Abstract:
A connector assembly ( 10 ) is provided including a first connector ( 12 ) and a second connector ( 14 ) configured to mateably engage the first connector ( 12 ). The first connector ( 12 ) includes a housing ( 16 ), a conductor assembly ( 18 ) positioned within the housing and projecting from housing, and a resilient seal member ( 30 ) enclosing an interface between the housing ( 16 ) and the portion of the conductor assembly projecting from the housing. The second connector ( 14 ) includes an outer contact ( 60 ), an inner contact ( 62 ) nested within a portion of the outer contact ( 60 ), and a housing ( 64 ) containing the inner and outer contacts. Conductors of the conductor assembly ( 18 ) of the first connector ( 12 ) engage the outer ( 60 ) and inner ( 62 ) contacts of the second connector ( 14 ). Another resilient seal member ( 45 ) includes a flexible skirt ( 50 ) formed at an end portion thereof. The flexible skirt ( 50 ) forms a shroud covering a mating interface between a first conductor ( 20 ) of the first connector ( 12 ) and the inner contact ( 62 ) of the second connector ( 14 ) when the first and second connectors are mated. Design features incorporated into the second connector housing ( 64 ), inner contact ( 62 ), and outer contact ( 60 ) act to retard undesirable unmating of the connectors. The connector assembly ( 10 ) of the present invention may be used in applications requiring a dual wire or coaxial connector resistant to adverse environmental conditions, such as exposure to high-pressure gases or liquids, elevated temperatures, vibration, salt spray, etc.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of provisional application Ser. No. 60/648,224, filed on Jan. 28, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to electrical connectors and, more particularly, to electrical connectors designed for blind mating and for use in adverse environmental conditions.  
         [0003]     In some connector applications, blind mating of connectors (i.e., mating with no visual feedback provided to a user during mating) is necessary. Problems encountered with connectors under conditions of blind mating primarily involve centering and alignment of the connectors for proper mating of the electrical contacts without damage to the contacts. Additional mating problems, specific to each type of connector, may also arise. For example, in the blind mating of coaxial connectors, the center conductor of the coaxial cable should possess sufficient rigidity to resist the insertion forces encountered during mating without buckling.  
         [0004]     Problems caused by the need for blind mating capability may be compounded when the connector must be designed to operate in adverse environmental conditions, for example, in high-pressure environments and/or in environments with a risk of exposure to excess moisture or contaminants. In such cases, one or more seals must usually be provided to prevent or minimize exposure of the contact interface to the adverse conditions or contaminants. In addition, in some applications, engagement between mating contacts should be permanent to ensure proper functioning of the connector. Thus, the contact interface may be required to provide at least a specified minimum normal force to ensure proper operation of the connector and to inhibit undesired disengagement of the mated electrical contacts. Finally, it may be necessary to secure each contact within the connector housing or mounting structure in a manner sufficient to ensure that at least a minimum desired retention force (or pull-out force) is required to forcibly remove the contact from the housing.  
