Note: Descriptions are shown in the official language in which they were submitted.
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MINIATURE ELECTRICAL TERMI~L
F~R L~W ENEP~;Y EI.2CTRON~ CIRCUITS
The present inYention is directed to the field of
electrical connectors and more specifically to the area of
male and female electrical connector configurations
ide~lly ~uit~d for low energy electronic circuit3~
MicroscQpic evaluation of pcior art electrical
connector tenminal des~ na, whlch have undergone environ-
~nental steess such as thermal expansion and contraction a~
well a~ mechanical vibrations, have dis¢losed ~ear track~
and metallic re~idue resulting from the physical move~ent
of one electrical contact on another~ The electrical
effect of this movement is seen as a resi3tance ~ncrea~e
through the contact interface as a re~ t of ino ~anlc
insulating films and residue which have been eroded from
the metallic surface~ of the contacts~ In low ener~y
electronics, such as employed in microcircuit devices
which ~enerate low current signals, such resistanca
changes are unacceptable because they cause erroneous
information to be communicated~
The present in~ention is intended to o~ercome the
problems found in pr ior art terminals by providing an
electrical connector which has a p~olonged stable life
with a constant low interface resistance~ The present
invention provides an electrical connector in ~hich the
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contact geometry and mechanical force loading are such that
physlcal movement between the mated male and female members
is substantially reduced or eliminated.
The described embodiment utilizes a cylindrical pin
5 type male connector that mates with a cylindrically shaped
female connector. The female connector consists of a hollow
body element and an outer cylindrical hood that is mounted
concentricaLly around the body element. The body element has
a first open end portion for receiving the male pin connector
10 through an aperture in the end of the hood and a second
support portion connected to the first end portion. The
cylindrical hood has a first apertured end aligned with the
open end portion of the body. The first end portion of the
body element is formed as a pair of "V" shaped contacts
15 having respective apexes immediately adjacent the inner
surface o the cylindrical hood and having opposing surfaces
b~irlg generally planar and tangential to the male pin con-
nector when inserted. The normal distance between the oppo-
sing surfaces of the pair of "V" shaped contacts is less than
20 the cross sectional diameter of the male pin connector. As
such, the "V" pairs are spread apart by the insertion of the
male pin connector, until the apex of each "V" pair contacts
the inner surface of the hood. This causes each of the four
planar surfaces of the "V" shaped contacts to be compressed
25 in intimate contact with the outer surface of the male pin
connector along a separately defined line of contact that is
substantially parallel to the axis of the connector.
A housing for a cylindrical electrical connector is
also described in which an insulating block provides a lock-
30 ing mechanism to hold the female cylindrical connector in afixed position by utilizing a resilient locking arm adjacent
the chamber containing the female connector. In addition,
the housing contains an accessible recess in which a remov-
able locking wedge is inserted to prevent the resilient arm
35 from being moved away from its locking position with respect
to the female connector inserted in the chamber of the
housing.
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The inventionis described further, by way of
illustration, with reference to the accompanying drawings,
in which:
Fig. 1 is an exploded view of the matable
components of the present invention;
Fig. 2A is an isometric partial cross-section of
the fe~ale connector assembly of the present invention;
Fig. 2B is a cross-section of the female
connector assembly taken along lines 2a 2B shown in Fig.
2A;
Fig. 2C is an elevational cross section of the
emale electrical connector ~hown in Fig. 2A;
Fig. 3A is an isometric partial cross-section of
the mated male and female connector portion~ of the
lS present invention;
Pig. 3B is a cro~s-section o~ the assembly taken
~long the lines 3B-3B shown in Fig~ 3A;
Fig. 3C ls an elevational cross-section o~ the
present invention shown in Fig. 3A;
~ig. 4 is an isometric partial cross-section of a
housing for the femala electrical connector of the presen~
invention;
Fig. 5 is a partial cross-section of the housing
illustrated in Fig. 4 asse~bled with a locking wedge;
Fig. 6 is a partial cross-section illustrating
the housing containing the female electrical connector in
a locked configuration.
