Note: Descriptions are shown in the official language in which they were submitted.
-` 1175519
AN INSERT FOR AN ELECTRICAL
CONNECTOR HAVING REMOVABLE CONTACTS
This invention relates to electrical connectors and
more particularly to an insert within the connector that
retains electrical contacts.
Electrical connectors generally include a plug and
receptable, each of which has an insert of dielectric
material provided with multiple passages within which
electrical contacts are retained. The insert is mounted
within a metal shell of the connector. ~ome connectors
provide for rearward insertion and front or rear release
of the electrical contact for removal. Other types of
connectors provide for front insertion and front or rear
release of electrical contacts. These features are
desirable and facilitate the assembly and servicing of
the connectors. ~n example of a one piece molded insert
for retaining contacts within a connector may be found in
U.S. Patent 4,157,806 issued June 12, 1979 and entitled
"Apparatus for Making Electrical Connector Insert." In
the foregoing types of connectors, the electrical con-
tacts in the connector have a mating end and a wire
receiving end. Wires are attached to the wire receiving
end of the contact by one of three methods, i.e.,
soldering, crimping or wrapping the wire around the rear
end of the contact. To wrap the wire around the contact,
wire wrapping tools are used to rotate a wire around the
contact. The wire wrapping tool is similar to a drill in
that a wire, attached to the forward portion of the tool,
is placed against a contact so that when the tool
rotates, the wire is wrapped around the contact. Unfort-
unately, in a connector having an insert of the type
shown in 4,157,806 patent, the contact rotates when a
wire is wrapped around the contact. This prevents the
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wire from wrapping tightly around the contact which results
in a poor electrical connection. One example of a means for
preventing rotation of a contact in a connector is the
addition of a separate locking plate mounted to the rear of
the connector. The plate includes a plurality of apertures
each having a configuration that keys to the configuration of
a contact to prevent rotation of the contact. Accordingly,
rotation of a contact during the process of attaching a wire
to the contact by wrapping the wire around one end por~ion of
the contact has been a problem to which practical and
economical solutions are being sought.
Disclosure of-the Invention
This invention provides an electrical connector insert
for a connector that will prevent a contact from rotating
once it is mounted within the connector insert. The invention
is characterized by an electrical connector insert that
includes a passage therein having a square shaped passage
adapted to receive the wire receiving end of an electrical
contact having the same configuration. The matching shapes
of the passage and contact prevents rotation of the contact.
Accordingly, it is an advantage of this invention to
provide an electrical connector insert that will prevent
rotation of a contact once the contact is mounted in the
connector i~;ert and hence, facilitate the wrappins of a wire
around one end portion of the contact.
Another advantage of this invention is improved
electrical contact between a wire wrapped around a contact
and the contact.
Specifically, the invention is used in combination
with an electrical connector insert for receiving and retaining
a plurality of elongated electrical contacts, each contact
having a forward mating portion, a rear wire receiving portion
having at least one flat surface thereon and an enlarged medial
section having a forwardly facing shoulder and a rearwardly
facing shoulder, the insert being of the type having: a single
piece unitary body of molded dielectric material having a
plurality of passages therethrough from a front face to a
rear face, each passage adapted to receive a respective
electrical contact therein which is insertable from the front
mg/ ~ 2 -
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face of the body, each passage dimensioned so that a portion
of the rear wire receiving end of the contact extends out of
the rear face of the body; a plurality of ribs integral at
one radial end with a wall of each of the passages, each of
the ribs terminating in one axial direction in a forwardly
facing shoulder adapted to engage one of the contact shoulders
when a contact is inserted into the body from the front face;
and a plurality of contact retention fingers integral with the
body and located within each of the passages, each of the
fingers extending rearwardly inwardly from the wall of the
passage to a forward free end which terminates a predetermined
distance from the rib shoulders, the free end adapted to
engage the other of the contact shoulders when the contact is
inserted into the body from the front face, the fingers being
resiliently deflectable radially to permit the enlarged
section of a contact to pass the free ends thereof upon
insertion of the contact into the passage from the front face,
the fingers returning to their original position behind the
other of the contact shoulders to limit forward movement of the
contact in the passage, the fingers being substantially rigid
in one axial direction when in their original position so as
to provide a positive stop against forward movement of an
electrical contact. The invention relates to the improvement
comprising: an annular ring in each of the passages, the ring
integral with the other radial end of the ribs and having a
central bore having a configuration that includes at least one
flat surface and is adapted to receive a similarly shaped
rear wire receiving end of a contact inserted into a passage
whereby, when a contact is inserted into the passage from the
front face of the body, the enlarged medial section of the
contact is captivated between the free ends of the fingers and
the shoulders of the ribs and the rear wire receiving portion
of the contact extends through the bore in the annular ring
and beyond the rear face of the body whereby the contact is
prevented from rotating when a wire is wrapped around the wire
receiving end of the contact.
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1175519
Detailed Description of the Invention
FIGURF 1 is a partial diagramatic view of an
electrical connector insert incorporating the principles
of this invention.
FIGURE 2 is a partial end view of the insert shown
in FIGURE 1.
FIGURE 3 is a partial cross sectional side view of
an alternate embodiment of the invention.
