Patent Publication Number: US-6908325-B2

Title: Plug connector, consisting of a plug-in jack and a plug part

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. application Ser. No. 10/067,656, filed Feb. 4, 2002 now U.S. Pat. No. 6,773,285, issued Aug. 10, 2004. 
    
    
     TECHNICAL FIELD 
     The invention relates to a plug connector consisting of a plug-in jack and a plug part provided for insertion into the plug-in jack. More particularly, the invention relates to a so-called back-panel plug connector in which one of the two plug connector parts is mounted on a back-panel circuit board firmly mounted in a housing of an electrical device, the so-called motherboard, and the other part of the plug connector is mounted on a pluggable circuit board, the so-called plug-in card. When the plug-in card is inserted into the housing, the contacts of the plug-in jack and of the plug part, respectively, engage into the contacts of the other part so that the plug-in card is connected to the motherboard. 
     BACKGROUND OF THE INVENTION 
     There arises a problem in that the plug-in card cannot be guided so precisely in the housing that it can be inserted without any tolerances. This means that the contact pins and the contact jacks are laterally offset with respect to each other and/or may present a false angular position relative to each other in that moment when they hit each other during insertion of the plug-in card, i.e. that their longitudinal axes are out of alignment. The greater part of these alignment errors may certainly be corrected during insertion of the plug part into the plug-in jack; with this correction, however, comparatively high forces act on the contacts of the plug-in jack and the plug part. There is a risk that deformations and stresses on the soldering points of the contacts occur. This is especially critical for SMT connections which, in contrast to through contacts, are not positively connected with the circuit board. 
     BRIEF SUMMARY OF THE INVENTION 
     Thus, it is the object underlying the invention to provide a plug connector in which the contacts are not exposed to high mechanical loads during insertion of the plug-in card into the housing and, accordingly, of the plug part into the plug-in jack if there exists some misalignment between the plug part and the plug-in jack. 
     This is achieved in a plug-in jack comprising an insulating jack housing in which at least one jack contact is accommodated. The jack contact consists of a retaining part and a jack, the jack being mounted on the retaining part so as to be pivotable by a limited angle. The complementary plug part comprises an insulating plug housing in which at least one plug contact is accommodated, which is provided for engaging with the jack of the complementary plug-in jack. Since the jack is mounted so as to be pivotable on the retaining part, misalignments of the plug-in jack and the plug part relative to each other may automatically be compensated for. This prevents high mechanical loads from acting on the contacts. 
     According to a preferred first embodiment, it is provided that the retaining part of the plug-in jack comprises a head portion, an adjoining annular groove and a collar adjoining the annular groove and that the jack comprises a plurality of spring shackles engaging with the annular groove. On their free ends, the spring shackles preferably comprise hooks engaging with the annular groove. This makes it possible to mount the jack, in a very simple manner, to be pivotable on the retaining part. With its spring shackles, the jack is pushed over the head portion onto the retaining part, the spring shackles elastically widening when sliding over the head portion and subsequently snapping into the annular groove. There, the jack is reliably held by the hooks resting on the shoulder between the annular groove and the head portion while, at the same time, the jack may be pivoted by a certain angle. This angle is given by the difference between the width of the hooks and the width of the annular groove between the collar and the head portion. The higher this difference is, the farther the jack may be pivoted. 
     The jack is preferably barrel-shaped and is provided with several contact shackles at its end opposite the hook. The contact shackles widen elastically when the plug contact is pushed into the jack. The jack together with the spring shackles and the contact shackles may easily be produced in that a flat sheet stamping part is first provided with incisions so that the contact shackles and the spring shackles are formed, this stamping part then being rolled together to have the desired barrel-like shape. 
