Wire termination apparatus and method

An electrical termination and method comprising an element and a conductive member is disclosed. A wire is manually or tool-lessly securable in electrical communication with the conductive member.

BACKGROUND

1. Technical Field

The present disclosure relates to wiring devices, and in particular, to wiring devices having wire termination subassemblies.

2. Description of Related Art

Wiring devices are typically provided with device terminations for terminating electrical conductors/wires, for example, load terminations, line terminations, ground terminations, etc. Together these terminations, depending on the mechanical configuration, may be connected to electrical conductors/wires using several presently known termination techniques. One such termination is referred to as “side-wire” (sometimes referred to as “wrap-wire”) termination. To terminate a conductor/wire using a side-wire terminal, an end of the wire is initially stripped, exposing a portion of the end of the wire, and this exposed portion is then wrapped around a terminal screw. The screw is then tightened causing the head of the screw to secure the exposed wire between the head of the screw and a metallic terminal plate (e.g., a brass terminal).

Another type of wire termination is referred to as “back-wire” (also referred to as “clamp-wire”). In back-wire terminals, a screw passes through a first metallic plate and threads into a second metallic plate (referred to as a clamp) to compress a wire therebetween. The first metallic plate (or brass terminal) has a clearance opening and slides along the shaft of the screw. The second metallic plate has a threaded hole which the screw threads engage. A stripped wire is placed between the two metallic plates and the screw is tightened to compress the wire between the plates.

Yet another type of wire termination is referred to as a “push in” termination. Push-in terminations are terminals in which a small hole is available in the outer housing of a wiring device for insertion of a stripped wire therethrough. A solid-metal wire is initially stripped (e.g.—about five-eights of an inch) from the cut end. The stripped portion of the wire is inserted into the hole. A clamping mechanism, commonly in the form of a cage clamp, provides a clamping force on the wire to maintain it in contact with a terminal plate for establishing electrical contact with the wire. The clamping mechanism provides resistance against the wire being pulled out of the hole and out of contact with the terminal plate. Typically, a tool is required to release the wire; e.g., a screwdriver.

In view of the foregoing, it is desirable for wiring devices including termination mechanisms and methods of termination that provide convenient electrical terminations for various gauge conductors/wires.

SUMMARY

The present disclosure relates to an electrical distribution wiring device comprising a housing having a plurality of wire terminations. At least one of the wire terminations comprises a conductive member and a lever. The conductive member is at least partially disposed within the housing. The lever is rotationally mounted to the conductive member and is manually rotatable between at least a first position and a second position. The lever includes a rotational axis and an eccentric surface defined with respect to the axis. When the lever is in the first position, the lever allows a wire to be inserted into the wire termination. When the lever is in the second position, the lever causes the eccentric surface to secure the wire to the conductive member.

In disclosed embodiments, wherein the conductive member includes a V-like shape having two legs configured to receive the wire.

In disclosed embodiments, the conductive member includes a resilient member formed therein; the resilient member, the lever and the conductive member are configured to interact with one another to allow securement of wires of different gauges with the conductive member.

In disclosed embodiments, all exposed surfaces of the electrical distribution wiring device which can be contacted by a human finger are electrically isolated from line voltage when the lever is in its second position.

In disclosed embodiments, the lever includes an element locking structure and the housing includes a housing locking structure. The element locking structure is configured to engage the housing locking structure when the lever is moved towards its second position.

In disclosed embodiments, the conductive member comprises a first terminal, a second terminal and a conductive member breakaway portion that connects the first terminal with the second terminal. The housing includes a housing breakaway portion, which is configured to at least partially shield the conductive member breakaway portion.

In disclosed embodiments, the lever is a hand operable lever.

The present disclosure also relates to a wiring device comprising a housing, and a wire termination subassembly. The wire termination subassembly is disposed at least partially within the housing. The wire termination subassembly comprises a conductive member and an element. The element is disposed in mechanical cooperation with the conductive member and is pivotable about a first axis between a first position where a wire is insertable between the element and a portion of the conductive member, and a second position where the wire is removably secured between the element and a portion of the conductive member. The element is manually movable between the first position and the second position.

In disclosed embodiments, the conductive member comprises at least one resilient member formed therein, wherein the at least one resilient member, the element and the conductive member mechanically cooperate to allow securement of wires having different gauges.

