US3205295A

US3205295A - Electrical connector

Info

Publication number: US3205295A
Application number: US265782A
Authority: US
Inventors: James C Davidson
Original assignee: Burroughs Corp
Current assignee: Unisys Corp
Priority date: 1963-03-18
Filing date: 1963-03-18
Publication date: 1965-09-07
Anticipated expiration: 1982-09-07

Description

Sept. 7, 1965 J. c. DAVIDSON ELECTRICAL CONNECTOR 2 Sheets-Sheet 1 Filed March 8, 1963 WWO? 497' INVENTOR. JAMES 6'. MV/DSW/V p 7, 1965 J. c. DAVIDSON 3,205,295

ELECTRICAL CONNECTOR Filed March 18, 1963 2 Sheets-Sheet 2 INVENTOR. 1/44/55 6 DAV/06W its terminal point.

United States Patent Oflice 3,205,295 Patented Sept. 7, 1965 3,205,295 ELECTRICAL CONNECTOR James C. Davidson, Gicndora, Calif., assignor to Burroughs Corporation, Detroit, Mich., a corporation of Michigan Filed Mar. 18, 1963, Ser. No. 265,782 Claims. (Cl. 174-32) This invention relates to electrical connectors and more particularly to electrical connectors for the interconnection of twisted pair transmission lines.

When a plurality of conductors are placed in close proximity, there is a tendency for the signals travelling on one conductor to interfere with signals travelling on adjacent conductors. This interference is commonly called cross-talk and is especially noticeable and detrimental in high frequency circuits. One way to reduce the cross-talk is to entwine or twist the pair of conductors which constitute a transmission line. Thereafter, the twisted pair of conductors may be placed adjacent to each other without significant interference.

The twisted pair of transmission lines will usually terminate in a connector to form a cable for the interconnection between circuits. It is desirable to continue the twist or entwining of each pair of conductors down to its connection with the connector in order to avoid the cross-talk problem. In the past, the connectors have taken the form of a plurality of pins embedded in a layer of insulating material. Thereafter, two or more of the pins are interconnected by a conductor to form a terminal point for the ground conductors of the transmission line pairs. The signal conductors of each pair terminate at an individual pin. In such a construction, the ground conductors are all connected to a common point so that the twisting of a particular pair of conductors must be discontinued prior to the connection to the signal pin to provide sutficient length in the ground conductor to reach Thus, the problem of cross-talk is apparent.

However, another prior art connector overcame this problem of cross-talk by connecting the two conductors of each pair to adjacent pins on the connector. Thus, the twisting or entwining of the pairs could be continued down to the point of connection of each conductor. There is a big disadvantage in such a connector in that every other pin has a ground conductor connected thereto. This results in a highly inefiicient use of the pins that extend through the connector and of the available area in which the pins can be located.

Therefore, in accordance with the present invention, there is provided a connector which substantially overcomes the problem of cross-talk and provides a highly eflicient use of the pins or prongs of the connector. The connector includes a plurality of pins embedded in a layer of insulating material. In addition to the layer of insulating material there is provided a layer of conducting material on top of the insulating material. The pins are perpendicular to the surface of the layer of insulating material and extend away from the layer of conducting material. There is provided a plurality of holes or apertures in the layer of conducting material, with each hole being positioned directly above a pin in the layer of insulating material. Thereafter, a twisted pair of conductors advantageously have the twist extending down to the layer of conducting material, where the ground conductor is attached. Thereafter, the signal conductor is passed through an adjacent hole and connected to the pin located below the hole. Thus, the layer of conducting material effectively forms a finite ground plane or ground plate in the connector and substantially eliminates any cross-talk. Rather than having a plurality of pins of the connector associated with the ground conductors of the transmission lines, there may be as few as one pin associated with the ground conductors. This pin is electrically connected to the ground plate.

A particularly advantageous modification of the connector involves the extension of the pins associated with the signal conductors through the holes in the layer of conducting material so that the signal conductors may be more easily attached to the pins.

Thereafter, a further modification is particularly advantageous. Rigid conductors are attached to the layer of conducting material and extend above the surface thereof adjacent to one of the pins so that the ground conductor may also be more easily connected. Thus, the entwining or twisting of each pair may be continued down to the point of connection.

