Abstract:
An electrical connection system ( 10 ) for connecting at least two electrical wires (W) together in a secure housing. A non-electrically conductive base ( 12 ) has a plurality of ports ( 16 ) corresponding to at least the number of wires being connected together with an end of each wire being inserted through a respective port. Exposed ends of the wires are then twisted together. A non-electrically conductive cap ( 14 ) is sized and shaped to align with and fit over a top of the base with the twisted together exposed ends of the wires fitting within the cap. The base and cap together form a shell in which the twisted together wires are securely enclosed.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     None 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     N/A 
     BACKGROUND OF THE INVENTION 
     This invention relates to twist-on wire connectors used in electrical systems; and, more particularly to a compact electrical connection system for twisted wires and having an electrically insulating shell. 
     There is a continuing need to conveniently connect electrical wires together in an electrical system. The most common type connector, and the one extensively used by electrical contractors and do-it-yourselfers is the “twist-on connector.” This connector is also commonly referred to as a wire nut, a cone connector, or a thimble connector. 
     The connector typically has an insulated plastic shell molded over a sharpened spring steel inner coil and is used to fasten together two or more electrical conductors. Regarding their use, electricians tend to prefer to twist electrical wires together and use an electrical tape to insulate the connection. This has the advantage of an electrician seeing that the wires are indeed twisted together and have achieved a good mechanical connection. Indeed, a practice used by many electricians who use a twist-on connector is to pre-twist the wires before using the connector so to ensure that the wires are indeed twisted together before applying the connector, this regardless of manufacturer instructions. 
     Twist-on wire connectors are available in a variety of sizes and shapes. While their exterior covering is typically an insulating plastic, their means of connection is a tapered metal coil insert, which threads onto the wires and holds them securely. When such a connector is twisted onto the stripped and twisted-together ends of wires, the wires are drawn into the connector&#39;s metal insert and squeezed together inside it. Electrical continuity is maintained by both the direct twisted wire-to-wire contact and by contact with the metal insert. Additionally, the threads cut into the wires by the tapered metal insert are what hold the twist-on wire connector onto the assembly. 
     Twist-on wire connectors are typically installed by hand and may have external grooves to make them easier to handle and apply. Wing-like extensions are commonly molded into higher quality connectors to reduce an installer&#39;s muscle fatigue when installing large numbers of connectors. Additional tools such as a common nut driver are also used to help reduce installer fatigue during the installation of a large numbers of such connectors. The connectors are commonly color-coded to indicate connector size and, hence, their capacity. They are commonly used as an alternative to terminal blocks or the soldering together of conductors since they are quicker to install and, unlike soldered connections, allow easy subsequent removal for future modifications. Twist-on connectors are not often used on wire gauges thicker than AWG #10 (5.26 mm 2 ), because these wires are too stiff to be reliably connected using this method. Instead, set screw connectors, clamps, or crimp connectors are used in these instances. 
     There are some specialized versions of twist-on connectors. Ceramic twist-on connectors, for example, are made for high-temperature applications, such as heating appliances. Ordinary twist-on connectors are not rated for wet use (such as outdoor exposure outdoors or underground burial). Special, gel-filled connectors are used in this circumstance. 
     Twist-on wire connectors are not generally recommended for use with aluminum wire. The US Consumer Product Safety Commission does not approve their use with aluminum wire, and approves only two (alternative) methods of connection. Despite this, several companies manufacture twist-on connectors which they claim are designed specifically for, and rated for, use with aluminum conductors. 
     Special feed through twist-on wire connectors differ from standard wire connectors in that they have an additional opening at the top of the insulated cap. This allows a single-conductor bare wire to be pushed through the hole, forming a “pigtail” section which is attached to a grounding screw. These feed-through connectors are commonly referred to as “screw-on grounding connectors.” For some applications, the pigtail may be unterminated, or it may end in a pre-installed spade lug. One version (colored white) is used, for example, for splicing neutral wires in a device box, while leaving the pigtail free for connection to a receptacle, for example. Another version (colored green) is used as a grounding pigtail and is similar to the feed through twist-on wire connector previously described. 
