BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to interface connec- tors for electrically connecting selected conductors o at least one input cable to selected conductors of at least one output cable, wherein said input and output -cables are terminated with multiple contact element, separable electrical connectors. The invention finds particular use in telephone distribution wiring where there is commonly a need to interconnect various cable which are terminated with dissimilar, i.e., non-mating, connectors. The specifically disclosed embodiment of the invention is designed, in particular, to intercon- nect a 25 pair, band marked distribution (BMD) cable, which is terminated with a female ribbon connector, with several telephone instruments, which each have cables terminated with modular plugs.

This invention further relates to eletrical connectors and, more particularly, to an electrical connector having doubly supported, bow-shaped contact elements which are each protected by a shroud. 2. Description of the Prior Art

It is common practice in the telephone indus- try to use 25 conductor pair, band marked distribution (BMD) cable in commercial installations where it is necessary to connect a large number of telephone devic¬ es to a central distribution box and where selective access must be had by each telephone device to a rela- tively large number of incoming telephone lines.

Typically, BMD cable is terminated with a so-called female ribbon connector, such as, the "Champ" manufac¬ tured by AMP, Inc. or the "Blue Ribbon" manufactured by A phenol Company.

Until recently, it had also been a standard practice to terminate the cable of each telephone instrument, or keyset, with a mating, male ribbon connector with the instrument cable being connected only to those contact elements in the connector needed to pick up the desired telephone lines.

For a variety of reasons, most prominently the need to curtail the rising cost of skilled labor, but also in order to reduce the actual cost of the connectors themselves, most telephone companies are today endeavoring to equip substantially all new telephone instruments, including multiple line keysets, with so-called modular plugs rather than the connectors used in the past. The production of keyset telephone instruments having modular plugs presents an obvious problem where installation is required in a building which is wired with BMD cable terminated with ribbon connectors; the two connector types are non-mating.

The use of modular plugs has, accordingly, spawned the need for interface connectors which are able to mate both with the ribbon connectors used to terminate BMD cable and with the modular plugs used on the telephone instruments. All such devices will, of necessity, comprise at least one male ribbon connector of the known per se variety and at least one modular receptacle, also of the known per se variety. Means, of one sort or another, must also be provided within the interface connector for electrically connecting selected contact elements of the ribbon connectors to selected contact elements of the modular receptacles.

It is in this last regard that most, if not all, prior art interface connectors have exhibited a rather severe shortcoming; that is, discrete wire conductors have been used to make the required internal connections within the interface. The use of such internal hard wiring in a connector is undesirable for

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several reasons. First, connector assembly where hard wiring is involved is labor intensive and connectors so produced must be priced accordingly. In addition, the use of manual assembly, which is almost certainly required to produce a hard wired connector, introduces the possibility of assembler error. And, finally, har wired interface connectors cannot achieve the degree o compactness which is often desired.

From the above discussion, it should be evi- dent that there exists a great need for an improved interface connector which does not make use of internal hard wiring. The present invention fulfills this need.

A number of known per se separable electrical connectors utilize spring loaded contact elements which have a generally bowed or arched configuration and which are retained in a connector housing so as to function as doubly supported beam structures. Such contact elements may be found in either plug or recep- tacle connector housings and are adapted for sliding or wiping electrical engagement with corresponding contact elements in complementary connector housings. The contact elements found in most so-called "ribbon" connectors are exemplary of the type referred to. Experience with connectors of the above- described variety has, to some extent, proven unsatis¬ factory, because the contact elements of many designs are susceptible to mechanical damage. Such damage to the contact elements may occur, for example, through the improper mating of connector parts or through the improper insertion of tools and the like into the connector. A bent or otherwise damaged contact element will, of course, render the connector useless.

OBJECTS OF THE INVENTION Accordingly, it is one object of this inven¬ tion to provide an improved interface connector which overcomes the above disadvantages. It is another object of this invention to pro vide an electrical connector having doubly supported, bow-shaped contact elements which are protected from mechanical damage.