       SUMMARY OF THE INVENTION  
       [0005]     In accordance with the present invention, a connector assembly is provided including a first connector and a second connector configured to mateably engage the first connector. The first connector includes a housing, a conductor assembly positioned within the housing and projecting from housing, and a resilient seal member enclosing an interface between the housing and the portion of the conductor assembly projecting from the housing. The second connector includes an outer contact, an inner contact nested within a portion of the outer contact, and a housing containing the inner and outer contacts. Portions of the conductor assembly of the first connector engage the outer and inner contacts of the second connector. Another resilient seal member includes a flexible skirt formed at an end portion thereof. The flexible skirt forms a shroud covering a mating interface between a first conductor of the first connector and the inner contact of the second connector when the first and second connectors are mated. Design features incorporated into the second connector housing, inner contact, and outer contact act to impede undesirable unmating of the connectors. The connector assembly of the present invention may be used in applications requiring a dual wire or coaxial connector resistant to adverse environmental conditions, such as exposure to high-pressure gases or liquids, elevated temperatures, vibration, salt spray, etc. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]     In the drawings illustrating embodiments of the present invention:  
         [0007]      FIG. 1  is a cross-sectional side view of one embodiment of a mated connector assembly in accordance with the present invention;  
         [0008]      FIG. 2  is a partial cross-sectional side view of a mating end of one embodiment of a first connector in accordance with the present invention;  
         [0009]      FIG. 3  is a side view of a conductor assembly in accordance with the present invention;  
         [0010]      FIG. 4  is a cross-sectional view of the conductor assembly shown in  FIG. 3 ;  
         [0011]      FIG. 5  is a partial cross-sectional side view of a mating end of an alternative embodiment of a first connector in accordance with the present invention;  
         [0012]      FIG. 6  is a partial cross-sectional side view of an insulator plug in accordance with the present invention;  
         [0013]      FIG. 7  is a partial cross-sectional side view of a mating end of a second connector in accordance with the present invention;  
         [0014]      FIG. 8  is a perspective view of an outer contact incorporated into the second connector shown in  FIG. 7 ;  
         [0015]      FIG. 9  is a detail view of a portion of an inner contact incorporated into the second connector shown in  FIG. 7 ;  
         [0016]      FIG. 10  is a partial cross-sectional side view of the connector assembly of  FIG. 1 , showing a stage of assembly prior to the assembly stage shown in  FIG. 1 ; and  
         [0017]      FIG. 11  is a detail view of a portion of an outer contact incorporated into the second connector shown in  FIG. 7 . 
     
    
     DETAILED DESCRIPTION  
       [0018]      FIG. 1  shows a connector assembly  10  constructed in accordance with the present invention. Connector assembly  10  includes a first connector  12  and a second connector  14  configured to mateably engage first connector  12 .  
         [0019]     Referring to  FIG. 2 , first connector  12  includes a housing  16 , a conductor assembly  18  positioned within housing  16  and projecting from housing  16 , and a seal member  30  enclosing the interface between housing  16  and the portion of conductor assembly  18  projecting from the housing. Conductor assembly  18  projects through an orifice  16   a  formed in housing  16 . Housing  16  is shaped to provide surfaces for manipulation by a user or by an automated assembly device, for purposes of mating the first connector  12  with second connector  14 . Housing  16  is also shaped to provide surfaces that aid in locating and centering first connector  12  with respect to second connector  14  during mating of the connector assembly. In addition, housing  16  also aids in protecting conductor assembly  18  from damage. Housing  16  may be formed from any rigid polymer material resistant to hydrocarbon-based fluids, such as polyvinyl chloride (PVC) or glass-filled nylon. Housing  16  may be fabricated by known methods (for example, by molding) after which conductor assembly  18  is positioned and secured within housing  16  using known methods, for example adhesives or interference fits. Alternatively, housing  16  may be overmolded onto conductor assembly  18 .  
         [0020]     Referring to  FIGS. 3 and 4 , conductor assembly  18  includes a center conductor  20  and a center insulator or dielectric material  22  enclosing center conductor  20 . An end portion of center conductor  20  projects from a corresponding end portion of center dielectric  22 . An outer conductor  24  encloses center dielectric  22  and center conductor  20 , and an outer insulator or dielectric material  26  encloses outer conductor  24 . An end portion of outer conductor  24  projects from a corresponding end portion of outer dielectric  26 .  
         [0021]     In the embodiment shown in the drawings, center conductor  20  terminates in a tapered or rounded end portion  20   a  that aids in locating and centering center conductor  20  with respect to second connector  14  during mating of the connector assembly. Center conductor  20  is a substantially cylindrical solid conductor having a relatively rigid structure configured to resist buckling and lateral deformation during mating of the connector assembly. Center conductor  20  may be formed from a wire comprising a conductive metal or metal alloy, for example cartridge brass, beryllium copper, or copper covered steel. A centerline L extending along a centroidal axis of center conductor  20  defines a mating axis of first connector  12 .  
         [0022]     Center dielectric  22  separates center conductor  20  from outer conductor  24 . Also, as seen in  FIGS. 1 and 2 , an end portion of center dielectric  22  is recessed from an end portion of outer conductor  24  such that the center dielectric end portion abuts an insulator plug  45  (described below) positioned in an end portion of outer conductor  24 , within the recess. Center dielectric  22  may be formed from a polymer material having a dielectric constant within a desired predetermined range, depending on the connector application. Suitable materials for center dielectric  22  include various types of glass-filled nylon, polyethylene, polyurethane, and Teflon®.  
