Patent Publication Number: US-6908346-B1

Title: Quad cable interface using available insert

Description:
BACKGROUND OF THE INVENTION 
     A standard aircraft Ethernet interconnect system (for carrying high rate bits between computer circuits on the aircraft) uses a special quad cable that has four individually insulated conductors and a grounded main shield around the conductors, and has a 100 ohm characteristic impedance. The four cable conductors are terminated to contacts of a Quadrax connector that is inserted into a bore of a specialized metallic insert having several bores and holding specialized contacts that connect the four Quadrax contacts to terminals. A common type of such terminals includes socket contacts that project from a connector that is mounted on a circuit board. The special metallic insert that receives the Quadrax connector is expensive. 
     A low cost header for connecting other pairs of contacts includes a plastic molded frame having multiple rows and columns of passages and a double-ended pin in each passage. The rear ends of the passages can receive terminals of a mating connector. It would be desirable if the front ends of the insert pins could electrically mate with the contacts of the Quadrax type connector. The much lower cost of the molded plastic insert would greatly reduce the cost of the Ethernet connector system. 
     SUMMARY OF THE INVENTION 
     In accordance with one embodiment of the present invention, a connection system is provided for connecting insulated conductors of a quad cable to terminals, using an insert of the type that has a molded plastic insert frame with multiple rows and columns of passages that each holds a double-ended pin. The mating ends of the pins are engaged with the terminals, and the present invention provides means for connecting conductors of the quad cable to rear ends of the pins that lie within the insert frame. 
     Applicant provides a cable-connected quad terminator with four contacts surrounded by a terminator main shield. Rear ends of the terminator contacts are terminated to the four cable conductors, while mating ends of the terminator contacts project forward of the terminator main shield. Applicant also provides a backshell adaptor having through bores into which the quad terminator can be inserted, the adaptor having retainers that removably retain the quad terminator in a fully installed position wherein mating ends of the contacts and subshields around each contact, project forward of the backshell adaptor. The backshell adaptor has a front face lying facewise adjacent to the rear end of the insert, with the four projecting parts of the terminator contacts and the subshields projecting into four corresponding passages of the insert frame. Each contact projecting part engages a rear end of a pin lying in an insert passage to complete the connection. 
     The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded front isometric view of a connection system of the present invention. 
         FIG. 2  is a rear isometric view of the quad terminator of the system of  FIG. 1 , and also showing, in phantom lines, the rear shield of a prior art Quadrax connector. 
         FIG. 3  is a partial sectional view of the system of  FIG. 1 , with all parts fully connected. 
         FIG. 4  is a sectional view of the quad cable of FIG.  3 . 
         FIG. 5  is a rear elevation view of the quad terminator of FIG.  2 . 
         FIG. 6  is a rear elevation view of a portion of the insert of  FIG. 1 , and also including circles indicating the outlines of the terminator main shields of the quad connector of FIG.  1 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  shows a connection system  10  for connecting conductors of a Star Quad cable  12  to terminals  14  of a connector  16 . Each terminal  14  lies within a miniature stainless steel subshield  20 . Such connectors  16  are commonly used in Ethernet connection systems on aircraft, to carry high speed data signals between computer circuits. Previously, a special metallic insert was used with a special Quadrax connector that was terminated to conductors of the cable  12 , to connect to the another Quadrax connector in a special metallic insert. Such special metallic inserts were expensive. 
     It has occurred to applicant that a Standard insert  30  of a type that includes a molded plastic frame  32  and multiple double-ended insert contacts, or pin contacts, or pins  34  might be used instead to make connections between the cable conductors and the terminals  14 . The standard insert  30  is widely available at low cost and is commonly used as a header to connect pairs of socket contacts. In many uses, the standard insert  30  is mounted in a bay  40  of a mounting shell  42 . The particular shell  42  is of a type that has three bays  40 ,  44 ,  46 , with a rearwardly R facing shoulder  50  in each bay that engages a forwardly-facing shoulder  52  molded into the insert frame  32 . The shell also has threaded holes  54  around each bay for mechanical connection to devices, and has flanges with unthreaded holes  56  for mounting the shell on other equipment. 
     In accordance with the present invention, applicant provides a quad terminator  60  which is terminated to the four conductors of the quad cable  12 , and applicant also provides a backshell adaptor  62  that enables the four contacts of the quad terminator  60  to electrically connect to four pins  34  of the standard insert  30 .  FIG. 4  shows that the quad cable  12  includes four conductors  71 - 74 , four insulators  76 - 79 , each insulator surrounding a conductor such as  71  along the length of the conductor (except where it is bared to make a connection). The quad cable also has a grounded cable shield  75 .  FIG. 2  shows that the quad terminator device, or quad terminator  60  has four contacts  82  that each has a rear end  84  that is terminated to a cable conductor such as  72  of the cable and that has a front end  86 . The terminator has a terminator shell or main shield  90  with a step at  92 , that encloses parts of the cable conductors such as  72  at rear ends  84  of the contacts. The quad terminator also has four subshields  96  that each surrounds only one of the contacts  82 . The subshields each have mating ends with tapered entrances  102  that can receive a pin end. The subshields  96  are preferably formed of stainless steel, and are separated from each other and from the main shield  90  by the insulation  94 . It is noted that applicant&#39;s quad terminator  60  is largely similar to prior Quadrax connectors, except that the present quad terminator  60  is devoid of a main shield front end indicated at  104  that previously surrounded the mating ends of the contacts  82  and the mating ends of the subshields  96  that surround the contacts. Applicant&#39;s contact mating ends and subshields project forward of a front end  106  of the main shield  90  and of the insulator. 
