U.S. patent number 3,879,099 [Application Number 05/394,362] was granted by the patent office on 1975-04-22 for flat fexible cable connector assembly including insulation piercing contacts.
This patent grant is currently assigned to AMP Incorporated. Invention is credited to Howard Richard Shaffer.
United States Patent |
3,879,099 |
Shaffer |
April 22, 1975 |
Flat fexible cable connector assembly including insulation piercing
contacts
Abstract
A connector assembly is disclosed for terminating
multi-conductor flat flexible cable with contacts which pierce the
cable insulation to make good electrical and mechanical engagement
with all types of cable conductors, in particular round wire and
stranded wire. Each contact is die stamped from sheet material and
has a body portion with a pin or socket electrical termination
means extending from one side and a pair of spaced arms extending
from another side in cantilever fashion. Forked projections extend
from the free end of each arm and are angularly offset with respect
to both the plane of the contact and to one another in order to
engage in an interdigitated fashion. The connector assembly
includes a multi-part housing including a contact block mounted in
a housing shell and two mating housing members pivotally mounted in
the housing shell and adapted close the contacts on an associated
cable and provide strain relief for the cable.
Inventors: |
Shaffer; Howard Richard
(Harrisburg, PA) |
Assignee: |
AMP Incorporated (Harrisburg,
PA)
|
Family
ID: |
23558641 |
Appl.
No.: |
05/394,362 |
Filed: |
September 4, 1973 |
Current U.S.
Class: |
439/397;
439/470 |
Current CPC
Class: |
H01R
12/675 (20130101) |
Current International
Class: |
H01R
11/11 (20060101); H01R 13/58 (20060101); H01R
11/20 (20060101); H01R 11/12 (20060101); H01R
13/46 (20060101); H01r 011/20 (); H01r
013/58 () |
Field of
Search: |
;339/17F,97-99,13C,13M,105,107,139,141,142,176MF,174,206,208,210 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1,394,871 |
|
Mar 1965 |
|
FR |
|
544,048 |
|
Jan 1956 |
|
BE |
|
1,200,801 |
|
Aug 1970 |
|
GB |
|
Primary Examiner: Frazier; Roy D.
Assistant Examiner: Staab; Lawrence I.
Attorney, Agent or Firm: Egan, Esq.; Russel J.
Claims
What is claimed is:
1. An insulation piercing contact for making good electrical and
mechanical engagement with an associated insulated conductor,
comprising:
a planar body portion,
a matable electrical connection member extending from one side of
said body portion;
a pair of cantilever arms extending from another side of said body
portion and lying substantially in the plane of said body
portion;
a forked projection on the free end of each of said arms, each said
forked projection including at least two tines defining a plane,
said forked projections being directed towards one another with
their respective planes intersecting by being angularly offset with
respect to both each other and to the plane of said body portion
whereby bringing said arms together causes said tines of said
forked projections to come together in interdigitated fashion to
pierce the insulation of an insulated conductor and entrap the
conductor therebetween.
2. The contact according to claim 1 wherein said cantilever arms
diverge from each other.
3. The contact according to claim 1 wherein said forked projections
are substantially perpendicular to the axis of the conductor
engaged thereby.
4. The contact according to claim 3 wherein said cantilever arms
have a bent configuration in the plane of said body portion and
intermediate the ends thereof whereby said forked projections
follow a substantially straight path as said arms are brought
together.
5. The contact according to claim 1 further comprising:
at least one locking lance extending from said body portion
transversely of the plane thereof.
6. The contact according to claim 1 wherein said matable electrical
connection member is a socket.
7. The contact according to claim 1 wherein said matable electrical
connection member is a pin.
8. A connector assembly for terminating flat flexible cable having
a plurality of insulated conductors comprising:
a contact block having a plurality of through passages therein,
a like plurality of contacts each positioned in a respective one of
said passages, each said contact including a planar body portion,
an electrical connection terminal extending from one side of said
body portion, a pair of cantilever arms extending from another side
of said body portion and lying substantially in the plane thereof,
a forked projection at the free end of each said arm, each said
forked projection including at least two tines defining a plane,
said forked projections being directed towards one another with
their respective planes intersecting by being angularly offset with
respect to each other and the plane of said body portion,
and a pair of mating housing members pivotally attached to said
contact block and adapted to act against said arms to bring said
projections into interdigitated engagement with conductors of said
flat flexible cable entrapped and engaged by said tines.