It is a further object of the invention to provide an electrical connector having protected con¬ tact elements wherein the means for protecting said contact elements do not alter the desirable mechanical properties thereof.

And it is a further object of the invention to provide a connector having such contact protection means which is, nonetheless, compatible and able to mate with known per se connectors.

SUMMARY OF THE INVENTION In accordance with one form of the present invention, there is provided an interface connector which comprises at least one connector means for making separable electrical connection to a female ribbon connector and at least one connector means for making separable electrical connection to a modular plug. The contact elements of these connector means are directly connected, as by soldering, to a common printed circuit board. Conductive paths on the board are provided for making the desired interconnections between contact elements in the two types of connector means. An in- sulating housing contains the printed circuit board and preferably also incorporates both types of connector means as integral portions thereof.

In accordance with another form of the inven¬ tion, there is provided a separable electrical connec- tor which includes at least one resilient electrical contact element having a generally bowed or arched

portion intermediate its two ends. The two ends of the contact element are retained against a backer surface in the connector housing so that the contact functions as a doubly supported beam structure. A forward end of the contact is protected from mechanical damage by a shroud which is molded into the connector housing.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a drawing depicting the interface connector of the invention in the environment of its intended use, connected, at its input side, to a BMD cable terminated with a ribbon connector and, at its output side, to a telephone instrument equipped with a modular plug.

Figure 2 is an exploded, isometric view of the interface connector according to the invention.

Figure 3 is front, plan view of the interface connector according to one form of the invention.

Figure 3' is front, plan view of the inter¬ face connector according to another form of the invention.

Figure 4 is a rear, plan view of the inter¬ face connector according to one form of the invention. Figure 4' is a rear, plan view of the inter¬ face connector according to another form of the invention.

Figure 5 is a partial view, from one end, of the interface connector according to one form of the invention.

Figure 5* is a partial view, from one end, of the interface connector according to another form of the invention.

Figures 6, 7 and 8 depict a novel contact element used in the interface connector.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Turning first to Figure 1, the interface connector 10 provided by the invention is depicted in its intended environment of use. An input, 25 conductor pair, BMD cable 11, coming from a central distribution box, not shown, is terminated with a female ribbon connector 12 of the known per se variety. An output cable 15, having eight conductors, leads to a telephone instrument, not shown, which is to be connected into the system. Cable 15 is terminated with a modular plug 16 of the known per se variety. The interface 10 is provided on one side with a male ribbon connector 17, which mates with the female 12, and on the other side with six modular receptacles 13a-13f, each of which is adapted to receive a plug such as 16. It will be noted that, when assembled as shown, the combination of ribbon connector, interface and modular plug possesses an in-line or 180" configuration. Figures 2 through 5 illustrate the construction of interface 10. The connector comprises a printed circuit board 20 to which there is affixed, on one side, an input array 21 which includes forty- eight to fifty electrical contact elements 22. Each contact element 22 is retained by the board by press fit insertion of a tail portion thereof into a plated through hole 23 in the board followed by heating to reflow the solder, in a manner well known in the art. The contact elements 22 in the input array 21 are suitably arranged for making electrical contact with corresponding contact elements of the female ribbon connector 12 which terminates the input cable 11.

To the other side of the printed circuit board 20, there are affixed six output arrays, 24a through 24f, of wire spring electrical contact elements 25. Each of the contact elements 25 is also retained by the board by press fit insertion of a tail portion thereof into a plated through hole 26 in the board

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followed by heating to reflow the solder. The contact elements 25 in each of the arrays 25a through 25f are suitably arranged for making electrical contact with corresponding contact elements of a modular plug, such as 16, terminating an output cable, such as 15.

A plurality of plated, conductive paths 27 (only a few of which are shown) are provided on both sides of the printed circuit board 20 for electrically interconnecting preselected contact elements 22 in the input array 21 to preselected contact elements 25 in the output arrays 24a through 24f.