         [0023]     Outer conductor  24  aids in shielding center conductor  20  from spurious electromagnetic interference. Outer conductor  24  also aids in protecting center conductor  20  from physical damage. Outer conductor  24  includes an opening  24   a  which is beveled to ease insertion of an insulator plug  34  (described in greater detail below) therein during assembly of first connector  12 . Outer conductor  24  may be formed as a tube or sleeve from a conductive metal or metal alloy, for example cartridge brass, beryllium copper, or copper covered steel.  
         [0024]     Outer dielectric  26  aids in protecting conductors  20  and  24  from damage. Outer dielectric  26  may be overmolded or otherwise suitably applied to an outer surface of outer conductor  24 . Outer dielectric  26  may comprise a polymer material such as polyvinyl chloride (PVC). Other suitable materials for outer dielectric include various types of glass-filled nylon, polyethylene, polyurethane, and Teflon®.  
         [0025]     Referring again to  FIG. 2 , seal member  30  encloses and protects the interface between housing  16  and the portion of conductor assembly  18  projecting from the housing, thereby preventing flow of undesirable contaminants along conductor assembly  18  between outer dielectric  26  and housing  16 . An environmental seal is provided by one or more annular lips extending from external surfaces of seal member  30 . In the embodiment shown in  FIG. 2 , seal member  30  includes multiple lips  40   a - 40   d . Lips  40   a  and  40   b  provide bearing surfaces compressively engaging outer conductor  24 , and lips  40   c  and  40   d  provide bearing surfaces compressively engaging one or more external surfaces of housing  16 . Multiple lips  40   a - 40   d  also aid in distributing compressive loads on seal member  30  resulting from fluid pressure on the seal member. Seal member  30  may be formed from a moldable polymer material having elastomeric characteristics and resistance to hydrocarbon-based fluids and other fluids. Examples of suitable types of materials are thermoplastic polyester elastomers and high-temperature polyurethanes. One specific, non-exclusive example of a suitable material is Hytrel® thermoplastic polyester manufactured by DuPont®.  
         [0026]     In  FIG. 5 , like numerals are used to identify features similar to those identified in  FIG. 2 . Referring to  FIG. 5 , in an alternative embodiment, a seal member  31  incorporates a reinforcing member  32  for structurally reinforcing against loads experienced by seal member  31 . Reinforcing member  32  may be overmolded into seal member  31 , or the insert may be bonded to or otherwise placed into engagement with one or more surfaces of seal member  31 . Reinforcing member  32  may be formed from, for example, a suitable metal or polymer material.  
         [0027]     Referring to  FIGS. 1 and 6 , an annular insulator plug  45  is positioned around center conductor  20  proximate center dielectric  22 . Insulator plug  45  is generally cylindrical, with an inner surface formed into a first plurality of accordion folds  47  and an outer surface formed into a second plurality of accordion folds  49 . Accordion folds  47  engage an outer surface of center conductor  20  in a plurality of interference fits. In addition, accordion folds  49  engage an inner surface of outer conductor  24  in a plurality of interference fits. These interference fits aid in positioning and retaining plug  45  on first connector  12  during handling of first connector  12  and during mating of first connector  12  to second connector  14 . In addition, the interference fits prevent migration of contaminants along the annular passage extending between center conductor  20  and outer conductor  24 .  
         [0028]     In a manner described in greater detail below, an end portion of insulator plug  45  forms a flexible skirt  50  which stretches to extend around a portion of second connector  14  during and after mating of connectors  12  and  14 , thereby forming a seal around the contact interface when the connectors are mated.  
         [0029]     Plug  45  may be formed from a moldable polymer material having elastomeric characteristics and resistance to hydrocarbon-based fluids and other fluids. Examples of suitable types of materials are thermoplastic polyester elastomers and high-temperature polyurethanes. One specific, non-exclusive example of a suitable material is Hytrel® thermoplastic polyester manufactured by DuPont®.  
