U.S. patent number 3,924,923 [Application Number 05/368,387] was granted by the patent office on 1975-12-09 for flat cable electrical connections and methods of making same.
This patent grant is currently assigned to AMP Incorporated. Invention is credited to John Robert Shoemaker.
United States Patent |
3,924,923 |
Shoemaker |
December 9, 1975 |
FLAT CABLE ELECTRICAL CONNECTIONS AND METHODS OF MAKING SAME
Abstract
Parallel conductors in a flat cable are connected to a row of
slotted terminals by punching holes in the cable between adjacent
conductors, locating the portions of the conductors which lie
between the holes in alignment with the slots in the terminals, and
moving the conductors laterally of the plane of the cable into the
slots. A ladder type strip of stuffer or wedging pins is then
located adjacent to the terminals with the pins in alignment with
the slots and the pins are moved into the slots to retain the
conductors in the slots and to urge them against edge portions of
the slots in order to establish electrical contact.
Inventors: |
Shoemaker; John Robert
(Walkerton, NC) |
Assignee: |
AMP Incorporated (Harrisburg,
PA)
|
Family
ID: |
23451007 |
Appl.
No.: |
05/368,387 |
Filed: |
June 8, 1973 |
Current U.S.
Class: |
439/894;
439/398 |
Current CPC
Class: |
H01R
43/01 (20130101); H01R 12/675 (20130101); H01R
4/2445 (20130101) |
Current International
Class: |
H01R
4/24 (20060101); H01R 43/01 (20060101); H01R
009/06 (); H01R 031/02 () |
Field of
Search: |
;339/95-99,17,276,278
;206/46ED,56AB,56F ;174/DIG.3,52S,52PE,84R,84C |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Frazier; Roy D.
Assistant Examiner: Lewis; Terrell P.
Attorney, Agent or Firm: Pitts; Robert W. Raring; Frederick
W. Seitchik; Jay L.
Claims
What is claimed is:
1. A continuous strip of stuffer members, each of said stuffer
members being adapted to be inserted into the conductor-receiving
slot of a contact terminal member for the purpose of retaining a
conductor in the slot, said strip comprising:
two spaced-apart parallel co-planar carrier strips of polymeric
insulating material,
said stuffer members each comprising a stuffer pin which is adapted
to be moved laterally of its axis against a conductor and into said
slot, each of said pins comprising a flat sheet metal member having
parallel side edges, an enlarged center section, and enlarged
ends,
said stuffer members extending between said strips of polymeric
insulating material ladder-rung fashion, said stuffer members being
spaced apart along the length of said carrier strips and having
said enlarged ends adhered to said strips whereby,
upon positioning each of a plurality of conductors in alignment
with the slots of each of a plurality of contact terminals, and
upon positioning a section of said stuffer strip proximate to said
conductors with one stuffer pin parallel to each of said
conductors, and upon subsequently moving said section of stuffer
strip towards said conductors and then moving said stuffer strip
and said conductors into said slots, said conductors will be
engaged by the edges of said slots and thereby establish electrical
contact with said terminals, and said stuffer pins will retain said
conductors in said slots.
2. A continuous strip of stuffer members, each of said stuffer
members being adapted to be inserted into the conductor-receiving
slot of a contact terminal member for the purpose of retaining a
conductor in the slot, said strip comprising:
two spaced-apart parallel co-planar carrier strips of polymeric
insulating material,
said stuffer members each comprising a stuffer pin which is adapted
to be moved laterally of its axis against a conductor and into said
slot,
said stuffer members extending between said strips of polymeric
insulating material ladder-rung fashion, said stuffer members being
spaced apart along the length of said carrier strips and having
their ends adhered to said strips and
a third carrier strip, each of said pins being integral with said
third carrier strip, said third carrier strip extending beside one
of said polymeric carrier strips and parallel to the edge thereof
which is remote from the other one of said polymeric carrier
strips, said third carrier strip being removable from said strip
upon insertion of said pins into said slots whereby,
upon positioning each of a plurality of conductors in alignment
with the slots of each of a plurality of contact terminals, and
upon positioning a section of said stuffer strip proximate to said
conductors with one stuffer pin parallel to each of said
conductors, and upon subsequently moving said section of stuffer
strip towards said conductors and then moving said stuffer strip
and said conductors into said slots, and removing said third
carrier strip from said stuffer strip said conductors will be
engaged by the edges of said slots and thereby establish electrical
contact with said terminals, and said stuffer pins will retain said
conductors in said slots.
