The present disclosure relates generally to connection terminals for electrical wiring devices and more particularly to screwless wire terminals for use in receptacles, plug assemblies, plug connectors, switches, male inlet connectors, female inlet connectors, pin-in-sleeve connectors, motor control switches and other electrical wiring devices.
Present electrical wire terminations in many electrical wiring devices are either direct pressure type terminations or screw and clamp type terminations. In direct pressure type terminations, a terminal screw is tightened directly against an electrical wire to press the wire against a fixed plate. In screw and clamp type terminations, a wire is inserted between a fixed plate and a movable plate, and a terminal screw is tightened so that the wire is clamped between the plates. With direct pressure type terminations, stranded or solid wires, if incorrectly installed can be cut or nicked. Cut or nicked wires can result in poor electrical connections increasing the resistance in the connections which can cause overheating. In addition, with stranded wires, both direct pressure type terminations and screw and clamp type terminations may be susceptible to strand relaxation. Strand relaxation is a result of copper wire heating and cooling under the stress of the termination, either direct pressure type or screw and clamp type causing the electrical connection between the stranded wire and the termination to loosen increasing the resistance in the connections which can cause overheating. To alleviate strand relaxation concerns, installers typically re-torque terminal screws after some duration of time after original installation increasing costs to consumers.
The present disclosure provides embodiments of electrical wiring devices that incorporate the wire terminals and activating members according to the present disclosure. The wire terminals and activating members according to the present disclosure are described with the electrical wiring device being a twist lock electrical receptacle. However, the present disclosure contemplates that the wire terminals and activating members may be used with any electrical wiring devices, including other types of receptacles, plug assemblies, plug connectors, single or multi-pole electrical switches, combination switches and receptacles, motor control switches, male inlet connectors, female inlet connectors, pin-in-sleeve connectors, and other electrical wiring devices. Other types of receptacles include, but are not limited to, duplex receptacles, single receptacles, GFCI receptacles and AFCI receptacles. Other types of switches include, but are not limited to, three-way switches and four-way switches. The electrical wiring devices contemplated include, but are not limited to, single phase or single pole electrical wiring devices or multi-phase or multi-pole electrical wiring devices. Non-limiting examples of such devices are provided in commonly owned U.S. Pat. No. 10,461,444 and U.S. Provisional Patent Application No. 63/425,891 the contents of each are incorporated herein in their entirety by reference.
In an exemplary embodiment described herein, a twist lock blade-type electrical receptacle is provided that includes a housing and a plurality of contact assemblies, where each contact assembly includes a wire terminal and a corresponding activating member according to the present disclosure. The housing has a main body with a plurality of cavities, a front cover and a rear cover. The front cover is removably secured to a first side of the main body and includes a plurality of blade receiving slots or openings. The rear cover is removably secured to a second side of the main body and includes a plurality of wire receiving openings and a plurality of plunger openings.
In one exemplary embodiment, one of the plurality of contact assemblies is positioned at least partially within one of the plurality of cavities and is accessible from one of the plurality of wire receiving openings, from one of the plurality of plunger openings in the rear cover and is accessible from one of the plurality of blade receiving slots in the front cover. Each of the plurality of the contact assemblies includes a contact member and a wire terminal. In an exemplary embodiment, a removable activating member is provided and is configured to selectively interact with each of the plurality of contact assemblies to secure, clamp, connect and/or couple one or more wires to the contact assembly. The removable activating member may also be referred to herein as the “activating member” or “plunger” in the singular and as the “activating members” or “plungers” in the plural. In an exemplary embodiment, the contact member has a contact body and at least two contact fingers extending from the contact body. The at least two contact fingers are aligned with one of the plurality of blade receiving slots in the front cover. The wire terminal forms an electrically conductive path with the contact member. In one exemplary embodiment, the wire terminal includes a clamp brace and a force applying member secured to the clamp brace. In another exemplary embodiment, the wire terminal includes a clamp brace, force applying member and a contact arm. The contact arm is secured to the contact body and the clamp brace, and the force applying member is secured to the clamp brace. In both exemplary embodiments, the force applying member may be secured to the clamp brace by, for example, mechanically fitting, e.g., clipping, the force applying member to the clamp brace, or by soldering, brazing or welding the force applying member to the clamp brace. The force applying member is movable relative to the clamp brace between a closed position where a wire can be clamped between the force applying member and the clamp brace and an open position where a wire can be inserted through one of the plurality of wire receiving openings in the rear cover and between the force applying member or mechanical energy device and the clamp brace. In the exemplary embodiments described herein, the force applying member may be a clamping member that clamps a wire to the wire terminal.
