Connector device having serially disposed pretensioned contacts

BACKGROUND OF THE INVENTION

This invention relates to connector devices having terminals for making electrical connection with plug-in devices such as printed circuit boards and, in particular, pertains to those devices in which the terminals are pretensioned.

When electrical connections are made between terminals in a connector and an inserted structure such as a printed circuit board, the terminal must exert sufficient contact force to insure good electrical continuity between the appropriate contacting parts. Conventionally, the typical terminal connector uses a spring contact to generate contact force. Contact force, in turn, is proportional to the amount the spring contact is deflected. It follows, therefore, that in order to obtain reasonably high levels of contact force, the spring contact must either have a large deflection or it must be pretensioned. On the whole, the latter arrangement is generally the most desirable, because it requires the least amount of space and thereby results in smaller devices.

While small size is a worthwhile, if not essential, result, it is also desirable that connector devices be inexpensive and electrically efficient.

Accordingly, one object of this invention is to simplify the construction of connector devices while insuring that good electrical contact will be made between the components being connected.

SUMMARY OF THE INVENTION

In accordance with one embodiment of this invention, the connector device comprises a terminal member and a support block wherein the terminal member includes a contact end pretensioned to exert a force against an inserted component, and the support block includes an aperture to accommodate an inserted plug-in type device and at least one terminal pocket for accommodating the terminal member and for pretensioning the contact end thereof.

According to one feature of this invention, the terminal member is a unitary structure comprising two end sections, a base section, a contact section and two raised contacts wherein the raised contacts are mounted on the contact section in line with each other, and the end sections cooperate with the base section to impart a pretensioning bias to the contact section when the terminal member is inserted in a terminal pocket.

According to another feature of this invention, the two raised contacts are mounted in line with each other on different portions of the contact section, each portion of the contact section is separated from the other by a space, and each end section is attached to the base section at one end and attached to one portion of the contact section at the other end.

According to another feature of this invention, the portions of the contact section containing the raised contacts join each other at one end and an end section at the other end. According to another feature of this invention, the portions of the contact section containing the raised contacts join each other at one end and an end section at the other end.

According to another feature of this invention, each terminal pocket comprises an inner wall and two parallel flanges separated by a slot wherein the slot accommodates the raised contacts of a terminal member and the inner wall and parallel flanges cooperate with the contact section to establish a pretensioning bias in the end sections.

The foregoing objects and features of this invention, as well as others not specifically set forth, will be better understood by reference to the drawing and the following detailed description.

DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective view of a terminal member;

FIG. 2 is a perspective view of a terminal member of alternate construction;

FIG. 3 is a partial view of an end elevation of a terminal member and a support block combined to form a connector 5 device; and

FIG. 4 is a section view taken in elevation along the line 4— 4 of the connector device shown in FIG. 3.

DETAILED DESCRIPTION ’θ Referring to FIG. 3, a connector device 10 is shown which comprises a support block 20 and a terminal member 30. As illustrated in FIG. 4, the connector assembly 10 functions as a socket for a plug-in component such as a printed circuit board 15 40. Specifically, the printed circuit board 40 includes electrical conductor paths 41 which engage the terminal member 30 when printed circuit board 40 is inserted in the connector device 10.

The support block 20 is advantageously made of a rigid in20 sulating plastic and is conveniently rectangular in shape. As illustrated in FIGS. 3 and 4, the center contains a hollowed out portion conveniently molded into the support block 20 and comprising a central socket opening 23 and a number of termini pockets 24. The socket opening 23 is designed to ac25 commodate an inserted printed circuit board and accordingly is conveniently rectangular in shape. Each terminal pocket 24 accommodates a portion of a terminal member 30.

The embodiment illustrated in FIG. 3 is a double-sided connector. Thus, the terminal pockets 24 are disposed on opposite sides of the socket opening 23. In a single-sided connector, on the other hand, the terminal pockets 24 will be disposed on only one side of the socket opening 23. Each terminal pocket 24 contains a slot 25, two flanges 26, a hole 27, 25 an inner wall 28 and a groove 29. The slot 25 is located between the two flanges 26 and extends to the bottom of the socket opening 23. The hole 27 is located adjacent to the inner wall 28 and extends to the outside of the support block 20. The groove 29 extends only part way into the socket operi40 ing 23. Moreover, the depth each groove 29 extends into the socket opening 23 advantageously differs in adjacent terminal pockets 24 for reasons explained elsewhere. Finally, each hole 27 is designed to accommodate one portion of a terminal member 30, while the inner wall 28 functions as a support or 45 base for another portion.

