Abstract:
A 4.3/10 coaxial connector configured to receive a mating 4.3/10 connector includes: an inner contact; a dielectric spacer; and an outer contact, the dielectric spacer separating the inner contact and the outer contact. The outer contact includes an outer wall and a plurality of spring fingers, the spring fingers configured to deflect radially inwardly when the mating 4.3/10 connector is mated. The connector further comprises blocking structure that prevents mating of a Mini-Din connector.

Description:
RELATED APPLICATIONS 
       [0001]    The present application claims priority from and the benefit of U.S. Provisional Patent Application No. 62/156,131, filed May 1, 2015, 62/157,328, filed May 5, 2015, 62/157,805, filed May 6, 2015, and 62/157,868, filed May 6, 2015, the disclosures of which are hereby incorporated herein in their entireties. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to electrical connectors, and more specifically to coaxial connectors. 
       BACKGROUND 
       [0003]    Coaxial cables are commonly utilized in radio frequency (RF) communications systems. Coaxial connectors are typically attached to the ends of cables to enable the cables to be connected with equipment or other cables. Connector interfaces provide a connect/disconnect functionality between a cable terminated with a connector and a corresponding connector with a mating connector interface mounted on an apparatus or another cable. 
         [0004]    An RF coaxial connector interface commonly referred to as 4.3/10 is under consideration by the International Electrical Commission, an international standards body, to become a standardized coaxial connector interface as matter IEC(46F/243/NP). The 4.3/10 connector interface can be connected with a tool, by hand, or as a “quick-connect” connector. As shown in  FIGS. 1 and 2 , the 4.3/10 female connector  5  (shown on the left side of the figures) has an outer contact  10  with spring fingers  12  that engage an inner diameter of a mating interface cylinder  15  of the 4.3/10 male connector  20  (shown on the right side of the figures). Such engagement establishes electrical contact between the outer contacts of the connectors  5 ,  20 . 
         [0005]    Early adopters of the 4.3/10 connection interface have applied these connectors to communications equipment such as cellular base station antennas. In some cases, the same equipment includes connections for multiple types of connector interfaces, which are often selected based upon the diameter of each of the coaxial cables being connected to the device. 
         [0006]    One of these alternative connectors is referred to as 4.1-9.5 or “Mini-Din” connector. The Mini-Din male connector  25  (shown on the right side of  FIGS. 3 and 4 ) has a smaller overall connection interface that utilizes a similar but smaller diameter outer conductor connection cylinder  30 . The male outer conductor cylinder  30  includes a beveled and/or radiused outer leading edge  35  (see  FIGS. 4 and 10 ). The Mini-Din utilizes a coupling nut  40 ′ with the same threading configuration as the 4.3/10 coupling nut  40 . Because the Mini-Din connector  25  looks nearly the same and employs the same coupling nut  40 ′ as a 4.3/10 male connector  20 , an installer may mistakenly attempt to attach a Mini-Din male connector  25  to a 4.3/10 female connector  5 . If the initial resistance is overcome, the spring fingers  12  of the outer contact  10  of the 4.3/10 may be splayed outward (see  FIG. 5 ), thereby enabling insertion of the Mini-Din connector  25  to the point where the threads of the coupling nut  40 ′ threads are engaged. At this point, further threading of the coupling nut  40 ′, particularly with the force multiplying effect of the threads and ability to apply a wrench for additional leverage, may result in an erroneous interconnection. As shown in  FIG. 5 , the spring fingers  12  of the 4.3/10 outer contact  10  may be permanently splayed, thus preventing later interconnection with the correct 4.3/10 Male connector  20  (see  FIG. 6 ). In addition to destroying the female 4.3/10 connector  5 , which renders equipment upon which is mounted unusable, the erroneous connection with a Mini-Din connector  25  may enable damaging mis-directed transmission of improper power/signals to further downline equipment. 
         [0007]    In view of the foregoing, it may be desirable to provide an alternative connection interface that is compatible with existing 4.3/10 connectors. 
       SUMMARY 
       [0008]    As a first aspect, embodiments of the invention are directed to a similar interface blocking coaxial connector interconnectable with a 4.3/10 coaxial connector connection interface. The connector comprises: an inner contact defining a longitudinal axis; and an outer contact positioned radially outwardly from the inner contact and having axially-extending spring fingers. Each of the spring fingers includes a radially-inward protrusion projecting to an inner diameter less than an inner diameter of a male Mini-Din outer conductor cylinder. 
