Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to an electrical contact member,
and particularly to a female electrical contact member for mating
with a male contact pin.
In United States Patent Specification No. 3,915,537
there is described a female electrical contact member comprising
a substantially U-shaped body portion from the sides of which
extend a pair of opposed resilient cantilever contact arms between
which a male contact pin can be received.
With this known contact member the contact arms are nor-
mally spaced from each other and are urged apart on insertion ofa male contact pin between them. The contact force acting be-
tween the contact arms and the male contact pin is thus derived
solely from the deflection of the contact arms caused by the male
contact pin, and is therefore relatively low. The contact force
could be increased by reducing the initial spacing between the
contact arms such that a greater deflection thereof is obtained
on insertion of the male contact pin. However, such a measure
introduces the disadvantage that the force necessary to insert
the male contact pin is considerably increased, this being a par-
ticular disadvantage when a plurality of the contact members areused in a connector where simultaneous mating of all of the con-
tact members with associated male contact pins is necessary.
According to this invention there is provided a stamped
and formed sheet metal contact member of the type comprising a
U-shaped body portion having a bight and sides extending from the
bight, a pair of opposed contact arms which extend from the sides
and substantially parallel to the bight, the contact arms having
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free ends which are spaced from the one end of the bight, the
contact member being characterized in that: a support arm extends
from the one end of the bight beside the contact arms, the sup-
port arm having a free end which is between the end of the bight
and the free ends of the contact arms, the contact arms being
resiliently biased towards each other, the free end of the con-
tact arm extending laterally between the contact arms and main-
taining free ends of the contact arms in spaced-apart relation-
ship with the contact arms bearing against, and being resiliently
biased against, the free end of the support arm.
The contact member of this invention has the advantages
that it provides a relatively high contact force on a male con-
tact pin mated therewith while still allowing relatively easy
insertion of the male contact pin.
More particularly, the contact arms can initially be
bent to be in contact with each other, that is to a position which,
if they were to be left in such position, would make insertion
of a male contact pin very difficult, the support arm then being
located between the contact arms to hold them apart at a dis-
tance making insertion of the male contact pin relatively easy.The contact arms are then resiliently biassed against the sup-
port arm but when a male contact pin is inserted they are further
deflected apart and out of contact with the support arm, the
contact force with which the contact arms then grip the male
contact pin deriving not only from the further deflection of the
contact arms occurring on insertion of the male contact pin but
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also from the force with which the contact arms were resiliently
biassed against the support arm.
The invention will now be described by way of example
with reference to the accompanying drawings, in which~
Figure 1 is a plan view of a first female contact mem-
ber according to the invention prior to a support arm being
positioned between the contact arms;
Figure 2 is a side view of the contact member of Figure
1;-
Figure 3 is a view similar to Figure 1 but with the
support arm moved to its final position;
Figure 4 is a side view of the contact member of Figure3;
Figure 5 is a view similar to Figure 4 but showing a
male contact pin mated with the first contact member;
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Figure 6 is a plan view of a second contact member in an only partly
formed condition;
Figure 7 is a side view of the contact member as seen in Figure 6;
Figure 8 is a view similar to Figure 6 but with the contact member
in its final form;
Figure 9 is a side view of the contact member of Figure 8; and
Figure 10 is a view similar to Figure 9 but showing a male contact
pin mated with the second contact member.
The contact member showm in Figures 1 to 5 is stamped and formed
from sheet metal integrally joined to a plurality of similar contact members
in strip form, by means of carrier strips 100, in knowm manner.
The contact member comprises a contact portion 1 and a wire connec-
tion portion 2 which is of kno~m insulation displacement form and which will
not therefore be described in detail.
; The contact portion 1 comprises a substantially U-shaped body
portion 3 from the sides of which extend a pair of opposed resilient canti-
lever contact arms 4 and 5 each indented near its free end to provide a
contact project1on 6 directed towards that of the other contact arm.
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Each contact arm 4 or 5 is formed with a longitudinally
extending, inwardl.y directed indentation 7 which serves to
stiffen the contact arm across its junction with the body
portion 3. Extending from the bight of the body portion 3
is a third, support arm 8 which projects in the same
direction as the contact arms 4 and 5, the ~ree end of the
support arm 8 being curved towa:rds the contact arms 4 and
5.
As shown in Figures 1 and 2, during manufacture of
the contact member the stamped blank from which the contact
member is formed is initially formed such that the contact
projections 6 on the contact arms 4 and 5 are in contact
With each other (Fi~ure 2), the support arm 8 not being
positioned between the contact arms 4 and 5 (Figure 1).
The contact arms 4 and 5 are then urged apart and
the support arm 8 then moved to be positioned between them
(Figures 3 and 4). The contact arms 4 and 5 resiliently
engage the support arm 8 which then serves to hold their
contact projections 6 apart (Figure 4). The contact member
is then ready for use.
As shown in Figure 5, the support arm 8 holds the
contact projections 6 spa~ed by a distance less than the
relevant dimension of a male contact pin 200 to be mated
with the contact member, such that on insertion of the pin
200 between the contact projections 6 the contact arms 4
and 5 are urged out of engagement with the support arm 8
and remain th~ls while the pin 200 is mated with the contact
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member.
Thus, insertion of the pin 200 between the contact
arms 4 and 5 is relatively easy due to the initial spacing
between the contact projections 6, while the contact force
with which the contact arms 4 and 5 finally grip the pin
200 is relatively high, since the force results not only
from the deflection of the contact arms 4 and 5 caused by
insertion of the pin 200 but also from the fo~ce with which
the contact arms 4 and 5 initially grip the support arm 8.
Referring now to Figures 6 to 10, the second contact
member here shown is somewhat similar to that shown in
Figures 1 to 5 and corresponding parts have the same
references.
The principle difference is that in the contact
lS member of Figures 6 to 10 there is no support arm 8 but
merely a bight portion 18 between the contact arms 4 and 5.
During manufacture of the second contact member the
: stamped blank from which the contact member is formed is
; initially formed such that the contact arms 4 and 5 each
extend at a certain angle to the plane of the bight 18 and
side walls of the body portion 3, this certain angle being
such that when the U-shaped body portion 3 is subsequently
formed the contact arms 4 and 5 become inherently
resiliently biassed against each other at a position 10
between their roots 9 and their free ends 6 as shown in
Figure 9, the contact arms 4 and 5 being shaped such that
their contact projections 6 are then spaced apart for
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insertion of a male contact pin (200 in Figure 10) there-
between. The contact arms 4 and 5 then each extend at an
angle which is less than the initial certain angle to the
plane of the associated side wall of the body portion 3.
The contact member is then ready for use.
As shown in Figure 10, the contact projections 6 are
initially spaced by a distance less than the relevant
dimension of a male contact pin 200 to be mated with the
contact member, such that on insertion of the pin 200
between the contact projections 6, the contact arms 4 and 5
are urged out of engagement with each other and remain thus
while the pin 200 is mated with the contact member.
Thus, insertion of the pin 200 between the contact
arms 4 and 5 is relatively easy due to the initial spacing
between the contact projections 6, while the contact force
; with which the contact arms 4 and 5 finally grip the pin
200 is relatively high, since the force results not only
from the deflection of the contact arms 4 and 5 caused by
~ insertion of t:he pin 200 but also from the force with which
the contact arms 4 and 5 are initially biassed against each
other.
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