Note: Descriptions are shown in the official language in which they were submitted.
1~9054S
This invention relates to wire termination systems
in which a wire to be held in a terminal may be held between
a pair of jaws or within sets of jaws. More especially it
relates to a method of forming generally U-shaped jaws in a
terminal without shortening the original terminal blank and
without rupturing the metal used therefor.
Terminal connectors of the type presently involved
are formed of highly conductive metal which typically is
shaped to provide an elongated channel. Insulation piercing
jaws are provided within and along the edges of the channel,
as disclosed more specifically in McKee and Witte Canadian
application Serial No. 214,478, filed November 22, 1974, and
McKee Canadian Patent 1,027,199, issued February 28, 1978. In
use, an insulated wire is forced into the channel so that the
jaws penetrate the insulation and forcibly contact the conductor
of the wire.
Terminals of the type here involved typically are
used where space is at a premium and miniturization is im-
portant, as in molded, insulating receptacles designed to
contain a large number of terminals. A primary examine is
in connectors for 50-wire telephone cables. In such recep-
tables the tolerances are close, frequently on the order of
just a few thousandths of an inch. In order to accommodate
such tolerances it has been recognized that the terminals
must be of precise uniform dimensions.
The dimensional accuracy is important to insure
proper configurations and spacings for very high reliability
of forming good electrical contact of the jaws with the
109~545
conductor of the inserted wire. High compressive strength
of the jaws also is important to maintaining the spacing
tolerances under the compressive stresses imposed by forcibly
inserting a wire when forming a termination, i.e., to avoid
compressive yielding or failure of the jaws. The compressive
stresses may be of a high order, as in relying upon a camming
or wedging action between the wire and the jaws to effect an
intimate gas-tight contact therebetween, and which may involve
forcible displacement or distortion of the material of the wire
conductor by that action. It is also desirable to maintain
the side and bottom walls integral with one another, and to
avoid deformation of the bottom wall which would increase the
required overall depth of the terminal.
All of the foregoing problems and requirements are
exacerbated by the small size of the terminals involved. Thus
there is very little material available for forming the
necessary configurations or to lend mechanical strength.
These factors require close adherence to designs providing
high stress capabilities relative to the inherent strength
~0 of the material available, including the geometry of the
designs. Finally, highly conductive materials must be used in
such terminals to maximize conductivity. However, practical
and economical materials meeting these parameters usually are
of low ductility and more particularly have a low to medium
elongation capability, e.g., 5% to 10%. This means that the
materials will not accommodate significant tensile stretching
without tensile cracking and failure.
It is an object OL this invention to provide methods
for forming terminals of the aforementioned type, and which
methods overcome the noted problems and meet the related
desirable parameters.
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1090545
Accordingly, there is provided: the method of
forming a wire contacting jaw in an electrical wire terminal
comprising: disposing a flat sheet of current conductive
metal upon a first ribbed die face and impressing a portion
of the sheet upon said face, forming thereby a first
depression in said sheet portion, moving the first
depression onto a second die face having ribbing therein of
deeper dimension than the first die face and impressing the
first depression deeper than the depth thereof formed on
the first die face, moving the first depression onto a third
die face having ribbing therein of deeper dimension than the
second die face and impressing the first depression deeper
than the depth thereof formed on the second die face, and
folding the sheet into an elongated wire receiving body
having a bottom and facing sides defining a wire receiving
channel wherein the first depression is disposed from
one of said facing sides.
Brief Description of the Drawings
For a complete understanding of this invention
reference should be made to the accompanying drawings in
which:
Fig. 1 is a top plan view of a section of a blank
of a flat metal sheet for use on a progressive die and
showing a series of terminals in various stages of formation,
Fig. 2 is a cross-sectional view of a portion of the
blank shown in Fig. 1, taken along the line 2-2 in Fig. 1,
disposed between a first ribbed die and a first mating die,
lQ90545
Fig. 3 is a perspective view of a broken away portion
of the blank shown in Fig. 1, at approximately the cross-
sectional portion shown in Fig. 2, but showing the full width
of a terminal blank as indicated at bracket 3 in Fig. l;
Fig. 4 is a cross-sectional view of a portion of the
blank shown in Fig. 1, taken along the line 4-4 in Fig. 1,
disposed between a second ribbed die and a second mating die;
Fig. 5 is a perspective view of a broken away portion
of the blank shown in Fig. 1, at approximately the cross-
sectional portion shown in Fig. 4, but showing the full widthof a terminal blank as indicated at bracket 5 in Fig. l;
Fig. 6 is a cross-sectional view of a portion of the
blank shown in Fig. 1, taken along the line 6-6 in Fig. 1,
disposed between a third ribbed die and a third mating die;
Fig. 7 is a perspective view of a broken away portion
of the blank shown in Fig. 1, at approximately the
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109054S
cross-sectional portion shown in Fig. 6, but showing the full
width of a terminal blank as indicated at bracket 7 in Fig. l;
Fig. 8 is a perspective view of a completely formed
terminal separated from the blank shown in Fig. l;
Fig. 9 is a perspective cross-sectional view of a
plurality of terminals identical to that shown in Fig. 8, mounted
in a receptacle body frequently referred to as an insulating high
density connector body;
Fig. 10 is a cross-sectional and elevational view of a
pair of terminals ldentical to the terminal shown in Fig. 8 taken
along the line 10-10 in Fig. 9 and including a pair of insulated
conductor wires, not shown in Fig. 9, disposed for insertion into
the terminals; and
Fig. 11 is a cross-sectional and elevational view of the
pair of terminals shown in Fig. 10 illustrating insertion of the
wiresinto the terminals.
