Abstract:
An integral terminator/connector assembly permits a terminator to be connected to a flat cable in a single step after pre-assembly of the terminator to the connector. The terminator is pre-connected to the connector by locating a terminator circuit board on a DIP-type connector substrate between the two rows of pins, and bending the pins over the edge of the terminator board. The connector may include a molded plastic cover to enclose the terminator board.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention. 
     The present invention relates to electrical connectors and, in particular, to an assembly and method for connecting a terminator to a cable. 
     2. Description of Related Art. 
     Conventionally, cable termination circuits, including terminators, noise suppression circuits, and peak suppressors, have had to be electrically connected to a cable by first connecting a connector to the cable, and then connecting the circuit to the connector, for example by plugging the connector into outlets provided on the circuit board. 
     While this method of attaching a cable termination circuit to a cable is not complicated, it has been proposed to make the attachment process even simpler by pre-integrating the connector and the circuit so that a user of the termination circuit can easily connect the circuit board to the cable by simply attaching the connector to the cable, without the need for subsequently adding a circuit board. 
     An example of a prior art assembly for connecting a circuit to a flat cable, in which the circuit may be pre-connected to the connector, is found in Pat. No. 4,610,493 to Masek. Masek discloses a ribbon cable connector which carries two rows of terminal pins. A transient suppression circuit consisting of resistors is pre-connected to the terminals of the connector. After attaching the connector to the cable, clips and a cover are added for the purpose of holding the assembly together. 
     While relatively simple, the assembly of Masek is disadvantageous because it requires that each of the circuit elements be soldered directly to the pins of the connector. Furthermore, the cover cannot be provided as an integral part of the assembly, which means that the circuit must lie exposed until after it has been mated with the cable. If the circuit terminator is to be attached to a cable in situ, e.g., by an unskilled personal computer owner, there is a great danger that the circuit will be damaged during connection to cable. 
     SUMMARY OF THE INVENTION 
     The invention improves upon the prior art by providing an optimally simple and reliable assembly and a method for attaching a cable termination circuit to a flat cable. Essentially, the assembly includes a substrate provided with rows of pins extending from one side of the substrate and insulation displacement contacts extending from the other side of the substrate, the pins and contacts being electrically connected to each other. The substrate and a base are adapted to sandwich the flat cable, at which time the insulation displacement contacts penetrate the insulation of the cable and connect the pins to the conductors in the cable. 
     Preattached to the substrate is a printed circuit board which carries the cable termination circuit. The circuit board fits between the rows of pins and the pins are bent over the circuit board to make contact with the printed circuit. The substrate and base may be parts of an off-the-shelf Dual In-Line Package (DIP) connector, providing a very simple, reliable, and inexpensive method of connection to the flat cable. 
     In a preferred method, the circuit board is pre-connected to the substrate, or to the top half of a DIP connector, by placing it between the rows of pins. The pins are then bent over the circuit board and the ends of the pins are soldered to conductive landings printed onto the circuit board for the purpose of electrically connecting the circuit to the pins. The substrate can then be attached to a cable at any time by simply placing the cable between the substrate and the base, and attaching the base to the substrate. 
     Also included in the preferred embodiment is a cover which can be placed on the substrate to enclose the circuit board, the cover protecting the circuit both before and after connection to a cable. The substrate, the circuit board, and the cover form an enclosed unit which can be provided to the user separately from the base, the user connecting the base and substrate to the cable of his choice. The entire assembly can be disassembled from the cable and put on a different cable without exposing the circuit. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the substrate, circuit board, and optional cover of the terminator assembly according to a perferred embodiment of the invention. 
     FIG. 2 is a perspective view of the preferred terminator assembly, with the cover mated to the substrate and including a separate base. 
     FIG. 3 is a side view showing the substrate, circuit board, base, and cover of the preferred embodiment, and including a ribbon cable. 
     FIG. 4 is a perspective view of the preferred assembly after it has been attached to the cable. 
     FIG. 5 is a top view of the substrate and circuit board of the preferred embodiment, including an exemplary terminator circuit. 
     FIGS. 6(a)-(d) illustrate the preferred method of connecting a termination circuit to a ribbon cable. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     1. Terminator/Connector Assembly. 
