Small Pitch Dual Row Leaf Connector

The present invention relates generally to electrical connectors and more particularly relates to a dual row leaf connector having multiple contact terminals of increased density.

Many electrical connectors, are well-known in the art, such as shielded I/O connectors. These I/O connectors typically include a male part, known as a plug, which interengages with a female part, known as receptacle, to establish a reliable electrical connection between electronic devices such as computers and the like. I/O connectors are characterized by a large number of terminals which accommodate multiple circuits, usually data transmission circuits in computers and these type of connectors are being used more often as "docking" style connectors suitable for instances for example, in which a notebook or laptop computer is mated with another CPU or monitor station.

Each male and female connector part contains a terminal block with a plurality of terminals which are connected to a like number of circuit wires. The terminals are typically arranged along the width of the terminal block and protrude into an engagement position on the block. The connector also include a protective exterior casing which encloses the wires and portions of the terminal block. A metal shell may also be provided which extends from the casing outwardly to enclose the terminal block and its associated terminals. This shell also defines a structure surrounding the terminals and which provides a mating surface for the male and female parts of the connector.

An I/O type of connector includes a preselected number of terminals which match the required number of output or input circuits of the electronic device. The electronics industry is constantly seeking to further reduce the size of electronic devices. As such, manufacturers seek to increase the number of circuits accommodated by a single connector which also reduces the need for additional connectors. This increase in the number of terminals has typically been accomplished in the past by reducing the lateral size, i.e. width, of each terminal or by reducing the spacing between terminals increasing the overall lateral dimensions of the connector itself.

This manner of increasing terminal density is not without disadvantages, because when the width of the terminals or the spacing therebetween terminals are reduced without increasing the width of the connector, the operational characteristics of the connector may be detrimentally affected because with thinner terminals, the probability of misalignment between terminals of the male and female connector parts increases. Additionally, as the number of circuits which a connector must handle increases, the need for a connector structure which holds the circuit wires in place on the connector also increases.

The present invention is therefore directed to a connector which accommodates an increased number of terminals and which overcomes the disadvantages set forth above. Accordingly, one object of the present invention is to provide an electrical connector which has an increased number of terminals in a given limited space without causing any adverse effect when the plug and receptacle members of the connector are mated together.

Another object of the present invention is to provide a reduced pitch dual row leaf terminal block assembly for use in an I/O connector wherein the terminal block has a pair of terminal supports, and each terminal support having upper and lower sets of terminals disposed thereon, each of the upper and lower terminal sets being further divided into two distinct groups, the terminals having wire engagement portions disposed on the terminal blocks rearwardly from contact blade portions of the terminals, the wire engagement portions of the upper and lower terminal sets being disposed in spaced-apart order lengthwise on opposing sides of the terminal supports, wherein the wire engagement portions of adjacent terminals are further staggered with respect to each other to reduce bunching of wires due to the reduced pitch of the assembly.

A further object of the present invention is to provide an improved I/O connector of reduced pitch wherein the connector includes a terminal block having a plurality of terminals disposed thereon, the terminals having an elongated contact blade portions extending longitudinally along the terminal block and wire engagement portions associated therewith in the form of wire displacement terminals and disposed rearwardly of the contact blade portions, the terminals further being arranged in two distinct groups on the terminal block, wherein the wire engagement portions of each distinct group of terminals are staggered between adjoining terminals and spaced apart between distinct groups of terminals, the terminal block further including means, in the form of cover plates which engage the wire displacement terminals to maintain wires in contact therewith.

Still yet another object of the present invention is to provide a terminal block assembly for use in I/O and other style connectors having an increased terminal density at a reduced pitch approaching 1 mm, wherein the terminal block assembly includes a plurality of terminals disposed thereon in a staggered arrangement and disposed thereupon at different elevations so that wires terminated thereto may lie in two rows, one above the other.

