Shorting bar switch in electrical connector biasing assembly

Abstract

An improved electrical connector comprises a plurality of pairs of electrical contact members mounted in an insulative housing. The contacts of each pair are spaced apart to receive a prong of a printed circuit board. Those pairs of contacts which are to remain closed or "shorted" when the printed circuit board is removed from the connector structure are provided with shorting bar assemblies. Each shorting bar assembly comprises a shorting bar of electrically conductive material which is spring-biased into engagement with each contact of its associated mating pair. When a prong of a printed circuit board is inserted between the mating contacts it will depress the shorting bar, against the action of the spring, into a position which is out of contact with the contact members. When the prong of the printed circuit board is removed the spring of the shorting bar assembly returns the shorting bar to a position which again electrically connects or shorts the pair of mating contacts.

Description

FIELD OF THE INVENTION

The present invention relates to electrical connectors of the type which have a plurality of longitudinally spaced pairs of contacts embedded in a suitable insulative block. Such connectors are typically used, for example, in the tele-communications industry, for selectively electrically incorporating printed circuit boards in an electrical system (e.g., between data terminals or switching terminals in a telephone system).

BACKGROUND OF THE INVENTION

In various industries, such as the tele-communications industry, electrical connectors are required for electrically incorporating printed circuit boards between two sides of an electrical system (e.g., between data terminals, switching terminals, or the like). Such connectors must include a number of switches or contacts for connecting electrical wires from one side of a system to corresponding wires on the other side of the system. When a printed circuit board is inserted between the switches or contacts of such a connector the printed circuit board is incorporated in the system. When the printed circuit board is removed, some of the switches or contacts must remain closed and others must be opened.

One type of electrical connector which has been used in the past for fulfilling the foregoing functions comprised an elongated shell or housing of a suitable insulative material having a plurality of pairs of spaced contact members disposed therein. Each pair of contacts was adapted to receive a male prong or finger or portion thereof from a printed circuit board when such a circuit board was inserted into the connector. Since the contacts of each pair of contacts were normally spaced apart, when the printed circuit board was removed from the connector, it was necessary to insert a "jumper" board or a "dummy" board having conductive male prongs thereon which would extend between the contacts of the selected pairs of contacts which were to remain closed.

The foregoing type of electrical connector was not entirely satisfactory, efficient or economical because of the necessity of having to have numerous jumper boards having different prong arrangements at each site where the connector was employed.

A second type of connector for providing selective connection of printed circuit boards in electrical systems comprised a plurality of toggle switches, each of which was adapted to receive one of the prongs or prong portions of a printed circuit board. When the printed circuit board prongs were removed from the toggle switches, selected toggle switches were manually closed.

This second type of electrical connector structure was not entirely adequate, efficient or economical because of the necessity of having to manually close the selected toggle switches each time a printed circuit board was removed.

A third type of electrical connector structure for fulfilling the foregoing function of providing selective connection of printed circuit boards in electrical systems was designed in an attempt to obviate the problems of the two types of prior art connectors discussed above. This third type of connector structure was similar to the first type of connector structure discussed above in that it comprised an elongated housing of insulative material having a plurality of pairs of spaced female contact members embedded therein. However, in order to obviate the need for providing jumper boards for maintaining electrical connection between the contacts of selected pairs of contacts when the printed circuit board was removed from the connector, the selected pairs of female contacts were pre-stressed in the process of manufacture so that they would normally be biased into electrical contact with one another. Thus, when a printed circuit board was removed from such a connector the contacts of each selected pair would, theoretically, "spring back" into electrical contact with one another. This third type of prior art electrical connector was intended to eliminate the problems associated with the first two types of prior art connector structures described above; i.e., to eliminate the need for jumper boards and the need for manually closing the switches which were to remain closed when the printed circuit board was removed.

However, this third type of connector structure also proved to be inadequate in several respects. It was found that during the course of use some of the pairs of contacts were stressed beyond their elastic limits upon the insertion of the prong of a printed circuit board and, when the board was removed, these contacts did not spring back into contact with one another, thereby creating open circuit conditions and resultant problems in the electrical system in which the connector was incorporated. In addition, this third type of connector structure was relatively expensive due to the fact that the pre-stressed, normally closed prongs were made of a material different than the material used for the normally open contacts in the connector. Still further, the pre-stressing operation added to the manufacturing costs of the connector.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved electrical connector structure which obviates the disadvantages, discussed above, associated with the prior art connector structures while remaining the benefits of each.

