Electrical Connector Assembly

Abstract

An electrical connector assembly which includes an insulator housing having a pair of parallel rows of openings passing from a front face to a back face thereof. The openings are adapted to receive terminal contacts which lock in place. The locking means between the terminal contacts and the housing are available for unlocking through adjacent access means from the top and bottom surfaces of the housing. A flat thin extension extends from the back face of the housing between the rows of the pair of rows of openings. Clamp means are provided on each side of the extension to provide a strain relief for the wires to which the contacts are attached. The clamp means also serve as a common grounding conductor.

Description

This invention relates to electrical connector assemblies and more particularly to an electrical connector assembly for terminating electrical wires to printed circuit cards.

One of the limiting factors in the use of printed circuits is the number of electrical connections that can be made thereto. The usual way of connecting electrical wires to circuits on a printed circuit board is to use an auxiliary board to which the wires are soldered at plated through holes. These plated through holes are connected to edge contacts by means of printed circuitry. The edge contacts are in special connector assemblies which are adapted to be plugged into receptacles containing conductor pins to which the printed circuitry on the printed boards are terminated. The problem with this technique for making the electrical connections is that any change in the circuitry requires removing the wire by unsoldering the joint and making a further solder joint at some other point on the auxiliary board. This might also require a change in the printed circuitry on the auxiliary board which connects the solder points to the edge contacts. In any event, it will be appreciated that the density of the connections is seriously limited as well as the circuit changeability once the connections are made. The problem with the soldered connections has been solved by means of an electrical connector assembly as shown in U.S. Pat. No. 3,215,975 issued Nov. 2, 1965 which shows terminal contacts attached to wires and inserted into a housing which is adapted to plug into a mating unit attached to a printed board. It will be appreciated, however, that the connections are not readily interchangeable since the electrical contacts are locked into place.

Accordingly, it is an object of the present invention to provide a connector assembly in which the terminal contacts can be readily unlocked for removal.

It is another object of the present invention to provide a connector assembly in which the electrical contacts can be unlocked and removed without removing the connector assembly from a plugged in position. Thus an individual electrical connection can be broken without interrupting any other electrical connection made through the connector assembly.

It is a further object of the present invention to provide a connector assembly in which a strain relief is provided for the wiring which further facilitates the ease by means of which the electrical connectors are inserted and removed from the connector assembly.

It is another object of the present invention to provide a connector assembly in which a common grounding means is provided in conjunction with the strain relief.

It is further object of the present invention to provide means by which the contacts can be more easily inserted into the openings of the housing.

It is another object of the present invention to provide guide means which prevent the wrong orientation of the connector assembly with its mating connector pin assembly and which provides positive guiding and plugging.

Briefly, the invention consists of an electrical connector assembly for terminating electrical wires to circuit cards via a socket-pin arrangement. The assembly includes an insulator housing having a pair of parallel rows of openings passing from a front face to a back face of the housing. Access means are provided on the top and bottom of the housing so that access to a respective one of the openings in the adjacent row of openings can be made. These access means provide a means for unlocking electrical contacts located in the respective openings thereby freeing the electrical contacts for removal from the opening.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings.

FIG. 1 is an isometric view of the assembled connector assembly.

FIG. 2 is an isometric exploded view of the assembly of FIG. 1.

FIG. 3 is a cross-sectional view taken along the lines 3-3 of FIG. 1 showing the contacts locked into the assembly.