In disclosed embodiments, the element includes an element locking structure thereon which is configured to selectively engage a housing locking structure disposed on the housing when the element is moved towards its second position.

In disclosed embodiments, the element comprises a pivot portion and the pivot portion includes a reinforcing member.

In disclosed embodiments, the element is hand operable.

The present disclosure also relates to a wire termination comprising a conductive member and a lever. The lever is rotationally mounted to the conductive member and is manually rotatable between at least a first position and a second position. The lever includes a rotational axis and an eccentric surface defined with respect to the axis. The lever in the first position allows a wire to be inserted between the lever and the conductive member, and the lever in the second position causes the eccentric surface to secure the wire to the conductive member.

The present disclosure also relates to a wire termination comprising a conductive member and an element. The element is disposed in mechanical cooperation with the conductive member and is pivotable about a first axis between a first position where a wire is insertable between the element and a portion of the conductive member, and a second position where the wire is removably secured between the element and a portion of the conductive member/The element is manually movable between the first position and the second position.

The present disclosure also relates to a method for terminating a wire. The method comprises manually moving a lever to allow a portion of a wire to be inserted between a conductive member and an eccentrically cammed surface of the lever, inserting a portion of a wire between the conductive member and the eccentrically cammed surface of the lever, and manually moving the lever to removably secure the wire between the conductive surface and the eccentrically cammed surface of the lever such that the wire is manually removable from between the conductive surface and the eccentrically cammed surface of the lever.

The present disclosure also relates to a method of manufacture for an electrical termination of a wiring device. The method includes the step of mounting a conductive member at least partially within the wiring device where the conductive member includes at least one inwardly extending resilient member, a mounting region having at least a first width, and a wire-contact portion. The method also includes the step of mounting a wire termination mechanism within the mounting region of the conductive member. The wire termination mechanism has a shaft and is pivotable about the shaft between at least a first position and a second position. The wire termination mechanism is constrained within the at least first width of the mounting region by the inwardly extending resilient member, such that manufacturing tolerances are controlled.

DETAILED DESCRIPTION

Referring initially toFIG. 1, an electrical wiring distribution device (hereinafter “wiring device”), including at least one wire termination subassembly according to an embodiment of the present disclosure, is generally designated as100. Wiring device100is in the form of an electrical receptacle, in particular, a duplex three-prong electrical receptacle for handling 15 amp current applications. However, it should be understood that the receptacle can be a two- or three-prong electrical receptacle or a receptacle other than that of a duplex receptacle. It should also be understood that the term “wiring device” is intended to include any standard electrical wiring device commonly known in the electrical industry, including but not limited to switches, ground fault circuit interrupters, dimmers, fan speed controls, occupancy sensors and the like.

With continued reference toFIG. 1, wiring device100includes a housing110having a base portion or lower portion112and a cover portion or upper portion114. Cover portion114configured and dimensioned for connection to base portion112. Additionally, wiring device100includes a conductive member120(seeFIGS. 3-5and5AA) disposed at least partially within housing110and at least one wire termination subassembly, generally referred to as numeral200(FIG. 5). Wire termination subassembly200is adapted and configured to removably secure/terminate a portion of a wire “W” to conductive member120, thus enabling electrical communication between wiring device100and wire “W” (seeFIGS. 6 and 7).

With reference toFIG. 2, base portion112of housing110of wiring device100is more clearly shown. As illustrated, base portion112includes a plurality of openings113extending therethrough. Each opening113is configured to accept a portion of a wire therethrough. Further, each opening113is substantially aligned with a portion of conductive member120, such that a wire is insertable through opening113and into electrical engagement with conductive member120(for hot & neutral).

