High-density cable connector

Abstract: A connector assembly including contact terminals (50) which may be arranged in a side-by-side array of extremely close pitch spacing without increased congestion of the insulation displacing plates (54). The connector assembly also includes a sturdy and easily assembled housing (30, 40, 60, and 70) for the contact terminal array as described above. The housing includes a terminal support block (40) with cavities (44) and channels (42) for seating the respective contact terminals (50), the cavities (44), and channels (42) conforming to the contact terminals (50) such that the contact terminals (50) are supported against any wire insertion forces to thereby prevent crumpling.

Description: The present invention relates to electrical connectors according to the preamble of claim 1, and, in particular, to a discrete connector assembly including a high-density array of terminal contacts for terminating multiple insulated wire conductors. Electrical connector technology is rapidly evolving toward higher-density arrangements of contact terminals and smaller components for housing the terminals and completing the necessary mechanical interfaces. To keep pace, the contact terminals themselves must be reduced in size to permit a tighter side-by-side array (a.k.a. "pitch"). However, it is a perplexing problem to reduce the pitch without sacrificing the strength, durability, and/or ease of assembly of the connector. Moreover, if the contact terminals are spaced too closely, stray capacitive couplings may result in excxessive noise and cross-talk. One example of a connector assembly with a high-density array of solder tails is shown in U.S. Patent No. 5,064,391. As shown in Fig. 4 therein, the contacts 22 are formed and arranged asymmetrically to facilitate a tighter grouping of solder tails 90. As shown in Fig. 3 therein, the contacts 22 have barbs 114 to anchor them within their respective contact channels. U.S. Patent No. 4,802,860 shows in Fig. 3 therein a contact 20 of the type having a widened section 22 and an arrangement of such contacts wherin the wider intermediate portions 22 of adjacent contacts are vertically spaced to allow a slight overlap. Another example of a high-density cable terminating connector is shown in U.S. Patent No. 4,781,615, which discloses an electrical connector for having the features of the pre-characterizing part of claim 1. As shown therein in Fig. 2, a plurality of contacts 20 are aligned side-by-side within a discrete connector assembly (including components 68, 28, 16, and 70). The contacts 20 are provided with a slotted insulation displacing plate 42 which penetrates the insulation of a wire compressed in the slot to make conductive contact. It is taught how contacts 20 can be formed in various lengths to offset adjacent insulation displacing plates 42 when the contacts 20 are arranged side-by-side. This way, the pitch between contacts 20 can be reduced without likewise reducing the spacing betwen adjacent insulation displacing plates 42. The remaining components (68, 28, 16, and 70) of the discrete connector assembly may be assembled in a sequence which includes insertion of wires 56 into the insulation displacing plates 42. The wire insertion step may be accomplished in mass using the method and device shown and described in U.S. Patent No. 5,079,827. US-A-5,062,805 discloses an electrical connector having a terminal support block including rows of cavities and channels, wherein the cavities are offset with respect to each other such that parts of the wire terminating portions in one row overlap parts in a second row of cavities. The channels extend towards different edges of the support block. It would be greatly advantageous to improve upon the '615 patent connector assembly to further reduce the pitch between adjacent contacts. However, this is problematic because a closer pitch spacing would likewise bring the insulation displacing plates into close proximity, and this may lead to noise, cross-talk, increased frequency of shorting between adjacent contact terminals, and an increased frequency of dielectric (low voltage) breakdown. Moreover, any reduction in the dimensions of the contacts would sacrifice their strength, and this would increase the tendency of the insulation displacing plates 42 to crumble, especially with the insertion forces generated during automatic wire insertion as shown in the '827 patent. It is, therefore, the object of the present invention to provide an improved contact terminal which facilitates a side-by-side array having a closer pitch spacing without increased congestion of the insulation displacing plates. The invention provides an electrical connector as defined in claim 1. Preferred embodiments are defined in the dependent claims. The invention provides a sturdy and easily assembled discrete connector assembly for housing a contact