BACKGROUND
Field
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.
Description of the Related Art
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.
SUMMARY
The present disclosure provides embodiments of various 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, a twist lock 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. The rear cover is removably secured to a second side of the main body and includes a plurality of wire receiving apertures and a plurality of activating member 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 apertures, from one of the plurality of activating member 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, a wire terminal and an activating member, such as a plunger. 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 force applying 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 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 positioned within one of the plurality of cavities and extends at least partially through one of the plurality of activating member openings in the rear cover. The activating member is interactive with the force applying member 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, a mechanical load, to the force applying member to cause the force applying member to move from the closed position to the open position. Further, 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 so that to the force applying member is biased from the open position to the closed position.
In an exemplary embodiment, an electrical wiring device includes a housing and at least one contact assembly. 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 at least one contact assembly is positioned at least partially in the at least one cavity so 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 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 clamp brace and the clamp member, and a second position where a wire can be inserted through one of the plurality of wire receiving openings and between the clamp brace and the clamp member. The activating member extends at least partially through the at least one activating member opening so that at least a portion of the activating member is at least partially positioned in the at least one cavity. The portion of the activating member within the at least one cavity has a camming surface that at least partially engages the force applying member so that movement of the activating member in a first direction causes the camming surface to ride along the force applying member applying a force or mechanical energy to the force applying member and causing the force applying member to move from the first position to the second position. Further 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 moves from the second position to the first position.
In another exemplary embodiment, an electrical wiring device includes a housing and a plurality of contact assemblies. The housing includes a plurality of cavities within an interior of the housing, a plurality of wire receiving openings and a plurality of activating member openings. 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 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 clamp brace and the clamp member and a second position where a wire can be inserted through one of the plurality of wire receiving openings and between the clamp brace and the clamp member. The activating member extends at least partially through the one of the plurality of activating member openings so that at least a portion of the activating member is at least partially positioned in the one of the plurality of cavities. The portion of the activating member within the one of the plurality of cavities has a camming surface that at least partially engages the force applying member so that movement of the activating member in a first direction causes the camming surface to ride along the force applying member applying a force or mechanical energy to the force applying member and causing the force applying member to move from the first position to the second position. Further 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 moves from the second position to the first position.
In another exemplary embodiment, an electrical wiring device includes a housing and at least one contact assembly. 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 at least one contact assembly is positioned at least partially in the at least one cavity so 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 clamp brace and the force applying member, and a second position where a wire can be inserted through one of the plurality of wire receiving openings and between the clamp brace and the force applying member. The activating member extends at least partially through the one of the plurality of activating member openings so that at least a portion of the activating member is at least partially positioned in the one of the plurality of cavities. The activating member has a notch and a camming surface. The notch is configured to receive at least a portion of the force applying member when in the first position and the camming surface is positioned adjacent the notch such that the camming surface is interactive with the force applying member. In this configuration, movement of the activating member in a first direction causes the camming surface to apply a force or mechanical load to the force applying member causing the force applying member to move from the first position to the second position. Further 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 moves from the second position to the first 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.
