Abstract:
An electrical connection system, such as a Bayonet Niel-Concelman (BNC) connection system, includes two connector assemblies and enables electrical connections between the two connector assemblies to be established and maintained. The two connector assemblies respectively include a first connector and a second connector. One of the connector assemblies includes a contact pin, and the other connector assembly includes a mechanical support having a tapered recess. The first connector interlocks with the second connector, and the contact pin is received by the recess and engages the mechanical support, when the first and second connectors are interlocked. Because the recess is tapered, the contact pin is guided toward the center of the recess as the contact pin is pressed against the surface of the mechanical support exposed by the recess, making it easier to establish and maintain an electrical connection with the contact pin.

Description:
This is a continuation of application Ser. No. 09/316,228 filed May 21, 1999, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to electrical connections and, in particular, to a system and method for establishing and maintaining a removable connection between an electrical conductor of a first connector assembly and a contact pin of a second connector assembly. 
     2. Related Art 
     Various kinds of electrical connectors exist and have been used for decades to provide a removable electrical connection between various types of electrical components and devices. One such kind of removable electrical connector is known as a BNC or Bayonet Niel-Concelman connector. BNC connectors were developed many years ago and are typically used to connect coaxial (i.e., two conductor) cables, frequently in low-power, radio-frequency, and test applications, although they may be used in other applications as well. 
     FIG. 1 shows a typical female connector  11  and a typical male BNC connector  13  that are designed to engage and disengage with one another. The connectors  11  and  13  are two-conductor connectors, with one of the conductors being a center conductor  23  (which mates with a female receptacle  21 ), and the other conductor being a center terminal  33  (which mates with a sleeve  15 ). In many applications, the second conductor, i.e., the center terminal  33  and the sleeve  15 , are grounded, although that is not necessary. The sleeve  15  of the female connector  11  surrounds the female receptacle  21  and includes a pair of diametrically opposed engagement pins  17  and  19  that extend radially outward from the sleeve  15 . The male connector  13  includes a male BNC center terminal  33  having a center conductor  23 . The male connector  13  also includes a locking collar  29  having a pair of slots  25  and  27  that are adapted to engage the engagement pins  17  and  19  on the sleeve  15  of the female connector  11  to lock the connectors  11  and  13  together. 
     The female and male connectors  11  and  13  can be connected and locked together by first engaging the male BNC center terminal  33  with the sleeve  15  and then rotating the locking collar  29  to the locked position. This twist-lock coupling action is a central feature of the BNC connectors  11  and  13  and allows a reliable electrical connection to be made without the danger of the female and male connectors  11  and  13  gradually working loose or becoming accidentally unplugged. 
     Some male BNC connectors  13  are associated with additional contact pins (not shown by FIG. 1) that transmit signals in addition to the signals transmitted by center conductor  23  and center terminal  33 . These additional contact pins connect to conductive pads (not shown in FIG. 1) associated with the female connector assembly  11 . The conductive pads are usually formed on a flexible circuit (not shown) which transmits the signals received from the additional contact pins to other electrical devices. 
     However, the engagement pins  17  and  19  do not always keep the additional contact pins (not shown in FIG. 1) of the male BNC connector  13  precisely aligned with the conductive pads (not shown in FIG. 1) of the female BNC connector  11 . Furthermore, the additional male contact pins of the male BNC connector  13  and the conductive pads of the female BNC connector  11  are not typically aligned when BNC connectors  11  and  13  first engage (i.e., before the engagement pins lock the BNC connectors  11  and  13  together). Therefore, it can be difficult to establish an electrical connection between the additional contact pins and the conductive pads. 
     Thus, a heretofore unaddressed need exists in the industry for providing a system and method of establishing and maintaining an electrical connection between a female connector assembly and the contact pins of a male connector assembly. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the inadequacies and deficiencies of the prior art as discussed hereinbefore. Generally, the present invention relates to a system and method for establishing and maintaining electrical connections between connector assemblies. 
     The present invention utilizes a mechanical support, a conductive connection, and an electrical connector. The mechanical support has a tapered recess and a wall defining the tapered recess. The conductive connection is electrically coupled to the wall, and the electrical connector is coupled to the mechanical support. Because the recess is tapered, a contact pin from a connector assembly is automatically guided toward a center of the recess when the contact pin is received by the recess. Accordingly, an electrical connection between the conductive connection and the contact pin is easily established and maintained. 