With reference toFIG. 5, components of wire termination subassembly200are illustrated. Wire termination subassembly200includes conductive member120and an element202. In the illustrated embodiment, element202includes a hand-operable lever210, cam212(FIG. 6) and pin214. Pin214defines a first longitudinal axis “A-A.” Element202is rotatable (e.g., pivotable) about pin214. It is envisioned that first longitudinal axis “A-A” extends through the cam's axis, e.g., an off-center portion of cam212. Thus, it is envisioned that cam212is an eccentric disc-like member. It is envisioned that such a cam would be adapted and configured to apply a continually increasing amount of force against wire “W” upon movement of lever210. Moreover, it is envisioned that the initial movement of lever210would require less force than when lever210is moved to its final position. Accordingly, for such a configured cam, it would take a relatively larger amount of force to move lever210back towards its initial position. Thus, as lever210is moved towards its second position, there is a greater force acting on a wire “W” to adequately terminate and/or help maintain the wire “W” secured between cam212and conductive member120. FIG.5AA illustrates an assembly view of the wire termination subassembly200ofFIG. 5. Alternatively, as opposed to including cam212, element202may comprise a constant radius portion. In such an embodiment, it is contemplated that the cammed surface may be provided by a channel having a varying depth or radius along the channel length such that when the element is in its first position a wire may be freely inserted and when the element202is moved to it's second position, the wire is secured by an increasing force due to the varying depth or radius of the channel. It is envisioned that element202is made entirely of a non-conductive material such as, but not limited to, plastic (polyamide 6-6 or PA66), ceramic, or the like. It is also envisioned that element202can comprise both non-conductive material and conductive material. For example, it is envisioned that pin214can be made of a non-conductive material and include a bore disposed therethrough, wherein reinforcing rod can be inserted through and extending through the bore (e.g., the reinforcing rod can be made of a metal or composite material that may be at least partially conductive). It is further disclosed that all exposed surfaces of the wiring device100(i.e., surfaces accessible from the exterior that can be touched/contacted with a human finger or mechanical probe) are either made of non-conductive materials and/or are electrically isolated. See alsoFIGS. 12-14.

With reference toFIGS. 12-14, in at least one embodiment, the lever210may include a lever body with a channel and a pocket at a distal end, a lever core, and a pin. The pocket is disposed to receive a tab on the lever core. The lever core may be then inserted/rotated into the channel in the lever body and into alignment with the lever body. Then the pin can be inserted through the lever body and the lever core, securing the assembly together without the need for additional fasteners or parts. The pin may be secured to the lever body and/or lever core via a press, interference, or any other suitable fit.

With continued reference toFIG. 5, conductive member120includes a V-like portion126having two legs126a,126b.It is envisioned that each leg126a,126bis configured to simultaneously contact a wire “W.” In addition, one or both of legs126a,126bcould be adapted and configured to have a textured surface for enhanced termination/gripping of wire W; e.g., serrations, teeth, or the like.FIGS. 6 and 7illustrate the wire “W” in contact with a single leg126a,while the other leg126bis not explicitly shown for clarity. Alternatively, conductive member120may include a flat portion, as opposed to a V-like portion126, to contact the wire. In at least one embodiment, if conductive member120includes a V-like portion126, the profile of cam212may be flat. Alternatively, if conductive member120includes a flat portion, the profile of cam212may be flat in the center with the outer edges being extended to aid in centering the wire in the termination.

Referring nowFIG. 5A, there is shown an alternate embodiment to that shown inFIG. 5. The embodiment inFIG. 5Ais similar to the embodiment shown inFIG. 5with some differences. On one side each of lever (not shown inFIG. 5A) is located a flexible wing141. Flexible wing141is provided such that a larger size wire, # 12 AWG for example, can be more easily accommodated. Flexible wing141makes it easier for the contact to flex an extra amount when using a larger size wire as opposed to a smaller wire size, # 14 AWG for example. For example, the extra amount of flexing may be in the order of about 0.020 inches.

In addition, a window or cutout region127is provided on the center of contact opposite the lever as opposed to a scoreline. The window127provides for two sharp corners or edges that engage the wire to be terminated instead of engaging the wire with a scoreline. The provision of windows127may be provided as opposed to the scoreline in order to simplify the manufacturing process.

As shown in the embodiment depicted inFIG. 5, element202is pivotally mounted within a portion of conductive member120. More particularly, pin214of element202is configured to engage a recess, or mounting region122of conductive member120. As can be appreciated, the interaction between pin214and recess122facilitates the pivotal relationship between element202and conductive member120. It is envisioned that recess122has a constant width (not shown) or includes a rounded portion (as shown inFIG. 5, for example). The rounded portion, in conjunction with the resilient member142, provide tolerances to accommodate various gauge wires (e.g., 12- and 14-gauge).

