Abstract:
An electrical connection box for wall mounting provides a recessed external plug for receiving or transmitting power to electronic components. The connection box is configured to receive a variety of signal connection modules for interconnecting associated audio/visual electronics such as DVD players, displays and the like in adjacent apertures. The signal connection modules are inserted or extracted from the face of the connection box; replacing blanking plates, and is optionally recessed from the face of the box into the wall cut-out. The configuration and mating features of the box and modules also provides for a common and isolated ground reference for surge protection of the connected components.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a division of and claim priority to U.S. application Ser. No. 10/788,073, filed Feb. 25, 2004, for a “Modular Signal and Power Connection Device”, which is incorporated herein by reference. 
     
    
     BACKGROUND OF INVENTION  
       [0002]     The current invention relations to wall mounted electrical junction box for power and low voltage signal connections of related electronic components.  
         [0003]     Electronic components used in audiovisual systems are subject to damage from electrical power surges. Numerous technologies and designs exist for either disconnecting equipment from such damaging conditions, or shunting the power to a ground connection via a nonlinear component. However, effective implementation of the schemes and designs requires interconnected components to be connected with a single ground source.  
         [0004]     Moreover, typical audiovisual systems utilizes multiple powered components, which are interconnected to receive and transmit relatively low voltage signals. To the extent that some of these components are physically separated from other components, for example the visual display unit for home theater system might be located across the room from a cabinet containing the DVD player or high-definition television encoder, low voltage signal wire cabling is preferably routed through walls to avoid physical hazards as well as a cluttered appearance.  
         [0005]     Although power and signal cables might be physically separated outside of the interconnected components, over voltage conditions, arising from unstable line voltage, or lightning strikes, can propagate through multiple components in the absence of an appropriately designed system. Accordingly, there exists a need for connection devices that can facilitate the installation of multiple, physically separated audiovisual components of them in a manner that readily provides necessary surge protection.  
         [0006]     Their exists a further need for connection devices that can be readily installed in walls and accommodate a wide variety of low voltage signal connectors to might be encountered when combining various types of displays, video processors, audio equipment, data communication equipment and/or computers.  
         [0007]     There remains a further need for such a connection devices that permits various audiovisual components to be mounted nearly flush to the structural walls or other architectural features yet the same time accommodate a variety of connected plugs sizes.  
       SUMMARY OF INVENTION  
       [0008]     The above and other objectives of the invention is satisfied in a first aspect by providing a connection box for wall installation that has a front face that covers substantially all of a cut-out in a wall. Within the front face is a first cavity extending inward to receive a power cord plug at a socket disposed at the bottom of the cavity, for example, a power plug connector having line, neutral and ground terminals. The corresponding socket has input terminal for L, N and G disposed behind the socket an aperture for receiving at least one of a blanking plate &amp; a signal connection module, two or more walls disposed on opposing sides of the aperture and extending inward face. Walls in electrical contact connection with at least one of the ground input or output terminal of the socket. Thus, power plugs can be recessed into the connection box, permitting a nearly flush mounting of the associated A/V components.  
         [0009]     In a second aspect of the invention, a signal connection module or blanking plate is inserted into the aperture cover the remainder of the aperture, avoiding an opening between the wall interior and the room. The module or blanking plate is supported by the walls on opposing sides of the apertures.  
         [0010]     In another aspect of the invention, the signal connection module is dimensioned for insertion into the aperture within the front face of the aforementioned connection box. Accordingly, the signal connection module has a substantially flush front face with one or more sockets for receiving corresponding signal plugs from the associated A/V equipment. The signal module also has at least two adjacent sides connected to the front face of the module that fit closely between corresponding walls extending inward from the aperture in the connection box. Low voltage signal output connectors emerging rearward from behind the front face, corresponding to the multiple low voltage signal input sockets disposed on front face of the module. The two or opposing sides of the module are in electrical connection with ground shield wires associated with the low voltage signal wires that connect the input and output connectors in the module, providing electrical continuity to a common ground associated with the power socket ground wire via physical contact with wall associated with the aperture in the connection box. Electrical continuity is maintained over a range of alternative displacement of the signal module with the connection box aperture, thus both the signal and power plugs can be recessed into the connection box, permitting a nearly flush mounting of the associated A/V component.  
         [0011]     As will be further described, other aspects of the invention include mechanical features for grasping, moving and latching the signal module at variable position rearward from the front face of the connection box, as well as connection boxes configured to receive an array of signal connection modules, with or without blanking plates.  
