Contact retention assembly

A contact retention assembly for an electrical connector in which the contact comprises a longitudinally split tubular body having outwardly projecting barbs on the wall of the body. The barbs have an interference fit with the wall of the contact cavity in the connector insulator to retain the contact therein. Overlapping tabs extend inwardly from the wall of the tubular body and cooperate to form an aperture therein. A tapered tool is inserted from either end of the contact into the aperture to cause the tubular body to contract and, thereby, release the barbs from the wall of the contact cavity. Thus, the contact may be removed from the cavity in the insulator without damaging the wall of the cavity.

BACKGROUND OF THE INVENTION 
This invention relates generally to an electrical connector and, more 
particularly, to an electrical contact for an electrical connector and 
means for releasably retaining the contact in a contact cavity in the 
connector insulator. 
For simplicity and economy, it is desirable to reduce the parts in an 
electrical connector to the fewest possible number. To this end, in the 
past, contacts have been retained in cavities in the insulator of an 
electrical connector by providing barbs on the contacts which have an 
interference fit with the walls of the cavities when the contacts are 
pushed into the cavities. The barbs prevent the contacts from being pushed 
out rearwardly from the insulator when the contacts engage with contacts 
on a mating connector member. It is often necessary to remove a contact 
from the connector insulator such as when a contact is damaged or is 
originally inserted into the wrong cavity in the insulator. The contact 
may be removed from the cavity only by pushing the contact rearwardly 
therefrom. Such removal causes the barbs on the contact to score the wall 
of the contact cavity. Since the wall of the cavity is damaged by the 
withdrawal of the contact, when a new contact is inserted into the same 
cavity, the contact retention strength of the assembly is substantially 
degraded. That is, the contact often will shift rearwardly in the 
insulator when it is engaged by the contact on a mating connector member, 
thereby adversely affecting the electrical engagement made between the two 
contacts. 
It is the purpose of the present invention to overcome the aforementioned 
problem by providing a contact retention arrangement for a contact having 
retention barbs thereon which allows the barbs to be disengaged from the 
wall of the cavity in which the contact is mounted so that the contact may 
be withdrawn from the cavity without engaging the wall thereof. 
SUMMARY OF THE INVENTION 
According to the principal aspect of the present invention, there is 
provided a contact retention arrangement for an electrical contact which 
comprises a tubular conductive body having a longitudinally extending slot 
therethrough so that the body is capable of radial contraction. Retention 
barbs are formed on the wall of the body for engaging the wall of the 
cavity in an insulator in which the contact is mounted. Means are provided 
on the wall of the contact body which extend inwardly to the interior 
thereof and define a tool-receiving aperture. Such means cooperates with a 
tapered tool which is pushed into the aperture from either end of the 
contact body causing the body to contract and, thereby, release the barbs 
from the wall of the cavity. As a consequence, the contact may then be 
easily removed from the cavity without scrapping the wall thereof. Hence, 
the same contact or a new contact may be inserted into the same cavity 
with the same contact retention strength being achieved. The contact may 
be stamped from a sheet metal blank and formed into the desired tubular 
configuration, thereby providing a one-piece construction which is 
economical to manufacture. Other aspects and advantages of the invention 
will become more apparent from the following description taken in 
connection with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to FIGS. 1 to 4 in detail, which illustrates the first 
embodiment of the present invention, there is shown an electrical 
connector insulator 10 having a contact cavity 12 therein extending from 
the front face 14 to the rear face 16 of the insulator. The cavity 
includes a forward cylindrical bore 17 and a larger diameter rear 
cylindrical bore 18 opening at the rear face 16. The bores define a 
rearwardly facing shoulder 20 on the upper wall of the contact cavity. A 
closed entry 22 is provided at the forward end of the cavity adjacent to 
the front face 14 of the insulator. A bevelled entrance way 24 leads into 
the closed entry opening 22 for facilitating the insertion of a pin 
contact on a mating connector member, not shown, into the bore 17. 
The contact of the present invention, generally designated 26, is 
preferably a socket contact, as shown. The contact comprises an 
electrically conductive, generally tubular, body having a forward socket 
contacting section 28, an intermediate retention section 30, and a rear 
termination section 32. The forward, intermediate and rear sections of the 
contact contain longitudinally extending slots 34, 36, and 38, 
respectively, which are aligned with each other. The forward section 28 of 
the contact is joined to the intermediate section by a short connecting 
web 40 and the intermediate section is joined to the rear termination 
section by another short connecting web 42. 
The diameter of the tubular intermediate section 30 is greater than the 
diameter of the forward socket contacting section 28, so that the forward 
end 44 of the intermediate section defines a forwardly facing shoulder 
which abuts the shoulder 20 on the wall of the cavity 12 when the contact 
is inserted into the cavity as seen in FIG. 1. With the contact so mounted 
in the cavity, the forward end 46 of the contact is spaced slightly behind 
the closed entry 22 formed in the insulator 10 and the intermediate 
retention section of the contact is mounted in the larger rear bore 18. 
