Patent Publication Number: US-9419370-B1

Title: Sealed electrical connector assembly

Description:
This application is a continuation of U.S. non-provisional application Ser. No. 14/735,996 entitled “Sealed electrical connector assembly” filed Jun. 10, 2015 in the names of Keep et al, which is a continuation-in-part of U.S. non-provisional application Ser. No. 14/685,580 entitled “Sealed electrical connector assembly” filed Apr. 13, 2015 in the names of Taylor et al (hereinafter referred to as the &#39;580 application); both of said applications are incorporated by reference as if fully set forth herein. 
    
    
     FIELD OF THE INVENTION 
     The field of the present invention relates to electrical connector assemblies. In particular, a sealed electrical connector assembly including a radially compressed wire grommet is disclosed herein. 
     BACKGROUND 
     In certain circumstances it is desirable to isolate from a use environment the electrical contacts and wires within an electrical connector assembly. One such circumstance arises when electrical connectors are employed in aviation. Exposure to extremes of temperature, pressure, or humidity, and frequent cycling between those extremes (e.g., with each takeoff, climb, cruise, descent, and landing) can lead to corrosion or other degradation of the electrically conductive parts of the connector. In certain conventional electrical connector assemblies a resiliently deformable wire grommet is employed to seal around one or more wires that enter the connector assembly. It may be desirable to provide improved or enhanced sealing around the wires by a wire grommet. 
     An example of a conventional connector assembly (arranged according to an SAE AS50151 standard in the example shown) is shown in  FIGS. 12-18  and comprises a substantially rigid front connector body  30 ; a substantially rigid rear connector body  20 ; a resiliently deformable wire grommet  10 ; and a threaded nut  40 . The rear connector body  20  (also referred to as a connector accessory or as a connector backshell) has a rear axial passage  22  therethrough; the front connector body  30  (also referred to as a plug connector body in a plug-type connector assembly, or as a receptacle connector body in a receptacle-type connector assembly) has a front axial passage. When the connector assembly is connected to one or more wires  90  (three wires  90  in the examples shown, with spaces for more; any suitable number of one or more wires can be employed) and assembled, a resiliently deformable wire grommet  10  is positioned within the front axial passage and the wires  90  pass through the rear axial passage  22  and through corresponding wire passages  12  of the grommet  10 . An insulating body  38  of the front connector body  30  is structurally arranged so as to hold one or more electrical contacts  92  that are each connected to a corresponding wire  90 . In the examples shown the electrical contacts  92  are pin contacts; in other examples the contacts are socket contacts. The wire grommet  10  serves to isolate the electrical contacts  92  and the conductive cores of the wires  90  from a use environment. 
     The front connector body  30  of the conventional connector assembly has triangular teeth  39  arranged just outside the rear end of the front axial passage; the rear connector body  20  of the conventional connector assembly has mating triangular teeth  29  arranged around the front end of the rear axial passage  22 . The rear connector body  20  of the conventional connecter assembly also can have a so-called web  29   w  between the teeth  29  but not extending beyond the tips of the teeth  29 . The teeth  29  and  39  engage one another when the front connector body  30  and the rear connector body are assembled, but no portion of the teeth  29 , the web  29   w , or the connector body  29  extends forward into the interior of the front connector body  30  (i.e., forward beyond base portions of the teeth  39 ). 
     The nut  40  includes a central opening and internal threads  44 . The nut  40  is structurally arranged so as to receive through the central opening a rearward portion of the rear connector body  20  and to obstruct rearward movement of the forward portion of the rear connector body  20  through the central opening. In the example embodiment shown, an outward circumferential flange  28  of the rear connector body  20  is too large to pass an inward circumferential flange  46  of the nut  40 . A rearward portion of the front connector body  30  includes external threads  34  that engage the internal threads  44  of the nut  40 . Tightening of the nut  40  threadedly engaged on the rearward portion of the front connector body  30  (via threads  34 / 44 ) results in forward movement of the nut  40  and the rear connector body  20  toward the front connector body  30 ; fully tightening the nut  40  results in fully engaged assembly of the connector bodies  30  and  20  and engagement of the teeth  29  and  39 . 
     The wire grommet  10  has a substantially cylindrical outer surface and one or more axial wire passages  12  therethrough. Each wire passage  12  includes two or more wire-sealing segments  12   a  (also referred to as glands) and an intervening, transversely enlarged, internal chamber  12   b  between each adjacent pair of wire-sealing segments  12   a  along each wire passage  12 . Each wire-sealing segment  12   a  is sized and shaped so as to (i) enable a corresponding wire  90  to be inserted through the corresponding wire passage  12  and (ii) form a seal around the corresponding inserted wire  90 . A rear portion of the wire grommet  10  extends rearward beyond the rear end of the front connector body  30  and is received within a rearward-tapered forward segment  24  of the rear axial passage  22 . The nut  40  is tightened and the front and rear connector bodies  30  and  20  are fully engaged (by engagement of the teeth  39  and  29 ), the tapered segment  24  radially compresses the protruding rearward portion of the wire grommet  10  and only the hindmost wire-sealing segment  12   a  of each passage  12 . 
     The introduction of lighter-weight wires with spiral tape insulation has been beneficial for overall weight reduction in avionics applications. However, those wires tend to have an oval or elliptical cross section and an uneven outer insulator surface where adjacent tape windings overlap, resulting in inadequate sealing of the wires by conventional connector assemblies. Inadequately sealed connectors are subject to more rapid corrosion, resulting in premature connector degradation or failure and requiring more frequent repair or replacement. It would be desirable to provide a connector assembly that provides improved sealing, particularly around wires with non-circular cross sections or uneven outer insulator surfaces. 