The activating member is releasably attached to the housing of the electrical wiring device and is configured to be inserted into and fit within each of the plurality of plunger openings in the rear cover. When the activating member is inserted into an activating member opening, the activating member interacts with the force applying member or mechanical energy device such that movement of the activating member in a first direction relative to the clamp brace causes the activating member to apply a force or mechanical energy, e.g., a mechanical load, to the force applying member or mechanical energy device moving the force applying member or mechanical energy device from a closed position to an open position, and movement of the activating member in a second direction relative to the clamp brace removes the force or mechanical energy from the force applying member or mechanical energy device so that to the force applying member or mechanical energy device automatically returns to the closed position.
In an exemplary embodiment, the electrical wiring device includes a housing and at least one contact assembly. The housing has at least one cavity within an interior of the housing, at least one wire receiving opening and at least one activating member opening. The at least one contact assembly is positioned at least partially in the at least one cavity such that the at least one contact assembly is accessible from the at least one wire receiving opening and the at least one activating member opening. The at least one contact assembly includes a wire terminal and an activating member. The wire terminal includes a clamp brace and a force applying member secured to the clamp brace. The force applying member is movable between a first position where a wire can be secured between the force applying member and the clamp brace, and a second position where a wire can be inserted through the at least one wire receiving opening and between the force applying member and the clamp brace. The activating member can be inserted into and removed from the at least one activating member opening. When the activating member is inserted into the at least one activating member opening and into the at least one cavity, a distal end of the activating member is operatively associated with the force applying member such that further movement of the activating member into the at least one cavity causes the activating member to apply a force or mechanical energy to the force applying member causing the force applying member to move from the first position to the second position. When the activating member is removed at least from the at least one cavity, the force or mechanical energy is removed from the force applying member so that the force applying member can move, e.g., automatically move, from the second position to the first position. In an exemplary embodiment, a mounting clip is secured to an exterior of the housing, and the activating member is adapted to be releasably attached to the mounting clip when not in use.
In another exemplary embodiment, the electrical wiring device includes a housing and at least one contact assembly. The housing has an interior and an exterior, a plurality of cavities within the interior of the housing, a plurality of wire receiving openings and a plurality of activating member openings. In this configuration, one of the plurality of wire receiving openings extends from one of the plurality of cavities to the exterior of the housing, and one of the plurality of activating member openings extends from the one of the plurality of cavities to the exterior of the housing. The plurality of contact assemblies are positioned in the plurality of cavities, such that one of the plurality of contact assemblies is positioned at least partially in one of the plurality of cavities so that the one of the plurality of contact assemblies is accessible from a respective one of the plurality of wire receiving openings and a respective one of the plurality of activating member openings. Each of the plurality of the contact assemblies includes a wire terminal and a removable activating member. The wire terminal includes a clamp brace and a force applying member secured to the clamp brace. The force applying member is movable relative to the clamp brace between a first position where a wire can be secured between the force applying member and the clamp brace, and a second position where a wire can be inserted through the one of the plurality of wire receiving openings and between the force applying member and the clamp brace. The removable activating member has a first face, a second face opposite the first face, a distal end at least partially positionable in the one of the plurality of cavities, and a proximal end adapted to extend at least partially through the one of the plurality of activating member openings. The first face is at least partially operatively associated with the force applying member, such that movement of the activating member in a first direction causes the first face of the activating member to apply a force or mechanical energy to the force applying member causing the force applying member to move from the first position to the second position, and movement of the activating member in a second direction removes the force or mechanical energy from the force applying member so that the force applying member can move, e.g., automatically move, from the second position to the first position. In an exemplary embodiment, a mounting clip is secured to an exterior of the housing, and the activating member is adapted to be releasably attached to the mounting clip when not in use.