BRIEF DESCRIPTION OF THE DRAWINGS
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:
FIG. 1 is a top perspective view of an exemplary embodiment of an electrical wiring device having screwless wire terminals according to the present disclosure;
FIG. 2 is a bottom perspective view of the electrical wiring device of FIG. 1;
FIG. 3 is a bottom plan view of the electrical wiring device of FIG. 1;
FIG. 4 is a cross sectional view of the electrical wiring device of FIG. 3 taken along line 4-4;
FIG. 5 is a cross sectional view of the electrical wiring device of FIG. 3 taken along line 5-5;
FIG. 6 is a top perspective view of a rear cover of the electrical wiring device housing of FIG. 1 with three contact assemblies resting on the rear cover;
FIG. 7 is a bottom perspective view of a housing of the electrical wiring device of FIG. 1 having three cavities each housing a contact assembly;
FIG. 8 is a top perspective view of an exemplary embodiment of a screwless wire terminal for the electrical wiring device of FIG. 1 in a closed position;
FIG. 9 is a top perspective view of the screwless wire terminal of FIG. 8 in an open position;
FIG. 10 is a perspective view of another exemplary embodiment of a screwless wire terminal according to the present disclosure, illustrating an exemplary embodiment of a contact enhancing member extending from a clamp brace of the screwless wire terminal in contact with a wire clamped in the screwless wire terminal;
FIG. 11 is a side elevation view of the screwless wire terminal of FIG. 10;
FIG. 12 is a perspective of the clamp brace of FIG. 10 with the contact enhancing member extending therefrom;
FIG. 13 is a side elevation view of the clamp brace of FIG. 12;
FIG. 14 is a perspective view of another exemplary embodiment of a screwless wire terminal according to the present disclosure, illustrating another exemplary embodiment of a contact enhancing member extending from a clamp brace of the screwless wire terminal in contact with a wire clamped in the screwless wire terminal;
FIG. 15 is a side elevation view of the screwless wire terminal of FIG. 14;
FIG. 16 is a perspective of the clamp brace of FIG. 14 with the contact enhancing member extending therefrom;
FIG. 17 is a side elevation view of the clamp brace of FIG. 16;
FIG. 18 is a perspective view of another exemplary embodiment of a wire manager secured to the clamp brace, and illustrating a portion of a surface of the clamp brace with a textured surface in the form of shallow grooves;
FIG. 19 is a perspective view of another exemplary embodiment of a wire manager according to the present disclosure, illustrating the wire manager associated with a clamp brace of a wire terminal; and
FIG. 20 is a perspective view of another exemplary embodiment of a wire manager according to the present disclosure, illustrating the wire manager associated with a wire pressing member of a force applying member of a wire terminal.
DETAILED DESCRIPTION
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, 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 receptacle 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, a wire terminal and an activating member. 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 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, e.g., spring force, against an electrical conductor to electrically connect, clamp, secure, couple, bind and/or squeeze 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 between the open position permitting an electrical conductor to enter the wire terminal and the closed position securing, clamping, connecting, coupling, binding and/or squeezing the electrical conductor within the wire terminal. The activating member may be a plunger, such as the plunger described herein, or any other structure that is configured to move the force applying member 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 or 8 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 FIGS. 1-9, an exemplary embodiment of a locking electrical receptacle as the electrical wiring device is shown. In this exemplary embodiment, the electrical wiring device 10 has a housing 20 and a plurality of contact assemblies 100, seen in detail in FIGS. 8 and 9, within the housing 20 that are accessible from an exterior of the housing. The housing 20 has a main body 30, a front cover 50 and a rear cover 70. The front cover 50 is secured to one side of the main body 30 and the rear cover 70 is secured to the other side of the main body 30. The housing 20 is made of suitably rigid electrical insulating materials, such as plastic materials and is configured to fit within an electrical box or enclosure. Non-limiting examples of plastic materials include injection molded thermoplastics, such as Nylon.
The main body 30 includes a plurality of chambers or cavities 32, seen in FIGS. 4 and 5. Each cavity 32 is configured to receive and position a contact assembly 100 within the main body 30, as shown in FIGS. 6 and 7. Each contact assembly 100 is configured to receive a wire, such as wire 700 shown in FIG. 5, and to mate with a contact blade of a plug connector, such as the plug connector of FIG. 17.
As shown in FIG. 1, the front cover 50 of the electrical wiring device 10 includes a face 52 having a plurality of blade-receiving slots or openings 54 through which contact blades of a plug connector, such as the contact blades of the plug connector shown in FIG. 17, can be inserted in the usual manner into adjacent cavities 32 within the main body 30. The front cover 50 has one or more mounting straps 56 that are secured to an exterior surface of the front cover using, for example, mechanical fasteners or adhesives. The mounting straps 56 are used to secure the electrical wiring device 10 to an electrical box via apertures 58 as is known. The mounting straps 56 may also be connected to electrical ground via a contact assembly 100 within the main body 30. The front cover 50 can be secured to the main body 30 using mechanical fasteners, adhesives or welds such as sonic welds.