The rear termination section 32 of the contact extends rearwardly from the 
rear face 16 of the insulator. 
The termination section 32 of the contact may take any desired form. For 
example, the termination section may be solder pot, a crimp pot, or an 
insulation displacing termination, as illustrated. The edges of the slot 
38 of the tubular rear section 32 of the contact provide insulation 
displacing, core penetrating jaws. The edges of the slot 38 diverge 
outwardly toward the rear end 48 of the contact to provide a tapered 
entrance 49 for a conductor to be inserted laterally into the slot 38. A 
second longitudinally extending slot 50 is formed in the tubular rear 
section 32 of the contact opposite to the slot 38. The slot 50 extends 
from the rear end 48 forwardly, but terminates short of the front end 52 
of the termination section 32. The edges of the slot 50 define insulation 
penetrating jaws. To terminate a conductor to the contact 26, the 
conductor is inserted into the slots 38 and 50 at an acute angle as 
indicated at 56 in FIG. 1. When the conductor 56 is pushed into the slots 
in this manner, the edges of the slot 38 sever the insulation of the 
conductor and penetrate the core thereof to make an electrical and 
mechanical connection thereto, and the edges of the slot 50 penetrate only 
the insulation on the conductor to provide strain relief therefor. 
The tubular forward socket contacting section 28 of the contact contains a 
second longitudinally extending slot 58. The slot 58 is opposed to the 
slot 34 and extends from the front end 46 of the contact rearwardly 
toward, but short of the rear end 60 of the contacting section 28. The 
slots 34 and 58 define two spring beams 62 and 64 each having a generally 
arcuate cross-section. The spring beams 62 and 64 are adapted to 
resiliently engage a pin contact on a mating connector member, not shown, 
which is inserted into the bore 17 through the closed entry opening 22. 
The socket contacting section 28 of the contact of the present invention 
may take other forms, if desired. 
The intermediate retention section 30 of the contact contains a plurality 
of outwardly projecting retention barbs 66. Three of such barbs are shown 
by way of example only. Obviously, a larger or smaller number of barbs may 
be provided, depending upon the retention strength required for the 
contact. Each barb has a generally arcuate surface 68 which tapers 
rearwardly and outwardly, and a rear transversely extending edge 70. Two 
of the barbs are provided on one side 72 of the tubular intermediate 
section of the contact, and the other barb is provided on the opposite 
side 74 thereof. The diameter of the intermediate section of the contact 
and the width of the slot 36 are chosen so that when the contact is pushed 
into the cavity 12 from the rear face 16 of the insulator, the arcuate 
outer surfaces 68 of the barbs 66 will cooperate with the wall of the rear 
bore 18 to cause the intermediate section 30 of the contact to radially 
contract so that the contact may be inserted into the bore without 
scrapping the wall of the bore. The contact is pushed forwardly into the 
cavity until the forwardly facing shoulder 44 on the termination section 
engages the shoulder 20. Rearward withdrawal of the contact from the 
cavity is resisted due to the fact that the rear transverse edges 70 of 
the barbs will dig into the wall of the rear bore 18 because of the spring 
action of the longitudinally split tubular intermediate retention section 
of the contact. Preferably, the rear bore 18 is chamfered adjacent to the 
rear face 16 of the insulator, as indicated at 76 in FIG. 1, to facilitate 
insertion of the intermediate section of the contact into the bore. Thus, 
by the retention arrangement of the present invention, the contact may be 
inserted into the contact cavity in the insulator without damaging the 
wall of the bore 18, yet the barbs 66 on the retention section of the 
contact provide a high retention strength which resists push-out of the 
contact from the cavity when it is engaged by a pin contact on a mating 
connector member, not shown. 
According to an important feature of the invention, there is provided means 
on the retention section 30 of the contact which allows the barbs 66 to be 
released from the wall of the bore 18 so that the contact may be freely 
removed from the cavity 12 without damaging the wall of the bore. Such 
means comprises two circumferentially extending strip sections 80 and 82 
which are stamped from the sides 72 and 74, respectively, of the tubular, 
intermediate section 30 of the contact and are bent inwardly to provide 
U-shaped central regions 84 and 86, respectively. Reference is made to 
FIG. 4 of the drawings which illustrate the developed sheet metal blank 87 
from which the contact 26 is formed. The blank contains two sets of 
parallel slots 88, 88' and 90, 90'. The areas between the slots provide 
the material from which the strip sections 80 and 82 are formed. The blank 
87 is formed to a tubular configuration and thereafter the areas of the 
wall between the slots 88, 88' and 90, 90' are deformed radially inwardly 
to provide the bent strip sections 80 and 82. The U-shaped central region 
84 of the strip section 80 is adjacent to the side 74 of the intermediate 
section of the contact while the U-shaped central region 86 of the strip 
section 82 is adjacent to the side 72. As best seen in FIG. 3, the strip 
sections 80 and 82 are longitudinally staggered so that the U-shaped 
central region 84 and 86 thereof overlap each other to define an aperture 
92, which is generally coaxial with the longitudinal axis of the tubular 
socket contacting section 28 of the contact, as best seen in FIG. 2. 
