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Description  |
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FIELD OF THE INVENTION
The invention is directed to a connector for terminating high density flat
cable. In particular, the high density flat cables are accurately
positioned in the connector and terminated to the terminals without the
use of conventional insulation displacement type terminations, thereby
insuring that a much more reliable electrical connection will be effected.
BACKGROUND OF THE INVENTION
Connectors for the termination of flat flexible cable are well known in the
industry. One example is disclosed in U.S. Pat. No. 3,696,319, entitled
Flat Conductor Cable Connector. The connector disclosed teaches of a
connector in which bared cable conductors of a flat conductor cable are
bent around an insulating nose and the nose is inserted into a recess in a
terminal carrying block so that each terminal engages a single conductor.
The desired relationship between the terminals and nose, when fully
inserted, is assured by a tang or stop which projects from the terminal
into the path of the nose. Preferably the nose is provided with a
plurality of ridges and valleys along its length so that the individual
conductors lie in the valleys and are separated from adjacent conductors
by ridges.
U.S. Pat. No. 4,749,371 shows another example of a connector for use with
flat cable. The invention is characterized in that a contact housing
having plural signal contact members and plural ground contact members are
disposed alternately and in parallel one with another within the housing.
Respective leading portions of the contact members are projected into an
internal space formed at a rear portion thereof. A cable base is provided
for connection to a flat cable comprising plural signal conductors and
plural ground conductors which are disposed alternately and in parallel
one with another. Respective naked end portions of the conductors are
mounted at least along one of an upper and lower surface thereof and a bus
bar is connected to the naked end portions of the ground conductors. By
inserting the cable base into the internal space of the contact housing, a
leading portion of each of the signal contact members may be brought into
pressure contact with the end portion of the corresponding one of the
signal conductors, and a leading portion of each of the ground contact
members may be brought into contact with a part of the end portion of the
corresponding one of the ground conductors that is in contact with the bus
bar.
Although the prior art connectors described herein, and many other types,
operate effectively to terminate ribbon cable which have sufficient
spacing provided between the conductors, a problem arises when the spacing
between the conductors is reduced. In particular, when the spacing between
the conductors is in the range of 0.5 mm (0.0198 inches), the prior art
connectors will not provide the electrical connection required.
It would therefore prove advantageous to provide an electrical connector in
which the spacing of the terminals did not depend upon the molding
tolerances of the connector. This would insure that the spacing of the
terminals would correspond to the spacing of the conductors in the cable,
thereby providing a positive electrical connection therebetween.
SUMMARY OF THE INVENTION
The invention is directed to an electrical connector for electrically
connecting a first electrical component to a second electrical component.
The electrical connector has a housing with a first major surface and a
second major surface. A recess is positioned in the housing and extends
from the first major surface to the second major surface. A plurality of
terminals are positioned in the recess. The terminals have retention
portions with sharp outer edges which cooperate with securing means of the
housing to position and maintain the terminals within the recess. Whereby,
as the terminals are inserted into the recess, the sharp outer edges
cooperate with the securing means to displace portions of the securing
means.
A method of inserting the terminals into the housing is also described. The
terminals are positioned in terminal receiving grooves provided on an
insertion tool. The loaded tool is then aligned with a recess provided in
the housing. The insertion tool and terminals are inserted into the recess
of the housing and the terminals are removed from the insertion tool. The
terminals are secured to the housing such that the spacing provided
between the terminals is maintained, insuring that the center line spacing
of the terminals is accurately controlled.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a connector according to the present
invention, a cable alignment bar and a strain relief member are exploded
from the housing of the connector.
FIG. 2 is an exploded perspective view of the connector assembly, similar
to that of FIG. 1, with terminals and a cable exploded from respective
portions of the connector assembly.
FIG. 3 is a perspective view of the terminals positioned on an alignment
tool just prior to the terminals and alignment tool being inserted into
the housing of the connector assembly.
FIG. 4A is a cross-sectional view of the alignment tool showing respective
terminals in engagement with the alignment tool.
FIG. 4B is a cross-sectional view similar to that of FIG. 4A showing the
respective terminals and alignment tool inserted into a recess of the
housing.
FIG. 5 is a cross-sectional view of a termination tool with an alignment
bar and cable positioned in the initial position.
FIG. 6 is a cross-sectional view similar to that of FIG. 5, showing the
termination tool in an intermediate position or cutting position.
FIG. 7 is a cross-sectional view similar to that of FIG. 6, showing the
termination tool in a final or termination position.
FIG. 8 is a cross-sectional view of a fully assembled connector assembly.
FIG. 9 is perspective view of the alignment tool with several terminals
positioned thereon and a carrier strip positioned proximate the tool.