         [0030]     Referring to  FIGS. 1, 7  and  8 , second connector  14  includes an outer contact  60 , an inner contact  62  nested within a portion of the outer contact, and a housing  64  containing the inner and outer contacts. Referring to  FIGS. 7 and 8 , outer contact  60  includes a substantially cylindrical barrel portion  65  and a plurality of cantilevered blade portions  66  extending from the barrel portion in a first direction. A tail portion  67  extends from barrel portion  65  in a second direction generally opposite the first direction in which blade portions  66  extend. Tail portion  67  may be electrically connected to a conductive element, such as a wire or another terminal (not shown) using methods known in the art, such as soldering or resistance welding. A centerline C extending through the center of barrel portion  65  defines a mating axis of second connector  14 .  FIG. 8  shows a perspective view of the embodiment of outer contact  60  seen in  FIG. 7 .  
         [0031]     Each of blade portions  66  includes a formed end portion  68  having a first bend  69 , a first blade segment  70  flaring generally radially outwardly, a second bend  71  extending from blade first segment  70 , and a contact segment  72  extending from second bend  71 . As used herein with reference to second connector inner contact  62  and outer contact  60 , the term “bend” refers to any curved section of a contact, whether stamped or stamped and formed. Contact segments  72  are configured to project generally radially inwardly at an angle with respect to second connector mating axis C to form lead-ins for outer conductor  24  of first connector  12  during mating of the connector assembly. These lead-in features aid in locating and positioning first connector  12  with respect to second connector  14  during blind mating of the connectors. In addition, each contact segment  72  is configured with respect to its associated first blade segment  70  such that the contact segment is resiliently deformable with respect to the first segment  70 , along the directions indicated by arrows A 1  and A 2 . In this respect, contact segments  72  act as cantilever beam members having fixed ends extending from respective ones of second bends  71 . Each of contact segments  72  has a die break  73  provided along a radially innermost edge portion of the contact segment. Die breaks  73  serve as contact surfaces by which outer contact  60  engages an outer surface of outer conductor  24  of first connector  12  during mating. The provision of multiple flexible blade portions  66  and the provision of a die break  73  along each of flexible blade portions  66  help to ensure multiple, redundant contact points and sufficient normal force between outer conductor  24  and outer contact  60  under adverse environmental conditions (for example, during vibration of the connector assembly and/or in environments subject to extreme temperature variations.) Outer contact  60  is stamped and formed using known methods from sheet or strip of conductive metal or metal alloy, for example cartridge brass, beryllium copper, or copper covered steel.  
         [0032]     Referring to  FIGS. 7 and 9 , inner contact  62  includes a substantially cylindrical barrel portion  80  and a plurality of cantilevered blade portions  81  extending from the barrel portion in a first direction. A tail portion  82  extends from barrel portion  80  in a second direction generally opposite the first direction in which blade portions  81  extend. Tail portion  82  may be electrically connected to a conductive element, such as a wire or another terminal (not shown) using methods known in the art, such as soldering or resistance welding. A centerline extending through the center of inner contact barrel portion  80  is coaxial with centerline C of outer contact  60  defining a mating axis of second connector  14 .  
         [0033]     Referring to FIGS.  7  and.  9 , each of blade portions  81  includes a formed end portion  83  having a first bend  84 , a first blade segment  85  flaring generally radially outwardly, a second bend  86  extending from first blade segment  85 , and a contact segment  87  extending from second bend  86 . Contact segments  87  are configured to project generally radially inwardly at an angle with respect to second connector mating axis C to form lead-ins for center conductor  20  of first connector  12  during mating of the connector assembly. These lead-in features aid in locating and positioning first connector  12  with respect to second connector  14  during blind mating of the connectors. In addition, each contact segment  87  is configured with respect to its associated first blade segment  85  such that the contact segment is resiliently deformable with respect to the first segment  85 , along the directions indicated by arrows B 1  and B 2 . In this respect, contact segments  87  act as cantilever beam members having fixed ends extending from respective ones of bends  86 . Each of contact segments  87  has a die break  88  provided along a radially innermost edge portion of the contact segment. Die breaks  88  serve as contact surfaces by which inner contact  62  engages an outer surface of inner conductor  20  of first connector  12  during mating. The provision of multiple flexible blade portions  81  and the provision of a die break  88  along each of flexible blade portions  81  help to ensure multiple, redundant contact points and sufficient normal force between inner conductor  20  and inner contact  62  under adverse environmental conditions (for example, during vibration of the connector assembly and/or in environments subject to extreme temperature variations.) Inner contact  62  is stamped and formed using known methods from sheet or strip of conductive metal or metal alloy, for example cartridge brass, beryllium copper, or copper covered steel.  
