Locking Mechanism for Rectangular Electrical Connector

The present invention relates generally to an electrical connector and, more particularly, to a locking mechanism for a rectangular electrical connector.

There are basically two types of electrical connectors, namely, circular and rectangular. The plug and receptacle members of the circular connector are normally interlocked by either a threaded coupling nut or a bayonet coupling nut. Rectangular connectors utilize mounting surfaces or screws through flanges on the plug and receptacle shells to hold the connectors in their mated condition.

Some connectors embody self-locking mechanisms contained in or attached to the connector shells to provide an interlock between the connector halves and to maintain the connector in the mated condition. The self-locking mechanisms previously embodied in rectangular connectors have been complicated and bulky in nature which results in an increase in cost, an increase in weight, and a reduction in reliability of the connectors. Additionally, the bulkiness of these mechanisms places a limitation on the utilization of the connectors in those applications where connector size is important.

U.S. Pat. No. 3,843,853 to Panek et al. discloses a self-locking mechanism for a circular connector which has been referred to as a "ring lock." In this connector, matching grooves are formed in the outer surface of the plug shell and the inner surface of the receptacle shell. The grooves are aligned when the shells are fully mated. The groove in the plug shell is deeper than the groove in the receptacle shell. A split ring is mounted in the grooves. In its normal unstressed condition the ring is lodged in both the grooves thereby interlocking the shells of the mating plug and receptacle halves of the connector. The locking ring is retained in its locking position by a radially extending pin disposed between the free ends of the split ring. When the pin is removed the split ring is free to be contacted upon application of an axially directed unmating force to the mating connector members. A similar ring lock arrangement for a pipe joint is disclosed in U.S. Pat. No. 3,521,911.

Heretofore, no one has applied the ring lock principle to a rectangular connector. That is the object of the present invention. By doing so, a self-locking rectangular connector may be provided which is neither complicated nor bulky as the other self-locking rectangular connectors mentioned hereinbefore. The decrease in comparative complexity decreases the cost and increases the reliability of the connector. The decrease in bulkiness allows the connector to be utilized in applications where space is an important factor.

According to a principal aspect of the present invention, there is provided an electrical connector having mating plug and receptacle members each embodying rectangular shells one telescopically mounted within the other. The shells have elongated sides and opposed relatively shorter ends. Matching grooves are formed in the inner and outer surfaces of the elongated sides of the shells, running lengthwise of such sides. An elongated wire is positioned in each of the grooves in the plug shell. Actuating means is provided for shifting each of the wires outwardly to become partially lodged into the receptacle shell grooves to thereby lock the plug and receptacle members together. By releasing the actuating means, the plug and receptacle members may be disengaged in a manner similar to the ring lock circular connector described hereinbefore.

Thus, the present invention provides a quick releasable, but positive locking mechanism for a rectangular connector which provides the locking action along the long sides of the connector which is particularly advantageous due to the fact that the loading on the connector shells are due to the electrical components being distributed along the length of the shells.

FIG. 1 is a partial longitudinal sectional view through the connector of the present invention with the actuating devices for the locking mechanism shown in their forward locking position;

FIG. 2 is a perspective view of the plug connector member of the connector illustrated in FIG. 1 showing one of the locking wires removed from the plug shell;

FIG. 3 is a transverse sectional view taken along line 3--3 of FIG. 1 showing the locking wires in their release, unlocking position;

FIG. 4 is a sectional view similar to FIG. 3 showing the locking wires in their outer locking position;

FIG. 5 is a sectional view taken along line 5--5 of FIG. 3; and

FIG. 6 is a sectional view taken along line 6--6 of FIG. 4.

Referring now to the drawings in detail, the connector of the present invention, generally designated 10, comprises a plug connector member 12 and a receptacle connector member 14. The plug connector member 12 has a shell 16 of rectangular configuration which is telescopically mounted within the receptacle shell 18 of complementary rectangular configuration. The plug shell 16 contains an insulator assembly 20 in which there are mounted a plurality of electrical contacts 22. The receptacle shell 18 also contains an insulator assembly 24 containing contacts 26 which mate with the contacts 22 when the plug and receptacle members are interengaged. The construction of the connector insulators and contacts may be conventional, and constitutes no part of the present invention. If desired, endbells 28 and 30 may be mounted on the rear of the plug and receptacle shells, respectively.