It is a further object of the present invention to provide an electrical connector structure for the telecommunications industry and other industries which is more efficient, more reliable and more economical to manufacture and use than the prior art types of electrical connector structures.

The foregoing and other objects and advantages have been realized by the connector structure of the present invention which is of the type which has a plurality of mating pairs of electrical contact members embedded in an elongated housing of insulative material. All of the contact members (i.e., those pairs which are to remain open and those pairs which are to be electrically closed or shorted when a printed circuit board is removed therefrom) are manufactured of the same conductive material and are embedded in the insulative housing so that the contacts of each pair are spaced from one another. The shortest distance between the contacts of each pair is preferably somewhat less than the thickness or diameter of the printed circuit board prong or prong portion which is to be inserted therein, whereby the contacts, which are preferably made of a somewhat springy strip material, will grip the prong inserted therebetween. Those contact pairs which are to be shorted when the printed circuit board is removed from the connector are provided with a shorting bar assembly. The shorting bar assembly includes a shorting bar of electrically conductive material and means (e.g., a spring) to bias the shorting bar into electrical contact with each of the contact members of the pair with which the bar is associated. The shorting bar assembly is designed so that when the prong of a printed circuit board is inserted between mating contacts, the prong will depress the shorting bar and move it out of engagement with the contacts. When the printed circuit board prong is removed, the bias means will urge the shorting bar back into electrical contact with the pair of contacts to reestablish electrical connection.

Numerous other objects and advantages of the present invention will become apparent from a review of the following detailed description of a preferred embodiment of the present invention and the accompanying drawings thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a perspective view, partially broken away, of a preferred embodiment of an improved electrical connector structure constructed in accordance with the teachings of the present invention.

FIG. 2 is a sectional elevation view of the connector shown in FIG. 1, illustrating a pair of shorted contacts in the position occupied prior to the insertion of a prong of a printed circuit board.

FIG. 3 is a sectional elevation view similar to FIG. 2, illustrating the position of the contacts when a printed circuit board prong has been inserted.

FIG. 4 is a perspective view of one of the shorting bars employed in the connector structure shown in FIGS. 1-3, viewed from the underside thereof.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring now to the drawings, which depict a preferred embodiment of the improved connector structure 10 of the present invention, the connector 10 comprises an elongated block or housing 12 of insulative material. The interior of the housing 12 is divided into a plurality of upwardly opening cavities 14, 14 . . . 14 by inwardly extending wall sections or separators 16, 16 . . . 16 which are integrally formed on the housing 12.

The lower protion of the housing 12 is substantially closed by means of a longitudinal block 18 having a plurality of upwardly opening cavities 20, 20 . . . 20 therein.

Disposed within each of the cavities 14 in the connector block 12 is a pair of mating contact members 22, 22', each of which is forked at its upper end and twisted approximately 90.degree. approximately at the point 24 where it extends out of the bottom portion of the connector. Each pair of mating contacts 22, 22' is adapted to receive a prong or portion of a prong 26 of a printed circuit board (not shown). It may be noted that the upper forked portion of each of the contacts is bent inwardly as at 28, 28', so that the distance between the inwardly bent portions 28, 28' of the contacts 22, 22' is somewhat less than the thickness (or diameter) of the printed circuit board prong 26 inserted therebetween. This construction ensures that the contacts 22, 22' will make good electrical contact with the printed circuit board prong or prong portion 26. As noted earlier, it is desirable that selected pairs of the contacts 22, 22' be shorted when the printed circuit board prong 26 is removed from the connector 10. This is accomplished in the improved connector structure 10 by providing shorting bar assemblies 30 for each selected pair of contacts 22, 22' to be shorted.

As best shown in FIGS. 2 and 3, each shorting bar assembly 30 comprises a shorting bar 32 which is spring-biased upwardly into electrical contact with the two mating contact members 22, 22' by means of a compression spring 34.

As best shown in FIG. 4, the shorting bar 32 comprises a generally flat strip of conductive material which is bent into a U-shaped portion 36 in the center of the shorting bar. This U-shaped portion is designed to fit within the upper end of the compression spring 34. The lower end of the compression spring 34 fits within the cavity 20 in the elongated block 18 in the housing 12.

It will be noted that the outer ends 38, 38 of the shorting bar are bent downwardly at an angle approximately equal to the angle at which the contact members 22, 22' extend to provide greater assurance of electrical contact between the shorting bar 32 and the contacts 22, 22'.

