Abstract:
An electrical connector assembly for use in environmentally challenging locations. The electrical connector assembly comprises a receptacle connector member, a plug connector member and a coupling nut that interface to provide dual radial seals so as to define dual contaminant barriers. The dual radial seals substantially eliminate the possibility of particulate as well as moisture and water intrusion. Each connector member is individually potted to a wire to eliminate the potential for water wicking up the wire while transferring the wire pull strength to the connector member. The electrical connector can include a security seal to provide visual indication of any tampering with the electrical connector assembly. Each connector member can include a protective cover allowing the connector members to be stored for extended periods of time without degradation.

Description:
PRIORITY CLAIM 
     The present invention claims priority to U.S. Provisional Application Ser. No. 60/528,019, filed Dec. 9, 2003, entitled “Multi-Environment In-Line Connector”, and hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to an electrical connector. More particularly, the invention describes an electrical connector incorporating protective features allowing the connector to function reliably for long periods of time under a wide range of environmental conditions. 
     BACKGROUND OF THE INVENTION 
     A variety of electrical connector designs are available for use in electrically connecting components, for example sensors with transmitters. Depending upon the particular application, a user selects the appropriate connector based on any number of application-specific factors, for example, code requirements, exposure to specific environmental conditions and anticipated lifespan, to name a few. 
     An especially challenging environment for using electrical connectors is with water meters and transmitters that are located in below ground water pits. Such water pit installations are commonly used in geographic regions that are not typically subjected to freezing conditions and in which a majority of homes are generally not constructed on full slab foundations. As such, there is no basement or access space for mounting a water meter within the home. 
     Due to the nature of the application, electrical connectors used within water pits must be capable of resisting long term exposure to an environment ranging from high humidity to full submersion. In addition, the constraints associated with accessing and working within a water pit requires that the electrical connector be easy to assemble and install. 
     One known connector currently used in these types of environments is disclosed in U.S. Pat. No. 6,162,082 to Karsten et al., which is herein incorporated by reference to the extent not inconsistent with the present disclosure. While the Karsten et al. patent teaches an electrical connector for used in “wet” environments, the electrical connector suffers from the disadvantage of being permanently connected when assembled such that disassembly requires the use of a tool to fracture a locking component of the electrical connector. This locking component must then be replaced with a new locking component in order to complete the connection. 
     SUMMARY OF THE INVENTION 
     The electrical connector assembly of the invention includes features promoting both long-term reliability as well as ease of installation and maintenance. The electrical connector of the invention comprises a receptacle connector member and a plug connector member that interface to provide a dual radial seal substantially eliminating the possibility of moisture and water intrusion. Each connector member is individually potted to a wire to substantially eliminate the potential for water wicking up the wire while transferring the wire pull strength to the connector member. The receptacle connector member and plug connector member are retainably joined with a rotatably disassemblable locking member allowing for easy maintenance and reuse without the use of any tools. When connected, the electrical connector comprises dual radial seals, one to prevent dirt and contaminant infiltration, the second prevention moisture/water intrusion. The electrical connector can further comprise a security seal member to prevent and/or indicate unauthorized tampering with the electrical connector. The security seal member performs no joining or sealing function such that its size, shape and orientation can be varied so as to be economically provided without having any effect on the functionality of the electrical connector. Both the receptacle connector member and the plug connector member can further include individual protective covers allowing them to be maintained and stored for extended periods of time without degradation. 
     In one representative embodiment, the electrical connector of the invention can be used to electrically connect a water meter with a transmitter in a water pit installation, however the invention is not necessarily limited to such an application. In general, the electrical connector of the invention can be employed in conditions, ranging from high humidity to full submersion, in which a reliable connection is required between disparate electrical components. 
     In one aspect, the electrical connector of the invention comprises an improved seal design over presently available electrical connectors so as to substantially eliminate the possibility of moisture/water intrusion into the connector. 
     In another aspect, the electrical connector of the invention comprises alignment features that substantially eliminate the possibility of misassembling the electrical connector. 
     In another aspect, the electrical connector of the invention comprises assembly features allowing the electrical connector to be implemented and installed without requiring custom tools or specialized skills on the part of the installer. 
     In another aspect, the electrical connector of the invention comprises assembly features allowing the electrical connector to be factory installed to electrical devices such that field installation time is reduced. 
     In another aspect, the electrical connector of the invention comprises protective features allowing unassembled portions of the connector to be protected from moisture and water intrusion such that the connector does not experience corrosion and degradation during storage periods. 