terminal array as described above. Moreover, the above-described contact terminals are confonned to the connector assembly so that the contact terminals are supported against the wire insertion forces to prevent crumpling. The present invention provides a high-density connector assembly which prevents shorting of close pitch contact terminals and eliminates dielectric (low voltage) breakdown. In accordance with the above-described and other objects, the present invention provides a high-density array of contact terminals for a connector assembly. Each contact terminal in the array has a wire terminating portion and an elongate terminal pin extending integrally from the wire terminatiin portion. The terminal pin is narrower than the wire terminating portion and is joined thereto along a base edge to form a tee intersection. The terminal pin extends a short distance from the wire terminating portion to an elbow and is angled outward from the elbow. In addition, the terminal pins of the contact terminals are formed in at least two different lengths such that the wire terminating portions are offset when the contact terminals are arrayed side-by-side with their points in alignment. The offset wire terminating portions and elbowed terminal pins serve to facilitate a smaller pitch between adjacent terminal pins without crowding adjacent wire terminating portions. The invention also incorporates the above-described contact terminal array in a connector assembly, the connector assembly additionally including a terminal support block for carrying the contact terminals. The terminal support block is formed with a plurality of cavities each adapted to receive the wire terminating portion of one of said contact terminals and a plurality of parallel channels each intersecting a corresponding cavity and extending outward therefrom for seating and aligning the respective contact terminal. The channels are deeper than the corresponding cavities to provide lateral support ledges conforming to the corners of the wire terminating portions of the contact terminals. The connector assembly also includes a plug housing. The plug housing is formed with a central aperture for embracing the terminal support block and is insertable onto the terminal support block to hold the contact terminals captive within their channels. As an additional feature, the connector assembly may include a shroud for electrically shielding the contact terminals. The shroud has an open end insertable on the terminal support block and, when inserted, substantially encircles the contact terminals to provide an electrical shield. The invention will now be described by way of example with reference to the accompanying drawings in which: FIG. 1 is a perspective view of a shielded plug-type connector assembly 10 according to the present invention for terminating a shielded multiple-wire cable. FIG. 2 is an exploded perspective view showing the manner of seating the contact terminals within the terminal support block of FIG. 1. FIG. 3 is a sequential perspective view of FIG. 2 showing the contact terminals seated within the terminal support block. FIG. 4 is a top view of break-away contact terminals of the type used in FIGS. 1-3. FIG. 5 is an exploded cross-sectional view from the rear of the terminal support block illustrating the manner of seating two contact terminals therein. FIG. 6 is an exploded perspective view of the terminal support block seating a plurality of contact terminals and prepared to accept a plug housing. FIG. 7 is a sequential perspective view of FIG. 6 showing the plug housing inserted on the terminal support block over the contact terminals. FIG. 8 is an isolated perspective view of a cover panel as shown in FIG. 1. FIG. 9 is a partially-exploded cross-sectional view of the connector assembly of FIG. 1 showing the manner of anchoring a cover panel as in FIG. 8 onto the terminal support block. FIG. 10 is cross-section of a fully assembled double-sided connector assembly as shown in FIG. 1 when viewed from the rear. With more particular reference to the drawings, FIG. 1 is a perspective view of an electrical connector assembly 10 which is a shielded plug-type connector for terminating a shielded multiple-wire cable. It should be noted that the invention may be practiced in many other connector types, such as unshielded connectors and receptacle connectors. The shielded plug-type connector of FIG. 1 generally comprises discrete interlocking component parts including a cable terminating section 20 for terminating a conventional shielded multiple-wire cable and a plug connector section 24 projecting forwardly therefrom for mating with a conventional shielded receptacle-type connector. The plug connector section 24 includes a forwardly protruding terminal support block 40 with a plurality of contact terminals 50 seated therein. The plug connector section 24 also includes