     The present invention can also be viewed as providing a method for establishing and maintaining electrical connections between connector assemblies. Briefly described, the method can be broadly conceptualized by the following steps: providing a first connector assembly having a first electrical connector and a conductive pin; providing a second connector assembly having a second electrical connector coupled to a mechanical support, the mechanical support having a tapered recess, the recess defined by a wall of the mechanical support; interlocking the first electrical connector with the second electrical connector; passing the contact pin into the recess; engaging the mechanical support with the contact pin; and sliding the contact pin along a surface of the wall. 
     Other features and advantages of the present invention will become apparent to one skilled in the art upon examination of the following detailed description, when read in conjunction with the accompanying drawings. It is intended that all such features and advantages be included herein within the scope of the present invention and protected by the claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention can be better understood with reference to the following drawings. The elements of the drawings are not necessarily to scale relative to each other, emphasis instead being placed upon clearly illustrating the principles of the invention. Furthermore, like reference numerals designate corresponding parts throughout the several views. 
     FIG. 1 is a diagram illustrating a conventional Bayonet Niel-Concelman (BNC) connection system. 
     FIG. 2 is a diagram illustrating a male BNC connector assembly. 
     FIG. 3 is a diagram illustrating a female BNC connector assembly. 
     FIG. 4 is a diagram illustrating a more detailed view of a contact pin of the male BNC connector assembly of FIG.  2 . 
     FIG. 5A is a diagram illustrating a side view of a female BNC connector assembly in accordance with the present invention. 
     FIG. 5B is a diagram illustrating a front view of the female BNC connector assembly depicted by FIG.  5 A. 
     FIG. 5C is a cross-sectional diagram illustrating one of the tapered recesses shown by FIG.  5 B. 
     FIG. 6 is a cross-sectional diagram illustrating the recess of FIG. 5C when a contact pin is engaged with the outer surface of the mechanical support. 
     FIG. 7 is a cross-sectional diagram illustrating the recess of FIG. 6 when the contact pin is passing through the recess and is engaged with a slanted wall defining the recess. 
     FIG. 8 is a cross-sectional diagram illustrating the recess of FIG. 7 when the contact pin is aligned with the center of the recess and is engaged with opposite sides of the wall defining the recess. 
     FIG. 9 is a diagram illustrating a bottom view of another embodiment of a female connector assembly in accordance with the present invention. 
     FIG. 10A is a diagram illustrating the bottom view of the female connector assembly of FIG. 9 when a cover with tapered recesses has been formed and included in the mechanical support. 
     FIG. 10B is a top view of the female connector assembly of FIG.  10 A. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 2 depicts a male BNC assembly  42  that includes a male BNC connector  13  extending through a housing unit  39 . The center conductor  23  and the center terminal  33  of the male connector  13  are exposed through a hole in the housing unit  39 , as shown by FIG.  2 . The assembly  42  also includes a tab  41  that is coupled to the locking collar  29  (FIG.  1 ). The tab  41  may be rotationally moved to lock or unlock the male BNC connector  13  with a female BNC connector  11  of a female BNC connector assembly  45  (FIG.  3 ). The female BNC connector  11  includes a sleeve  15 , a female receptacle  21 , and engagement pins  17  and  19 . The connectors  11  and  13  may be connected and locked together by first engaging the male BNC terminal  33  with the sleeve  15  and then rotating the locking collar  29  via tab  41  to the locked position. 
     The male BNC connector assembly  42  also includes additional contact pins  52  for transmitting information additional to the information transmitted by center conductor  23  and center terminal  33 . The female BNC connector assembly  45  includes conductive pads  56  for interfacing signals with contact pins  52 . The pattern of the pads  56  preferably corresponds with the pattern of the contact pins  52  such that each contact pin  52  is engaged with a respective pad  56 , when the connectors  11  and  13  are engaged and are in the locked position. The pads  56  are formed on a flexible printed circuit that routes the signals interfaced with the pads  56  from/to other devices. Exemplary designs for the assemblies  42  and  45  are fully described in U.S. Pat. No. 5,857,866, entitled “Supplemental Electrical Connector for Mating Connector Pair” and filed on Mar. 14, 1997, which is incorporated herein by reference. 
     To ensure that each of the pins  52  is electrically connected to a respective pad  56 , each of the pins  52  is spring loaded. In this regard, the end of each pin  52  opposite of pad  56  (when the pin  52  is engaged with the pad  56 ) is coupled to a spring  62 , which is preferably housed within a sleeve  64 , as shown by FIG.  4 . Therefore, if any of the pins  52  engage one of the pads  56  before the other pins  52  engage the other pads  56 , the spring  62  of the engaged pin  52  is compressed until the other pins  52  also engage the other pads  56 . 