     In another aspect, the electrical connector of the invention comprises tamper indication features that quickly and conveniently provide a visual indication of unauthorized tampering with the electrical connector. 
     In another aspect, the electrical connector of the invention comprises connecting and disconnecting features allowing the electrical connector to be repeatedly disassembled and reused without destroying the electrical connector or necessarily requiring the replacement of connector components. 
     The above summary of the various representative embodiments of the invention is not intended to describe each illustrated embodiment or every implementation of the invention. The figures in the detailed description that follow more particularly exemplify these embodiments 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which: 
         FIG. 1  is an end view of a completed electrical connection assembly utilizing an electrical connector of the invention. 
         FIG. 2  is an end view of the electrical connection assembly of  FIG. 1 . 
         FIG. 3  is a section view of the electrical connection assembly of  FIG. 1  taken along line A—A of  FIG. 1 . 
         FIG. 4  is an end view of a receptacle connector member. 
         FIG. 5  is an end view of a plug connector member. 
         FIG. 6  is a side view of the electrical connection assembly of  FIG. 1  including a security lock. 
         FIG. 7  is a pictorial representation of a typical water pit metering system. 
         FIG. 8  is a section view of an example of a water pit installation. 
         FIG. 9  is a section view of an example of a water pit installation. 
         FIG. 10  is a section view of a receptacle connector member including a protective cap. 
         FIG. 11  is a section view of a protective cap for uses with a plug connector member. 
     
    
    
     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The invention relates to electrical connectors adapted for use in a variety of environmental conditions. The electrical connector of the invention can be used reliably in a wide variety of environmental conditions including high ambient temperatures, freezing temperatures, low humidity and high humidity settings. Furthermore, the connector of the invention can be successfully utilized in situations in which the connector is exposed to water by splashing or even when completely submerged. Furthermore, the connector of the invention can be quickly installed without any special skills or tools. 
     A connector assembly  100  of the invention is depicted in  FIGS. 1 ,  2 ,  3 ,  4 , and  5 . Generally, connector assembly  100  is used to electrically connect a first cable  102  with a second cable  104 . The cables can be present in a variety of forms and will most typically include a plurality of individual wires encased within an exterior, protective casing. The cables can be supplied by any number of different manufactures, for example Belden. For purposes of describing the connector assembly  100  of the invention, first cable  102  is described as including a first wire  102   a , a second wire  102   b , and a third wire  102   c  while second cable  104  includes a first wire  104   a , a second wire  104   b , and a third wire  104   c . As shown in  FIG. 3 , connector assembly  100  is comprised of a receptacle connector member  105 , a plug connector member  106 , a first radial seal  107 , and a second radial seal  108 . In one representative example, radial seals  107 ,  108  can comprise o-rings made of a resilient rubber or rubber-like, flexible polymer such as, for example, Ethylene Propylene Diene Monomer (EPDM), nitrile (Buna-N), silicone and fluorinated polymers and copolymers. 
     Receptacle connector member  105  comprises a receptacle connector body  110  and a receptacle backshell  112 . Receptacle connector body  110  includes an outer wall  116  having an outer wall groove  118  and an outer wall thread  119 . Outer wall groove  118  is dimensioned to accommodate second radial seal  108 . Receptacle connector body  110  further comprises a receptacle locking tab  120  having a receptacle locking throughbore  122 . Receptacle connector body  110  is further defined by a receptacle mating flange  124  and a receptacle inner wall  126  comprising an inner wall flange  128 . Receptacle inner wall  126  includes a plurality of keyed projections  129  as shown in  FIG. 4 . Receptacle connector body  110  also includes a receptacle projecting end  130  including a perimeter receptacle thread  132 . Receptacle connector body  110  includes three contact throughbores  134   a ,  134   b ,  134   c , each throughbore including its own pin contact  136   a ,  136   b ,  136   c . Pin contacts  136   a ,  136   b ,  136   c  are solid except for a blind hole used to connect first wire  102   a , second wire  102   b  and third wire  102   c  such that liquid cannot wick up the wires to the pin contacts. Receptacle backshell  112  comprises a hollow member having a receptacle end  138  and a cable end  139 . Receptacle end  138  includes an internal backshell thread  140 . Receptacle end  138  is dimensioned to accommodate projecting end  130 . 