Fig. 7 is a comparison plot of resistance
measurements taken during a num~er of temperature cycle
3v Referring to the drawings, an exploded view of
the present invention is shown in Fig. l in which a
cylindrical male pin connector 4 is illustrated in an
exploded view along with a female connector 20. The
male pin connector 4 includes an elongated contact
portion 10 that is generally cylindrical in shape with a
tapered nose portion 12. An enlarged stop 14 definesthe
insertion length of the cylinder 10. On the opposite
side of the stop 14, a depressed area 16 is provided for
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locking the pin in an insulated housing, such as that shown
in Fig.4. The male pin connector 4 is soldered or crimped to
an electrical conductor in a conventional manner at its wire
end 18.
The female connector 20 includes a main body ele-
ment 22 formed as a hollow, generally cylindrical unit and a
hood element 50. The body element 22 includes a first end
portion 29 for accepting and making electrical contact with
the cylindrical portion 10 of the male pin connector 4. The
body element 22 also contains a second portion 21 which has
an inner diameter measurement greater than that diameter of
the cylinder 10 to provide clearance and to provide struc-
tural support for the first end portion 29. The first end
portion 29 of the body element 22 is formed as a pair of
15 opposing "V" shaped contacts 23 and 24 that are resiliently
sprung and individually connected to the second body portion
21 vla integral biasing hin~es 34 and 36 formed by cutou-ts 33
and ~0. The opposing "V" shaped con-tacts 23 and 24 are
formed to have generally planar inner surfaces 27 and 28
20 joined a~ an apex 25, and generally planar inner surfaces 30
and 32 joined at an apex 26. To the rear of the body element
22, a depressed area 44 is formed to provide a seat for a
locking member in an insulative connector, such as that shown
in Fig. 4. The female conector 20 is connected to an elec-
25 trical conductor at its terminal end 46 via solder or acrimping tab 48.
The hood 50, shown in Fig. 1, is assembled to the
female connector body 22 as shown in ~ig. 2A by a conven-
tional crimping technique as indicated by numeral 54 in Fig.
30 2C. The inner surface 51 of the hood 50 is adjacent the
apexes 25 and 26, of the opposing "V" shaped contacts, and
provides a limit to the outward movement of those apexes when
the male pin connector 4 is inserted therein.
Figure 2B is a cross-section of the assembly shown
35 in Fig. 2A taken along section lines 2B-2B. In this figure,
a dimension ~1 is shown as the minimum relaxed distance
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between opposing planar surfaces of the "V" shaped contacts
23 and 24. The contacts 23 and 24 are formed so that the
dimension Dl is less than the outer diameter D2 of the cylin-
der 10 on the male pin connector 4. On the other hand, the
inner diameter of the second portion 21 of the body element
22 is greater than D2, to allow for clearance of the inserted
cylinder 10, of the male pin connector 4.
Fig. 2C is an elevational cross-section of the
assembly shown in Fig. 2A and serves to illustrate the taper-
ed arrangement of the "V" shaped contacts 23 and 24 as theyextend from the second portion 21 of the connector body 22
through hinge elements 34 and 36, respectively. The aperture
52 is also shown as having a diameter D3 which is greater
than D2 and Dl. The aperture 52 is, of course, coaxially
positioned with respect to the body element 22 in order to
center the pin connector 4 and prevent collision with the
edges of contacts 23 and 24 when the nose end 12 of the male
pin connector 4 is inserted therein.