The precise interconnections to be thus made by the conductive paths 27 will, of course, be a matter of design choice. For example, in an interface wherein each output array comprises eight contact elements, as in the embodiment shown, it might be desired to connect the eight contact elements in output array 24a to a first group of eight contact elements in the input array 21, the eight contact elements in output array 24b to a second group of eight contact elements in the input array, and so on. In this way, each of the arrays 24a through 24b will provide access to different groups of telephone lines. As an alternative, the contact elements in all six output arrays may be be connected to a single group of contact elements in the input array. This scheme would permit the connec¬ tion of six telephone instruments to the same group of telephone lines.

An insulating housing contains the printed circuit board 20, together with the electrical contact elements 22 and 25 which are affixed thereto. Prefer¬ ably, the housing comprises two housing portions 29 and 30 which are adapted to fit together, as shown, to form the whole. As depicted in Figure 3, the housing portion

29 includes exterior embossments 31a and 31b which

together constitute an embossment which is a mating surface for a female ribbon connector. The electrical contact elements 22 extend through openings 40 in housing portion 29 and are positioned upon the embossment 31b in a standard male ribbon connector array.

As shown in Figure 4, the housing portion 30 comprises the six modular receptacles, 13a through 13f, each of which is an aperture appropriately dimensioned to receive a modular plug, such as the plug 16. As shown in Figure 5, each of the receptacles 13a through 13f has a first end 34 located at the face 33 and a second end 35 opposite thereto which is located within the interface interior. An internal floor member 36 runs between the ends 34 and 35 of each receptacle.

In the assembled interface, the printed circuit board 20 forms a rear wall of each of the plug receiving receptacles, 13a through 13f, located at the second ends 35 thereof. The electrical contact ele- ments 25 in each of the output arrays, 24a through 24f, extend from the printed circuit board 20 into the respective receptacles 13a through 13f, running from the second ends 35 of the apertures toward the first ends 34. In each receptacle, the wire spring contacts 25 are positioned upon the internal floor member 36 and are maintained in a spaced-apar , side-by-side relation¬ ship by a comb 37 on the floor member. An arched portion 38 intermediate the two ends of each of the contacts 25 is provided for making electrical contact with a corresponding contact element of a modular plug.

As will be readily appreciated by those skilled in the connector art, the two housing portions 29 and 30 may be securely assembled by any of a variety of means, including gluing or ultrasonic welding.

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The present invention is regarded to be, most broadly, an interface for connecting selected conductors of at least one input cable to selected conductors of at least one output cable wherein said input and output cables are each terminated with a multiple contact element, separable electrical connec¬ tor and wherein the interface relies on an internal printed circuitry rather than hard wiring.

While the interface of the disclosed e bodi- ment is adapted to connect together input and output cables which are terminated with ribbon connectors and modular plugs, respectively, the use of such termina¬ tion in the disclosed embodiment should not be con¬ strued as limiting. Obviously, an interface according to the invention may be constructed for use with input and output cables which are terminated with other connector types.

Similarly, while a printed circuit board is utilized in the disclosed embodiment, printed circuitry, including flexible printed circuitry, may in general be used.

Figures 3', 4' and 5* illustrate an alter¬ native construction of interface 10. The connector comprises a printed circuit board 20 to which there is affixed, on one side, an input array 21 which includes, more or less, fifty resilient electrical contact elements 22'. Each contact element 22' is retained by the board by press fit insertion of a tail portion thereof into a plated through hole 23 in the board followed by heating to reflow the solder, in a manner well known in the art. If the contact elements 22' are fabricated of sheet metal stock, however, it is pre¬ ferred to use the novel press fit configuration de¬ picted in Figures 6, 7 and 8. In this novel configura- tion, the tail 70 of the contact 22* is stamped so that it has generally "V" shaped cross section wherein the

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legs 71 and 72 of the V are initially spread so as t be slightly wider than the diameter of the platted through hole 23. The contact tail has a bevel 73 wh facilitates insertion of the tail into the hole. As the tail is so inserted, the V configuration resilie ly folds together slightly so that the edges 74 and are urged to bite into the platting 76 lining the ho The contact elements 22* in the input array 21 are suitably arranged for making electrical contact with corresponding contact elements of the female ribbon connector 12 which terminates the input cable 11.