     SUMMARY 
     An inventive connector assembly comprises a substantially rigid front connector body, a substantially rigid rear connector body, a resiliently deformable wire grommet, and a threaded nut. The resiliently deformable wire grommet has a substantially cylindrical outer surface and one or more axial wire passages therethrough. Each wire passage includes two or more wire-sealing segments; each wire-sealing segment is sized and shaped so as to (i) enable a corresponding wire to be inserted through the corresponding wire passage and (ii) form a seal around the corresponding inserted wire. The front connector body has a front axial passage. A rearward portion of the front connector body includes external threads. A forward portion of the front connector body is structurally arranged so as to hold one or more electrical contacts that are each connected to a corresponding wire passing through the rear axial passage and the corresponding wire passage of the grommet. At least portions, including a rearward portion, of the front axial passage are structurally arranged so as to receive therein the grommet without substantial radial compression of the grommet. 
     The rear connector body has a rear axial passage therethrough. A front end of the rear axial passage is large enough to receive therein a rearward portion of the grommet without substantial radial compression of the grommet. A rearward-tapered segment of the rear axial passage is structurally arranged so as to receive therein the rearward portion of the grommet, engage the outer surface of the rearward portion of the grommet, and compress radially the rearward portion of the grommet and one or more of the wire-sealing segments of each wire passage therein. A forward portion of the rear connector body, including at least a portion of the tapered segment of the rear axial passage, is structurally arranged to extend into and fit within the rearward portion of the front axial passage, interposed between the rearward portion of the grommet and an inner surface of the rearward portion of the front axial passage. 
     The nut has a central opening and internal threads. The nut is structurally arranged so as to (i) receive through the central opening a rearward portion of the rear connector body, (ii) obstruct rearward movement of the forward portion of the rear connector body through the central opening, and (iii) engage with the internal threads the external threads of the front connector body. The forward portion of the rear connector body and the rearward portion of the front connector body are structurally adapted so as to effect non-rotatable engagement of the front and rear connector bodies. The connector assembly is structurally arranged so that tightening of the nut threadedly engaged on the rearward portion of the front connector body results in forward movement of the nut and the rear connector body toward the front connector body, forward movement of the forward portion of the rear connector body into the rearward portion of the front axial passage, rearward movement of the rearward portion of the grommet into the tapered segment of the rear axial passage, and radial compression, by the tapered segment of the rear axial passage, of the rearward portion of the grommet and one or more of the wire-sealing segments of each wire passage therein. 
     A method employing the inventive connector assembly comprises: (a) inserting each one of a set of one or more wires through the wire grommet through a corresponding one of the one or more wire passages; (b) securing one or more corresponding electrical contacts, connected to the forward ends of the wires, to be held by the forward portion of the front connector body; (c) inserting the grommet into the front axial passage; (d) engaging the front and rear connector bodies; (e) threadedly engaging the nut and the front connector body; and (f) tightening of the nut threadedly engaged on the rearward portion of the front connector body, thereby resulting in forward movement of the nut and the rear connector body toward the front connector body, forward movement of the forward portion of the rear connector body into the rearward portion of the front axial passage, rearward movement of the rearward portion of the grommet into the tapered segment of the rear axial passage, and radial compression, by the tapered segment of the rear axial passage, of the rearward portion of the grommet and one or more of the wire-sealing segments of each wire passage therein. 
     Objects and advantages pertaining to sealed electrical connector assemblies may become apparent upon referring to the example embodiments illustrated in the drawings and disclosed in the following written description or appended claims. 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of an example of an inventive sealed electrical connector assembly with wires in a fully assembled arrangement. 
         FIG. 2  is an isometric view of front and rear connector bodies of the example inventive connector assembly. 
         FIG. 3  is an isometric view of a longitudinal cross section of the front and rear connector bodies of the example inventive connector assembly. 
         FIGS. 4 and 5  are isometric and side views, respectively, of a longitudinal cross section of the example inventive connector assembly with wires and contacts in a partly assembled arrangement. 
         FIGS. 6 and 7  are isometric and side views, respectively, of a longitudinal cross section of the example inventive connector assembly with wires and contacts in a fully assembled arrangement. 
         FIGS. 8A, 8B, and 8C  are side cross-sectional, isometric cross-sectional, and isometric views of a front connector body of the example inventive connector assembly. 
         FIGS. 9A, 9B, and 9C  are side cross-sectional, isometric cross-sectional, and isometric views of a rear connector body of the example inventive connector assembly. 
         FIGS. 10A and 10B  are side cross-sectional and rear views of a wire grommet of the example inventive connector assembly. 
         FIGS. 11A and 11B  are side cross-sectional and isometric views of a nut of the example inventive connector assembly. 
         FIG. 12  is an isometric view of an example of a conventional sealed electrical connector assembly with wires in a fully assembled arrangement. 
         FIG. 13  is an isometric view of front and rear connector bodies of the example conventional connector assembly. 
         FIG. 14  is an isometric view of a longitudinal cross section of the front and rear connector bodies of the example conventional connector assembly. 
         FIGS. 15 and 16  are isometric and side views, respectively, of a longitudinal cross section of the example conventional connector assembly with wires and contacts in a partly assembled arrangement. 
         FIGS. 17 and 18  are isometric and side views, respectively, of a longitudinal cross section of the example conventional connector assembly with wires and contacts in a fully assembled arrangement. 
     
    
    
     The embodiments depicted are shown only schematically: all features may not be shown in full detail or in proper proportion, certain features or structures may be exaggerated relative to others for clarity, and the drawings should not be regarded as being to scale. In  FIGS. 3-7, 8B, 9B, and 14-18 , cross hatching has been omitted to reduce clutter in the drawings. The embodiments shown are only examples: they should not be construed as limiting the scope of the present disclosure or appended claims. 