DETAILED DESCRIPTION O~ THE PREFERRED EM~ODIMENT
Considering first Figs. 1-7, the improved method of
making a terminal for use in a wire termination system is illustrat-
ed by showing successive steps in the formation of the terminal.Such terminals are especially useful as solderless terminations
in high density connectors, particularly those used in miniturized
electrical and electronic components. It will be recognized that
the metal used in the formation of such terminals, particularly
those of the present invention, is quite thin but only slightly
ductile. One especially suitable metal is cadmium bronze alloy
961 in 0.006 inch sheets. Ordinarily the tensile strength of this
material is on the order of 73,000 psi., and it has an elongation
capability of about 6-8%, preferably with a minimum of 7%.
10~0545
~ ig. 1 shows a series of terminal blanks of con-
ductive metal on which successivc steps of formation have been
carricd out in accordance with the present invention. A pro-
gressive die blank 2 is stamped to form foldable configurations
such as the configuration 4 which are ultimately folded into
terminals such as terminal 6. Sheet 2 may be as long as necessary
to fit both the stamping operation and the terminal forming dies
to be described later. Stems such as those shown at 8 and 10
maintain the foldable and folded configurations evenly disposed
througl-out the length of the metal blank. The stems 8 may be
finally severed, as at stem end 12, from a strip 14 at the
outer edge of blank 2, and the stems 10 may similarly be severed
from a strip 16 in the center of blank 2. A completely finishea
and separated ter~inal 6 is shown as 6A in Fig. 8.
As shown in Fig. 1, the center strip 16 of the metal
blank 2 includes a plurality of regularly spaced apertures 18
which function as an indexing means for moving blank 2, including
the foldable configurations 4, between terminal forming prosressive
die faces. It should be understood that although the foldable
configurations 4 are illustrated in Fig. 1 in individual and
successively more finished form from left to right, it is
possible to shape those configurations in groups having the
same form so that groups of the configurations 4 would bé
shaped identically. In that event the blank would be
adYancea more rapidly in accordance with the spacings of
the groups.
; Also, it will be noted that Fig. 1 illustrates forming
the foldable configurations 4 on both sides of the center strip
16 in blank 2. As viewed in Fig. 1, the configurations 4 below
.
,
~ _ ~ _
1090545
the strip 16 are ex~ctly identical to those located immediately
ab~ve them. Since~ the resulting terminals are used in
large numbcrs (a 2-1/8 inch long connector may contain as
many as fifty terminals, for cxample), it is desirable to
obtain high production rates. By duplicating the configura-
tions, and the steps involvcd in making them, on each
side of the metal blan~ 2, a number of terminals can be
made very rapidly with a minimum number of movements of
the metal blank and a correspondingly lesser unit cost.
hlhether the apertures 18 or other indexing means are
located along the center portion of blank 2 or along one edge
thereof, it is important that the metal blank 2 remain the same
width throughout as the blank progresses through the equipment
for forming the terminals. ~niform width and lack of distortion
of the blanl; in this respect insures that the shearing of the edge
strips 14 and center strip 16 from the stems 12 and 10 will result
in finished terminals of uniform dimensions. Such uniformity can
be achieved notwithstanding the formation of several impressed
undulations in the sides of the terminals, shortly to be
described. Formation of such undulations would be expected
to rupture the material or to cause deformation of parallel
connected flat portions of the blank. The former of course is
unacceptable and the latter would pull the outer edge portions
14 of the blank closer together, or distort the uniform linear
configuration of the center strip 16, and not only create a
substantial number of variations in the width of the blank but
also distrub the uniform oricntation of the components of the
terminals themselves.
The imprcssion of the undulations just referred to,
and to which the present invontion is directed, is particularly
illustratod at Figs. 2-7, ~u~ is best perceived with reference
.
B ~ `
1090545
to the fol~able configuration of the blan~ :a in ~ig. 1 and
the completely finished terminal 6A in Fig. 8. Confi~ur~-
tion 4a includc.s notches 20 and i5 flat except for impres-
sions and protuberances 22 and 24 which are not directly in-
volved in the present invention. Configuration 4a is formedas the result of preceding stampin~ steps perforned upon the
flat m~tal blan.t; 2. ~lso included in configuration 4a are
slots 26 (which alternatively may be sheared slits, ~ithout
removing material) and which are prc-ferably formed in pairs
opposite the notches 20, so that each notch is disposed along
the edge of the foldable configuration pointing at approxi-
mately the midpoint of a cor,panion severance 26. The por-
tions of each blank 4 comprising the sections between the
slots 26 and the respective blank edges together with ad-
joining sections at each end of those sections are formedinto jaws in accordance with this invention.
