Abstract:
A system and method of preventing an unwanted release of wires from a poke in style connector is disclosed. The system and method are designed to prevent wires that can be removed from connectors by simultaneous twisting and pulling force from being released. The system and method operate by bundling at least two wires together to prevent the wires from rotating proximate to the connector.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention is directed to wire retention system and method for preventing wires inserted into electrical connectors from accidentally releasing. The invention also provides for a label to be applied to a wire retention system proximate to the point of insertion into a connector. 
       BACKGROUND OF THE INVENTION 
       [0002]    At present, electrical wires are attached to poke-in connectors by inserting a wire end into an opening of the connector where the wire is engaged by a force to hold or lock the wire into place. The engagement of the wire may be by a lance, spring or other tensioning mechanism within the connector. 
         [0003]    These wires may release from the connector if the wire is simultaneously pulled away from the connector and twisted. Thus, connectors that are capable of releasing wires by a pull and twist force may have their wires accidentally released if these forces are applied to the wires unintentionally. 
         [0004]    Therefore, there is a need to provide a wire retention system and method to prevent the accidental release of wires from poke-in connectors from simultaneously twisting the wires while the wire is being pulled away from the connector. 
       SUMMARY OF THE INVENTION 
       [0005]    This invention is a retaining system and method for preventing the accidental release of wires from a poke-in connector that may release wires upon simultaneous pulling and twisting of wires therefrom. The system and method performs by bundling at least two wires proximate to the point of insertion into the connector. In this manner, if a pulling force away from the connector is accidentally applied to the wires and the wires are twisted, the wires are unable to rotate relative to the connector and thus prevented from accidental release from the connector. As used herein, the twisting of the wires simultaneously with the pulling in a direction away from the connector occurs around a point lying approximately axially aligned with the path of the wires into the connector. 
         [0006]    The connector is a poke-in connector type that secures a stripped lead of a wire by inserting the wire lead into the connector and engaging the wire lead with an engaging mechanism that physically and electrically engages the wire within the connector without soldering. The connector provides an electrical connection to at least one other secured wire. 
         [0007]    The system and method may be applied to wires of any diameter, and has shown to be effective for 12 to 20 gauge wire with corresponding diameters of about 0.03 inches to about 0.06 inches, although it is within the scope of the invention to apply the method to wires of lesser or greater diameter. At least two wires are bundled to prevent twisting, but it is within the scope of the invention to bundle any number of wires greater than two. 
         [0008]    The wires may be bundled proximate to the connector by several methods. In a first embodiment of the retention system and method, a sleeve is placed around at least two wires proximate to the point where the wires enter the connector. The sleeve is of a sufficient length, applied proximate to the point where the wires enter the connector, and applied in such a manner so as to prevent the wires from rotating relative to the connector at the point where the wires enter the connector when the wires are twisted while being pulled from the connector. The sleeve must be tightly placed around the bundled wires so as to allow little or no relative movement between the wires. In such a manner, the wires are secured and prevented from becoming released from the connector. 
         [0009]    For 12 to 20 gauge wire, a sleeve of a length of greater than about 0.5 inches may be applied to two or more wires at a distance of less than about 0.75 inches from the point where the wires enter the connector to prevent the wires form becoming disconnected from the connector. The sleeve is preferably located from about 0.25 inches to about 0.75 inches from where the wires enter the connector. A sleeve length of greater than about 0.5 inches may be used. A sleeve length of between about 0.5 inches and 0.75 inches is preferred. 
         [0010]    The sleeve may be formed of any wrapping material capable of remaining tightly bound to the wires while a twisting force is applied to the wires. Suitable wrapping materials included shrink wrap tubing and wire label tape. 
         [0011]    The sleeve may be formed of a shrink wrap material such as polyvinyl chloride (PVC), a high temperature fluoropolymer, a polyolefin, and neoprene. For example, the tubing may be a flexible polyolefin tubing such as ShrinkMark produced by Tyco Electronics Corporation of Middletown, Pa. 
         [0012]    The sleeve may also be formed of a wire label tape formed of polyester, vinyl, and polyamide. For example the wire label tape may be a thermal transfer printable clear polyester film with permanent acrylic adhesive such as CP Clear Polyester produced by Tyco Electronics Corporation of Middletown, Pa. 
         [0013]    In a second embodiment of the invention, the wires may be bundled by a wire tie. The wire tie must be tightly placed around the bundled wires so as to allow little or no relative movement between the wires. The wire tie may be formed of a polyamide such as Nylon or other similar material. The wire tie is formed with an end receiver for receiving the other end of the wire tie and ribbing along the wire tie such that when the free end is passed through the receiver end, the wire tie may be ratcheted down tight around the wires. The wire tie may be ratcheted down by hand or by a tightening device. More than one wire tie may be applied adjacent or in close proximity to increase the axial length of coverage along the wires. The wire tie may be a polyamide cable tie such as AMP-TY Nylon Cable Ties in about 0.2 width produced by Tyco Electronics Corporation of Middletown, Pa. 
         [0014]    Wire ties have a greater stiffness compared to the above disclosed sleeves due to the greater thickness of the wire tie. The width of the wire tie is analogous to the length of the wire sleeve, both measured as the axial coverage of the wires. Because of the increased stiffness, the wire tie may provide less axial coverage of the wires compared to the wire sleeve. Specifically, a wire tie with a width of about 0.05 or greater may be applied less than about 0.75 inches from the point where the wires enter the connector to prevent the wires from rotating relative to the connector proximate to the point where the wires enter the connector. In such a manner, the wires will be prevented from releasing from the connector when the wires are twisted while pulled from the connector. A wire tie with a width of about 0.1 inches to about 0.5 inches is preferred. A wire tie may be placed less than 0.75 inches from the point where the wires enter the connector, and are preferably placed less than about 0.5 inches from the point where the wires enter the connector. 