FIG. 10 is a perspective view of the fully assembled connector assembly
before it is mated with a mating connector.
DETAILED DESCRIPTION OF THE INVENTION
As best illustrated in FIG. 1 and 2, cable receiving connector assembly 2
has a housing 4, a molded alignment bar 6, a molded liner 8, and a strain
relief member 10. The housing 4 has a first major surface 12 and an
oppositely facing second major surface 14. End walls 16 and side walls 18
extend from the first major surface 12 to the second major surface 14. A
recess 20 is positioned in the housing 4, and extends from the first major
surface 12 toward the second major surface 14. The recess 20 is
dimensioned to receive a plurality of terminals 22 therein, as will be
more fully discussed. Positioned at either end of the recess 20, are
channels 21.
The terminals 22, as best shown in FIG. 8, have pin receiving sections 24
and cable receiving sections 26. The pin receiving sections 24 are
provided proximate the second major surface 14 when the terminals are
inserted into the housing. Lead-in surface 28 and contact areas 30
cooperate with a pin of a mating connector to insure that the terminals 22
are placed in electrical engagement with the pins of the mating connector.
The cable receiving sections 26 have generally U-shaped configurations,
with resilient arms 32 extending from the base portions 34 in a direction
toward the first major surface 12. Provided proximate the free ends of the
resilient arms 32 are contact portions 36. The contact portions 36 extend
inward from the resilient arms 32, as shown in FIG. 8. Base portions 34,
as best shown in FIG. 3, have sharp outer edges 38. These outer edges
cooperate with the dielectric material of the housing 4 to maintain the
terminals 22 in position relative to the housing 4, as will be more fully
discussed. It should be noted that in the particular embodiment shown, the
terminals 22 are 0.010 inches thick and the center line spacing between
terminals is 0.01968 inches.
Referring to FIGS. 1 and 2, strain relief retention sections 40 are
provided on either end wall 16 of the housing 4. The strain relief
sections 40 have openings 42 which extend from the first major surface 12
of the housing toward the second major surface 14. Recesses 44 are
positioned adjacent to the openings 42, and cooperate therewith.
Alignment bar 6 is dimensioned to be received in the recess 20 of the
housing 4. The alignment bar has a first surface 46 and a generally
rounded second surface 48. Side walls 50 and end walls 52 extend from the
first surface 46 to the second surface 48. Conductor receiving recesses 54
extend from the first surface 46, along a respective side surface, across
the rounded second surface 48, and back toward the first surface, to form
recesses into which the individual conductors of the cable can be
manipulated and retained in position. Portions of the dividing walls
between the conductor receiving recesses 54 have been removed along the
rounded second surface 48 to form a channel 51 (FIG. 5) along the length
of the alignment bar 6. Each end wall 52 is configured to be accepted into
the cavities 21 provided on the housing 4, thereby providing the means
required to insure that the ribbon cable remains in electrical engagement
with the terminals of the connector.
The first surface 46 has a bar projection 55 which extends therefrom. The
bar projection 55 extends in a direction away from the second surface 48,
and cooperates with the cable when the cable is inserted onto the
alignment bar.
The molded liner 8, as best shown in FIGS. 2 and 8, has a relatively flat
upper surface 56 and a lower surface 58 which has a recess 60 provided
therein. The recess is dimensioned to allow the bar projection 54 to be
provided therein.
The strain relief member 10 (FIGS. 1 and 2) is made of stainless steel or
some other material having the strength characteristics required. The
strain relief member has a hold down plate 62 which has locking arms 64
which extend from opposed ends thereof. The locking arms 64 have resilient
securing projections 66 which are provided thereon.
As was earlier stated, the spacing provided between the terminals is
minimal due to the fact that the spacing of the conductors of the cable
can be as close as 0.5 mm (0.01968). Consequently, the standard method of
positioning the terminals in the housing is not adequate. Typically, the
terminals are cut from a carrier strip and pushed into terminal receiving
grooves provided about the edges of the cable receiving recess. The
terminals receiving grooves are separated by molded dividers which serve
to align the terminals, thereby insuring that the terminals are properly
positioned relative to the housing. However, when the center line spacing
of the terminals is 0.01968 of an inch, and the terminals are 0.010 of an
inch thick, only 0.009 of an inch is left for the thickness of the
divider. In this limited space, it is practically impossible to mold
dividers which extend from the first major surface of the housing to the
second major surface. Therefore, an alternate means of aligning and
spacing the terminals is required.
In order to accomplish the precise spacing of the terminals, the terminals
22 are removed from the carrier strip and placed in an alignment tool 70,
as best shown in FIGS. 3, 4A, and 4B. The alignment tool 70 is made from
precision ground steel or other material in which the manufacturing
tolerances can be held to a minimum. A plurality of grooves 72 and
dividers 74 are positioned on the surfaces of the alignment tool 70 to
cooperate with the terminals 22 when the terminals are positioned on the
tool.