     As noted above, previous twist-on connectors are comprised of a tapered coiled metal insert surrounded by an insulating material which ranges from plastic to polymers to rubber. Typically, innovation regarding twist-on connectors relates to material changes; however, the fundamental of a coil inside an insulator is basic to all of these current connector constructions. As an example, adding gels for waterproofing is a recent innovation, but the fundamental structure of a twist-on connector is the same as in earlier constructions. 
     The most expensive part of a basic twist-on connector is the tapered coil itself and its manufacture. The sole purpose of the coil is to twist the wires together, but in doing so, it adds to the bulkiness of the connector. Since it is the practice of electricians to pre-twist the wires anyway (again, so that they can visually see they have a good, twisted, mechanical bond), the role of the tapered coil is essentially obsolete. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is directed to a connector system that still uses the electrician&#39;s practice of twisting wires together and using an insulating cover. Such a connector has all the attributes of a conventional “twist-on” connector including, but not limited to, special sealant filled connectors for use in wet applications. However, the connection system and connector of the present invention is less bulky, is easy to use, allows visible confirmation by an installer of the connection, and is less expensive to manufacture. 
     It is a feature of the present invention that it separates the action of holding a connector on the wires from the action of insulating the connection using either individual components or elements of the same component. The resulting connection has greater pull-out strength than conventional connectors, but takes up less volume. The pull-out strength is directly proportional to the amount of force required to pull the twist out of the wires, and the strength of the connection between the insulating cover and the component which slides over the wires. The end result is that the protective insulation is better attached to the connection than was previously possible. The volumetric reduction results from the connector no longer needing to house a tapered steel spring insert, nor needing to rotate freely; and, it allows a designer to use thinner material walls. As such, the shape can be more angular providing for less fill in electronics enclosures, and allowing an electrician to better “pack” the connections when compared with the circular twist-on connectors. 
     Other objects and features will be in part apparent and in part pointed out hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The accompanying figures which, together with the detailed description that follows, form part of the specification and illustrate the various embodiments described in the specification. 
         FIG. 1  is a perspective view of an assembled compact electrical twist-on connector of the connection system of the present invention; 
         FIG. 2A  is a perspective view of a base of the connector, and  FIG. 2B  is a top plan view of the base; 
         FIG. 3  is a perspective view similar to  FIG. 2A  and including a coil for sensing current flow through a wire installed in the base of the connector; 
         FIG. 4A  is a perspective view of a cap of the connector, and  FIG. 4B  is a bottom plan view thereof; 
         FIGS. 5A and 5B  illustrate assembly of the connector; 
         FIG. 6  is a view similar to  FIG. 5B  illustrating but with the base including the current sensing coil; and, 
         FIG. 7  is a block diagram for reporting operational information about the connecting system. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF INVENTION 
     The following detailed description illustrates the invention by way of example and not by way of limitation. This description clearly enables one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention. Additionally, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it will be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
     Referring to the drawings, a compact electrical connector for a connection system is indicated generally  10 . Connector  10  is used to mechanically secure the exposed ends E (see  FIGS. 5B and 6 ) of shielded electrical wires W. The exposed ends of the wires are twisted together and housed within a shell formed by the connector so to be securely enclosed within the connector. Further, connector  10  is significantly smaller in size than conventional connectors currently in use by electricians for securing together the exposed outer ends of electrical wires. While connector  10 , as shown and described herein, is for use with a three (3) wire configuration, it will be understood by those skilled in the art that other embodiments of the connector can be used, for example, with a two (2) wire installation without departing from the scope of the invention. 
     As shown in the drawings, and as described herein, connector  10  comprises two components, a base generally indicated  12 , and a cap generally indicated  14  which fits over, and interlocks with, base  12 . Both components  12  and  14  are made of a lightweight, electrically non-conductive molded plastic material. With regard to base  12 , it could be planar in form so to be fabricated by a stamping process. This could further lower the cost of the connector&#39;s manufacture. 
     Referring to  FIGS. 2A and 2B , in one embodiment base  12  is shown to be generally triangular in plan with each corner of the base being rounded. Within base  12  are three individual openings or ports  16  through which the ends of wires W are inserted as shown in  FIGS. 5A, 5B, and 6 . Extending outwardly from each side of base  12 , adjacent the bottom of the base, is a generally U-shaped, when viewed in plan, bracket  18 . An attachment arm  20  of cap  14  is inserted through the open area defined by bracket  18  and a sidewall  22  of base  14  to capture the cap and hold it in place when connector  10  is assembled as shown in  FIG. 1 . 
