Flex circuit electrical connector

[0002] This invention relates to an electrical connector, and more specifically to a flex circuit electrical connector.

[0003] Electrical connectors often have multiple terminals encased within an electrical connector housing or shroud. These terminals are individually crimped to multiple insulated conductors to complete the electrical circuit. Flex circuits or flat electrical conductors arranged along a single sheet of insulating substrate are also known within the art. Terminals are also known to be crimped at the end of the substrate individually engaging each individual conductor. After crimping, these terminals are then placed and locked within the core or housing of an electrical connector. The automation process of assembling an electrical connector which utilizes a flex circuit is limited. Furthermore, forming multiple rows of terminals from a single flex circuit within an electrical connector to establish a desired array or shape is also limited.

[0004] This invention provides a multi conductor electrical connector having two stacked carriers each having an inner face defining a series of grooves which individual house a plurality of terminals configured in rows. The conductor ends of a multi-conductor cable or flex circuit are preferably sonic welded to the rearward ends of the pre-mounted terminals within the carriers. The stacked carriers are inserted through a side clearance of a rearward clip portion of a shroud from a lateral direction and snap fitted therein. Once in the shroud, the opposite ends of the terminals are exposed through a forward opening defined by a forward annular portion of the shroud. Preferably, the electrical connector has a retaining clip which snap fits to, and between, the carriers and engages the terminals, preventing rearward movement of the terminals within the carriers when the terminals engage a mating connector. Longitudinally, extending within each groove is a flex arm which locks the terminals in place.

[0005] A feature of the present invention is the ability to engage or sonic weld the conductors of a flex circuit after the terminals are arranged within the carriers, thereby enhancing the manufacturing process. Another feature of the present invention is proving an electrical connector having two rows of terminals engaged to a single flex circuit.

[0006] The presently preferred embodiments of the invention are disclosed in the following description and accompanying drawings wherein:

[0007] FIG. 1 is a perspective view of an electrical connector of the present invention;

[0008] FIG. 2 is a perspective view of a first and second carrier engaged to a flex circuit;

[0009] FIG. 3 is a perspective view of the first and second carriers engaged to the flex circuit when folded over upon one another;

[0010] FIG. 4 is an exploded perspective view of the electrical connector;

[0011] FIG. 5 is a partial perspective cross sectional view of the electrical connector taken along line 5—5 of FIG. 3 viewing in the direction of the arrows;

[0012] FIG. 6 a cross section view of the electrical connector taken along line 6—6 of FIG. 3 viewing in the direction of the arrows;

[0013] FIG. 7 is a perspective view of a retaining clip of the electrical connector; and

[0014] FIG. 8 is a perspective view of a second embodiment of the electrical connector.

[0015] Referring to FIGS. 1-3, an electrical connector 20 is shown having a flat multi-conductor substrate or flex circuit 22 with two banks 23 of conductors 24. A series of terminals 28 are positioned within a first insulating carrier 26, then sonic welded to the ends of each respective individual conductor 24 of the first bank 23 of the flex circuit 22. Likewise, a second carrier 30 houses a series of terminals 28 engaged to the ends of the conductors 24 of the second bank 23 of the same flex circuit 22. The flex circuit 22 folds over forming a longitudinally extending return bend 25 stacking the first bank 23 with the second bank 23. Consequently, the terminals 28 are configured in two stacked rows and, likewise, the first carrier 26 is stacked to the second carrier 30. The flex circuit 22 is made substantially of an electrical insulating substrate material and the return bend 25 is generally free of metallic conductor strips.

[0016] With the first carrier 26 engaged to the second carrier 30 in a stacked formation, the carriers are simultaneously inserted laterally into a shroud 32. The shroud 32 has a forward annular portion 34 defining a forward opening 48 through which the terminals 28 are exposed for the purpose of electrical engagement to a mating connector, not shown. Shroud 32 has a rearward clip portion 36 defining a side clearance 38 through which the stacked first and second carriers 26, 30 pass laterally, during assembly as best shown in FIGS. 4 and 5. A retaining clip 40 inserts into the rearward clip portion 36 between the first and second carriers 26, 30 from behind to assure the terminals 28 are properly positioned within the carriers 26, 30. The shroud and the carriers are made of an electrical insulating material such as, and preferably, plastic.

