Electrical connector plug with receptacle assembly

An electrical plug and receptacle assembly in which the number of different parts is minimized, is characterized by the use of an identical insulator in both the plug housing and the receptacle housing. The insulator has contact compartments adapted to mount either male or female contacts. Both the male and female contacts include an integral cable terminal. Additionally, the female contacts are segmented and include spring means for biasing the female contacts into tight engagement with male contacts. A cable clamp is also provided with the plug assembly which can effectively clamp either round or flat cables.

BACKGROUND OF THE INVENTION 
The present invention relates to an electrical connector plug and 
receptacle assembly, and in particular relates to such an assembly for 
high current applications in which manufacturing and inventory costs are 
reduced. 
Electrical connector plug and socket assemblies are used in a variety of 
applications where it is desirable to facilitate configuring the plug and 
receptacle assemblies to the number and type of electrical conductors in 
the cable within which they are associated, while minimizing the number of 
different parts associated with making up the plug and receptacle. 
Further, it is desirable to facilitate repair of defective portions of 
plug and receptacle combinations, while minimizing the number of repair 
parts that must be carried in inventory. This is particularly true in high 
current applications, such as in power distribution systems for 
distributing power to mining equipment and the like. At the same time, 
while minimizing the number of parts required for the plug and receptacle, 
it is very important in such high current applications to insure low 
resistance electrical connections, so as to prevent hot spots and the like 
developing due to the presence of the high current. 
BRIEF SUMMARY OF THE INVENTION 
Accordingly, it is an object of this invention to provide a plug and 
receptacle combination in which the number of necessary different parts 
are minimized. 
It is another object of this invention to provide a plug and receptacle 
assembly in which cable terminals are an integral part of the male and 
female inter-engagable contacts. 
It is another object of this invention to provide a plug and receptacle 
assembly in which identical insulators are used in the plug and 
receptacle. 
It is another object of this invention to provide an electrical plug in 
which a housing is formed of identical housing halves. 
It is another object of this invention to provide an electrical receptacle 
which includes female contact members that are segmented to assure 
multiple contact points to an interengagable male contact. 
It is another object of this invention to provide an electrical receptacle 
having generally U-shaped female contact members, with separate spring 
means being provided for urging the legs of the U-shaped portion to 
tightly grip a male contact. 
Briefly, in accordance with one embodiment of the invention, there is 
provided an electrical connector pair including a male plug and a female 
receptacle adapted for engagement to complete an electrical circuit. A 
male plug housing and a female receptacle housing are provided. Two 
identical insulators are provided, each insulator having a plurality of 
contact compartments. Means are provided for securing a first one of the 
insulators in the male plug housing and the second one of the insulators 
in the female receptacle housing. A plurality of male electrical contacts 
are provided, each having at least one blade portion at one end and an 
integral cable terminal at the other end. Means are provided for mounting 
the male electrical contacts in respective ones of the contact 
compartments of the first insulator. A plurality of female electrical 
contacts are provided, each having at least one generally U-shaped portion 
at one end and an integral cable terminal at the other end. Means are 
provided for mounting the female electrical contacts in respective ones of 
the contact compartments of the second insulator. 
Other objects and advantages of the present invention will appear from the 
detailed description which appears hereinafter, taken in conjunction with 
the accompanying drawings.

DETAILED DESCRIPTION 
Turning now to a description of preferred embodiments of the invention, 
FIG. 1 illustrates an exploded view of one embodiment of a male electrical 
plug in accordance with the invention. The male electrical plug comprises 
two identical housing halves 11 and 12. These housing halves can be 
conveniently formed of a casting or the like, and production tooling costs 
are minimized by having the housing halves 11 and 12 identical. The 
housing halves are provided with recesses 11a and 12a for capturing a 
collar portion 13a of an insulator 13. The housing halves 11 and 12 are 
adapted to be secured together through means such as bolt 14 and nut 16 
passing through bolt holes such as 11b and 12b provided in the housing 
halves. In assembled form, the housing captures and mounts the insulator 
13 through cooperation of the collar portion 13a thereof with the recesses 
11a and 12a formed in the housing halves. 
Since the plug housing halves 11 and 12 are identical, means have to be 
provided for discriminating between the top and bottom of the plug so as 
to insure appropriate orientation of the plug when connecting it to a 
receptacle. To this end, a top determining portion 17 and a bottom 
determining portion 18 are provided as shown in FIG. 1. Means are provided 
such as bolt 19 and nut 21 for securing the top determining portion 17 to 
the housing half 11. Likewise, means are provided such as bolt 22 and nut 
23 for securing the bottom determining portion 18 to the housing half 12. 