an open-ended shroud 30 mounted on and enclosing the terminal support block 40 for the protection of contact terminals 50. Shroud 30 may be formed or coated with a conductive material to provide a protective electrical shield around terminals 50. A conventional multiple-wire cable enters the cable terminating section 20 and is terminated therein. The contact terminals 50 bridge the connector assembly 10 to provide multiple electrical paths between the multiple-wire cable and the mating receptacle-type connector. Contact terminals 50 are anchored within the cable terminating section 20 and extend therefrom along terminal support block 40. To increase the density of connections, the terminal support block 40 may be formed to seat contact terminals 50 on both sides. In use, each insulated wire of the cable will maintain electrical contact with a corresponding one of the contact terminals 50 within the cable terminating section 20. Connector assembly 10 may then be inserted into a female receptacle assembly via the plug connector section 24, and multiple electrical connections will be completed via contact terminals 50. FIGS. 2 and 3 are sequential perspective illustrations showing the manner of seating contact terminals 50 within terminal support block 40. As shown in FIG. 2, contact terminals 50 are each formed with an elongate terminal pin or blade 52 extending forwardly from a substantially orthogonal wire terminating portion 54. The wire terminating portion 54 is provided with a slotted insulation displacing notch as is known in the art. The contact terminals 50 are provided with at least two different lengths of terminal pins 52. This way, when the contact terminals 50 are aligned side-by-side with the tips of terminal pins 52 in alignment, the wire terminating portions 54 are positioned along tiers, for example, two tiers as shown. The underside of terminal support block 40 is identically formed to seat additional contact terminals 50 in a like manner. Each side of the terminal support block 40 is provided with a plurality of terminal channels 42, each channel being sized to seat a corresponding one of contact terminals 50. Each of the channels 42 terminates inwardly of terminal support block 40 at a cavity 44 which conforms to the wire terminating portion 54 of the contact terminals 50. FIG. 3 shows the contact terminals 50 seated in their respective terminal channels 42 of terminal support block 40 with wire terminating portions 54 contained in cavities 44. The wire terminating portions 54 of the contact terminals are substantially restrained from lateral movement within cavities 44, however, slight leeway is maintained to yield a degree of freedom at terminal pins 52. A plurality of wire support collars 47 may be integrally molded in terminal support block 40, each behind a corresponding cavity 44. The wire support collars 47 illustrated in FIGs. 2 and 3 are designed to receive the insulated portion of the wires extending from the multi-wire cable, and each collar 47 includes an interior rib for insuring a secure resistance fit. The individual wires of the multi-wire cable are each seated in a corresponding support collar 47 and extend forwardly therefrom for termination in a corresponding wire terminating portion 54 of contact terminals 50. The need for an interior rib in each wire support collar 47 may be eliminated by increasing the interior arc of the collar beyond 180°. The additional embracement serves to provide an equivalent resistance fit. The particular details of the terminal channels 42 and cavities 44 in the terminal support block 40, and the manner in which contact terminals 50 are seated therein are important features of the invention. As shown in FIGS. 4 and 5, the wire terminating portions 54 are formed substantially orthogonally with respect to the terminal pins 52 of contact terminals 50. In addition, the wire terminating portions 54 are broader than the terminal pins 52 and define a pair of ears flanking the wire-gripping notch. The terminal pins 52 are joined to a base edge 58 of the wire terminating portions 54 to form a tee intersection therewith. The terminal pins 52 extend a short distance to a right-angle bend and further extend linearly from the bend orthogonally with respect to the wire terminating portions 54. Consequently, the base edge 58 of each wire terminating portion is elevated from the plane of the terminal pins 52 (see horizontal dotted lines). By elevating the base edges 58 of the wire terminating portions 54 above the planes of terminal pins 52, and by further arranging the wire terminating portions 54 in tiers (by providing alternate contact terminals 50 of different lengths as described above), the pitch spacing between adjacent contact terminals 50 can be decreased. Specifically, a 0.39 pitch spacing may be accomplished with the disclosed configuration using contact terminals 50 of standard