Abstract:
A modular jack for receiving an RJ-45 plug and for blocking insertion of an RJ-11 plug is disclosed. The modular jack has stamped and formed deflection members having retention sections, ramp surfaces and blocking tabs extending from ends of the ramp surfaces. The blocking tabs project laterally inwardly toward the plug-receiving cavity and block an RJ-11 plug from being inserted into the modular jack. An RJ-45 plug is wider than the RJ-11 plug and engages the ramp surfaces of the deflection members to deflect the blocking tabs away from the plug-receiving cavity, thereby allowing insertion of the RJ-45 plug.

Description:
FIELD OF THE INVENTION 
     The present invention relates to receptacle connectors for modular plugs. In particular, the invention is directed toward a receptacle connector having a deflectable blocking member for selectively receiving a specific sized modular plug. 
     BACKGROUND OF THE INVENTION 
     Modular jacks which receive RJ-11 and RJ-45 type modular plugs are well known in the communications and computer industries. Often, communications and computer equipment are outfitted with both RJ-11 and RJ-45 modular jacks. Of course, each of these RJ-11 or RJ-45 modular jacks are intended to receive only an RJ-11 or RJ-45 plug, respectively. However, frequently placement of the modular jacks within electronic equipment is in a location which does not lend itself to easy visual inspection. For instance, desk top computers commonly have input/output connectors placed on a rear panel of the computer chassis. As such, often RJ-11 and RJ-45 modular jacks are located side by side on the rear of a piece of electronic equipment or in another limited access area. Both aesthetics and system architecture dictate placement of modular jacks and, therefore, selection of their location is a limited option. 
     Since access to the modular jacks on a piece of electronic equipment is often restricted, insertion of a modular plug into a modular jack is frequently performed without visual verification. Thus, it is possible that during blind installation of a modular plug into a modular jack, an equipment operator may incorrectly align an RJ-45 plug with an RJ-11 jack or an RJ-11 plug with an RJ-45 jack. Misaligning an RJ-45 plug with an RJ-11 jack is of little concern because an operator will quickly notice that the RJ-45 plug is larger than the plug receiving cavity of an RJ-11 jack. In fact, due to the size differential, engagement of an RJ-45 plug and an RJ-11 jack is impossible. However, misalignment of an RJ-11 plug with an RJ-45 jack creates a serious concern. An RJ-11 plug will fit within an RJ-45 jack, often quite comfortably. In such an event, an operator will actually hear the audible click of the modular plug latch snapping into place within the modular jack and feel what seems to be proper mating of a modular plug within a modular jack. Moreover, the RJ-11 plug will be inserted far enough into the RJ-45 modular jack to allow electrical contacts on the plug to electrically engage electrical contacts of the jack. This can lead to severe damage to the electronic equipment because certain modular plug contacts may be carrying higher current than the electronic equipment circuitry is intended to receive from a respective electrically engaged modular jack contact. For instance, a power line from an RJ-11 plug may improperly become electrically engaged with what was intended to be a signal line within the RJ-45 modular jack. 
     Furthermore, even if an operator recognizes that an RJ-11 plug was mistakenly inserted into an RJ-45 jack, the RJ-45 jack will likely have sustained permanent damage to the contacts since the RJ-11 plug tends to deform the outer-most RJ-45 contacts, by laterally bending them out of their original position. 
     SUMMARY OF THE INVENTION 
     Accordingly, a modular jack is needed that can prevent inadvertent electrical and mechanical engagement of an RJ-11 plug with an RJ-45 jack. 
     Therefore, a receptacle connector is provided for receiving a mating plug and for blocking a relatively smaller second plug from receipt in the receptacle connector. The receptacle connector comprises a housing having a plug-receiving cavity and terminals mounted therein. A deflection member formed of a metal sheet material having a retention section, a ramp surface and a blocking tab is mounted in the housing. The retention section is mounted in a slot and the ramp surface extends into the plug-receiving cavity such that the blocking tab extends laterally from the ramp surface further into the plug-receiving cavity. When the mating plug is inserted into the plug-receiving cavity, the ramp surface is engaged and the blocking tab deflects away from the mating plug thereby allowing insertion of the mating plug. When the second plug is inserted into the plug-receiving cavity, the second plug is stopped by the blocking tabs, thereby preventing insertion of the second plug. 