     FIGS. 1 through 4 show all of the components of a preferred embodiment of the invention, except for the cable termination circuit itself, which is shown in FIG. 5. The cable termination circuit is illustrated as a terminator, but other similar cable-ending circuits may be substituted including, but not limited to, filtering and noise suppression circuits. 
     A substrate 2 includes two rows of pins 3 and insulation displacement contacts 5. As shown in FIG. 3, contacts 5 are actually extensions of pins 3 so that electrical current can flow from pins 3 to contacts 5. Such insulation displacement contacts and corresponding pins are known in the art and their structure forms no part of this invention. It will be appreciated by those skilled in the art that numerous variations of the pins and contacts are possible, including the use of multiple-row pin arrangements. 
     Circuit board 10 is located between the rows of pins 3 on the substrate 2 and fixed with respect to the substrate by soldering of the pins to conductive landings 18 provided on the circuit board. As shown in FIG. 5, conductive landings 18 are provided in positions corresponding to pins 3. The landings are part of a printed terminator circuit which includes standard terminator components such as resistors 15 and 16, and capacitor 17. 
     The leads of the various components may be attached to the printed board in conventional fashion, either leaded or surface mounted, or the components themselves may be printed onto the board. Each of the pins is bent and soldered to a corresponding landing, thereby electrically connecting the circuit on the board with the pins 3 and contacts 5. 
     As shown in FIG. 2, recesses 4 may also be provided in the base to accommodate contacts 5, and recesses 9 provided to accommodate thicker areas of the cable. The specific shape and arrangement of recesses 4 and 9 will depend on the shape of the cable, and the design of the recesses being well within the skill of the ordinary artisan. 
     Referring to FIG. 3, the substrate 2 is provided with recesses 6 for aligning the substrate with base 7, and for clamping the base onto the substrate. Base 7 advantageously includes extensions 8 adapted to mate with recesses 6 such that extensions 8 and recesses 6 can be snapped together when the cable is placed between them, thereby securing the base and substrate together with the cable sandwiched therebetween. Other arrangements for attaching substrate and base are, of course, also possible, and are intended to be within the scope of the invention. 
     Cover 13 fits over the entire substrate. As shown in FIG. 3, shelf 14 is provided internally of the cover for aligning the cover with the substrate. However, other means for attaching the cover to the substrate may be used, numerous variations of which will occur to those skilled in the art. The cover itself may be made of molded plastic and include a label in addition to protecting the terminator circuit. It may be glued to the substrate along shelf 14, or attached by any other convenient means. 
     FIG. 4 shows the cover 13 secured to the substrate (not shown) which is in turn clamped to base 7 with a cable 11 sandwiched therebetween such that conductors 12 of the cable are electrically connected to the circuit board on the substrate (also not shown). 
     It will be recognized by those skilled in the art that the base and substrate as described above, when two rows of pins are used, are essentially equivalent to a DIP connector. Furthermore, by combining a DIP with a termination circuit in the manner described above, bending the two rows of pins over the edge of a board placed between the pins, the cost of the assembly can be minimized. 
     It is contemplated that the priciples of the invention will be applicable to a wide variety of DIP connectors, and therefore will also be useful in a wide variety of flat or ribbon cable applications. By using an already available DIP connectors, only the cover and circuit board will have to be specially manufactured. 
     2. Method. 
     An especially advantageous method of connecting the termination circuit to the cable 11 will now be described in connection with FIGS. 6a to 6d. As shown in FIG. 6a, circuit board 10 is placed between the rows of pins and the pins are bent over the circuit board to contact the circuit at landings 18, at which time the pins may be soldered to the landings. A cover is then placed over a substrate to completely enclose the circuit board, as shown in FIG. 6b. It is anticipated that in some cases a cover might not be desired, in which case the step can be omitted. 
     The above described steps may be performed at a factory, while the following two steps may be performed in situ by the user. The enclosed terminator and the base are snapped together, sandwiching the cable and causing the contacts to penetrate the cable insulation to provide an electrical connection between conductors 12 and the circuit board, thus completing the assembly as shown in FIGS. 6(c) and 6(d). 
     Finally, in order to remove the termination circuit and move it to a different cable, the only steps necessary are unsnapping the base from the terminator, and clamping it onto another cable. This can easily be done by an ordinary user. 
     The foregoing description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and other modifications and variations may be possible in light of the above teachings. It is therefore intended that the appended claims be construed to include other alternative embodiments of the invention except insofar as limited by the prior art.