It is worth noting that the number of terminals required for a connector
can vary depending upon the requirements of the system. However, as the
expense of the alignment tool 70 can be significant, the manufacture of
the various connectors should not require separate alignment tools.
Therefore, the alignment tool can be constructed in a modular fashion,
such that the appropriate number of grooves and dividers can be removed
from the tool if a different connector size in to be employed.
In operation, the terminals 22 are then moved into cooperation with the
tool 70, and the terminals are severed from the carrier strip, as shown in
FIG. 9. As the terminals 22 are inserted onto the tool 70, the contact
portions 36 engage bottom surfaces of grooves 72, thereby creating a
frictional engagement between the terminals and the tool which is of
sufficient force to maintain the terminals on the tool. The configuration
of the grooves 72 and dividers 74 insures that the terminals will be
properly positioned. This positioning is insured because of the precise
manufacturing of the tool.
As is shown in FIG. 9, the pin receiving sections 24 of the terminals 22
are offset from the carrier strip. The pin receiving sections are
staggered to allow for insertion, as well as mating with a mating
connector.
When the tool 70 is fully loaded with terminals 22, the tool is moved into
the recess 20 of the housing 4, as is best shown in FIG. 4B. The tool is
dimensioned to allow for easy insertion and withdraw of the tool from the
recess.
As the tool 70 is moved into the recess 20, the outer edges 38 of the
terminals 22 engage retention portions 68 of the housing 4. As the
insertion continues, the sharp outer edges 38 are driven into retention
portions 68, as best shown in FIG. 2. This is continued until the
terminals are properly seated in the housing. In this position, the outer
edges 38 are forced far enough into the retention portions 68 to provide
the retention force required to insure that the terminals 22 are
maintained in position. With the outer edges 38 positioned in the
retention portions 68, the alignment tool 70 is withdrawn. As the
retention force between the outer edges 38 of the terminals 22 and the
retention portions 68 of the housing 4 is greater than the frictional
engagement between the terminals and the tool, the terminals are retained
in the housing as the tool is withdrawn. With the tool fully extracted,
the tool is again loaded with terminals, and the process is repeated for
the next housing.
Because of the use of the alignment tool, the positioning of the terminals
in the housing is precisely controlled. Therefore, the connector can be
molded in the ordinary way, without the need to provide fragile dividing
walls between the terminal receiving recesses. This also insures that the
price of the connector can be kept to a minimum.
The accuracy of the terminals in the housing is precise and repeatable. As
the alignment tool has precision ground grooves, the precision of the
grooves can be precisely manufactured. Also because of the material used,
the tolerance range of the grooves is minimal, and therefore, the spacing
of the terminals is identical for each connector. The precise and
repeatable spacing of the terminals is extremely important when dealing
with conductors which have small center line spacing and small conductor
thicknesses. Consequently, because of the precision of the alignment tool,
the spacing of the terminals is far superior to that of a connector which
has the terminals aligned by molded recesses in the housing.
With the terminals 22 properly positioned in the housing 4, the alignment
bar 6 is moved into the recess 20. However, before the alignment bar is
moved into the recess, a respective cable 80 must be positioned and
maintained on the alignment bar 6.
Referring now to FIGS. 5 through 7, the preparation and positioning of the
cable 80 on the alignment bar will now be discussed. Ends 82 of the cable
are stripped by means of laser burning or other known methods. As these
methods are well known in the industry, a detailed description will not be
provided. This type of process insures that residue will not be left
between the stripped portions of the conductors of the cable.
With the end 82 of the cable prepared, the alignment bar 6 is moved into
cooperation with the prepared end 82 of the cable, as is illustrated in
FIG. 5. The configuration of the cable is obtained during the laser
burning process, and consequently, no reworking of the cable takes place
in this step. As is shown, the bar projection 55 of the alignment bar 6 is
received within a bent portion of the cable. The exposed conductors 84 of
the end 82 of the cable are positioned in a portion of the conductor
receiving recesses 54, thereby insuring that the spacing required between
the exposed conductor is maintained.
The preassembled subassembly of the alignment bar 6 and the cable 80 is
then inserted into a recess 90 of a termination tool 86, as shown in FIG.
5. In order to insure for the proper alignment of the subassembly into the
tool, the end walls 52 of the alignment bar 6 cooperate with pockets 87 of
the termination tool to prevent the movement of the subassembly relative
to the tool 86.