The end result of the desired shaping of configura-
tion 4a is shown in Fig. 8, a completed terminal 6A ready for
installation in a receptacle body such as an insulating hih
Bensity connector body. The stem ends 10 and 12 have been
appropriately severed, as by shearing, from the metal
blank 2. Side or panel portions 28 and 30 of the terminal
have been folded into upright parallel positions, at
approximately right angles to a terminal body base panel 32,
thus forming a narrow channel bod5~ 34 extending longitudinally
of the terminal. The notches 20, which have been beveled, are
disposed along the top edges of the sides 28 and 30, and slots
26 are disposed at the bottom edges at the junctions of the
~ides with the terminal body base 32. The jaws 36 extend
into the channel for contacting the electrical conductor
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1090545
of a wire to be disposed wi~hin the channel. Shoulders 38a
are provided at the junctures of the outer edges of the
jaws 36 with nominally planar portions 40a of the sides,
and shoulders 38b are forme~ at the junctures of the inner
edges of the j~ws with yoke portions 40b of the sides inter-
mediate the jaws.
By way of a more specific illustration, in a
terminal 6A for use in telephone wire connectors and in
the production of which this inventlon is particularly
advantageous, the channel body is about 0.050" wide
(outside dimension), about 0.058" high and about 0.40"
long from the outside of tab 174d to the near end as
seen in Fig. 8. Such terminals are formed of the afore-
mentioned 0.006" cadmium bronze alloy sheets and are used
lS in a solderless ribbon-type miniature connector made and
sold by TR~ Inc., Elk Grove Village, Illinois. Two pairs
of opposed jaws 36 are provided on 0.080" centers in each
terminal, with each jaw being about 0.022" deep from the out-
side surface of the respective channel side. Each jaw is
about 0.007" outside radius at the inner nose, and about
0.030" wide between the centers of curvature of the
junctions between its legs and the respective side
panel, which curves are of about 0.006" radius. Each
jaw is beveled at the top and tapers inward slishtly
therebelow, as seen in Figs. 8, 10 and 11. Each slot
26 is 0.040" long and separates the respective jaw
from the base panel 32.
The forming of the jaws 36 is accomplished in
steps which result in succes~ive forms of the jaw-forming
portions of the blanks as shown by the blanks 4b-4d in
B
1090545
Fig. 1 and illustrated cross-sectionally and in perspective
in Figs. 2-7. In Fig. 2 a portion of the side 28 of fold-
able configuration 4b from which a pair of jaws 36 is to be formed
is shown between a first ribbed die face 42 of a die 48 and a
first mating die face 44 of a die 46. Both die faces are
of configurations to include a plurality of ribs and valleys.
When the dies are moved together (as in Fig. 2 as by raising
or lowering the first die 46, depending upon orientation of
the die faces) the intervening two jaw-forming portions of
the blank are formed into two broad shallow depression or
wave configurations 50a and 50b by first ribs 52 on the die
face 44 and first valleys 54 in the die face 42. In this
initial step the mating dies are not closed on the blank
completely or "bottomed". The first depressions 50 are
shaped such that the metal configuration 4b is not ruptured
despite the fact that the material may have very limited
elongation capabilities. One of the prime objectives of the
first step is to form each depression 50 as the beginning
of a jaw by causing the metal to flow and stretch over the
longest available length of material by a minimum degree of
stretch in any one section without rupture of the material.
The initial shaping of the jaw portions of the
blanks, in the manner just described, results in a blank
with the shallow wave formation 56 of two depressions 50a
and 50b as shown in Fig. 3 (see also the left side of con-
figuration 4b in Fig. 1). These depressions extend the
full width of the jaw-forming portions, and are raised or
otherwise displaced from the plane of configuration 4b,
distorting one edge 58 of each of slots 26 while leaving the
B lo
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10905~5
other edges 60 generally co-planar with the terminal body base
32 which remains flat. The zenith or peak of each depression
50 is indicated by a dashed line 62 and is perpendicular to
a vertical plane containing the principal longitudinal axis
of the terminal body base 32. These peaks also coincide with
the edges of the notches 20 at their deepest and closest
penetration toward the distorted edges 58 of slots 26.
For the specific example given above, the shallow
wave forms created in the preliminary shaping of the jaws may
be obtained by using a die 46 having rigs 52 spaced on 0.080
centers, with outer ends of 0.015" radius and which protrude
0.20" from the otherwise generally flat face of the die.
Corresponding valleys 54 may be 0.042" wide and 1/32" deep,
with 0.019" radius shoulders at each side. It has been found
by using dies having such dimensions and the cadmium bronze
alloy metal to form a terminal, that there is some spring-
back of the metal depressions 50 when the ribbed die and
the mating die faces are separated. The depressions 50 are
pressed to a depth such that, after being released
from the dies, their inner depth is on the order of 0.010"
i.e., 0.016" to 0.018 outer height measured vertically from
the outer surface of their peaks to the opposite flat surface
of the side panel.