Referring to FIGS. 2, 3 and 5, the rear cover 70 can be secured to the main body 30 using mechanical fasteners, such as screws 72, adhesives or welds such as sonic welds. The rear cover 70 includes a plurality of wire receiving apertures 74. Each wire receiving aperture 74 is positioned to align with a cavity 32 in the main body 30 so that a wire can pass through the rear cover 70 into a contact assembly 100 resting within a cavity 32 in the main body 30. The rear cover 70 may also include a plurality of wire guides 76 extending outwardly from an exterior surface 78 of the rear cover 70, as shown. In the embodiment shown, one wire guide 76 corresponds to one wire receiving aperture 74. Each wire guide 76 has an arcuate shape that corresponds to the round shape of a wire being inserted into the wire receiving aperture 74. The rear cover 70 also includes a plurality of activating member openings 80, seen in FIGS. 2 and 3, that permits a portion of an activating member 150, forming a portion of the contact assembly 100 described below, to extend outside the housing 20.
Turning to FIGS. 8 and 9, an exemplary embodiment of a contact assembly 100 according to the present disclosure is shown. In this exemplary embodiment, the contact assembly 100 includes a contact member 110 and a wire terminal 130. The contact member 110 is made of an electrically conductive material, such as brass, copper or aluminum. The wire terminal 130 is made of at least partially of an electrically conductive material, such as brass, copper or aluminum. The wire terminal 130 may also be made at least partially of a resilient material with sufficient stiffness to flex when a force or mechanical energy, e.g., a mechanical load, is applied and can return, e.g., automatically return, to its normal position when the force or mechanical energy is removed. An example of such a resilient material is spring steel. The activating member 150 is made of suitably rigid electrical insulating materials, such as plastic materials. Non-limiting examples of plastic materials include injection molded thermoplastics, such as Nylon. The contact member 110 and the wire terminal 130 can be formed as a unitary structure, or the contact member and wire terminal 130 can be individual components secured together by, for example, a solder joint, a brazed joint, or a welded joint. The activating member 150 is provided and is configured to interact with the respective wire terminal 130 to secure, clamp, connect, couple, bind and/or squeeze one or more wires to the wire terminal.
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, such as a contact blade of the plug shown in FIG. 17. 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. 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 FIG. 5, to the wire terminal 130, and that can be released to permit the one or more wires to be inserted into or removed from the wire terminal 130. The energy stored by the one or more force applying members 136 should be sufficient to apply a constant and continuous force to mechanically secure, connect, couple or clamp the one or more wires, e.g., wire 700 shown in FIG. 5, to the wire terminal 130. In the exemplary 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 136 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, couple, bind and/or squeeze one or more wires, e.g., wire 700 shown in FIG. 5, to the wire terminal 130. A non-limiting example of the constant and continuous force against an electrical conductor to electrically connect the electrical conductor to the clamp brace is in the range of about 5 pounds force and about 35 pounds force.
In the exemplary configuration shown in FIGS. 8 and 9, the wire terminal 130 includes a clamp brace 132 and a force applying member 136. The clamp brace 132 is an electrically conductive fixed terminal body that may be a substantially planar shaped member, or an arcuate shaped member. The contact body 112 or the wire terminal 130 may include a contact arm 134. In either instance, the clamp brace 132 may be secured to the contact body 112 of the contact member 110 via the contact arm 134. The contact arm 134 also provides an electrically conductive path between the contact member 110 and at least a portion of the wire terminal 130, e.g., the clamp brace. The force applying member 136 includes an end portion 138, a spring member 140 and a clamp arm 142. As noted, the clamp spring 136 is an exemplary embodiment of a force applying member described above. The end portion 138 can be a substantially planar shaped member or an arcuate shaped member that is configured to mate with the clamp brace 132 and is secured to the clamp brace by, for example, mechanically fitting, e.g., clipping, the end portion 138 to the clamp brace 132, or by soldering, brazing, or welding the end portion 138 to the clamp brace 132. The spring member 140 has a first lobe 140a and a second lobe 140b. The first lobe 140a and the second lobe 140b are configured to interact with the activating member 150 so that movement, e.g., vertical or horizontal movement, of the activating member 150 relative to the spring member 140 is translated to the application of a force or mechanical energy, e.g., a mechanical load, on the spring member 140 or the removal of the force or mechanical energy on the spring member 140. For example, the activating member 150 can be a shaped member, such as a symmetrically or asymmetrically shaped member, e.g., a generally rectangular shaped member, having a notch 152, seen in FIG. 9, that is configured to receive the second lobe 140b of the spring member 140, as shown in FIG. 8. The notch 152 is preferably configured to receive the lower and upper lobes 140a and 140b of the spring member 140 so that when the first and second lobes 140a and 140b are within the notch 152, the spring member 140 is in the closed position. The notch 152 has a camming surface 152a that rides along the second lobe 140b of the spring member 140 when the activating member 150 is moved in the direction of arrow “B” applying mechanical energy or a force on the spring member 140 causing the spring member 140 to deflect in the direction of arrow “C” toward the open position, seen in FIG. 9.