9. A connector assembly according to claim 8 further
comprising:
a housing shell surrounding said contact block, said shell
including a hood portion having a forwardly directed flange
encompassing and protecting said electrical connection terminals, a
rear portion, and means securing said two portions together.
10. A connector assembly according to claim 9 wherein said rear
portion of said housing shell and said contact block define upper
and lower channels,
each said mating housing member having an arcuate flange adapted to
engage in a respective one of said channels whereby said members
are pivotally attached to said connector block.
11. A connector assembly according to claim 10 wherein said mating
housing members are of different transverse widths,
further comprising keying means on the arcuate flange of the wider
of said members and the associated channel preventing the insertion
of the narrower member into the keyed channel.
12. A connector assembly according to claim 11 wherein said keying
means comprises:
a slot formed in the arcuate flange of said wider member, and
a fixed stud formed in said wider channel.
13. A connector assembly according to claim 8 further
comprising:
a plurality of grooves in adjacent faces of said mating housing
members, each groove adapted to frictionally engage respective arms
of said contacts.
14. A connector assembly according to claim 13 wherein each said
groove has an enlarged portion at the blind end adapted to receive
the angled forked projection of the associated contact.
15. A connector assembly according to claim 8 further
comprising:
strain relief means on said mating housing members.
16. A connector assembly according to claim 15 wherein said strain
relief means comprises a plurality of interfitting transverse
ridges on mating surfaces of said mating housing members forming a
tortous path therebetween.
17. A connector assembly according to claim 8 further
comprising:
locking means adapted to secure said mating housing members
together in a closed condition.
18. A connector assembly according to claim 17 wherein said locking
means are integral with said mating housing members.
19. A connector assembly according to claim 18 wherein at least a
portion of said locking means is profiled to serve as guide means
for the cable.
20. A connector assembly according to claim 8 further
comprising:
a contact locking ridge extending transversely on each side mating
housing member and adapted to lie closely adjacent a rear surface
of said contact block when said members are in a closed condition.
Description
BACKGROUND OF THE INVENTION
1. The Field of the Invention
The present invention relates to an improved multi-conductor flat
flexible cable connector assembly and in particular to an
insulation piercing contact capable of making good mechanical and
electrical engagement with all types of conductors, including round
wire and stranded wire.
2. The Prior Art
There are many problems involved in providing good electrical
termination for flat flexible cable, particularly cable having
round wire or stranded wire conductors. Most of the known
termination methods and contacts have required some sort of
insulation stripping or other cable preparation prior to attaching
the contacts. Many of the known contacts that can be applied
directly through the cable insulation have not been able to provide
satisfactory mechanical and electrical engagement with the
conductors of the cable. This has been the case particularly in
instances when the cable conductors are round wires or stranded
wires. Insulation piercing contacts have displayed a tendency to
unwind stranded wire, so that good mechanical engagement cannot be
made, and to sever either the round or stranded wire with the
obvious deleterious effects to the cable.
SUMMARY OF THE INVENTION
The subject connector assembly has a plurality of insulation
piercing contacts. Each contact includes a base portion having a
pin or socket extending from a first side and a pair of cantilever
beams extending from another side. A forked projection on the free
end of each cantilever arm is directed toward the other arm and is
angularly offset with respect to both the other forked projection
and the plane of the contact so that they pierce the cable
insulation within each other's slot in interdigitated fashion. The
connector housing includes a contact receiving block and two mating
housing members pivotally attached to the receiving block and
frictionally engaging the arms of each contact. Each mating housing
member also has interengaging locking means and cable strain relief
means.
It is an object of the present invention to construct an insulation
piercing contact and connector assembly which can be used to
terminate multi-conductor flat flexible cable and which can be
applied to said cable without special tooling.
It is another object of the present invention to produce an
insulation piercing contact and connector assembly for use in
terminating multi-conductor flat flexible cable in which the
contacts pierce the insulation of the flat flexible cable during
the attachment of the connector thereto and make good electrical
and mechanical engagement with the cable conductors.