     It will be understood by those skilled in the art that an electrically non-conductive gasket or sealing material can be placed over, or applied to, an upper surface or inner face  24  of base  12 . For example, a non-conductive sealant material such as silicone is appropriate for waterproofing purposes. Also, base  12  could be modified to prevent any such material from flowing or being squeezed out of connector  10  as the connection system is assembled. 
     In another embodiment of the invention, a base  12 ′ shown in  FIG. 2B  is manufactured with its ports  16  having a membrane M that seals the port until punctured by the end of a wire W being inserted through the opening forming the port. This then allows electricians to make use of connectors  10  having more ports than wires used in an installation without having to manually cover unused ports in some way. This, for example, allows a three-port connector  10  to be readily used in a two wire installation. 
     Referring to  FIG. 3 , in another embodiment of the invention, an electrical coil C is installed on the inner surface of base  12  about one of the ports  16 . Coil C is a sensor coil in which an AC current is induced when electricity flows through the wires. The output from coil C is an AC current proportional to the induced voltage. As shown in  FIG. 6 , coil C surrounds the wire W inserted through this port. 
     Cap  14 , as shown in  FIGS. 4A and 4B , creates an electrically insulated internal volume in which the exposed ends E of twisted wires W are enclosed. Cap  14  keeps outside elements (water, dirt, debris, etc.) from getting into connector  10  and coming into direct contact with the exposed ends E of the wires installed in the connector. 
     Cap  14  comprises an elongate, triangular shaped, hollow cap whose outer contour, at a bottom surface  26  of the cap, see  FIG. 4B , corresponds in size and shape to upper surface  24  of base  12 . This enables the respective ends of the cap and base to align and register with each other without any overlap between them. Respective attachment arms  20  extend vertically from each side of cap  14  with the lower end of each arm extending below the bottom of the cap a sufficient distance to be received in an associated bracket  18  of base  12 . The distal end  28  of each arm  20  forms a latch so as the arm is inserted through the bracket, the latch portion of the arm is captured on (snap fits with) the underside of the bracket. This firmly locks the cap and base together. 
     Referring to  FIGS. 5A and 5B , assembly of the connection system is as follows: 
     First, the outer ends of wires W are inserted through openings  16  in base  12 , the ends of the wires being inserted through the base from the underside of the base. This is as shown in  FIG. 5A . 
     Next, the outer ends of the wires are stripped of their insulation to create exposed outer ends E. 
     Then, the exposed ends of the wires are twisted together as shown in  FIG. 5B . 
     Finally, cap  14  is aligned with base  12  and then lowered onto the base with the arms  20  being inserted through the brackets  18  until the latch portions of the arms are captured by the brackets  18  of base  12 . 
     Since the stripped portions of wires W are housed within connector system  10 , cap  14  provides, together with base  12 , effectively insulates the conductive elements (wires W) enclosed within the connector from exterior elements. Although not shown, an electrically non-conductive sealant material may be poured or injected into cap  14  to, for example, waterproof the connection. Additionally, since the wires W enter base  12  through individual ports  16 , any excess sealant will surround and encapsulate the portion of the wires adjacent the base, so that a sealant need not be manually applied the connection system after completion of the assembly. 
     Referring to  FIGS. 6, and 7 , connection system  10 , in one embodiment, comprises part of a sensor package S for reporting the status of the installation in which connector  10  is used. That is, when AC flows through the wires, an AC current is induced in coil C and the output from the coil is a level proportional to the induced current. This information is provided to a microprocessor P as indicated in  FIG. 7 . Other information is provided by the sensor package to the microprocessor includes one or more of: 
     a. temperature 
     b. humidity 
     c. system integrity (e.g. strain on the connector) 
     Outputs from the microprocessor are provided, for example, to a wireless communications device D such as a cell phone for transmission to a remote site where the status of the installation is monitored. 
     In view of the above, it will be seen that the several objects and advantages of the present disclosure have been achieved and other advantageous results have been obtained.