size. This is because adjacent wire terminating portions 54 may be offset and slightly overlapped with each other (as shown by the vertical dotted line) while still maintaining the proper minimum spacing therebetween. Since the terminal pins 52 are submerged in their respective channels 42, an intervening plastic wall of the terminal support block 40 separates and insulates adjacent terminal pins 52. Hence, the terminal pins 52 can also be closely spaced without danger of cross-talk, and the overall pitch between contact terminals 50 can be reduced. As shown in FIG. 4, a plurality of contact terminals 50 may be integrally stamped or otherwise formed on a break-away carrier. In addition, contact terminals 50 may be formed with anchoring barbs 56 which plow through the side walls of channels 42 upon insertion therein to provide a secure interference fit. The terminal block 40 is designed to accommodate the closely spaced contact terminals 50 without compromising the strength or stability of the connector 10. As shown in the cross-sectional view of FIG. 5, which is taken from the rear of the terminal support block 40 along the lines 5-5 of FIG. 2, the channels 42 are formed more deeply than and actually traverse cavities 44. Consequently, cavities 44 define two elevated shoulders 48 flanking the channel 42 for supporting the base edges 58 of the wire terminating portions 54 of contact terminals 50. This way, when contact terminals 50 are seated within respective channels 42, the base edges 58 are carried upon the shoulders 48 of the cavities 44, and the terminal pins extend downwardly into channels 42. The shoulders 48 of cavities 44 provide a secure foundation for base edges 58 of contact terminals 50, and this prevents the contact terminals 50 from twisting and/or collapsing when wires are inserted into the respective wire terminating portions 54 of contacts 50. Moreover, the terminal support block 40 is highly resistant to breakage. As shown in FIG. 6, once all contact terminals 50 have been assembled into the terminal support block 40, a plug housing 60 is slidably inserted onto the terminal support block 40 over contact terminals 50. Plug housing 60 is an open ended structure having a central opening which conforms to terminal support block 40. The interior surfaces of plug housing 60 (facing the terminal support block 40) may be formed with channels 64 opposite each of the channels 42 of support block 40. Channels 64 ease insertion of plug housing 60 onto terminal support block 40 over the terminal pins 52 of contact terminals 50. In addition, channels 64 may be gradationally formed with a deeper central groove. This insures that plug housing 60 does not scratch the plating of contact terminals 50 away in the critical central area during insertion on terminal support block 40. When plug housing 60 is inserted on terminal support block 40, it covers the channels 42 of terminal support block 40 near the cavities 44 to keep the contact terminals 50 captive. The wire terminating portions 54 of contact terminals 50 remain exposed rearwardly of plug housing 60 to provide free access, and the terminal pins 52 of terminals 50 extend through and protrude forwardly of plug housing 60. A flange 62 is provided around plug housing 60 to limit insertion. In addition, terminal support block 40 may be provided with flanking resilient clamping fingers 46 which engage plug housing 60 to thereby lock the two components together. As shown in FIG. 7, once the contact terminals 50 are seated in the terminal support block 40 and plug housing 60 has been inserted thereon, an electrical shroud 30 is inserted onto the plug housing 60 over the terminal pins 52 for protection of pins 52. In addition, shroud 30 may be formed or plated with a conductive layer to provide an electromagnetic interference (EMI) shield around the protruding contact terminals 50. Shroud 30 is inserted until it abuts flange 62 of plug housing 60, and resilient fingers or other means may be provided to effect a locking engagement. At this point, the connector assembly may be employed to terminate a multi-wire cable 80. The ends of each electrically insulated wire 82 carried in the cable is compressed within the notches of the wire terminating portions 54 of the exposed contact terminals 50, and the wire terminating portions 54 serve to pierce the insulation and complete electrical contact with the wire therein. Mass insertion of the wires into the wire terminating portions 54 of contact terminals 50 may be carried out in a conventional manner such as shown and described in U.S. Patent No. 5,079,827. Once the cable termination is complete, the terminated wires are secured to the connector assembly by a pair of panels 70, each panel being configured as shown in FIG. 8. Panels 70 are generally flat rectangular components having resilient clamping fingers 72 protruding downwardly from