In another exemplary embodiment, the electrical wiring device includes a housing and at least one contact assembly. The housing has at least one cavity within an interior of the housing, at least one wire receiving opening and at least one activating member opening. The at least one contact assembly is positioned at least partially in the at least one cavity such that the at least one contact assembly is accessible from the at least one wire receiving opening and the at least one activating member opening. The at least one contact assembly includes a wire terminal and a removable activating member. The wire terminal has a clamp brace and a force applying member secured to the clamp brace. The force applying member is movable between a first position where a wire can be secured between the force applying member and the clamp brace, and a second position where a wire can be inserted through the at least one wire receiving opening and between the force applying member and the clamp brace. The removable activating member is positionable within the at least one activating member opening, such that when the activating member is positioned within the at least one activating member opening, a distal end of the activating member is at least partially positioned in the at least one cavity and a proximal end of the activating member extends at least partially through the at least one activating member opening. When the activating member is positioned within the at least one activating member opening, the distal end of the activating member is operatively associated with the force applying member, wherein movement of the activating member in a first direction causes the activating member to apply a force or mechanical energy to the force applying member causing the force applying member to move from the first position to the second position, and wherein movement of the activating member in a second direction removes the force or mechanical energy from the force applying member so that the force applying member automatically moves from the second position to the first position.
In another exemplary embodiment, the electrical wiring device includes a housing, a wire terminal and an activating member. The housing includes at least one cavity within an interior of the housing, at least one wire receiving opening, and at least one activating member opening. The wire terminal is positioned within the at least one cavity and has a clamp brace and a force applying member. The force applying member is movable between a closed position where a wire can be secured between the force applying member and the clamp brace, and an open position where a wire can be inserted through the at least one wire receiving opening and between the force applying member and the clamp brace. The activating member can be inserted into and removed from the at least one activating member opening. When the activating member is inserted into the at least one activating member opening and into the at least one cavity, a distal end of the activating member is operatively associated with the force applying member such that further movement of the activating member into the at least one cavity causes the activating member to apply a force or mechanical energy to the force applying member causing the force applying member to move from the closed position to the open position. When the activating member is removed at least from the cavity, the force or mechanical energy is removed from the force applying member so that the force applying member can move, e.g., automatically move, from the open position to the closed position.
In the one or all of the embodiments described herein, the activating member can remain in the first position or the second position until manually moved. In some embodiments, the movement of the activating member in the second direction may be opposite the movement of the activating member in the first direction. In other embodiments, the movement of the activating member in the first direction and the second direction may be parallel to the clamp brace. In other embodiments, the movement of the activating member in the first direction and the second direction is linear. In other embodiments, the movement of the activating member in the first and second directions may be relative to the force applying member or to the clamp brace. In still other embodiments, the movement of the activating member in the first direction may be outward relative to the housing and the movement of the activating member in the second direction may be inward relative to the housing. In still other embodiments, the movement of the activating member in the first direction may be inward relative to the housing and the movement of the activating member in the second direction may be outward relative to the housing. In some embodiments, the activating member includes a first face configured to contact at least a portion of the force applying member and a second face having a camming surface configured to contact at least a portion of the one of the plurality of camming members.
A more complete appreciation of the present disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
Exemplary embodiments of electrical wiring devices that incorporate the screwless or clamp wire terminal of the present disclosure are shown and described. Non-limiting examples of the electrical wiring devices contemplated by the present disclosure include, single and duplex blade-type electrical receptacles, blade-type locking electrical receptacles, single or multi-pole electrical switches, combination switches and blade-type receptacles, blade-type plugs for electrical cords, blade-type connectors for electrical cords, male inlet connectors, female inlet connectors and pin-in-sleeve type connectors, motor control switches and other multi-phase or multi-pole electrical wiring devices. Blade-type electrical wiring devices as described herein are; a) male blade-type electrical wiring devices with a plurality of non-circular, e.g., substantially flat or arcuate, power contact blades (hot and/or neutral contact blades) that can mate with corresponding finger contacts within a female blade-type electrical wiring device, or b) female blade-type electrical wiring devices with a plurality of non-circular, e.g., substantially flat or arcuate, power contact blade apertures (hot and/or neutral contact blade apertures) that provide access to contact fingers within the female electrical wiring devices that can mate with corresponding non-circular power contact blades of male blade-type electrical wiring devices. Examples of blade-type electrical wiring devices are described in the National Electrical Manufacture Association (NEMA) standard WD6, which is publicly available and incorporated herein in its entirety by reference. In one exemplary embodiment, a blade-type electrical wiring device includes a housing and a plurality of female contact assemblies within the housing that are accessible from an exterior of the housing.