     DETAILED DESCRIPTION OF EMBODIMENTS 
     An example of an inventive connector assembly is shown in  FIGS. 1-7  and comprises a substantially rigid front connector body  300  ( FIGS. 8A-8C ); a substantially rigid rear connector body  200  ( FIGS. 9A-9C ); a resiliently deformable wire grommet  100  ( FIGS. 10A and 10B ); and a threaded nut  400  ( FIGS. 11A and 11B ). The front connector body  300 , the rear connector body  200 , and the nut  400  can each comprise any one or more suitably rigid solid materials, including but not limited to: one or more metals or metal alloys; one or more plastics, resins, or polymers; one or more natural or synthetic fibrous materials; one or more other electrically conductive materials; or one or more other electrically insulating materials. 
     For purposes of the present disclosure and appended claims, directional terms such a front, forward, rear, rearward, and so forth are defined relative to the connector assembly, with “front” and the like being the direction from the connector assembly toward a mating connector assembly, and “rear” and the like being the opposite direction, i.e., toward one or more wires or a cable connected to the connector assembly. Any motion or movement recited in the disclosure, examples, or claims are relative motions or movements, e.g., forward movement of the rear connector body  200  toward the front connector body  300  is equivalent to rearward movement of the front connector body  300  toward the rear connector body  200 . 
     The substantially rigid rear connector body  200  (also referred to as a connector accessory or as a connector backshell) has a rear axial passage  202  therethrough; the substantially rigid front connector body  300  (also referred to as a plug connector body in a plug-type connector assembly, or as a receptacle connector body in a receptacle-type connector assembly) has a front axial passage  302 . In the example shown, the front connector body  300  is arranged in compliance with a MIL-DTL-38999 standard; any other suitable arrangement of the front connector body  300  can be employed, e.g., a front connector body arranged in compliance with an SAE AS50151 standard. While the inventive apparatus and methods disclosed or claimed herein can be implemented in a variety of connector types or arrangements, those inventive apparatus and methods may be particularly applicable when implemented with front connector bodies compliant with a MIL-DTL-38999 specification or an SAE AS50151 standard. The current versions of those specifications and standards (i.e., MIL-DTL-38999M dated 11 Feb. 2015 and SAE AS50151B dated 28 May 2013) are incorporated by reference as if fully set forth herein. When the connector assembly is connected to one or more wires  90  (six wires  90  in the examples shown; any suitable number of one or more wires can be employed) and assembled, a resiliently deformable wire grommet  100  is positioned within the front axial passage  302  and the wires  90  pass through the rear axial passage  202  and through corresponding wire passages  102  of the grommet  100 . A forward portion of the front connector body  300  is structurally arranged so as to hold one or more electrical contacts  92  that are each connected to a corresponding wire  90 . In the examples shown the electrical contacts  92  are pin contacts; in other examples the contacts are socket contacts. Any suitable number (one through 128 or more), type (e.g., pin or socket), or arrangement (e.g., square, rectangular, polygonal, or circular array or arrangement) of the one or more electrical contacts  92  can be employed in any type of connector assembly (e.g., plug, receptacle, bulkhead-mounted, wall-mounted, or cable-mounted). The wire grommet  100  serves to isolate the electrical contacts  92  and the conductive cores of the wires  90  from a use environment. 
     Any suitably rigid material can be employed for the front connector body  300  and the rear connector body  200 , as noted above. In many example embodiments, the rear connector body  200  comprises a metal or metal alloy, so that the rear connector body  200  is electrically conducting and can serve to at least partly electromagnetically shield the one or more wires  90  passing through the rear axial passage  202 . If the wires  90  are contained within a sheath (not shown) rearward of the connector assembly, that sheath can continue around a rearward portion of the rear connector body, if needed or desired. In some examples such a sheath can include conductive sheathing that serves as electromagnetic shielding for the wires  90 , and electrical continuity can be established between such conductive sheathing and a conductive rear connector body  200  (e.g., by banding or crimping the conductive sheath onto the rear connector body  200 ). In some examples the sheath can include an outer insulating layer that continues around a rearward portion of the rear connector body  200  (e.g., plastic or elastomeric shrink tubing applied around the wires  90  and the rear connector body  200 ). 
     In many example embodiments, the front connector body  300  includes one or more metals or metal alloys, which can serve as electrical shielding in a manner similar to that described for the rear connector body  200 , particularly if both front and rear connector bodies  300  and  200  include one or more metals or metal alloys and are in electrical contact with one another. The front connector body typically also includes one or more insulating materials arranged for holding the electrical contacts  92  in place without introducing unwanted electrical contact between them (i.e., without shorting them). In the example embodiment shown, the front connector body  300  includes an insulating body  308  (comprising, e.g., thermoplastic or other suitable insulating material) with wire channels  310  therethrough. Each wire channel  310  accommodates a corresponding one of the wires  90  and has a corresponding one of the electrical contacts  92  held at its front end. Additional structural members  312  can be employed to hold the electrical contacts  92  in place if needed or desired. A front end of the front connector body  300  can be structurally adapted in any suitable way to engage a mating connector assembly. In the example embodiment shown, the front connector body  300  includes mating hardware  314  for engaging a corresponding portion of a mating connector (not shown). 