It is a further object of the present invention to construct an
insulation piercing contact and connector assembly for terminating
flat flexible cable having round conductors of either the single or
multi-strand type.
It is yet another object of the present invention to produce an
insulation piercing contact and connector assembly which may be
used to terminate flat flexible cable and is mateable with similar
existing terminal connectors.
The foregoing and other objects of the present invention will
become readily apparent to those skilled in the art from the
following detailed description taken with reference to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the subject connector assembly
fixed to one end of a multi-conductor flat flexible cable;
FIG. 2 is a vertical section through the subject contact and
connector assembly in the open condition ready to be attached to a
flat flexible cable;
FIG. 3 is a vertical section, similar to FIG. 2, showing the
subject contact and connector assembly secured to one end of a
multi-conductor flat flexible cable;
FIG. 4 is a perspective view of a segment of the upper mating
housing member with a portion of a single contact inserted
therein;
FIG. 5 is a side elevation of a single contact according to the
subject invention;
FIG. 6 is a top elevation of the subject contact shown in FIG.
5;
FIG. 7 is a perspective view showing the engagement of two contacts
with conductors at one end of a segment of multi-conductor flat
flexible cable;
FIG. 8 is a schematic horizontal section through a single conductor
of a flat flexible cable showing the engagement of a contact
therewith; and
FIG. 9 is a detail view of a portion of the subject housing showing
mating locking means.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
The subject connector assembly 10 is shown in FIG. 1 attached to
and forming the termination of a multi-conductor flat flexible
cable 12. The connector assembly 10 includes a two part housing
shell 14, a contact block 16, a pair of mating housing members 18,
20 and a plurality of contacts 22. Each contact 22 includes a body
portion 24 with a pin (as shown) or socket electrical connection
terminal 26 extending from one side and a pair of diverging
cantilever arms 28, 30 extending from another side. A forked
insulation piercing projection 32, 34 extends from the free end of
each arm 28, 30, respectively, at an angle substantially normal to
the plane of the cable 12 to be received therein. Each forked
projection 32, 34 is also angularly offet with respect to the other
forked projection and the plane of the contact (see FIG. 6) so that
the tines of the forked projections form an interdigitated
configuration when the arms 28, 30 are brought together. A friction
fastening lance 36 projects laterally from one side of the body
portion 24.
The metallic housing shell 14 encloses the contact block 16 and has
a forwardly directed hood portion 38, which surrounds and protects
the electrical connection terminal 26 of each contact 22, and a
rear shell 40 secured to the hood portion by tabs 42. The rear
shell 40 includes inwardly directed arcuate flanges 44, 46 which,
together with the rear portion of the contact block 16, define
upper and lower channels 48 and 50, respectively. The contact block
16 has a plurality of bores 52 extending from the front face 54 and
a plurality of slots 56 extending from the rear face 58. Each slot
56 communicates with a respective one of the bores 52. The pair of
mating housing members 18, 20 each have an arcuate lip portion 60,
62 adapted to be received in the upper and lower channels 48, 50,
respectively.
The embodiment of the subject connector shown in FIG. 1 is
asymmetric with the top being somewhat longer than the bottom. For
this reason the upper mating housing member 18 is longer than the
bottom mating member 20 and is provided with a central keying
aperture 64 which mates with a keying projection 66 on the upper
rear end of contact block 16 thus keying the mating housing members
for proper assembly. The mating housing members are provided with
interengaging, transversely extending strain relief projections 68,
70, and 72. They are also provided with interengaging locking means
74, 76. One portion of the locking means, in this case the lances
76, are so spaced as to guide the cable so that the proper
conductor 78 is aligned with the proper contact 24.
Each of the mating housing members also has a plurality of contact
receiving recesses 80 (see FIG. 4) in which the arms 28 and 30 of
each contact are frictionally received. Each recess 80 includes an
arm channel 82 and an enlarged profiled end recess 84. The channels
82 are of two different lengths so that the adjacent enlarged
profiled end recesses 84 are offset thus allowing the contacts to
be more closely spaced.
