U.S. patent number 3,594,704 [Application Number 04/863,132] was granted by the patent office on 1971-07-20 for in-line connector for electrical conductors or the like.
This patent grant is currently assigned to Raychem Corporation. Invention is credited to Christopher L. Fischer.
United States Patent |
3,594,704 |
Fischer |
July 20, 1971 |
IN-LINE CONNECTOR FOR ELECTRICAL CONDUCTORS OR THE LIKE
Abstract
A connector for making an in-line electrical connection between
two or more insulated electrical wires or conductors in which a
pair of spaced teeth on an upper jaw member cooperate with a tooth
positioned on a lower jaw member such that meshing of the teeth
cause the conductors to be bent around the lower tooth and the
insulation to be stripped therefrom along planes parallel to the
planes of movement of the teeth.
Inventors: |
Fischer; Christopher L.
(Sunnyvale, CA) |
Assignee: |
Raychem Corporation (Menlo
Park, CA)
|
Family
ID: |
25340342 |
Appl.
No.: |
04/863,132 |
Filed: |
October 2, 1969 |
Current U.S.
Class: |
439/421 |
Current CPC
Class: |
H01R
4/2495 (20130101) |
Current International
Class: |
H01R
4/24 (20060101); H01r 011/20 () |
Field of
Search: |
;339/95,97--99,223 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Champion; Marvin A.
Assistant Examiner: McGlynn; Joseph H.
Claims
I claim:
1. A connector for electrical wires or the like having an external
sheath of insulating material comprising:
a base, said base having a lower jaw member positioned thereon and
protruding above the surface thereof;
first and second upper jaw members formed integrally with said base
and extending above said base to form a generally C-shaped article
for receiving said wires between said upper and lower jaw members,
said upper jaw members being deformable to permit movement thereof
toward said base;
said first and second upper jaw members being laterally displaced
from said lower jaw member by a distance slightly less than the
diameter of said wires less said external sheath so that each of
said upper jaw members form with said lower jaw member a pair of
laterally displaced parallel shear planes;
movement of said upper jaw members toward said base causing said
wires to be deformed about said lower jaw member to position said
wires such that portions of the external sheath of each wire is
parallel to said shear planes whereby said jaw members remove said
sheath from said portions of said wires in a direction parallel to
the axes of said wires, said base limiting the relative movement of
said jaw members and preventing shearing of said wires in a
direction normal to their axes.
2. The connector of claim 1 wherein said jaw members have inwardly
extending ends.
3. The connector of claim 1 wherein said base is provided with
serrations on either side of said lower jaw member.
Description
BACKGROUND OF THE INVENTION
The need for devices capable of connecting two or more electrical
conductors is of long standing and consequently many connectors
have been proposed and used for this purpose. Of particular
desirability in many applications is a connector which can be
installed in line, that is, at some point intermediate the ends of
the conductors and without the necessity of either sliding the
connector over the wires from their ends or stripping the
insulation off of the wires back to a point where the connection
will be made. An example of an application where such a device
would be particularly useful is in the interconnection or splicing
of several wires in a telephone cable of the type which typically
may contain several thousand of such insulated conductors.
The devices which have been most commonly proposed for this purpose
are crimped onto the wires, that is, the connector is provided in
some fashion with teeth or other objects suitable for piercing the
insulation, and the connector is deformed over the wires to cause
the teeth to pierce the insulation and make electrical contact with
the conductors themselves. A typical example of such a crimped
device is disclosed in the U.S. Pat. No. 2,783,447 to Watts.
As shown in the Watts patent, a generally U-shaped metal member is
provided with slots and corresponding shear blocks which are caused
to shear the conductors in a direction perpendicular to the axis of
the conductor, that is, the shear planes are so arranged that a
portion of the wire is actually laterally displaced, the remaining
exposed portions of the conductor making electrical contact with
the connector to form the electrical connection. As disclosed in
Watts, the connector is installed on the wires by use of a special
crimping tool which causes the arms of a U-shaped member to be bent
inwardly and over, and the connector to be deformed so that the
shear blocks enter their associated slots and cause the lateral
displacement of a portion of the conductor. While such connectors
are generally satisfactory, they have several disadvantages. First,
a special crimping tool is required for their installation and
these tools are relatively expensive. Moreover, since different
size connectors are needed for different size wires, different size
crimping tools are also often needed, requiring an extensive
inventory of both connectors and tools. In addition, the connectors
themselves are relatively large and consequently expensive. Perhaps
more seriously, the operation of this type connector often causes
the wires to be completely severed or at least so weakened by the
shearing action which takes place that they no longer have the
desired mechanical stability and may in time separate at the
shearing planes to the detriment of both the mechanical and
electrical connection.
Another typical connector used for somewhat the same purpose is
shown in the U.S. Pat. No. 2,965,699. to Bollmeier. In the
Bollmeier patent there is disclosed a generally tubular connector
in which a first plurality of bars cooperate with a second
plurality of bars to bend the wires into a serpentine shape and
sever them. The spacing between the bars is progressively greater
and this spacing is maintained by widened tips provided on the ends
of the bars of the second plurality. The construction of the
Bollmeier device requires that it be passed over the ends of the
wires. However, this is no particular disadvantage for his purposes
as he wishes to sever the ends of the wires in any event. As in the
Watts patent, the Bollmeier structure provides no means for
limiting the movement of the cooperating bars of the conductor so
that an excess force can cause these bars to move sufficiently
relative to each other to sever the wires. However, as already
noted, this is one of the purposes of the device and thus prevents
no overwhelming obstacle to the use of the device. However, for
these reasons, the device would be less than satisfactory as an
in-line device. The device is also rather large and expensive to
construct.