     When the front and rear connector bodies  300  and  200  are assembled, a forward portion  207  of the front connector body  200  is received in a rearward portion of the interior of the front axial passage  302 . In the example shown, the forward portion  207  extends forward beyond the tips of the teeth  209  so as to extend forward beyond the base portions of the teeth  309  when the front and rear connector bodies  300  and  200  are assembled with their respective teeth  309  and  209  engaged. In the example shown, engagement of the teeth  209  and  309  (triangular in this example; other suitable shapes can be employed) effects non-rotatable engagement of the front and rear connector bodies  300  and  200 . In some other examples (e.g., as in the &#39;580 application), the outer surface of the forward portion of the rear connector body  200  can include a set of one or more longitudinal splines, keys, or grooves, the inner surface of the rearward portion of the front axial passage  302  can include a set of one or more longitudinal splines, keys, or grooves, and engagement of the splines, keys, or grooves of the front and rear connector bodies  300  and  200  effects the non-rotatable engagement. Non-rotatable engagement prevents twisting of the wire grommet  100  or wires  90  by relative rotation of the connector bodies  300  and  200  (e.g., induced by tightening the threaded nut  400 ; discussed further below). The term “non-rotatable” as used herein shall include arrangements wherein only limited or constrained relative rotation, or no rotation, of the front and rear connector bodies  300  and  200  might occur. For example, initial engagement of the triangular teeth  209  and  309  still permits limited relative rotation, but it is not until the teeth are fully engaged (i.e., “bottomed out”) that relative rotation is substantially prevented. Both initial and full engagement of the teeth  209  and  309  are encompassed by the term “non-rotatable engagement.” 
     The nut  400  includes a central opening  402  and internal threads  404 . The nut  400  is structurally arranged so as to receive through the central opening  402  a rearward portion of the rear connector body  200  and to obstruct rearward movement of the forward portion of the rear connector body  200  through the central opening  402 . In the example embodiment shown, an outward circumferential flange  208  of the rear connector body  200  is too large to pass an inward circumferential flange  406  of the nut  400 ; other suitable structural arrangements can be employed. A rearward portion of the front connector body  300  includes external threads  304  that engage the internal threads  404  of the nut  400 . Tightening of the nut  400  threadedly engaged on the rearward portion of the front connector body  300  (via threads  304 / 404 ) results in forward movement of the nut  400  and the rear connector body  200  toward the front connector body  300  and concomitant forward movement of the forward portion  207  of the rear connector body  200  into the rearward portion of the front axial passage  302 . Fully tightening the nut  400  results in fully engaged assembly of the connector bodies  300  and  200  at the forward limit of forward movement of the rear connector body  200  and the nut  400  (e.g., with the teeth  209  and  309  engaged in the example shown). In some examples (e.g., in the example shown in the &#39;580 application), contact between the flange  208  of the rear connector body  200  and a rear end of the front connector body  300  limits the forward movement. 
     The resiliently deformable (i.e., elastically deformable) wire grommet  100  has a substantially cylindrical outer surface and one or more axial wire passages  102  therethrough. Each wire passage  102  includes two or more wire-sealing segments  102   a  (also referred to as glands). Each wire passage  102  typically also includes an intervening, transversely enlarged, internal chamber  102   b  between each adjacent pair of wire-sealing segments  102   a  along each wire passage  102 ; such enlarged chambers  102   b  can facilitate insertion of the wires  90  through the corresponding passages  102  (e.g., by providing space to accommodate displacement of compressed grommet material from adjacent wire-sealing segments  102   a ) without unduly compromising the sealing of each wire  90  by the corresponding passage  102 . Each wire-sealing segment  102   a  is sized and shaped so as to (i) enable a corresponding wire  90  to be inserted through the corresponding wire passage  102  and (ii) form a seal around the corresponding inserted wire  90 . Typically this is achieved by making the wire-sealing segments  102   a  slightly smaller than the thickness of the wire  90 . Resilient stretching of each wire-sealing segment  102   a  enables the slightly over-sized wire  90  (and in some examples a wire-containing tube of an insertion/removal tool) to be inserted through the passage  102 ; resilient rebound of each wire-sealing segment  102   a  creates seal around the corresponding wire  90 . Exactly how much smaller than the wire thickness are the wire-sealing segments can vary and typically is determined by the properties of the resilient grommet material, the surface characteristics of the wire insulation, the cross-sectional shapes of the wires  90  and the wire-sealing segments  102   a  (see below), the size of a wire-containing tube of an insertion/removal tool (if employed), the amount of radial compression of the wire grommet by the rear connector body (discussed further below), and the tightness of the seal needed or desired in a given use environment (i.e., to achieve operationally acceptable sealing). Any suitable size differential can be employed that enables insertion of the wires  90  through the wire passages  102  and also results in an operationally acceptable seal around the wires  90 . 
     Typical resiliently deformable materials for wire grommet  100  include, but are not limited to: synthetic or natural rubber; silicone or fluorosilicone elastomer; fluorocarbon elastomer (e.g., Viton®); ethylene propylene diene monomer (EPDM) elastomer; neoprene; other resiliently deformable polymer or resin; or other suitable resiliently deformable material. In some example embodiments the grommet  100  or the front axial passage  302  can further include a rotational indexing structure (e.g., one or more mating longitudinal grooves, keys, or splines) arranged to permit insertion of the grommet  100  into the front axial passage  302  in only one relative orientation about a longitudinal axis. In some other examples, the wires  90  passing through the passages  102  and corresponding passages through the insulating body  308  effects rotational alignment of the wire grommet  100  within the front axial passage  302  of the front connector body  300 . In some examples, the grommet  100  can be attached or secured to the front connector body  300  within the front axial passage  302 , e.g., by adhesive or a mechanical retaining member such as a snap ring or threaded retaining ring. In other examples, the grommet  100  is not secured or attached to the front connector body  300 , but is held in place by the engagement of the front and rear connector bodies  300  and  200  with each other. 