opposing sides. Clamping fingers 72 provide a locking engagement to terminal support block 40. One or more apertures 74 are provided adjacent each clamping finger 72. Apertures 74 allow insertion of a screwdriver or other tool to bias clamping fingers 72 outward, thereby detaching panels 70 from terminal support block 40. As shown in FIG. 9, each of the panels 70 engages the respective upper and lower surfaces of terminal support block 40 and is anchored therein by clamping fingers 72. Panels 70 sit flush behind flange 62 of plug housing 60. Each panel 70 covers the wire receiving portions 54 of contact terminals 50 to keep the contact terminals 50 captive within the respective notches 76. FIG. 10 is cross-section of a fully assembled double-sided connector as shown in FIG. 1 when viewed from the rear of the connector assembly. The stable restraint of the wire terminating portions 54 of contact terminals 50 within cavities 44 is apparent, as is the two-tier overlapping arrangement which allows a 0.39 pitch spacing. These advantages facilitate a higher density connector assembly without compromising strength, reliability, or cost effectiveness. Having now fully set forth a detailed example and certain modifications incorporating the concept underlying the present invention, various other modifications will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that within the scope of the appended claims, the invention may be practiced otherwise than as specifically set forth herein. ADVANTAGES OF THE INVENTION An advantage of the present invention is the positioning of wire-terminating portions of contact terminals in rows of cavities in a terminal support block so that the wire-terminating portions in one row are offset with respect to the wire-terminating portions in another row, and parts of the wire-terminating portions in the one row overlap with parts of the wire-terminating portions in the other row thereby spacing the wire-terminating portions close together. Another advantage of the present invention is the wire-terminating portions of the contact terminals being supported in the cavities of the terminal support block so that the wire-terminating portions withstand the insertion forces of the conductors within the wire-terminating portions.

Claims: An electrical connector comprising a terminal support block (40) having a plurality of channels (42) extending in parallel relationship towards a common edge of the support block, contact terminals (50) having wire-terminating portions (54) and terminal pins (52) each disposed in respective ones of said channels (42), said wire-terminating portions (54) being wider than said terminal pins (52), characterized in that said support block (40) has rows of cavities (44), the wire-terminating portions (54) being each disposed in respective ones of said cavities (44), that each of said cavities (44) has a tee configuration with a respective channel and includes shoulders (48) spaced above the respective channel (42) in communication therewith and the cavities (44) of adjacent rows are offset with respect to each other, that the wire-terminating portions (54) have bases (58) engaging said shoulders (48), parts of said wire-terminating portions (54) in one of the rows of cavities (44) overlap with parts of the wire-terminating portions (54) in the other of the rows of cavities (44) thereby spacing the wire-terminating portions (54) close together. An electrical connector as claimed in claim 1, characterized in that a plug housing (60) includes a central aperture and channels (64) in alignment with said channels (42) so that said plug housing can be positioned onto said terminal support block (40) to hold said terminal pins (52) captive within said channels (42, 64). An electrical connector as claimed in claim 2, characterized in that a shield (30) in the form of a shroud having an open front end is positioned onto said plug housing (60) and said terminal support block (40) substantially encircling said terminal pins (52). An electrical connector as claimed in any of claims 1 to 3, characterized in that said wire-tenminating portions (54) have central slots for receiving respective insulated conductors (82) therein and for piercing the insulation to make electrical contact with the conductor when inserted within the slot. An electrical connector as claimed in claim 4, characterized in that a cover panel (70) is latchably mounted on said terminal support block (40) for confining the conductors in the wire-terminating portions (54) and for confining said wire-terminating portions within the corresponding cavities (44) of said terminal support block (40).

Inventors: DAVIS WAYNE SAMUEL, WHITEMAN JR ROBERT NEIL, DAVIS, WAYNE SAMUEL, WHITEMAN JR.,ROBERT NEIL
Applicants: WHITAKER CORP, THE WHITAKER CORPORATION
Application year: 1993
Main classification: H01R9
IPC codes: H01R13, H01R12, H01R4, H01R24