Description
BACKGROUND OF THE INVENTION
This invention is directed to improved electrical connections
between the conductors of a flat conductor cable and the plate-like
wire-receiving portions of terminals contained in an electrical
device such as a multi-contact electrical connector.
Application Ser. No. 147,569 now U.S. Pat. No. 3,760,335 discloses
and claims a multi-contact electrical connector having contact
terminals therein which have plate-like conductor receiving
portions. These conductor-receiving portions of the terminals have
slots extending into one edge thereof for the reception of
electrical conductors, the arrangement being such that when a
conductor is moved laterally of its axis and into a
conductor-receiving slot, the edges of the slot engage the
conductor and establish electrical contact therewith. As explained
in application Ser. No. 147,569 now U.S. Pat. No. 3,760,335 a
plurality of conductors can be simultaneously inserted into the
conductor-receiving portions of all of the terms so that the
connector can be installed on the wires in an extremely short time
and by a simple operation.
Application Ser. No. 310,056 now abandoned discloses a method and
apparatus for connecting the conductors of a flat cable to the
terminals of a connector of the general type shown in application
Ser. No. 147,569 now U.S. Pat. No. 3,760,335. The flat ribbon-like
conductors of the flat conductor cable are inserted into the slots
of the platelike portions of the terminals and a wedge member or
stuffer member, in the form of a pin, is also inserted into each
slot. The stuffer or wedge maintains the thin ribbon-like
conductors in engagement with the edges of the slots of the
terminals to provide a low resistance electrically stable
connection of the ribbon conductors to the terminals.
The instant invention is directed to the achievement of improved
electrical connections between the conductors of a flat cable and
the conductor receiving portions of slotted plate-like terminals.
Particularly, the invention is directed to the achievement of
improved stuffer or wedging pins, improved methods of installing
the connector on the cable and to improved finished connections
between flat cables and electrical connectors.
In accordance with a preferred embodiment of the invention, holes
are punched in the cable between adjacent conductors and the
portions of the conductors which separate the holes and the cable
are located in alignment with the slots in the terminals. The
conductors of the cable are moved laterally of the plane of the
cable into the slots and a strip of stuffer pins is concominantly
assembled to the connector. This strip contains a plurality of
parallel stuffer pins held in spaced apart relationship in a single
plane by an insulating carrier strip.
Preferred embodiments of the invention are described in detail
below and shown in the accompanying drawing in which:
FIG. 1 is a fragmentary perspective view of a multi-contact
electrical and connector of a type adapted to have the conductors
of a flat cable connected thereto in accordance with the
invention.
FIG. 2 is a perspective view of a section of flat cable having a
plurality of ribbon-like conductors therein, one end of this cable
having been prepared for attachment to an electrical connector in
accordance with the principles of the invention.
FIG. 3 is a perspective view showing the manufacture of a strip of
stuffer pins of a type used in the practice of the invention.
FIG. 4 is a plane view of a section of stuffer pin strip in
accordance with the invention.
FIG. 5 is a fragmentary perspective view showing the end portion of
the cable of FIG. 2 positioned with its conductors in alignment
with the conductor-receiving portions of the terminals of a
connector and showing a stuffer pin strip in alignment with the
conductors of the cable; this view shows the relative positions of
the terminals, the cable, and the stuffer pin strip at the
beginning of the conductor insertion operation.
FIG. 6 is a perspective view of the rearward side of a connector
having the conductors of a flat cable connected to the terminals of
the connector.
FIG. 6A is a fragmentary plan view of a connector having a cable
attached thereto.
FIG. 7 is a perspective view of a strain relief device which is
assembled to the connector to maintain the conductors in the
terminals and to clamp the cable adjacent to the connector for
strain relief purposes.
FIG. 8 is a sectional side view of a connector installed on the
conductors of the flat conductor cables.
FIG. 9 is a fragmentary perspective view showing a connector
installed on intermediate portions, rather than the end portions of
cables.
FIG. 10 is a plan view of a modified form of stuffer pin strip.
FIG. 11 is a perspective view of a section of flat cable having
conventional wires therein rather than flat conductors which has
been prepared in accordance with the invention for connection to
the terminals in a connector.
FIG. 12 is a perspective view showing the cable of FIG. 11 and a
connector.
Referring first to FIG. 2, the instant invention is directed to the
achievement of improved electrical connections between the flat
ribbon-like conductors 76 of a flat cable 2 to the terminals of a
connector described below. As shown in FIG. 2, the flat conductors
are contained in a web 78 of suitable insulating material such as
Mylar polyethyleneterephthalate in parallel spaced apart
relationship.