In some embodiments, the housing has a front cover and a main body. In other embodiments, the housing has a front cover, a main body and a rear cover. In each embodiment of an electrical wiring device, each contact assembly has a contact member and a wire terminal. A removable activating member is provided and is configured to selectively interact with each of the plurality of contact assemblies to secure, clamp, connect and/or couple one or more wires to the contact assembly. The contact member is used to form a portion of a conductive electrical path. The wire terminal is used to terminate an electrical conductor inserted into the housing, and the activating member is inserted into the housing via an opening in the rear cover and moves the wire terminal between open and closed positions. The wire terminal includes a clamp brace and a force applying member. A contact arm may be included in the wire terminal to connect the wire terminal to the contact member. The force applying member is used to apply a constant and continuous force or mechanical energy, e.g., a spring force, against an electrical conductor to electrically connect, clamp, secure and/or couple the electrical conductor to the clamp brace. A non-limiting example of a force applying member is a clamping member that clamps an electrical conductor against the clamp brace with constant and continuous force or mechanical energy to electrically connect the electrical conductor to the clamp brace. The activating member is used to move the force applying member or mechanical energy device between the open position permitting an electrical conductor to enter the wire terminal and the closed position clamping, coupling, securing, connecting, binding and/or squeezing the electrical conductor within the wire terminal. As noted above, the activating member may be a plunger, such as the plunger described herein, or any other structure that is configured to move the clamp spring between the open position permitting one or more electrical wires to enter the wire terminal and the closed position securing, clamping, connecting, coupling, binding and/or squeezing the one or more electrical wires within the wire terminal.
For the purposes of the present disclosure, the electrical conductor may also be referred to as the “wire.” Further, the electrical conductor can be any size wire used to conduct electricity, such as 14 AWG wire, 12 AWG wire, 10 AWG wire, 8 AWG wire or 6 AWG wire. Depending upon the number of conductors in a power cord, generally, 14 AWG wires are rated for between 15 and 18 amps, 12 AWG wires are rated for between 20 and 25 amps, 10 AWG wires are rated for between 25 and 30 amps, 8 AWG wires are rated for between 35 and 40 amps, and 6 AWG wires are rated for between 45 and 50 amps.
Referring now to
The main body 30 includes a plurality of chambers or cavities 32, seen in
As shown in
Referring to
Turning to
In this exemplary embodiment, the contact member 110 includes a contact body 112 and a pair of flexible fingers 114 and 116 extending from the contact body 112, as shown. The flexible fingers 114 and 116 form a female contact configured to engage a contact blade of a blade-type electrical power cord plug. The distal ends of the flexible fingers 114 and 116 contact each other or are in close proximity to each other to form a gripping portion 118 between the fingers 114 and 116. The gripping portion 118 is capable of receiving a contact blade so as to electrically couple or connect the contact member 110 to the contact blade. Thus, each contact assembly 100 is adapted to engage one of a plurality of contact blades of a blade-type electrical power cord plug.
The wire terminal 130 is a terminal that uses one or more force applying members that can apply mechanically generated energy to secure, clamp, connect, couple, bind and/or squeeze one or more wires, e.g., wire 700 shown in
In the embodiment described herein, the wire terminal 130 is a mechanical clamping terminal and the one or more force applying members 136 includes one or more springs that can deflect when a force or mechanical energy is applied to the one or more springs. Non-limiting examples of the one or more springs include clamp springs. The springs may also be referred to herein as “clamp springs” in the plural or “clamp spring” in the singular. In the embodiments described herein, the one or more springs can defect under a force or mechanical energy, e.g., a mechanical load, applied by the activating member 150 and recover to their initial shape when the force or mechanical energy is removed. The energy stored by the one or more clamp springs should be sufficient to apply a constant and continuous force to mechanically secure, clamp, connect and/or couple one or more wires, e.g., wire 700 shown in
In the exemplary configuration shown in
As noted, the wire terminal 130 can connect to electrical conductors of different sizes. For example, if the electrical wiring device 10 is rated for 15 amps, then the wire terminal 130 should also be configured and rated for at least 15 amps. The wire size, i.e., the bare conductor size, for 15 amps is 14 AWG wire such that the clamp arm 142 should be able to move to an open position where the outer diameter of 14 AWG wire can fit into the opening 144 of the clamp arm 142. As another example, if the electrical wiring device is rated for 20 amps, then the wire terminal 130 should also be rated for at least 20 amps. The wire size, i.e., the bare conductor size, for 20 amps is 12 AWG wire such that the clamp arm 142 should be able to move to an open position where the outer diameter of 12 AWG wire can fit into the opening 144 of the clamp arm 142. As another example, if the electrical wiring device is rated for 30 amps, then the wire terminal 130 should also be rated for at least 30 amps. The wire size, i.e., the bare conductor size, for 30 amps is 10 AWG wire such that the clamp arm 142 should be able to move to an open position where the outer diameter of 10 AWG wire can fit into the opening 144 of the clamp arm 142. As another example, if the electrical wiring device is rated for 40 amps, then the wire terminal 130 should also be rated for at least 40 amps. The wire size, i.e., the bare conductor size, for 40 amps is 8 AWG wire such that the clamp arm 142 should be able to move to an open position where the outer diameter of 8 AWG wire can fit into the opening 144 of the clamp arm 142. As another example, if the electrical wiring device is rated for 50 amps, then the wire terminal 130 should also be rated for at least 50 amps. The wire size, i.e., the bare conductor size, for 50 amps is 6 AWG wire such that the clamp arm 142 should be able to move to an open position where the outer diameter of 6 AWG wire can fit into the opening 144 of the clamp arm 142.