In order to attain these and other objects and advantages, the present invention provides for an electrical connector having a terminal assembly which includes a terminal block disposed within a protective exterior connector casing. The terminal block includes at least two terminal supports extending along the length of the assembly and having two distinct groups of terminals arranged on the upper and lower surfaces thereof. Each terminal includes an elongated contact blade portion and a hermaphroditic wire engagement portion at its rear end which permits the terminals to be used in substantially interchangeably fashions on either the upper or lower surface of the terminal block supports. The terminal groups are disposed on associated terminal supports of the terminal blocks and are spaced apart with respect to each other both laterally and longitudinally. The wire engagement sections of the terminals are likewise staggered in their position both along the width and length of the terminal block. The two groups of terminals are defined on each support surface by being spaced apart from each other lengthwise along the connector.

This structural arrangement advantageously permits the number of terminals to be increased without disadvantageously increasing the size of the electrical connector and further assures that reliable mating of the terminals of opposing interengaging male and female connector portions occurs when coupling the plug and receptacle together.

The connector may further include one or more cover plates which are applied to the terminal supports above the staggered wire engagement portions to maintain and press the individual wires together into engagement with the terminals of the connector. The cover plate arrangement facilitates quick connection of conductors of the wire cable to terminals of the connector member and accordingly, each cover plate may have a plurality of slots which engage the terminal wire engagement portions which also facilitates lateral arrangement of the conductors of the wire cable in alignment with the terminals of the connector.

In accordance with one embodiment of the present invention, the terminals include insulation displacement terminals as their wire engagement portions and which are arranged in a manner so that the wire engagement portions are staggered with respect to adjoining terminals in each group of terminals. This arrangement permits a significant reduction of the pitch of the terminals in each terminal group on the terminal supports to thereby increase the terminal density of the connector, without any significant increase in the lateral dimensions of either the terminals or connectors. A preferred width of the terminal is thereby retained so that the present invention also substantially reduces any misalignment which may occur between male and female terminals of opposing connector members as might be caused by decreasing the lateral size of terminals in an attempt to increase terminal density of the electrical connectors.

In accordance with another aspect of a preferred embodiment of the present invention, the terminal supports cooperate with a spacer held therebetween in the terminal block assembly. This spacer includes a plurality of spaced-apart land portions which extend in alignment with respective terminals in place upon the terminal supports. These land portions engage the terminals and assist in holding them in place on the terminal supports. The spacer still further includes a plurality of projections aligned with the wire engagement portions of the terminals. These protrusions provide support to the terminal wire engagement portions in order to prevent their displacement during wire assembly.

Furthermore, the positioning of the wire engagement portions of the terminals of one group spaced apart from those of an other terminal group associated with the same terminal support facilitates sequential connections of wire conductors of electrical cable to their respective terminal groups.

These and other objects, features and advantages of the present invention will be clearly understood through a consideration of the following detailed description.

In the course of the following description of the detailed description, reference will be made to the attached drawings wherein like reference numerals identify like parts and wherein:

FIG. 1 is a plan view, partially in section, of an electrical connector constructed in accordance with the principles of the present invention;

FIG. 2 is a longitudinal sectional view taken along line A-A' of the electrical connector of FIG. 1;

FIG. 3 is a longitudinal section taken along line B-B' of the electrical connector of FIG. 1;

FIG. 4 is an enlarged longitudinal section of the inset C which is circled in FIG. 3;

FIG. 5 is a cross-sectional view taken along line D--D of FIG. 4;

FIG. 6 diagram is a diagrammatic view illustrating how the terminals are arranged in a lateral fashion;

FIG. 7 is an exploded view, taken from above and illustrating the alignment and engagement of the lower terminal support intervening spacer and terminals; and,

FIG. 8 is a partial cross-sectional view of the terminal block assembly taken from the rear and through the intervening spacer and the terminal bed portions thereof which receive the interior set of terminals.

The present invention relates to electrical connectors such as I/O connectors which have interengaging plug and receptacle members. Either the plug or the receptacle may include similar structure in accordance with the principles of the present invention and obtain the particular benefits and advantages thereof. Therefore, the following description will be directed mainly to the plug member of such a connector.