The electrical connector assembly consists of a housing 10 made of an electrically insulative material. The housing is preferably made of a one piece molded plastic construction. The front face 12 of the housing has two parallel rows of openings 14 therein. The openings 14 are spaced close to each other and pass through the housing 10 to the back face 16 thereof. The upper row of openings 14 in the housing 10 intersects with access openings 18 which extend from the top surface 20 of the housing 10 to the top row of openings 14. There are the same number of access openings as openings 14 in the top row so that access may be had to each of the top row openings 14 from a respective access opening 18. The same arrangement exists for the bottom row of openings 14, the only difference being that the access openings 18 extend from the bottom surface 22 of the housing as oriented in FIGS. 1 and 2. The housing 10 has thin flat extension 24 extending at right angles from the back surface 16 of the housing 10 between the upper and lower row of openings 14. A guide element 25 extends along each side of the extension. These guide elements 25 are parallel to one another and each contains a parallel groove 26 which is offset from the extension 24 by the same amount and in the same direction. The grooves are adapted to receive a respective guide finger which extends from the socket to which the connector assembly is to be mated. These grooves serve to prevent insertion of the connector assembly into its mating element with the wrong orientation. It is also serves to guide the connector element into positive mating relationship with the pins or other elements to which it connects.

The wires 28 which are to be terminated or connected by means of the connector assembly have electrical contacts 30 attached thereto. The contacts 30 shown in FIG. 3 correspond to the serpentine contact described in U.S. Pat. No. 3,208,030. The contact element or terminal 30 is shown as formed from a single elongated flat strip of metal such as spring stock of copper alloy or Phosphor bronze. For ease of description the terminal strip may be described as comprising a contact engaging front end portion or bellows 36 terminating with an end spring leaf 37, a conductor-connecting rear end portion 38 terminating with an end pair of wings 39, and a middle portion 40 between said end portions.

A conductor retaining pair of sides 41 is formed by bending the side edges of the terminal strip toward each other to provide a well for solder or a confined spot wherein the end of the wire 28 may be welded onto the contact. This inner bend is continued to form the wings 39 which are to be crimped around the outside surface of an insulation jacket or coating of the wire signal conductor 28. Thus a conductor wire is secured both mechanically and electrically in a strong fashion to the rear end of a contact 30. The openings 14 in the housing member 10 are designed to hold the contact 30 inserted therein in position tightly and securely against accidental loosening or withdrawing. For such securance, the middle portion 40 of the contact 30 has a spring retainer or stop finger 32 struck from it leaving an opening in the strip. The strip finger 32 extends longitudinally with respect to the strip contact 30 with that end of the finger 32 which is remote from the conductor wire 28 end portion of the strip, integral with the strip, while the other end of the finger is free. Thus the finger 32 may be pressed toward or partially into its opening, as when the contact strip 30 is being inserted into the insulation housing 10 and then the finger will spring outwardly, when free of housing hole restraint, to the position shown in FIG. 3 whereby the end of the finger engages the back wall 42 of the access opening 18 from the adjacent surface of the housing 10 to prevent withdrawal of the terminal contact 30 from the housing. It is relatively simple to remove the contacts 30 from the openings 14 in the housing 10 by depressing the finger 32 which engages the backwall 42 of the excess opening 18 through the access opening which is available for such a function. The depressing of the spring material finger 32 can be done either manually or with a tool of some type. In any event, the depressing of the spring finger 32 essentially unlocks the terminal contact 30 so that it can be easily removed. The easy insertion and removal provides a very flexible wiring arrangement so that any desired changes can be made. The insertion of the terminal contacts 30 into the openings 14 through the back face 16 of the housing 10 has been further facilitated by locating a loading shelf 44 contiguous with the inner surface of the openings 14 at the back face 16 of the housing 10. The shelf 44 extends a short distance at right angles to the back surface 16 of the housing thereby allowing the ends of the spring leafs 37 of the contacts 30 to be located thereon, and then with a slight pressure the terminal contact 30 can be guided directly into its housing opening 14.

A clamping bar 46 is attached to the outer end on both sides of the flat extension 24. These bars 46 are utilized to clamp the wires 28 which are plugged into the respective row of holes in the connector member 10. The clamping bar 46 is shown attached by screws on either side of the extension 24 in FIG. 2. Thus, the strain point where the contact 30 is connected to the wire 28 is moved to the clamp 46 at the outer portion of the extension 24. The strain relief clamp 46 is located at a sufficient distance from the housing 10 such that the terminal contacts 30 can be readily inserted and removed from the housing without any interference from the clamp.