     Additionally, a modular jack is provided for receiving an RJ-45 plug and blocking an RJ-11 plug from insertion into the modular jack. The modular jack comprises a housing having a plug-receiving cavity and terminals mounted in the housing that project into the plug-receiving cavity. Deflection members are provided on each side of the plug-receiving cavity. Each deflection member has a retention section and a ramp surface arcuately joined. A blocking tab extends transversely from an end of the ramp surface. The retention sections are held in slots of the housing such that the ramp surfaces extend toward the plug-receiving cavity and the blocking tabs are opposed and extend inwardly toward the plug-receiving cavity. The ramp surfaces are disposed such that when the RJ-45 plug is inserted into the plug-receiving cavity, a leading edge of the RJ-45 plug deflects the ramp surface and the blocking tab away from the plug-receiving cavity. Upon insertion of the RJ-11 plug, a leading edge of the RJ-11 plug strikes the blocking tab, thereby preventing insertion thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the present invention will now be described by way of example with reference to the following drawings, wherein: 
     FIG. 1 is an isometric front view of the modular jack of the present invention with a deflection member exploded therefrom; 
     FIG. 2 is a front view of a modular jack of the present invention having a shield member; 
     FIG. 3 is an isometric view of the modular jack of FIG. 2; 
     FIG. 4 is an isometric view of a deflection member of the present invention; 
     FIG. 5 is an isometric front view of a modular jack of the present invention with a deflection member exploded therefrom; 
     FIG. 6 is a front view of a modular jack of the present invention receiving an RJ-45 type plug; 
     FIG. 7 is a cross-sectional side view of a modular jack of the present invention receiving an RJ-45 type plug; 
     FIG. 8 is a cross-sectional side view of the modular jack of FIG. 7 with an RJ-45 type plug fully inserted; 
     FIG. 9 is a front view of a modular jack of the present invention receiving an RJ-11 type plug; 
     FIG. 10 is a cross-sectional side view of a modular jack of the present invention receiving an RJ-11 type plug; 
     FIG. 11 is a cross-sectional rear view of the modular jack shown in FIG. 10 with an RJ-11 type plug being blocked from insertion; 
     FIG. 12 is an isometric view of an alternative deflection member; and 
     FIG. 13 is an isometric front view of an alternative embodiment of modular jack having the alternative deflection members of FIG. 12 loaded therein. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a modular jack  10  of the present invention. The modular jack has a generally box-shaped housing  12  which provides a plug receiving cavity  14  and which carries a plurality of electrical terminals  4 . Electrical terminals  4  extend into cavity  14  and are provided for making electrical contact with a mating plug (not shown). Terminal tails  6  extend from electrical terminals  4  through a bottom wall  18  of housing  12  for connection to external circuitry, such as traces on a printed circuit board. 
     A shield  20  may optionally be provided for modular jack  10  and is shown in FIGS. 2 and 3. Shield  20  comprises a face plate  25  placed along front face  13  of housing  12 . A bottom securing portion  21  is bent from face plate  25  to extend along a forward portion of bottom wall  18  and is secured by lug  11 . Sides  22  are also bent from face plate  25  and extend along sidewalls  16  of housing  12 . Similarly, a top  24  of shield  20  is bent rearwardly from face plate  25  to extend along top wall  17  of housing  12 . Finally, back  26  is bent downwardly from top  24  and is seated against back wall  15  of housing  12 . Back  26  is provided with latching tabs  27  which engage projections on sides  22  to secure shield  20  to housing  12 . The shield shown in FIGS. 2 and 3 is further provided with shielding posts  29  which extend downwardly from sides  22  and are provided for mounting the modular jack to a circuit board (not shown) and/or connecting the shield to an external ground. Outer tabs  28  are punched from sides  22  and top  24  to provide for panel mounting of modular jack  10 . Outer tabs  28  are configured such that modular jack  10  may be inserted into a cut-out of a panel such that outer tabs  28  engage an edge of the cut-out, thereby securing the modular jack within the cut-out and providing a ground path from the shield  20  to the panel (not shown). Inner tabs  23  extend into cavity  14  and further secure the shield  20  to the housing  12  while also improving the snugness of fit of a mating plug (not shown) within the plug receiving cavity  14 . 
