Patent Publication Number: US-6991485-B2

Title: Snap fit modular electrical distribution block

Description:
This is a continuation of application Ser. No. 10/303,250 filed Nov. 25, 2002 now U.S. Pat. No. 6,835,081. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to modular electrical distribution systems, and, more particularly, to modular electrical distribution blocks used with distribution harnesses in a modular furniture environment. 
     2. Description of the Related Art 
     Distribution harnesses are known within a modular furniture environment to distribute electrical utilities within and to various modular wall panels. A typical distribution harness may include at least two end connectors, each end connector connected to a channel enclosing at least one conductor. The conductors are interconnected via an electrical distribution block which has a plurality of terminals corresponding to and interconnecting the conductors. The distribution block includes a housing which encloses the terminals and the ends of the conductors, and terminates the channel at the channel ends opposite of the end connectors. The distribution block can typically include ports in the housing which electrically connects the terminals, and thus the channel conductors, to electrical devices such as electrical receptacle outlets. 
     A typical housing can be an overmolded plastic one piece design. Such a housing requires that the conductors are installed in their respective channels or wire conduits and interconnected via the terminals, then the housing is molded over the terminals, conductor ends and wire conduit ends using an insert injection molding process. An insert injection molding process requires an insert injection molding machine, relatively expensive molds, and importantly, may have a machine cycle time of sixty seconds or more. Additionally, a cooling time may be required for the housing before normal handling of the housing and harness thereby increasing the effective machine cycle time. If the demand rate is less than the machine cycle time, (i.e., the customer demand requires harnesses be made in less than the machine cycle time), or if economic or competitive pressures require a shorter cycle time, overtime or multiple shifts are required, or additional machines and molds, or multiple cavity molds. All of the previously mentioned options have substantial price associated therewith. 
     The manufacturing of a distribution harness with an overmolded housing for the distribution block is additionally paced by the injection molding machine reliability and mold reliability. If the machine goes down, or the mold needs repair, the harness production stops unless spare machines or molds are available. Environmental conditions such as relative humidity or other contamination may further negatively impact production efficiencies of the molding process by increasing the amount of defective parts. 
     An overmolded distribution block housing is inherently inflexible relative to any post assembly modifications. For example, if a harness, including end connectors, channels and distribution block, has a capacity for eight conductors, but only four conductors are originally installed, the distribution block housing must be destroyed to add the additional connectors. 
     What is needed in the art is an electrical distribution block design and method, for distribution harnesses, which does not require the use of an insert injection molding process for manufacturing of the distribution block, and which provides for an easy and reliable mating and unmating of distribution block housing parts in a time efficient manner. 
     SUMMARY OF THE INVENTION 
     The present invention provides a modular electrical distribution block with snap fit housing parts. 
     The invention comprises, in one form thereof, a modular electrical component for use in modular office furniture, including a housing with a plurality of housing parts. The housing parts are being releasably engaged with each other. At least one of the housing parts includes a plurality of internal locating features, and at least one of the housing parts includes at least one electrical connector port. A plurality of terminals, are positionable in the housing parts relative to at least one of the plurality of locating features. Each terminal has a plurality of ends including one end associated with a respective electrical connector port. At least one releasable lock is provided, with each lock being associated with at least two of the plurality of housing parts and effecting releasable engagement between the housing parts. 
     An advantage of the present invention is the reduced manufacturing time required to assemble the distribution block and distribution harness. 
     Another advantage is the housing parts of the present invention are releasably engaged thereby allowing post assembly modification of the electrical distribution block and harness without the need to destroy the distribution block or harness assembly. 
     Yet another advantage of the present invention is the elimination of insert injection molding machines and associated molds in the manufacturing assembly of the distribution block and distribution harness. 
     A further advantage of the present invention is the presence of locating features in the housing parts for properly locating terminals thereby simplifying and error proofing the assembly process. 
     A yet further advantage of the present invention is the presence of mating edges in the distribution block housing parts allowing a repeatable and reliable interconnection of housing parts. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of an assembled distribution harness showing an embodiment of the snap fit distribution block of the present invention; 
         FIG. 2  is an exploded, perspective view of a distribution harness showing an embodiment of the snap fit distribution block of the present invention; 
         FIG. 3  is a sectional view of a snap fit embodiment of the male housing part of the present invention shown in  FIG. 2  as viewed from section line  3 — 3 ; 
         FIG. 4  is a sectional view of a snap fit embodiment of the female housing part of the present invention shown in  FIG. 2  as viewed from section line  4 — 4 ; 
         FIG. 5  is an exploded, perspective view of a distribution harness showing a staked fit distribution block embodiment of the present invention; 
         FIG. 6  is a sectional view of a staked fit embodiment of the male housing part of the present invention shown in  FIG. 5  as viewed from section line  6 — 6 ; and 
         FIG. 7  is a sectional view of a staked fit embodiment of the female housing part of the present invention shown in  FIG. 5  as viewed from section line  7 — 7 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one preferred embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and more particularly to  FIG. 1 , there is shown an electrical distribution harness  10  which generally includes end connectors  12 , wire conduits  14 , brackets  16 , receptacles  18 , conductors  20  ( FIG. 2 ) and electrical distribution block or modular electrical component  22 . Electrical distribution harness  10  is generally attached to a frame of a modular wall panel (not shown) using brackets  18  and is enclosed within the same modular wall panel. 
