Patent Publication Number: US-8540531-B2

Title: EMI connector ferrule and assembly combination therewith

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application Ser. No. 61/355,291, filed Jun. 16, 2010, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     This invention relates generally to electrical connectors and, more particularly, to connector ferrules configured to couple and ground a protective sleeve to and electrical connector. 
     2. Related Art 
     It is known to protect elongate wires with metallic protective sleeves to provide a shield against electromagnetic interference (EMI). It is further known to ground the protective sleeve via a ferrule to an upstream metal electrical connector. Unfortunately, the connection between the sleeve and the ferrule is typically located within the electrical connector, and thus, the assembly process is complicated and the sleeve can not be removed from the wires during service without first having to remove the ferrule from the electrical connector. In addition, there remains a need to improve the resistance to the ingress of fluid, e.g. water, into the electrical components of the electrical assembly, such as between the connection location of the protective sleeve to the ferrule and between the connection location of the ferrule to the electrical connector. Further yet, there remains a need to provide a ferrule that can be adapted to a variety of protective sleeve configurations without having to have a separate ferrule or protective sleeve configuration for individual applications. 
     SUMMARY OF THE INVENTION 
     A ferrule and assembly therewith constructed in accordance with the invention provides an economical, easy to assemble/disassemble, watertight, and otherwise reliable connection between a protective textile sleeve and an electrical connector, while also providing a reliable ground path between the textile sleeve and the electrical connector. 
     A ferrule configured to couple a textile sleeve to an electrical connector in accordance with one aspect of the invention has a cylindrical wall with an inner surface providing a cavity sized for receipt of an elongate electrical member therethrough. The cylindrical wall extends between a first end configured for attachment within a cavity of the textile sleeve and a second end having a radially outwardly extending annular rim configured for attachment to the electrical connector. The cylindrical wall has at least one radially outwardly extending annular bead adjacent the first end with the annular bead providing a radially inwardly facing annular pocket. Further, at least one seal member is disposed in the cavity for sealed abutment with the inner surface and the elongate electrical member. 
     In accordance with another aspect of the invention, a ferrule in combination with an electrically conductive textile sleeve, an elongate electrical member received in the textile sleeve, and an electrically conductive electrical connector is provided. The ferrule has a cylindrical wall with an inner surface providing a cavity sized for receipt of the elongate electrical member therethrough. The cylindrical wall extends between one end configured for attachment within an inner cavity of the textile sleeve and another end having a radially outwardly extending annular rim configured for attachment to the electrical connector. The cylindrical wall has at least one radially outwardly extending annular bead adjacent the end configured for attachment within the inner cavity of the textile sleeve with the annular bead providing a radially inwardly facing annular pocket. Further, at least one seal member is disposed in the cavity for sealed abutment with the inner surface and the elongate electrical member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other aspects, features and advantages of the invention will become more readily appreciated when considered in connection with the following detailed description of presently preferred embodiments and best mode, appended claims and accompanying drawings, in which: 
         FIG. 1  illustrates a cross-sectional side view of a ferrule constructed in accordance with one aspect of the invention shown received within a textile protective sleeve and an electrical connector housing in an initial state of assembly; 
         FIG. 1A  illustrates the ferrule of  FIG. 1  shown in a fully assembled state; 
         FIG. 2  illustrates a cross-sectional side view of a ferrule constructed in accordance with another aspect of the invention shown coupling a textile protective sleeve to an electrical connector housing; 
         FIG. 3  illustrates a cross-sectional side view of the ferrule of  FIG. 2  shown coupling a textile protective sleeve to an electrical connector housing in accordance with another aspect of the invention; and 
         FIG. 4  illustrates a cross-sectional side view of a ferrule constructed in accordance with yet another aspect of the invention shown coupling a textile protective sleeve to an electrical connector housing. 
     
    
    
     DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS 
     Referring in more detail to the drawings,  FIGS. 1  (partially assembled) and  1 A (fully assembled) illustrate a ferrule assembly  10  constructed in accordance with one aspect of the invention, wherein the ferrule assembly  10  includes at least a ferrule  12 , constructed in accordance with another aspect of the invention, an electrically conductive textile sleeve  14 , and an electrical connector  16 . The textile sleeve  16  can be provided having any suitable length to provide protection to an elongate electrical member  18 , whether a single electrical cable, bundled wire harness, or otherwise, extending therethrough and having any suitable diameter. Further, the textile sleeve  16  can be constructed having a circumferentially closes or open woven, knit or braided yarn structure, wherein the conductive aspect can be provided via electrically conductive yarns, coatings, films, foil, or otherwise. In addition, the conductive aspect of the electrical connector  16  can be provided via a separate conductive inner surface  20 , or the connector can be constructed having a conductive metal housing. The ferrule  12  is configured to couple the electrically conductive textile sleeve  14  to the electrical connector  16 , wherein the attachment of the sleeve  14  to the connector  16  is made external to the connector  16 , thereby providing an easy mechanism for attachment and detachment, such as may be required during service of at least one of the aforementioned components. In addition, the connection established by the ferrule  12  ensures a watertight seal is established and maintained between the ferrule  12  and the connector  16 , as well as between the ferrule  12  and the elongate electrical member  18 . 