         [0034]     Referring to  FIG. 7 , second connector housing  64  maintains a desired spatial relationship between inner contact  62  and outer contact  60 . Housing  64  is also shaped to provide surfaces for manipulation by a user or by an automated assembly device, for purposes of mating the first connector  12  with second connector  14 . Housing  64  is also shaped to provide surfaces that aid in locating and centering first connector  12  with respect to second connector  14  during mating of the connector assembly. In addition, housing  64  also aids in protecting inner contact  62  and outer contact  60  from damage.  
         [0035]     In the embodiment shown in  FIG. 7 , inner contact  62  and outer contact  60  reside within a cavity  64   a  formed in housing  64  and shaped to receive portions of conductor assembly  18  and/or first connector housing  16  therein during mating of the connector assembly, in a manner described in greater detail below. In addition, an annular shoulder  64   b  extends along an inner wall of interior cavity  64   a , for purposes described in greater detail below.  
         [0036]     Housing  64  may be formed from any rigid polymer material resistant to hydrocarbon-based fluids, such as polyvinyl chloride (PVC) or glass-filled nylon. Housing  64  may be fabricated by known methods (for example, by molding), after which the components of second connector  14  are positioned and secured within housing  64  using known methods, for example adhesives or interference fits. Alternatively, inner terminal  62  may be fixtured with respect to outer terminal  60 , and housing  64  may then be overmolded onto the fixtured components of second connector  14 .  
         [0037]     Referring to  FIG. 1 , the mating portion of first connector  12  is assembled by mounting seal member  30  onto conductor assembly  18  abutting housing  16 . A sleeve  90  is then slidingly fitted onto an outer surface of conductor assembly  18  such that seal member  30  is compressed between housing  16  and sleeve  90 . Housing  16 , seal member  30 , and a portion of sleeve  90  are positioned within a cavity formed in a piston rod  91  adapted for mounting these elements of first connector  12  therein. Seal member  30  is thus resiliently compressed between housing  16 , sleeve  90 , and a wall of the cavity in piston rod  91 , thereby forming a seal along the wall of the cavity.  
         [0038]     Mating of connectors  12  and  14  will now be discussed with reference to  FIGS. 1, 10 , and  11 .  
         [0039]      FIGS. 1 and 10  show different stages in the mating of connectors  12  and  14 . Referring to  FIGS. 1 and 10 , when it is desired to mate first connector  12  with second connector  14 , the portion of conductor assembly  18  extending from first connector housing  16  is inserted into second connector housing cavity  64   a , in the direction indicated by arrow D. The complementary shapes of first and second connector housings  16  and  64  aid in locating the connectors with respect to each other. Also, the complementary shapes of first and second connector housings  16 ,  64  and the lead-in structures provided by outer contact  60  and inner contact  62  of second connector  14  aid in centering outer conductor  24  with respect to outer contact  60 , and also aid in centering inner conductor  20  with respect to inner contact  62 . As first connector  12  is inserted into second connector  14  in the direction indicated by arrow D, die break  73  ( FIG. 7 ) formed along outer contact  60  engages an outer surface of outer conductor  24 . Similarly, die break  88  ( FIG. 9 ) formed along inner contact  62  engages an outer surface of inner conductor  20 .  