         [0009]    As a second aspect, embodiments of the invention are directed to a similar interface blocking coaxial connector, interconnectable with a 4.3/10 coaxial connector connection interface, comprising: an inner contact that defines a longitudinal axis; and an outer contact with a distal end and a plurality of spring fingers. The distal end is located such that the distal end interferes with a Mini-Din connector before contact occurs between the spring fingers and an outer conductor cylinder of the Mini-Din connector. 
         [0010]    As a third aspect, embodiments of the invention are directed to a similar interface blocking coaxial connector, interconnectable with a 4.3/10 coaxial connector connection interface, comprising: an inner contact defining a longitudinal axis; a cylindrical outer contact with a plurality of spring fingers; and a barrier plug retained proximate a distal end of the spring fingers that creates a stop face adjacent an inner diameter of the outer contact. 
         [0011]    As a fourth aspect, embodiments of the invention are directed to a 4.3/10 coaxial connector configured to receive a mating 4.3/10 connector, comprising: an inner contact; a dielectric spacer; and an outer contact, the dielectric spacer separating the inner contact and the outer contact. The outer contact includes an outer wall and a plurality of spring fingers, the spring fingers configured to deflect radially inwardly when the mating 4.3/10 connector is mated. The connector further comprises blocking structure that prevents mating of a Mini-Din connector. 
         [0012]    As a fifth aspect, embodiments of the invention are directed to a method of constructing a coaxial connector, comprising the steps of: 
         [0013]    (a) identifying a coaxial connector, comprising: an inner contact configured to be mated with an inner conductor of a coaxial cable; an outer conductor body configured to be mated with an outer conductor of the coaxial cable, the outer conductor extension having a first outer body with a gap; wherein the gap is configured to receive a free end portion of a mating connector to establish an electrical connection; and wherein the first outer body includes first fingers that generally form a ring and deflect a first deflection distance radially inwardly during engagement of the coaxial connector with the mating connector, wherein the deflected first fingers exert a radially outward force on the mating connector, and wherein the first fingers have a first length, a first width, and a first thickness; 
         [0014]    (b) selecting a second length, second width, and second thickness for second fingers of a second outer body, wherein the at least one of the second length, second width and second thickness differs from the first length, first width, and first thickness; 
         [0015]    (c) selecting a second deflection distance for the second fingers; wherein the selections of steps (b) and (c) induce a radially outward force that is substantially the same as the radially outward force defined in step (a); and 
         [0016]    (d) constructing the second outer body. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0017]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, where like reference numbers in the drawing figures refer to the same feature or element and may not be described in detail for every drawing figure in which they appear and, together with a general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the invention. 
           [0018]      FIG. 1  is a schematic side view of a 4.3/10 connection interface male and female connector pair aligned for interconnection. 
           [0019]      FIG. 2  is a schematic side view of the 4.3/10 connectors of  FIG. 1  mated together. 
           [0020]      FIG. 3  is a schematic side view of the 4.3/10 female connector of  FIG. 1  aligned for erroneous interconnection with a representative Mini-Din male connector. 
           [0021]      FIG. 4  is a schematic enlarged view of the connectors of  FIG. 3 , showing the minimal lip and beveled outer edge of the Mini-Din male connector that may be easily Overcome to initiate an erroneous interconnection. 
           [0022]      FIG. 5  is a schematic side view of the 4.3/10 female connector of  FIG. 3 , with the outer contact initially splayed to erroneously receive the Mini-Din male connector of  FIG. 3 , as the threads begin to mate. 
           [0023]      FIG. 6  is a schematic side view of a 4.3/10 female connector with its outer contact splayed by an erroneous connection with the Mini-Din connector as in  FIG. 5 , shown aligned with but no unable to mate with a 4.3/10 male connector. 
           [0024]      FIG. 7  is a schematic side view of an exemplary female connector according to embodiments of the invention, aligned for interconnection with a 4.3/10 male connector. 
           [0025]      FIG. 8  is a schematic side view of the female connector of  FIG. 7  interconnected with a 4.3/10 male connector. 
           [0026]      FIG. 9  is a schematic side view of the female connector of  FIG. 7  aligned for an attempted incorrect interface with a male Mini-Din connector, demonstrating the planar blocking face of the outer contact opposing the male Mini-Din male cylinder, thereby inhibiting splaying of the outer contact. 