With the subassembly properly positioned and maintained in the recess 90 of
the tool 86, the exposed portions of the conductors 84 which extend beyond
the alignment bar 6 are bent approximately ninety degrees, as indicated by
the dotted arrow in FIG. 5. The conductors 84 are bent until they rest in
channel 92 of movable support arm 94.
A conductor driving member 96 and conductor support member 98 are moved
into cooperation with the conductors 84. Initially members 96, 98 are
moved in unity toward alignment bar 6, as shown in FIG. 5. This motion
continues until a lead projection 100 of the conductor support member 98
engages the conductors 84 of the cable 80. As is shown in FIG. 6, the lead
projection 100 is positioned in the cavity 51 of the alignment bar 6,
thereby insuring that the lead projection 100 cooperates with the
individual conductors 84, to maintain them in position in their respective
conductor receiving recesses 54. With the conductor support member 98
provided in engagement with the conductors 84, the further downward motion
of the member 98 is prevented. This is due to the fact that member 98 has
a spring member 102 provided therein, which allows the conductor support
member 98 to remain stationary relative to the alignment bar 6 as the
conductor driving member 96 is advanced. The spring member 102 also
insures that an adequate force will be supplied to the exposed conductors,
to insure that the conductors 84 are retained in position relative to the
alignment bar 6 as the termination process continues.
Referring to FIG. 6, the downward motion of the conductor driving member 96
is continued. This causes the conductor driving member 96 to engage the
exposed conductors 84 of the cable 80. It is important to note that
recesses 104 are provided on the leading edge of the member 96. The
recesses 104 cooperate with the respective conductors 84 to insure for the
proper position of the conductors as the termination process continues.
As the conductor driving member 96 is forced downward, the conductors 84
are also forced downward, as viewed in FIG. 7. This motion forces the
conductors against a cutting edge 106 provided on the movable support arm
94. Consequently, as shown in FIG. 7 the extreme ends of the conductors 84
are severed from the cable.
The downward motion of the conductor driving member 96 is continued,
causing the conductors to wrap around the alignment bar 6. Angled surface
108 of the conductor driving member 96 allows the conductors 82 to be
easily wrapped about the bar 6. In order to insure that the conductors 82
are properly positioned in the conductor receiving recesses 54, channels
109 are provided on conductor driving member 96. These channels 109 are
positioned to allow the dividing walls of the recesses 54 to be inserted
therein. This allows the conductor driving member 82 to extend into
recesses 54, thereby insuring that the conductors 82 will be properly
positioned in the recesses, as shown in FIG. 7.
With the conductors 84 properly positioned about the alignment bar 6, the
conductor driving member 96 is retracted. The conductor support member 98
is retained in cooperation with the conductors until the conductor driving
member is completely removed from the ends of the conductors. This insures
that the conductors will remain in position as the member 96 is retracted.
Finally, the conductor support member 98 and the movable support arm 94
are moved from the alignment bar 6 and cable 80, thereby allowing the
assembled cable and alignment bar subassembly to be removed from the tool.
The assembled cable and alignment bar subassembly is inserted into the
recess 20 of the housing, as best shown in FIG. 8. The end walls 52 of the
alignment bar 6 are received in the channels 21 of the recess 20 to insure
that the alignment bar 6 is properly positioned in the recess 20 of the
housing 4. As the bar 6 is into the recess 20, the contact portions 36 of
the terminals 22 enter the conductor receiving recesses 54 of the bar 6.
It should be noted that the resiliency of the arms 32 of the terminals is
adequate to compensate for any slight misalignment between the terminals
22 and the recesses 54.
As the insertion of the bar 6 into the recess 20 occurs, the contact
portions 36 engage the exposed conductors 84 of the cable, causing a
wiping action between the terminals and the conductor, thereby insuring
that a proper electrical connection will be effected.
When the alignment bar 6 is fully inserted into the recess 20 of the
housing 4, the resilient arms 32 of the terminals generate a significant
force on the conductors. This insures that the alignment bar 6 will be
maintained in position, and that the electrical connection between the
terminals and the cable will be reliable over time.
With the alignment bar 6 properly positioned in the housing 4, the molded
liner 8 and strain relief member 10 are positioned over the cable 80. The
strain relief member 10 provides a means to lock the assembly together.
The locking arms 64 of the strain relief member 10 are positioned in the
openings 40 of sections 42 of housing 4, such that the resilient securing
projections 66 are provided in the recesses 44. The cooperation of the
projections 66 and recesses 44 insures that the assembly will remain in
the locked position.
Connector assembly 2 is mated with a mating connector to provide the
electrical path required between the cable and a printed circuit board or
the like.
Changes in construction will occur to those skilled in the art and various
apparently different modifications and embodiments may be made without
departing from the scope of the invention. The matter set forth in the
foregoing description and accompanying drawings is offered by way of
illustration only.
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