The conductor 4 (FIGS. 1 and 8) comprises a housing 6 having a
central body portion 7, a mating side 8, and a rearward side 10.
Contact receiving cavities 12 extend leftwardly from the rearward
side to the mating side and open onto the surfaces 14, 14' of a rib
13 which projects centrally from the body portion. As will be
apparent from FIG. 1, the connector is substantially symmetrical
about its horizontal center line and the same reference numerals,
differentiated by prime marks, are used for the corresponding
structural elements on the upper and lower sides of this center
line. In the interest of brevity, only the upper portion of the
connector is described in detail.
A hood 16 projects forwardly from body portion 7 in surrounding
relationship to the rib 13, this hood being adapted to surround a
complementary connector part when mated therewith as fully
described in the above-identified application Ser. No. 147,569.
The individual contact terminals 18 which are contained in the
cavities 12 have a central shank portion 20, a contact arm of
reduced width 22 which extends from the shank, and a pair of spaced
apart plate sections 24, 26 on the rearward end of the shank. The
plate sections are joined to each other at their upper ends by
parallel straps 28 between which a conductor is moved into slots
30, 32 in the plate sections when the conductor is to be
electrically connected to the terminal.
A rib 34 projects from the rearward side of the housing and has a
surface 36 on which the shank portions 20 of the terminals are
supported. Vertically extending barrier plates 38 extend upwardly
from the surface 36 and function to isolate the individual
terminals each from the other. At their right-hand ends, as viewed
in FIG. 1, the dimensions of these barrier plates are such that
their edges are beyond the plate sections 24, 26 and straps 28. The
barriers are of reduced height adjacent to the body portion of the
housing as shown at 40 and merge with a rearwardly facing surface
42 which extends normally of the surface 36. Surface 42 merges with
a ledge 44 which is parallel to surface 36 and this ledge in turn
merges with another rearwardly facing surface 46 of the
intermediate body portion 7 of the housing.
When the conductors 76 are to be connected to the conductor
receiving portions of the terminals 18, holes 80 are punched in the
cable between adjacent conductors and the end portion of the cable
is located adjacent to the rearwardly facing surface 46 of the
housing with the individual conductors in alignment with the slots
of the terminals as shown in FIG. 5. A section of stuffer pin strip
86 is located relatively above the cable with stuffer pins 88 in
alignment with the individual conductors. This stuffer pin strip
(FIG. 4) carries a plurality of spaced apart flat stuffer pins 88
having centrally enlarged portions 90. The pins have enlarged ends
92 which are bonded to spaced-apart parallel carrier strips 94 of
suitable plastic as described below.
When the electrical connections between the conductors and the
terminals are formed, the stuffer pin strip and the conductors of
the cable are simply moved downwardly as viewed in FIG. 5 and into
the inner portions of the slots 30, 32. The edges of the slots
penetrate the insulation on the under sides of the conductors and
establish electrical contact therewith and the conductors become
wrapped around the pins so that the pins maintain the conductors in
contact with the edges of the slots as explained in application
Ser. No. 310,056 now abandoned. The insertion operation as
described above can be carried out with an apparatus of a general
type disclosed in application Ser. No. 310,056 now abandoned or can
in fact, be carried out by simply manually aligning the cable and
stuffer pin strip moving a simple stuffing tool against the pins 88
until the conductors are fully inserted. The insertion apparatus
shown in application Ser. No. 310,056 has a slide member in which a
plurality of insertion punches are mounted. The punches engage the
pins and push the pins 88 and the conductors into the slots 30, 32.
The enlarged center portions 90 of the pins provides a bearing area
for the punches during insertion.
Referring now to FIG. 3, the stuffer pin strip can be manufactured
by simply punching openings in a thin strip of sheet metal to form
two metallic carrier strips 96 with the stuffer pins 88 integral
with, and extending between, these carrier strips ladder-rung
fashion. Pilot holes as shown are ordinarily punched in the carrier
strips 94 at the time of manufacture. The plastic carrier strips 94
are then bonded to the enlarged portions 92 of the stuffer pins 88
and the metallic carrier strips can then be removed by shearing the
enlarged portions of the pins from these metallic carrier strips.
The plastic carrier strips 94 are advantageously of Mylar
(polyethyleneterephthalate) and are provided with a thin film
(about 1 mil) of adhesive comprising a co-polymer of ethylene and
acrylic acid. The enlarged portions of the stuffer pins can then be
heat bonded to the carrier strips and the stuffer pins will thus be
accurately positioned on the plastic carrier strips 94.
