PROGRAMMABLE JUNCTION BOX

Abstract: An automobile junction box (2), programmable in relation to vehicle options that may be required, houses printed circuit boards (24, 25) having receptacles (28) for receiving tabs (36) depending from an elongated member (34). The tabs connect the circuit pathways (26) corresponding to vehicle options. The selected circuit pathways may be modified by the inclusion of a second set of receptacles (29) on the printed circuit boards for receiving electrical components (l4) such as diodes, resistors, zener diodes and the like.

Description: This invention relates generally to automobile wiring and particularly to automobile junction boxes. Before the introduction of junction box technology, wire harnesses for each automobile had to be individually tailored for particular vehicle options. Wire harnesses were overly complex, required unreliable and costly splicing, and necessitated high labor costs. Achieving standardization of vehicle wiring and the concomitant savings associated therewith, such as high reliability and low labor and supply costs, was impossible. With the introduction of printed circuit junction boxes, wire harness complexity and cost were reduced since the junction boxes provided a plurality of previously individually wired pathways for the centralized distribution of electrical signals. Wire harness standardization was possible to a limited extent, yet individual wire harnessing was still required for various vehicle options, particularly those requiring additional electrical components for proper operation. The electrical components (such as a diode) were generally hard wired into an appropriate harness causing the harnesses to be bulky, difficult to service and install, and of little use for other vehicle options. Because of the individual wiring required, complete standardization of automobile wiring has not been achieved; various wire harnesses are required, and junction boxes require differing internal circuitry or complicated external connections to accommodate each vehicle option. The prior art addresses the problem of standardization by attempting to make junction boxes more flexible to accommodate standardized harnesses and available options. US-A-4,208,080 discloses a junction box housing printed circuit boards connected by a plurality of individual stakes that are used to accommodate different vehicle functions by connecting the appropriate circuit paths imprinted in the circuit boards. The box is complicated, has a high margin for error (particularly relating to misinsertion of the stakes), and insertion of the stakes requires a great deal of labor. US-A-4,552,423 discloses a single programmable shunt (11 having prongs (13) to provide multiple connections between a socket (25) and selected terminals to connect a selected circuit. However, the shunt is made of a conducting material which limits its ability to connect more than one discrete circuit. Similarly, US-A-4,464,003 discloses a programmable bus bar (20) made of a conductive material to interconnect selected of conductors (18). The bus bar can only interconnect one discrete circuit. US-A-4,487,464 discloses a plurality of different bus bars (23, 30, 33, 40, 43) making the required electrical connections for a plurality of discrete circuits. A different bus is required to connect each discrete circuit, engendering high labor costs and high probability for error particularly relating to the insertion (or misinsertion) of each bus. An automobile junction box according to the precharacterizing portion of independent claim 1 is disclosed in DE-A-30 48 451 which is exemplary of prior art junction boxes wherein spaced upper and lower circuit boards, electrically interconnected by corner posts, are enclosed in a two-piece housing constructed of electrically insulative material. Each circuit board is imprinted with a plurality of circuit pathways which electrically interconnect specific wire harness terminals formed in the lower half of the housing through specific relays and fuses disposed in the circuit pathways through terminal connections provided in the upper half of the housing. The disclosed junction box is not selectively programmable, but rather has particular circuit pathways which cannot be modified. It is therefore the object of the invention to provide an automobile junction box that permits to simplify the interconnection of wires and other electrical components in vehicles when different vehicle options are required. To achieve this there is provided, according to the invention, an automobile junction box comprising a housing having a plurality of first openings for receiving wire harness connectors and a plurality of second openings and enclosing circuit board means having a plurality of separate circuit pathways printed thereon for providing electrical interconnections between at least two of a plurality of wire harness connection terminals associated with the plurality of first openings, characterized in that each of the separate circuit pathways has a first open terminal receptacle associated therewith and disposed in one of said second openings and by associated connector means having an electrically insulating base member and a plurality of electrically conductive tabs equal to or less in number than the number of second openings in