To the other side of the printed circuit board 20, there are affixed six output arrays, 24a through 24f, of resilient electrical contact element 25*. Each of the contact elements 25' is also retai by the board by press fit insertion of a tail portio thereof into a plated through hole 26 in the board followed by heating to reflow the solder. The contac elements 25* in each of the arrays 25a through 25f a suitably arranged for making electrical contact with corresponding contact elements of a modular plug, su as 16, terminating an output cable, such as 15.

A plurality of plated, conductive paths 27 (only a few of which are shown) are provided on both sides of the printed circuit board 20 for electrical interconnecting preselected contact elements 22* in input array 21 to preselected contact elements 25' i the output arrays 24a through 24f.

An insulating housing contains the printed circuit board 20, together with the electrical conta elements 22* and 25' which are affixed thereto. Preferably, the housing comprises two housing portio 29 and 30 which are adapted to fit together, as show to form the whole. As depicted in Figure 3, the housing porti

29 includes exterior embossments 31a' through 31b*

which together constitute an embossment which is a mating surface for a female ribbon connector. The electrical contact elements 22' extend through opening 40 in housing portion 29 and are positioned upon the embossment 31b' in a standard male ribbon connector array.

As shown in Figure 4, the housing portion 30 comprises the six modular receptacles, 13a through 13f each of which is an aperture appropriately dimensioned - to receive a modular plug, such as the plug 16. As shown in Figure 5, each of the receptacles 13a through 13f has a first end 34 located at the face 33 and a second end 35 opposite thereto which is located within the interface interior. An internal backer surface 36 runs between the ends 34 and 35 of each receptacle.

In the assembled interface, the printed circuit board 20 forms a rear wall of each of the plug receivcing receptacles, 13a through 13f, located at th second ends 35 thereof. The electrical contact ele- ments 25' in each of the output arrays, 24a through

24f, extend from the printed circuit board 20 into the respective receptacles 13a through 13f, running from the second ends 35 of the apertures toward the first ends 34. In each receptacle, the resilient contacts 25' are positioned upon the internal backer surface 36 and are maintained in a spaced-apart, side-by-side relationship by a comb 37 on the floor member. An arched portion 38 intermediate the two ends of each of the contacts 25' is provided for making sliding or wiping electrical contact with a corresponding contact element of a modular plug and for lending resilience to the contact element. Because each contact is supported at both of its two ends, 50 and 51, by the backer surface 36, the contacts function as doubly supported beam structures and are, consequently, fairly rigid.

An overhang 52 is provided for enshrouding the end 50 of the contact element 25'. Overhang 52 protects the contact element 25' from mechanical damage by not allowing the end 50 to be lifted and bent back by an object entering the connector (for example, an¬ other connector or a tool). At the same time, however, it will be noted that the overhang 52 permits entry of the plug 16 into the receptacle.

It will be further noted that a clearance space 53 is provided under the overhang. The space 53 permits expansion of the contact 25' in the direction X.^ when the contact in plug 16 exerts a mating force F^.

On the ribbon connector side of the inter- face, it will be noted that resilient contact element 22' also comprises an arched or bowed portion 54 intermediate its two ends 55 and 56. The arched portion is adapted to slidingly or wipingly engage a corresponding contact element in the female ribbon connector 12 and, also, provides resilience for the contact element 22*. A backer surface 57 of the embossment 31 (b)' supports the ends 55 and 56 of the contact element 22 so that the element functions as a relatively rigid doubly supported beam structure. Overhangs 58 are provided on the end of the male embossment 31b' to shroud and protect the ends of the contact elements 22*, in the same way that the overhang 52 protects the contact element 25*. Once again, clearance spaces 59 are provided under the overhangs 58 to allow expansion of the contact elements 22' in the direction X ₂ in response to the mating force F ₂ . It will be noted that the overhangs 38 do not interfere with the mating of the male and female ribbon connectors. From the foregoing description of the embodiments of the invention, it will be apparent that

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changes and modifications in construction obvious to those skilled in the art which do not depart from the scope of the invention are intended by the appended claims to be covered.

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