By approaching the formation of jaws 36 (see Figs. 7
and 8) gradually and over a maximum length, that is, by
separately performing the first step of making shallow wave
forms in the otherwise flat sides of the terminal blank in
the manner just described, the side portions 28 of terminal
6A tFig. 8) permit the creation of the wave forms therein
as demonstrated in Figs. 2-3 without distortion or shortening
of either base 32 or of
B ~/
the remai~der o~ ~he sides 28 ~nd 30 despit~ th~ fact that the
sides and base are integrally connected. Primarily, the
wave forms (such as depressions 50) are obtained by dispersed
stretching and in~low of metal from portions of the configura-
tion 4b adjacent but beyond the ends of the sections bet~7eenthe notches 2p and slots 26, as well as by dispersed stretch-
ing within those sections. Some displacement of the por-
tions of the blan~ intermediate the wave forms and the
notches 61 (Fig. 1, and which portions are about 0.020"
wide), apparently occurs as there is a change in the angle
of the adjacent edge of this notch as the depressions 50
are formed, compare blanks 4b-4d with blank 4a. However,
the same displacement is not available between the waves
or at the opposite end, where all of the blank remains
integral and the elongation must occur by stretching. The
stretching is not concentrated and is relatively uniform
throughout the metal being worked.
In examining the second step of crea~ing jaws 36,
attention should be given to Figs. 4 and 5 as well as to
confi5uration 4c in Fig. 1. The jaw-forming portions of
the blank, after having undergone the initial forming step
shown and described with respect to configuration 4b
in ~igs. 2 and 3, are placed between a second ribbed die
face 64 of a die 68 and a second mating die face 66 of a
die 70. The blanks are located with the previously-formed
depressions 50 centered on ribs and valleys of these die faces
to be described. Preferably these dies are then fully closed
(~bottomed") against the blank to reform and modify the pre-
liminary shapina of the terminal side panel in the areas in-
cluding the deprcssions 50, as shown for example in Fig. 4.Thereby, a number of significant modifications are made to
reform the depressions toward their ultimate jaw form.
/2 1090545
B ~
- 10905~5
Referring to the die surfaces adjacent the de-
pression 50a, as shown in Fi~. 4, the die face 64 includes
a second valley 72. The sides 74 and 76 of the second
valley 72 converge toward each other as they extend into
the body of die G8. At their outermost extrem;ties, ad-
jaoent the face 64 of the second ribbed die, these sides
are closer together than the sides 78 and 80 of each
valley 54 a~ viewed in Fig. 2. At each of those extremities
first shoulder ribs 82 and 84 are formed upon the second ribbed
die face 64, extending outwardly beyond the generally flat
plane of that die face. These ribs provide surfaces
which cooperate with first shoulder recciving grooves 86
and 88 in the second mating die face 66 for forming
shoulder impressions 90 and 92 in the blanX 4c. Similarly,
a rib 94 between the grooves 86 and 88 matès with the
valley 72 for reforming the center segment of the depression
50a. The second valley 72 and rib 94 are so dimensioned
that the depression 50a may be further deepened within
valley ?2 from the preliminary depth of that depression
achieved between the first ribbed die face 42 and the first
mating die face 44.
In order to insure the reverse curvature (from the
curvature formed at the depth of depression 50a) for
the formation of shoulder impressions 90 and 92, the
face 64 of the second ribbed die 68 may be provided
with a shoulder return face portion 96 adjacent the
outer extremity of rib 84. A similar shoulder return
face portion 98 may be provided adjacent the outer
extremity of shoulder 82. The shoulder return face
portions 96 and 98 in die face 64, and cooperative
shoulders 100 and 102 of the face 66, serve to return
lC~ /3
D
~090545
the adjacent portions of thc respcctive side pancl
to its normal pla~e relative to the jaw deformations.
The described ribs, shoulders and valleys
of die faces 64 and 66 are duplicated for reforming
5 of the depression 50b in the same manner as described for
depression 50a, as indicated by the parts identified by
the same numerals with a subscript a. I~owever, when
it is desired to provide a plurality of jaws 36 in a
side panel, as shown, the formation of the shoulder
face portions 98 and 102 will be slightly varied from
those of the face portions 96 and 100. As shown in
Fig. 4, adjacent shoulder return face portions 98 and
98a in the face 64 of die 68 merge with an intervenins
arcuate section 104 intermediate shoulders 82 and 82a.
~he center of this section is substantially co-planar
with the major face surface of die face 64. Such a
section 104 in cooperation with a corresponding portion
105 of the die face 66 which merges with surfaces 102 and
102a provides for a wa~e formation 106 in the side panel
between depressions 50a and 50b (which are to be finally
~ formed into jaws 36). The center of this wave is maintained
co-planar with the main body of the respective side panel.
The second mating die faces 64 and 66, as above de-
scribed, preferably are adapted to be bottomed against the por-
tions of blank 4c between those two die faces. Such bottominginsures proper formation of the various depressions and
shoulders of the blank, which occurs by reforming the blank
to the new configuration while coining and further stretching
the metal in the work area, as described further below. At
the same time, the remainder of the blank 4c is retained in
a flat undistorted form between other flat portions of the
dies.
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1090545
The rcsult of utilizing such co;nplementar~ die faces
as described with respect to Fiq. 4 is shown in Pig. 5, albeit
Fig. S, likc ~i~. 3, illustrates the use of four sets of die
faces rather than two sc's. Since Fig. 5 shows merely a further
step in the formation of terminal 6~ (see Fiq. 8), which step
is a further ~evelopment of the depressions shown in the frag-
mentary portion of the terminal illustrated in Fig. 3, it is
only necessary to identify the particular char,ges which have
occurred. Portions of each of the original depressions 50
have been xeformed as shoulders 90 and 92, extending on
the opposi,e side of the blank 2 from the central segments
of depressions. The two sides of each depression 50
have been formed much closer together and the depressions
themselves have been narrowed and deepened, with considerable
reduction in the included angle defined between these sides.