     In assembling receptacle connector member  105 , first wire  102   a , second wire  102   b  and third wire  102   c  are attached to the pin contacts  136   a ,  136   b  and  136   c  through crimping or other suitable attachment method. First cable  102  can then be slid through receptacle backshell  112 . Once first cable  102  is positioned through receptacle backshell  112 , pin contacts  136   a ,  136   b ,  136   c  are press fit into contact throughbores  134   a ,  134   b  and  134   c . Receptacle connector body  110  and receptacle backshell  112  are then threadably engaged using projection thread  132  and backshell thread  138 . Epoxy potting  141  is then injected into receptacle backshell  112  such that no voids are formed, which could allow liquid/moisture to bridge between the wires  102   a ,  102   b ,  102   c . As it cures, epoxy potting  141  adheres to first cable  102  and receptacle connector body  110 . Epoxy potting  141  eliminates any leak path between the wires ( 102   a ,  102   b ,  102   c ) and pin contacts ( 136   a ,  136   b ,  136   c ) on the backside of receptacle connector body  110 . Epoxy potting  141  also aids in increasing the tensile pull strength of connector assembly  100 . 
     Referring again to  FIGS. 1–5  and  6 , plug connector member  106  is comprised of a plug connector body  150 , a coupling nut  152  and a plug backshell  154 . Plug connector body  150  is defined by a plug outer wall  156 , a plug face  158  and a plug flange  162 . Plug outer wall  156  includes an outer wall groove  161  and a plug projection  163  having a plug thread  164 . Plug outerwall  156  further includes a plurality of keyed grooves  165  as shown in  FIG. 5  corresponding to keyed projections  129 . Plug connector body  150  includes three socket throughbores  166   a ,  166   b ,  166   c , each throughbore including its own socket contact  168   a ,  168   b ,  168   c . Socket contacts  168   a ,  168   b ,  168   c  are solid except for a blind hole used to connect first wire  104   a , second wire  104   b  and third wire  104   c  such that liquid cannot wick up the wires to the socket contacts. Coupling nut  152  includes an outer nut surface  170  and an inner nut surface  172 . Inner nut surface  172  includes an inner nut thread  174 . Coupling nut  152  further comprises a nut locking tab  178  defining a nut locking face  176 . Nut locking tab  178  includes a nut throughbore  179 . Plug backshell  154  comprises a hollow member having a plug end  180  and a cable end  182 . Plug end  180  includes an internal backshell thread  184 . Plug end  180  is dimensioned to accommodate plug projection  163 . 
     To assemble plug connector member  106 , first wire  104   a , second wire  104   b  and third wire  104   c  can be attached to the socket contacts  168   a ,  168   b  and  168   c  through crimping or other suitable attachment methods. Second cable  104  can then be slid through plug backshell  154 . Once second cable  104  is positioned through plug backshell  154 , socket contacts  168   a ,  168   b ,  168   c  are press fit into socket throughbores  166   a ,  166   b ,  166   c . Plug connector body  150  and plug backshell  154  are then threadably engaged using plug thread  164  and backshell thread  184 . Epoxy potting  141  is then injected into plug backshell  154  such that no voids are present, which could allow liquid/moisture to bridge between the wires  104   a ,  104   b ,  104   c . As it cures, epoxy potting  141  adheres to second cable  104  and plug connector body  150 . Epoxy potting  141  eliminates any leak path between the wires ( 104   a ,  104   b ,  104   c ) and socket contacts ( 168   a ,  168   b ,  168   c ) on the backside of plug connector body  150 . Epoxy potting  141  also aids in increasing the tensile pull strength of the connector assembly  100 . 
     After receptacle connector member  105  and plug connector member  106  are assembled, connector assembly  100  is assembled so a to facilitate electrical communication between first cable  102  and second cable  104 . Second radial seal  108  is positioned within outer wall groove  118  while first radial seal  107  is positioned within outer wall groove  161 . Receptacle connector member  105  and plug connector member  106  are approximated and aligned such that keyed projections  129  and keyed grooves  165  are in alignment. Preferably, keyed projections  129  and keyed grooves  165  are arranged so as to allow only a single possible orientation for connecting receptacle connector member  105  with plug connector member  106 . Through the design and use of a single keying orientation, only a correctly aligned connection is possible, thus preventing the possibility of an unsuccessful or imperfect assembly of receptacle connector member  105  and plug connector member  106 . Receptacle connector member  105  and plug connector member  106  are slidingly engaged such that keyed projections  129  engage the keyed grooves  165  prior to pin contacts  136   a ,  136   b ,  136   c  engaging their respective socket contact  168   a ,  168   b ,  168   c . By aligning the keying features prior to the engagement of the contacts, the possibility of contact damage during alignment of the keying features is eliminated. Plug connector member  106  is inserted within receptacle connector member  105  such that plug flange  162  and inner wall flange  128  are in contact. The insertion of plug connector member  106  into receptacle connector member  105  causes radial compression of first radial seal  107  creating a watertight seal between plug connector member  106  and receptacle connector member  105 . 
