Electrical Connector

This invention relates generally to electrical connectors and, more particularly, to connectors for electrically connecting a flat multi-conductor cable to a printed circuit board.

Prior electrical connectors for securing flat multi-conductor cable to a printed circuit board have been composed of a number of components resulting in a complex and costly connector. Other connectors have been constructed on the plug-and-socket arrangement where special fittings are required to accomplish the electrical connection. Still other types of connectors employ members which cut into or pierce the conductor in the cable. All of these prior connectors are also subject to having the cables pulled loose from the connectors, thereby requiring complex structures to provide the strain relief required and thus further adding to the cost of the connector. In addition, the preparation required of the cable and the printed circuit board in order to use these prior connectors have been quite extensive, thus further detracting from their use.

It is therefore the principal object of this invention to provide a connector for connecting a flat multi-conductor cable to a printed circuit board which is simple in its construction and use and therefore low in cost. It is a further object of this invention to provide a connector which is easily mounted on a printed circuit board while providing positive contact and proper orientation of each conductor in the cable with the conductors on the printed circuit board. It is another object of this invention to provide an electrical connector having means to provide uniform strain relief over the entire width of the cable thereby insuring against the dislodging of the cable from the connector. In order to attain these and other objects of the invention, there is provided a flat elongated support member having a plurality of front mounted tab members each having a foot portion and a plurality of latching members each of which includes a recessed area for latching the edge of the printed circuit board. The support member further includes a slot extending through the member and a rib portion located on the bottom surface of the support member. Prior to the mounting of the connector to the circuit board, the lower surface of one end of the cable is removed exposing one side of the conductors located therein. The prepared end of the cable is then inserted through the slot in the support member and along the lower surface of the support member. The tab members of the support member are then inserted within locating apertures in the printed circuit board with the foot portions engaging the lower surface of the printed circuit board. The support member is then rotated to a latching position on the printed circuit board where the edge of the circuit board is positioned within the recessed area of the latching members, the rib portion forcing the exposed conductors in the cable against the exposed conductors on the printed circuit board.

FIG. 1 is a perspective exploded view of the connector, the flat multi-conductor cable before insertion within the connector and the printed circuit board with the locating apertures for the connector.

FIG. 2 is a plan view of the end of the cable showing a portion of the insulation material removed to expose one side of the conductors imbedded in the cable.

FIG. 3 is a perspective view of the connector formed in accordance with the present invention.

FIG. 4 is a cross-sectional view of the connector being inserted into the printed circuit board.

FIG. 5 is a view similar to FIG. 4 showing the connector in a latched position on the printed circuit board.

FIG. 6 is a perspective view of the connector formed in accordance with the present invention showing details of the underside of the connector.

FIG. 7 is an end view of the connector shown mounted on the circuit board.

Referring now to the drawing, and more particularly to FIG. 1, there is shown a conventional flat multi-conductor cable 20 comprising upper 22 (FIGS. 4 and 5) and lower 24 layers of insulation, as for example, a polyester material such as "Mylar" manufactured by and a trademark of E. I. Du Pont de Nemours and Co., between which is sandwiched a plurality of thin parallel copper conductors 26. In order to prepare the cable for use with the connector of the present invention, it is necessary to remove a strip of insulation from one side of the cable 20 thereby exposing the conductors 26. This removal of the insulation leaves an edge 28 of the insulation on the lower surface of the cable as shown in FIGS. 1 and 2.

The connector 30 (FIGS. 1 and 3) of the present invention comprises a one-piece elongated member which may be fabricated by molding or the like and is preferably constructed of any type of electrically insulating material such as Delrin, an acetal resins material manufactured by and a trademark of E. I. Du Pont de Nemours and Co. The present embodiment of the connector 30 is shown having molded at the lower front edge thereof three depending tab members 32 (FIGS. 3 and 6) each including a horizontal extending foot portion 34. At the lower rear edge of the connector 30, there are molded three depending latch fingers 36 (FIG. 6) each having a lower cam surface 38 extending at an angle of approximately 55.degree. with a horizontal plane, the upper end of which forms one wall of a slot 40 located in the front edge of the finger 36 (see also FIG. 4). The slot 40 has a width which is equal to the thickness of the printed circuit board 42, the function of which will be described hereinafter.