The above and other features and advantages of the present invention will be understood more clearly and fully upon consideration of the following specification and drawing in which:

FIG. 1 is a pictorial diagram of a prior art connector;

FIG. 2 is a pictorial diagram of another prior art connector;

FIG. 3 is a pictorial diagram of the connector in accordance with the invention;

further the understanding of the problems that existed in connectors for twisted pair transmission lines. The prior art connector of FIG. 1 is representative of one of the types previously employed to terminate twisted pairs of conductors. This particular type resulted in excessive cross-talk in that the twisting of the pairs had to be discontinued at some distance from the connection to permit sufiic'ient length for the ground conductor of each pair to be connected.

The connector 10f FIG. 1 includes a plurality of pins, of which only a few are shown, embedded in a layer of insulating material 3. 0f the pins embedded in the insulating material and extending therethrough, four are shown connected in common by a conductor 5. These four pins are separately numbered for identification purposes. For example, the pins that are connected together and are associated with the ground conductor of each pair through ground conductor 5 are pins 4. Onthe other hand, the pins that are associated with the signal conductor are pins 2.

A typical pair of transmission lines 6 includes a signal conductor 7 and a ground conductor 8. The signal conductor 7 is connected to a pin 2 and the ground conductor 8 is connected to the ground conductor 5, which is connected to the pins 4. It is seen that the twisting or entwining of the conductors must be discontinued a substantial distance from the connection to provide a sufiicient length of ground conductor 8 for connection to pins '4. Therefore, cross-talk becomes a problem in this prior art connector.

Another prior art connector, which overcomes this problem of cross-talk, permits the twisting of the conductors to continue down to the connection and is shown in FIG. 2. The connector comprises a layer of insulating material 11 and a plurality of pins 12. A typical twisted pair of conductors includes a signal conductor 13 and a ground conductor 14. The. two conductors of the pair are connected to adjacent pins so that every other pin 12 which extends through the layer of insulating material 11 will have a ground conductor attached thereto. This results in a very inefiicient use of the pins, that extend through the insulating material.

Now referring to FIG. 3, the improved electrical connector of the present invention will be described. The connector of FIG. 3 includes a laminated frame 21 which comprises a layer of insulating material 22and a layer of conducting material 23. A plurality of pins 24 are embedded in the layer of insulating material 22. These pins 24 are positioned perpendicular to the flat surface of the laminated frame 21 and, extend away from the layer of insulating material 22 on the side opposite the layer of conducting material 23. An aperture or hole 25 is located in the layer of insulating material 22 above each pin 24. Above each hole 25 is a coaxial hole 26 in the terial and a hole 25 in the layerof insulating material and makes contact with and is connected to one of the pins 24. This connection may be by a solder connection or any one of the other well-known ways of connecting electrical conductors to pins. The ground conductor 29 is connected to thelayerof conducting material 23 adjacent to the hole 26 through which its associated signal conductor passed. Every other twited pair of transmission ,lines will be similarly connected to the connector, i.e.,

the signal conductor will pass through the holes 26 and 25 to makecontact with a pin and the ground conductor thereto.

To complete the connector, the layer of conducting-material ;23,is electrically connected toone or more pins 30, so thatthe ground conductors of the transmission lines will be effectively connected to the circuit to which the connector is attached. Thus, as few as one pin may be associated with the ground or signal return conductors rather than having one-half of the pins required for ground conductors.

A preferred embodiment of the connector, in accordance with the invention, is shown in FIG. 4. This connector is similar to the connector of FIG. 3 and includes a laminated frame 21 which comprises a lamina of insulating material 22 and a lamina of conducting material 23. The pins 24, which are embedded in the laminaof insulating material, extend through holes 26 in the layer of conducting material 23. Thereafter, the signal conductor of ;the transmission lines may be more easily connected to .the pins above the finite groundplane or ground plate -formed by the layerof conducting material 23. Additionally, rigid conductors 31 are embedded in or con- .nected to the layer of conducting material 23 and extend above it so that the ground conductors of the transmission lines may also be more easily connected. The layer of conducting material 23 iselectrically connected to at least one pin 30 to carry all of the ground conductors or signal return conductors of the paired conductors into the next circuit.

A modification to the connector shownin FIG 4 is shown in FIG. 5. To the connector of FIG. 4 there is added a layer of insulating material 33 on top of the layer of conducting material 23. This is provided to more effectively isolate the pins 24 and the rigid conductors 31. Additionally, the layer of insulating material 33 will make the connector more rigid and durable.

After all of the conductors are connected to the connectors of FIGS. 3, 4 and S, the unit may be advantageously encased in a solid material, e. g., a plastic, to protect the electrical connections and the wires.