         [0015]    In a third embodiment of the invention, at least two wires are twisted around one another proximate to the point where the wires enter the connector. The wires are twisted in such a manner so as to prevent the wires from rotating relative to the connector proximate to the point where the wires enter the connector. For two or more wires, the wires may be twisted around one another or braided so as to prevent rotation. For 12 to 20 gauge wire, wires that have been twisted 2 or more times around one another from less than about 0.75 inches from the point where the wires enter the connector have secured the wires from being disconnected from a connector when being pulled and twisted from the connector. 
         [0016]    In a fourth embodiment of the invention, a label, mark or color is incorporated into the wrapping material so as to allow identifying or description terms or symbols to be applied to the wires proximate to the point where the wires enter the connector. The label may be incorporated into the wrapping material prior to application to the wires or may be incorporated or printed upon the wrapping material after the wrapping material has been applied to the wires. For example, wire label tape with preprinted information may be a thermal transfer printable clear polyester film with permanent acrylic adhesive such as CP Clear Polyester produced by Tyco Electronics Corporation of Middletown, Pa. 
         [0017]    Further aspects of the method and system are disclosed herein. The features as discussed above, as well as other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  illustrates an embodiment of the wire retaining system and method of the current invention. 
           [0019]      FIG. 2  illustrates a second embodiment of the wire retaining system and method of the current. 
           [0020]      FIG. 3  illustrates a third embodiment of the current invention incorporating a label into the wire retaining system and method. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    The present invention now will be described more fully hereinafter with reference to the accompanying drawing, in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. 
         [0022]    Referring to  FIG. 1 , according to the first embodiment of the invention, a retaining system  10  for preventing the accidental release of two or more wires from a poke-in connector  20  is shown. The retaining system  10  includes a poke-in connector  20  for electrically connecting wires, input wires  30 , output wires  40 , and a pair of wire bundling sleeves  50 . The input wires  30  and output wires  40  are formed of  18  gauge wire. 
         [0023]    A first wire bundling sleeve  50  was placed around the input wires  30 . A second wire bundling sleeve  50  was placed around the output wires  40 . The sleeves were formed of 0.5 inches lengths of polyolefin tubing manufactured under the name ShrinkMark produced by Tyco Electronics Corporation of Middletown, Pa. The sleeves were slid over the wires and heated to shrink the sleeve securely around the wires. Both sleeves  50  were placed approximately 0.5 inches from the point where the input wires  30  and output wires  40  enter the connector  20 . 
         [0024]    The sleeves  50  prevented the input wires  30  and the output wires  40  from substantially rotating proximate to the point where the wires enter the connector  20  when the wires were twisted while a pulling force was applied to the wires and prevented the input wires  30  and the output wires  40  from becoming disconnected from the wire connector  20 . 
         [0025]    In accordance with a second embodiment of the invention, wire ties were placed around the input and output wires as in the first embodiment. In this embodiment, the wire ties were AMP-TY Nylon Cable Ties in 0.236 width produced by Tyco Electronics Corporation of Middletown, Pa. The wire ties were placed about 0.5 inches from the point where the wires entered the connector. 
         [0026]    The wire ties prevented the input and output wires from substantially rotating proximate to the point where the wires enter the connector when the wires were twisted while a pulling force was applied to the wires and prevented the input and output wires from becoming disconnected from the wire connector. 
         [0027]    A third embodiment of the invention is illustrated in  FIG. 2 . As shown in  FIG. 2 , a second retaining system  200  was formed of a poke in connector  220 , input wires  230 , output wires  240 , and wire twist sections  250 . The input wires  230  were prevented from disconnecting from the connector  220  by the wire twist section  250 . The wire twist section  250  bundled the input wires  230  and output wires  240  proximate to a point where the wires entered the connector  220 . The wire twist section  250  was formed by twisting two  18  gauge wires that formed the input wires  230  around one another twice proximate to the point where the input wires  230  entered the connector  220 . The other wire twist section  250  was formed by twisting two 18 gauge wires that formed the output wires  230  proximate to the point where the output wires  240  entered the connector  220 . 
         [0028]    The wire twist sections prevented the input wires  230  and output wires  240  from substantially rotating proximate to the point where the wires enter the connector when the wires were twisted while a pulling force was applied to the wires and prevented the input wires  230  and the output wires  240  from becoming disconnected from the connector  220 . 
         [0029]    A fourth embodiment of the invention is shown in  FIG. 3 . As illustrated in  FIG. 3 , a third retaining system  300  was formed of a poke-in connector  320 , input wires  330 , output wires  340 , and a pair of wire bundling sleeves  350 . A wire bundling sleeve  350  was placed around the input wires  330  and another wire bundling sleeve  350  was placed around the output wires  340  to prevent the wires form disconnecting from the connector  320  when the wires  340  are pulled in a direction away from the connector  320  while simultaneously twisted. The sleeve  350  incorporated an identifier  360  to mark the wires  330  that have been bundled. The identifier  360  was a label. 
         [0030]    In this embodiment, the bundling sleeve  350  was formed of shrink wrap tubing incorporating the identifier  360  formed of a polyolefin tubing manufactured under the name ShrinkMark produced by Tyco Electronics Corporation of Middletown, Pa. The shrink wrap tubing forming the sleeve  350  was formed around the wires  330  by conventional sliding the sleeve  350  over the wires and heating with a heat gun until the shrink wrap tubing tightly bundled the wires. The sleeves  350  were approximately  0 . 5  inches long and prevented the wires from substantially rotating at the point where the wires enter the connector  320  and prevented the input wires  330  and the output wires  340  from becoming disconnected from the connector  320 . 
         [0031]    While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.