the housing directly connected to and depending from one side of said base member, said electrically conductive tabs being selectively numbered and arrayed on said base member for insertion into a plurality of said first receptacles so as to interconnect two or more of the plurality of separate circuit pathways so as to complete at least one circuit between at least two of the wire harness connection terminals. Accordingly, the circuitry of the junction box can be standardized. Various vehicle options are accommodated by using a connector means corresponding to the desired vehicle options. This minimizes wire harness complexity. Advantageous embodiments of the automobile junction box are defined in the dependent claims 2 to 7. The automobile junction box will now be described in greater detail with reference to the drawings, wherein: Fig. 1 is an exploded perspective view of the junction box of this invention; and Figs. 2-5 are perspective views, partly broken away, of a bus bar according to different aspects of this invention. Referring generally to Fig. 1, a junction box 2 for providing electrical connections for automobile wiring has a two part housing 4, 6, each part having holes for the interconnection of various electrical elements to the box. Top part 4 includes a plurality of identical rectangular openings 8 for receiving standardized wire harness connectors 10 that provide connections for standardized wire harnesses 11 terminating in each connector 10. Top part 4 has a row of juxtaposed inlets 12 parallel to wire harness openings 8 for receiving electrical components 14. Closely contiguous to the electrical component inlets 12 are programming slots 16 for receiving a bus bar 32 the slots being arranged parallel to each other in an elongated row. Abutment stops 18 protrude from a surface 19 of the top part 4, at each end of the row. One stop 18 has a polarizing rib extending toward the other stop. Bottom part 6 of the junction box has apertures 20 for the interconnection between relays 22 and/or electrical/electronic module 23 and the junction box. The junction box parts are joined by any known means such as screws or snaps (not shown). Housed within the junction box, are two, stacked printed circuit boards 24, 25 joined electrically by any known means. The printed circuit boards have conductive pathways imprinted thereon (shown generally at 26), electrically joining the appropriate elements for the distribution of electrical signals to or from vehicle options. Each circuit board has a plurality of terminals aligned with the appropriate hole in each part of the junction box to electrically connect the inserted elements to the circuit pathways. Board 24 has a set of female terminals 28 aligning with slots 16, a second set of female terminals 29 aligning with inlets 12 and a set of male plugs 30 aligning with openings 8. Board 25 has a set of female receptacles (not shown) aligning with apertures 20. A bus bar 32 is provided to electrically join selected circuit pathways 26 corresponding to a vehicle's options, thereby programming the junction box for the distribution of electrical signals to these options. The bar has an elongated, rectangular member 34 constructed of an electrically insulating material, such as a plastic. The length of the member corresponds to the length of the row of programming slots 16, and fits firmly between the abutment stops 18 to ensure proper alignment of the member 34 in relation to the slots 16. One end of member 34 has a polarizing notch 35 for mating with rib 21, thereby ensuring that the member is not inserted between the stops 18 in a reverse manner. The member has a series of electrically conductive tabs 36 depending from one side thereof. The tabs 36 are arranged at selected locations on the member to fit within the programming slots and to connect selected circuit pathways by means of the female receptacles 28. Each tab may connect circuit pathways by connecting separated female terminal electrodes (shown generally as a receptacle at 28), each electrode corresponding to a separate circuit pathway, or may join two or more circuit pathways by establishing electrical connection between each tab and the circuit pathways corresponding to each receptacle 28. The tabs may be connected by circuits 38 printed on the face of the member (see Figs. 3 and 4), or the depending tabs may be integrally connected by members 37 to provide the proper connection (see fig. 5). In a further embodiment, the tabs may be electrically connected by electrical components such as diodes 40, zener diodes 42 or resistors 44 to modify the connected circuits to properly operate the selected options (see fig. 2). The tabs may be connected to the member by pins 46 projecting from the member fitting through holes in the tabs (see Fig. 5) or by spot welding. Electrical components 14 may also be inserted in the junction box through the electrical component inlets 12 into the appropriate printed circuit female receptacles 29. The electrical components 14, such as zener diodes, diodes and resistors, which may be polarized for proper orientation with a circuit, ensure that the option chosen has the correct circuitry characteristics for proper operation. Fuses 48, shaped similarly to the electrical components 14, may be inserted in the electrical component inlets 