[0001] This invention relates to an electrical connector for the interconnection of individual
conductors of an electrical cable to a printed circuit board.
[0002] Electrical connectors exist in the electronics industry having the capability of
interconnecting individual conductors of a multi-conductor flat cable to circuit traces
of printed circuit boards. These connectors are mounted to the board having electrical
terminals exposed at a lower edge thereof which make electrical contact with the traces
on the printed circuit board. The electrical connectors also have electrical terminals
which accept the conductors in an electrically conducting manner.
[0003] One electrical connector in particular, includes an electrical terminal housing having
through passageways for electrical terminals. The housing has a lower face which mounts
proximate to the printed circuit board and an upper face which accepts the multi-conductor
cable. The terminals are placed in respective passageways within the connector housing,
with printed circuit board posts extending beyond the lower face, and cable receiving
portions of the terminals disposed proximate to the upper face. The housing also includes
a camming member which is moveable to open the cable receiving portion of the terminal,
to accept the wire in a zero insertion force fashion. Release of the camming member
returns the spring to an undeflected position and into contact with the wire.
[0004] A disadvantage of the above mentioned connector is that the upper face, which includes
the conductor receiving openings, is an integral part of the moveable camming member.
Thus, to make the electrical connection, the cable is stripped to expose the conductors,
and the cam is actuated to open the conductor receiving portions of the terminals.
The actuation of the camming member also moves the upper face and the conductor receiving
openings, as the conductor receiving openings are integral with the camming member.
When the conductors are inserted within the openings, and the camming member released,
the spring force actually forces the camming member, including the upper face and
openings, upwardly which drives the cable and conductors upwardly also. This reverse
spring force could take the conductors out of contact with the terminals when the
upper face is moved.
[0005] In the present invention, the electrical connector is characterized in that the upper
face of the housing has a plurality of conductor receiving openings therein, the upper
face of the housing and the openings being fixedly rigid relative to the camming member.
The camming member is moveable relative to the housing and the upper face, whereby,
when the camming member is moved to actuate and release the conductor receiving portions
of the terminals, the upper face remains fixed relative to the camming member.
[0006] A further object of the instant invention is to design an electrical connector which
can accomodate a range of wire sizes.
[0007] The further object has been accomplished by designing an electrical connector of
the type for interconnecting a plurality of electrical conductors to further conductive
elements. The connector has an insulating housing retaining a plurality of electrical
terminals with terminal passageways of the housing, the connector housing having conductor
receiving openings therein which are in alignment with conductor receiving sections
of the terminals. The connector is characterized in that the conductor receiving openings
comprise axially extending passageways comprising arcuate sections contiguous with
further surfaces which extend inwardly of the radius of curvature of the arcuate sections,
whereby the conductors are aligned towards the center of the passageway by the further
surfaces.
[0008] The preferred embodiment of the electrical connector will now be described with relation
to the drawings, where:
Figure 1 is a front plan view of the connector of the subject invention;
Figure 2 is a top plan view of the connector shown in Figure 1;
Figure 3 is a cross-sectional view through lines 3-3 of Figure 2;
Figure 4 is a side plan view of the electrical terminal shown in Figure 3;
Figure 5 is similar to the cross-sectional view of Figure 3, absent the electrical
terminal;
Figure 6 is an end view of the electrical connector;
Figure 7 is a cross-sectional view through lines 7-7 of Figure 3 showing a large diameter
wire terminated; and
Figure 8 is a cross-sectional view similar to that of Figure 6 showing an optional
smaller diameter wire terminated to the same electrical connector.
Figure 9 is a cross-sectional view showing an alternate embodiment of the present
invention.
[0009] With reference first to Figure 1, the electrical connector of the instant invention
is designed for applications where the electrical connector is mounted to through
holes in a printed circuit board for electrical connection with a plurality of circuit
traces on a printed circuit board. The electrical connector provides easy installation
of a multi-conductor flat cable by stripping an end of the insulation which covers
the conductors of the cable, and the stripped ends of the cable can be inserted into
the wire receiving openings of the electrical connector.
[0010] The subject connector shown generally as 2 in Figure 1 includes an insulating housing
4 having side walls 6 and 8 (Figure 3) and end walls 10 and 12. The electrical connector
2 further comprises an actuator 50 (Figure 2) which is moveable in a downward direction
to open the electrical contacts for insertion of the cable conductors. The electrical
connector 2 further includes a plurality of electrical terminals 70 (Figure 3) having
portions which extend below the lower surface 34 of connector for interconnection
with printed circuit boards.
[0011] With reference first to Figure 5, the housing 4 will be described in greater detail.
Figure 5 is a cross-sectional view through lines 3-3 of Figure 2 excluding the electrical
terminal 70. The housing 4 includes a plurality of wire receiving openings 20 which
extend from the upper wire receiving face 16 and extend into the terminal receiving
cavities 24. Also shown in Figure 5 is the fact that the conductor receiving opening
20 merges with a conductor aligning channel 22.
[0012] With reference now to Figure 7, the detail of the terminal receiving cavity 24 and
the wire aligning channel 22 are described in greater detail, remembering that Figure
7 is a cross-sectional view through lines 7-7 of Figure 3. The terminal receiving
channel is defined generally by opposed surfaces 24a and 24b while the wire receiving
passage is defined by arcs 22b and planar surfaces 22a. It should be noted that the
planar surfaces 22a are inside of the radius of curvature which is formed by the arcuate
surfaces 22b.
[0013] With reference now to Figure 4, the electrical terminal includes a horizontal base
section 72 which is continuous with a vertical base section 74. Extending from the
vertical base portion 74 is a first leg 76 which forms an upper contact portion 78.
The leg portion 76 is continuous, through a bight section 77, with a second leg section
80 which extends upwardly to form an opposed and second contact portion 82. Extending
from the second leg portion 80 is a lever section 84. Extending from the horizontal
base section 72 is a printed circuit board post 86.
[0014] Finally, with reference to Figures 5 and 6, the actuator includes a horizontal section
52 and arm sections 62 which extend downwardly from the horizontal section 52. An
aperture 58 extends from the upper surface 52 of the actuator and extends downwardly
to form a stop surface 64 (Figure 6). With reference to Figure 1, the housing end
surfaces 10 and 12 each include a recessed section 36 having a downwardly facing latch
38 along a vertical centerline of the recessed section 36. The latches 64 and 38 cooperate
to form an upper stop position of the actuator member 50. The lower surface 54 of
the actuator in combination with the upper edge 32 of the housing (Figure 5) provide
a maximum deflection for the contacts which prevents overstressing the contacts.
[0015] To assemble the connector of the instant invention, the plurality of terminals are
positioned within the housing 4 being inserted through the terminal receiving cavities
24 from the lower surface to the connector housing. The actuator 50 can then be assembled
to the connector housing with the arms 62 being inserted into the recesses 36 on each
end wall 10 and 12 until the stop surface 64 rides up over the latch to abut the downwardly
facing shoulder of the ramp 38. It should be noted that when in this position, the
cam surface 56 (Figure 5) is proximate to the lever portion 84 (Figure 3) such that
downward movement of the actuator 50 causes an outward deflection of the lever portion
84 on the cam surface 56, thereby spreading the opposed contact portions 78 and 82
for insertion of the stripped conductors.
[0016] It should be noted that the actuator 50 moves relative to the housing and relative
to the wire receiving openings 20. Said differently, the wire receiving openings are
not integrated with the actuator such that the wire receiving openings move upwardly
and downwardly with the actuator. In some prior art connectors, the wire receiving
openings are integrated with the actuator and when the actuator is deflected downwardly
and the cable is inserted into the wire receiving openings, the release of the actuator
tends to push the cable back out of contact with the electrical contacts.
[0017] The present invention has also been designed to accommodate a range of wire sizes,
the wire receiving channels 22 are profiled to receive and align conductors of various
diameters, as shown in Figures 7 and 8. This has been accomplished by providing a
wire receiving channel 22 extending vertically within the side walls 24a, 24b of the
terminal receiving cavity 22 as shown in Figures 5 and 7. The wire receiving channel
22 first includes radiused sections 22b which are continuous with planar surfaces
22a. As shown in Figure 7, the worst condition of termination is shown where the electrical
terminal 70 is right justified within the terminal receiving cavity 24 whereas the
conductor C₁ is left justified within the conductor receiving channel 22. However,
the planar surface 22a positions the conductor by providing a tangent surface to the
conductor C₁ to prevent the conductor C₁ from moving further to the left. Furthermore,
the planar surfaces 22a provide tangent surfaces which are within the radius of curvature
of the path formed by arcs 22b. As shown in Figure 7, even with the worst case condition,
the electrical terminal continues to have an overlap from the edge of the terminal
to the center of the conductor, of a distance L₁. Since there is an offset L₁, the
conductor C₁ is mainly gripped between the two opposed contacts 82, 78; rather than
relying on the plastic of the housing for a contact force. The planar surfaces 22a
are only used for alignment.
[0018] As shown in Figure 8, a small conductor C₂ having a diameter D₂ can also be terminated
within the connector again with the surface 22a positioning the conductor within the
wire receiving channel 22 with the overlap of the edge of the terminal and the center
of the conductor of a distance L₂.
[0019] Other advantages of the above mentioned design should be readily apparent. For example,
this electrical connector can terminate electrical conductors having diameters which
are larger than the thickness of the electrical terminals (t), which allows for a
very dense connection system on very close centerlines. Also, since the contacts are
edge stamped, as opposed to stamped and formed, the contacts can also be placed on
very close centerlines. Since the contacts are edge stamped, the normal force is much
higher than a comparably sized stamped and formed terminal.
[0020] Another advantage of this design of electrical connector is that the conductor receiving
openings can be alternately formed as shown in Figure 9 such that every other opening
is a mirror of the previous one. This places adjacent planar surfaces 22a in a parallel
manner which allows for a thin web of material to interconnect the two adjacent openings
thereby allowing for very close side-by-side spacing.
1. An electrical connector (2) for interconnecting conductors (C) of a multi-conductor
cable to a printed circuit board comprises an electrical terminal housing (4) and
a plurality of electrical terminals (70); the housing (4) has through passageways
(24) for the electrical terminals (70), and has a lower face (34) which mounts proximate
to the printed circuit board and an upper face (16) which accepts the multi-conductor
cable; the terminals (70) are placed in respective passageways (24) within the connector
housing (4), with printed circuit board posts (86) extending beyond the lower face
(34), and conductor receiving portions (78,82) of the terminals (70) disposed proximate
to the upper face (16); the housing (4) also includes a camming member (50) which
is moveable relative to the housing (4) to open the conductor receiving portions (78,82)
of the terminals (70), the electrical connector (2) being characterized in that:
the upper face (16) of the housing (4) is rigidly fixed relative to the camming member
(50), and has a plurality of discrete conductor receiving openings (20) formed within
the periphery of the upper face (16) of the fixed housing (4), the conductor receiving
openings (20) being in communication with the conductor receiving portions (78,82)
of the terminals (70), the camming member (50) being spaced from the openings (20)
and moveable relative to the housing (4) and the upper face (16), whereby, when the
camming member (50) is moved to actuate and release the conductor receiving portions
(78,82) of the terminals (70), the upper face (16) remains fixed relative to the camming
member (50).
2. The electrical connector of claim 1, characterized in that the terminals (70) are
edge stamped from a strip of metal.
3. The electrical connector of claim 2, characterized in that the terminals (70) comprise
opposed contact sections (78,82) defined by sheared edges of the contacts, the opposed
contact sections (78,82) being aligned with the discrete conductor receiving openings
(20).
4. The electrical connector (2) of claim 3, characterized in that one of the opposed
contact sections is a fixed contact section (78) and the other of the opposed contact
sections is a moveable contact section (82).
5. The electrical connector of claim 4, characterized in that the moveable contact
section (82) is attached to a moveable arm (80) and has at its upper portion a lever
section (84) which is disposed proximate to the upper face (16).
6. The electrical connector (2) of any of claims 1-5 characterized in that each terminal
passageway (24) comprises a channel (24a) to receive the individual moveable arms
(80), the channels (24a) having an upper surface (27) which is lower than the lever
sections (84), which disposes the lever sections (84) into an open channel (25) in
the housing (4).
7. The electrical connector of claim 6 characterized in that the camming member (50)
is disposed within the open channel (25), each lever section (84) having a dedicated
camming surface (56) in contact therewith, the individual camming surfaces (56) being
separated by a plurality of side-by-side walls (30) to isolate the lever sections
(84).
8. An electrical connector of the type for interconnecting a plurality of electrical
conductors (C) to further conductive elements, the connector (2) having an insulating
housing (4) retaining a plurality of electrical terminals (70) within terminal passageways
(24) of the housing (4), the connector housing (4) having conductor receiving openings
(20) therein which are in alignment with conductor receiving sections (78,82) of the
terminals (70), the connector (2) being characterized in that the conductor receiving
openings (20) comprise axially extending passageways comprising arcuate sections (22b)
contiguous with further surfaces (22a) which extend inwardly of the radius of curvature
of the arcuate sections (22b), whereby the conductors (C) are aligned towards the
center of the passageway by the further surfaces (22a).
9. The electrical connector (2) of claim 8, characterized in that the further surfaces
(22a) are defined by planar surfaces (22a).
10. The electrical connector (2) of any of claims 1 to 7 characterized by features
of claim 8 or 9.