Abstract:
An electronics housing enabled to compensate for the accumulation of dimensional tolerances to enable reliable connection between one or more connectors mounted to internal electronic components and external connectors from one or more external devices. An alignment plate is provided that adapts an aperture in the housing to the connectors. The alignment plate is adapted to account for tolerance accumulation by being positional within the housing while substantially covering the space between the connectors and the housing aperture. The alignment plate in cooperation with an EMI a shield provides electromagnetic shielding about the connectors.

Description:
FIELD OF THE INVENTION 
     The present invention relates to housings containing electronic components having connectors for communication with external devices and, more particularly to a housing which enables connectors mounted on internal components to reliably engage the connectors of external devices in the presence of assembly and manufacturing dimensional tolerance accumulation. 
     BACKGROUND OF INVENTION 
     It is well known that in the image projection, communication, navigation, computer and like industries manufacturing electronic systems, that the electronic systems are made up of a plurality of subsystems with one or more of the subsystems being assigned to a particular printed circuit board (PC board). The PC board is normally in a housing. It is required that the PC board be received in the housing in a manner enabling the PC board to be removed from the housing for maintenance, repair and/or replacement. Mounted on the PC board are one or more electrical connectors, plugs, or receptacles that are adapted to couple with external mating connectors, plugs or receptacles for power and/or signal paths between the PC board inside the housing and external devices. 
     The electronics housing comprises a bezel having connector apertures. The bezel is likened to a frame that surrounds the connectors of an internal electronic device. The PC board is mounted within the housing strategic to the bezel apertures wherein the PC board connectors are positioned behind, flush with, or protruding from the apertures. An external device can therefore access a connector with a mating connector either externally if the connector protrudes through the aperture or by passing the mating connector though the aperture to mate with the connector within. 
     It is well known in the art that the manufacture and assembly dimensional tolerances provided by the electronic system design requires very precise matching of the housing mounting apparatus with the PC board attachment. Further, precise manufacture of the electrical connector arrangement on the PC board is required for proper alignment of the connectors with the apertures in the bezel. This precise matching of components to the housing/bezel adds to the cost of the electronic system. 
     For practical reasons known to those in the art of manufacture and assembly, all of the components of the electronic system have associated with them a dimensional tolerance. Even with precise manufacturing processes of the PC board and the housing together with the connector mounting arrangement, the accumulation of dimensional tolerances can lead to a misalignment of assembled components. In particular, the accumulation of tolerances can result in a misalignment between the PC mounted connectors and their corresponding bezel apertures. Connector/aperture misalignment can prevent reliable connection or preclude connection at all between the connector on the PC board and the connector of the external device. Significant disassembly and rework of the components of the electronic system to remedy this misalignment is labor intensive and not conducive to maintaining manufacturing efficiencies. 
     There is a need for apparatus and methods to account for the accumulation of manufacture and assembly tolerances and to accommodate those tolerances to provide proper alignment of the PC board connectors and the access apertures in the housing bezel. 
     SUMMARY OF INVENTION 
     An electronics housing enabled to compensate for the accumulation of dimensional tolerances to enable reliable connection between one or more connectors mounted to internal electronic components and external connectors from one or more external devices. An alignment plate is provided that adapts an aperture in the housing to the connectors. The alignment plate is adapted to account for tolerance accumulation by being positional within the housing while substantially covering the space between the connectors and the housing aperture. The alignment plate in cooperation with an EMI shield provides electromagnetic shielding about the connectors. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is a side perspective view of an electrical system in accordance with an embodiment of the invention; 
     FIG. 2 is a view of a PC board with connectors mounted thereon: 
     FIG. 3 is a view of an alignment plate in accordance with an embodiment of the invention; 
     FIG. 4 is a view of the bezel in accordance with an embodiment of the invention; 
     FIG. 5 is a view of the bezel and alignment plate in accordance with an embodiment of the invention; 
     FIG. 6 is a view of the alignment plate in accordance with an embodiment the invention; 
     FIG. 7 is a view of the alignment plate in accordance with another embodiment the invention; 
     FIG. 8 is a view of an electromagnetic shield in accordance with an embodiment the invention: 
     FIG. 9 is a view of the electromagnetic shied in accordance with the embodiment shown in FIG. 8; 
     FIG. 10 is a view of an electromagnetic shield in accordance with another embodiment the invention. 
    
    
     DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings which form a part hereof wherein like numerals designate like parts throughout, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents. 