           [0027]      FIG. 10  is an enlarged view of area B of  FIG. 9 . 
           [0028]      FIG. 11  is a plot of modeled electrical performance, comparing a conventional 4.3/10 female to 4.3/10 male interconnection and a the female connector of  FIG. 7  to 4.3/10 male interconnection. 
           [0029]      FIG. 12  is a schematic side view of a female connector according to embodiments of the invention, aligned for attempted interface with a male Mini-Din connector, demonstrating the interference between the connector body and the Mini-Din gasket, before the outer contact of the Mini-Din contacts the outer contact of the female connector, inhibiting splaying of the outer contact of the female connector. 
           [0030]      FIG. 13  is a close-up view of area C of  FIG. 12 . 
           [0031]      FIG. 14  is a schematic side view of the female connector of  FIG. 12  interconnected with a 4.3/10 male connector. 
           [0032]      FIG. 15  is a schematic isometric view of a barrier plug with an outer diameter groove. 
           [0033]      FIG. 16  is a schematic isometric view of an alternative barrier plug with retaining tabs. 
           [0034]      FIG. 17  is a schematic cut-away side view of the barrier plug of  FIG. 16 . 
           [0035]      FIG. 18  is a schematic isometric partial cut-away side view of a 4.3/10 female connector with a barrier plug according to  FIG. 15 , demonstrating the blocking face inhibiting advance of a Mini-Din connector. 
           [0036]      FIG. 19  is a schematic cut-away side view of a 4.3/10 female connector with a barrier plug according to  FIG. 16 , demonstrating the blocking face inhibiting advance of a Mini-Din connector. 
           [0037]      FIG. 20  is a close-up view of area B of  FIG. 19 . 
           [0038]      FIG. 21  is a schematic isometric cut-away side view demonstrating a 4.3/10 female connector with a barrier plug according to  FIG. 15 , demonstrating interconnection with a 4.3/10 male connector. Note the presence of the barrier plug does not inhibit interconnection with the intended mating connector. 
           [0039]      FIG. 22  is a schematic isometric front view of a sleeve-type barrier plug. 
           [0040]      FIG. 23  is a schematic isometric partial cut-away side view of a 4.3/10 female connector with a barrier plug according to  FIG. 22 , demonstrating the blocking face inhibiting advance of a Mini-Din connector. 
           [0041]      FIG. 24  is a schematic side cut-away view of the attempted interconnection of  FIG. 23 . 
           [0042]      FIG. 25  is a close-up view of area A of  FIG. 24 . 
           [0043]      FIG. 26  is a schematic isometric cut-away side view demonstrating a 4.3/10 female connector with a sleeve-type barrier plug according to  FIG. 22 , demonstrating interconnection with a 4.3/10 male connector. Note the presence of the barrier plug does not inhibit interconnection with the intended mating connector. 
           [0044]      FIG. 27  is a perspective view of the spring basket for an outer conductor body for the coaxial connector of  FIG. 7 . according to additional embodiments of the invention. 
           [0045]      FIG. 28  is an end view of the spring basket of  FIG. 27 . 
           [0046]      FIG. 29  is an end view of a spring basket for the outer conductor body of a coaxial connector according to still further embodiments of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0047]    The present invention is described with reference to the accompanying drawings, in which certain embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments that are pictured and described herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It will also be appreciated that the embodiments disclosed herein can be combined in any way and/or combination to provide many additional embodiments. 
         [0048]    Unless otherwise defined, all technical and scientific terms that are used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the below description is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this disclosure, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when an element (e.g., a device, circuit, etc.) is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. 
         [0049]    As described above, erroneous mating of a Mini-Din connector with a 4.3/10 connector can damage the 4.3/10 connector to the extent that it becomes unusable. Below are described different approaches for a coaxial connector interface that is mechanically and electrically compatible with the 4.3/10 interface specification, but which inhibits erroneous interconnection with similar coaxial interfaces like the Mini-Din connector. 
         [0050]    In one approach, it is recognized that, although the 4.3/10 interface includes a generally cylindrical space CS within the inner diameter of the fingers  12  of the outer contact  10  of the female connector  5  (best shown in  FIG. 2 ), because all of the electrical and mechanical interconnections are in fact made via the outer diameter of the fingers  12 , this cylindrical space CS is not a requirement to enable interconnection with a 4.3/10 interface. 