As best seen in FIGS. 1 and 2, each terminal member 30 comprises a contact end 31 and a terminal endi 32. Two versions of the terminal member 30 are shown in FIGS. 1 and 2, respectively, and, in the version shown in FIG. 1, the contact 50 end 31 includes a portion of a terminal blade 34 and a unitary contact structure made of a resilient material such as phosphorous bronze or beryllium copper. The unitary contact structure comprises a base section 35, two end sections 36, a contact section 37 divided into two portions, and two raised 55 contacts 38. The base section 35 is rigidly attached, as by welding, to the terminal blade 34, the two portions of the contact section 37 each contain one of the raised contacts 38, and the end sections 36 join the base section 35 and the contact section 37 so that a bias will be imparted to the contact section 37 when the contact section 37 is constrained between the inner wall 28 and the flanges 26 in the support block 20.

As shown in FIG. 1, the terminal end 32 of the terminal member 30 is formed as a part of the terminal blade 34. Ad65 vantageously, it is rectangular in cross section to facilitate connection by the use of wire wrapping apparatus. Moreover, it includes a locating tab 39 which can be projected outwardly from the surface thereof.

Each terminal member 30 is assembled in the support block 70 20 by pushing the terminal end 32 through the hole 27, deflecting the end sections 36 and inserting the terminal member 30 until the locating tab 39 engages the support block 20. The end sections 36 are deflected to allow the contact section 37 to be squeezed into a terminal pocket 2A where it is 75 held under tension or “pretensioned” by the flanges 26 and

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4 the inner wall 28. As can be seen from FIGS. 3 and 4, when the terminal member 30 is in place, the contacts 38 are serially disposed in the slot 25 and project into the socket opening 23. After the terminal member 30 has been inserted in the support block 20, it can be held in place by dimpling the terminal end 32 at an appropriate point (not shown).

Either version of the terminal member 30 performs satisfactorily. The one shown in FIG. 2, however, may permit manufacturing efficiencies. Specifically, the contact end 31 and the terminal end 32 are both part of a single unitary structure. As shown in FIG. 2, however, one end 36 does not fixedly attach to the terminal blade 34. As a result, the end sections 36 can separate when the contact section 37 is depressed during insertion into a terminal pocket 24. Furthermore, the locating tab 39 is designed to slide in the groove 29 so as to limit the distance the terminal member 30 can be inserted. Since, as described earlier, the grooves 29 in adjacent terminal pockets 24 are staggered, the terminal members 30 will be staggered with respect to each other when inserted.

When a printed circuit board 40, as, shown in FIG. 4, is inserted into the socket opening 23, the electrical path 41 engage the contacts 38 and further deflect the end sections 36. Since the force needed to deflect the end sections 36 must overcome the existing pretensioned force, a small deflection of the end sections 36 on the printed circuit board 40 produces a substantial contact force on the electrical paths 41 thereby contributing to a good electrical connection.

In addition, the particular arrangement of the contacts 38 also facilitates the electrical connection.

That is, as the printed circuit board 40 is inserted, the first contact bears on the surface of its associated circuit path 41 and rubs or burnishes the surface material to form a cleaned path for the second contact. As a result, a better metal-tometal contact is made and the resulting connection exhibits less contact resistance.

Finally, the manner in which the support block 20 and the terminal members 30 are designed allows ready adjustment of the force necessary to insert the printed circuit board 40. For example, where terminal members such as those illustrated in FIG. 2 are being used, the staggered depths of the grooves 29 will cause the terminal members 30 to be staggered with respect to each other when they are inserted in the support block 20. Since the terminal members are staggered, they will engage the printed circuit board 40 sequentially as it is inserted. Consequently, not all of the terminal members need be deflected at once, thus reducing the required insertion force.

The same result is also easily achieved with the version of the terminal members 30 shown in FIG. 1. For example, the locating tab 39 can be modified and relocated to fit the grooves 29. Similarly, the support plug 20 can be modified to include an appropriate boss or stop (not shown) adapted to engage the illustrated locating tab 29. In either case, the terminal members will be staggered, thereby avoiding the necessity for deflecting all at once when inserting the printed circuit board 40.

In summary, an electrical connector has been disclosed in which a support block and one or more terminal members cooperate to achieve a device of small size which is capable of simple, inexpensive fabrication and which performs its intended function in an efficient manner.

It is to be understood that the above-described arrangements are merely illustrative of the application of the principles of this invention. Numerous other arrangements may be devised by those skilled in the art without departing from the spirit and scope of the invention.