The clamp arm 142 extends from the second lobe 140b of the spring member 140 toward the clamp brace 132, as shown. The clamp arm 142 has an elongated opening 144 configured to receive a portion of the clamp brace 132 and a wire pressing member 146 that contacts a wire, e.g., wire 700 seen in FIG. 5, positioned between the clamp brace 132 and the wire pressing member 146 when the force applying member 136 is in the closed position. The wire pressing member 146 may also be referred to herein as a tang. The clamp arm 142 is movable relative to the clamp brace 132 between the closed position, seen in FIG. 8, and the open position, seen in FIG. 9.
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 an electrically conductive 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 mechanical energy or a force (e.g., a spring force) through the wire pressing member 146 to a wire between the wire pressing member 146 and the clamp brace 132. As an example, the spring member 140 can be made of metal, such as spring steel. The mechanical energy or force (e.g., spring force) exerted by the spring member 140 clamping a wire 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 secure, clamp, couple or connect 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 FIG. 8. In the spring member's normal position without a conductor inserted into the elongated opening 144, the wire pressing member 146 of the clamp arm 142 can contact the clamp brace 132.
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 10. 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 members 150 for each contact assembly 100 extending through housing 20 are then moved, e.g., pushed vertically or horizontally, 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 FIG. 8, to cause the camming surface 152a of the notch 152 in the activating member 150 to ride along the spring member 140 applying a force or mechanical energy on the spring member 140 causing the spring member 140 to deflect in the direction of arrow “C” from the closed position toward the open position, seen in FIG. 9. With the wire terminals 130 in the open position, the electrical wires are then inserted into the appropriate wire receiving aperture 74 in the housing 20 of the electrical wiring device 10. The wire receiving apertures 74 and wire guides 76 guide the bare end of the wires into the portion of the elongated opening 144 of the force applying member 136 between clamp brace 132 and wire pressing member 146. When the bare end of each wire is positioned between the clamp brace 132 and the wire pressing member 146, the respective activating member 150 is then moved, e.g., pulled vertically or horizontally, 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 “D,” removing the force or mechanical energy applied by the activating member 150 on the spring member 140 so that the energy stored by the spring member 140 moves the spring member 140 to the closed position securing, clamping, coupling and/or connecting the wire 700 between the clamp brace 132 and the wire pressing member 146 completing an electrically conductive path between the wire and the contact member 110.
To remove the wires from the contact assembly 100, the activating members 150 for each contact assembly 100 extending through the rear cover 70 are moved, e.g., pushed vertically or horizontally, relative to a longitudinal axis of the electrical wiring device 10 or is moved relative to the clamp brace 132 to cause the camming surface 152a of the notch 152 in the activating member 150 to ride along the spring member 140 applying mechanical energy or a force on the spring member 140 causing the spring member 140 to deflect from the closed position to the open position. With the wire terminals 130 in the open position, the electrical wires can be removed from the electrical wiring device.