[0017] Referring to FIGS. 2-4, the first and second carriers 26, 30 are identical to minimize manufacturing costs. Each carrier has an inner face 42 which defines a series of elongated grooves 44 wherein the terminals 28 reside. The grooves 44 extend through a forward face 46. Face 46 is exposed through the forward opening 48 of the shroud 32 when the electrical connector 20 is assembled. Extending longitudinally forward within each groove 44 is a cantilevered locking arm 49 which flexes to accept the terminal 28 within the groove 44, and returns to lock the terminal 28 in place. In assembly, the terminal 28 is engaged to an inner surface of the flex arm 49. An opposite outer surface of the arms 49 are flush with the inner face 42 of each carrier 26, 30. The outer surface of the arms 49 of the first carrier 26 engages the outer surface of the arms 49 of the second carrier 30 when the carriers are stacked thereby preventing any further flexing of the arms and locking the terminals 28 in place. Projecting rigidly from the inner face 42 of each carrier 26, 30 is a post 50 which is disposed substantially near a side edge of the carrier. A post hole 52 is located along the opposite edge of each carrier 26, 30. The posts 50 and the holes 52 are fully mated when the inner face 42 of the first carrier 26 is in contact with the inner face 42 of the second carrier 30, thereby aligning and preventing the carriers from sliding in relation to one-another.

[0018] Both carriers 26, 30 have an opposite or outer face 54. A series of sonic welding access ports 55 extend through the outer face 54 of the carrier and communicate with each respective groove 44 defined by the inner face 42. During assembly, the flex circuit 22 and the terminals 28 are orientated between a first and second member of a sonic welding assembly tool. The first member inserts through each port 55, and the second member of the tool contacts the flex circuit 22 from the opposite side, enabling the tool to weld the conductors of the flex circuit 22 to the terminals 28. After welding, the carrier 26 is stacked, or folded over, upon the carrier 30. A variety of other means, such as laser welding or gluing, may also be used to engage the terminals 28 to the conductors of the circuit 22

[0019] After the sonic welding is complete, the stacked carriers 26, 30 are inserted laterally and snap locked into the shroud 32. To align and lock-fit the carriers 26, 30 properly within the shroud 32, the outer face 54 of each carrier defines a laterally extending slot 56 which receives a respective ledge 57 projecting radially inward from a back most perimeter of the rearward clip portion 36 of the shroud 32. The two ledges 57 are parallel and project in opposition to one-another. Each ledge has a ramped prong 60 projecting radially inward from the respective ledge 57, both disposed at the exposed end of each ledge 57 near the side clearance 38. During assembly, as the stacked carriers 26, 30 are laterally inserted through the side clearance 38, the slots 56 receive the respective prongs 60 which are temporarily pried outward and away from each other achieved by the ramp feature on each prong as it makes contact with the respective carrier 26, 30. When the carriers 26, 30 are fully inserted into the shroud 32 the prongs 60 snap fit past the trailing edges or sides of the respective carriers 26, 30 locking the carriers within the shroud 32.

[0020] Referring to FIGS. 5 and 7, the retaining clip 40 and snaps locks into the carriers 26, 30. Clip 40 has a leading upper return bend 62 and an opposite leading lower return bend 64, each bend having a row of forward projecting tangs 66 which engage a rearward facing portion of the terminals 28 within each respective groove 44 of the carriers 26, 30. In the present embodiment, each carrier 26, 30 is associated with five terminals 28, therefore, the upper and lower return bends 62, 64 each have five tangs 66. The upper return bend 62 has a rearward extending wing 67 which is planar and parallel to an identical rearward extending wing 67 of the lower return bend 64.

[0021] Referring to FIGS. 6 and 7, each carrier 26, 30 has at least one ramped projection 68 extending radially inward from the inner face 22 just forward of and between the ports 55. When the retaining clip 40 inserts into the assembled connector 20 from the rear, the projections 68 cause the wings 67 to flex inward until the projections snap into respective apertures 70 which extend through each wing. To assist this snap fit, each wing 67 has a ramped surface 72 associated with each aperture 70 and which slopes radially outward in the rearward direction and up to the respective aperture 70. When assembled, the wings 67 are engaged between the carriers 26, 30 and a planar tab portion 74 of the clip 40 projects outward therefrom, between the wings 67 acting as a strain relief and routing feature for the flex circuit 22. Furthermore, the tab portion 74 provides a means to grip the retaining clip 40 during insertion into or disassembly of the electrical connector 20.

[0022] Referring to FIG. 8, a second embodiment of the electrical connector 20′ is shown wherein the flex circuit 22 of the first embodiment is replaced with a plurality of individually electrically insulated conductors 22′. Electrical connector 20′ is otherwise identical to connector 20.

[0023] Although the preferred embodiments of the present invention are disclosed various changes and modifications may be made thereto by one skilled in the art without departing from the scope and spirit of the invention as set forth in the appended claims. Furthermore it is understood that the terms used herein are merely descriptive rather than limiting and various changes may be made without departing from the scope and spirit of the invention.