     According to the preferred first embodiment of the invention, the collar of the retaining part of the jack contact is adjoined by an anchor groove followed by an anchor portion accommodated in the jack housing, an annular spring being accommodated in the anchor groove, its edge facing the collar being beveled and the diameter of the collar and the head of the retaining part being less than the diameter of the anchor portion. This configuration makes it possible to assemble and mount the retaining part in the jack housing very easily. At first, the annular spring is pushed onto the anchor groove. Then the retaining part is pushed into an anchor opening in the jack housing from the rear side of the jack housing, the annular spring being elastically compressed when passing through the anchor opening and subsequently adopting its original shape again. Thus, there is formed a snap closure which makes it possible to push the retaining part into the jack housing, but impossible to pull it out in the opposite direction. In a similar manner, the plug contacts of the plug housing are received therein. 
     According to a preferred second embodiment, it is provided that the retaining part comprises a retaining opening and the jack comprises at least one hook engaging into the retaining opening. Here, it is preferably provided that the retaining part comprises a rectangular cross-section at least in the region of the retaining opening and that the jack is provided with two spring shackles which face each other in parallel and rest on two lateral faces of the retaining part facing away from each other. The hook may be formed by a sheet metal shackle bent from the spring shackle. The jack is reliably retained on the retaining part while the two other spring shackles resting on the retaining part make it possible, due to their elasticity, to pivot the jack in every direction on the retaining part. 
     It is preferably provided that the jack comprises two contact shackles facing each other in parallel and that the spring shackles face each other along a first direction being at right angles with respect to a second direction where the contact shackles face each other. The differing orientation of the contact shackles and the spring shackles ensures that a restoring force into the normal position is generated each time the jack is displaced from its normal position. 
     It is preferably provided that the jack is a bent sheet metal part having a closed center portion. Such a bent sheet metal part may be produced at low expenditure by stamping and bending a suitable metal sheet. 
     Preferably, both the retaining parts of the plug-in jack and the plug contacts of the plug parts each comprise an SMT connection which makes it possible to mount them on a circuit board via a surface mounting technique, favorable from a process engineering point of view. 
     Advantageous configurations of the invention may be taken from the subclaims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cut plan view of a plug-in jack and a plug part according to a first embodiment at the beginning of insertion; 
         FIG. 2  is a cross-section through the plug-in jack and plug part of  FIG. 1 ; 
         FIG. 3  is a view of the plug-in jack and the plug part during insertion, in correspondence with  FIG. 2 ; 
         FIG. 4  is a cross-section through the plug-in jack and plug part of  FIG. 3 ; 
         FIG. 5  is a cross-section through the plug-in jack and plug part in the completely assembled condition; 
         FIG. 6  is a cross-section through a plug-in jack and a plug part according to a second embodiment; 
         FIG. 7  is a cut plan view of the plug-in jack and the plug part of  FIG. 6 ; 
         FIG. 8  is a perspective view of the jack being used in the plug-in jack of  FIG. 6 ; 
         FIG. 9  is a perspective, enlarged view of one detail of the jack of  FIG. 8 ; 
         FIG. 10  is a further perspective view of the jack of  FIG. 8 ; 
         FIG. 11  is a further perspective view of the jack of  FIG. 8 ; 
         FIG. 12  is a perspective view of a jack according to a variant of the embodiment shown in  FIGS. 8  to  11 ; 
         FIG. 13  is a further perspective view of the jack of  FIG. 8 ; and 
         FIG. 14  is a further perspective view of the jack of FIG.  8 ; 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1 and 2  show a plug connector according to a first embodiment, which consists of plug-in jack  10  and plug part  50 . This concerns a so-called backplane plug connector in which the plug-in jack  10  is mounted on a motherboard  2  configured as a circuit board, and the plug part  50  is mounted on a plug-in card  4  equally configured as a circuit board. Motherboard  2  is part of an electric or electronic device in which the plug-in card  4  is inserted. The guide for plug-in card  4  in the device housing is not shown here. Of course, the structure of the plug connector may also be used for other fields of application. 