     The following description will be directed to an adjustable alignment plate as it relates to an arrangement of electrical connectors on a printed circuit (PC) board and their relationship with a housing or a housing including a bezel. However, it is to be understood that other electrical components mounted inside a housing requiring connection with external sources via one or more connectors can also benefit from the adjustable alignment plate of the present invention. 
     FIG. 1 is a side perspective view of an electrical system  10  in accordance with an embodiment of the invention. The electrical system  10  comprises a housing  20  containing an electrical component mounted within. The electrical component comprises a protruding connector  14 , a flush-mounted connector  15 , and a jack connector  18 , all of which are adapted to accept mating connectors from devices external to the housing  20 . The three connectors  14 , 15 , 18  referred to herein are examples of different types of connectors known in the art. They are used here for illustrative purposes only and not intended to limit the scope of the invention. 
     The housing  20  further comprises a bezel  30  having a bezel aperture  32  that provides accessibility by external mating connectors. The housing  20  further comprises an alignment plate  40 . The alignment plate  40  comprises a first aperture  16  adapted to closely conform to the external shape of the protruding connector  16 . A second aperture  17  and third aperture  19  are adapted to provide access to the flush-mounted connector  15  and the jack connector  18 , respectively, by external connectors. 
     FIG. 2 illustrates the PC board  12  with the corresponding connectors  14 , 15 , 18  mounted thereto. The manufacture and assembly tolerance of the mounted connectors  14 , 15 , 18  with respect to the PC board  12  is commonly very small; a benefit derived by the exacting process involved in manufacturing PC boards. Therefore, the manufacture tolerance of the alignment plate  40  with corresponding apertures  14 , 15 , 18  can be very small, the benefit of which will be discussed below. 
     FIG. 3 illustrates the alignment plate  40  comprising the first, second and third apertures  16 , 17 , 19 . The alignment plate  40  is positioned between the PC board  12  and the bezel  30 . The alignment plate  40  is adapted to adjust or shift with respect to the bezel  30  to accommodate for the accumulation of manufacture and assembly tolerances while effectively covering the space between the bezel aperture  32  and the connectors  14 , 15 , 18 . 
     FIG. 4 illustrates the inside view of the bezel  30 . The bezel  30  further comprises a pair of first tabs  34  and a pair of second tabs  35 . The first tabs  34  and second tabs  35  extend a distance from a bezel aperture lip  33  at least equal to the thickness of the alignment plate  40 . The first tabs  34  are spaced closer to each other than the second tabs  35 , the significance to be described below. 
     FIG. 5 illustrates the inside of the bezel  30  coupled with the alignment plate  40 . When assembled, the alignment plate  40  is held between the bezel aperture lip  33  and the first tabs  34  and second tabs  35 . 
     The alignment plate  40  comprises a pair of first notches  36  and a pair of second notches  37  as shown in FIGS. 3 and 5. The pair of first notches  36  and the pair of second notches  37  are in complimentary relationship with the pair of first tabs  34  and second tabs  35 . The alignment plate  40  is coupled to the bezel  30  by aligning the first notches  36  with the first tabs  34  and the second notches  37  with the second tabs  35 . Once aligned, the alignment plate  40  is placed against the bezel aperture lip  33  with the tabs  34 , 35  passing through the notches  36 ,  37 . The alignment plate  40  is subsequently shifted longitudinally, as indicated by arrow  48 , with respect to the bezel  30  such that the notches  36 , 37  and tabs  34 , 35  are no longer aligned and the alignment plate  40  is held between the bezel aperture lip  33  and the tabs  34 , 35 . 
     The first tabs  34  are spaced closer to each other than the second tabs  35  to ensure that the alignment plate  40  is coupled to the bezel  30  in the correct orientation. This provides an added measure of safety that prevents the alignment plate  40  from being assembled to the bezel  30  in a wrong orientation. If the alignment plate  40  were to be turned around or flipped, the first notches  36  and second notches  37  would not be in alignment with the first tabs  34  and the second tabs  35 , respectively. In other embodiments in accordance with the invention, the tabs  34 , 35  and notches  36 , 37  are located in other arrangements suitable for the particular purpose. 
