Electrical connector having contact retention means

A right-angle electrical connector comprises an insulator supporting a plurality of electrical contacts therein. The insulator includes a locator plate having a plurality of open faced slots with parallel, straight sidewalls for retentive receipt of the contacts therein. Each contact has a mating portion that is received in an aperture in the insulator, a retention portion received in the insulator slots and a terminal portion serving as a solder post for subsequent soldering to circuits on a printed circuit board. Each retention portion is of solid cross-section and preferably comprises a trapezoidal cross-section with its non-parallel edges defining relatively sharp barbs. During insertion the barbs engage the respective sidewalls in interference fit, deforming the sidewalls in a manner to retain the contact therein and to resist movement thereof in both the horizontal and vertical directions.

FIELD OF THE INVENTION 
The present invention relates to an electrical connector, and more 
particularly, to a contact alignment and retention system for right-angle 
electrical connectors. 
BACKGROUND OF THE INVENTION 
Right-angle, D-faced electrical connectors are used in the electronics 
industry as input/output (I/O) devices to interconnect a computer to 
external peripheral equipment. The contacts of the electrical connector 
are typically soldered to conductive traces on a printed circuit board at 
a backwall or panel of the computer. The front face of the connector, in 
addition to having the D-face for polarization, is mated with a 
complementary electrical connector which is attached to the peripheral 
equipment. The electrical contacts are supported in apertures in the 
insulative housing of the connector with the back ends of the contacts 
bent at right angles. Each contact terminates in solder posts which extend 
downward from the connector housing for insertion into through-plated 
holes in a printed circuit board (PCB) for subsequent soldering thereto. 
Maintaining the position and alignment of the projecting solder posts for 
ease of insertion into pre-formed plated through holes in a PCB has been 
recognized as a desirable feature of these connectors. 
Various approaches have been developed to maintain the contact solder posts 
in a pre-determined, aligned position. For example, one commonly known 
technique is to form the connector housing to have a slotted locator plate 
wherein the slots are formed as straight parallel-walled channels which 
receive U-shaped, resilient retention portions of the contacts in 
frictional engagement. U.S. Pat. No. 3,493,916 (Hansen) exemplifies this 
technique. 
U.S. Pat. No. 4,491,376 (Gladd, et al) illustrates another approach where 
the slots in the connector locator plate are formed to be narrower than 
the solder posts and which slots are configured to have recesses providing 
detents to retain the solder posts therein. Another slotted locator plate 
technique is shown in U.S. Pat. No. 4,789,346 (Frantz) wherein the locator 
plate slots are particularly configured to provide deflectable beams 
therebetween, the particularly configured slots receiving U-shaped 
portions of the contact therein. Still further, another approach 
addressing not only the maintenance of the contacts in a horizontal 
position but also in a vertical position is illustrated in U.S. Pat. No. 
4,842,528 (Frantz) wherein the U-shaped retention portion of the solder 
posts are particularly configured to have stop shoulders to engage the top 
or bottom surfaces, or both such surfaces of the locator plate in an 
effort to prevent vertical movement of the contact in the connector. 
Accordingly, it is desirable to provide an electrical connector wherein the 
terminal pins projecting therefrom for subsequent soldering to a printed 
circuit board are maintained in suitable alignment both horizontally and 
vertically and which also provides relative ease of assembly and effective 
costs of manufacture. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an improved electrical 
connector. 
It is a further object of the present invention to provide an electrical 
connector having improved structure for retention and alignment therein of 
the solder post portion of the connector contact. 
In accordance with the preferred form of the invention, an electrical 
connector comprises an insulator of insulative material including a body 
having a front face and a rear face with a plurality of contact receiving 
apertures extending therethrough. The body includes a locator plate having 
a plurality of slots each of which is defined by a pair of spaced, 
opposing sidewalls. Each slot opens adjacent the body rear face and 
extends toward the body front face. A plurality of electrical contacts are 
included, each contact having a mating portion, a retention portion and a 
terminal portion. Each mating portion is received in a respective body 
aperture. Each retention portion is received in interference fit in a 
locator plate slot. Each terminal portion projects outwardly from the 
locator plate. The contact retention portion of each contact has a solid 
cross-section and at least one barb having an exterior linear edge 
disposed obliquely relative to and in engagement with one of the slot 
sidewalls. Such exterior edge extends along the line converging with the 
sidewall in a direction toward the body rear face. 