     The plug-in jack  10  comprises an electrically insulating jack housing  12  in which three cylindrical contact chambers are formed. In each contact chamber, there is disposed a jack contact  14  consisting of a retaining part  16  and a jack  18 . The retaining part comprises a head portion  20 , an annular groove  22 , a collar  24  adjoining the annular groove, an anchor groove  26 , an anchor portion  28  as well as an SMT connection  30 . The anchor portion is accommodated in an anchor opening  34  in jack housing  12 . Into anchor groove  26 , there is inserted an annular spring  32  which is supported between the collar  24  and a shoulder surrounding the anchor opening  34 . Annular spring  32  is beveled at its end facing the collar  24  and the diameters of the collar  24  and the head portion  20  are less than the diameter of anchor opening  34 . This makes it possible to insert the retaining part  16  into the jack housing  12  from the rear side thereof, that is from the left-hand side referring to  FIGS. 1 and 2 , until the annular spring has passed through the anchor opening  34  and is in the position shown in  FIGS. 1 and 2  in which it prevents the retaining portion from being retracted. 
     The jack  18 , which is mounted on the retaining portion, is a barrel-shaped bent sheet metal part. The jack  18  comprises a plurality of adjacent spring shackles  38  which are each provided with a hook  40  on their free ends, on the side facing the annular groove  22  (see more particularly FIG.  5 ). On the opposite end, there are formed several adjacent contact shackles  42 . The jack  18  is mounted on the retaining part  16  by pushing it onto the retaining part in the axial direction. In so doing, the spring shackles provided with the hooks slide over the head portion  20  until they snap into the annular groove  22 . Since the annular groove is longer than the hook  40  in the axial direction, jack  18  is pivotable on the retaining part by a defined angular range. This angular range is limited by the size of the contact chambers. 
     Plug part  50  comprises an electrically insulating plug housing  52  which is provided with a plurality of adjacent plug contacts  54  whose pin-shaped plug-in portion  56  is disposed in a contact chamber  58 . For anchoring the plug contacts  54  in the plug housing  52 , the same configuration is used as for the plug-in jack, i.e. annular springs  60  which are disposed in an anchor groove  61  and are supported between the collar  62  of the plug contact and a shoulder surrounding the corresponding anchor opening  64 , an anchor portion  63  of the plug contact  54  being disposed in the anchor opening  64 . Finally, each plug contact  54  is provided with an SMT connection  66  which is soldered onto the plug-in card  4 . 
       FIGS. 1 and 2  show the plug-in jack and the plug part at the beginning of insertion. Due to tolerances, the plug-in jack and the plug part are offset relative to each other in the x-direction and the y-direction by about 1 mm with respect to an optimal orientation in which the longitudinal axes of the plug part and the plug-in jack are aligned with each other. Lead-in bevels on the front edge of the jack housing and the plug housing result in that the misalignment is reduced during further insertion; in the condition represented in  FIGS. 3 and 4 , the misalignment Δx and Δy may be about ±0.4 mm. However, there was added an angular misalignment Δα and Δβ in the order of magnitude of about ±1.5° in each case. One may clearly see from  FIGS. 3 and 4  that, despite these misalignments, the plug-in portion  56  of the plug contacts  54  may easily be pushed into the jacks  18  since these are pivotally mounted on the retaining part  16 . In order to perform insertion without any problems, it is also supported by the conical configuration of the tip of the plug-in portion and the funnel-like configuration of the contact shackles  42  so that the jack  18  is automatically aligned properly. The potential pivoting range for the jack is selected such that in the case of larger misalignments the walls of the jack housing  12 , which surround the contact chambers, and the jack housing  52  bear against each other, without high mechanical forces acting on the plug contacts and the jack contacts in this position already. This condition may be seen in  FIGS. 3 and 4 ; the jack housing rests on the respective lower edge of the plug housing with respect to the Figures and provides mechanical support. 
     When the misalignment between the plug-in card and the motherboard is reduced during further insertion or when the misalignment is completely eliminated, the jack  18  reaches the position shown in  FIG. 5 , in which it extends in the longitudinal direction. 
