of the device assembly <NUM>, according to exemplary embodiments. The device assembly <NUM> features the disconnect switch <NUM> with the bottom portion including the lever not being included, as in <FIG>. The four quadrants <NUM> are visible, with studs <NUM> occupying three of the quadrants, and the single stud fuse assembly <NUM> occupying the quadrant 406d. The shaft <NUM> is visible in the fourth quadrant, with the power cable lug <NUM> being partially visible.

<FIG> are perspective cutaway illustrations of a single stud fuse <NUM> suitable for the single stud fuse assembly <NUM> and the device assembly <NUM> featuring both the single stud fuse assembly <NUM> and the disconnect switch <NUM>, according to exemplary embodiments. In an exemplary embodiment, the single stud fuse <NUM> features a rectangular cubic housing. A cover portion <NUM>, when removed, reveals a fusing element <NUM> disposed to one side of the fuse <NUM>. The fusing element <NUM> is the intentional weak link of the single stud fuse <NUM> that is designed to break upon the occurrence of an overload event, such as overcurrent, overvoltage, or both. A shaft receptacle <NUM> is for receiving an insulated shaft, such as the shaft <NUM> of the insulated stud <NUM> described above. In an exemplary embodiment, the fusing element <NUM> is disposed to one side of the rectangular cubic housing while the shaft receptacle <NUM> is more centrally located within the housing. Other configurations are possible, though, in exemplary embodiments, the shaft receptacle <NUM> is both physically and electrically isolated from the fusing element <NUM>.

<FIG> is another cross-sectional view of the device assembly <NUM>, according to exemplary embodiments. In contrast to <FIG> and <FIG>, the disconnect switch <NUM> includes the bottom portion with the lever. Further, the view of <FIG> is a mirror image of that seen in <FIG>, with the quadrant 406c being on the left side and the quadrant 406d being on the right side. The stud 402c is in quadrant 406c, with the hex nut 404c holding it in place in the plastic housing <NUM> of the disconnect switch <NUM>. The stud 402c is electrically connected to the left portion 502b of the busbar, with the right portion 502a of the busbar being electrically connected to the shaft <NUM> of the landing pad <NUM>. The lever assembly <NUM>, which is connected to the lever <NUM>, enables or disables connection between the two portions 502a and 502b of the busbar.

Arrows in <FIG> shows an electrical path for current traveling through the single fuse assembly <NUM>, according to exemplary embodiments, and assumes the lever <NUM> is positioned so that the busbar <NUM> is electrically connected to the stud 402c and the landing pad stud <NUM>, as the busbar acts as a mobile bridge, moving up or down depending on the lever position. Further, a current path in one direction is shown, from the stud 402c in quadrant 406c to the power cable lug <NUM> in quadrant 406d. However, the current may travel in the opposite direction, that is, from the power cable lug <NUM> in quadrant 406d to the stud 402c in quadrant 406c. Current travels from the stud 402c, through the left portion 502b of the busbar to the right portion 502a of the busbar. Current then travels up the shaft <NUM> of the landing pad <NUM> and around the stud base receptacle <NUM>. Recall that the landing pad <NUM>, a metal terminal, is made of an electrically conductive material, such as copper or copper allow. Further, the stud <NUM> is electrically insulated at the stud base <NUM>, the optional integrated washer <NUM> (not shown), and along the above-described portions of the shaft <NUM>. Thus, current does not enter the stud base <NUM> as it travels around the stud base receptacle <NUM>. Instead, current travels to the single stud fuse <NUM> and travels around one side of the fuse. From the view of <FIG>, the current is traveling along a right side. <FIG>, above, show that the fusing element is located on one side of the fuse housing. Thus, from the view of <FIG>, the fusing element is disposed on the right side of the single stud fuse <NUM>. The current then travels to the power cable lug <NUM>, and onto the circuit, such as a battery, to which the disconnect switch <NUM> is connected.

<FIG> and <FIG> are perspective drawings of a power distribution module (PDM) assembly <NUM> featuring a PDM <NUM> and the single stud fuse assembly <NUM> of <FIG>, according to exemplary embodiments. In <FIG>, only the stud <NUM> and landing pad <NUM> are shown; in <FIG>, the entire single stud fuse assembly <NUM> is shown, along with the power cable lug <NUM>. Three stud locations 902a, 902b, and 902c are shown (collectively, "stud positions <NUM>"), with the third stud position 902c being replaced with the stud <NUM> and landing pad <NUM> (<FIG>) or with the entire single stud fuse assembly <NUM> (<FIG>). It is possible for all three stud locations 902a, 902b, and 902c to be replaced with single stud fuse assemblies <NUM>.

As with the disconnect switch <NUM>, the PDM <NUM> includes circuitry within the housing to establish a connection between the stud positions <NUM>. For example, a first busbar may be disposed between stud position 902a and 902b, thus enabling an electrical connection to be made between the studs disposed on the stud positions. A second busbar may be disposed between stud position 902a and 902c, for enabling an electrical connection between studs disposed thereon. Similarly, a third busbar may be disposed between stud position 902b and 902c. Thus, once terminals are connected between any two of the studs occupying the stud positions <NUM>, a closed circuit may be established. With the single stud fuse assembly <NUM> being disposed on one, two, or all three of the stud positions <NUM>, the single stud fuse <NUM> is able to protect the device connected to the terminals.

