U.S. patent number 3,613,049 [Application Number 04/881,064] was granted by the patent office on 1971-10-12 for connector for flat multiconductor cables.
This patent grant is currently assigned to Bell Telephone Laboratories, Incorporated. Invention is credited to Joseph M. Niedzwiecki.
United States Patent |
3,613,049 |
Niedzwiecki |
October 12, 1971 |
CONNECTOR FOR FLAT MULTICONDUCTOR CABLES
Abstract
A connector for use with multiple conductor flat cables is
disclosed which contains two clamp blocks, a center block and a
number of contact members. The clamp blocks are positioned on
either side of the center block and the contact members are located
within the body of the center block.
Inventors: |
Niedzwiecki; Joseph M. (Brick
Town, NJ) |
Assignee: |
Bell Telephone Laboratories,
Incorporated (Murray Hill, Berkeley Heights, NJ)
|
Family
ID: |
25377704 |
Appl.
No.: |
04/881,064 |
Filed: |
December 1, 1969 |
Current U.S.
Class: |
439/329;
439/495 |
Current CPC
Class: |
H01R
12/613 (20130101); H05K 3/365 (20130101); H05K
2201/0133 (20130101) |
Current International
Class: |
H01r 013/54 () |
Field of
Search: |
;339/17,75,92,176,278 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McGlynn; Joseph H.
Claims
I claim:
1. A connector adapted for use with multiple conductor cables
comprising facing outer bearing surfaces located on two clamp
blocks disposed in register with each other, inner bearing surfaces
located on a center block in facing relationship to said outer
bearing surfaces to form two conductor-accommodating recesses,
contact members for extending electrical paths from one recess to
the other, and means for urging said clamp blocks towards said
center block to compress conductors located in said recesses
against said contact members, CHARACTERIZED IN THAT each contact
member is a unitary wire extending internally through said center
block, has deflectable sections located in each recess for engaging
conductors pressed between said inner and outer bearing surfaces,
and has an intermediate section bearing against a solid interior
portion of said center block whereby electrical contact is readily
made between conductors located in opposite recesses.
2. A connector in accordance with claim 1 wherein each of said
contact members has an S-shaped configuration.
3. A connector in accordance with claim 2 wherein said deflectable
sections are located at the opposite ends of each connector member
and extend into said recesses to exert a pretensioned force against
conductors clamped between said inner and outer bearing
surfaces.
4. A connector in accordance with claim 2 wherein one of said clamp
blocks also includes a number of fixed contacts disposed in a row
and said contact members are aligned in register with said fixed
contact members so as to engage said fixed contact members when
said inner and outer bearing surfaces are urged together.
5. A connector for flat cables comprising two clamp blocks disposed
on opposite sides of a center block, said clamp blocks and said
center block having bearing surfaces located in facing relationship
to each other to form a pair of cable-accommodating recesses and
said center block including a group of contact members in which
each contact member has an X-shaped configuration, is made from a
single unitary piece of wire, has an end section projecting into
each of said recesses and includes a center section passing through
the interior of said center block.
6. A connector in accordance with claim 5 wherein each contact
member is made from a piece of preplated wire.
7. A connector in accordance with claim 5 wherein the midpoint of
each contact member is located in the center of said center block
and the ends of said contact member extend above the surface of
said center block to form a pair of serially aligned contact
surfaces in each recess.
8. A connector in accordance with claim 7 wherein at least two of
said ends have hook-shaped deflectable sections projecting into
said recesses.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to connectors for multiconductor cables and
relates particularly to conductors for use with cables which are
flat and flexible.
2. Description of the Prior Art
Conventional multiconductor cables having round cross sections are
not suitable for all wiring applications. For example, where space
is at a premium, the bulk and stiffness of a round cable is often
unacceptable. Consequently, new cable forms have proliferated in
which the conductors are aligned side by side to form a flat and
flexible assembly. The new flat cables, however, are generally not
compatible with old-style connectors. Consequently, flat cable
connectors have been developed to provide a way of connecting flat
cables to each other or to other appropriate electrically
conducting apparatus.
The demand for flat cable connectors is large and growing. Since
small savings in making individual connectors will multiply into
large savings when making many connectors, the increasing demand
for connectors in large numbers requires a design which will keep
manufacturing costs to a minimum. Moreover, it is essential that
each connector be simple to use and that it make and retain good
electrical connection so that installation and maintenance costs
can be kept at reasonable levels. It is imperative, therefore, that
flat cable connectors be available which are simple to use,
inexpensive to make and reliable in operation.
Accordingly, the object of this invention is to achieve
reliability, simplicity for use, and low cost in the manufacture
and application of flat cable connectors.