         [0012]     The above and other objects, effects, features, and advantages of the present invention will become more apparent from the following description of the embodiments thereof taken in conjunction with the accompanying drawings 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0013]      FIG. 1  is an exploded perspective view showing the connection box and signal connection module.  
         [0014]      FIG. 2  is a schematic electric circuit for the connection box and signal connection module  
         [0015]      FIG. 3A  is an elevation of the connection box taken through the wall bisecting the signal connection module; whereas  FIG. 3B  is an exterior elevation as observed from the room.  
         [0016]      FIG. 4  is an elevation of an alternative embodiment of the connection box including an installed signal module as observed from the room. 
     
    
     DETAILED DESCRIPTION  
       [0017]      FIG. 1  illustrates in an exploded perspective view the connection box  100  and signal connection module  150  for use therewith. Connection box  100  has a front face  110  for mounting substantially flush with a surface, generally a room interior wall. Although signal connection module  150  is normally inserted into the connection box from the front face  110  side of connection box, it is shown behind the front face for illustration purposes. Connection box  100  has a first cavity  120  that extends inward, that is toward the interior of the wall, from the front face  110  for receiving a power connector in socket  130  disposed at the bottom of the cavity  130 . Accordingly, socket  120  has electrically isolated input sockets for receiving plug prongs for connecting the corresponding line, neutral and ground wires thereto. Although not shown in this Figure it should be understood that connection box  100  also includes corresponding line, neutral and ground connection terminals for receiving bare conductor wire mounted behind the socket. The aforementioned components are however illustrated in a schematic electrical circuit diagram of  FIG. 2 . The front face  110  of connection box  100  also includes at least one aperture  140  for receiving either a blanking plate  105  (shown in  FIG. 4 ) or a signal connection module  150 . Signal connection module  150  is inserted into aperture  140  and thus supported by two or more sidewalls,  145   a  and  145   a ′ that are disposed on opposing sides of the aperture  140  to extend inward from the front face  110 . In this embodiment, two additional side walls  145   b  and  145   b ′ connect with walls  145   a  and  145   a ′ to form a box like enclosure. Further details of the construction and operation of the signal module  150  are described below and in particular with reference to  FIGS. 3 and 4 .  
         [0018]     It should be appreciated that power socket  120  is optionally selected to receive either straight prong connector plug, as illustrated, or a twist lock plug, and can be any plug type, particularly when it is desired to limit the connection to a single electronic component with a mating power cord connector, such as a power conditioning module. Connection box  100  also has a plurality of holes at the periphery of face  120  that are disposed to align with convention terminal box, or J-Box, located behind the wall, the terminal box being generally required by electrical and building codes. Thus, screws inserted in these holes secure physical stability of connection box  100  with respect to the wall or other planar surface. In the most preferred embodiment, connection box  100  extends like a flange about the periphery of the front face  120 . Such a flange extension conceals the J-box, but is more preferably limited in outer dimensions for receiving a decorative cover plate. The outer or peripheral dimensions of front face  110  are slightly small than a conventional decorative wall plate, should a user or consumer wish to cover a portion of face  120  for aesthetic reasons.  
         [0019]     As will be further described with reference to  FIGS. 2, 3  and  4 , at least one of the sidewalls  145   a / 145   a ′ and  145   b / 145   b ′ of connection box  100  contact and provide electrical continuity with at least one of the ground input or output terminal of socket  130 .  