     The backshell adaptor  62  shown in  FIG. 1  has a plurality of bores  110  that are each constructed to receive and retain a quad terminator  60  of the construction shown in FIG.  2 . It is noted that each bore  110  has a polarizing groove  112  that corresponds to a polarizing projection  114  in each quad terminator to fix the orientation of the terminator. The backshell adaptor has sideward projections  116  with fastener-receiving holes  120  that each receives a fastener  122  with a threaded end that can thread into a corresponding one of the hole  54  in the shell  42 . 
       FIG. 3  illustrates the manner in which the insert is used to connect the terminals  14  of the connector  16 , to the conductors such as  72  of the quad cable  12 . The backshell adaptor  62  has a retainer  130 , the particular retainer shown including the common clip type with resilient tines  140  that abut the rearwardly-facing shoulder  92  on the terminator main shell  90 . When the quad terminator  60  is fully installed in the backshell adaptor  62 , the mating ends  86  of the terminator contacts project forward of a front face  142  of the backshell adaptor, as do the subshields  96 . When the backshell adaptor is mounted on the mounting shell  42 , the front face  142  of the backshell adaptor lies substantially facewise against a rear face  144  of the insert  30 . By “substantially” applicant means that there is no more than a small gap between the faces  142 ,  144 , which must be small enough to assure that the contact front mating ends  86  can fully engage the rear ends  150  of the pins  34  of the insert  30 . Each pin  34  has rear and front ends  150 ,  152  and has a middle  154  that is captured in the insert frame  32 . Applicant shows clips with tines  160  that releasably retain the pin middles portions. However, it is also possible to overmold the insert frame  32  around the pin middle portions to lock the pins in the frames. 
     As shown in  FIG. 1 , the insert frame  32  has multiple through passages  170  that each extends between the rear and front faces or ends  144 ,  146  of the insert frame. The standard insert  30  has one hundred-fifty passages arranged in ten horizontal rows and fifteen vertical columns, each passage normally holding a pin  34 . The passages of each row are spaced at a pitch of 0.1 inch. As shown in  FIG. 3 , each terminator contact front end  86  and the subshield  96  that surrounds it, are each forwardly insertable into a rear end  172  of an insert passage  170 . The passage front end  174  similarly receives a terminal  14  and a surrounding terminal subshield  20 . 
     The backshell adaptor  62  of  FIG. 1  has twelve bores  110  arranged in four horizontally-extending rows and three vertically-extending columns. Additional backshell adaptors can be used in connection with another insert lying in bay  46 , and a double-length backshell adaptor can be used to hold two inserts in the two bays  40 ,  44 . 
       FIG. 6  shows the outlines at  180 ,  182  of the main shields  90  of two quad connectors, or terminators  60 ,  60 A whose contacts and the corresponding subshields have been inserted into passages  170  of the insert  30 . The contacts and subshields of the first terminator  60  enter four passages of a first group  191  of four passages. The second terminator  60 A, has contact rear ends that enter passages of a second group  192  of four passages. The two groups  191 ,  192  of four passages each, must be separated sufficiently to at least account for the thickness of the walls between bores of the backshell adaptor. As a result, at least two passages  170 A lie between the two groups  191 ,  192  of four passages each. Accordingly, applicant&#39;s backshell adaptor is provided with only twelve bores that hold twelve quad terminators, to engage pins in only forty-eight of the total of one hundred fifty passages  170  of the insert  30 . The fact that one hundred two passages of the insert are not used, does not detract from the fact that the insert  30  is of much lower cost than a prior art special metal insert that was used. 
     The quad terminator  60  can be used to connect to substantially any equipment that previously connected to a Quadrax connector which was of similar design but with a main shield front end surrounding the projecting subshields and the contact front ends, except that the present grounded main shield  90  is not as accessible for a grounding connection. 
     Thus, the invention provides a connection system for connecting conductors of a quad cable to a device that includes socket contacts of a size (with subshields) that can enter passages in an insert. This is accomplished by terminating the cable conductors to contacts of a quad terminator that is similar to a prior Quadrax connector, but without a main shield front end. Also, a backshell adaptor is provided with bores that each receives and retains a quad terminator, with the rear ends of the contacts and of the subshields projecting from the front face of the backshell adaptor. The backshell adaptor, preferably with at least one quad terminator installed therein, is pressed towards a rear end of a standard insert until the front ends of the terminator contacts and the subshields around them, each enters a separate one of the insert passages, and the contacts mate to rear ends of double-ended contacts, such as double-ended pins, in the insert frame passages. The backshell adaptor is mounted in place, as by mounting it on a mounting shell with at least one bay that receives the insert. 
     The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.