     Referring back to FIG. 1, a deflection member  30  is provided in housing  12  on either side of plug receiving cavity  14 . As further shown in FIG. 4, deflection member  30  may be stamped and formed from a metal sheet material to provide a generally arcuate spring member having a retention end  34 , a ramp surface  32  and a stopping tab  36  which projects laterally from an end of ramp surface  32 . Retention protrusions  35  may be provided on deflection member  30  to improve retention of deflection member  30  within housing  12 . Also, insertion tabs  31  may be provided toward the front of deflection member  30  to create a pushing surface for inserting the deflection member into the housing. 
     As shown in FIG. 5, housing  12  is provided with retention slots  40  which extend from an upper portion of front face  13  into housing  12 . A shallow  42  is disposed beneath slot  40  and is recessed from front face  13 . A ledge  44  is also provided which extends along an interior sidewall  41  of housing  12  and runs from front face  13  into plug receiving cavity  14 . Retention slot  40 , shallow  42  and ledge  44  define a receiving area for deflection member  30 . As shown in FIG. 5, deflection member  30  is loaded into housing  12  from front face  13  such that retention end  34  is inserted into retention slot  40  and the stopping tab end of ramp surface  32  rides along ledge  44  until deflection member  30  becomes fully seated in shallow  42 . Insertion tabs  31  provide a pushing surface for inserting deflection member  30  into the housing  12  such that the arcuate spring portion need not be contacted, thereby reducing the likelihood of damage to the deflection member. The deflection members  30  are loaded into the housing  12  such that stopping tabs  36  project inwardly toward plug receiving cavity  14  and are in opposed relationship. Above stopping tabs  36 , a recess  46  is provided in housing  12  to accommodate stopping tabs  36  upon deflection. 
     Operation of the modular jack of the present invention will now be described with reference to FIGS. 6-11. FIG. 6 shows a front view of modular jack  10  as it receives an RJ-45 type modular plug  8 . The RJ-45 type plug  8  very nearly fills all of plug receiving cavity  14  and substantially extends from interior sidewall  41  to opposing interior sidewall  41 . In other words, the width of plug  8  is adequate to snuggly fit within plug receiving cavity  14 . As such, ramp surfaces  32  are engaged by leading edge  9  of plug  8  and are thus deflected upwardly as plug  8  is inserted into plug receiving cavity  14 . As shown in FIG. 7, as plug  8  is inserted into plug receiving cavity  14 , stopping tabs  36  are deflected upwardly and out of the way of leading edge  9  such that stopping tabs  36  do not interfere with insertion of plug  8  into plug receiving cavity  14 . FIG. 8 shows plug  8  fully inserted into plug receiving cavity  14  of modular jack  10  such that deflection member  30  is fully deflected and stopping tabs  36  have been received by recesses  46 . Plug latch  5  is shown in a latched position in which latch edges  7  are received behind latching shoulders  50 . 
     Upon removal of plug  8  from modular jack  10 , deflection member  30  will resile back to its original form, shown in FIGS. 1-3, such that stopping tabs  36  extend inwardly toward plug receiving cavity  14 . 
     FIGS. 9-11 show modular jack  10  in operation blocking an RJ-11 type plug  2 . FIG. 9 shows an identical view to that shown in FIG. 6 with a RJ-11 type plug  2  substituted for the RJ-45 type plug  8 . As shown in FIG. 9, plug  2  does not fully fill plug receiving cavity  14  and does not fully extend from interior sidewall  41  to opposing interior sidewall  41 . In other words, because plug  2  is not as wide as plug  8 , plug receiving cavity  14  is not entirely filled by plug  2 . As such, leading edge  3  of plug  2  does not engage ramp surfaces  32  of deflection member  30 . Instead, leading edge  3  passes between ramp surfaces  32  of deflection members  30  and advances into plug receiving cavity  14  until leading edge  3  strikes an edge  37  of stopping tabs  36 . Stopping tabs  36  and edges  37  are deliberately positioned within plug receiving cavity  14  sufficiently forward in the housing  12  such that plug  2  strikes stopping tabs  36  prior to engagement with contact terminals  4 . Thus, in addition to preventing mechanical engagement, electrical interconnection is also avoided. Furthermore, as shown in FIGS. 10 and 11, plug  2  is stopped by stopping tabs  36  prior to latch  5  engaging latching shoulders  50 , thereby preventing locking of the plug  2  within modular jack  10  and providing indication to the user that proper engagement of the plug with the modular jack has not been achieved. Such indication is provided by the conspicuous absence of an audible “click” typically provided by the engagement of latching edges  7  engaging shoulders  50 , and an absence of the tactile sensation of such a latching action. 