SUMMARY OF THE INVENTION
In a preferred embodiment of this invention, two clamp blocks are
disposed on either side of a center block. The two clamp blocks and
the center block have facing bearing surfaces and the bearing
surfaces cooperate to form two recesses suitable for accommodating
cables to be joined. Electrical paths are extended between cables
clamped in the two recesses by a group of contact members in which
each contact member is made from a single, unitary piece of wire,
has an end section projecting into each recess and is held in place
by a center section which passes through the middle of the center
block.
According to one feature of this invention, combining all of the
connector elements into three basic parts simplifies connector
usage.
According to another feature of this invention, locating each
contact member within the body of the center block improves
reliability by protecting the contact members from accidental
damage attributable to causes arising outside the connector.
According to another feature of this invention, each contact member
is made from a single unitary wire so that savings in manufacturing
costs can be achieved by plating each contact member before it is
inserted into the body of the center block.
DESCRIPTION OF THE DRAWING
FIG. 1 is an exploded view taken in perspective, showing the
location of a typical flat cable with respect to the center block
and the two clamp blocks in a flat cable connector constructed in
accordance with this invention;
FIG. 2 is an exploded end elevation of the parts shown in FIG. 1
with the addition of a second flat cable and illustrates the
relationship of the parts of the flat cable connector in respect to
each other;
FIG. 3 is an end elevation view taken in section showing an
assembled flat cable connector electrically joining two flat
cables;
FIG. 4 is an end elevation view of the components shown in FIG. 3,
except that one flat cable has been replaced with a series of fixed
contact members located in one of the clamp blocks;
FIG. 5 is a side elevation view of a flat cable connector made in
accordance with this invention;
FIG. 6 is a section view taken along lines 6--6 of FIG. 5
illustrating a second form of contact member; and
FIG. 7 is a plan view of the connector member shown in FIG. 6.
DETAILED DESCRIPTION
Referring to FIG. 1, a flat cable connector 10 is illustrated which
comprises three basic parts, viz: two clamp blocks 11 and 12 and a
center block 13. In typical use, the two clamp blocks 11 and 12, as
illustrated in FIG. 3, cooperate with the center block 13 to
electrically join a pair of flat cables 14.
As best seen in FIGS. 1 and 2, each flat cable 14 ends in a number
of exposed conductors 15. In order to make a connection, the
exposed conductors 15 are forced against corresponding contact
members 16 which extend between the two cables. In the embodiment
shown in FIGS. 1, 2 and 3, cooperating bearing surfaces 18 and 19
press the conductors 15 against the contact members 16. As best
seen in FIG. 2, the bearing surfaces 18 are located on the clamp
blocks 11 and 12, while the bearing surfaces 19 are located on
opposite sides of the center block 13.
The two clamp blocks 11 and 12 are essentially alike, so a
description of one will suffice for the other. As shown in FIGS. 1
and 2, the clamp block 12 is substantially rectangular in form and
contains a groove 20 and a pair of guide pins 21 (only one shown)
adjacent to the groove 20. As illustrated in FIG. 2, the bearing
surfaces 18 are located on opposite walls of the groove 20. The
clamp block 11 is conveniently made of an insulating plastic
material such as diallyl phthalate and includes an arrangement by
which it can squeeze the center block 13 against the clamp block
12. For example, as shown in FIG. 1, the clamp block 11 may
conveniently contain a pair of holes 22 suitable to accommodate a
pair of bolts 23a and nuts 23b.
The center block 13, as best seen in FIG. 1, is substantially
rectangular in shape. It is conveniently made of an insulating
plastic material such as diallyl phthalate. As can be seen from
FIGS. 1 and 2, the bearing surfaces 19 are interrupted by a number
of slots 24. The slots 24, in turn, are interconnected by a number
of holes 25. The number of slots 24 is determined by the nature of
the cables to be joined. In the embodiment illustrated in FIGS. 1
and 2, a 10-conductor cable is contemplated. Consequently, 10 slots
24 appear in the center block 13.
The slots 24 are divided into two equal groups located on opposite
sides of the center block 13. As shown in FIGS. 1 and 2, each is
shorter than the full width of the side of the center block 13 and
stops short of the edge to form a shoulder. As illustrated in FIG.
2, the holes 25 begin just in front of the shoulder.
As can be seen from FIG. 1, each hole 25 accommodates one contact
member 16. Each contact member 16 is made from a single piece of
wire such as gold plated phosphor bronze or beryllium copper, and,
as illustrated in FIGS. 2 and 3, is bent into an S-shape so as to
have end sections projecting above the bearing surfaces 19. Because
the contact members 16 pass through the middle of the center block
13, the S-shape is formed after insertion in the holes 25. Since
final forming takes place after insertion in the center block 13,
each contact member 16 can be made merely by inserting the end of a
length of preplated wire into a hole 25 and clipping off the
required segment. Alternatively, the contact members 16 can be
molded into the center block 13. Using either technique, reductions
in manufacturing costs are readily achieved.