     The ferrule  12  has a cylindrical wall  22  with an inner surface  24  providing a cavity  26  sized for receipt of the elongate electrical member  18  therethrough. The cylindrical wall  22  extends between a first end  28  configured for attachment within a cavity  30  of the textile sleeve  14  and a second end  32  having a radially outwardly extending annular rim  34  configured for attachment to the electrical connector  16 . The cylindrical wall  22  has at least one radially outwardly extending annular bead, and is shown here, by way of example and without limitation, as having a pair of annular beads  36 ,  38  adjacent the first end  28  with the annular beads  36 ,  38  providing radially inwardly facing annular concave pockets  40 ,  42 . The beads  36 ,  38  are spaced axially from one another by a radially outwardly facing annular recess  39  such that the recess  39  forms a valley between the upstanding beads  36 ,  38 . Respective seal members  44 ,  46  are disposed in the pockets  40 ,  42  for sealed abutment with the inner surface  24  and the elongate electrical member  18 . The seal members  44 ,  46  are shown as being o-ring type seals, though any suitable seal configuration can be used, depending on the geometry of the beads  36 ,  38 . 
     The rim  34  has an annular leg portion  48  that extends radially outward from the cylindrical wall  22 , shown as extending perpendicular from or substantially perpendicular from the cylindrical wall  22 , and a cylindrical outer lip portion  50  reverse folded in overlying relation to the cylindrical wall  22 , such that the outer lip portion  50  is aligned radially outwardly from the cylindrical wall  22 . As such, a generally c-shaped annular pocket  52  at the second end  32  is formed by the cylindrical wall  22 , the leg portion  48  and the lip portion  50  in open facing relation to the first end  28 . An outer surface  54  of the lip portion  50  is dimensioned for a close, line-to-line or slight interference fit within the electrical connector  16  such that an electrical connection is established between the ferrule  12  and the electrical connector  16 . 
     To facilitate establishing and maintaining a fluid-tight seal between the ferrule  12  and the electrical connector  16 , an elastomeric annular seal  56  is disposed between an outer surface of the cylindrical wall  22  and the inner surface  20  of the connector  16 . The seal  56  is illustrated as being received partially with the pocket  52 . The seal  56  has a radially outwardly extending sealing surface represented, by way of example and without limitation, as radially outwardly extending annular lips  58  configured for an interference fit against the connector  16  and a radially inwardly extending sealing surface represented, by way of example and without limitation, as radially inwardly extending lips  60  configured for an interference fit against the cylindrical wall  22 . 
     During assembly, the textile sleeve  14  is disposed over at least a portion the cylindrical wall  22  adjacent the first end  28 , either before or after the ferrule  12  is assembled within the electrical connector  16 , and then, to bring the ferrule  12  and seal members  44 ,  46  into their respective sealing abutment against the elongate electrical members  18 , an adjustable clamp ring  62  is disposed over the textile sleeve  14  and brought into radial alignment with the recess  39  between the beads  36 ,  38 . Then, the clamp ring  62  is tightened to constrict from its unclamped position, as shown in  FIG. 1 , to its reduced diameter, constricted position, shown in  FIG. 1A . Accordingly, the reduction in diameter of the clamp ring  62  causes the sleeve  14  and the ferrule  12  to be compressed radially inwardly, thereby compressing the seals  44 ,  46  between their respective bead pockets  40 ,  42  and an outer surface of the elongate electrical member  18 . 
     With the clamp ring  62  being received within the recess  39  between the beads  36 ,  38 , the clamp ring  62  is assured of being maintained in its clamping position on the ferrule  12 , wherein the clamp ring  62  is restricted against possible axial movement by the beads  36 ,  38 . Further, with the clamp ring  62  being readily accessible axially outwardly from the electrical connector  16 , the clamp ring  62  can be selectively removed easily during service without having to first remove the ferrule  12  from the connector  16 . 
     In  FIG. 2 , a ferrule assembly  110  constructed in accordance with another aspect of the invention is illustrated, wherein the same reference numerals used above, offset by a factor of 100, identify similar features. 
     The ferrule assembly  110  includes at least a ferrule  112 , constructed in accordance with another aspect of the invention, an electrically conductive textile sleeve  114 , and an electrical connector  116 . Further, as in the previous embodiment, the assembly  110  includes a seal  156  to establish a fluid-tight seal between a cylindrical wall  122  of the ferrule  112  and the connector  116 . The cylindrical wall  122  extends between a first end  128  configured for attachment within a cavity  130  of the textile sleeve  114  and a second end  132  having a radially outwardly extending annular rim  134  configured for attachment to the electrical connector  116 . The cylindrical wall  122  has a radially outwardly extending annular bead, shown as a half bead  136 , extending to the first end  128  with the annular bead  136  providing a radially inwardly facing annular pocket  140  and a radially outwardly facing recess  139  between the half bead  136  and the rim  134 . An elastomeric seal member  144  is disposed in the pocket  140  for sealed abutment with an inner surface  124  of the ferrule half bead  136  and an outer surface of an elongate electrical member  118 . The seal member  144  is shown as being generally rectangular in cross-section, though any suitable seal configuration can be used, depending on the geometry of the bead  136  and the pocket  140 . The annular rim  134  is configured the same as discussed above, and thus, is not discussed further. The primary difference between the embodiments  12 ,  112  being the difference in the respective bead constructions. 