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 FIGS. 10-15. The contact assembly 103 is substantially similar to the contact assembly 100 such that like reference numerals are used to reference like components. The contact assembly 103 includes the contact member 110, the wire terminal 130 and the activating member 150. For ease of description, the activating member 150 is not shown in FIGS. 10, 11 and 14. The wire terminal 130 includes the clamp brace 132 and the force applying member 136. A contact arm 134 may be connected between the contact member 110 and the clamp brace 132. In this exemplary embodiment, the clamp brace 132 has a wire manager 900 integrally or monolithically formed into the clamp brace 132. In another embodiment, the wire manager 900 may be secured to the clamp brace 132 by, for example, a solder joint, a brazed joint or a welded joint. The wire manager 900 is provided to urge the wire, which may be stranded wire 710 or solid wire 700, so that the wire is concentrated toward a center or middle of the clamp brace 132 and/or a center or middle of the wire pressing member 146. Preferably, the wire manager 900 is provided to urge stranded wire 710 so that the wire strands are concentrated toward a center or middle the clamp brace 132 and/or a center or middle of the wire pressing member 146. Concentrating the strands of stranded wire 710 toward a middle the clamp brace 132 and/or a middle of the wire pressing member 146 increases the force or mechanical energy applied by the wire pressing member 146 of the clamp arm 142 of the force applying member 136 to the wire. For example, concentrating the wire 710 toward a middle the clamp brace 132 and/or a middle of the wire pressing member 146 can increase the force or mechanical energy applied by the wire pressing member 146 by, for example, about 20 percent when compared to instances where the stranded wire 710 is not concentrated wire toward a center or middle the clamp brace 132 and/or a center or middle of the wire pressing member 146. This results in a higher wire retention force in the range of about 1 pound force and about 7 pound force that can be applied by the force applying member 136 to hold the wire, e.g., the wire strands of the stranded wire 710, against the clamp brace 132. To illustrate, in the example where the energy stored by the one or more force applying members 136 should be sufficient to apply a constant and continuous force, the force should be in the range of, for example, about 5 pound force to about 35 pound force. In such an example, the higher wire retention force would be in the range of, for example, 6 pound force to about 42 pound force. In addition, the higher force or mechanical energy on the wire 710 also provides an improved electrical connection by lowering the contact resistance. Exemplary embodiments of the wire manager 900 are shown in FIGS. 16-20 and are described herein below. However, the present disclosure contemplates other wire manager embodiments where the wire manager urges a wire or wire strands toward a center or middle of a clamp brace and/or a center or middle of the wire pressing member.
In the exemplary embodiment shown in FIG. 16, the wire manager 900 is a V-shape like structure formed with a pair of wedges 902 and 904 joined by a rounded valley 906. The wedges 902 and 904 may be symmetrically shaped wedges or asymmetrically shaped wedges. In the embodiment shown, the wedges 902 and 904 are symmetrically shaped wedges having a height “H” and a width “W.” Preferably, the height “H” is in the range of, for example, about 0.05″ and about 0.15″, and the width “W” is in the range of, for example, about 0.1″ and about 0.2″. The wire manager 900 may extend along an entire width “W2” of the clamp brace 132 or the wire manager 900 may extend along a portion of the width “W2” of the clamp brace 132. In the embodiment shown, the wire manager 900 extends along the entire width “W2” of the clamp brace 132 with the rounded valley 906 positioned at or in close proximity to a center line “C” of the clamp brace 132. The wire manager 900 is also positioned on the clamp brace 132 so that the wire manager 900 does not interfere with the wire pressing member 146 contacting the exposed conductor of the wire, e.g., the strands of the stranded wire 710. For example, the wire manager 900 may be positioned so that the wire manager 900 is in close proximity to a contact line “C2,” seen in FIG. 10, were a distal end 146a of the wire pressing member 146 would contact the clamp brace 132 when the clamp brace is in the closed position and no wire is inserted into the elongated opening 144 of the wire terminal 130. In addition, a contact area 910 of the clamp brace 132 may include a textured surface 912 that is provided to grip the exposed wire strands or solid wire, e.g., the exposed strands of stranded wire 710, to improve the wire retention force applied to the exposed wire strands or solid wire by the wire pressing member 146. The contact area 910 is at least a portion of the clamp brace 132 where the wire pressing member 146 would contact the clamp brace 132 when the clamp brace is in the closed position and no wire 700 or 710 is inserted into the elongated opening 144 of the wire terminal 130. In the embodiment of FIG. 16, the textured surface 912 is striations.