         [0051]    As shown in  FIGS. 7 and 8 , an exemplary female connector  105  includes an outer contact  110  with fingers  112  having inwardly-projecting protrusions  155  on their distal ends. The protrusions  155  provide additional surface area at the distal end to form blocking surfaces  160  (best shown in  FIG. 10 ) to the cylindrical space CS. The presence of the blocking surfaces  160  securely inhibits splaying of the outer contact spring fingers  112  if an interconnection with a Mini-Din connector is erroneously attempted by an installer. 
         [0052]    The blocking surfaces  160  comprising the distal end of each of the outer contact spring fingers  112  may be generally planar (e.g., they may be aligned normal to a longitudinal axis of the outer contact  110 ). The blocking surfaces  160  may form a discontinuous annular arrangement, with an inner diameter that is less than the inner diameter of the male Mini-Din outer conductor cylinder  25 , as shown in  FIGS. 9 and 10 . 
         [0053]    The inwardly-projecting protrusions  155  may be present proximate the distal end as lip or shoulder, or alternatively as a ramped surface wherein the thickness of the spring finger  112  increases from a proximal end to the distal end. Further, the inwardly-projecting protrusions  155  need not be applied to each of the outer contact spring fingers  112 , but may omit some (e.g., every other spring finger  112  may lack a protrusion  155 ) to form a blocking face that effectively inhibits erroneous mating with a Mini-Din connector  25 , as shown in  FIGS. 9 and 10 . However, because the outer diameter/surfaces of the outer contact  110  of the female connector  105  remain dimensionally unchanged, the female connector  105  remains electromechanically compatible with the full range of male 4.3/10 connectors  20 . 
         [0054]    The outer contact  110  may be a machined element, or alternatively may be formed via metal stamping or the like. 
         [0055]    Representative electrical modeling of the interface between the male 4.3/10 connector  20  and the female connector  105  demonstrates that the presence of the inward projecting protrusions  155  into the otherwise cylindrical space CS within the spring fingers  112  does not significantly degrade the electrical performance of an interface with the connector  105  compared to a conventional 4.3/10 connector interconnection (see  FIG. 11 ). One skilled in the art will appreciate that further tuning of the interconnection area may be applied to optimize performance at specifically desired frequency bands. Thus, the connector  105  can improve protection against connector interface damage by providing a block against interconnection with the easily confused variants of the 4.3/10 connection interface, without significantly impacting the electrical performance of the resulting interconnection. 
         [0056]    Referring now to  FIGS. 12-14 , another approach to preventing erroneous mating of connectors is shown therein. This approach recognizes that the 4.3/10 interface is capable of correctly mating over a range of insertion depths between the male and female connectors  5 ,  20 . Further, the Mini-Din connector  25  has a generally shallower configuration corresponding to the smaller connection surface diameters of the prescribed Mini-Din interface.  FIGS. 12 and 13  illustrate a female connector  205  with a connector body  235  that is longer than is typical. As a result, the outer contact  210  and inner contact  214  are seated deeper within the bore of the connector body  235 . Although sufficient depth is present to enable proper mating with a 4.1/10 male connector  20  (see  FIG. 14 ), when a male Mini-Din connector  25  attempts to mate with the female connector  205 , the distal end  237  of the connector body  235  bottoms against a gasket  37  of the Mini-Din connector  25  (see  FIGS. 12 and 13 ). As such, the outer conductor connection cylinder  30  of the Mini-Din connector  25  cannot splay the spring fingers  212  of the outer contact  210  of the 4.3/10 female connector  205  (best shown in  FIG. 13 ). Thus, the female connector  205  resists erroneous interconnection with a Mini-Din connector  25  which could otherwise damage it. 
         [0057]    The amount of extension applied to the connector body  235  may be selected, for example, to coincide with the maximum extension which enables correct seating of the inner and outer contacts of the 4.3/10 female connector  205  with a male connector  20  according to the 4.3/10 interface specification. Limiting dimensions include, for example, that the inner contact  214  is able to seat at a longitudinal location along the male center pin  24  of the male 4.3/10 connector  20  that enables secure electrical contact to occur. To enhance this dimension further, the inner contact  214  of the female connector  205  may be provided with enhanced inward bias, enabling secure contact to be applied even to a conical end portion of the male center pin  24 . This configuration can also allow for tolerance errors. Similarly, the outer contact  210  may be provided with a level of outward bias that enables the outer contact  210  to seat against at least a conical surface of interface cylinder  15  of a 4.3/10 male connector  20  (see  FIG. 14 ). 