     Any suitable cross-sectional shape can be employed for the wire-sealing segments  102   a . In some example embodiments each wire-sealing segment  102   a  has a substantially circular cross section to accommodate a corresponding wire also having a circular cross section. A circular cross section for the wire-sealing segments  102   a  can be employed in some example embodiments with non-circular wires  90  (e.g., oval or elliptical cross sections), so as to eliminate the need to rotationally orient the non-circular wire  90  before inserting it into the corresponding wire passage  102 . In still other example embodiments, non-circular wire-sealing segments  102   a  can be employed having a shape corresponding to a non-circular shape of the wires  90 , with the wires  90  being properly oriented before insertion through the wire passages  102 . 
     In many common instances, resiliency of the grommet  100  and the size or shape differential between the wire-sealing segments  102   a  and the wires  90  may not result in a sufficiently good seal around the wires  90 . Such instances can arise more frequently when non-circular wires  90  are employed with a grommet  100  having substantially circular wire-sealing segments  102   a  of the wire passages  102 . Oval or elliptical wire cross sections arising from current wire manufacturing processes are increasingly common. Poor sealing can also arise with wires have insulation in the form of a spiral-wound tape, which results in a spiral ridge on the outer surface of the wire where each turn of the insulating tape overlaps an adjacent turn. That ridge can provide a path for moisture or other contaminants to enter the connector. It therefore would be desirable to provide enhanced sealing of the wires  90  by the grommet  100 . 
     In the inventive connector assemblies disclosed herein, the rear connector body  200  is structurally adapted so as to provide, upon fully engaged assembly of the connector assembly, radial compression, within the interior of the front axial passage  302  of the front connector body  300 , of the wire grommet  100  over a portion of its length, including radial compression of one or more of the wire-sealing segments  102   a . The front connector body  300  can also be so adapted in some instances, but in many instances the front connector body  300  is of a conventional arrangement (e.g., arranged in compliance with a MIL-DTL-38999 specification or an SAE AS50151 standard), with the inventive features of the connector assembly residing primarily in the arrangement of the rear connector body  200 . Both connector bodies  200  and  300  can be provided by the same manufacturer or by different manufacturers; in the latter instances (i.e., a conventional front connector body  300  paired with an inventive rear connector body  200 ) the front and rear connector bodies  300  and  200  may often be provided by different manufacturers. In the example of the &#39;580 application, both the front and rear connector bodies  300  and  200  are structurally adapted so as to provide, upon fully engaged assembly of the connector assembly, radial compression of the wire grommet  100  over a portion of its length that includes two or more of the wire-sealing segments  102   a  of each wire passage  102 . In both the present application and the &#39;580 application, it is the radial compression, particularly of at least one wire-sealing segments  102   a  (present application), or two or more wire-sealing segments  102   a  (&#39;580 application), of the of each wire passage  102 , that provides the desired enhanced sealing of the wires  90  by the grommet  100 , even when non-circular wires  90  and circular wire-sealing segments  102   a  are employed, or even when wires  90  having spiral-wound insulation are employed. 
     To achieve the inventive arrangement, the front end of the rear axial passage  202  is large enough to receive therein a rearward portion of the grommet  100  without substantial radial compression of the grommet  100 , and the rear axial passage  202  includes a rearward-tapered segment  204  (referred to hereafter as the tapered segment  204 ). The tapered segment  204  of the rear axial passage  202  is structurally arranged so as to receive therein the rearward portion of the grommet  100 , engage its outer surface, and compress it radially along with radially compressing one or more of the wire-sealing segments  102   a  of each wire passage  102  within the grommet  100 . At least portions, including a rearward portion, of the front axial passage  302  are structurally arranged so as to receive therein at least the forward portion of the grommet  100  without substantial radial compression of the grommet  100 . In the inventive connector assemblies disclosed or claimed herein, the forward portion  207  of the rear connector body  200 , including at least a portion of the tapered segment  204  of the rear axial passage  202 , is structurally arranged to extend into and fit within the rearward portion of the front axial passage  302 , interposed between the rearward portion of the grommet  100  and an inner surface of the rearward portion of the front axial passage  302 . 
     An inventive connector assembly arranged according to the present disclosure or appended claims is thus structurally arranged so that tightening the nut  400  drives forward portion  207  and the tapered segment  204  of the axial passage  202  forward into the rearward portion of the front axial passage  302  wedged between the inner surface of the front axial passage  302  and the outer surface of the grommet  100 . The wedge action of the tapered segment  204  on the outer surface of the grommet  100  results in radial compression of the rearward portion of the grommet  100  and one or more of the wire-sealing segments  102   a  of each wire passage  102  therein. In some examples (e.g., the example shown in the &#39;580 application), two or three or more wire-sealing segments can be radially compressed by the wedge action, on the outer surface of the grommet  100 , of the tapered segment  204  of the rear axial passage  202 . The non-rotatable engagement of the front and rear connector bodies  300  and  200  (e.g., by engagement of the teeth  209  and  309 ) reduces or prevents torsional strain or twisting of the wire grommet  100  by the engaged tapered segment  204  as the rear connector body  200  is driven forward by tightening the nut  400 . Such twisting or torsional strain can result in various undesirable effects, such as excessive resistance to tightening the nut  400 , disruption of the sealing of the wire-sealing segments  102   a  around the wires  90 , twisting or breakage of the wires  90 , or structural failure of the wire grommet  100 . 
     The grommet  100  comprises a resiliently deformable material to enable radial compression by the tapered segment  204  of the rear axial passage  202 . However, such resilient materials are not necessarily particularly compressible; radial compression of the rearward portion of the grommet  100  typically causes a portion of the grommet  100  forward of the compressed portion to bulge outward, i.e., to expand radially. In some examples, a forward portion of the tapered segment  204  of the rear axial passage  202  can be structurally arranged so as to accommodate that radial expansion, e.g., by having a radius at its forward end that is larger than the radius of the grommet  100  in its uncompressed state. In some examples, at the forward limit of the forward movement of the rear connector body  200  toward the front connector body  300 , a gap remains at a front end of the rear connector body  200  that can accommodate the radial expansion of that portion of the grommet  100  forward of the radially compressed rearward portion of the grommet  100 . In some of those latter examples, a resilient sealant  330  can partly fill the gap. 