         [0020]     Signal connection module  150  has a front face  160  and at least two opposing sides  165   a  and  165   a ′ parallel to each other and disposed perpendicular to the front face  160 . Multiple low voltage signal input sockets  170   a, b, c, d  and  e  are also disposed on front face  160 . Corresponding multiple low voltage signal output connectors  180   a, b, c, d  and  e  emerge rearward from behind the front face  160  having separate parallel to corresponding to input sockets  170   a - e . Further, in this preferred embodiments shown, output connectors  180   a - e  are separated from the rearward portion of signal connection module  150  by a lengths of signal wire cable  181   a  to  181   e . The signal wire cable extends output connectors  180   a - e  away from signal connection module  150  to enable the convenient installation of signal wire from the room after connection box  100  is installed. That is, signal connection module  150  can be inserted from the room side of connection box  150 . Accordingly, it should be appreciated that the signal connection module are readily reconfigured after an initial installation, should the user or consumer wish to deploy alternative A/V sources. The signal cables  181   a  to  181   e  provide slack, and hence effective strain release, for cable running behind the wall when the signal connection module is installed or reconfigured Further, the signal wire cable  181   a  to  181   e  enable the use of larger output sockets than might not fit on the front face  160  of signal connection module  150 , but would still fit in the space behind or within the wall. Further, as is more fully described with respect to  FIG. 3 , additional mating components associated with the sides of signal connection module  150  and connection box  100  permit signal connection module  150  to be offset at multiple positions within aperture  140 . Such features include a spring-loaded ball  166 , which is mounted within signal connection module  150  and extends partially through a hole in the upper surface  165   a  of connection module  150 . As the associated spring urges ball  166  into the hole and a corresponding orifice on the opposing face of the aperture wall  145   a , the signal connection module  150  is secured in aperture  140 , but still readily removable by the application of sufficient lateral force to overcome the retaining force of the associated spring. Accordingly, on moving the signal connection module laterally within aperture  140 , ball  166  is displaced back into the signal module, out of contact with the opposing face of the aperture wall. Thus, the placement of multiple mating orifices on the same opposing face permits a variable adjustment of the recess of the front face  160  of signal module  150  behind the face  110  of connection box  100 , as further described with respect to  FIGS. 3 and 4  below. Referring to the schematic electrical circuit of  FIG. 2 , it should be apparent that the two opposing sides  160  of signal connection module  150  make electrical contact connection with ground shield wires associated with 2 or more of the signal i/o sockets  170 / 180 . Thus at least one of the sidewalls  165   a/a′,b/b′  makes electrical contact with one of walls  145   a/a′,b/b′  associated with the aperture in the connection box  100  to provide a common ground connection between the circuit sub modules in the Figure, However, It should be further appreciated that the electrical continuity between the respective ground wires in the signal module and the connection box is insured by the springs urging of ball  166  into contact with both the signal module and the connection box components.  
         [0021]     In a more preferred embodiment, at least one of the sides  165   b  of signal connection module  150  has a recessed flat panel,  165   c , for receiving a label for displaying printed matter such as product identification, installation instructions and the like. Placing the printed labels within recessed panel  165   c  avoids the wear or degradation of the label on the otherwise contacting face of the sides walls  145   b  of aperture  140  in connection box  100 .  
         [0022]     According, the front face  160  of signal connection module  150  optionally includes any variety and combination input sockets and output sockets or output plugs, such as RCA, VGA, Co-axial cable, phone, data communications, Ethernet type, and the like. It should be further appreciated that extension cable  181   a - e  can be of any length, and can be eliminated depending on the need for the optional adjustability of signal connection module  150  within aperture  140 , the skill of the installer, or the intended permanence of the installation.  
         [0023]     The electrical schematics of circuit  200  in  FIG. 2  further illustrates other aspects of the invention wherein optional signal protection, power protection (collectively SP) or power conditioning components are interconnected via a common ground connection between the signal connection circuit module  230  and the ground wire of socket  130  of the power circuit module  210 . It should be appreciated that the actual circuit protective function in signal protector module  210  and an AC protector module  220  is accomplished by limiting voltage differences between wires passing to the protected A/V equipment (PE) to levels safe for the equipment. If the allowable voltage difference between two terminals of the equipment is exceeded, either an insulating path isolating the connections will flash over, or a component connecting the two terminals will overheat and be damaged. Since both the number of terminal connections and the allowable voltage differences vary widely from one piece of equipment to another, surge protectors must be specially designed to meet the needs of the PE. Broadly, the connection to PE can be defined as being either “Power” (e.g., 120VAC in many cases), or “signal” connections. Power connections provide for the power supplies for the PE, as well as powering AC-powered equipment such as monitors and display, as well as DVD players, amplifiers and the like. Signal connections are generally of lower voltage and current than power connections, and are used to transmit information and control among different pieces of the PE. Typically, but not always, the AC connections will withstand larger voltages than the signal connections.  
