Electrical connector assembly with improved alignment/guide means

Abstract: A high density electrical connector assembly is disclosed and includes a male plug connector (10) having a protruding insulating housing portion (16) with a plurality of passageways (18) therethrough. A plurality of pin contacts (20) are mounted in the passageways. A female receptacle connector (12) has a recessed insulating housing portion (38) for receiving the protruding insulating housing portion of the male plug connector. A plurality of socket contacts (52) are mounted in the recessed insulating housing portion and project from a mating face (48) thereof for receiving the pin contacts. Complementary interengaging keys (62) and keyways (64) are provided between the housing portions of the connectors to properly align the connectors in initial mating engagement. A plurality of guide pins (70) project from one of the insulating housing portions, and a plurality of corresponding guide holes (74) are provided in the other of the insulating housing portions to finely position the pin and socket contacts to attain final mating alignment thereof.

Description: This invention generally relates to an electrical connector assembly of the preamble to claim 1. A connector assembly of that kind (US-A 3,614,711) has pins and sockets as well as keys and keyways which all interengage, yet the interengaging order is not disclosed. In a further known connector assembly (EP-A 0 443 492) a pair of elongate members is provided for aligning and keying the connectors together. First, the elongate members enter holes, then side walls of the housing interengage and then the pins of one connector enter the apertures of the other connector. The elongate members are rather thick and do not lend themself for high density applications. High density electrical connectors are used in a wide variety of applications, including indudtrial-type electrical connectors. High density connectors are desirable because they reduce connector sizes, thereby requiring less overall space and eliminating excess bulk. This is highly advantageous in many applications, such as aircraft and aerospace applications, where space and weight savings are at a premium. A typical type of electrical connector assembly of the character described is a circular connector assembly which includes a male plug connector and a female receptacle connector similar to the connector assembly of US-A 3,614,711. A coupling ring is rotatably mounted about one of the connectors for rotatably coupling the connectors in mating interengagement. The coupling system may utilize, for example, bayonet type or screw-thread type shells. Small high density pin and socket contacts interconnect when the plug and receptacle connectors are rotatably mated. As the density of electrical connectors used in such applications increases, problems arise upon mating of the connectors due to misalignment and resulting damage to the exposed pin and socket contacts. It generally is known in the art that cylindrical connectors may be keyed to properly position the connector housings prior to mating. The inventor has determined that the above type of guide means between the connector housings, alone, is not sufficiently precise to accurately align the increasingly dense array of pin and socket contacts where tight tolerances are required. Such high density connectors also cause problems due to the high insertion forces required to mate the high number of contacts, especially in environments where the connectors are not easily accessed or, for instance, in a blind mating condition or where the connectors must be cycled repeatedly. Therefore, there is a need for improved precise or fine alignment of such connectors during mating, without increasing the mating insertion forces. This invention is directed to satisfying such a need and solving the problems outlined above. An object, therefore, of the invention is to provide a new and improved alignment/guide means for high density electrical connectors of the character described. The invention is defined in claim 1. The exemplary embodiment of the invention is disclosed for use in a high density electrical connector assembly which includes a male plug connector having a protruding insulating housing portion, with a plurality of passages therethrough. A plurality of pin contacts are mounted in the passages. A female receptacle connector has a recessed insulating housing portion for receiving the protruding insulating housing portion of the male plug connector. A plurality of socket contacts are mounted in the recessed insulating housing and project from a mating face thereof for receiving the pin contacts. The invention contemplates the combination of complementary interengaging guide means between the housing portions of the connectors to properly align the connectors in initial mating engagement. Fine alignment means project between the housing portions of the connectors to finely position the pin and socket contacts to attain proper final mating alignment. The fine alignment means are configured for interengagement after interengagement of the guide means and before interengagement of the pin and socket contacts. In the preferred embodiment of the invention, the fine alignment means include at least one guide pin projecting from one of the insulating housing portions and a guide hole in the other of the insulating housing portions. As disclosed, the guide pin projects from the mating face of the recessed insulating housing portion of the female receptacle connector, and the guide hole is formed in the protruding insulating housing portion of the male plug connector. A feature of the invention is to provide a wear-resistent bushing which lines the guide hole, the bushing being of metal material to receive a metal guide pin. This reduces the wear about the guide hole in applications of repeated coupling and uncoupling of the connectors. The invention is readily applicable for circulartype connectors which include a coupling ring rotatably mounted on one of the connectors and rotatably engageable with the other connector for drawing the connectors into mating engagement. The complementary interengaging guide means between the housing portions of the connectors may be provided in the form of a key on one of the housing portions and a keyway in the other of the housing portions. Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. Brief Description of the Drawings The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings in which like reference numerals identify like elements in the figures and in which: Figure 1 is a perspective view of a connector assembly embodying the concepts of the invention consisting of a female receptacle connector and a male plug connector; FIGURE 2 is a fragmented side elevational view of a male plug connector embodying the concepts of the invention; FIGURE 3 is an end elevational view looking toward the left-hand end of Figure 2; FIGURE 4 is a fragmented side elevational view of a female receptacle connector embodying the concepts of the invention; FIGURE 5 is an end elevational view looking toward the right-hand end of Figure 4; FIGURE 6 is a view similar to that of Figure 4, further broken away to illustrate one of the guide pins; and FIGURE 7 is a view similar to that of Figure 2, further broken away to illustrate one of the guide holes. Detailed Description of the Preferred Embodiment Referring to the drawings in greater detail, Figure 1 shows a male plug connector, generally designated 10, and a female receptacle connector, generally designated 12. The connectors are mateable in a high density electrical connector assembly in which the invention is applicable. Figures 2 and 3 show the male plug connector 10 which includes a dielectric housing, generally designated 14, having a protruding housing portion 16. The housing is unitarily molded of insulating plastic material or the like. The protruding housing portion 16 defines a plug of the connector and includes a plurality of through passageways 18 for receiving and mounting respective plug or pin contacts 20 therein. The passageways have open mating ends 22 in a mating face 24 of the protruding housing portion. The plug or pin contacts are terminated to a plurality of insulated electrical wires 26 (Figs. 1 and 2). It can be seen in Figure 1 that plug connector 10 is a very high density electrical connector. As shown, the connector mounts in excess of 62 contacts 20 per cm 2 (400 pin contacts 20 per square inch) in a close hexagonal array. Plug connector 10, and receptacle connector 12 are circular connectors designed for mating interengagement and are mechanically and electrically coupled by a coupling ring 28 (Fig. 1) rotatably mounted on housing 14 by means of a radially outwardly projecting peripherally flanged portion 30 of the housing engaged by a locking ring 32 inside coupling ring 28. Therefore, the coupling ring is rotatable about the housing. The coupling ring has internal threads 34. Up to this point, the above description of male plug connector 10 is generally conventional for an industrial, circular, high density plug connector. Figures 4 and 5 show the female receptacle connector 12 which includes a housing shell, generally designated 36, unitarily formed of conductive metallic material or the like. The shell has a recessed portion 38 defining a cylindrical recess 40 for receiving protruding insulating housing portion or plug 16 of plug connector 10. The outside of shell 36 is externally threaded, as at 42, for threading engagement with internal threads 34 of coupling ring 28 of plug connector 10, whereby the plug and receptacle connectors are mated by inserting plug portion 16 of the plug connector into recess 40 of the receptacle connector and rotating coupling ring 28 to draw the connectors into mating condition. A dielectric insulating insert 44, unitarily molded of plastic material or the like, is disposed within shell 36 of receptacle connector 12 and is held therewithin by a lock ring 46 and interengaging shoulder means 47 between the insert and the shell. The insert defines a mating face 48 within recess 40 and is provided with a plurality of through passages 50 for receiving and mounting a plurality of receptacle or socket contacts 52 having receptacle or socket portions 54 projecting into the recess 40 from the mating face 48. The socket contacts are terminated to a plurality of insulated electrical wires 56. Like plug connector 10, and referring to Figure 5, receptacle connector 12 mounts a high number of socket contacts 52, with socket portions 54 thereof being visible in Figure 5. Again, there may be in excess of 62 contacts 54 per cm 2 (400 socket contacts per square inch) in a hexagonal array for mating with pin contacts 20 of plug connector 10. Again, up to this point, the above description of receptacle connector 10 is generally conventional for a high density, circular industrial connector. In fact, it can be seen that shell 36 of receptacle connector 12 has an enlarged, radially projecting peripheral flange 58 and a nut 60 threaded onto the outside of the housing for panelmounting the receptacle connector in a hole in an appropriate panel, with the panel sandwiched between flange 58 and nut 60. Generally, the invention is directed to the combination of complementary interengaging guide means between housing portions 16 of plug connector 10 and shell portion 38 of receptacle connector 12 to properly align the connectors in initial mating engagement, along with fine alignment means projecting between the housing portions to finely position pin and socket contacts 20 and 52, respectively, to attain final mating alignment. The fine alignment means are configured for interengagement after interengagement of the guide means and before interengagement of the pin and socket contacts. More particularly, the complementary interengaging guide means between housing portions 16 and shell portion 38 are provided in the form of a plurality of keys 62 integral with and projecting radially outwardly of plug portion 16 of housing 28 of plug connector 10. A plurality of keyways 64 are formed on the inside of recessed portion 38 of shell 36 of receptacle connector 12. It can be seen in Figures 3 and 5 that keys 62 and keyways 64 are irregularly spaced angularly about the array