Of primary importance is the fact that the
terminal body base 32 has not been distorted or shortened
in any manner. The length of slots 2~ has remained
unchanged but despite the increased length of the metal
necessary for forming the depressions and adjacent shoulders,
the metal has remained unruptured.
The manipulation of the metal in the jaw-forming
portions to form the depressions and the shoulders in the
step of Fig. 4 includes reforming or reshaping of the
stretched wave form of Fig. 3. In addition, and simulta-
neously, controlled coining, that is, gradual, measured,
compressive forming of the metal is effected in the areas
comprising the shoulders 90, 90a, 92 and 92a as those
shoulders are formed, along with some additional stretching
of the metal throughout the portion being formed. The
,~ _ ~; _
10905~5
coining is effected in and adjacent the center portions or
bends of the arcuate end configurations of the impressions
90, 90a, 92 and 92a, between the outer end of each rib 82,
82a, 84 and 84a and the respective opposed groove 36, 86a,
88 or 88a. The metal is caused to flow into the convolu-
tions on the die faces under the influence of pressure
exerted through the die faces thus providing reshaping of
the metal and avoiding rupture of the metal during the
necessary lengthening and bending of the respective portion
of the blank to form the described configuration. Any
substantial concentrated or uneven tensile stretching of
the metal is avoided in order to obviate the possibility
of tensile fracture or failure, particularly at the tips
of the several bends created in the shoulder and depression
curved portions.
The above-described second step achieves quite
minute dimensions, especially in obtaining the reverse
curvatures provided by the shoulders in each side of each
initial depression 50. Whereas, in forming the depressions
50 initially (see Fig. 2), the first rib 52 on the first
mating die face 46 may impress each depression 50 into a
valley 54 which measures 0.042" wide even at its deepest
point, in the second, coining step (see Fig. 4), each de-
pression 50 may be impressed into a valley 72 which may
measure only about 0.025" where left and right sides 74
and 76 join shoulders 82 and 84, respectively.
Depressions 50a and 50b, as viewed in Fig. 5,
include convex curvatures having their peaks along zenith
line 62. Looking at the same face of sides 28 and
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30, reverse, or concave, curvatures are formed at the
shoulders 90, 92, 90a and 92a which extend from the
outside edgcs of the jaw-forming portions 50a and 50b
to the slots 26. The nadirs of these shoulders are
approximately ali~ned with the ends of the slots 26,
as illustrated by dashed lines 112 and 114. A dashed
line 116 designates the zenith of the arcuate t-ave
formation 106 intermediate the shoulders 92 and 92a,
which zenith extends perpendicularly toward an imaginary
line 118 aligned with the inside edges of slots 26.
The section 106 extends between an imaginary line 120
approximately at the outside edges of slots 26 to the
outer edge of the panels and is shaped to present a
convex surface on the same face of side 28 as the
convex surfaces of depressions 50, with the outer edges
leading downward to the shoulder ribs 92-92a. Creases
at 122 accommodate the offset of the outer portions of
shoulders 90, 90a, 92 and 92a.
The die faces 64 and 66 are of configurations
and dimensions to extend the overall height of the
jaw-forming port~ons to slightly greater than 0.018" ~-hen
$n the dies as in Fig. 4, as measured from the peaks of
portions 50 to the opposite peaks of shoulders 90 and 92.
Due to springback of the material, this height is
about 0.018" in the blank 4c of Fig. 5.
In addition to dimensions already noted, a set
of specific dimensions for die faces 64 and 66 for the spe-
cific example referred to above includes locating the
valleys 72-72a and ribs 94-94a on 0.080" centers.
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1090545
The valleys 72 and 72a may be of a 0.0135" radii
with their uppcrmost surfaces 0.007" above the
major flat surface (die line) of die face 64, and each
shoulder or rib ~2, 82a, ~4 and 84a may be of 0.0076"
radius with its pea~ 0.007" below the die line. The
shoulders 96, 96a, 98, 98a and intervening surface 104 all
may be of 0.025" radii, and are tangent at their upper
edges with the major flat surface (die line) of die
face 64. The centers of curvature of shoulders 82-84
and 82a and 84a are spaced 0.020" on the respective
sides of the centerlines of valleys 72 and 72a. Surface
104 is a continuation of the curvature of shoulders
98 and 98a and has its centerline midway between the
centerlines of the valleys. These various arcuate
surfaces merge directly tlith one another at common
tangent lines on the side of each rib, shoulder and
valley. Referring to die 'ace 66, each rib 94-94a
may be of 0.0076" radius with its outermost peak 0.007"
above the major plane of the respective die face. The
valleys 86, 86a, 88 and 88a may be of 0;0135" radii, each
having its center of curvature spaced 0.020" on the
respective side of the centerline of the related rib
and each extending 0.005" below the plane of the die
face 66. Shoulders 100 and lOOa are of 0.019" radii
and surface 105 is of 0.024" radius including shoulder
surfaces 102 and 102a, with each of these surfaces
extending tangent to the major plane of die face 66.