In joining two flat cables 14, the cables are first positioned on
the guide pins 21 on the clamp blocks 11 and 12. In the drawing,
the mounting or guide holes in the cables which correspond to the
guide pins 21 have not been shown. They are, however, merely
apertures which pass through the insulating material of the cables
near the conductors 15.
Next, the center block 13 is placed between the cables and clamp
blocks. As can best be understood from FIGS. 2 and 3, two
cable-accommodating spaces or recesses are formed between the
bearing surfaces 18 and 19 as they approach each other.
Lastly, the clamp blocks 11 and 12 are drawn together against the
center block 13 by, for example, driving the bolts 23a into the
nuts 23b. As the clamp blocks 11 and 12 squeeze against the center
block 13, the cables 14 are pressed into the grooves 20 and around
the center block 13. As the cables 14 conform to the contour of the
center block 13, the conductors 15 are pressed against the contact
members 16, thereby establishing an electrical connection between
the conductors in the two cables.
In the completed connector, contact pressure is readily adjustable
without damage to the cables. As can be seen from FIG. 3, the ends
of the contact members 16 project into the spaces or recesses
between the bearing surfaces 18 and 19. Moreover, the surfaces of
the conductors 15 are approximately level with the outer surfaces
of the cables 14. Consequently, engagement of the contact members
16 and the conductors 15 occurs before the bearing surfaces 18 and
19 materially deform the insulating material of the cable 14.
Moreover, the "S" configuration of the contact members 16 permits
the amount of contact force to be adjusted simply by increasing or
decreasing the squeezing force exerted by the clamp blocks 11 and
12. Thus, good electrical contact of readily adjustable magnitude
is readily achieved in a simple manner without detriment to the
cables 14.
In addition, the points of electrical contact between the
conductors 15 and the contact members 16 are protected. When, as
shown in FIG. 3, the clamp blocks 11 and 12 are clamped in the
cable connecting position, the contact members 16 and the exposed
conductors 15 are contained entirely within a protective housing.
Consequently, all essential parts of the connector are protected
from external injury.
Furthermore, cable disconnection and reconnection is quick and
easy. To disconnect, the clamp blocks 11 and 12 are merely
separated and the cables 14 removed from the guide pins 21. To
reconnect, the cables 14 are placed back on the guide pins 21 and
the clamp blocks 11 and 12 are again drawn together to force the
conductors 15 against the contact members 16.
Alternatively, the use of S-shaped contact members facilitates
connection between cables and other electrical apparatus. As shown
in FIG. 4, a number of fixed contacts 27 are embedded in one of the
clamp blocks 11 and 12. Each fixed contact 27 is made of a
gold-plated material such as phosphor bronze, beryllium copper or
brass, and is located so as to be in register with a contact member
16 when the clamp blocks 11 and 12 are positioned against the
center block 13. Thus, when a cable 14 is clamped in place,
electrical paths will extend from the conductors 15 to apparatus,
terminated on the fixed contacts 27.
If desired, contact reliability can be further improved by
modifying the form of the contact members and the center block. As
shown in FIGS. 6 and 7, the contact members 16a are alternatively
formed in an "X" configuration. As before, each is made of a single
piece of wire such as phosphor bronze or beryllium copper and is
preplated with a suitable contact material such as gold before
assembly in the center block 13a. The four legs of each contact
member 16a terminate in four contact points 31; two being closed
and two being open hooks.
In order to accommodate the X-shaped contact members 16a, the slots
24a pass entirely through the center block 13a. Moreover, as shown
in FIG. 6, they taper down to form midpoint shoulders 32 before
flaring out again.
To insert a contact member 16a into the center block 13a, the hook
ends are squeezed together and pushed into a slot 24a. After
insertion, the contact member 16a springs back to its original
shape, but is engaged at its center by the shoulders 32.
As can be seen from FIGS. 5 and 6, the contact points 31 project
upwardly from the center block 13a in order to engage the
conductors 15 in the cables 14 in response to pressure exerted by
the clamp blocks 11a and 12a. Moreover, contact is made serially at
two points on each conductor 15. Consequently, the possibility of a
bad connection between a contact member 16a and a cable conductor
15 is cut in half, thereby insuring improved contact
reliability.
In summary, a connector for use with multiple conductor flat cables
has been disclosed which is reliable in application, simple to make
and easy to use. It is to be understood that the embodiments
disclosed merely exemplify the principles of the invention and many
other embodiments falling within the spirit and scope of the
invention will readily occur to others skilled in the art.
* * * * *