As shown in FIG. 1, the top determining portion 17 includes a detent 
portion 17a. In a manner discussed hereafter, this detent portion is 
engagable with a bar provided as part of a receptacle for providing a 
pivot point for assisting engagement of the plug to a receptacle. 
As also shown in FIG. 1, each of the housing halves 11 and 12 includes a 
slot 11c, 12c. A pin portion 17b is provided on the top determining member 
17, and when the top determining member 17 is secured to the housing half 
11 the pin 17b sticks down through the slot 11c. Referring to the bottom 
determining member 18, it can be seen from an inspection of FIG. 1 that 
upon assembling the bottom determining portion 18 to the housing half 12 
the slot 12c is covered thereby. The bottom determining member 18 does 
have a raised latch portion 18a, which cooperates with a latch provided on 
a receptacle for latching a plug to a receptacle in a manner discussed 
hereinafter. 
As shown in FIG. 1, the insulator 13 is provided with a plurality of 
contact compartments, generally indicated in FIG. 1 by reference numerals 
13b, 13c, 13d, etc. One side of the insulator 13 has a keyway formed 
therein, generally indicated in FIG. 1 by reference numeral 13e. The 
keyway 13e is provided in the insulator 13 for engagement with the pin 17b 
on the top determining member 17. Provision of this pin and keyway insures 
that the insulator is assembled in the housing halves right-side-up. 
FIG. 1 illustrates a universal grommet 24 which can be provided for capture 
between the housing halves at the end where a cable enters the plug. The 
universal grommet can be of a rubber or plastic insulating material, and 
is shown in FIG. 1 as having stepped portions. To adapt the grommet to any 
size cable, it is only necessary to cut off the grommet at a stepped 
portion whose diameter matches that of the cable to which the plus is 
being assembled. Use of a universal grommet also aids in minimizing the 
number of different parts necessary for assembling plugs to different size 
cables. 
Considering now FIG. 1 in conjunction with FIG. 6, FIG. 1 illustrates the 
contact side of insulator 13 and FIG. 6 illustrates the cable terminal 
side of the insulator 13. A plurality of male electrical contacts 26 can 
be provided for mounting within the contact compartments of insulator 13. 
As shown in FIG. 1, each of the male contacts 26 includes a blade portion 
26a at one end thereof and an integral cable terminal portion 26b at the 
other end thereof. The male electrical contact 26 also include a generally 
cylindrical portion 26c provided intermediate the blade and cable terminal 
portions. The cylindrical portion 26c slidingly fits through openings 13f 
(FIG. 5) provided in insulator 13. A flange portion 26d is provided on the 
male electrical contact to abut the contact side of insulator 13 adjacent 
to opening 13f. 
As shown in the drawings, the integral cable terminal of the male 
electrical contacts 26 is generally in a T shape. As shown in FIG. 6, 
conductor clamps 27 are provided for assembly on to the T shaped cable 
terminal. The conductor clamps 27 have a bolt 28 threadably secured 
therein, and serve two functions. First, the dimensions of the conductor 
clamps 27 are such that its width is less than the top or bar of the T 
shaped cable terminal portion. In order to assemble the conductor clamps 
27 to the cable terminal portions, the bolt 28 is threaded out of the 
conductor clamp 27, and the conductor clamp 27 is oriented so that the 
diagonal dimension of its opening will permit it to slip over the top or 
bar of the T-shaped cable terminal portions. Then, upon properly orienting 
the conductor clamps 27, the conductor clamps are prevented from slipping 
off the cable terminal portions, with the bolts 28 being threaded into the 
conductor clamps 27 to maintain the proper orientation of the conductor 
clamps with respect to the cable terminal portions. The presence of the 
conductor clamps 27 also serves to capture the male electrical contacts 26 
in assembled relation in the insulator 13. When a conductor is assembled 
to any of the cable terminal portions 26b, the conductor is inserted into 
the conductor clamp 27 and bolt 28 is tightened down on the conductor, to 
assure positive contact between the conductor and the cable terminal 
portion 26b. 