     Next, coupling nut  152  is directed toward receptacle connector member  105  such that inner nut thread  174  threadably engages outer wall thread  119  . . . Coupling nut  152  is rotatably advanced to complete the mating of receptacle connector member  105  and plug connector member  106 . As coupling nut  152  is rotatably advanced, second radial seal  108  is radially compressed creating a seal between coupling nut  152  and receptacle connector body  110 . By rotating coupling nut  152  to radially compress second radial seal  108 , the force required to compress both first radial seal  107  and second radial seal  108  is converted to a torque which is less than the axial force requirement if coupling nut  152  was merely pushed toward receptacle connector member  105 . When compressed as described, second radial seal  108  prevents dirt and other miscellaneous debris from penetrating the connector assembly  100  such that operation of coupling nut  152  is not hindered following extended periods of field installation. Turning coupling nut  152  causes nut throughbore  179  to align with receptacle locking throughbore  122 . The alignment of nut throughbore  179  with receptacle locking throughbore  122  provides a visual check to ensure that receptacle connector member  105  and plug connector member  106  are fully engaged. A security seal member  190 , as shown in  FIG. 6 , is inserted through nut throughbore  179  and receptacle locking throughbore  122  to prevent tampering with installed connector assembly  100 . While assembly of connector assembly  100  has been described, connector assembly  100  can be similarly disassembled by merely removing security seal member  190 , rotatably uncoupling coupling nut  152  and pulling receptacle connector member  105  and plug connector member  106  apart if maintenance is necessary. This allows coupling nut  152 , receptacle connector member  105  and plug connector member  106  to be reused without requiring a swap out of first cable  102  and second cable  104 . 
     When fully assembled, connector assembly  100  of the invention includes a variety of sealing mechanisms to substantially eliminate the possibility of water/moisture intrusion as well as dirt and debris penetration. First radial seal  107  and second radial seal  108  provide dual radial seals with first radial seal  107  substantially eliminating any water leak potential at the contact interface while second radial seal  108  substantially prevents dirt and debris infiltration that could interfere with the operation of coupling nut  152 . In addition, potting  141  within receptacle connector member  105  and plug connector member  106  provides a moisture impervious barrier to substantially eliminate water wicking up first cable  102  and second cable  104 . Potting  141  serves a secondary purpose of substantially retaining the majority of the pull strength of first cable  102  and second cable  104  when connector assembly  100  is fully assembled. 
     Referring now to  FIGS. 7 ,  8  and  9 , there is illustrated one representative example application of connector assembly  100  of the invention. Connector assembly  100  depicted in this embodiment as connecting a water meter  200  with a transmitter  202  such as, for example, a radio frequency transmitter. As further depicted in  FIGS. 8 and 9 , water meter  200  can be located in a below ground water pit  204 . Connector assembly  100  provides a dual radial seal to prevent moisture/water intrusion as well as dirt and debris infiltration that can cause other prior art connectors to fail. Transmitter  202  can be shipped from the factory with receptacle connector member  105  while water meter  200  can be installed with plug connector member  106 . Connector assembly  100  allows for easy field installation as no special tools, strength, skills or dexterity are necessary to connect receptacle connector member  105  with plug connector member  106 . 
     As shown in a related embodiment in  FIG. 10 , receptacle connector member  105  can include a receptacle cover  210  to protect receptacle connector member  105  prior to installation while plug connector member  106  can include a plug cover  212  as shown in  FIG. 11 , to similarly protect plug connector member  106 . The use of receptacle cover  210  and plug cover  212  allow both receptacle connector member  105  and plug connector member  106  to have an effective life of twenty years in one example embodiment. For example, receptacle connector member  105  and plug connector member  106  can be effectively stored prior to use for 15 years using receptacle cover  210  and plug cover  212  followed by the successful mating of receptacle connector member  105  and plug connector member  106  for another five years. 
     Although various embodiments of the invention have been disclosed here for purposes of illustration, it should be understood that a variety of changes, modifications and substitutions may be incorporated without departing from either the spirit or scope of the invention.