With reference toFIG. 9, dimensions “A,” “B” and “C” are shown and help illustrate how having element202being pivotable about a portion of conductive member120helps minimize the manufacturing tolerances. That is, by assembling elements202into conductive member120, the tolerance chain is reduced to only two dimensions, i.e., dimensions “A” and “B.” That is, the critical dimension “C” is solely dependent on dimensions “A” and “B.” Moreover, lower portion112and upper portion114of housing110have no effect on the system tolerance. In this embodiment, as opposed to other embodiments, the tolerance chain is relatively shorter, part complexity is lower, and assembly is relatively less complicated. Such an embodiment may be less expensive to produce and yield less waste during production.

Referring back toFIG. 5, conductive member120is shown in one embodiment including a two pairs of resilient members140a,140b.Resilient members140a,140bare configured for biasing pin214of element202. In the illustrated embodiment, each terminal (i.e., first terminal120aand second terminal120b) includes a respective pair of resilient members140a,140band each resilient member140is formed from a portion of conductive member120and protrudes inwardly from an outer surface124of conductive member120. At least a portion of resilient member140, e.g., an end142of resilient member140is arranged and configured to contact pin214of element202and bias a wire W inserted into the V-like portion126against the surfaces126a,126b.In this embodiment, at least one pair of resilient member140a,140bfor each terminal120a,120bis configured to be able to flex towards surface124in response to a predetermined amount of force acting there against. Moreover, the interaction between element202, V-like portion126of conductive member120, and resilient member140facilitates securement of wires of different gauges (i.e.—sizes) with conductive member120. More particularly, upon insertion of a wire having a sufficiently large gauge (i.e., one that would cause at least one of the resilient member pairs140a,140bto deform or flex), at least one of the resilient member pairs140a,140bwould flex towards outer surface124to accommodate the wire, which would allow pin214of element202to be urged/biased towards outer surface124.

With reference toFIGS. 6 and 7, element202is movable between a first position (FIG. 6), where a wire “W” in insertable between cam212and a portion of conductive member120, and a second position (FIG. 7), wherein the wire “W” is secured between cam212and a portion of conductive member120. Moreover, a user can move element202from its first position, to its second position without the use of a tool; e.g. a user could actuate element202by hand alone, i.e., without requiring a screwdriver, etc. In an alternative embodiment, the user could move element202from its first position, to its second position with the use of, or with the help of, a tool. Thus, in certain embodiments, the wire “W” may be tool-lessly securable and removably secured in electrical communication with conductive member120That is, element202is movable in the general direction of arrow “A-A” inFIG. 1. As shown, the portion of wiring device between cam212and conductive member120, i.e., a wire-accepting slot or region125, defines a second longitudinal axis “B-B,” which is substantially perpendicular to first longitudinal axis “A-A” (seeFIG. 5). Although in this embodiment axes “A-A” and “B-B” are perpendicular to each other, the axes may be disposed at any suitable angle with respect to each other. It is envisioned that wire-accepting slot or channel125includes a constant width or a varying width.

When used herein, the term “tool-lessly” refers to a wire termination mechanism that may be actuated without the need or use of a tool or implement, e.g., hand-operable. This may include the ability to operate/actuate the wire termination mechanism both to secure a wire and to release a wire. However, it should be clear that the actuators of the wire termination mechanisms which are adapted and configured to be manually operable without the need or use of a tool or implement, may still be conceivably operated with a suitably selected tool or implement; i.e., tool-lessly operable wire termination mechanisms do not necessarily exclude manual operation by means of a tool or implement.

With continued reference toFIGS. 6 and 7, element202may be temporarily locked into place (e.g., in its second position) when a portion of element202(e.g., an element locking structure216) engages a housing locking structure250disposed on a portion of wiring device100. It is further envisioned that engagement between element locking structure216and housing locking structure250provides the user with user-perceptible feedback (e.g., tactile or audible) signifying that element202is locked in place. Element and housing locking structures216,250are envisioned as being complementary mechanical locking mechanisms which cooperate to selectively lock element202into its second position; e.g., an over snap latch, a ratcheting finger, or the like.