In accordance with another aspect of the invention, there is provided an 
electrical contact for use in an electrical connector. In a preferred 
arrangement, the contact comprises a generally elongate conductive member 
having a mating portion at one end thereof, a terminal portion at the 
opposite end thereof and a retention portion therebetween. The retention 
portion has a solid cross-section and has a generally flat outside surface 
and a pair of spaced exterior edges each of which intersects the outside 
surface obliquely. Each such edge defines a respective barb for retentive 
engagement of the contact in an electrical connector.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Turning now to the drawing figures, there is shown in FIG. 1 a right-angle 
D-faced electrical connector 10 for mounting on a printed circuit board. 
Connector 10 basically comprises an insulator 12 and a plurality of 
right-angle electrical contacts 14. The connector 10 may comprise a 
conductive shell for protection against electro-magnetic or radio 
frequency interference (EMI/RFI) and hardware for attaching the connector 
to a complementary connector and for locking to a printed circuit board. 
Such shell and hardware are not shown in the drawings nor do they form any 
part of the instant invention. 
The insulator 12 is formed of insulative material, preferably being a 
molded, one-piece, thermo-plastic material and comprises a generally 
elongate body 16. The body 16 includes a front face 18 and a rear face 20. 
The insulator body 16 comprises a front nose portion 22 configured in the 
conventional D-shape for polarized connection to a complementary 
connector, a pair of opposed, spaced endwalls 24 and 26, a top wall 28 and 
a bottom wall 30. Projecting outwardly from the respective endwalls 24 and 
26 are mounting ears 32 and 34. Formed through the nose portion 22 are a 
plurality of apertures 36 which open through the front face 18 of the body 
16. A cavity 38 opening at the rear face 20 of the body 16 extends between 
the endwalls 24, 26, the top wall 28 and the bottom wall 30, cavity 38 
communicating with the apertures 36. Thus, apertures 36 are accessible for 
receipt of the contacts 14 therein through the cavity 38 opening at the 
rear face of the connector body 16. 
The bottom wall 30 serves as a locator plate for the contacts, as will be 
described in detail hereinafter, and has therethrough a plurality of slots 
40. Slots 40 open at the rear face 20 of the body 16, communicate with the 
cavity 38 and extend toward the body front face 18. Each slot 40, in the 
preferred arrangement, is defined by a pair of spaced, opposing, 
substantially parallel sidewalls 42. Each sidewall has in the preferred 
form, an inclined surface 44 which together define a wider opening of the 
slot a the rear face 20 to serve as an entrance guide for insertion of the 
contacts therein. The slots 40 may be formed to alternate between longer 
and shorter lengths extending toward the front face 18 of the body 16, as 
shown. 
Still referring to FIG. 1, the electrical contacts basically comprise a 
mating portion 46 at one end of the contact, a retention portion extending 
at a right angle with respect to the mating portion 46, and a terminal 
portion 50 at the other end of the contact 14. The mating portion 46 of 
each contact is received in a respective body aperture 36 and may have 
serrated edges 52 to provide secured receipt in such apertures 36. The 
contact retention portions 48 of the contacts are received in the slots 40 
in the locator plate 30, as will be described, at least two contacts being 
received in each slot 40. The terminal portion 50 of each contact projects 
downwardly from the locator plate 30 substantially perpendicularly 
thereto, each portion 50 serving as a solder post for subsequent soldering 
to plated-through openings in a printed circuit board. 
Turning now to FIG. 2, the details of the electrical contact 14 are more 
fully described. Contact 14 is comprised of a conductive metal, such as 
phosphor bronze. Preferably, for ease of manufacture, contact 14 is formed 
as a one-piece, integral member, stamped and formed from a sheet of such 
metal. As illustrated, contact 14 is of generally elongate structure and 
formed at a substantially right angle such that the terminal portion 50 
extends generally perpendicular to the mating portion 46. As shown, the 
mating portion 50 during manufacture may be attached to a carrier strip 54 
which is subsequently severed before the contact 14 is in use. The mating 
portion 46 is shown as a female socket comprising a pair of spaced tines 
56, 58 but, may also be a male pin. Attached to the contact mating portion 
46 is a shank 60 of solid, generally rectangular cross-section. The mating 
portion 46, in the preferred arrangement shown, is rotated 90 degrees with 
respect to shank 60 through a twisted neck portion 62. The shank 60 is 
bent at knee 64 to provide the right angle bend of the terminal portion 50 
relative to the mating portion 46. 