The connector assembly can also be used to terminate coaxial wires 60. When using coaxial wire 60, the serpent contact 30 is connected to the inner conductor and the portion of the wire which is contacted by the clamping bar 46 has the outer coaxial conductor insulation removed so that the clamping bar 46 contacts the ground shield 62. In order to insure good electrical connection between the clamping bar 46 and the coaxial shield 62, the coaxial shield 62 is tin-plated 64 and the facing surfaces of the clamping bar are also tin-plated 66. The tin to tin contact makes a much better electrical connection between the shields 62 and the clamp 64 and provides a good electrical conductor along the surface of the clamping bar 46. A common ground connection 68 for all the coaxial wires extends from the tin plated conductor 66 of the bar 46 to a grounding connection. In this case, the common ground wire 68 terminates in a ground contact 30 in the connector assembly. Thus, in addition to the strain relief provided by the clamping bars 46 a common ground means is provided for coaxial wires.

To prevent the possibility of shorting between contact terminals at the openings 14 in the back surface 16 of the housing 10, a pair of separator elements 48 made of the insulative material such as plastic are provided. These elements 48 have a flat outer surface and are made to fit into the area defined by the back surface 16 of the housing 10, the guide elements 25 and the outer end of the thin flat extension 24. A number of insulator projections 50 extend at right angles from the facing surfaces of the elements 48 at the end abutting the back surface 16 of the housing 10. These insulator projections 50 are parallel to the side edges of the elements 48 and extend a short distance from the housing back surface 16. The insulator projections 50 are spaced with respect to one another so that they form separators between the openings 14 in the respective row of openings in the back surface of the housing 10. Each separator element 48 is attached to its respective side of the thin flat extension 24 by the same screws 52 which attach the clamping bars 46 thereto. These insulator elements 48 not only prevent shorting between contacts 30 but provide a protective housing extension for the connector and a readily available handling area for inserting and removing the connector assembly from its mating receptacle.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims

I claim:

1. An electrical connector assembly comprising:

an insulator housing have a pair of parallel rows of openings passing from a front face to a back face of said housing;

a plurality of access means in the top and bottom surfaces of said housing each providing access to a respective one of said openings of the adjacent row of said openings;

terminal contacts adapted for insertion in each of said openings of said pair of rows of openings;

locking means for locking each of said terminal contacts in its respective openings, said locking means being releasable through said access means thereby freeing said terminal contacts for removal from said openings;

an extension extending from the back face of said housing between said rows of said pair of rows of openings; and

clamp means for clamping wires attached to said terminal contacts to a respective side of said extension thereby moving the strain point from the connection point between the wire and terminal contact at the opening in the back face of said housing to said clamp means.

2. An electrical connector assembly according to claim 1, wherein said clamp means is located on said extension at sufficient distance from the back face of said housing to allow easy insertion and withdrawal of said terminal contacts into and out of said openings through the back face of said housing.

3. An electrical connector assembly according to claim 1, wherein said wires are coaxial wires;

said clamp means being an electrical conductor contacting the ground plane shield of said coaxial cable; and

a common grounding connection extending from said conductive clamp means to a terminal contact within said connector housing.

4. An electrical connector assembly according to claim 3, wherein said clamping means comprises a clamp bar attachable to said extension having tin plating along the surface of the clamp bar which contacts the wires to provide a good conducting surface; and

tin plating on the portion on the ground plane shield of said coaxial wire contacted by said clamp bar so that a good electrical connection is made between said clamp bar and said ground plane shield of said coaxial wire.

5. An electrical connector assembly according to claim 1, wherein a shelf is provided extending a short distance from the back face of said housing contiguous with the inner surface of said openings so that the spring leaf of the terminal contact can be placed thereon as a guide means for easy insertion into said opening.