FIGS. 1-3 illustrate an electrical connector 100 constructed in accordance with the principles of the present invention. The connector 100 includes a plug member P which is adapted to engage and effect an electrical connection with a receptacle or female connector member R. As seen in FIG. 1, the connector includes an exterior casing 10 and a multiple wire cable 19 extending therefrom at the rear portion of a casing 10. The cable is of a conventional shielded type having a outer insulation 112, and intermediate shielding portion 114 and an interior insulative portion 116 which substantially define the body of the cable 19.

The cable 19 is hollow and contains a plurality of conductive wires 6 which extend for the length of the cable 19 and free ends 25 of the wires 6 exit an open end 118 of the cable and enter the interior space 120 of the connector plug member P. The cable 19 is secured within the connector housing 10 by a suitable means, such as clamp 20. As will be explained in greater detail below and as illustrated best in FIG. 2, this interior space 120 serves as an enclosure for the cable open end 118, the ends of the cable wires 6, the connector terminal block assembly 122 and the connector bulkhead 119. These components are located within the space 120.

At the forward end of the plug connector P, a metal engagement shield 8 extends from within the connector interior space 120 outwardly to form a protective enclosure which surrounds the forward ends of the connector blades 3. This shield 8 engages the terminal block assembly 122 at lugs 140 and is held between the terminal block assembly 122 and the exterior casing of the male connector P. The shield 8 is spaced apart from the connector blades 3 and defines a space S into which a corresponding female connector member R fits, as illustrated in FIGS. 2 & 3.

The female receptacle member R is similar in structure to the male plug member in that it includes a casing 33 having means for engaging a circuit board, illustrated as posts 142 which are received by suitable openings in a printed circuit board (not shown). The casing 33 mates with a receptacle terminal block assembly 144 having a plurality of terminal supports 146 extending therefrom. These supports 146 may include channels or other suitable opening 148 which accommodate the receptacle member terminals 31. These terminals 31 are elongated and include, as illustrated in FIG. 2, free end portions 150 with suitable contact faces 152 disposed thereon.

The female terminal block assembly 144 may also have a metal shell 34 disposed thereon which surrounds the extending terminal supports 146 in order to provide an outer engagement surface thereto which may engage the interior of the male plug member metal shell 8 to form an effective and durable connection. In this regard, either shell 8 or 34 may include detents 154 to enhance the engagement between the male and female connector members P, R. The female terminals 31 preferably have tail portions 35 which extend out of the receptacle R for connection to circuit board traces such as by soldering or other suitable means. As is known in the art, the connector blades, or terminal support arms 3, of the male member P are received within corresponding slots 149 of the receptacle member R to establish a connection between the two connector components P and R.

Focusing specifically on the male connector member P, it can be seen from FIG. 2 that the free ends 25 of the wires 6 of the cable 19 are terminated to the terminal block assembly 122. This assembly 122 provides a foundation for a plurality of terminals 1 in order to hold them in place between top and bottom portions of the connector casing 10. The assembly 122 also engages an endwall portion 124 of the connector plug member bulkhead 119 and still further serves to orient the terminals 1 into a predetermined engagement position for proper electrical engagement with the corresponding opposing terminals 31 of the receptacle member R, when the two connector members P, R are mated together.

Turning now to FIGS. 2 & 6, it can be seen that each of the terminals 1 of the male connector member P includes an elongated contact blade portion 16 and a wire engagement portion, illustrated generally at 4, disposed on the terminal rearwardly of the contact blade portion 16. The wire engagement portion 4 is illustrated in the Figures as an insulation displacement assembly 126 which extends perpendicularly from the plane of the terminal contact blade portion 16 (or upwardly as illustrated in the Figures).

Each insulation displacement assembly 126 of the terminals 1 includes a pair of engagement prongs, or tines 14, which are separated from each other by an intervening slot 13. The slot 13 has a width which is slightly less than the diameter of the conductor portion 21 of the wire 6 so that when a wire 6 is pressed into the slot 13, the prongs 14 cut into its protective insulation 22 and pinch the conductor portion thereof 21, as is well known in the art. In order to assist entry of the wires 6 into the wire engagement portions 4, the prongs 14 thereof may include, as illustrated in FIG. 5, inwardly slanted surfaces 15 which direct a wire 6 under force into the central slot 13.