         [0058]    Because the outer diameter and surfaces of the outer contact  210  of the female connector  205  remain dimensionally unchanged, the connector  205  remains electromechanically compatible with the full range of male 4.3/10 connectors  20 . However, the female connector  205  can improve protection against connector interface damage by providing a block against interconnection with the easily confused variants of the 4.3/10 connection interface without significantly impacting the electrical performance of the resulting interconnection. 
         [0059]    Referring now to  FIGS. 15-26 , another approach to prevent unwanted Mating of the 4.3/10 female connector is illustrated. This approach recognizes that the ability of the Mini-Din outer conductor connection cylinder  30  to fit within the outer contact of the female connector, thereby splaying the fingers radially outwardly, enables damaging erroneous interconnection between a female 4.3/10 interface and a male Mini-Din connector. As a solution, a female connector  305  includes a barrier plug  355  seated along the inner diameter of the outer contact  310 . The barrier plug  355  provides a stop face  352  aligned with a distal end of the outer contact  310  that is operative to prevent insertion of a Mini-Din outer conductor connection cylinder  30  within the outer contact  310  of the female connector  305 . 
         [0060]    The barrier plug  355  may be interlocked with the outer contact  310 . As one example, an inward protrusion of the outer contact spring fingers  312  keys with an outer diameter groove  354  of the barrier plug  355  (shown in  FIGS. 15, 18 and 21 ). In other embodiments, a barrier plug  355 ′ may be interlocked with the outer contact  310  via a seat  357  provided proximate the distal end of the spring fingers  312  that keys with a retaining tab  360  provided on the outer surface  370  of the barrier plug  355 ′ (see  FIGS. 16, 17, 19 and 20 ). Alternatively, protrusions provided on an outer surface of the barrier plug may key with corresponding grooves and/or bores provided in the spring fingers (and vice versa) in any configuration which retains the barrier plug  355  coupled with the outer contact  310 . 
         [0061]    To prevent the barrier plug  355  from interfering with the range of motion/outward bias of the spring fingers  312  required for secure engagement with the inner diameter of the conical surface of interface cylinder  15  of a 4.3/10 male connector interface (best shown in  FIG. 21 ), the barrier plug  355  may be formed with an interior ring  365  of relatively rigid/higher strength dielectric polymer and an outer surface  370  formed of an elastomeric dielectric polymer (either as an outer ring layer or plurality of outer nubs). Due to the elastomeric nature of the outer surface  370 , the presence of the barrier plug  355  may avoid interfering with the relative motion of the spring fingers  312  during initial interconnection alignment and/or negatively impacting the outward bias of the spring fingers, but still have sufficient strength to resist axial displacement along the bore in order to maintain a stop surface  352 . The stop surface  352  can prevent the cylinder  30  of a Mini-Din connector  25  from further axial insertion which would otherwise result in splaying the outer contact  310  (see  FIGS. 18-20 ). 
         [0062]    One skilled in the art will appreciate that the fit between the outer surface  370  and the spring fingers  312  (combined with the elastomeric properties of the outer surface material that is selected, such as silicon or the like) may also be configured to increase the outward bias of the spring fingers  312 , enabling a reduction in the bias properties required for the outer contact  310  alone. This configuration can enable the outer contact  310  to be provided with reduced dimensions and/or be formed of more cost efficient materials than may be possible without the presence of the barrier plug  355 . Alternatively, the outer surface  370  may be provided as the relatively rigid/higher strength dielectric polymer while the interior ring  365  is provided as elastomeric dielectric polymer. 
         [0063]    In further embodiments, a barrier plug  355 ″ may be formed as an axial extrusion of relatively rigid dielectric material positioned coaxially between the inner and outer contacts (see  FIGS. 22-26 ). The plug  355 ″ includes an outer sleeve  380 , an inner sleeve  382  and spokes  384 . The plug  355 ″ provides a plurality of apertures between the spokes  384  to minimize material requirements but can still withstand the expected axial insertion forces against the stop face from attempts to apply a Mini-Din connector or the like. 
         [0064]    One skilled in the art will appreciate that the application of a barrier plug  355 ,  355 ′,  355 ″ in the female connection interface of a 4.3/10 connector can improve protection against connector interface damage by providing a stop face against interconnection with the easily confused variants of the 4.3/10 connection interface, without significantly impacting the electrical performance of the resulting interconnection. 