of pin and socket contacts, but the keys and keyways are matched in spacing to insure proper engagement of the pin contacts with predetermined ones of the socket contacts. Upon coupling plug and receptacle connectors 10 and 12, respectively, by means of coupling ring 28 as described above, keys 62 will enter keyways 64 to properly align the connectors in initial mating engagement. The fine alignment means, referring to Figures 6 and 7, are provided in the form of a plurality of guide pins 70 fixed within holes 72 in insert 44 (i.e. the housing means) of receptacle connector 12. The guide pins project into recess 40 from mating face 48. A plurality of guide holes 74 are formed in plug housing portion 16 of plug connector 10 for receiving guide pins 70 of the receptacle connector. Although only one guide pin 70 and one guide hole 74 are shown in Figures 5 and 6, respectively, preferably a plurality of such interengaging guide pins and guide holes are provided. For instance, referring back to Figures 3 and 5, it can be seen that four guide pins 70 are intermingled among socket portions 54 of socket contacts 52. As shown in Figure 5, the guide pins are located near the periphery of the hexagonal array of the socket contacts. Correspondingly, there are four guide holes 74 at correspondingly located positions in relation to pin contacts 20 of plug connector 10 in Figure 3. Referring back to Figure 6, it can be seen that guide pins 70 are longer than socket portions 54 of socket contacts 52, but the guide pins stop short of the ends of keyways 64. Consequently, the fine alignment means provided by the guide pins (and guide holes 74) interengage after interengagement of the guide means provided by keys 62 and keyways 64, but before interengagement of pin contacts 20 and socket contacts 52 (54). At least, the guide pins should interengage within the guide holes before the pin and socket contacts engage to ensure proper and fine positioning of the pin and socket contacts to attain mating alignment thereof, which otherwise could not be accomplished by the more "coarse" alignment provided by keys 62 and keyways 64. Lastly, a feature of the invention is shown in Figure 7, wherein guide holes 74 are lined by wear-resistent bushings 76. In some applications where the connectors are subjected to repeated mating and unmating, particularly with housing 14 of plug connector 10 being fabricated of dielectric material such as plastic or the like, there would be a tendency for guide pins 70 to wear and enlarge the guide holes, particularly if the guide pins are fabricated of metal material. Obviously, wearing and consequent enlargement of the guide holes will detract from the fine alignment of the pin and socket contacts. By lining the guide holes with wear-resistent bushings, such as metal or the like, this wear is obviated, which is quite useful in applications of repeated mating and unmating of the connectors.

Claims: An electrical connector assembly for connecting a first set of insulated wires (26) to a second set of insulated wires (56), said connector assembly including: a cylindrical plug connector (10) having a mating face (24) and including a protruding insulating plug housing (16) with a plurality of passageways (18) formed therein, a plurality of plug contacts (20) mounted in the passageways (18) extending generally parallel to the plug connector axis toward the plug mating face (24), a key (62) proximate the plug mating face (24) from the protruding insulating plug housing (16), and a coupling ring (28) rotatably mounted on the protruding insulating plug housing (16); and a cylindrical receptacle connector (12) having a mating face (48) and including a housing (36) having a shell (38) with a recess (40) for receiving the protruding insulating plug housing (16) and for mechanically and electrically engaging the coupling ring (28), a keyway (64) formed on an inside surface of the recessed shell (38) adapted to interengage the integrally formed key (62) of the protruding insulating plug housing (16), an insulating receptacle insert (44) disposed within the shell (38), and a plurality of receptacle contacts (52) mounted in the insulating receptacle insert (44) extending generally parallel to the receptacle connector axis, each having portion (54) which projects into the recess (40) from the receptacle mating face (48) and being adapted to interengage the plug contacts (20), whereby the key (62) and keyway (64) insure proper initial alignment of the plug connector (10) with respect to the receptacle connector (12) ; characterized in that at least a guide pin (70) is mounted in the insulating receptacle insert (44) of the receptacle connector (12), extends generally parallel to the receptacle contacts (52) and projects into the recess (40) from the receptacle mating face (48) by a distance which is greater than the length of the receptacle contact portions (54) past the mating face (48); at least a guide hole (74) is formed in the protruding plug housing portion (16) of the plug connector (10) adapted to receive the guide pin (70); the plug contacts (20) are recessed from the plug mating face (24), and in that the guide pin (70) and guide hole (74) are configured for interengagement after interengagement of said key (62) and keyway (64) and before interengagement of the plug and the receptacle contact portions (20, 54). The electrical connector assembly as set forth in claim 1, wherein the plug connector (10) mounts in excess 62 plug contacts (20) per cm 2 (400 contacts per square inch). The electrical connector assembly as set forth in claim 1 or 2, wherein the plug contacts (20) are mounted in the protruding plug housing (16) in a close hexagonal array. The electrical connector assembly as set forth in claim 3, wherein the guide hole (74) is located proximate the periphery of the hexagonal array of the plug contacts (20). The electrical connector assembly as set forth in any of claims 1 to 4, wherein the guide hole (74) is lined with a wear-resistant bushing (76).

Inventors: VAN WYK FRED, VAN WYK, FRED
Applicants: MOLEX INC, MOLEX INCORPORATED
Application year: 1993
Main classification: H01R13
IPC codes: H01R13