In use, prior to the time that a printed circuit board prong or finger 26 is inserted into the connector 10, each of the mating pairs of prongs occupies the spaced apart position shown in FIG. 2. Each pair of contacts 22, 22' which is to remain shorted or in electrical contact with one another when the printed circuit board is removed is provided with one of the shorting bar assemblies 30. As shown in FIG. 2, the compression spring 34 of of the shorting bar assembly urges the shorting bar 32 upwardly so that the outer edges 38, 38 thereof contact the contact members 22, 22' to short them or establish electrical connection therebetween.

The other non-selected pairs of contacts 22, 22' (not shown) remain spaced apart to maintain an open circuit condition.

When the etched prong or finger 26 of a printed circuit board is inserted between a pair of the contact members 22, 22', it will initially spread the contacts apart slightly (see FIG. 3). Upon further insertion of the prong 26, the end of the prong will depress the shorting bar 32 downwardly, against the force of spring 34, into the enlarged space between the lower portions of the contacts 22, 22' (see FIG. 3).

When the printed circuit board prong 26 is removed from between the contacts 22, 22', the compression spring 34 will return the shorting bar 32 to the position shown in FIG. 2, wherein the shorting bar will again short the contacts 22, 22'.

The connector structure 10 may be manufactured relatively easily and inexpensively. The insulative housing 12, the contacts 22, 22', the shorting bar 32 and the compression spring 34 may all be individually fabricated. The shorting bar may be cut from a flat strip of suitable conductive material and formed in a suitable die. The shorting bar may be constructed of any suitable conductive material such as phosphor, bronze, berylium, copper, brass or the like.

The housing 12, contacts 22, 22', shorting bar 32 and spring 34 are assembled by first inserting the U-shaped central portion 36 of each shorting bar into the upper end of a compression spring 34, and thereafter inserting the bottom portion of the spring into one of the openings 20 in the insulative block 18 in the bottom of the housing 12. Thereafter, the contacts 22, 22' are inserted into place by first inserting a dummy board into the housing 12 to depress the shorting bars, and thereafter pulling the bottom ends of the contacts 22, 22' into place through the slots between the outer sidewalls of the block 18 and the inner sidewalls of the housing 12. Thereafter, the contacts 22, 22' may be twisted approximately 90.degree. at the bottom portions thereof (i.e., as at 24, FIG. 1).

From the foregoing it may readily be appreciated that the connector structure of the present invention attains all of the advantages of the prior art connectors discussed above, and obviates the disadvantages and problems thereof.

It is to be understood, of course, that the exemplary connector structure 10 shown in the drawings and described above constitutes only one preferred embodiment of the present invention. It is contemplated that numerous variations and changes may be made to the particular embodiment described and shown herein without departing from the spirit and scope of the invention. Accordingly, it is intended that this patent be limited only by the scope of the appended claims.

Claims

We claim:

1. In a printed circuit board connector assembly comprising an elongated body of insulative material having an elongated opening therein and a plurality of longitudinally spaced pairs of electrical contact members disposed in said elongated opening; each of said contact pairs comprising contacts spaced from one another and bent inwardly toward one another to define a space therebetween for receiving and making electrical contact with a portion of a circuit board inserted into said elongated opening in said elongated insulative body, the improvement comprising: a shorting bar assembly disposed between each of selected pairs of said contacts, said shorting bar assembly comprising a shorting bar of electrically conductive material disposed between said contact members; and spring means normally biasing said shorting bar into contact with each of said contact members to establish electrical connection therebetween; said shorting bar being movable to a position out of contact with said contact members to electrically disconnect said contact members from one another when a circuit board is inserted into said elongated opening in said elongated body of insulative material.

2. An improved electrical connector comprising: a housing of insulative material; a pair of mating contact members of electrically conductive material disposed in said housing for receiving a circuit member therebetween; said contact members having at least a portion thereof inclined toward one another to define a progressively decreasing space therebetween; and a shorting bar assembly disposed between said pair of mating contact members; said shorting bar assembly including a shorting bar of electrically conductive material disposed in said progressively decreasing space, and spring means biasing said shorting bar into electrical contact with a portion of each of said mating contact members; whereby, when a circuit member is inserted between said mating contact members said circuit member will first make electrical contact with said mating contact members, and, upon continued insertion of said circuit member, will depress said shorting bar out of electrical contact with said contact members to electrically disconnect said contact members and said shorting bar from one another.