     In the embodiment of FIG. 5, the first tabs  34  and the second tabs  35  are spaced such that they do not restrict the movement of the alignment plate  40  in the longitudinal direction as indicated by arrow  48 . In this way, the alignment plate  40  can accommodate dimensional tolerance accumulation in the longitudinal dimension. In another embodiment of the invention, not shown, the first tabs  34  and the second tabs  35  are spaced to allow the alignment plate  40  to not only move in the longitudinal direction but also to a limited degree, in the transverse direction, as indicated by arrow  49 . In this way, the alignment plate  40  can accommodate dimensional tolerance accumulation in both the longitudinal and transverse dimension 
     As shown in FIG. 1, the protruding connector  14  protrudes through the first aperture  16 , which is substantially conformal to the exterior shape of the protruding connector  14 . In effect, when assembled, the protruding connector  14  acts to align the alignment plate  40  with the other connectors  15 , 15 , 18  on the PC board  12 . 
     FIG. 6 illustrates an embodiment in accordance with the present invention of an alignment plate  40  having an alignment rib  44 . The alignment rib  44  is adapted to abut one of the connectors in order to assist in aligning the alignment plate  40  with the connectors on the PC board  12 . Referring to FIG. 2, the flush connector  15  has a square body portion  16  having two perpendicular sides  11 . In the embodiment of the alignment plate  40  illustrated in FIG. 6, the body portion  16  can be used to align the alignment plate  40  with respect to the connectors  14 , 15 , 18  on the PC board  12 . The alignment rib  44  is shaped to conform to the two perpendicular sides  11  of the connector body  16 . The contact between the body portion  16  and the rib  44  aligns the alignment plate  40  with the connectors  14 , 15 , 18  in both the transverse and longitudinal direction. This registration of the alignment rib  44  with the connector  15  assists in accurately locating the alignment plate  40  with all the attached connectors  14 , 15 , 18 . This embodiment of the alignment plate  40  is beneficial, for example, but not limited to, electrical systems having a protruding connector  14 , as well as electrical systems wherein there are no protruding connectors on the PC board  12 . 
     In another embodiment in accordance with the present invention, illustrated in FIG. 7, alignment plate  40  comprises a raised boss  46  that surrounds and conforms to the aperture  19  (hidden from view, see FIG.  3 ). The raised boss  46  can be beneficial in a number of ways. In one embodiment, not shown, the raised boss  46  can be used as an alignment aid wherein the raised boss  46  is adapted to slide over a body portion of a connector. In another embodiment, not shown, wherein the connector on the PC board  12  is set back from the other connectors, the raised boss  46  is used as an extension of the alignment plate  40  wherein the length of the raised boss  46  corresponds to the setback distance of the connector. Additionally, in this embodiment, the raised boss  46  can be used to guide an external connector into the connector on the PC board  12 . 
     Electromagnetic interference (EMI) is a persistent problem in electrical systems and in particular near the interface between internal and external connectors. It is beneficial to limit the EMI exiting or entering the electronic system, especially through apertures and gaps in the housing. 
     FIG. 8 illustrates an EMI shield  50  in accordance with an embodiment of the present invention. The EMI shield  50  comprises a shield aperture  52  sized to enable the protruding connector  14  to project therethrough. The EMI shield  50  is advanced over the protruding connector  14 . The EMI shield  50  has flexible fingers  54  which are adapted to make contact with the bezel  30 , and therefore the housing  20 , to effect an electrical ground, as shown in FIG.  9 . The alignment plate  40  is assembled over the connectors  14 , 15 , 18  and placed in electrical contact with the EMI shield  50 . Contact between the alignment plate  40  and the EMI shield  50  ensures that an electrical connection between the two is made such that the alignment plate  40  may further act as an EMI shield  50 . The alignment plate  40  will therefore provide EMI shielding for the remainder of the connectors  15 , 18  over which it is placed. The small manufacture tolerance of the apertures  16 , 17 , 19  in the alignment plate  40  permitted by application of this invention further improves the effectiveness of the EMI shielding as spaces between connectors  14 , 15 , 18  and the shielding is greatly reduced. The alignment plate  40 , when used in cooperation with an EMI shield  50 , effectively reduces EMI around the area adjacent the connectors  14 , 15 , 18 . 
     FIG. 10 illustrates an EMI shield  60  in accordance with another embodiment of the invention. The EMI shield  60  in this embodiment comprises apertures corresponding to all the connectors  14 , 15 , 18  on the PC board  12 . The EMI shield  60 , therefor, provides direct EMI shielding for all the connectors  14 , 15 , 18 . The edges  64  of the EMI shield  50  are in electrical contact with the bezel  30  to effect EMI shielding. 
     Although specific embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations calculated to achieve the same purposes may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. Those with skill in the art will readily appreciate that the present invention may be implemented in a very wide variety of embodiments. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.