         [0024]     Thus, in  FIG. 2 , the separate socket terminal on the face power plug  130  sockets, denoted as line voltage (L)  241 , Ground (G)  242  and neutral (N)  243 , are connected by wire  211 ,  222  and  223  to respective rear connection terminals  221 ,  222 , and  223 . The rear connection terminals are for securing conventional interior power wiring, per local electrical and building codes. Ground wire  213  is represented as connecting to a common ground to emphasize the electrical continuity between the signal connection module and connection box, shown as circuit trace  250 . The signal connection module  150  preferably has an over-voltage protection circuit  230 , which is disposed in serial connection between each of the signal paths  270   a  through  e  connecting the isolated I/O terminals  170 / 180   a - b . Note that additional I/O terminals, such as those described with respect to  FIG. 1  are omitted merely to simplify the diagram, the number and type in each Figure being exemplary and not intended to limit the scope of the invention.  
         [0025]     Each pair of input connectors shown in this diagram,  270   a  and  270   b , comprises an outer conductor, usually signal ground, which flows to respective output terminal  180   a  and  180   b  over signal wires  271   a  and  272   a . Central socket conducts of sockets  170  and  170   b  connect to the center pin of output thermals  180   a  and  180   b  via signal wires  271   b  and  272   b.    
         [0026]     Signal wire lines  271   a/b  and  272   a/b  are in fact preferably formed on a printed circuit board (PCB) to facilitate interconnection with the protection circuitry. Thus, each individual signal wire line in circuit  230  is in a parallel connection with a protected path to ground trace  250  via a pair of isolating diodes, that is signal wire  272   b  is isolated from both a unidirectional voltage limiting device  261  and diode  260   b , which lead to ground, by diode pair  265   a  and  265   b . Whereas is signal wire  272   b  is isolated from unidirectional voltage limiting device  261  and diode  260   b  by diode pair  264   a  and  264   b , and likewise for signal wire  271   b  (diode pair  263   a/b ) and signal wire  271   a  (diode pair  262   a/b .) Thus, the diode pairs limit any excess current from the signal wires to flow clockwise to device  261 , which acts in the reverse bias condition to set the protecting or clamp voltage for the protected A/V equipment. Thus, in this preferred embodiment rectifier Diodes  260   a  and  260   b  direct current that is shunted from the signal lines upon an over voltage conditions, as defined by the voltage threshold of the device  261 , such that the shunted current will flow in the clockwise direction to trace  250  and then to ground. Unidirectional voltage limiting device  262  is preferably a silicon avalanche diode (SAD),  261  also isolates the signal module traces  270   a  and  270   b  from high currents that could otherwise be conducted through diode  260   a , upon high voltages surges occurring within power circuit  210 .  
         [0027]     It should be appreciated that  FIG. 2  is not intended as a limiting examples, as further surge protection circuit are optionally provided in circuit sub module  210  in a parallel connect to ground for the L, N and G lines of the power socket, or as a serial connected circuit for filtering out AC line noise.  
         [0028]      FIG. 3  illustrates further the mechanical features of a preferred embodiment of the invention, shown in elevation taken through an installed signal connection module taken orthogonal to the wall (represented by segments  390  and  390 ′ above and below the signal connection box respectively.) Connection box aperture walls  145   a  has indentation(s) for receiving a mating feature disposed on the sidewalls of the signal module. Note that in this embodiment, signal connection module  150 , while slideable within aperture  140  is disposed at the intermediate of three positions, being removeably secured by the displacement of ball  166  into the second of three hemispherical depressions that extend upward into wall  145   a  of aperture  140 . Thus, the placement of the hemispherical depressions defines a plurality of latched positions for signal module  150  within aperture  140 . A spring  367  is fixed at one end to a portion of connection module  150  with the opposing end extending upward to urge ball  166  out of a circular hole formed in the upper surface  165   a  of signal connection module  150 . According on pulling or pushing module  150  in the lateral direction the force of spring  167  is overcome such that ball  166  can then can secure the connection module in an alternative position by engaging either of the adjacent hemispheres,  353  and  351 . As ball  166  is spring loaded, it provides for a secure electrical connection from connection box  100  to signal module  150 . The spring is preferably supported within the bore of a threaded shaft  367 , the shaft bottom being either closed, or having a diameter small than the diameter of spring  368 . The threaded shaft  367  is then inserted into a nut or other component with mating thread on the inside of wall  165   a  box below the hole that limits the spring-loaded ball from extending there through. It should be appreciated that alternative embodiments to a latching function supplied by the spring-loaded ball include other types of spring members, possibly without a ball, but direct spring contact. Further embodiments that perform substantially the same function include, without limitation, plural mating feature on each signal connection module, such as holes or hemispherical depressions, with a spring-loaded ball or hemisphere extending from the aperture sidewall. In this alternative embodiment, the ball or hemisphere would retracts into the aperture wall s signal connection module or blanking plate is translated within aperture  140  of connection box  100 .  