The importance of the cable terminal portion being an integral part of 
contact 26 is twofold. First, if one of the contacts fails, it is very 
easy to replace the contact. Secondly, "hot spots", which have occurred in 
prior art constructions, are eliminated. Previous designs have utilized a 
threaded hole on the back of the electrical contact members into which a 
threaded stud is screwed. Then a cable terminal is screwed onto this stud, 
and held in place with one or more set screws. Both threaded joints are 
potential hot spots. In accordance with the present invention, since the 
cable terminal is an integral part of the contact, these potentially 
troublesome hot spots are eliminated. 
If desired, the prior art construction utilizing a threaded stud can be 
utilized for making connections wherein high current carrying ability is 
not necessary. Thus, in FIG. 1 there is illustrated a contact block 29 
into which one end of a threaded stud 31 is screwed. The other end of the 
threaded rod extends through apertures such as 13g in the insulator 13 and 
extends out the other side of insulator 13. A cable terminal 32 is screwed 
onto this other end of the threaded rod 31 and held in place with one or 
more set screws 33. 
Also, if desired, a ground clip 15 having a terminal portion 15a can be 
provided for grounding the plug housing. As shown in FIG. 1, this ground 
clip can be captured and retained between the insulator collar portion 13a 
and the housing half 11. 
Turning now to a consideration of FIG. 2, there is shown an exploded view 
of the female receptacle in accordance with one embodiment of the 
invention. As shown in the drawing, a female receptacle housing 34 is 
provided. An insulator 13 is provided which, in accordance with the 
invention, is identical to the insulator used in the male plug assembly, 
thus minimizing manufacturing and inventory costs. The insulator 13 is 
suitably secured in the housing 34 by means such as bolts 36, nuts 37, and 
clamping plates 38. 
The insulator 13 includes a keyway 13e, as before. The female receptable 
housing 34 is provided with a key in the form of a boss or pin 34a for 
engagement in the keyway 13e, so as to insure correct assembly of the 
insulator 13 to the housing 34. 
The female receptacle housing 34 can include a coverplate 39 which covers 
the receptacle when it is not engaged by a plug. The coverplate 39 is 
mounted to the receptacle housing 34 by means of a rod or bar 41. This rod 
or bar 41 serves two purposes. First, it obviously mounts the coverplate 
39. Second, the bar 41 is adapted to engage within the detent 17a of the 
top determining member 17 on the plug assembly shown in FIG. 1. This 
assures that the top of the plug assembly is mated with the top of the 
receptacle assembly, and also serves as a pivot point for facilitating 
inter-engagement of a plug with a receptacle. 
As also shown in FIG. 2, a latch member 42 is mounted by a pin 43 to the 
receptacle housing 34. A spring 44 can be provided surrounding the pin 43 
for spring biasing the latch 42. When no plug is engaged in the 
receptacle, the latch 42, which has a detent or recess 42a, engages a 
latch surface 39a on the cover 39, for securely latching the cover 39 in a 
closed position on the receptacle. When, on the other hand, the plug 
assembly of FIG. 1 is engaged in the receptacle assembly of FIG. 2, the 
raised latch portion 18a of the bottom determining member 18 is engaged in 
the recess 42a of latch 42. This securely locks the plug in assembled 
relation to the receptacle and prevents inadvertent dislodging thereof. 
FIG. 2 (and FIG. 7 as well) show details of the female electrical contacts 
which are provided in compartments of the insulator 13 in accordance with 
the present invention. The female electrical contacts 46 include at one 
end a generally U-shaped portion 46a and at the other end a T-shaped cable 
terminal portion 46b. In accordance with the invention, the cable terminal 
portions 46b are integral with the U-shaped portions 46a, and are 
separated by a generally cylindrical portion 46c. As shown in the 
drawings, in accordance with one embodiment of the invention, the legs of 
the U-shaped portion 46a are segmented. Further, each of the segmented 
portions is provided with its own spring means 47 for resiliently biasing 
the legs of the U-shaped portion toward each other. By providing at least 
two segments to the female contact, the possible contact points between 
the female contact and the blade of an inter-engaged male contact are 
doubled, thus reducing the possibility of "hot spots" from the high 
current passing therethrough. 
As shown in FIG. 2, it is possible to include a threaded rod and contact 
arrangement as part of the receptacle in the same manner as provided 
before in connection with the plug assembly. Thus, FIG. 2 illustrates the 
case where a contact block 48 is provided which threadably is secured to 
one end of a rod 49. The other end of the threaded rod extends through 
apertures 13g in the insulator 13, and is secured thereto by the same 
arrangement as illustrated in FIG. 6, i.e. by a cable terminal 32 which is 
held in place with one or more set screws 33. 