The plurality of terminals 1 of the present invention may be considered as including two distinct sets of terminals 2a, 2b associated with each of the two terminal block members 130, 132. Within these two sets, the terminals 2b which are arranged and received in the terminal bed portions 131 may be further considered as an "interior" set of terminals, in that in terms of the overall terminal block assembly 122, they are held between the two terminal block members 130, 132 and hence are disposed at the "interior" of the entire assembly 122. Likewise, the other sets of terminals 2a which are disposed on the outer wiring 143 surfaces of the terminal block members 130, 132 may be considered as an "exterior" set of terminals.

Returning to FIGS. 1 & 2, the terminal block assembly 122 is seen to include two interengaging terminal block members 130, 132 and an intervening spacer member 134 which is effectively sandwiched in the interior of the assembly 122 between the two terminal block members 130, 132. Each terminal block member 130, 132 includes a terminal bed portion 131, which as shown in FIG. 7, includes a plurality of slots 133 formed therein extending approximately lengthwise for the particular terminal block member bed portion 131. The block members 130, 132 may include suitable engagement means, such as posts 170 which are received in corresponding openings 171 of an opposing block member.

Each such slot 133 of the bed portion 131 accommodates a terminal 1 of the interior terminals 2b. Rearwardly of the slots 133, a series of recesses 135 are formed in the terminal block member 132, preferably in two parallel rows, which extend into the member 132 and open up on the opposite, or wiring surface 143 thereof. These recesses 135 receive the projecting insulation displacement assemblies 126 of the terminals 1 in such a manner that the two prongs 14 of each such assembly extend upwardly above the wiring surface 143 of the members 130, 132.

Although the terminals 1 include engagement edges 156 at their contact blade portions 16 which serve to engage the slots of the terminal bed portions 131, the intervening spacer 134 of the terminal block assembly 122 is preferably provided with a series of raised land portions 137 which extend outwardly from the spacer 194 which are aligned, preferably in a one-to-one correspondence, with the terminal receiving slots 133 and terminals 1 disposed therein. These land portions 137 effectively assist the slots 133 and maintain the terminals 1 in place upon the terminal member 132. The land portions 137 are disposed on each opposing surface of the spacer 134 in the same pattern spacing so as to render the spacer hermaphroditic, or reversible. That is, the spacer 134 has no unique orientation with respect to the terminal block members 130, 132 so that either surface of the spacer 134 may be used to engage either terminal block member 130, 132. In order to retain it in place in the terminal block assembly 122, the spacer 134 may include an engagement lug 138 or a rear wall thereof which is received within a slot of the terminal block members 130, 132.

In an important aspect of the present invention, the spacer 134 also preferably includes a plurality of extending projections 139 arranged in an array such that generally four projections 139 may be considered to be associated with each land portion 137. The array of projections 139 are spaced apart from each other longitudinally and are preferably positioned to match the staggered arrangement of wire engagement portions 4 of the interior sets of terminals of the terminal block member 130, 132, such that, as illustrated in FIG. 8, the projections 139 flank the terminal wire engagement portions 4 and support them as shown. The spacer 134 provides support for only the interior set of terminals of the terminal block assembly 122 and not to the exterior terminals disposed on the wiring surfaces 143 of the assembly 122. The spacer projections 139 are arranged in two spaced apart rows on the spacer 134 so that they will supportingly engage the staggered rows of terminals of the interior terminal sets 2b.

Returning to FIGS. 2 and 7, it may be noted that the interior and exterior sets of terminals 2b, 2a include free ends 17 on their contact blade portions which extend lengthwise out from the terminal bed portions 131 and are spaced apart from each other a distance which corresponds to the thickness of the terminal support arms 3. These free ends 17 are received upon the elongated support arms 3, which as illustrated in FIGS. 2 & 3, abut against the ends of the terminal bed portions 131 of the two block members 130, 132 and which extend from the connector bulkhead 119.