The locking mechanism for the plug and receptacle members includes a pair of elongated locking wires, each designated 32. The locking wires are located in elongated grooves 34 formed in the outer surface of the relatively long sides 36 of the plug shell 16. The grooves 34 intersect grooves 38 formed in the relatively short ends 40 of the plug shell. Each locking wire has a leg 42 formed at its opposite ends and extending generally perpendicular of the length of the wire. The legs 42 lie in the grooves 38. Inwardly extending tabs 44 are formed on the legs 42. The wires are retained on the plug shell by the tabs 44 fitting into notches 46 at the ends 40 of the plug shell.

As best seen in FIG. 5, the depth of each groove 34 is sufficient to allow the locking wire 32 to be disposed entirely within the groove, i.e., beneath the outer surface of the elongated side 36 of the plug shell 16. When the locking wires are so disposed, they are in their release, unlocking position.

As seen in FIGS. 3 to 6, elongated grooves 50 are formed in the inner surface of the receptacle shell 18 matching the grooves 34 in the plug shell. The grooves 50 are shallower than the grooves 34 so that when the locking wires 32 are urged outwardly they will become only partially lodged into the grooves 50, as seen in FIGS. 4 and 6, thereby providing a positive interlock between the connector shells 16 and 18. Thus, in principal the wire lock arrangement of the present invention functions similarly to the ring lock disclosed in the aforementioned Panek et al. patent. However, in contrast to the ring lock mechanism in which the split ring is normally disposed in an expanded locking position, in the present invention it is necessary to provide an actuating device for spreading the locking wires 32 outwardly into the grooves 50 in the receptacle shell. Such actuating device, generally designated 52, is provided at each end 40 of the plug shell. Each actuating device comprises a plunger 54 axially slidable in a housing 56 on the end 40 of the plug shell. The plunger has a stepped configuration providing a forward narrow portion 58, a rear wider portion 60 and a tapered transition region 62 providing a pair of inclined cam surfaces 64 on its opposite sides.

In FIGS. 2 and 3, the plunger 54 is shown in a retracted, release position wherein the forward narrow portion 58 of the plunger is disposed between the legs 42 on the ends of the locking wires, thus allowing the wires to be entirely disposed within the grooves 34 in the plug shell. In this position of the locking wires, the plug and receptacle connector members are free to be slidably interengaged (the plug shell 16 will slide into the receptacle shell.) The plungers 54 may be shifted to the retracted position against the force of coil springs 66 by outwardly extending fingers 68 on the plungers. When the connector shells are interengaged, the operator will release the fingers 68 whereupon the springs 66 will urge the plungers forwardly so that the cam surfaces 64 thereon will cooperate with the ends of the legs 42 urging the locking wire outwardly into the grooves 50 in the receptacle shell, as illustrated in FIGS. 4 and 6, thereby positively locking the connector members together. The locking wires are retained in such locking position by the wider portions 60 of the plungers 54 being disposed between the ends of the legs of the wires as seen in FIG. 4.

It is particularly advantageous that the locking wires 32 extend along the long sides of the plug and receptacle shells because the loading on the shells due to the electrical contacts therein is distributed along this length. This provides a considerable improvement over those locking mechanisms utilized in prior rectangular connectors which are typically disposed at the ends of the connector shells.

To unmate the connector, the plungers 54 are retracted by pressing rearwardly on the fingers 68 so that only the narrow forward portions 58 of the plungers are disposed between the legs 42 on the locking wires, thus allowing the locking wires to collapse into the grooves 32 in the plug shell. The wires collapse into such grooves upon application of an axially directed force withdrawing the plug shell from the receptacle shell whereupon the curved surface of each groove 50 in the receptacle shell functions as a camming surface acting upon the curved surface of the corresponding locking wire urging it inwardly into the groove 34. If desired, the plungers 54 of the actuating devices of the connector may be operated either semi-automatically, or fully automatically, which may be desirable if the connector must be unmated from a remote position.

From the foregoing, it will be appreciated that the wire locking mechanism of the present invention not only provides a very effective locking arrangement along the entire length of a rectangular connector, but also is relatively simple, inexpensive, and does not add significantly to the size of the connector.