Extending downwardly from the shank 60 is the contact retention portion 48 
which, in the preferred embodiment is formed of a solid cross-section of 
trapezoidal shape. At the contact retention portion 48, the contact 
comprises a pair of spaced, opposing, substantially parallel, flat outside 
surfaces 66 and 68. Non-parallel, linear exterior edges 70 and 72 
intersect obliquely the flat surfaces 66 and 68 and together therewith 
form the trapezoidal cross-section. Edges 70 and 72 are formed to lie in 
respective directions that converge toward each other and that converge 
toward the flat surface 66 which faces contact mating portion 46. 
Extending above the exterior edges 70 and 72 and communicating with the 
side edges of the shank 60 are a pair of spaced, curved recesses 74 and 76 
extending into the contact at both sides thereof. Extending below exterior 
edges 70 and 72 and communicating with the contact terminal portion 50 are 
a pair of spaced, curved recesses 78 and 80 extending into the contact at 
both sides thereof. The contact terminal portion 50 is of solid 
cross-section and, in the preferred form, comprises a generally circular 
cross-section for enhanced stiffness for insertion into a printed circuit 
board. The curved surfaces of the upper recesses 74 and 76 merge with the 
curved surfaces of the lower recesses 78 and 80 to define the exterior 
linear edges 70 and 72, respectively. Edges 70 and 72 are each formed to 
be relatively sharp and serve as a barb to retain the contacts in the 
locator plate slots as will now be described by further reference to FIG. 
3. 
The contact retention portion 48 at the location of the barbs 70 and 72 is 
formed such that the width of the outside surface 68 thereat is of greater 
dimension than the spacing, s, between the sidewalls 42 defining each slot 
40. The width of the opposing outside surface 66 at the location of the 
barbs 70 and 72 is preferably formed to be of dimension less than the 
spacing, s, between the sidewalls 42 of a respective slot 40. Thus, upon 
assembly of the contacts 14 to the insulator 12, the contact mating 
portions 46 are inserted into the body apertures 36 and the contact 
retention portions 48 are slid into the locator plate slots 40. Flat 
surface 66, during insertion of the contacts 14 defines a leading edge of 
the contact while opposing flat surface 68 defines a trailing edge. During 
insertion, linear edges 70 and 72 of the barbs lie obliquely relative to 
the opposing sidewalls 42 such that each edge 70 and 72 converges with a 
respective sidewall in a direction toward the rear face of the insulator 
body. During insertion, the edges 70 and 72 of the barbs engage the 
sidewalls 42 adjacent the trailing edge 68 of the contact retention 
portion. Inasmuch as in the preferred form the width of leading edge 66 is 
less than the spacing, s, between the sidewalls, the edges 70 and 72 
adjacent the leading edge 66 will not engage the sidewalls. As the 
cross-section of the contact retention portion 48 is solid, the edges 70 
and 72 will scrape or deform the opposing sidewalls 42 causing an 
indentation 82, as illustrated in FIG. 3, in the respective sidewalls 42. 
As the curved surfaces of the recesses 74, 76, 78 and 80 are spaced from 
the respective sidewalls 42, a biting engagement of the barbs sharp edges 
70 and 72 is achieved. Such a biting arrangement into the locator plate 
slots maintains the contact 14 in intimate retention with the slot 
sidewalls thereby providing resistance to horizontal motion in the X, Y 
plane, and to vertical motion in the Z plane. Also, as the slots 40 are 
formed in a relatively straight fashion without complicated, profiled 
recesses, manufacture is simplified. Furthermore, as the locator plate 30 
is formed as an integral one-piece structure with the body 16, assembly of 
the contacts is simplified with the use of fewer parts. 
Having described the preferred embodiment of the invention, it should now 
be appreciated that other variations may be made thereto without departing 
from the contemplated scope of the invention. For example, while the 
preferred cross-section of the contact retention portion has been 
described herein as being trapezoidal in cross-section, other solid 
cross-sections may be considered, such as triangular and polygonal, 
provided the linear edges defining the barbs converge toward each other in 
a direction of insertion toward the front face of the connector. As such, 
the preferred embodiment described herein is intended to be illustrative 
rather than limiting, the true scope of the invention being set forth in 
the claims appended hereto.