     In some examples, the connector assembly further comprises a resilient O-ring (e.g., as in FIGS. 12-14 of the &#39;580 application). At the forward limit of the forward movement of the rear connector assembly  200 , engagement of the O-ring between the outer surface of the forward portion of the rear connector body  200  (e.g., just forward of the flange  208 ) and the inner surface of the rear portion of the front axial passage  302  serves to establish a seal to substantially isolate from the use environment the rear portion of the front axial passage  302 . The seal provided by the O-ring is in addition to that provided by the grommet  100  and its radial compression by the tapered segment  204  of the rear axial passage  202 . In examples that include splines, the splines typically are arranged or positioned so as not to interfere with sealing provided by the O-ring  340 . 
     An example method employing an inventive connector assembly, e.g., such as the example shown in  FIGS. 1-7 , comprises: (a) inserting each one of a set of one or more wires  90  through the wire grommet  100  through a corresponding one of the one or more wire passages  102 ; (b) securing one or more corresponding electrical contacts  92 , connected to the forward ends of the wires  90 , to be held by the forward portion of the front connector body  300 ; (c) inserting the grommet  100  into the front axial passage  302 ; (d) engaging the front and rear connector bodies  300  and  200 ; (e) threadedly engaging the nut  400  and the front connector body  300 ; (f) tightening of the nut  400  threadedly engaged on the rearward portion of the front connector body  300 , thereby resulting in forward movement of the nut  400  and the rear connector body  200  toward the front connector body  300 , forward movement of the non-rotatably engaged forward portion  207  of the rear connector body  200  into the rearward portion of the front axial passage  302 , rearward movement of the rearward portion of the grommet  100  into the tapered segment  204  of the rear axial passage  202 , and radial compression, by the tapered segment  204  of the rear axial passage  202 , of the rearward portion of the grommet  100  and one or more of the wire-sealing segments  102   a  of each wire passage  102  therein. Typically, but not necessarily, the contacts  92  are connected to the wires  90  before the wires  90  are inserted through the wire grommet  100 ; typically, but not necessarily, the contacts  92  are connected to the wires  90  before the contacts  92  are secured to be held by the front connector body  300 . 
     In some examples of such a method, the one or more wires  90  are inserted through the wire grommet  100  before inserting the wire grommet  100  into the front axial passage  302 . In those instances, the wires  90  serve to align the wire passages  102  with corresponding wire passages in the front connector body  300 . In other examples of such methods, the one or more wires  90  are inserted through the wire grommet  100  after inserting the wire grommet  100  into the front axial passage  302 . In those instances, an insertion/removal tool is used that comprises a tube arranged (i) to receive therein one of the one or more wires  90 , (ii) to be inserted along with the wire  90  through the corresponding one of the one or more wire passages  102 , and (iii) to be withdrawn from the corresponding wire passage  102  leaving the wire  90  within the corresponding wire passage  102 . 
     In addition to the preceding, the following examples fall within the scope of the present disclosure or appended claims: 
     Example 1 
     A connector assembly comprising: (a) a resiliently deformable wire grommet having a substantially cylindrical outer surface and one or more axial wire passages therethrough, wherein each wire passage includes two or more wire-sealing segments and each wire-sealing segment is sized and shaped so as to (i) enable a corresponding wire to be inserted through the corresponding wire passage and (ii) form a seal around the corresponding inserted wire; (b) a substantially rigid front connector body having a front axial passage, wherein (i) a rearward portion of the front connector body includes external threads; (ii) a forward portion of the front connector body is structurally arranged so as to hold one or more electrical contacts that are each connected to a corresponding wire passing through the rear axial passage and the corresponding wire passage of the grommet, and (iii) at least portions, including a rearward portion, of the front axial passage are structurally arranged so as to receive therein the grommet without substantial radial compression of the grommet; (c) a substantially rigid rear connector body having a rear axial passage therethrough, wherein (i) a front end of the rear axial passage is large enough to receive therein a rearward portion of the grommet without substantial radial compression of the grommet, (ii) a rearward-tapered segment of the rear axial passage is structurally arranged so as to receive therein the rearward portion of the grommet, engage the outer surface of the rearward portion of the grommet, and compress radially the rearward portion of the grommet and one or more of the wire-sealing segments of each wire passage, and (iii) a forward portion of the rear connector body, including at least a portion of the tapered segment of the rear axial passage, is structurally arranged to extend into and fit within the rearward portion of the front axial passage, interposed between the rearward portion of the grommet and an inner surface of the rearward portion of the front axial passage; and (d) a nut with a central opening and internal threads, wherein the nut is structurally arranged so as to (i) receive through the central opening a rearward portion of the rear connector body, (ii) obstruct rearward movement of the forward portion of the rear connector body through the central opening, and (iii) engage with the internal threads the external threads of the front connector body, wherein: (e) the forward portion of the rear connector body and the rearward portion of the front connector body are structurally adapted so as to effect non-rotatable engagement of the front and rear connector bodies; and (f) the connector assembly is structurally arranged so that tightening of the nut threadedly engaged on the rearward portion of the front connector body results in forward movement of the nut and the rear connector body toward the front connector body, forward movement of the forward portion of the rear connector body into the rearward portion of the front axial passage, rearward movement of the rearward portion of the grommet into the tapered segment of the rear axial passage, and radial compression, by the tapered segment of the rear axial passage, of the rearward portion of the grommet and one or more of the wire-sealing segments of each wire passage therein. 