     End connectors  12  includes end connector housing  24  with end connector port  26  and enclosing end connector terminals  28 . End connector terminals  28  are electrically connected to conductors  20  within wire conduits  14 . End connector ports  26  can be connected to jumper cables (not shown), other distribution harnesses (not shown), electrical devices (not shown) or sources of electrical utilities (also not shown). 
     Wire conduits  14  mechanically connect at one end thereof to end connectors  12  and enclose conductors  20 . The other end of wire conduits  14  connect to respective sides of distribution block  22 . 
     Brackets  16  attach to wire conduit  14  and hold electrical distribution harness  10  to the frame of a modular wall panel (not shown) using feet  40 . Bracket clips  42  of brackets  16  mechanically hold receptacles  18  to electrical distribution harness  10 . Other embodiments of bracket  16  are possible. 
     Receptacle housing  50  of receptacle  18  mechanically connects to bracket  16 . Housing  50  includes receptacle ports  54  which electrically connect to electrical connector ports  60 , thereby connecting outlets  52  to a source of electrical power (not shown) through distribution harness  10 . Housing clips  56  releasably engage bracket clips  42  to mechanically hold receptacle  18  to bracket  16 . 
     Electrical distribution block or modular electrical component  22  ( FIG. 2 ) includes electrical connector ports  60 , housing  62  and terminals  68 . Terminals  68  electrically connect electrical connector ports  60  to conductors  20 . Electrical distribution block  22  is shown as an H-shaped distribution block including four ports  60  wherein a given H-shaped terminal  68  simultaneously connects all four ports  60  to a given conductor  20  by terminating each terminal end  70  in a different port  60 . Conductors  20  are terminated in electrical distribution block  22  at terminal connector  74  which is shown as a crimp connection but may be a soldered or welded connection. 
     Housing  62  includes at least a male housing part  64  and female housing part  66 . Male housing part  64  and female housing part  66  are repeatably positionable to configure housing  62  by the juxtaposition of housing part mating edges  76  such as male part projecting edges  78  in male housing part  64  and female part recessed edges  80  in female housing part  66  as shown in  FIGS. 2 ,  3  and  4 . Housing part inside portion  82  includes internal locating features such as tabs  84  in female housing part  66  which mate with terminal locating recesses  72  in each terminal  68  to maintain the proper orientation of terminals  68  in housing  62 , and to exclude incorrect orientations of terminals  68  in housing  62  during assembly. 
     Housing  62  further includes snap fitting releasable lock  86  with ramped projection  88  and recess or opening  90 . As housing parts  64  and  66  are brought together, and housing part mating edges  76  are juxtaposed, ramped projections  88  deflect slightly until housing parts  64  and  66  are in a closed position, respective of each other, at which point ramped projections  88  spring and lock into recesses  90 . The opening of housing  62  is achieved by simultaneously deflecting ramped projections  88  and pulling apart housing parts  64  and  66 . 
     In use, electrical distribution harness  10  is assembled by pulling conductors  20  through wire conduits  14  and housing parts  64  and  66 . Terminals  68  are positioned within housing parts  64  and  66  matching terminal locating recesses  72  in each terminal  68  with corresponding internal locating features  84 . Conductors  20  are individually connected, at an end, to a respective terminal  68 . Wire conduits  14  are connected to a respective housing part  64  or  66 , and housing parts  64  and  66  are joined together. When housing parts  64  and  66  are completely joined they lock via snap fitting releasable lock  86 . Conductors  20  are connected at their other end to end connector terminals  28 . End connectors  12  are connected to their respective wire conduits  14 . Brackets  16  and receptacles  18  are mounted and connected to electrical distribution harness  10  as required. Electrical distribution harness  10  is mounted in a modular wall panel (not shown) and end connector ports  26  are connected to jumper cables (not shown), other distribution harnesses (not shown), electrical devices (not shown) or sources of electrical utilities (also not shown). Electrical connector ports  60  in electrical distribution block  22  can be connected to other receptacles  18  or electrical devices (not shown). 
     In another embodiment ( FIGS. 5–7 ), electrical distribution harness  100  includes staked fit electrical distribution block or modular electrical component  101  including housing  102 . Housing  102  includes staked fitting releasable lock  107  having cylindrical projections  108  on female housing part  106  and circular recesses  110  on male housing part  104 . Other components are as described in the previous embodiment. In use, the locking of the embodiment of  FIGS. 5–7  includes joining male housing part  104  and female housing part  106 , in part, through the insertion of cylindrical projections  108  into respective circular recesses  110 . After the complete joining of male housing part  104  and female housing part  106 , the locking of the respective housing parts includes staking an end of cylindrical projections in place using a heat gun, and/or compression, or other methods. Other components of electrical distribution harness  100  are the same as the previous embodiment. 
     While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.