It is noted that the deformed strip sections 80 and 82 of the intermediate 
section of the contact define a pair of generally rectangular openings 94 
and 96 on the sides 72 and 74, respectively, of the intermediate section 
of the contact. The barbs 66 are formed in the sides 72 and 74 of the 
intermediate section of the contact by a stamping operation. It is noted 
that two of the barbs are located so that their edges 70 are adjacent to 
the openings 94 and 96. 
In order to release the barbs 66 from the wall of the rear bore 18 in the 
insulator 10, the operator holds the rear termination section 32 of the 
contact and, preferably, inserts a tool 100 in the form of a tapered pin 
from the front face of the insulator through the socket contacting section 
28 of the contact into the aperture 92 defined by the formed strip 
sections 80 and 82 of the retention section of the contact. Pushing the 
tapered end of the tool 100 into the aperture 92 causes the sides 72 and 
74 of the contact to contract, thereby releasing the barbs 66 from the 
wall of the rear bore 18. While the tool is still held in the aperture 92, 
the operator then slides the contact 26 rearwardly out of the cavity 12, 
carrying the tool 100 with it, until the retention section 30 of the 
contact passes the rear face 16 of the insulator. Thereafter, the tool 100 
may be removed from the front end of the insulator. Thus, by this 
arrangement, the contact is withdrawn from the contact cavity 12 without 
damaging the wall of the cavity. As a consequence, the contact may be 
reinserted into the cavity, or a new contact mounted therein, and high 
contact retention strength will still be achieved. 
Reference is now made to FIGS. 5 to 8 of the drawings which illustrate the 
second embodiment of the contact of the present invention, which may be 
mounted within the cavity 12 in the insulator 10 in the same manner as the 
contact 26. The second contact, generally designated 102, is identical to 
the contact 26 except for the intermediate retention section 104. The 
retention section 104 has a tubular configurationn and is provided with a 
longitudinal slot 106 therethrough, like the termination section 30. A 
pair of tabs 108 and 110 are stamped from the sides 112 and 114, 
respectively, of the retention section 104 and are bent inwardly 
transverse to the longitudinal axis of the contact in adjacent overlapping 
relationship, as best seen in FIG. 7. The tabs 108 and 110 have openings 
116 and 118 therein which overlap but are misaligned to define 
therebetween a tool-receiving aperture 120. Retention barbs 122 are formed 
on the sides of the intermediate section of the contact, which function in 
the same manner as the barbs 66 on contact 26. The tool 100 may be 
inserted through the forward contacting section of the contact into the 
aperture 120 defined by the misaligned holes 116 and 118 causing the sides 
112 and 114 of the intermediate retention section of the contact to 
contract. Contraction of the retention section releases the barbs 122 from 
the wall of the contact cavity so that the contact may be removed 
rearwardly from the cavity in the same manner as the contact 26 is removed 
from the cavity in the first embodiment of the invention. FIG. 8 
illustrates the developed sheet metal blank from which the contact 102 is 
formed. The second embodiment of the invention has the advantage over the 
first embodiment in that it is somewhat easier and less costly to 
manufacture since it is easier to bend the tabs 108 and 110 inwardly than 
it is to form the U-shaped strip sections 80 and 82 of the contact 26. 
While the retention barbs on the contact of the present invention are 
preferably disengaged from the wall of the contact cavity by inserting the 
tool 100 into the forward contacting section of the contact, if desired, 
the tool could be inserted from the rear face 16 of the insulator through 
the tubular termination section 32 of the contact. Such rear release of 
the retention barbs would, of course, require the removal of the conductor 
56 from the termination section of the contact prior to the insertion of 
the tool 100 therein. Thus, the contact of the present invention may be 
released from either the front or the rear of the insulator, and is 
withdrawn rearwardly from the insulator after it is released. Since the 
retention barbs may be released from the front of the insulator, the 
present invention has particular advantage for those applications when 
access to the rear of the insulator is difficult, such as when flat cables 
are connected to the rear termination sections of the contacts in a 
connector. The invention has the further advantage that because only a 
small diameter tool is required to release the retention barbs of the 
contact, a closed entry may be provided for the forward contacting section 
of the contact. In addition, because the contact may be released from the 
rear of the insulator, the forward contacting section thereof may be in 
the form of a pin contact, as well as a socket contact. Finally, the 
contact of the present invention may be easily and inexpensively 
manufactured by conventional stamping and forming techniques and, 
therefore, is easily adapted to mass production manufacturing operations.