     Example 2 
     The connector assembly of Example 1 wherein the front connector body is arranged in compliance with a MIL-DTL-38999 specification or an SAE AS50151 standard. 
     Example 3 
     The connector assembly of any one of Examples 1 or 2 wherein the grommet extends rearward beyond a rear end of the front connector body. 
     Example 4 
     The connector assembly of any one of Examples 1 or 2 wherein a rear end of the front connector body extends rearward beyond a rear end of the grommet. 
     Example 5 
     The connector assembly of any one of Examples 1 through 4 wherein: (i) the outer surface of the forward portion of the rear connector body includes a set of one or more longitudinal splines or grooves, (ii) the inner surface of the rearward portion of the front axial passage includes a set of one or more longitudinal splines or grooves, and (iii) engagement of the splines or grooves of the front and rear connector bodies effects the non-rotatable and longitudinally movable engagement thereof. 
     Example 6 
     The connector assembly of any one of Examples 1 through 4 wherein (i) the forward portion of the rear connector body includes a set of multiple forward-extending teeth, (ii) the rearward portion of the front connector body includes a set of multiple rearward-extending teeth, and (iii) engagement of the teeth of the front and rear connector bodies effects the non-rotatable engagement thereof. 
     Example 7 
     The connector assembly of any one of Examples 1 through 6 wherein each wire passage includes an intervening, transversely enlarged, internal chamber between each adjacent pair of wire-sealing segments along each wire passage. 
     Example 8 
     The connector assembly of any one of Examples 1 through 7 wherein (i) the tapered segment of the rear axial passage is structurally arranged so as to compress radially the rearward portion of the grommet and two or more of the wire-sealing segments of each wire passage and (ii) the connector assembly is structurally arranged so that tightening of the nut results in radial compression of two or more of the wire-sealing segments of each wire passage. 
     Example 9 
     The connector assembly of any one of Examples 1 through 8 wherein the grommet or the front axial passage includes a rotational indexing structure arranged to permit insertion of the grommet into the front axial passage in only one relative orientation about a longitudinal axis. 
     Example 10 
     The connector assembly of any one of Examples 1 through 9 wherein a forward portion of the tapered segment of the rear axial passage is structurally arranged so as to accommodate radial expansion of a portion of the grommet forward of the radially compressed rearward portion of the grommet. 
     Example 11 
     The connector assembly of any one of Examples 1 through 10 wherein the front and rear connector bodies are structurally arranged so that, at a forward limit of the forward movement, a gap remains at a front end of the rear connector body that can accommodate radial expansion of a portion of the grommet forward of the radially compressed rearward portion of the grommet. 
     Example 12 
     The connector assembly of Example 11 wherein a resilient sealant at least partly fills the gap. 
     Example 13 
     The connector assembly of any one of Examples 1 through 12 wherein (i) the rear connector body includes a radially outward-extending circumferential flange and (ii) contact between the flange and a rear end of the front connector body limits the forward movement. 
     Example 14 
     The connector assembly of any one of Examples 1 through 13 further comprising a resilient O-ring, wherein, at a forward limit of the forward movement, engagement of the O-ring between the outer surface of the forward portion of the rear connector body and the inner surface of the rear portion of the front axial passage serves to substantially isolate from a use environment the rear portion of the front axial passage. 
     Example 15 
     A method employing the connector assembly of any one of Examples 1 through 14, the method comprising: (a) inserting each one of a set of one or more wires through the wire grommet through a corresponding one of the one or more wire passages; (b) securing one or more corresponding electrical contacts, connected to the forward ends of the one or more wires, to be held by the forward portion of the front connector body; (c) inserting the grommet into the front axial passage; (d) engaging the front and rear connector bodies; (e) threadedly engaging the nut and the front connector body; and (f) tightening of the nut threadedly engaged on the rearward portion of the front connector body, thereby resulting in forward movement of the nut and the rear connector body toward the front connector body, forward movement of the forward portion of the rear connector body into the rearward portion of the front axial passage, rearward movement of the rearward portion of the grommet into the tapered segment of the rear axial passage, and radial compression, by the tapered segment of the rear axial passage, of the rearward portion of the grommet and one or more of the wire-sealing segments of each wire passage therein. 
     Example 16 
     The method of Example 15 wherein the one or more corresponding electrical contacts are connected to the one or more wires before the one or more wires are inserted through the wire grommet. 
     Example 17 
     The method of any one of Examples 15 or 16 wherein the one or more wires are inserted through the wire grommet before inserting the wire grommet into the front axial passage. 
     Example 18 
     The method of any one of Examples 15 or 16 wherein the one or more wires are inserted through the wire grommet after inserting the wire grommet into the front axial passage, using an insertion/removal tool that comprises a tube arranged (i) to receive therein one of the one or more wires, (ii) to be inserted along with the wire through the corresponding one of the one or more wire passages, and (iii) to be withdrawn from the corresponding wire passage leaving the wire within the corresponding wire passage. 
     Example 19 
     The method of any one of Examples 15 through 18 wherein each one of the one or more wires has a non-circular transverse cross section. 
     Example 20 
     The method of any one of Examples 15 through 19 wherein each one of the one or more wires has an oval or elliptical cross section. 
     Example 21 
     The method of any one of Examples 15 through 20 wherein each one of the one or more wires includes spiral-wrapped insulation. 
     Example 22 
     The method of any one of Examples 15 through 21 further comprising inserting into a sheath surrounding the set of one or more wires the rearward portion of the rear connector body. 
     Example 23 
     The method of Example 22 wherein the sheath includes electrically conductive sheathing arranged to serve as electromagnetic shielding for the set of one or more wires, the rear connector body comprises an electrically conductive material, and the electrically conductive sheathing is in electrical contact with the rear connector body. 
     Example 24 
     The method of Examples 22 or 23 wherein the sheath includes electrically insulating sheathing. 