~hese various arcuate surfaces also merge directly with
one another at co~mon tangent lines.
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~09054S
As outlined above, Figs. 2 and 3 illustrate a
preferred initial step in the process of forming term~nals
6A, while Figs. 4 a~d 5 illustrate a preferred intermediate
step in formi~g such terminals. Figs. 6 and 7 illustrate a
preferred third step of terminal formation prior to folding
the sides of a processed configuration 4 into a completed
terminal 6~.
In Fig. 6 a third ribbed die face 124 of third
ribbed die 12~ is opposed by a third m~ting die face 128 of
third mating die 130. The processed portion of configuration
4c sho~m in Fig. 5 is positioned between the faces of the
third dies and is further formed thereby as in Fig. 6 to
produce the configuration 4d as shown in Pig. 7. Similarly
to the first processing step illustrated in Fig. 2, but
contrary to the intermediate processing step illustrated
in Fig. 4, the dies 126 and 130 are not fully bottomed
in the third processing step illustrated in Fig. 6.
The ribbed die face 124 includes a third
valley 132 having oppcsite sides 134 and 136 which
are generally parallel to each other. Curved second
~houlder ribs 138 and 140 connect the major planar
portions of the die face 124 with the sides 134 and 136,
reapectivelY, of the third valley. Otherwise the face
124 of the third ribbed die adjacent valley 132 lies
almost entirely in the same horizontal plane. The
valley 132, and more particularly the shoulders 133
and 140, is adapted to receive and further shape depres-
sio~ 50a following the processing of such depression
/~
B -~ -
~090545
bet-leen di~ faces 68 and 70 as in Fig. 4. When it is
desired to simultaneously process a plurality of adjacent
depressions, such as depressions 50a and 50b, a further third
valley 132a identical to valley 132 may be aisposed in the
third ribb~d die face 124. Li~e third valley 132, third valley
132a includes opposite sides 134a and 136a which are parallel to
each other. Curved second shoulder rihs 138a and 140a conn~ct
portions of the die face 124 with the sides 134a and 136a,
respectively, of third valley 132a.
The third mating die face 128 includes a third rib
projection 142 which has a rounded but much more sharply pointed
tip portion 144 than the end of rib 94 on the second matins
die face 66, shown in Fig. 4. Rib projection 142 is adapte~
to press depression 50 (see Fig. 6) between the narrowly
spaced apart second shoulder ribs 138 and 140 of the third
ribbed die face 124, ~hereby those shoulders press and coin
the sides of the depression against the sides of the rib 142.
The third rib projection 142 also extends much further ou'.~:ard-
ly from third mating die face 128 than does rib 94 of the
second mating die face. Accordingly, a depression 50 is
further deepened, or elongated, between the third die faces
124 and 128. A similar rib projection 142a may be formed
on mating die face 128, spaced apart fror.~ rib projection
142, when it is desired to process a plurality of depres-
sions, such as 50a and 50b in configuration 4d (see Fig. 1).
Face 128 of the third mating die 130 further com-
plements face 124 of the third ribbed die 126 in that the sides
of the third rib projection 142, namely, right side 146 and
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left side 148, as viewed in Fig. 6, are, for most of their
length, closer together than the sides 134 and 136 of vallcy
132. This relationship is maintained even though sides 146
and 14 R are angled to~ard each other as they approach tip
portion 144 of tlle third rib projection 142, while sides 134 and
136 of valley 132 are substantially parallel. Second shoulder
receiving cur~atures 150 and 152 are situated at the extremities
of the sides 146 and 148, respectively, of the third rib
projection 142, and these second shoulder receiving curvatures
merge with sides 146 and 148 at common tangent lines
where rib 142 is narrower than the valley 132 by an amount
exceeding tt~ice the thickness of the sheet material being
formed, i.e., the total width of the rib 142 at this
level plus a thickness of the material on each side would
be less than the width of valley 132. The surfaces 150
and 152 curve outward from these merge areas and are
tangent with th~ major planar surface of face 128 as
illustrated.
When it is desired to process a plurality
of depressions, such as 50a and 50b (see Fig. 6), the third
rib projection 142a is formed with sides 146a and 148a, and
second shoulder receiving curvatures 150a and 152a, disposed
identically with respect to valley sides 134a and 136a
and second shoulder ribs 138a and 140a, as the rib pro-
jection sides and shoulder receiving curvatures of rib 142
are disposed relative to valley 132.
As suggested above in describing the third ribbed
die face 124 as being almost entirely in the same horizontal
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plane, the face 128 of the third mating die 130 also lies
almost entirely in a horizontal plane, thus further
complementing the third ribbed die face 124 and the valleys
and shoulders formed therein. The disposition of the third
ribbed die face 124 and third mating die face 128 in horizontal
planes may correlate two yo~e forming portions on these die
faces, i.e., when a plurality of depressi~ns are to be
formed, a planar yoke-forming face portion 154 on die
face 124 joins the second shoulder rib 140 adjacent valley
132 with the further second shoulder rib 138a adjacent
valley 132a, and an oppositely disposed planar yoke-
receiving face portion 156 on the third mating die
face 128 joins the second shoulder receiving curvature
152 adjacent rib projection 142 with the further second
shoulder receiving curvature 150a adjacent rib projec-
tion 142a.