Additional contemplated features of element202will now be described with reference toFIGS. 6 and 7. In the illustrated embodiments, element202includes a finger260thereon. It is envisioned that when element202is in its first position (FIG. 6), finger260functions as a wire stop. That is, finger260may guide a user to position a wire at a desirable depth adjacent conductive member120. When element202is in its second position (FIG. 7), finger260may help limit external access to within housing110. That is, finger260may help prevent a user from unintentionally contacting conductive member120. Further, it is envisioned that element202may include a channel264disposed along at least a portion of a wire-contacting surface thereof. It is further envisioned that the radius of channel264may be non-constant. That is, the radius of channel264may increase or decrease towards the location where finger260is illustrated. Channel264may help a user guide a wire between element202and conductive member120.

Alternatively, in at least one embodiment, finger260may be omitted and instead the housing, or other suitable element, may be configured to limit or stop the lever near it's first position. If finger260is omitted, the termination may be configured such that the wire-accepting slot125is uninterrupted by the lever or a portion thereof at any point of the range of motion of the lever between it's first and second positions.

Referring back toFIGS. 1 and 3, it is envisioned that a portion of housing110includes a break-away portion1111(FIG. 1). Break-away portion111is configured to conceal a connecting portion121or conductive break-away portion (FIG. 4) of conductive member120. Connecting portion121is the bridge between first terminal120aand second terminal120bof conductive member120(FIG. 5). To access and sever the connecting portion121(e.g., to electrically separate the two terminals), a user can sever break-away portion111from the other portions of housing110by use of a mechanical force or via a separate tool. Additionally, housing110may include a rib130(and/or rib132shown inFIG. 8) disposed thereon, which is positioned such that rib130(and/or rib132) is substantially aligned between, or adjacent to the two terminals of conductive member120. It is envisioned that rib130(and/or rib132) helps physically separate and maintain the position the two terminals after connecting portion121has been severed. It is further envisioned that rib130(and/or rib132) helps key (e.g. register/align) the cover portion114with respect to base portion112to help ensure proper assembly.

The present disclosure also relates to a wire termination subassembly200for use with a wiring device100. The wire termination subassembly200includes a conductive member120, and an element202disposed in mechanical cooperation with the conductive member120. The element202is pivotable about a portion of the conductive member120between a first position where a wire is insertable between the element202and a portion of the conductive member120, and a second position where the wire is secured between the element202and a portion of the conductive member120. In disclosed embodiments, the element202is tool-lessly movable between its first position and its second position.

As can be appreciated, wire termination subassembly200facilitates the insertion and removal of a wire “W” with respect to wiring device100. To secure a wire “W” into wire termination subassembly200of wiring device100, a user (a licensed electrician, homeowner, or the like) can position lever210in its first, open position, insert a portion of wire “W” (e.g., a bare stripped portion of wire W) between cam212and conductive member120, and move lever210towards its second, closed position, such that a portion of cam212moves towards the wire, thus firmly securing wire “W” between cam212and conductive member120. To remove wire “W” from wire termination subassembly200of wiring device100, the user moves lever210from its second, closed position towards its first, open position. This movement of lever210causes cam212to release wire “W,” such that wire “W” is free to longitudinally translate, thus allowing the user to remove the wire “W” from wiring device100.

The illustrated embodiments of wiring device100show five separate elements202. It is envisioned that each terminal120a,120bincludes one element202associated therewith Additionally, while not explicitly shown, it is envisioned that wire termination subassembly200including element202can be used in combination with other types of wire termination subassemblies. Additionally,FIG. 10illustrates an embodiment of a ground terminal300, andFIG. 11illustrates wire termination subassembly200and ground terminal300.

The present disclosure also relates to a method of wiring an electrical device100. The method includes the steps of providing an electrical device100including a conductive member120and an element202, inserting a portion of a wire “W” such that a portion of the wire “W” contacts the conductive member120, and tool-lessly moving the element202with respect to the conductive member120to secure a portion of the wire “W” in contact with the conductive member120.

In various embodiments, the method may also include the following steps:

tool-lessly moving the element202with respect to the conductive member120to release the portion of the wire “W” from contact with the conductive member120; and

tool-lessly removing the wire from the electrical device.

While several embodiments of the disclosure have been shown in the drawings and/or discussed herein, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments.