Note: Descriptions are shown in the official language in which they were submitted.
1298371 F.N. 42901 CAN 5A
~VERMOLDED ELECTRICAL CONTACT FOR THE
MANUFACTURE OF CONNECTORS
Backgr und of the Invention
1. Field of the Invention
This invention relates to a connector formed with
individual contact elements and in one aspect to a connector
for use with electronic cable components with closely spaced
conductors, where the conductors are positioned on 0.63 mm
(0.025 inch) centers, to form a cable termination socket or
header.
2. escription of the Prior Art
Cable terminations for flat cable are well known
and it is typical to connect the individual wires of such a
cable to individual contact elements in an insulative
housing. The contacts typically have an end portion formed
to make electrical contact with the individual wires in the
cable. A cap is then placed onto the housing to maintain
the wires in contact with the contact elements. This
construction is illustrated in U.S.A. Letters Patent Nos.
3,434,093 and 3,444,506 illustrating solderless flat cable
wire connectors. Alternatively, the junction between the
wire of the flat cable and the contact element can be
encapsulated by molding directly over the junctions as
illustrated in U.S.A. Letters Patent Nos. 4,030,799 and
4,094,564.
As the spacing for the wires in the Elat cable
become increasingly smaller, i.e. from 1.27 mm (0.05 inch)
centers for 22 to 24 gauge wire to 1.07 and 0.64 mm (0.0425
and 0.0250 inch) on 28 or 30 gauga solid copper wire it
becomes increasingly difficult to obtain connections and
reduced width elements, and to handle the elements. One
solution was to provide a contact having reduced over-all
width as is illustrated in U.S.A. Letters Patent No.
3,930,708. The elements as disclosed in this
1298371
patent however did not provide as economical a connector as
afforded by the present invention since more material and
more handling was necessary to form the connectors.
The next improvement in the connector for closely
spaced wires in a flat cable is illustrated in U.S.A. Letters
Patent No. 4,009,922. This patent teaches a structure
wherein the insulating body of the connector is formed with
wire support surfaces which undulate to provide a lower wire
support channel associated with one contact element, between
two upper wire support surfaces. This structure affords
contact of alternate wires with contact elements in
alternate rows of contacts and provides sufficient space
between the wires and contacts to avoid cross talk.
The difficulty however with this structure, when
working with flat cable having wire of 30 to 34 gauge, is
that the contact elements become very difficult to handle in
the manufacture of the connectors. The present invention is
directed at a product which provides electrical contacts in a
form which may be readily handled and which afford the
manufacture of substantially any shape or style of connector
to meet the customer requirements. The connector may be a
termination socket or header. The contact of the present
invention affords the manufacture of connectors having two or
more rows of contact elements and for use as a termination
for flat cables of lO to 100 wires with wires or with
contacts closely spaced, e.g., on 0.63 mm to 0.5 mm (0.0250
inch) to (0.02 inch) spacings. The contact of the present
invention is provided with the spring compression reserve
contact elements disposed in rows and joined with the wire
positioning surfaces spaced to afford good electrical contact
and avoid cross talk, voltage breakdown and shorting.
Summary of the Invention
The present invention provides an electrical
contact adapted for insertion into or over-molding into a
connector housing comprising plural electrical contact
elements having opposite ends and contact means at said
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oppos~it.e ends for connection to a conductor and other
electrical component, and an integrally molded polymeric
strip joining the contacts intermediate their ends. The
strip has means for registratlon of the contacts and the
strip with relationship to another strip and/or with a
connector housing.
The electrical contact according to the present
invention is provided with a molded strip which includes
spaced conductor positioning elements positioned along said
strip to position wires of a flat cable in relationship to
the contact elements.
The electrical contact wire positioning elements
are positioned in alternate relationship along the strip with
the contact elements. Actually, there are channels formed in
the strip defining lower wire supporting surfaces aligned
with the wire contacting means of the contact elements and
these channels are positioned between upper wire supporting
surfaces positioned generally between adjacent contact
elements.
An electrical contact according to the present
invention provides a plurality of contact elements which are
disposed in a row, each contact element having opposite ends
with an insulation displacing wire receiving contact at one
end and a strip of polymeric material molded onto the contact
elements intermediate the ends. The strip comprises a
conductor supporting element positioned one on each side of
each said wire receiving contact. The conductor supporting
elements have a support surface which is positioned generally
on a plane with the ends of the wire receiving contacts. The
supporting elements are separated by channels affording
insertion of wires from a flat cable into electrical contact
with the wire receiving contacts.
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Identical rows of the electrical conta~t elements
may be placed together with two rows in face to face
relationship to define an insert for a premolded housin~ or
as a mold insert such that a socket or header for a circuit
board may be provided with the desired shape, length and
style.
Brief Description of the Drawina
The present invention will be more fully described
with reference to the accompanying drawing wherein:
Figure 1 is an isometric view illustrating a band
of contact elements for use in manufacturing a cable
terminating socket connector;
Figure 2 is an isometric view of the band of
contact elements of Figure 1 with a strip of polymeric
material molded thereto;
Figure 3 is an isometric view of a band as shown in
Figure 2 with a carrier strip removed;
Figure 4 is a vertical sectional ~iew of two strips
as shown in Figure 3 placed in face to face position;
Figure 5 is an isometric view of a housing for a
connector;
Figure 6 is a vertical sectional view of the
housing of Figure 5;
Figure 7 is a vertical sectional view of the
housing of Figure 5 with the strips of Figure 4 placed
therein;
Figure 8 is an isometric view of a cap for a
connector housing constructed according to Figures 5 and 6;
Figure 8a is a transverse sectional view of the cap
of Figure 8; and
Figure 9 is an isometric view of a termination
connector and an end of the cable connected thereto with the
same formed of the parts of Figures 3, 5, and 8.
Detailed Description of the Preferred Embodiment
Referring now to the drawing the invention will be
described with respect to its use in the manufacture of
12983'71
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electronic. products requiring the close positioning of
individual electrical contact elements. The contact
elements are initially formed from flat sheets of the
conductive metallic material used ~or such elements, e.g.
beryllium copper. This is usually done by stamping. The
elements of Figure 1 are formed for use in a cable
termination connector and as illustrated comprise a plurality
of contact elements 15 joined together at one end ~y a
carrier strip 16 which is joined to the elements 15 at points
which are easily broken away to remove the carrier strip 16.
The contact elements 15 are each provided a shape or form
characteristic to increase the retention of the element in
the molded on strip to be applied between the contacts of the
elements. As illustrated in Figure 1 the shape or form
characteristic means is an offset portion 20 of the contact
elements 15 formed by two generally 90 bends in the
elements.
As illustrated in Figure 2, the contact elements 15
have been over-molded by a polymeric insulative material to
define an electrical contact 33. The molding of a strip 35
onto the contact elements 15 in the location of the offset
portion 20 affords means for registration of the contact
elements with other contacts and a housing. The strip 35 is
provided with registration means in the form of cooperating
interference fitting projections 36 and recesses 37 spaced
along the length of the strip 35. Tl-e strip 35 is further
provided with shoulders 38 and end members 39 which affo~d
location means for the electrical contacts 33. The strip 35
is further provided with conductor support means for aligning
closely spaced conductors with the contacts or insulation
displacing contact portions 40 of the contact elements 15.
These conductor support means comprise lower wire suppsrting
channels 41 aligned with the contacts 40 to permit a
conductor to be forced into engagement with the U-shaped
contact 40. The channels 41 separate upper wire supporting
~29~3~1
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pillars 42 having troughs formed in the upper surface to
engage and support an insulation coated conductor at a height
above the contacts 40. The troughs form a saddle to position
the conductor along the strip 35. The edges 43 on each
pillar 42 will serve to separate the conductors 64 of a flat
cable 65 as will hereinafter be explained.
Figure 3 illustrates the molded electrical contact
33 with the carrier strip 16 separated from the contact
elements 15 and the alignment strip 35. In this form the
electrical contact is adapted to be placed in opposed
relationship with an identical second electrical contact 44
of the same construction which together with the electrical
contact 33 position two rows of contact elements in opposed
offset relationship. Such a relationship will position the
contact portions 40 in a position where the contacts on one
electrical contact engage alternate wires 64 in a flat ribbon
cable 65 and the contacts of the other electrical contact
engage the other wires. As shown in Figure 4, the opposed
electrical contacts 33 and 44 are aligned by cooperating
projections and recesses 36 and 37 respectively.
When so arranged with two rows of contact elements
the electrical contacts are placed in a connector housing 50
as illustrated in Figure 5. The housing 50 is a premolded
connector housing for a socket connector and has a hollow
central rectangular cavity 51 shaped to receive the pair of
electrical contacts 33 and 44. The housing 50 is provided
with wall means forming chambers 52 having access openings 53
which chambers receive the wiping contact portions 54 of the
contact elements 15. The access openings 53 are adapted to
receive an external electrical contact to make a suitable
connection with the contact element 15. The housing 50 is
further provided with end walls 56 and side walls 57 which
de~ine the cavity 51. The bottom of the cavity 51 is
perforate to provide insertion of the contact portions 54
into the chambers 52 and forms a base 58 upon which rests the
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shoulders 3~ of the strips 35.
The side walls 57 o~ the housing 50 are provided at
their upper surfaces with channels 60 which separate posts
61 having troughs to contact an individual conductor 64 in
the cable 65. The posts 61 on one wall 57 are positioned in
aligned relationship to the pillars 42 of an adjacent
electrical contact. The channels 60 are positioned to be
aligned with an adjacent channel 41 in a strip 35 to afford
location of a conductor with a contact 40. The channels 60
lo on one side wall 57 are aligned transversely with a post 61
on the opposite side of the housing such that the wire
adjacent to a contact 40 is spaced above the adjacent
contacts 40 to restrict interference between signals carried
on one wire with signals carried of the adjacent wire.
As illustrated in Figure 7, the assembled connector
housing 50 and electrical contacts 33 and 44 are prepared to
accept the ribbon cable 65. In this example the wires in the
ribbon cable are positioned on 0.635 mm (0.025 inch) centers
which provides a very close spacing for the contacts in the
electrical contacts 33 and 44. A cap 66 or a tool face (not
shown) is used to separate conductors 64 in the cable and
force the conductor wires of the ribbon cable 65 into
contacting engagement with the insulation displacing contact
portions 40 of the contact elements 15. The cap 66 and or
tool has a surface to mate with the posts 61 of housing 50
and the pillars 42 of the electrical contacts 33 and 44,
affording means for separating the individual conductors in
the cable and positioning the alternating wires in the
channels and adjacent wires on the posts of one side and in
the channels of the other side, as illustrated in Figure 9.
The cap 66, see Figure 8a is provided also with spaced
conductor support surfaces 60a separated by channels 61a and
support surfaces 41a separated by channels 42a. The surfaces
60a and 41a are formed with arcuate troughs like the pillars
42 and posts 61. The edges of these surfaces 60a and 41a
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coo~erate with khe edges on the posts 61 and pillars 42 to
shear the cable insulation between the conductors 64 to drive
the conductors into the contact portions 40. The cap 66 has
suitable locking means to lock the cap in place on the
housing 50 after being positioned to afford the wire
connections of the cable 65 to the contact elements. The
locking means illustrated comprises resilient U-shaped pawls
67 at the ends of the caps. The bight portion of the pawls
67 are received over detents 68 to fit beneath the detents
and hold the cap in place.
Having described the invention with reference to
one embodiment of an electrical connector as illustrated in
the drawings and the alternatives referred to hereinabove, it
is to be understood that other changes can be made without
departing from the scope of the invention as defined in the
appended claims.