Relative to the dimensions of the die faces set
forth above with respect to the first ribbed and first
mating dies 48 and 46 and with respect to the second
mating dies 68 and 70, the faces of the third rib-
bed die and the third mating die may be dimensioned
as follows. The valleys 132 and 132a and the ribs 142
and 142a are spaced 0.080" on centers. Both of the valleys
132 and 132a extend inwardly into the third ribbed die
face 1/32", and their sides 134 and 136 as well as 134a and
136a are parallel to one another and disposed 0.017" apart.
Each of the second shoulders 138, 140, 138a and 140a has
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a radius of 0.006". In a complementary manner, the third
mating die face 128 is dimensioned so that each of the
rib projectio~s 142 and 142a extends outwardly from die
face 128 a di~tance of 0.016". The radius of each of the
tip portions 144 and 144a is 0.002" and the sides 146 and
148 for projection 142 and 146a and 148a for projection 142
diverge inward from the lines of tangency with the rounded tip
portion of each projection toward the horizontal plane of the
face 128 of the die, defining an included angle of 40 bisected
by a line normal to face 128. Each of the shoulder-receiving
curvatures 150, 152, lSOa and 152a is of 0.010" radius, and
the centers for each pair of these curvatures are s~metrically
disposed about the centerline of the respecti~e rib and are
spaced apart 0.029". Using such dimensions for the face of
die 130, the yoke-receiving face portion is 0.051" between the
centers of the shoulder-receivins curvatures 152 and 150a.
In the third step for further forming the jaws 36,
die faces 124 and 128 are engaged with a configuration 4c
i.e., ~ portion of side 28 previously processed as il-
lustrated in Figs. 4 and 5 and subsequently positioned
between die faces 124 and 128. These two die faces then
are closed on the blank as in Fig. 6, but the dies
preferably are not bottomed.
Since substantially the same forming action
occurs in and around the second depression 50b, it is
only necessary to specifically describe the third
step in forr..ing of depression 50a. The primary stress
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Insos4s
points arc in t}lC areas of cngagcment of the terminal blan~.
between the second shoulders 138 and 140 of ribbed die face
124 and the sc-cond shoulder-receiving curvatures 150 2nd
152 of th~ mating die face 128, as illustrated ~tith some
exagycration ln Fig. 6, and in the engagement of tip 144
in the apex of th~ depression 50a. Coining of the metal
takes place in the side shoulder stress areas, bet~;een the
shoulders 138-140 and the curvatures 150-152, apparently alor.g
with some further stretching of adjacent portions of the blank,
to provide additional length in the jaw-forming portion for
further deepenins and for narrowing of the depression 50a.
Moreover, these areas of coining are shifted slightly inward
and upward of the shoulders 90 and 92 from the coining of
the preceding step, and the stretching is distributed, to
avoid tensile rupture of the metal. Simultar.eously
there is further stretching and further forming of the
metal over the nose 144 to further distribute the stretch-
ing and further forming stresses, l.e., in extending
the depression around tip portion 144 of the third rib
projection 142. In the latter regard, it will be noted
that the rib 142 is slightly higher (0.016") than the
vertical dimension of the depression 50a of the blank 4c
resulting from the preceding step. Allowing for some
springback of the metal used, the depression 50a is
lengthened to approximately 0.022" (outside height
dimension) in the blank 4d.
Because die faces 124 and 128 are not completely
bottomed, shoulders 90 and 92 of blank 4c are not completely
eliminated in the further forming of blank 4d, but
remain in part as slight residual shoulder ridges 158
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and lG0 (~i~s. G ana 7) o~ thc con~iguration of final
should~r forms 3~a and 3~b ~Fig. 8). Correspondingly,
neither are the shoulder return portions completely
eliminated, since they are presscd into the modified,
final forms 162 and 164 of side 28. When more than one
depression in side 28 is desired, the wave formation
106 of blank 4c (Fig. 5) is substantially flattened
to ~orm yo!~c 166 (Figs. 6 and 7) between the terminuses
of shoulder return portion 164 and an adjacent
shoulder return portion lG4A associated ~ith depression
SOb. In the preferred form of the terminal formins
process or method of the present invention, described
above in terms of the dimensions of dies used in the
specific illustrative process, the distance bet~7een the
outermost surfaces o. the shoulders 158 and 160 and
the corresponding outer face plane of yoke 166 and the
remainder of side panel 28 will generall~ be only a few
thousandths of an inch in the blank 4d (Fiss. 6 and 7)
and in the ultimate folded form of terminal 6A (38a and
38b in Fig. 8).
It should be particularly noted that in the
~urther forming of blank 4d from blank 4c, as described
with reference to Pig. 6, not only is each depression 50
deepened, but also its sides are brought closer together
and straightened somewhat, more nearly approaching posi-
tions normal to the plane of the respective side panel
28 or 30. Correspondingly, the shoulders at the base
.of each depression 50 are formed closer together and
their radii of curvature reduced, thereby minimizing the
distance between their nadirs or support peaks, i.e., the
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shouldcr ri~ge surfaccs opposite thc dashed lincs 170 and
172 in Fig. 7. The net result is to provide jaws 36 which
are of a geometry to withstand large compressivc forces
applied outwardly on their noses 176 and resisted by support
forces occurring primarily at the ridge lines 170 and 172.