     Example 25 
     An article comprising a substantially rigid backshell for an electrical connector assembly wherein: (a) the backshell has an axial passage therethrough; (b) a front end of the backshell axial passage is large enough to receive therein a rearward portion of a wire grommet without substantial radial compression of the grommet; (c) a rearward-tapered segment of the backshell axial passage is structurally arranged so as to receive therein the rearward portion of the grommet, engage the outer surface of the rearward portion of the grommet, and compress radially the rearward portion of the grommet and one or more wire-sealing segments of each one of one or more wire passages of the grommet; and (d) a forward portion of the backshell, including at least a portion of the tapered segment of the rear axial passage, is structurally arranged to extend into and fit within a rearward portion of an axial passage of a front connector body, with the grommet positioned within the front axial passage and with the forward portion of the backshell interposed between the rearward portion of the grommet and an inner surface of the rearward portion of the front axial passage. 
     Example 26 
     The article of Example 25 wherein the forward portion of the backshell, including at least a portion of the tapered segment of the rear axial passage, is structurally arranged to extend into and fit within a rearward portion of an axial passage of a front connector body that is arranged in compliance with a MIL-DTL-38999 specification or an SAE AS50151 standard, with the grommet positioned within the front axial passage and with the forward portion of the backshell interposed between the rearward portion of the grommet and an inner surface of the rearward portion of the front axial passage. 
     Example 27 
     The article of any one of Examples 25 or 26 wherein the tapered segment of the backshell axial passage is structurally arranged so as to compress radially the rearward portion of the grommet and two or more of the wire-sealing segments of each wire passage. 
     Example 28 
     The article of any one of Examples 25 through 27 wherein the forward portion of the backshell includes a set of multiple forward-extending teeth arranged to engage a set of multiple rearward-extending teeth of the front connector body and thereby effect substantially non-rotatable engagement of the backshell and the front connector body. 
     Example 29 
     The article of any one of Examples 25 through 27 wherein the outer surface of the forward portion of the backshell includes a set of one or more longitudinal splines or grooves arranged to engage a set of one or more longitudinal splines or grooves of the front connector body and thereby effect substantially non-rotatable engagement of the backshell and the front connector body. 
     Example 30 
     The article of any one of Examples 25 through 29 wherein a forward portion of the tapered segment of the backshell axial passage is structurally arranged so as to accommodate radial expansion of a portion of the grommet forward of the radially compressed rearward portion of the grommet. 
     Example 31 
     The article of any one of Examples 25 through 30 wherein the backshell is structurally arranged so that, at a forward limit of forward movement of the forward portion of the backshell into the front axial passage of the front connector body, a gap remains at a front end of the backshell that can accommodate radial expansion of a portion of the grommet forward of the radially compressed rearward portion of the grommet. 
     It is intended that equivalents of the disclosed example embodiments and methods shall fall within the scope of the present disclosure or appended claims. It is intended that the disclosed example embodiments and methods, and equivalents thereof, may be modified while remaining within the scope of the present disclosure or appended claims. 
     In the foregoing Detailed Description, various features may be grouped together in several example embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that any claimed embodiment requires more features than are expressly recited in the corresponding claim. Rather, as the preceding numbered examples and the appended claims reflect, inventive subject matter may lie in less than all features of a single disclosed example embodiment. Thus, the appended claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate disclosed embodiment. However, the present disclosure shall also be construed as implicitly disclosing any embodiment having any suitable set of one or more disclosed or claimed features (i.e., a set of features that are neither incompatible nor mutually exclusive) that appear in the present disclosure (including the numbered examples) or the appended claims, including those sets that may not be explicitly disclosed herein. In addition, for purposes of disclosure, each of the appended dependent claims shall be construed as if written in multiple dependent form and dependent upon all preceding claims with which it is not inconsistent. It should be further noted that the scope of the appended claims does not necessarily encompass the whole of the subject matter disclosed herein. 
     For purposes of the present disclosure and appended claims, the conjunction “or” is to be construed inclusively (e.g., “a dog or a cat” would be interpreted as “a dog, or a cat, or both”; e.g., “a dog, a cat, or a mouse” would be interpreted as “a dog, or a cat, or a mouse, or any two, or all three”), unless: (i) it is explicitly stated otherwise, e.g., by use of “either . . . or,” “only one of,” or similar language; or (ii) two or more of the listed alternatives are mutually exclusive within the particular context, in which case “or” would encompass only those combinations involving non-mutually-exclusive alternatives. For purposes of the present disclosure and appended claims, the words “comprising,” “including,” “having,” and variants thereof, wherever they appear, shall be construed as open ended terminology, with the same meaning as if the phrase “at least” were appended after each instance thereof, unless explicitly stated otherwise. 
     In the appended claims, if the provisions of 35 USC §112(f) are desired to be invoked in an apparatus claim, then the word “means” will appear in that apparatus claim. If those provisions are desired to be invoked in a method claim, the words “a step for” will appear in that method claim. Conversely, if the words “means” or “a step for” do not appear in a claim, then the provisions of 35 USC §112(f) are not intended to be invoked for that claim. 
     If any one or more disclosures are incorporated herein by reference and such incorporated disclosures conflict in part or whole with, or differ in scope from, the present disclosure, then to the extent of conflict, broader disclosure, or broader definition of terms, the present disclosure controls. If such incorporated disclosures conflict in part or whole with one another, then to the extent of conflict, the later-dated disclosure controls. 
     The Abstract is provided as required as an aid to those searching for specific subject matter within the patent literature. However, the Abstract is not intended to imply that any elements, features, or limitations recited therein are necessarily encompassed by any particular claim. The scope of subject matter encompassed by each claim shall be determined by the recitation of only that claim.