Extending lengthwise in the connector 30 is a slot 44 (FIGS. 1 and 3) which is substantially equal in length to the width of the cable 20 and wide enough to accomodate the thickness of the cable 20, the slot 44 extending through the connector 30 to communicate with a lower surface 46 of the connector. As shown in FIGS. 4 and 5, the lower surface 46 is recessed from a rear lower surface 48 to accomodate the cable 20 when the connector is latched to the printed circuit board 42. Formed as part of the lower surface 46 of the connector is a rib portion 50 extending outwardly from the surface 46 and lengthwise of the connector 30. The rib portion 50 is dimensioned to press the cable 20 into engagement with the printed circuit board when the connector is mounted on the printed circuit board as will be described more fully hereinafter. As shown in FIG. 1, located on the upper surface 52 of the printed circuit board 42 are a plurality of copper conductors 54 to which the conductors 26 in the cable 20 are to be connected. Also located in the circuit board 42 are mounting apertures 56 which help mount the connector 30 to the circuit board 42 and orientate the conductors 26 in the cable 20 with respect to the conductors 54 on the circuit board.

In operation, the flat cable 20 is first assembled within the connector 30, with the end of the cable 20 which has had a portion of the insulation removed (FIG. 2) being threaded through the slot 44 and bent in a direction to extend along the lower surface 46 of the connector and adjacent the rib portion 50 (FIG. 4). The connector 30 is then mounted to the printed circuit board 42 by inserting the tab members 32 thereof through the apertures 56 in the circuit board thereby positioning the foot portions 34 of such tab members adjacent the lower surface 58 (FIGS. 4 and 5) of the circuit board 42. The connector 30 is then rotated toward the board 42 to engage the cam surfaces 38 of the latch fingers 36 with the upper corner of the edge of the circuit board. Further pressure on the connector 30 will deflect the latch fingers 36 outwardly until the edge of the circuit board snaps into the slots 40 thereby latching the connector 30 to the printed circuit board 42. This latching movement of the connector 30 will force the rib portion 50 thereof into engagement with the cable 20 and against the upper surface 52 of the printed circuit board 42 resulting in the exposed conductors 26 in the cable 20 engaging and maintained against the aligned conductors 54 on the printed circuit board thereby completing an electrical connection between the conductors.

The advantages flowing from the use of the novel connector forming the present invention will be readily apparent to those skilled in the art. The latching of the connector 30 to the printed circuit board 42 by anchoring the connector in the board apertures 56 and by engaging the edge of the printed circuit board with the fingers 36 provides a secure mounting of the connector 30 which eliminates any chance of movement of the connector on the circuit board. The mounting of the cable 20 within the slot 44 in the connector 30 together with the pressure of the rib portion 50 on the cable 20 provides the necessary strain relief which prevents any inadvertent or undesirable movement or removal of the cable with respect to the connector and the printed circuit board. It is obvious that the connector may be easily and quickly removed from the circuit board by merely bending the lower end of each of the latching fingers 36 sufficiently to release the edge of the circuit board from each of the slots 40 in the connector.

The connector 30 can be constructed to accomodate any width of cable 20 that is desired. By providing the apertures 56 in the circuit board through use of a template, extremely close tolerances can be obtained for aligning the connector on the circuit board. It is obvious from the drawing that the connector 30 is simple in its design which reduces its cost of construction to a minimum. Its low profile when mounted on the circuit board (FIG. 7) allows the connector to be used in stacks of circuit boards where space is at a premium.

While the principles of the invention have now been made clear in the illustrated embodiment, it will be obvious to those skilled in the art that many modifications of structure, arrangements, elements and components can be made which are particularly adapted for specific environments and operating requirements without departing from these principals. As an example, the latching fingers 36 may be molded as one continuous edge extension of the connector while still functioning in the manner intended. The appended claims are therefore intended to cover any such modification, within the limits only of the true spirit and scope of the invention.