     To bring the ferrule  112  and seal member  144  into their respective sealing abutment against the elongate electrical member  118 , an adjustable clamp ring  162  is disposed over the textile sleeve  114  in radial alignment with the recess  139 . Then, the clamp ring  162  is tightened to a constricted, reduced diameter configuration. Accordingly, the reduction in diameter of the clamp ring  162  causes the sleeve  114  and the first end  128  of the ferrule  112  to be compressed radially inwardly, thereby compressing the seal  144  between the inner surface of the bead pocket  140  and the outer surface of the elongate electrical member  118 . 
     With the clamp ring  162  being received within the recess  139  between the bead  136  and the seal  156 , the clamp ring  162  is assured of being maintained in its clamping position on the ferrule  112 , wherein the clamp ring  162  is restrained against axial movement. Further, with the clamp ring  162  being readily accessible axially outwardly from the electrical connector  116 , the clamp ring  62  can be removed easily during service without having to first remove the ferrule  12  from the connector  16 , and thus, the sleeve  114  can be easily removed as desired. 
     In  FIG. 3 , a ferrule assembly  210  constructed in accordance with another aspect of the invention is illustrated, wherein the same reference numerals used above, offset by a factor of 200, identify similar features. 
     The ferrule assembly  210  has a ferrule  212  constructed the same as the ferrule  112  discussed above, and thus, is not discussed in further detail. The notable difference is in how a clamp ring  262  is position and fastened about the ferrule  212 . To bring the ferrule  212  and seal member  244  into their respective, clamped sealing abutment against an elongate electrical member  218 , the radially adjustable clamp ring  262  is disposed over the textile sleeve  214  in radial alignment with a half bead  236  of the ferrule  112  and the seal  244  is disposed within a radially inwardly facing pocket  240  formed by the half bead  236 . Then, the clamp ring  262  is constricted radially inwardly to a reduced diameter position. Accordingly, the reduction in diameter of the clamp ring  262  causes the sleeve  214  and the ferrule  212  to be compressed radially inwardly, thereby compressing the seal  244  between the bead pocket  240  and the elongate electrical member  218 . 
     In  FIG. 4 , a ferrule assembly  310  constructed in accordance with another aspect of the invention is illustrated, wherein the same reference numerals used above, offset by a factor of 300, identify similar features. 
     The ferrule assembly  310  has a ferrule  312  constructed similarly as described and illustrated for the ferrule  12 , with the exception being that the ferrule  312  has a cylindrical wall  322  having a single annular bead  336  adjacent its first end  328 . And so, unlike the embodiment of  FIGS. 1 and 1A  wherein a clamp ring is clamped between the pair of axially spaced beads, a clamp ring  362  is fastened about the cylindrical wall  322  adjacent the single bead  336 , wherein the clamp ring  362  is disposed between the bead  336  and a rim  334  of the ferrule  312 . The rim  334  is constructed the same as discussed above with regard to the rim  34 , and thus, is not described in further detail. 
     To facilitate establishing and maintaining a fluid-tight seal between the ferrule  312  and an electrical connector  316 , an elastomeric annular seal  356  is disposed between an outer surface of the cylindrical wall  322  and the inner surface  320  of the connector  316 . The seal  356  is illustrated as being received partially with a pocket  352  of the rim  334 , as discussed above. The seal  356  is generally flush with a second end of the connector  316 , with the clamp ring  362  being disposed between the seal  356  and the bead  336 , such that the bead  336  acts as a stop surface to prevent axial movement of the clamp ring  362  upon being fully assembled. As in the previous embodiments, the clamp ring  362  remains disposed axially outwardly from the connector  316  upon being clamped, thereby allowing easy access to the clamp ring  362  for servicing purposes. To further facilitate establishing a fluid-tight seal between the ferrule  312  and an elongate electrical member  318 , an annular seal  344  is disposed between an inner surface  324  of the ferrule  312  and the elongate electrical member  318 . The seal  344  is represented here as being fixed to the inner surface  324 , such as by being bonded or otherwise adhered to the cylindrical inner surface  324  between the bead  336  and the rim  334 . The seal  344  can be provided as a material coating, plated surface, etched surface, or co-injected material, for example. Thus, rather than requiring a separate, loose component to perfect a seal between the ferrule  310  and the elongate electrical member  318 , the seal  344  is fixed to the inner surface  324  of the ferrule  312  as a single piece component therewith. 
     Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.