Electrical connectors

Dec. 26, 1961

3,015,083

M. A. JURIS

ELECTRICAL CONNECTORS Filed Jan. 25, 1960

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United States Patent Office

3,015,083

Patented Dec. 26, 1361 vidual contact cavities of novel form each arranged to house one of the contacts. The contacts themselves are also of novel configuration and structure, as well as being of mechanical design particularly suited to mass production, and . so constructed that they may achieve minimum variation of operating characteristics without resorting to impractical manufacturing tolerances.

. As illustrated, the connector may be of the form shown in the attached drawing, wherein:

. FIGURE 1 is a plan view of the front face of a typical circuit board connector constructed in accordance with the present teachings, showing the formation of the central channel in which the circuit board may be inserted between opposite rows of opposed contact cavities. The view is shown with most of the metallic contacts removed irom the cavities for clarity.

. FIGURE 2 is a detail sectional view taken substantially on the plane of the line 2—2 of FIGURE 1 and showing the contacts;

FIGURE 3 is a detail sectional view similar to FIGURE 2 but showing the manner in which the blades of the metal contacts are flexed by the insertion of the terminal edge of a circuit board;

. FIGURE 4 is a detail sectional view taken substantially, on the plane of the line 4—4 of FIGURE 2 and showing the relationship between the metal contacts and the cavities in which they are housed;

. FiGURE 5 is a detail sectional view taken substantially on the plane of the line 5—5 of FIGURE 2; and

FIGURE 6 is a perspective view of a preferred embodiment of metallic contact employed in the connector.

The connector illustrated includes a molded dielectric body portion or receptacle 10 formed of relatively hard - ----------------rectangular shape. The mounting ears 11 provided at each end of the piece are pierced at 12 to provide for attachment to other equipment. The length of the receptacle may vary in accordance with individual requirements, parAs illustrated, the receptacle has a long, narrow, deep longitudinal channel 13 extending inwardly from the front face 54 of the connector to a bottom wall 15 contiguous with the back surface 16. This narrow channel — is thus adapted to receive a leading terminal edge of a printed circuit board 17 (FIGURE 3) which may include conventional conductive strips 18 on one or both of its opposed face surfaces. The channel 13 is preferably beveled around its forward edges as illustrated at ⁰⁰ 19, to facilitate insertion of the circuit board. Also, if desired, one or both of the ends of the channel may have an offset recess 21 to provide clearance for polarizing keys (not shown) which may be mounted on the edges of the circuit board.

One or both of the inside face walls 22, 23, of the receptacle channel 13 are provided with a series of contact cavities 24 which, in the preferred construction of the invention, may be of identical formation and regularly spaced on opposite sides of the channel 13. Each of these cavities consists of a generally rectangular cored opening extending entirely through the dielectric body from the front face 14 through the bottom wall 15 and to the rear face 16 of the receptacle. These cavities are 65 spaced slightly beyond the sides of the channel walls 22 and 23, but are connected to the channel by means of narrow central slots 25, so that a pair of relatively thin, oppositely disposed retaining flanges 26 are provided along the inside edges of each of the barrier walls 27 of the cavities is also provided with a relatively small rectangular groove 28 extending down the outer wall of

3,015,083 , .. . ELECTRICAL CONNECTORS Mitchell A. Juris, Chicago, Ill., assignor to Ampheuolitos·;· Electronics Corporation, Broadview, III., a corporation of Delaware ’

Filed Jan. 25, I960, Ser. No. 4,307

Claims. (Cl. 339—176)

- Ί his invention relates to electrical connectors, and F particularly to a unique conformation of a dielectric con| nector body and to an improved arrangement of the parts of tue metallic contacts carried therein.

It is among the primary objects of the invention to provide sheet metal contacts of improved and novel formation, together with a molded dielectric receptacle having contact cavities so related to the contacts that they may be easily, quickly and conveniently mounted or removed, either before or after the conductor wires associated with the individual contacts are attached thereto More specifically, it is an object of the invention to provide sheet metal contacts so designed that they may be soldered or crimped to the terminal ends of flexible wire conductors prior to assembly and assembled with the connector housing by manually snapping the contacts into place without the necessity for any type of tool to accomplish the installation. It is a related object, however, to provide a contact and housing therefor of such mechanical design that the individual contacts, while adapted to hold themselves firmly in their respective cavities under normal circumstances, may nonetheless be easily 30 removed without unsoldering the terminals and without disturbing adjacent contacts in the same connector.

An extremely important object of the invention is the provision of contacts adapted for use in multinlp rnnrw» tors of the smaller types, and in the schalted “orinted - ι°7 Γ™” °· .^re?^eptac₁‘^{e 10 formed of} gelati circuit”, connectors, wherein a thin sheet or “board” of f--^m±^{na! throu}g^h°ut and of elongated dielectric material provided with conductive strips on its face surfaces is employed as the plug of the connector. According to the present invention, both the connector receptacle and the metallic contacts therefor are of such 4(1 'Τ'ΊΓ'' requeue design as to be capable of establishing and maintaining » -- t,^he.^numbsr °f contacts required, a dependable high conductivity electrical union between each contact and. its corresponding circuit board terminal, and of such design as to lend themselves to production _r&lt;nKmethods whereby an unusually high degree of uniformity 45 j? may be maintained as to insertion and withdrawal forces before and after an extended period of use, as well as between the several contacts which may be included in a single connector.