     Referring back to FIG. 4, an advantage of the deflection member  30  of the present invention will now be described. As shown, stopping member  36  projects laterally from an end of ramping surface  32  and is preferably canted slightly upwardly so that it is oriented toward the top wall of housing  12  when loaded in the housing. Although this canting of the stopping tabs is not an absolute requirement of the invention, it is preferable in order to avoid interference between the leading edge  9  of plug  8  and edges  37  of stopping tabs  36  during insertion of plug  8  into plug receiving cavity  14 . By canting the stopping tabs upwardly, interference between leading edge  9  of plug  8  and edges  37  of stopping tabs  36  is assuredly avoided. 
     FIGS. 12 and 13 show an alternative embodiment of the present invention. The alternative deflection member  60  is shown having ramping surface  62  which extends to stopping tabs  66  which again are shown projecting laterally from an end of ramping surface  62  and canted with respect to the end of ramping surface  62 . A retention end  64  is also provided on deflection members  60  and an auxiliary retention section  63  is disposed at an angle to retention end  64 . Protrusions  65  are located along edges of retention end  64  and auxiliary retention section  63  to firmly secure deflection member  62  in an interference fit within the housing of the modular jack. FIG. 13 shows a modified housing  12  having retention slots  80  and  81 , shallow  82  and ledge  84  which define a receiving area for deflection member  60 . Retention slot  81  is disposed at an angle to retention slot  80  and is configured to receive auxiliary retention section  63  of deflection member  60 . Similar to the deflection member  30  described above, deflection member  60  is front loaded into housing  12  such that retention end  64  is received in retention slot  80 , auxiliary retention section  63  is received in retention slot  81 , and an end of ramping surface  62  lies along ledge  84 . Upon complete insertion of deflection member  60  into housing  12 , deflection member  60  becomes fully seated in shallow  82  and protrusions  65  achieve an interference fit within retention slots  80  and  81 . By providing a deflection member with an auxiliary retention section set at an angle to a retention end, further security of the deflection member within the housing may be achieved. 
     The following advantages of the present invention should be apparent from the foregoing disclosure. By providing a modular jack having deflection members with stopping tabs, improper insertion of an RJ-11 type plug into an RJ-45 type jack is avoided. A stamped and formed deflection member provides a low-cost, easily manufacturable device to prevent damage to the RJ-45 type jack. In particular, the simple arcuate-shaped deflection member disclosed herein requires minimal forming to achieve its desired function. Furthermore, by disposing the deflection members in portions of the housing on either side of the latching shoulders  50 , sections of the housing which were previously unused in standard modular jacks may now be efficiently used to retain the deflection members. Therefor, the overall profile of the modular jack does not increase with the addition of deflection members. Canting of the stopping tabs prevents the leading edge of an RJ-45 plug from hanging up on the stopping tabs, thereby providing smooth reception of an RJ-45 plug while still preventing insertion of an RJ-11 plug. 
     In addition, in the rare event that a deflection member is damaged, either or both deflection members may be easily removed and replaced. Also, because minimal modification is made to the modular jack housing to provide deflection member receiving areas, the same housing may also be used in applications where deflection members are unnecessary. In other words, modular jacks may be supplied having the same housing but not having deflection members loaded therein. In this manner, tooling and inventory may be consolidated. 
     It should be apparent that while RJ-11 and RJ-45 type modular jacks and plugs have been described herein, the principles of the present invention are easily extendable to other receptacle connectors having similarly shaped mating plugs. 
     The present invention and many of its attendant advantages will be understood from the foregoing description. It is apparent that changes may be made in the form, construction, and arrangement of parts thereof without departing from the spirit of the invention, or sacrificing all of its material advantages. Thus, while several embodiments of the invention have been disclosed, it is to be understood that the invention is not strictly limited to those embodiments but may be otherwise variously embodied and practiced within the scope of the following appended claims.