     A problem with the assemblies  42  and  45  is that precise rotational alignment between assemblies  42  and  45  is not guaranteed. Therefore, small variations in the rotational alignment may move some or all of the contact pins  52  out of alignment with their respective pads  56 . In this regard, if the assembly  42  rotates relative to the assembly  45 , some of the contact pins  52  may become separated from the pads  56 . The further a pad  56  and its respective contact pin  52  are from the center of rotation (i.e., from the center of center conductor  23 ), the more sensitive is the alignment of the pad  56  and pin  52  to the rotational movements of the assembly  42  relative to the assembly  45 . Although non-rotational alignment is not usually as significant of a problem as rotational alignment, any non-rotational movement between the assemblies  42  and  45  may also cause alignment problems between contact pins  52  and pads  56 . 
     Furthermore, establishing an electrical connection between one of the contact pins  52  does not necessarily guarantee that electrical connections exist between the remaining contact pins  52  and pads  56 . In this regard, the spring loaded design of the contact pins  52  allows the pins  52  to slightly move with respect to one another. Therefore, establishing an electrical connection with one of the contact pins  52  does not automatically establish and maintain an electrical connection with the remaining contact pins  52 , even when the male connector  13  is interlocked with the female connector  11 . 
     FIGS. 5A-5C show an improved design for a female BNC connector assembly  70 . The assembly  70  includes a mechanical support  74  which is coupled to and supports the sleeve  15 . The mechanical support  74  may be comprised of multiple portions and/or layers. For example, in the preferred embodiment, the mechanical support  74  is comprised of a base  75  and a printed circuit board (PCB)  76 . The base  75  may be a portion of an oscilloscope or other type of device, for example, and is preferably coupled to and supports the PCB  76 . As shown by FIG. 5B, the PCB  76  preferably includes conductive connections  79  and conductive pads  81 . Each of the conductive connections  79  shown in FIG. 5B is electrically coupled to a respective pad  81  at one end and to another device (not shown) at an opposite end and transmits electrical signals between the pad  81  and the other device. 
     As shown by FIGS. 5B and 5C, the mechanical support  74  (in particular the PCB  76  in the preferred embodiment) includes at least one recess  83  formed in a surface  85  of the mechanical support  74  for receiving a contact pin  52  (FIG.  2 ). In the preferred embodiment, each recess  83  is counter-drilled, as shown by FIG.  5 C. Therefore, at least a portion of each recess  83  is tapered such that a width (i.e., distance in the x-direction) of the recess  83  decreases in the y-direction. Consequently, the mechanical support  74  includes a slanted wall  87  that defines a recess  83  and that slants away from the surface  85  and toward the middle of the recess  83 , as shown by FIG.  5 C. 
     A portion of the wall  87  is preferably conductive and electrically coupled to a connection  79  so that the wall  87  may be used to communicate electrical signals between the connection  79  and a contact pin  52  (FIG.  2 ), when the contact pin  52  is engaged with the wall  87 . In the preferred embodiment, the wall  87  is formed by a conductive pad  81 , which has been plated or otherwise coupled to the PCB  76 , as shown by FIGS. 5B and 5C. 
     The recesses  83  are positioned on the surface  85  of the mechanical support such that each recess  83  receives a respective contact pin  52  (FIG.  2 ), as the male connector  13  is engaged with the female connector  11 . It is not likely that a contact pin  52  will be precisely aligned with the center of its respective recess  83  as the male connector  13  is engaged with the female connector  11 , as shown by FIG. 6, and the contact pin  52  either engages the slanted wall  87  of the recess  83  directly or first engages the outer surface  85  of the mechanical support  74 , depending on how closely the contact pin  52  is aligned with the center of the recess  83 . Since the contact pin  52  is spring loaded, the contact pin  52  includes some flexibility of movement, and as long the center of the contact pin  52  is aligned with a portion of the recess  83 , the contact pin  52  should be forced toward and eventually received by recess  83  as the contact pin  52  is pressed in the y-direction. Therefore, even when the contact pin  52  first engages the outer surface  85  of the mechanical support  74 , as shown by FIG. 6, the contact pin  52  should eventually be received by recess  83  and engage the slanted wall  87 , as shown by FIG.  7 . 
     As the contact pin  52  is pressed against the wall  87  with a force sufficient to overcome the friction between the wall  87  and the pin  52 , the contact pin  52  moves (i.e., slides) along the surface of the wall  87  toward the center of the recess  83 . In other words, the contact pin  52  is guided by the wall  87  toward the center of the recess  83 . Eventually, the pin  52  should engage an opposite portion of the wall  87 , as shown by FIG. 8, and be secured in the x-direction by the wall  87 . 