It is desirable to provide a cover means as shown in FIGS. 7 and 8
on the rear side of the connector housing in order to retain the
conductors of the cable in the slots of the terminals and to clamp
the cable for strain relief purposes. This cover means comprises
two parts which are identical so that a description of one will
suffice for both.
The upper part in FIG. 7 comprises an elongated web 52 having a
flange 54 depending from its rearward edge and a relatively short
flange 56 depending from its forward edge which is adjacent to the
surface 46 after installation. The external surface of the flange
58 is advantageously cylindrical as shown in FIG. 4 so that it will
confine and clamp the cables against the surfaces 42, 46. A central
flange 60 is provided between the flanges 54, 56 and spaced from
the flange 56 by a distance such that the barriers 38 will be
received within the groove or channel 61 which is defined by the
opposed sides of the two flanges. The dimensions of flanges 56, 60
are such that they serve to hold the cables in the inner ends of
the slots 30, 32 of the terminals and prevent any lateral movement
of the conductors which might degrade the electrical connections of
the conductors to the terminals.
An end flange 62 depends from the righthand end of the upper cover
part and an integral latching strap 66, having a central opening
68, projects downwardly from the lower end of this flange. Another
end flange 64 depends from the lefthand end of the web 52 and has a
central recess 70 on its outwardly facing side which is adapted to
receive the latch strap 66' of the lower cover part, a locking boss
72 being provided in this recess for cooperation with the locking
strap 66'. When the parts, as viewed in FIG. 7, are moved towards
each other, the straps 66, 66' will then be flexed outwardly until
the bosses enter the openings 68, 68'. The opposed surfaces 74, 74'
and 76, 76' of the end flanges 62, 64 bear against the sides 48 of
the central rib 34 of a connector housing so that the cover is
restrained against movement.
Both the housing and the cover member are advantageously formed of
a plastic insulation material, the material for the cover being
such that the latch straps 66, 66' are stiffly flexible to permit
assembly of the cover parts to the connector.
After the conductors have been inserted into the slots of the
contact terminals in the manner described above, the cover 50 is
assembled to the housing by positioning the two cover parts on the
opposite sides of the rib 34 as shown in FIG. 7 and moving them
towards each other until they are latched to each other. The
flanges 54, 54' are spaced apart in the assembled cover member to
define an opening 78 through which the incoming cables extend.
Since the cables 2, 2' are usually quite thin, it may be desirable
to place a block of compressible material 97, such as a soft
rubber, between the cables prior to assembly of the cover to the
connector housing. The block is compressed as shown in the drawing
so that the cables are clamped between opposed edges of the flanges
54, 54'. If a tensile pull is applied to the cables, the forced
applied will be transmitted from the cables to the back cover
rather than to the terminals in the housing.
As shown in FIG. 9, an intermediate portion of the cable can be
connected to the terminals in the connector by punching the holes
at the desired location connecting the conductors 2 to terminals as
described above, and then assembling the back cover to the
housing.
Several of the advantages of the invention will be apparent from
the foregoing description, for example, the fact that the holes 80
are spaced from the end of the cable ensures that the conductors
can be easily and precisely located in alignment with the conductor
receiving slots 30, 32 of the terminals. Also, the fact that the
stuffer pins are held on the plastic carrier strips 94 facilitates
the location of the plastic strip with reference to the conductors.
The use of the stuffer pin strip 86 is advantageous for the further
reason that during insertion of the conductors of the cable and
insertion of the stuffer pins into the slots of the terminals, the
stuffer pin strip is moved as a unit and the individual stuffer
pins remain on the carrier strips 94. Because of this, it is
possible to retain close control of the individual stuffer pins
during insertion and the possibility of one or more pins being
improperly inserted is reduced.
The operation of installing the connector on the cables thus is a
relatively simple one in which there is little possibility of error
and which can be carried out without a high degree of operator
skill. If desired, the conductors can be formed or U-ed when the
windows or openings are punched to facilitate their entry into the
slots of the terminals. Whether or not this step is desirable will
depend upon the size of the conductors relative to the width of the
slots at their upper ends.
The teachings of the invention can also be employed to advantage
when it is desired to connect the conventional round wire
conductors 102 of a cable 98 to terminals in a connector. The cable
98 is similar to previously described cable 2 excepting that the
conductors are ordinary round wires, either solid or stranded. As
shown in FIG. 11, the web material can be removed adjacent to the
end of the cable and the conductors accurately positioned over the
terminals. The conductors are then moved into the slots and stuffer
pins need not necessarily be used in this embodiment although they
may be used if desired to improve the electrical and mechanical
qualities of the connections between the conductors and the
cables.
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.
* * * * *