In the exemplary embodiment shown in FIG. 17, the wire manager 900 is also a V-shape like structure formed with a pair of wedges 902 and 904. However, in the embodiment of FIG. 17, the wedges 902 and 904 are joined at their narrow end forming a sharp valley 906, as shown. The wedges 902 and 904 may be symmetrically shaped wedges or asymmetrically shaped wedges. In the embodiment shown, the wedges 902 and 904 are symmetrically shaped wedges having a height “H” and a width “W.” As a non-limiting example, the height “H” may be in the range of, for example, about 0.05″ and about 0.15″, and the width “W” may be in the range of, for example, about 0.1″ and about 0.2″. The wire manager 900 may extend along an entire width “W2” of the clamp brace 132 or the wire manager 900 may extend along a portion of the width “W2” of the clamp brace 132. In the embodiment shown, the wire manager 900 extends along the entire width “W2” of the clamp brace 132 with the sharp valley 906 positioned at or in close proximity to the center line “C” of the clamp brace 132. The wire manager 900 is also positioned on the clamp brace 132 so that the wire manager 900 does not interfere with the clamp member 146 contacting the exposed conductor of the wire, e.g., the strands of the stranded wire 710. For example, the wire manager 900 may be positioned so that the wire manager 900 is in close proximity to the contact line “C2,” shown in FIG. 10, were the distal end 146a of the wire pressing member 146 would contact the clamp brace 132 when the clamp brace is in the closed position and no wire is inserted into the elongated opening 144 of the wire terminal 130. In addition, a contact area 910 of the clamp brace 132 may include the textured surface 912 that is provided to grip the exposed wire strands or solid wire, e.g., the exposed strands of stranded wire 710, to improve the wire retention force applied to the exposed wire strands by the wire pressing member 146. The contact area 910 is at least a portion of the clamp brace 132 where the wire pressing member 146 would contact the clamp brace 132 when the clamp brace is in the closed position and no wire is inserted into the elongated opening 144 of the wire terminal 130. In the embodiment of FIG. 17, the textured surface 912 is knurling.
In the exemplary embodiment shown in FIG. 18, the wire manager 900 is also a V-shape like structure formed with a pair of wedges 902 and 904. However, in the embodiment of FIG. 18, the wedges 902 and 904 are spaced apart so that a portion of the clamp brace 132 forms the valley 906, as shown. The wedges 902 and 904 may be symmetrically shaped wedges or asymmetrically shaped wedges. In the embodiment shown, the wedges 902 and 904 are symmetrically shaped wedges having a height “H” and a width “W.” As a non-limiting example, the height “H” may be in the range of, for example, about 0.05″ and about 0.15″, and the width “W” may be in the range of, for example, about 0.1″ and about 0.2″. The wire manager 900 may extend along an entire width “W2” of the clamp brace 132, or the wire manager 900 may extend along a portion of the width “W2” of the clamp brace 132. In the embodiment shown, the wire manager 900 extends along a portion of the width “W2” of the clamp brace 132 with the portion of the clamp brace forming the valley 906. Preferably, the valley 906 is positioned at or in close proximity to a center or middle of the clamp brace 132. The wire manager 900 is also positioned on the clamp brace 132 so that the wire manager 900 does not interfere with the wire pressing member 146 contacting the exposed conductor of the wire, e.g., the strands of the stranded wire 710. For example, the wire manager 900 may be positioned so that the wire manager 900 is in close proximity to the contact line “C2,” shown in FIG. 10, where the distal end 146a of the wire pressing member 146 would contact the clamp brace 132 when the clamp brace is in the closed position and no wire is inserted into the elongated opening 144 of the wire terminal 130. In addition, a contact area 910 of the clamp brace 132 may include the textured surface 912 that is provided to grip the exposed wire strands or solid wire, e.g., the exposed strands of stranded wire 710, to improve the wire retention force applied to the exposed wire strands by the wire pressing member 146. The contact area 910 includes at least a portion of the clamp brace 132 where the wire pressing member 146 would contact the clamp brace 132 when the clamp brace is in the closed position and no wire is inserted into the elongated opening 144 of the wire terminal 130. In the embodiment of FIG. 18, the textured surface 912 is narrow grooves.