A further object is to provide an electrical contact having the characteristics indicated above and of such mechanical design as to be capable of repeatedly engaging and releasing the coacting terminal portion of a circuit board smoothly and dependably without perceptible tendency toward scratching, galling or otherwise damag- 55 ing the rather delicate surfaces of the circuit board.

A further object of the invention is the provision of an improved circuit board connector having the desirable qualities indicated above, wherein provision is not only made for polarizing the connector to prevent improper 60 insertion of the circuit board in the receptacle, but wherein each of the individual contacts are also polarized with respect to their separate cavities so that they cannot be inadvertently reversed or otherwise improperly inserted therein.

The. above objects are accomplished in the present invention by the combination of a plurality of metal contacts and a molded dielectric receptacle of the forms hereinafter disclosed. The dielectric body, which in its may consist of a single one-piece molded part formed of dielectric material throughout, with a plurality of indipreferred form is designed as a circuit board connector, 70 formed between the contact cavities (FIGURE 4) Fac-h

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3,015,083 the cavity 24 and terminating in a retaining shoulder 29 (FIGURE 2).

The metallic contacts of the connector are preferably sheet metal stampings with each of the individual contacts formed from a single integral sheet die cut and folded upon itself to provide a relatively rigid mounting shank supporting a comparatively yieldable spring contact blade. The formation of the parts of the contacts is such that they are adapted to be retained in the contact cavities heretofore described by a snap action latch so designed that the contacts may be inserted without tools, yet may be easily removed if required. The arrangement of parts illustrated also provides the connector with integral yieldable contact blades having sufficient resiliency to maintain adequate surface-to-surface pressure on the mating circuit board, but with means for limiting the flexing movement of the contact blades.

To accomplish the above objectives, the individual metal contacts are formed with a relatively rigid elongated shank member 31 consisting of a fairly wide, flat outside web 32 having a pair of relatively narrow reinforcing flanges 33 disposed along its opposite longitudinal edges and with a pair of abutment shoulders 34 extending from the flanges 33 at an intermediate point along their length. Thus, when the contact shank 31 is inserted into one of the cavities 24 of the dielectric receptacle, a terminal portion 35 of the shank will extend therefrom to permit easy access to the individual contacts. The contact shanks are thus formed in a shape to be received in close fitting relationship within the cavities 24 (FIGURE 4) and provision is made for releasably retaining the contacts in the cavities by the provision of a latching tab 36 bent outwardly from a portion of the web 32 of the contact shank. In practice, th^:s tab will be flexed into the plane of the web by cam action of the back wall of the cavity as the contact is inserted in the cavity from the back of the receptacle, but the tab will then spring outwardly to the position of FIGURES 2 and 3, and will thereafter prevent accidental displacement of the individual contacts from the assembly.

The contacts each include a yieldable blade portion generally designated as 42, comprising an integral extension of the outer web 32 of the contact shank, but of narrower dimensions as best shown in FIGURE 6. This blade extends from the contact shank to a relatively sharp return bend 43 and thence to a yieldable bow portion 44. The bow portion 44 of the contact blade has a smoothly rounded face surface 45 and includes an extension brace 46 interconnecting it wilh a supporting rocker 47. As seen in FIGURES 2 and 3, the rocker 47 is normally disposed between the side flanges 32 of the contact shank and in slightly spaced relation with the outer web 32 thereof, but moves back to engage the web 31 and support the contact blade when the circuit board is plugged into the receptacle. A limit tab 48 extends from the rocker 47 to engage the abutment wall 49 on the bottom portion 15 of the receptacle body, to limit forward flexing of the contact blade.

From the above it will be apparent that the teachings of the present invention provide a connector structure having important advantages over the prior art in several respects. For one thing, the contacts and the receptacle in which they are mounted are formed to provide maximum rigidity in the mounting and terminal portions of the contact, together wtih an arrangement whereby the relatively thin contact blades are braced at the proper point to provide adequate contact pressure. At the same time the flexing cf the individual blades is limited in a manner to effectively control the insertion and withdrawal forces. This renders the performance characteristics of the contacts quite uniform, and aids in protecting the parts from accidental damage.

In addition to achieving these results, it is to be noted that the individual contacts may be soldered or crimped to their respective conductors prior to assembly, so that they may be put in place merely by slipping each contact into its designated cavity from the back face 16 of the receptacle. The contacts are held against accidental displacement by the retaining latches 36 provided, but may be in5 dividually removed for inspection or replacement merely by slipping a small tool, such as a wire or straight pin, down the groove 28 to release the latching tine 36 from the retaining shoulder 29. The arrangement of the contacts in the dielectric body is such that they may be closely 10 grouped, yet with comparatively long mstsi-to-metal creepage paths afforded by the flanges 26 on the inside ends of the barrier walls 27. In addition, it is to be noted mat both the metallic parts and the molded receptacle of the connector are well suited to economical mass production 15 methods of manufacture whereby satisfactory tolerances may be maintained without prohibitive manufacturing costs.