As noted, the spring member 140 is made of a resilient material with sufficient stiffness to flex when the activating member 150 pushes the spring member 140 from the closed position to the open position while applying a force (e.g., a spring force) or mechanical energy through the wire pressing member 146 to a wire between the wire pressing member and the clamp brace 132. As an example, the spring member 140 can be made of metal, such as spring steel. The force, e.g., spring force, or mechanical energy exerted by the spring member 140 clamping a wire 700 between the wire pressing member 146 and the clamp brace 132 should be sufficient to apply a constant and continuous force on the wire to electrically couple, secure, clamp, connect, bind and/or squeeze the wire terminal 130 to the wire, e.g., wire 700, in various temperature and environmental conditions. The spring member 140 is configured so that it is normally biased toward the closed position, i.e., in the direction of arrow “A” which is away from the clamp brace 132, as seen in
As described herein, the electrical wiring device 10 uses contact assemblies 100 to terminate electrical conductors or wires within an electrical box or enclosure. To connect wires within an electrical box or enclosure to the electrical wiring device 10, an installer, e.g., an electrician, strips the insulation from the end of each wire. In this exemplary embodiment, the electrical wiring device 10 has three contact assemblies 100 such that three wires can be connected to the electrical wiring device. However, it is also contemplated that the electrical wiring device may have less than three contact assemblies 100 or more than three contact assemblies 100. Further, it is also contemplated that each contact assembly 100 could be configured to electrically connect more than one wire to the contact assembly 100. The activating member 150 is removed from the mounting clip 152 and the distal end 150a of the activating member 150 is inserted into one of the activating member openings 80 in the housing 20 and moved, e.g., pushed vertically or horizontally, into the associated cavity 32 in the main body 30, relative to a longitudinal axis of the electrical wiring device 10 or moved relative to the clamp brace 132. For clarity, in the embodiment shown, the activating member 150 is moved in the direction of arrow “B” seen in
To remove the wires from the contact assembly 100, the activating member 150 is inserted into one of the activating member openings 80 in the housing 20 and moved, e.g., pushed vertically, relative to a longitudinal axis of the electrical wiring device 10 or moved relative to the clamp brace 132. For clarity, in the embodiment shown, the activating member 150 is moved in the direction of arrow “B” seen in
Another exemplary embodiment of a contact assembly 103 according to the present disclosure that may be used with the electrical wiring devices contemplated by the present disclosure, e.g., the electrical wiring device 10 described above, is shown in
In the exemplary embodiment shown in
In the exemplary embodiment shown in
In the exemplary embodiment shown in
In the exemplary embodiment shown in
In the exemplary embodiment shown in
While exemplary embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes, modifications, additions, and substitutions are possible, without departing from the scope and spirit of the invention.
The present disclosure is based on and claims benefit from co-pending U.S. Provisional Patent Application No. 63/320,618 filed on Mar. 16, 2022 entitled “Electrical Wiring Devices with Screwless Connection Terminals” the contents of which are incorporated herein in their entirety by reference.
Number | Date | Country | |
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63320618 | Mar 2022 | US |