         [0065]    As another approach to addressing incorrect mating with a 4.3/10 female connector, it may be desirable to provide a design in which the spring fingers are less susceptible to deformation and breakage. To that end, an additional embodiment of a spring basket  410  for a connector  405  is shown in  FIGS. 27 and 28 . The spring basket  410  has spring fingers  412  that form a gap with an outer conductor body like that shown at  210  above. As can be seen in  FIGS. 27 and 28 , the fingers  412  essentially define a ring with slots  413  formed in one end thereof, with the fingers  412  flaring radially outwardly slightly. 
         [0066]    It may be desirable for the fingers  412  to exert a similar radial force on the outer conductor body of a mating conductor as that exerted by the fingers  212  described above. For analytical purposes the fingers  412  can be approximated as cantilever beams. The force applied by a deflected cantilevered beam can be calculated as: 
         [0000]        N =(3 DEI )/ L   3   (1)
 
         [0000]    wherein 
         [0067]    N=the force normal to the beam (in this instance, the radial force generated by the finger  412 ); 
         [0068]    D=the amount of deflection experienced by the beam (i.e., the radial deflection of the finger  412 ); 
         [0069]    E=elastic modulus of the material of the beam/finger  412 ; 
         [0070]    I=moment of inertia through the cross-section of the beam/finger  412 ; and 
         [0071]    L=length of the beam/finger  412 . 
         [0000]    Thus, for two fingers  412  formed of the same material (such that E is the same in both equations) to exert a similar radial force N on a mating outer conductor, the geometry of the fingers  412  and the overall spring basket  410  may be adjusted. For example, if it is desired to provide a more robust finger  412  that is less susceptible to breakage, the thickness of the finger  412  may be increased. However, increasing the thickness raises the moment of inertia I, which in turn increases the radial force. In addition, a shorter finger  412  may also be less inclined to break under an axial load; however, a decrease in length may also raise the radial force. One manner of addressing the increased radial load is to decrease the amount of deflection induced by mating of the fingers  412  with a mating connector, particularly if the thickness is increased. 
         [0072]    For comparative purposes, in the embodiment of the outer conductor body  10  of  FIG. 7 , the fingers  12  may have a length of between about 0.252 and 0.260 inch, a width of 0.19 to 0.20 inch, a thickness of 0.012 to 0.015 inch, and a deflection distance of between 0.010 and 0.015 inch. As such, applying the concepts discussed above, the embodiment of the spring basket  410  of  FIGS. 27 and 28  would have the same width, but would have a decreased length of between about 0.230 and 0.24 inch and an increased thickness of between about 0.015 and 0.018 inch. This decrease in finger length would increase the radial force significantly, which can be counteracted by decreasing the deflection distance induced by mating to between 0.005 and 0.008 inch, with an outer diameter of the ring of fingers being between about 0.46 and 0.47 inch. This approach can generally maintain the radial force of the fingers  412 , strengthen the fingers  412  against breakage and/or deformation from the axial overloading of incorrect mating of connectors, and still provide a connector that conforms to the 4.3/10 guidelines. 
         [0073]    Notably, this concept can be applied not only to the spring basket discussed above, but also to other connectors conforming to the 4.3/10 interface guidelines that employ radial force between mating conductors, such as those shown in EP 2 304 851, incorporated herein by reference in its entirety. 
         [0074]      FIG. 29  applies the concept to a spring basket  510  that has a slightly different configuration, as the spring basket  510  has only six slots  513  (and therefore six fingers  512 ) rather than the eight slots  413  and eight fingers  412  discussed above. As can be seen in  FIG. 29 , the slots  513  are all oriented in the same direction (i.e., toward the top and bottom of the page in  FIG. 29 ), which can simplify manufacturing of the spring basket  510 , as the slots  513  may be formed by a saw or other cutting blade. Notably, the fingers  512  are of two different sizes: four fingers  512   a  are of a size similar to the fingers  412 , whereas two fingers  512   b  are slightly more than twice the size of the fingers  412 . As such, either the thickness or the induced deflection of the fingers  512   b  may be varied if the radial force is to be generally the same as for the fingers  512   a.    
         [0075]    While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus, methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of applicant&#39;s general inventive concept. Further, it is to be appreciated that improvements and/or modifications may be made thereto without departing from the scope or spirit of the present invention as defined by the following claims.