The bulkhead 119 includes openings 136 which accommodate the terminal free ends 17 and which lead to channels 141 which receive the terminal free ends 17 and portions of the contact blade portions 16 thereof such that the two terminal support arms 3 will establish a connection when they are received in the opposing engagement slots 149 of the receptacle member R.

In an important aspect of the present invention, the terminals 1 of the male connector member are arranged widthwise upon the terminal supports 3 in a lateral, staggered arrangement along the surface of the terminal support 3 illustrated in FIG. 1 and indicated by the line W therein.

Turning briefly to FIG. 6, the arrangement of the terminals 1 is diagrammatically illustrated wherein a group of four terminals 16 are shown in spaced-apart order with an intervening space d between adjacent terminals at the contact blade portions 16 thereof. The terminals 1 each have their wire engagement portions 4 (extending upwardly from the plane of the paper) arranged at their rear ends in a staggered fashion. That is, every other terminal is aligned along the width W of the terminal block assembly 122 to define one group of terminals while the remaining intervening terminal are aligned among themselves along the rear faces of their wire engagement portions 4 to define another distinct group of terminals set apart from the first group by the lateral spacing. Therefore, all of the terminals at their wire engagement portions 4, are spaced apart from each other a distance "e". In this manner, an increased density of terminals has been obtained resulting in desired pitches of approximately 1 mm.

Although the interior and exterior sets of terminals are disposed on opposing upper and lower surfaces of the terminal block members 130, 132, the wire engagement portions 4 of these two sets are located upon only one of these two surfaces of each block member. As illustrated in FIG. 2, the wire engagement portions 4 of the first terminal support 3 appear on the upper wiring surfaces 143 of the upper block member 130, while the wire engagement portions 4 of the lower block member 132 appear on the lower wiring surfaces 143 thereof.

In order to assist in reducing the pitch of the terminals 1, alternating terminals of each set of terminals 2a, 2b are folded upon themselves at 165 during formation of the terminals, such as by a suitable stamping and forming process. These folds occur at 165 and they permit the length of the terminals to be adjusted exactly prior to insertion into their respective channels of the terminal block members 130, 132. Certain of the terminals may also have a loop 167 formed therein for engaging the wiring surfaces 143 as well as locating the wire engagement portions 4.

As mentioned above, the terminals are also staggered along the length of the terminal block members 130, 132 in two distinct sets of terminals 2a and 2b which are separated into two distinct tiers of terminals appearing at different elevations of the terminal block members 130, 132 to present an overall stepped configuration. The terminals 2a are seen to lie upon the terminal block member top surface above the terminals 2b which abut the terminal block member lower surface. The wire engagement portions of these two sets of terminals as indicated by their respective insulation displacement prongs are further staggered lengthwise along the terminal block members. In this manner, the wires terminated to the upper set of terminals lie above the wires terminated to the lower set of terminals.

Each terminal block member 130, 132 preferably includes an abutment 160 disposed near its rearward end which facilitates the arrangement of the terminal wire engagement portions 4 at different tiers and which separates the two terminal sets 2a, 2b whereby the sets of interior terminals 2b have their wire engagement portions 4 rise on one side of the abutment 160 (shown to the left in FIGS. 2 and 3) and the sets of exterior terminals 2a have their wire engagement portions 4 rise on the other side of the abutment 160 (shown to the right in FIGS. 2 and 3). Cover plates 7a, 7b may be provided as shown to engage these staggered arrangements 5a, 5b. Each cover plate 7a, 7b is preferably provided with a plurality of slots 17 corresponding in number to the number of wire engagement portions 4 of the terminals 1 of each terminal support set. The cover plates 7a, 7b and their slots 17 are aligned with the engagement prongs 156 and subsequently snapped into place by way of engagement lugs 23 to ensure a reliable connection between the wires 6 and the insulation displacement terminals 4 and to retain them in place. The cover plates 7a, 7b may have their associated wires attached thereto, such as by lamination to form a single component so that the wires are terminated to the insulation displacement assemblies 126 when the cover plates are attached to the terminal block assembly 122.

It will be appreciated that the embodiments of the present invention discussed herein are merely illustrative of a few applications of the principles of the invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.