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 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 openings, 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. 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 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, e.g., a mechanical load, to the force applying member to cause the force applying member to move from the closed position to the 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 so that to the force applying member is moved from the open position to the closed position.
In another exemplary embodiment, the electrical wiring device includes a housing and a plurality of contact assemblies. The housing has a plurality of cavities within an interior of the housing, a plurality of cam members, a plurality of wire receiving openings and a plurality of activating member openings. Preferably, one of the plurality of cam members is positioned within one of the plurality of cavities. In this configuration, one of the plurality of contact assemblies are 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 has a clamp brace and a force applying member secured to the clamp brace. The force applying member is movable, e.g., 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 one of the plurality of wire receiving openings and between the force applying member and the clamp brace. In another embodiment, when the force applying member is in the first position, the wire is secured between the force applying member and the clamp brace by clamping the wire between the force applying member and the clamp brace. The activating member is at least partially positioned in the one of the plurality of cavities such that the activating member is at least partially operatively associated with the one of the plurality of cam members and extends at least partially through the one of the plurality of activating member openings. The activating member is interactive with the force applying member such that movement of the activating member in a first direction, e.g., movement relative to the clamp brace, the housing and/or the force applying member, causes the activating member to move along the one of the plurality of cam members such that the activating member applies a force or mechanical energy to the force applying member. Applying a force or mechanical energy to the force applying member causes the force applying member to move from the first position to the second 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 so that the force applying member can move, e.g., move automatically, from the second position to the first position.
In another exemplary embodiment, the electrical wiring device includes a housing and a plurality of contact assemblies. The housing has a plurality of cavities within an interior of the housing, a plurality of cam members, a plurality of wire receiving openings and a plurality of activating member openings. Preferably, one of the plurality of cam members is positioned within one of the plurality of cavities. In this configuration, one of the plurality of contact assemblies is positioned at least partially in one of the plurality of cavities such 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 has a clamp brace and a force applying member secured to the clamp brace. The force applying member is movable, e.g., 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. In another embodiment, when the force applying member is in the first position, the wire is secured between the force applying member and the clamp brace by clamping the wire between the force applying member and the clamp brace. The activating member is at least partially positioned in the one of the plurality of cavities and extends at least partially through the one of the plurality of activating member openings. The activating member has a first face and a second face. The first face is interactive with the force applying member and the second face is at least partially operatively associated with the one of the plurality of cam members, such that movement of the activating member in a first direction, e.g., movement relative to the clamp brace, the housing and/or the force applying member, causes the second face of the activating member to move along the one of the plurality of cam members causing the activating member to apply a force or mechanical energy to the force applying member. Applying a force or mechanical energy to the force applying member causes 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 another exemplary embodiment, the electrical wiring device includes a housing and a plurality of contact assemblies. The housing has a plurality of cavities within an interior of the housing, a plurality of cam members, a plurality of wire receiving openings, and a plurality of activating member openings. Preferably, one of the plurality of cam members is positioned within one of the plurality of cavities. In this configuration, one of the plurality of contact assemblies is positioned at least partially in one of the plurality of cavities such 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 has a clamp brace and a force applying member secured to the clamp brace. The force applying member is movable, e.g., 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 one of the plurality of wire receiving openings and between the force applying member and the clamp brace. The activating member is at least partially positioned in the one of the plurality of cavities and extends at least partially through the one of the plurality of activating member openings. The activating member has a first face and a second face. The first face is interactive with the force applying member, and the second face has a camming surface that is at least partially operatively associated with the one of the plurality of cam members, such that movement of the activating member in a first direction, e.g., movement relative to the clamp brace or the force applying member, the housing and/or the force applying member, causes the camming surface of the second face of the activating member to move along the one of the plurality of cam members causing the activating member to apply a force or mechanical energy to the force applying member. Applying a force or mechanical energy to the force applying member causes 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 automatically 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.
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 electrical receptacles, locking electrical receptacles, single or multi-pole electrical switches, combination switches and receptacles, plugs for electrical cords, 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. The electrical wiring devices 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 openings (hot and/or neutral contact blade openings) 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 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 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. 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 and/or coupling the one or more electrical wires within the wire terminal. The activating member openings in the housing may also be referred to herein as the “plunger openings” in the plural and the “plunger opening” in the singular. In addition, the activating member may also be referred to herein as the “plungers” in the plural and the “plunger” in the singular.
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. 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 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., a spring force, or mechanical energy 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 700 to electrically couple, clamp, secure, 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 moved 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. To connect wires 700 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 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 the housing 20 are then moved, e.g., pulled 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 members 150 are moved in the direction of arrow “B,” seen in
To remove the wires 700 from the contact assembly 100, the activating members 150 for each contact assembly 100 extending through the housing 20 are moved, e.g., pulled 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 members 150 are 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 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. 63/320,620 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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63320620 | Mar 2022 | US |