The ribs 142 also may be of appropriate configuration to
provide a slight converging taper of the resulting jaw
noses from the upper ends to the lower ends in the terminal
6A, as best seen in Figs. 10 and 11.
After the final formation of the depressions
to form the jaws 36, as in blank 4d, the foldable
configurations 4 may be shaped in other respects to
arrive at the final terminal form of Fig. 8. Among
such steps are coining of the angular top surfaces of
the jaws (which have resulted from the notches 20)
to provide a smooth beveled surface on each jaw for the
wire-engaging functions, folding the sides 28 and 30
approximately perpendicularly to the terminal body base
32, folding tabs 174a, 174b, 174c and 174d (Fig. 8) into
their proper positions, and severing stems 8 and 10
- from the metal blank 2. Stem 8 is bent to its bow
form, and its distal end 8a lS bent into a U-shaped
configuration, to form the completed terminal 6A.
Jaws 36, the completed result of the formative steps
performed upon depressions 50, are accordingly disposed
along at least one side, and preferably both sides 28
and 30, of the terminal 6A to extend inwardly over the
terminal body base panel 32. In the form of the terminal
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6A shown in Fig. 8, two pairs of jaws 36 are disposed in
the sides 28 and 30 so that the jaws extend toward each
other and the tip portions 176 are positioned in opposition
to each other.
When the completely formed terminals 6A have been
severed from the metal blank 2 and finally formed into their
ultimate configurations they may be mounted in a molded,
insulating receptacle 178, such as shown in Fig. 9. Without
describing the receptable 178 in great detail, it may be
noted that it includes a plurality of generally channel-shaped
passages 180 into which the terminals 6A may be inserted.
The U-shaped distal end 8a of each terminal may be hooked
about a rib 182 or 182a on one side of receptacle 178 as
each of the terminals is inserted into a passage 180, and
tabs 174c are bent up to the locking portion of Fig. 9.
Vertical passages 184 permit access to be had to each
channel 34 running through the body of each terminal 64
in a passage 180. The sides 186 of each passage 180 are
disposed so that the shoulders 38a and 38b of each terminal
are closely fitted against them, and the shoulders may
~therefore provide the primary support force transfer from
the jaws 36 to the sides 186 for supporting the jaws 36
against outward deformation of the jaws which might other-
wise result from forcible insertion of wfres against the
jaw noses 176. In order to obtain the close fitting engage-
ment of the shoulders against the sides of the passages
180, it is important that the widths of the terminals and
the widths of the passages be precisely dimensioned.
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Ref~rring now particularl~ to Figs. 10 and 11,
the inscrtion in~o the receptacle of wires to carry
electrical currcnt, and fixing them there, normally
is accomplish~d by forcing the wires 188, including a
center conductor 189 and an insulation covering 190,
laterally of their axes through the vertical passages
184 into the inclined surfaces defined by notches 20
of jaws 36 and between the noses 176. A tool blade 192
is shown above each wire and having an end surface to
force each insulation-co~ered wire between a set of
jaws 36. If a plurality of wires 188 are to be inserted
substantially simultaneously, the tool may comprise
a plurality of blade faces 194. As each ram face 194
is forced downwardly, it forces-one wire 188 between
jaws 36 of one terminal, and in the course of so position-
inq wire 188, the insulation 190 is stripped fro~ the
wire and the conductor core 189 engages the noses 176
in order to obtain reliable electrical contact between
the conductor and the terminal. Shoulders 38a and 38b
by providing compressive support between the side
walls of each terminal and the sides 186 of the passages
180 substantially in alignment with the side walls of
each respective jaw 36, assist in assuring accurate
and rigid positioning of the conductor engaging
edges 176 to assure the desired engagement of the jaws
with the conductor when a conductor is forced against
the jaws.
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From the foregoing detailed description it may be
ascertained that the present invention includes obtaining addi-
tional lengths of metal in and ad~acent to, or between, a jaw
or set of jaws disposed in at least one of the sides of an
electrical terminal. Such additional lengths are produced by
coining the metal used in making the terminal and by limiting
the stretching of the metal to a gradual and dispersed
stretching throughout a substantial portion of the side of the
terminal. It may also be ascertained that the base width
of the jaws is progressively narrowed to provide rigidity
against outward collapse of each jaw under outward pressure
exerted by disposing electrical wires in the terminal. The
shoulders at each side of each jaw insure contact with the
side walls of the receptacle passages very near positions of
alignment with the jaw sides, thus enhancing the compression
strength of the jaws upon the current-carrying wire.
Thus it will be seen that improvements have been
provided in the formation of electrical terminals and
which meet the aforestated objects.
While a particular embodiment of the present
invention has been shown, it will be understood, of course,
that the invention is not limited thereto since modifica-
tions may be made by those skilled in the art, particularly
in light of the foregoing teachings. It is, therefore,
contemplated by the appended claims to cover any such
modifications as incorporate those features which come
within the true spirit and scope of the invention.
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