SUMMARY OF THE INVENTION
According to the present invention, a connector is provided which
can be installed in-line with a simple tool such as a pair of
pliers without fear of severing the wires to be connected. This is
accomplished by providing the connectors with jaws formed to bend
the conductors and scrape off the insulation in a direction
parallel to the axis of the wires. In this manner the wires
themselves are not subjected to any substantial shearing forces and
their cross-sectional areas are not significantly reduced. In
addition, the shearing of the insulation in this manner causes the
jaws to make a wiping contact with the conductive portions of the
wires it being recognized in the art that a wiping contact of this
type is most desirable from an electrical standpoint. The connector
is formed so that the jaws are integral and one jaw has a base
which acts as a stop for the cooperating jaw, that is, it prevents
relative movement of the jaws to a point where the wires could be
severed. The connector is very simple and inexpensive to
manufacture, is quite small, and can be quickly and easily
installed with a simple tool thereby obviating the necessity for a
number of expensive special tools.
It is therefore an object of the present invention to provide a
connector for electrical wires or the like which is relatively
inexpensive and which can easily be installed intermediate the ends
of the wires without substantial danger to the mechanical integrity
of the wires.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the connector of the present
invention;
FIG. 2 is an end view of the connector of the present
invention;
FIG. 3 is a top plan view of the connector of the present
invention;
FIG. 4 is a front elevation view of the connector of the present
invention; and
FIG. 5 is a cross-sectional view of the connector of the present
invention showing it installed on a pair of electrical wires.
DESCRIPTION OF THE INVENTION
As shown in the several FIGS. the connector 10 of the present
invention includes a base 12 having serrated portions 13 and 14 on
its upper surface, the serrated portions 13 and 14 being separated
by a flat portion 15. Extending upwardly from the base 12, and
integral therewith, are jaw portions 16 ans 17 which extend
outwardly over the base 12, generally overlying the serrated
portions 13 and 14, so that the connector 10 is generally C-shaped
in cross section.
Intermediate the jaw portions 16 and 17 is a slot 18 formed by
punching out a lower jaw portion 19 which is bent over to engage
the flat region 15 of the base 12. If desired, the jaw portion 19
can be bonded to the flat region 15 but such is not generally
necessary. As can best be seen in FIGS. 3 and 4, strips of material
are removed from the sheet of metal from which the connector is
formed to leave slots 20 and 21 between the jaw portions 16 and 17
and the lower jaw portion 19. These strips are preferably removed
as part of the same punching operation which forms the jaw
portions, and are of a width consistent with the wire size to be
used as explained more fully hereinafter. Preferably, the outer
ends 22 and 23 of the upper jaw portions 16 and 17 are bent
downwardly and the outer end 24 of the lower jaw portion 19 is bent
upwardly so that upon closure of connector the wires held therein
cannot escape through the open side of the connector. Preferably,
the ends of the upper jaw pieces and the base are chamfered as
shown at 26, 27, 28 and 29 to prevent sharp bending or nicking of
the conductor.
To install the connector 10, the wires to be connected are
positioned over the lower jaw portion 19 within the upturned end 24
thereof. A pair of pliers or another suitable tool is then used to
force the upper jaw portions 16 and 27 down toward the base 12 and
lower jaw portion 19. When the upper jaw portion 16 an 17 engage
the wires or conductors 30 (only one of which can be seen in FIG.
5) positioned within the connector, they cause the conductors to be
bent around the lower jaw portion 19 with the wires fitting into
the slots 20 and 21 as shown in FIG. 5. At the same time, and as
downward pressure of the upper jaw portions 16 an 17 continues, the
scissorlike action of the jaw edges 31 and 32 and 33 and 34 will
scrape or shear the insulation 35 from the wires 30 exposing the
conductive portions 36. Movement of these edges will also case the
continued deformation of the conductors into the slots 20 and 21.
The width of the slots 20 and 21 is made slightly smaller than the
diameter of the conductive portion 36 so that the action of the jaw
edges causes the exposure of fresh unoxidized metal on the
conductor as well as the removal of the insulation therefrom,
thereby providing the desired sliding contact. It should be
understood that one or more conductors may be inserted into each
end of the connector, the heretofore described operation of the
connector making good electrical connection between all of
them.
As can be seen, the base 12 acts as a stop which limits the
relative movement of the upper and lower jaw portions and prevents
an appreciable shearing force to be exerted on the wires in a
direction normal to their axis. Consequently, the wires are not
subjected to a substantial reduction of their cross-sectional area
nor any other attack on their mechanical integrity. The serrations
of the portions 13 and 14 serve the purpose of locating the
conductors securely between the closed jaw surfaces and prevent the
conductors from flexing at their weakest points, that is, the areas
of deformation or bending. In addition, the clamping force of the
jaws acts as a strain and tension relief on the conductors.
* * * * *