12 to ensure that a vehicle's options are properly protected. Other electrical components (not shown) such as filters, capacitors and the like may also be inserted therein to properly operate the selected circuits. In operation, each automobile receives an indentical junction box having circuit boards therein for accommodating a range of available options. A bus bar 32 corresponding to particular vehicle options is inserted into the slots 16 provided in the junction box and into the corresponding female receptacles 28 joining the conductive pathways corresponding to the vehicle's options. The circuits that require particular characteristics are modified by electrical components 14 (or fuses 48) inserted through the inlets 12 into receptacles 29. The appropriate relays and electrical/electronic modules are inserted into the box through apertures 20. The wire harness connectors 10 are inserted through openings 8 to engage plugs 30. Assembly is then complete. Harnesses and connectors can be standardized because each harness can service a variety of options due to the circuit flexibility of the junction box and the inclusion of the circuit modifying elements in the box. For instance, a manually regulated air conditioning system might require one connecting circuit while an automatically regulated air conditioning system, which requires sensor input, would require another connecting circuit. The bus bar would connect the proper circuit to the appropriate wire harness through the appropriate pathways, but in either case, the same wires in that harness carry the appropriate electrical signals to the air conditioner. This is particularly true if one system or the other requires additional electrical components. The required component is included in the box or on the member 34 so that an identical harness, now less complex, may still service either option in other vehicles. Accordingly, what is provided is a standardized, simplified, wiring system for an automobile, having a standardized junction box with sufficient flexibility, provided by a single, easy to install bus bar, to accommodate the various options that may be required in a vehicle through standardized, less complex wire harnesses.

Claims: Automobile junction box (2) comprising a housing (4, 6) having a plurality of first openings (8) for receiving wire harness connectors (10) and a plurality of second openings (16) and enclosing circuit board means (24,25) having a plurality of separate circuit pathways (26) printed thereon for providing electrical interconnections between at least two of a plurality of wire harness connection terminals (30) associated with the plurality of first openings (8), characterized in that each of the separate circuit pathways (26) has a first open terminal (28) associated therewith and disposed in one of said second openings (16), and by associated connector means (32) having an electrically insulating base member (34) and a plurality of electrically conductive tabs (36) equal to or less in number than the number of second openings (16) in the housing (4,6), directly connected to and depending from one side of said base member (34), said electrically conductive tabs (36) being selectively numbered and arrayed on said base member (34) for insertion into a plurality of said first receptacles (28) so as to interconnect two or more of the plurality of separate circuit pathways (26) so as to complete at least one circuit between at least two of the wire harness connection terminals (30). Junction box as recited in claim 1 further characterized by at least one set of second open receptacles (29) electrically connected to at least two of the plurality of separate circuit pathways (26) forming terminals thereon for receiving electrical components (14) to modify electrical characteristics of said circuit pathways. Junction box as recited in claim 2 further characterized in that said components (14) are resistors, diodes or zener diodes. Junction box as recited in claim 1 further characterized in that the second openings (16) in which the first open terminal receptacles (28) are disposed are arranged parallel to each other in an elongated row and in that said connector means (32) comprises an elongated member (34) constructed of an electrically insulating material and a plurality of electrically conductive tabs (36) depending from one side thereof and likewise arrayed parallel to each other in an elongated row. Junction box as recited in claim 4 further characterized by electrically conductive paths (38) on said elongated member (34) interconnecting at least two of the plurality of electrically conductive tabs (36) depending from the one side thereof. Junction box as recited in claim 4 further characterized in that at least two of the plurality of electrically conductive tabs (36) are electrically interconnected by an integral connecting member (37). Junction box as recited in claim 4 further characterized in that at least two of the plurality of electrically conductive tabs (36) are electrically interconnected by electrical components (40,42,44).

Inventors: HENDERSON, BRIAN EARL, MAUE, H:WINSTON, SZUDAREK, ROBERT GERALD
Applicants: UNITED TECHNOLOGIES AUTOMOTIVE, INC.
Application year: 1987
Main classification: H01R29
IPC codes: H01R9, H01R31, H01R29, H01R13, B60R16, H05K1, H05K7, H02G3