     In operation, a user engages the male connector  13  with the female connector  11  in an orientation such that each contact pin  52  is received by a respective recess  83 . At this point, the contact pins  52  are not necessarily aligned with the centers of their respective recesses  83 . As the assemblies  42  and  45  are pushed together by the user, each contact pin  52  engages a slanted wall  87  of a respective one of the tapered recesses  83 . The slanted wall  87  guides the contact pin  52  toward the center of the recess  83  as the assemblies  42  and  45  are further pushed together. 
     Once the connectors  11  and  13  are locked together, each contact pin  52  should be engaged with a wall  87  of a respective recess  83  and, therefore, should be electrically coupled to a conductive connection  79  (FIG.  5 B). Because wall  87  is slanted toward the middle of recess  83  in a direction away from surface  85 , the wall  87  tends to resist movement by the pin  52  away from the middle of recess  83 . Accordingly, it is not likely that small movements by the assembly  42  and/or  45  in a direction parallel with the surface  85  are likely to cause the pins  52  to become separated from the wall  87  and, therefore, to become electrically separated from their respective connections  79 . Consequently, for electrical separation to occur, it is likely that the pins  52  will have to move parallel to the y-direction. However, because of the design of the engagement pins  17  and  19  and connector  13 , inadvertent movements by the assembly  42  and, therefore, by the pins  52  in the y-direction are not likely to occur. This is especially true in embodiments in which the pins  52  are spring loaded, as described in U.S. Pat. No. 5,857,866. Consequently, once the pins  52  have been received by recesses  83  and the connectors  11  and  13  have been interlocked, it is likely that each pin  52  will have established and will maintain an electrical connection with the conductive portion of wall  87  and, therefore, with a respective conductive connection  79 . 
     Although the present invention may be implemented to establish and maintain an electrical connection with a single contact pin  52 , it should be noted that the present invention greatly simplifies the process of establishing and maintaining electrical connections with a plurality of contact pins  52 . In this regard, the user needs to ensure that only one contact pin  52  is received by the pin&#39;s respective recess  83  as the user mates the male connector  13  with the female connector  11 . Preferably, the user ensures that the contact pin  52  closest to the male connector  13  is received by its respective recess  83 , although it is possible for the user to focus on one of the other contact pins  52  instead. Once one of the contact pins  52  is received by its respective recess  83 , the remaining contact pins  52  should be automatically received by their respective recesses  83 , since the pattern of the recesses  83  should correspond to the pattern of the contact pins  52 . Therefore, electrical connections with the remaining contact pins  52  are automatically established and maintained. 
     It should be noted that it is not necessary for a portion of the slanted wall  87  to be conductive. For example, in an alternative embodiment, conductive pads  91  are formed on a non-recessed portion of the mechanical support  74 , as shown by FIG.  9 . Similar to the conductive pads  81  shown by FIG. 5B, the conductive pads  91  of FIG. 9 are preferably electrically coupled to conductive connections  79  that are routed to other devices (not shown). For example, similar to the embodiment shown by FIG. 5B, the conductive pads  91  and connections  79  may be formed on a PCB  76 . In another example, the conductive pads  91  may be formed on a flexible printed circuit (not shown) that similar to the PCB  76 , provides conductive connections  79  between the conductive pads  91  and other devices (not shown). Other designs for electrically connecting the pads  91  with other devices (not shown) may be employed without departing from the principles of the present invention. 
     Once conductive pads  91  have been formed, a cover  92  having tapered recesses  93  passing therethrough may be positioned over the pads  91 , as shown by FIGS. 10A and 10B. In FIG. 10A, base  75 , PCB  76 , pads  91 , and cover  92  collectively form the mechanical support  74 , and each of the pads  91  is exposed by a respective recess  93 . Therefore, the surface of each pad  91  exposed by the pad&#39;s respective recess  93  forms a wall of the recess  93 . As previously described for the preferred embodiment, each of the contact pins  52  is received by a respective recess  93  and engages a slanted wall  96  defining the recess  93  as the male connector  13  is mated with the female connector  11 . The slanted wall  96  guides the contact pin  52  toward the center of the recess  93 , and eventually the contact pin  52  engages the conductive pad  91  exposed by the recess  93 . Therefore, an electrical connection between the conductive pad  91  and contact pin  52  is easily established and maintained. 
     It should be noted that although the present invention has been described in the context of BNC connectors  11  and  13 , other types of connectors may be used to interlock or otherwise interconnect assemblies  42  and  45 . Furthermore, it should be emphasized that the above-described embodiments of the present invention, particularly, any “preferred” embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment(s) of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of the present invention.