The subject contact and connector are assembled in the following
fashion, the receptacle block 16 is pre-loaded with a plurality of
contacts 22 with the electric connection terminals 26 projecting
from the front face 54. The hood portion 38 and rear portion 40 of
the housing shell 14 are assembled over the preloaded contact block
16 and secured together by tabs 42. The mating housing members 18
and 20 are pivotally attached to the assembly by inserting lip
portions 60, 62 into the upper and lower channels 48, 50,
respectively. The arms 28, 30 of the contacts 22 are frictionally
engaged in the recesses 80. The friction developed between the
plurality of contact arms and the mating housing members is
sufficient to hold the mating housing members in the assembly in
this open position. The thus completed assembly is shipped in this
fashion and subsequently assembled with a flat flexible cable by
inserting the cable between the open mating housing members 18, 20
and between the spread contact arms 28, 30, as shown in FIG. 2.
When the cable 12 is fully inserted into the housing, the mating
housing members 18, 20 are brought together until the locking means
74, 76 engage and the strain relieving members 68, 70, and 72 grip
the cable 12.
As the mating housing members 18 and 20 are brought together, they
engage and drive the arms 28, 30 of the contacts 22 together, the
shorter contact arms being engaged and moved first. The closing
movement of the arms causes the lance shaped ends of the forked
projections to pierce the insulation of the cable and form a closed
substantially oval configuration surrounding the conductors of the
cable so that they will all be firmly engaged as shown
schematically in FIG. 8. It will be noted that the arms 28, 30 have
been shown with a bend intermediate their connection to the contact
body 24 and forked projections 32, 34, respectively. The purpose of
this bend, as mentioned above, is to align the forked projections
so that they are normally substantially perpendicular to the plane
of the cable and will follow a more or less straight line as the
penetrate the cable insulation. This additional bend is optional
and the same function can be accomplished by appropriate adjustment
of the geometry of the arms and forked projections.
The forward edges 86 and 88 of the mating housing members 18 and
20, respectively, are preferably disposed to lock contacts 22 in
the contact block 16 when the members are themselves locked
together. This locking of the contacts against movement is in
addition to that accomplished by the arms 28 and 30 being retained
in slots 80.
The subject contact and connector assembly provide a ready means of
attaching terminals to flat flexible cable, including the cables
with round connectors. The connector assembly allows for all
contacts to be engaged with the cable at one time and with a single
motion. No tools or special equipment is required to effect the
connection and pin and socket patterns can be arranged for mating
with existing connectors. The contacts are insulation piercing so
that there is no requirement for stripping or separation of the
wires. The cable is tightly gripped between the portions of the
housing so that there is a provision for strain relief of the
cable.
The forked projections of the subject contact pierce the cable
insulation from opposite sides of the conductor. The forked
projections have an angular displacement with respect to each other
so that they pierce within each other's slot. The result is that
when the conductors are engaged from opposite sides, movement of
the conductor is controlled preventing the conductor from being
bent or severed or, if it is a stranded wire conductor, becoming
untwisted or separated. The result is a good penetration by the
forked projections and good contact control between the conductors
and the contact.
One of the problems in making a connector assembly for terminating
flat flexible cable and still mating with existing connectors is
the difference between the centerline distances of the cable
conductors and the contacts. In one case the difference may be
minimal and wherein another case it may be a critical factor. This
means that the contacts may not be aligned with the conductors in
all cases. In order to overcome this, the two mating halves of the
connector housing may be designed with the contact slots diverging
toward the free end. The contacts thus can be positioned directly
over each conductor of the cable while providing the desired
spacing of the contacts.
The latching means shown in FIG. 9 is but an example of one
satisfactory means for effecting the desired locking of the mating
housing members and guidance for aligning the cable. It is quite
clear that other locking means, including C shaped metal clamps
fitting externally over the housing members, would be equally as
acceptable. The cable guidance function could likewise be
accomplished by edge tabs or flanges on one of the mating housing
members.
The present invention is subject to many modifications and
variations without departing from spirit or essential
characteristics thereof. The present embodiment is therefore to be
considered in all respects as merely illustrative and not
restrictive.
* * * * *