         [0029]     The ball  266  and mating features in aperture wall  145   a  or a 45   b  are preferably offset to one side of the center line of signal connection module  150  to provide maximum space for signal connection sockets centered on the front face  160  of signal connection module  150 , as well as leaving the maximum space and height for a PC board  380  and associated surge protection components.  
         [0030]      FIG. 3  also illustrates one embodiment of a mechanical feature suitable for grasping and either sliding or removing the signal connection module from the room side. A grip-receiving member  377  is preferably formed by providing an adjacent pair of slits to define a narrow strip of metal. The narrow strip of metal is then deformed outward from face  160  to form grip-receiving member  377  as an isthmus that extends several millimeters outward to the room side. Accordingly, a gripping tool can be inserted at the slit edges to reach behind and grip member  377  from the room side of the connection box. It should be appreciated that grip receiving member  377  is alternatively formed as an inward protruding indentation formed about slits in the front face. In the latter embodiment, the gap between the slits and the punched in isthmus provide access to insert an alternative tool behind the back of the front face to grasp and remove the signal connection module there from. In either case, a preferred form of tool is essentially a plier with suitable dimensioned tips to grasp one or more of grip receiving member  377  and retract the signal connection module  150  back into the room. Further, a pair of grip receiving members  377  and  377 ′ are preferably disposed offset from the centerline of signal connection module such that they do not interfere with the placement of signal sockets on the front face, or a printed circuit board (PCB)  380  mounted within the signal connection module. Further, the Connection box  150  preferably includes one or more backstops  168  that extend laterally at the rearward end of apertures walls  145   a  or  145   b  and thus preclude signal connection module  150  from accidentally being pushed through aperture  140  and falling behind the wall  377 .  
         [0031]     In addition, a plurality of a sequence of hemispherical depressions akin to  351 ,  352  and  353  are preferably disposed at equal offset from the vertical center line through aperture  140 , on the bottom wall  165   b , but omitted for clarity, for removable engagement of an additional spring loaded ball (also omitted for clarity) disposed at the bottom surface  165   a ′ of signal connection module  150 .  
         [0032]      FIG. 4  further illustrates the mechanical features of an alternative embodiments of the invention. Multiple signal modules and blanking plates are illustrated in an elevation of connection box  400  as viewed from the room side. Thus, connection box  400  has a wider aperture  440  than aperture  140  in  FIG. 1 , to accommodate three signal connection modules. In this Figure, signal connection module  450  and  451  are disposed on opposing sides of blanking plate  440 . Each of the signal module and the blanking place has one or more of substantially identical grip member  377   a, b  or  c  disposed on their front face. Further, each of signal connection modules  451  and  450  deploy distinctly different types and combinations of low voltage signal sockets. That is signal connection module  451  includes a substantially rectangular multi-pin connector terminal  470   a  and a round connector terminal  471   a ′. It should be appreciated that a multi-pin connector optionally replaces any round connector illustrated, which is round or substantially rectangular. Further, any of the output terminals on the rear side of the signal connection module  150 , such as  180   a - e  in  FIG. 1 , are optionally configured as male or female connections, screw or spring loaded terminals for receiving bare conductor or insulation displacement style terminals, and the like.  
         [0033]     Also illustrated in further detail in  FIG. 4  is a blanking plate  105  having the same exterior dimensions as signal connection module  150 , with a substantially planar front face, and a ball  166 ′, or other latching member, extending from face  165   a ′ to provide the same adjustable function as ball  166  on signal connection module  150 . Blanking plate  105  need not include additional side faces, provided that face  165   b , and a corresponding face at the bottom of blanking plate  105 , or other mechanical features, provide sufficient structural rigidity. Similarly, in the signal connection module  150  side faces  165   b  and opposing side face  165   b ′ (not shown) are also optional, being provided to house and protect electrical component and terminal within signal connection module  150 .  
         [0034]     It should be appreciated that the exemplary protection circuit shown in  FIG. 2  is not intended as limiting examples, as further surge protection circuitry is optionally provided on a PCB adjacent but behind the power socket  130 , being operative to shunt current from high voltage transients in the power lines. In other selected embodiments, a noise filtering circuit is optionally provided on a PCB adjacent but behind the power socket  130 .  
         [0035]     While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be within the spirit and scope of the invention as defined by the appended claims.