What is claimed is:

1. An electrical connector comprising a first layer of insulating material, a second layer of insulating material, a layer of conducting material sandwiched between the first and second layers of insulating material, a plurality of apertures located in the layer of conducting material and positioned in a spaced-apart relationship, a plurality of pins, each one of the pins extending through one of the apertures and embedded in the first layer of insulating material and the second layer of insulating material, the pins extending beyond the second layer of insulating material to form the prongs of the connector and extending in the opposite direction above the first layer of insulating material to form terminals for electrical conductors, rigid conductors embedded in the layer of conducting material and extending through the first layer of insulating material to form terminals for electrical conductors, and at least one pin embedded in the layer of conducting material and extending through the second layer of insulating material to form one of the prongs of the connector.

2. In combination, a layer of insulating material, a plurality of pins embedded in the layer of insulating material, a layer of conducting material positioned on top of the layer of insulating material, at least one of the pins being in electrical contact with the layer of conducting material, a plurality of paired transmission lines, each pair including a signal conductor and a signal return conductor, the signal conductor and the signal return conductor of each pair being intertwined, means for connecting each signal conductor to one of the pins, and means for physically connecting each signal return conductor to the layer of conducting material adjacent the pin of its associated signal conductor.

3. An electrical connector for twisted pair transmission lines comprising a layer of insulating material, a plurality of pins embedded in the insulating layer, a ground plate .through an aperture and connected to the pin therebelow,

the signal return conductor of each pair being connected to the ground plate adjacent to the aperture associated with the signal conductor of the pair, and at least one pin passing through the layer of insulating material and making electrical contact with the ground plate.

4. In combination, a layer of insulating material, a layer of conducting material attached to the layer of insulating material, a plurality of pins embedded in the layer of insulating material and positioned perpendicular to the plane of the layers, the pins extending away from the layer of insulating material to form the prongs of the connector and extending in the opposite direction above the layer of conducting material to form electrical terminals, a plurality of rigid conductors attached to the layer of conducting material and extending in a direction parallel to the plurality of pins above the layer of conducting material, a twisted pair of conductors connected to adjacent pins and rigid conductors so that the signal conductor will be coupled through the layers by the pins and the ground conductor will be coupled to the layer of conducting material by the rigid conductors, and at least one pin extending through the layer of insulating material from the layer .of conducting material and in contact with the layer of conducting material.

5. In combination, a laminated frame including a layer .of insulating material and a layer of conducting material,

a plurality of conductive pins embedded in the layer of insulating material, the pins positioned perpendicular to the laminated frame and extending away from the layer of insulating material on the side opposite the layer of conducting material, apertures in the conducting material above each pin, and a plurality of twisted pairs of conductors, the twist extending down to the layer of conducting material, one of the conductors of each pair extending through an aperture and connected to a pin, and the other conductor of each pair connected to the layer of conducting material adjacent to the aperture of its associated signal conductor, at least one pin being in electrical contact with the layer of conducting material.

References Cited by the Examiner UNITED STATES PATENTS Worthington.

Bowers 33918 Gauthier 339-14 XR Fett et al 17432 XR Jacobs 339-198 XR Trent.

10 DARRELL L. CLAY, Primary Examiner.

JOHN P. WILDMAN, JOHN F. BURNS, Examiners.

Claims

4. IN COMBINATION, A LAYER OF INSULATING MATERIAL, A LAYER OF CONDUCTING MATERIAL ATTACHED TO THE LAYER OF INSULATING MATERIAL, A PLURALITY OF PINS EMBEDDED IN THE LAYER OF INSULATING MATERIAL AND POSITIONED PERPENDICULAR TO THE PLANE OF THE LAYERS, THE PINS EXTENDING AWAY FROM THE LAYER OF INSULATING MATERIAL TO FORM THE PRONGS OF THE CONNECTOR AND EXTENDING IN THE OPPOSITE DIRECTION ABOVE THE LAYER OF CONDUCTING MATERIAL TO FORM ELECTRICAL TERMINALS, A PLURALITY OF RIGID CONDUCTORS ATTACHED TO THE LAYER OF CONDUCTING MATERIAL AND EXTENDING IN A DIRECTION PARALLEL TO THE PLURALITY OF PINS ABOVE THE LAYER OF CONDUCTING MATERIAL, A TWISTED PAIR OF CONDUCTGORS CONNECTED TO ADJACENT PINS AND RIGID CONDUCTORS SO THAT THE SIGNAL CONDUCTOR WILL