       FIGS. 6  to  11  show a plug-in jack and a plug part according to a second embodiment of the invention. The same reference numerals are used for the components known from the first embodiment and reference is made to the above explanations. 
     Generally speaking, the difference between the first and second embodiments resides in that the retaining part  16  of the plug-in jack  10 , on which the jack  18  is mounted, as well as the plug-in portion  56  in the plug part  50  which is inserted into the jack  18 , each have a rectangular, flat cross-section. Correspondingly, the spring shackles  38  and the contact shackles  42  of the jack  18  are configured and disposed such that they face each other along a straight line. 
     As may be seen in  FIGS. 6 and 7 , the retaining part  16  of the plug-in jack  10  is realized with a flat, rectangular cross-section. At a distance from the free front end of the retaining part  16 , there is formed a retaining opening  70  which is rectangular. 
     On the retaining part  16 , there is mounted a jack  18  comprising four spring shackles  38  and four contact shackles  42  (see more particularly  FIGS. 8  to  11 ). The spring shackles and the contact shackles each start out from a center portion  72  which is configured as a closed, square-shaped ring. Jack  18  is a bent sheet metal part which is produced from a metal sheet through stamping and suitable bending. In order to close the center portion  72 , a connecting shackle  74  (see more particularly  FIG. 9 ) is provided on each outer side of the center portion, which is bent out of the plane of the center portion  72 , so that it may bear against the inner surface of the other side of the center portion. There, it is attached via spot welding, for instance. 
     Spring shackles  38  and contact shackles  42  face each other in pairs. Each spring shackle and each contact shackle are provided with a bent portion towards their free end so that contact surfaces are formed, which are facing each other and curved in one direction. 
     Two of the spring shackles  38  are provided with one hook  40  each (see  FIG. 11 , in particular) which is constituted by a bent-off shackle. Hooks  40  are formed on crosswise situated sprig shackles  38 . 
     Via the spring shackles  38 , the jack  18  is pushed onto the retaining part  16  such that the hooks  40  engage into the retaining opening  70  (see  FIG. 6 , in particular). Then, the jack  18  is fixed in the z-direction, but otherwise is mounted to be pivotable on the retaining part  16 . When there occurs a pivoting movement about the x-axis, the contact surfaces of the spring shackles  38  are displaced on the retaining part  16 , widening in the process. During a pivoting movement about the y-axis, the jack  18  is rotated about a pivot point which is roughly situated in the center of the retaining opening  70 . 
     The plug-in portion  56  is also configured with a flat, rectangular cross-section. Thus, the plug-in portion  56  may be pushed between the contact shackles  42  of the jack, which face each other in pairs; the contact shackles  42  then bear against the plug-in portion under line contact. 
       FIGS. 6 and 7  show that, due to the articulated attachment of the jack, it is possible that the latter is aligned such that, in case of possible misalignment between jack housing  12  and plug housing  52 , the plug-in portion  56  may easily be inserted between the contact shackles  42 . Since the orientation of the spring shackles is turned by 90° with respect to the orientation of the contact shackles, there always results a restoring force into the normal jack position when there is an oblique position of the jack between the retaining portion and the plug portion; namely, widening of the spring shackles  38  resulting from pivoting about the x-axis brings about resetting about the x-axis, while widening of contact shackles  42  resulting from pivoting about the y-axis brings about resetting about the y-axis. 
       FIGS. 12  to  14  represent a jack  18  according to a variant of the embodiment shown in  FIGS. 8 and 11 . The variant according to  FIGS. 12  to  14  concerns a bent sheet metal part; however, this one does not comprise a center portion  72 , but a square-shaped center plate  76 . The two spring shackles  38  extend in one direction, starting out from opposite edges of the center plate, and the two contact shackles  42  extend in the opposite direction, starting out from the two other edges. 
     This configuration substantially offers two advantages: On the one hand, the center plate has higher rigidity against torsion than the annular center portion  72 . On the other hand, the jack  18  may be produced much more easily since bending steps are necessary in two directions relative to center plate  76  only, namely upwards and downwards.