         [0040]     Referring to  FIG. 9 , as contact segment  87  of inner contact  62  is rotatable in the directions indicated by arrows B 1  and B 2 , contact segment  87  is able to deflect inward in direction B 1  during insertion of center conductor  20  into contact  62 , thereby reducing the insertion force needed for mating the connectors. Similarly, referring to  FIG. 7 , as contact segment  72  of outer contact  60  is rotatable in the directions indicated by arrows A 1  and A 2 , contact segment  72  is able to deflect inward in direction A 1  during insertion of outer conductor  24  into contact  60 , thereby reducing the insertion force needed for mating the connectors.  
         [0041]     Referring again to  FIGS. 1, 7 , and  9 , as first connector  12  is inserted more deeply into second connector housing cavity  64   a , bend  86  of inner contact  62  impinges on insulator plug  45 , tending to axially compress plug  45  in the direction indicated by arrow E ( FIG. 1 ). Continued motion of first connector  12  in direction D forces plug flexible skirt  50  to expand in direction D, thereby forming a shroud over the ends of inner contact blade portions  81 . Referring to  FIG. 1 , in this configuration, skirt  50  insulates and separates inner contact  62  from outer contact  60  during mating of the connectors. Skirt  50  also insulates and separates inner contact  62  from outer conductor  24  of first connector  12 .  
         [0042]      FIG. 1  shows engagement between inner conductor  20  and inner contact  62 , and between outer conductor  24  and outer contact  60  when the connectors are in their mated configuration. Connectors  12  and  14  are designed to be permanently mated. That is, the connectors are not intended to be unmated once they have been mated. The design of outer contact  60  and inner contact  62  are configured to maximize the force required to withdraw first connector  12  from second connector  14 , to aid in preventing unmating of the connectors. Referring to  FIGS. 1 and 11 , if a withdrawal force is exerted on first connector  12  in direction E (and/or a is force exerted on second connector  14  in direction D), engagement between outer contact die-break  73  and outer conductor  24  acts to resist withdrawal of outer conductor  24  from second connector  14 . Similarly, engagement between inner contact die-break  88  and inner conductor  20  acts to resist withdrawal of inner conductor  20  from second connector  14 . If the withdrawal force on first connector  12  is increased, outer contact die-break will tend to remain engaged with outer conductor  24 , forcing contact segment  72  of outer contact  60  to rotate in the direction indicated by arrow A 2 , and also forcing first segment  70  to rotate about first bend  69  in the direction indicated by arrow A 2 . Continued rotation of blade first segment  70  in direction A 2  causes first segment  70  to abut second connector housing shoulder  64   b , thereby preventing further rotation of first segment  70  about first bend  69 . In addition, referring to  FIG. 11 , an inner wall  64   c  of second connector housing cavity tends to restrict movement of the blade end portions of outer contact  60  by limiting rotation of first segment  70  about bend  69 . Thus, continued rotation of blade first segment  70  also causes second bend  71  to abut inner wall  64   c , thereby preventing further rotation of first segment  70  about bend  69 .  
         [0043]     Referring to  FIG. 9 , in a similar manner, inner contact die-break  88  will tend to remain engaged with inner conductor  20 , forcing contact segment  87  ( FIG. 9 ) of inner contact  62  to rotate in the direction indicated by arrow B 2 , and also forcing inner contact first segment  85  to rotate about first bend  84  in the direction indicated by arrow B 2 . Also, referring to  FIGS. 1 and 9 , flexible skirt  50  of insulator  45  tends to limit both rotation of contact segment  87  and rotation of first segment  85  due to withdrawal of inner conductor  20  from inner contact  62 .  
         [0044]     The sum effect of the interactions described above (between inner contact  62  and inner conductor  20  and also between outer contact  60 , outer conductor  24 , and second connector housing  64 ) is to resist unmating of first connector  12  from second connector  14 . When blade end portions  68  abut portions of second connector housing  64  and blade end portions  83  abut insulator  45  as described above, attempts to further withdraw outer conductor  24  and inner conductor  20  from second connector  14  may result in plastic deformation of blade end portions  68  and  83 , permanently damaging outer contact  60  and inner contact  62 .  
         [0045]     It should be understood that the preceding is merely a detailed description of various embodiments of this invention and that numerous changes to the disclosed embodiments can be made in accordance with the disclosure herein without departing from the spirit or scope of the invention. The preceding description, therefore, is not meant to limit the scope of the invention.