FIGURE 4 is a cross sectional view of the insert
shown in FIGURE 3 taken along the lines IV-IV.
FIGURE 5 is a cross sectional view of the insert
shown in FIGURE 3 taken along the lines V-V.
FIGURE 6 is a cross sectional view of the insert
shown in FIGURE 3 taken along lines VI-VI.
FIGURE 7 illustrates a portion of an electrical
connector assembly incorporating the principles of this
invention.
Referring now to the drawings, FIGURE 1 illustrates
an electrical connector insert 10 embodying the princi-
ples of this invention. The insert 10 is generally
comprised of a dielectrical material and includes a
plurality of passages 11 (only one shown) each containing
therein a plurality of contact retaining fingers 15 and a
plurality of contact retaining ribs 12. Each of the
contact retaining fingers 15 is resiliently and radially
expandable outwardly and terminates in a free end 16. In
this embodiment, there are four contact fingers 15 and
ribs 12, although more or less may be used. The free
ends 16 of each contact retaining finger 15 in each
passage 11 form an annular shoulder facing towards one
end of the passage 11. Each rib 12 has one radial end
integrally connected to the wall of the passage 11 in the
insert body 10. Integrally connected to the other radial
end of each of the ribs 12 is an annular ring 13 that
~175519
includes a central bore 14 having a square shaped
passage. Alternately, the passage 14 may take many
shapes so long as it includes at least one flat surface
and is configured or keyed to match the shape of the wire
receiving end of a contact. Each o~ the ribs 12
teeminate at one axial end in an internal shoulder 17
that faces the free ends ]6 of the contact retaining
fingers 15. To illustrate the features of the fingers 15
and ribs 12 they have been separated further apart.
FIGURES 3 and 7 show that the ends 16 of the fingers ]5
and the shoulders 17 of the ribs are spaced closely so 3S
to closely captivate the enlarged portion oE a c-~n~a~t.
FIGURE 2 is a portion of the rear face 19 of the
insert 10 and illustrates the symmetric~l arrangement o~
the ribs 12 integrally connected together by the annular
ring 13.
FIGURE 3 is a cross sectional view of a passage in
an alternate embodiment of the insert 10 which includes
only three ribs 12 and three fingers l~. ~he contact
r~taining fingers 15 are resiliently and radially
deflectable outwardly to allow the enlarged portion of a
contact (not shown) to pass by the free ends 16 of the
fingers 15 which then snap into place behind the enlarged
portion of the contact. The enlarged portion of the
contact is then captivated between the free end 16 of the
deflectable Eingers 15 and the shoulders 17 of the ribs
12. The fingers 15 being substantially rigid in one
- axial direction.
FIGURE 4 is a cross sectional view taken along the
lines IV - IV of FI5URE 3 and illustrates the syn~etrica'
arrang-ment of the three ribs 12 in the rear portion of
the insert 10 and the location of the square shaped bore
14 in the annular ring 13 connecting one radial end of
each of the ribs 12 together.
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FIGURE 5 is a cross sectional view taken along the
lines V - V of FIGURE 3 and illustrates the three
resiliently and radially deflectable fingers 15 which are
arranged in a shape of a truncate3 cone.
FIGURE 6 is a cross sectional view taken along the
lines VI - VI of FIGURE 3 and illustrates the configura-
tion of the passage 11 in the forward portion of the
insert 10.
FIGURE 7 illustrat~s the portion of an electrical
connector having a contact retaining insert 10 that
incorporates the principals of this invention. The upper
portion of the connector illustrates how a conta~r ?0 is
mounted in the contact retaining insert by captivation of
the enlarged portion 35 of the contact between the free
end 16 of the fingers 15 and the shoulders at one end of
the ribs 12. The lower portion of the connector illus-
trates how a contact retaining tool 20 is inserted into
the passage 11 through the forward face 18 of the insert
10 to deflect the contact retaining fingers 15 thereby
disengaging the free ends 16 thereof from the forwardly
facing shoulder 36 of the contact 30 to release the
contact 30 for removal from the forward end of the insert
10.
The contact 30 includes a forward mating portion 31
and a rear wire receiving portion 32 having a configura-
tion the same as that of passage 14 ( FIGURE 4), except
slightly smaller. A portion of the rear wire receiving
end 32 of the contact 30 extends beyond the rear face 19
of the insert 10 to permit the wrapping of a wire 40
around the rear wire receiving end 32 of the contact 30.
While a preferred embodiment of the invention has
been disclosed, it will be apparent to those skilled in
the art that the advantage of this invention may still be
obtained even though minor changes are made to the inven-
tion set forth in the appended claims or that certain
~175519
--6--
features of the invention may be used without corres-
ponding use of other features. For instance, the
configuration oE the bore 14 in the insert 10 may be
rectangularly shaped or have any configuration that
includes at least one flat surface and which ~.atches the
configuration of the rear wire receiving portion of a
contact inserted into the bore (14) so that the
en~agement between the flat surface on the contact and
the passage prevents rotation of the contact.
~ccordingly, it is intended that the illustrative and
descriptive materials herein be used to illustrate the
principles of the invention and not to limit the scope
thereof.