In the exemplary embodiment shown in FIG. 19, the wire manager 900 is a U-shape like structure formed with a pair of side walls 914 and 916, and a bottom wall 918 joined to the side walls 914 and 916 and forming a wire receiving opening or channel 920. In the embodiment shown, the side walls 914 and 916 and bottom wall have a height “H2,” a width “W2,” and a length “L2.” As a non-limiting example, the height “H2” may be in the range of, for example, about 0.05″ and about 0.15″, the width “W2” may be in the range of, for example, about 0.1″ and about 0.2″, and the length “L2” may be in the range of about 0.1″ and about 0.3″. The wire manager 900 is positioned on the clamp brace 132 so that the wire receiving opening 920 extends in a direction that is substantially parallel to a longitudinal axis of the clamp brace 132 as shown. The wire manager 900 is also positioned on the clamp brace 132 so that the wire manager 900 does not interfere with the wire pressing member 146 contacting the exposed conductor of the wire, e.g., the strands of the stranded wire 710. For example, the wire manager 900 may be positioned so that the wire manager 900 is in close proximity to the contact line “C2,” shown in FIG. 10, where a distal end 146a of the wire pressing member 146 would contact the clamp brace 132 when the clamp brace is in the closed position and no wire is inserted into the elongated opening 144 of the wire terminal 130. In addition, the contact area 910 of the clamp brace 132 may include the textured surface 912 that is provided to grip the exposed wire strands or solid wire, e.g., the exposed strands of stranded wire 710, to improve the wire retention force applied to the exposed wire strands by the wire pressing member 146. In this embodiment, the contact area 910 is at least a portion of the clamp brace 132 where the exposed conductors of, for example, the stranded wire 710, would contact the clamp brace 132 when the clamp brace is in the closed position. As described above, the textured surface 912 may be, for example, striations, knurling and/or small grooves on the surface of the clamp brace 132.
In the exemplary embodiment shown in FIG. 20, the wire manager 900 is an arcuate shape or C-shaped like structure having a wire receiving opening 920. In the embodiment shown, the sides 914 and 916 and bottom have a height “H3,” a width “W3,” and a length “L3.” As a non-limiting example, the height “H3” may be in the range of, for example, about 0.05″ and about 0.15″, the width “W3” may be in the range of, for example, about 0.1″ and about 0.2″, and the length “L3” may be in the range of, for example about 0.1″ and about 0.3″. In this exemplary embodiment, the wire manager 900 is positioned on the wire pressing member 146 so that the wire receiving opening 920 extends in a direction that is substantially parallel to a longitudinal axis of the wire pressing member 146 as shown. It is noted that the wedges 902 and 904, and the U-shaped wire managers 900 described above, and any other suitable wire managers may be substituted for the arcuate shape or C-shaped like structure on the wire pressing member 146. In addition, the contact area 910 of the clamp brace 132 may include the textured surface 912 that is provided to grip the exposed wire strands or solid wire, e.g., the exposed strands of stranded wire 710, to improve the wire retention force applied to the exposed conductors of the solid wire 700 or the stranded wire 710 by the wire pressing member 146. In this embodiment, the contact area is at least a portion of the clamp brace 132 where the exposed conductors of, for example the stranded wire 710, would contact the clamp brace 132 when the clamp brace is in the closed position. As described above, the textured surface 910 may be, for example, striations, knurling and/or small grooves on the surface of the clamp brace 132.
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.
Patent Application
20230299509