As with the disconnect switch <NUM> (<FIG>, <FIG>, <FIG>, <FIG>, and <FIG>), the assembly <NUM> including the PDM <NUM> and the single stud fuse assembly <NUM> can be used with different sizes of studs, such as M6, M8, or M10. In an exemplary embodiment, any location on the device can be assembled with any one of the stud sizes. The shaft <NUM> of the stud <NUM> of the single stud fuse assembly <NUM> can change while the shaft <NUM> of the landing pad <NUM> would not change, and would be sized to fit the plastic housing <NUM> of the PDM <NUM>. This allows end of line adjustments to customer variations. Further, in an exemplary embodiment, more than one stud location, 902a, 902b, or 902c, can be assembled with any of the stud sizes. Thus, the single stud fuse assembly <NUM> can occupy any of the stud locations <NUM> of the PDM <NUM>. Further, the single stud fuse assembly <NUM> can be placed in more than one stud position <NUM>, such as when the PDM <NUM> is connected to two different circuits, thus providing fuse protection for both circuits. Finally, customization of the PDM <NUM> is possible without any retooling of the stud.

<FIG> is a flow diagram illustrating a method <NUM> of assembling a single stud fuse assembly, such as the single stud fuse assembly <NUM>, in an electronc device, such as the disconnect switch <NUM> or the PDM <NUM> described and illustrated above. For clarity, the reference numbers of the single stud fuse assembly <NUM> (<FIG>) are given in parentheses, though the method steps may apply to other configurations of single stud fuse assemblies. The shaft (<NUM>) of the landing pad (<NUM>) is inserted into a hole of the housing (<NUM>) of the electrical device (block <NUM>). The electrical device may be made of plastic material similar to that of the disconnect switch <NUM> and PDM <NUM> described herein, and a cylindrical hole in the plastic housing (<NUM>/<NUM>) will be suitable for receipt of the shaft (<NUM>) of the single stud fuse assembly <NUM>. The bottom rectangular-cube-like portion of the insulated stud (<NUM>), known as the stud base (<NUM>), which is insulated, is inserted into the stud base receptacle (<NUM>) of the metal terminal (<NUM>), known as the landing pad, which is sized to receive the insulated base (<NUM>). The shaft (<NUM>) of the steel stud (<NUM>), some of which is also insulated, fits flush against an inside edge of the inset portion (<NUM>) of a top surface of the stud base receptacle (<NUM>) (block <NUM>).

The shaft (<NUM>) of the electrically isolated stud <NUM> is next inserted through the receiving aperture or shaft receptacle (<NUM>) of the single stud fuse (<NUM>) until the fuse is disposed atop the stud base receptacle (<NUM>) of the landing pad (<NUM>) (block <NUM>). At this stage, the insulated portion (<NUM>) of the shaft (<NUM>) is partially inserted into the shaft receptacle (<NUM>) of the single stud fuse (<NUM>). The cable lug aperture aperture (<NUM>) of the power cable lug (<NUM>) is positioned over the shaft (<NUM>) of the stud (<NUM>) until the power cable lug (<NUM>) is flush against the top surface of the single stud fuse (<NUM>) (block <NUM>). The optional washer (<NUM>), if present, and nut (<NUM>) are disposed over the shaft (<NUM>) of the stud (<NUM>), and secured tightly thereon (block <NUM>). Alternatively, the shaft (<NUM>) of the stud (<NUM>) is secured by a nut having an integrated washer, such as a flange nut, a trilobate nut, or other type of nut that can be used without a washer. The electrical device, once enabled, such as by the lever in the disconnect switch described above, is now part of the circuit at the end of the terminals. Further, the circuit is now protected by the single stud fuse of the single stud fuse assembly (block <NUM>).

Thus, as illustrated and described herein, any electrical device that is to be part of an electrical circuit in which connection is made by cables, harnesses, or other means, the electrical device having a hole to be blocked (and electrically connected) between a stud and a nut may be a good candidate for adding the single stud fuse assembly <NUM>. The disconnect switch <NUM> and the power distribution module <NUM> represent but two of myriad devices that may be suitable for the method operations described in <FIG>.

Claim 1:
An electrical device assembly (<NUM>, <NUM>) comprising:
an electrical device (<NUM>, <NUM>) comprising:
a first stud (402c) adapted to be coupled to a first terminal;
a receiving hole in a housing of the electrical device; and
a single stud fuse assembly (<NUM>) comprising:
a single stud fuse (<NUM>) comprising a shaft receptacle (<NUM>);
a landing pad (<NUM>) comprising a landing pad shaft (<NUM>) and a stud base receptacle (<NUM>), the landing
pad shaft being orbitally riveted into the receiving hole of the housing; and
an electrically isolated stud (<NUM>) comprising a stud shaft (<NUM>) and a stud base (<NUM>), wherein:
the stud base being inserted into the stud base receptacle;
the single stud fuse is disposed along the stud shaft, with the stud shaft being disposed through the shaft receptacle, the stud shaft adapted to be coupled to a second terminal.