The female electrical contacts 46 are retained in place on insulator 13 by 
the same means as are the male electrical contacts 26. Thus, FIG. 6 also 
serves as an illustration of the manner in which conductor clamps 27 and 
bolts 28 engage the T-shape cable terminal portions of the female 
electrical contacts to both retain the contacts in assembled relationship 
in the insulator 13, and also to make electrical contact between 
conductors and the T-shaped cable terminal portions 46b. 
Thus, what has been described thus far, is an improved plug and receptacle 
assembly in which the number of different individual parts necessary from 
a manufacturing and inventory standpoint is reduced by utilizing identical 
insulators for both the plug and receptacle assemblies. Further, the plug 
is assembled using identical housing halves, with top and bottom 
determining portions secured thereto for defining a top and bottom of the 
plug. Means are provided on the receptacle and plug to cooperate for 
pivoting the plug on the receptacle and latching the plug in place upon 
inter-engagement with the receptacle. Further, the cable terminal portions 
of the electrical contacts of both the plug and receptacle are integral 
with the contact portions, thus making it easy to change them in case of 
failure and serving to eliminate "hot spots" in the contact assembly. 
Further, the identical insulator which is used in the plug and receptacle 
has a key way therein, and means are provided on both the receptacle 
housing and the plug housing constituting a key or pin to insure correct 
assembly of insulators to the housings. 
Turning now to a consideration of FIGS. 9 and 10, there is shown another 
feature of one embodiment of a plug assembly provided in accordance with 
the present invention. This feature relates to strain relief at the end of 
the plug assembly (housing halves 11b and 12b) through which a multiple 
conductor cable passes. As shown in the drawings, the cable clamp 
comprises two clamp halves 51 and 52 as shown in the drawings. These clamp 
halves can be identical, and they each have one flat side 51a, 52a, with 
the opposite sides 51b, 52b being arcuate in shape. Each of the clamp 
halves is secured by means such as bolts 53 to the two plug housing halves 
11b and 12b. Means are provided such as bolts 54 and nuts 56 to tightly 
clamp the clamp halves 51 and 52 around the exterior of a cable passing 
therebetween. In accordance with the invention, FIG. 9 illustrates the 
orientation of the clamp halves 51 and 52 for clamping a round cable. 
Thus, in this configuration, the arcuate portions 51b, 52b clamp the 
cable. FIG. 10 illustrates the manner in which the clamp halves 51 and 52 
can be used to suitably clamp a flat cable. Thus, in the configuration 
shown in FIG. 10, each of the clamp halves 51 and 52 is rotated 
180.degree. from their positions in FIG. 9, so that the flat faces of each 
of the clamp halves face each other. This permits secure clamping of a 
flat cable therebetween. 
Since each of the clamp halves 51 and 52 provided in accordance with the 
invention is identical, again the number of parts is minimized from both 
the manufacturing and inventory standpoint. Moreover, since the clamp 
assembly shown in FIGS. 9 and 10 is universal, i.e., it clamps both round 
cables and flat cables, it is not necessary to either manufacture or 
inventory a number of different clamps suited for clamping cables of 
differing cross sectional configurations. 
Referring now to FIG. 11, there is shown an illustration of an alternate 
embodiment of male and female contact members. In FIG. 11, the male 
contact member 61 is provided with two blade portions 61a and 61b. In this 
embodiment the contact member is still provided with a T-shaped integral 
cable terminal portion 61c. The female contact member 62 is provided with 
three segmented members 62a, 62b and 62c, which define two U-shaped 
portions for receiving the blade portions 61a and 61b of the male contact 
member. As in the other embodiment, the female contact member is provided 
witn a T-shaped integral cable terminal portion 62d, and spring members 63 
and 64 are provided for resiliently biasing the legs of the U-shaped 
portions into tight engagement with the male contact blade portions. 
It should be apparent to those skilled in this art, from the foregoing 
discussion, that many variations in specific configurations of the plug 
and receptacle assemblies discussed above are possible without departing 
from the true spirit and scope of the invention. The above detailed 
discussion has been directed toward presently preferred embodiments of the 
invention, and it is not meant to limit the scope of the invention to 
these presently preferred embodiments.