Figs. 3A, 3B and 3C illustrate the assembly, where-
by the male pin connector 4 i.s fully mated with the femaleconnector 20. Upon initial insertion into the aperture 52 of
the hood 50, -the nose end 12 of the pin connector 4 is in
contact with the inner surfaces 27, 28, 30 and 32. The "V"
shaped contacts 23 and 24 yield in the path of least resis-
tance offered by biasing hinges 34 and 36 until the apexes 25and 26 abut the inner surface 51. Meanwhile, the surfaces
27, 28, 30 and 32 are caused to be spread apart and thereby
increasing the included angle at the apex and also provide
compressive tangential
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contact to the outer sur~ace of the cylinder 10 of the
male pin connector 4. This tangential contact is defined
as separate lines of contact Ll, L2, I.3 and L4 which run
the length of the "V" shaped contacts 23 and 24. In this
manner, the cylinder portion 10 of the pin connector 4 is
held in compressive suspension and the contact points are
substantially permanent throughout the life of the
connection, even though subjected to vibrational and
thenmal forces.
Tests were performed by meas~ ing resistance
values of a conventional connector and those of the
present invention subjected to a series of high and low
temperature cycles in order to evaluate and compare their
relative performances. Fig. 7 illustrates the res~ ts of
those cyclical temperature tests wherein the conventional
connector resistance values ~taken at 100 a) are plotted
a~ X, and the present invention resistance values are
plotted as Y. It is readily apparent that the present
invention offers improved stability and long life over
convention~ connectors due to it~ unique config~ration.
An insulative housing 80 is shown in Fig. 4 which
is utilized to supp~rt an array of female electrical
conductors~ such as de~ribed above, in a positively
locked configuration having their open ends electrically
insulated from the external surface of the housi~ . The
insulative housi~ 80 is formed to have an elo~ated
chamber 82 which a diameter which is adequate to receive
female connector 20 in an open end 86. At the opposite
end of the chamber 82, an apertured stop 84 is defined
that is approximately the same diameter as the aperture 52
on the hood 50. The size of the aperture 84 is designed
to accept the insertion of the pin connector cylinder 10
and orients the nose end 12 60 as to be coaxial hith the
female connector 20. A resilient locking arm 88 is fonmed
as an exten6ion of the in~ulative housing 80 and contains
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a locking tab 90 which protrudes into the chamber 82, so
as to bear against the female connector as it is inserted
into the chamber 82 and ~o hold tha~ connector in place
when it is fully inserted~ A recess 89 is formed within
the insulative hcusing 80 so as to be adjacent the
resilien~ locking anm 88. The recess 89 is accessible to
receive a locking wedge 100 that is formed to fit in the
recess 89 so as to restr ict any movement of the locking
arm 8~ from its protruding position as shown in Fig~ 4~
The locking wedge 100 contains a receding sur~ace 102
which abuts against a lower surface 92 of the resilient
locking arm 88 and prevents any downward movement of the
tab 90 once the locking wedge is in~erted. A chamber
portion 104 of the locking wedge 100 provides a bottom
element for the chamber 82 when the locking wedge 100 is
installed and an extending portion 106 provides a sector~d
completion for the apertured stop 84~ A key 94 and a
ke~way 108 are ~so provided on the respective insulative
housing 80 and the locking wedge 100 to provide alignment
2~ guidance upon insertion~
Fig~ 5 illustrates the insulative housi~ 80 with
the locking wedge 100 inserted in the recess 89~ Fig~ 6
illustrates the complete assembly of the ~emale electrical
connector 20 installed within the insulative housing 80
and locked in position by the tab 90 positioned in the
depression 44 and the locking wedge 100 inserted in the
recess 88~ Of course, during inst~ lation, the locking
wedge 100 is removed prior to insertion of the female
connector 20 through the end 86 of the chamber 82~ As the
female connector 20 is inserted, the forward end of the
hood 50 contacts the ramped surface 91 of the resilient
locking arm 88 and causes the arm to deflect in a downward
manner until the depression ~4 is over the locking tab 90.
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At that point, the resilient locking tab 90 will return to
its normal position and retain the female connector 20
within the chamber 82. The func~ion o:E the then inserted
locking wedge 100 is to insure and strengthen the locking
function of the tab 90 as it bears against the connector
20.
It will be apparent that many modifications and
variations may be implemented without departing from the
8cope of the novel concept oE this invention. Therefore,
it is intended by the appended claims to cover all such
modifications and variations which fall within the true
spirit and scope of the invention.
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