Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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HIGHWAY CABLE CONNE~TOR
~ACKGROUND OF THE INVENTION
The present invention relates to a highway cable
connector for making electrical connection to a
conductor in a length of insulated highway cable at
a point intermediate to the ends of the length of cable.
SUMMARY OF THE INVENTION
According to the invention there is provided a
highway cable connector for making electrical connection
to a conductor in a length of insulated highway cable at
a point intermediate to the ends of the length of cable,
cmprising a pair of interconnected members which are
moveable relative to one another between open and closed
positions, electrically conductive penetrating means
mounted on at least one of said members, said members
being formed to receive the highway cable with the
members in the open position, to present the cable to
said penetrating means and to press the cable against
said penetrating means when the members are moved to the
closed position, whereby on closing the members said
penetrating means penetrates through the insulation of
the cable to make contact with the conductor, wherein
one of said members is a die member formed with a groove
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sized to receive and locate tne cable against transverse
movement relative to the die member, and said
penetrating means comprises at least one electrical
conductive needle point upstanding from the base of the
groove, the other of said members having a ram
positioned to bear against the cable on movement of the
members to the closed position and to press the cable
into the groove and on to the needle point so that the
point pierces the insulation of the cable and makes
connection with the conductor, the pair of members
being hinged to one another about an axis parallel to
the groove and the ram being mounted on said other of
the members such that the ram moves substantially
linearly into the groove at least over a final arc of
relative movement of the members to the closed position.
With this connector, connections can be made inter-
mediate the ends of a length of highway cable without
breaking the cable. This is especially useful when
connecting telephone apparatus to a communication cable
as will become apparent.
In one embodiment providing a connector for making
respective connections to the screen and core
conductors of a co-axial cable, said penetrating means
comprises a first needle point located centrally in the
the groove and having an electrically insulating
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coating except at the tip, and a second needle point
located off-centre in the groove but aligned parallel
to the first needle point, whereby on movement of
said members to the closed position said first needle
point pierces the insulation of the cable and
penetrates through the screen conductor to make
electrical contact only with the core conductor and
said second needle point pierces the insulation and
makes contact only with the screen conductor.
A third needle point may be included corresponding
to and electrically connected to said second needle
point and located off-centre in said groove and
spaced along said groove from said second needle point.
It will be understood that the screen conductor or
co-axial cable commonly includes a loosely braided
conductor structure so that it is theoretically
possible that said second needle point may fail to
make contact with the braided screen conductor of some
co-axial cables. By providing two electrically inter-
connected off-centre needle points, the risk of
failing to make contact w-th the screen conductor is
greatly reduced.
BRIEF DESCRIPTIO~ OF THE DRAWING
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:' Figure l is a side elevation of a highway cable
' 25 connector embodying the present invention; and
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Figure 2 is a view of the connector of Figure 1
taken along arrow X.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figure 1, the illustrated connector has
members 10 and 11 hinged together at pivot 12. The
members 10 and 11 are illustrated in an open position
but are also shown in Figure 1 in ghost in a closed
position.
Member 10 comprises a base in the form of a die
having a transverse groove 13 extending across the width
of the base. The groove has a width selected to
correspond substantially with the diameter of a co-axial
cable forming the highway cable with which the connector
is designed to make connections.
The member 11 is formed as a channel comprising side
flange portions 14 joined by a single elongate web
portion 15. The web portion 15 may be cut away at the
end of the member 11 adjacent the pivot 12 to enable the
member 11 to adopt the open position illustrated in
20 Figure 1. ,
Mounted between the side flanges 14 of the member 11
is a ram 16. The ram 16 comprises a plate-like member
having a thickness corresponding to the width of the
groove 13. A lower end 17 of the ram is machined to
have a cylindrical concave profile so as to match the
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cylindrical profile of the highway cable with which the
connector is to be used. As can be best seen from
Figure 2, the ram 16 extends substantially the full
length of the groove 13.
The ram 16 has a pair of studs 18 on each end face
fitting in corresponding slots 19 provided through the
side flanges 14 of the member 11. A hemispherical stud
20 is fastened midway across the width of the web piece
15 of the member 11, as best seen in Figure 2. The
upper end edge 21 of the ram 16 is machined to have a
cylindrical convex profile as shown in Figure 1. The
slots 19 are arranged to be substantiallyhorizontal
when the member 11 is in the open position as
illustrated in Figure 1, such that the slots 19 are
substantially vertical when the member 11 is in the
fully closed position shown in ghost in Figure 1.
Mounted in the base 22 of the groove 13 are needle
points 23, 24 and 25 (see Figure 2) which are aligned
parallel to the depth and transversely of the length
of the groove. The needle point 23 is located
centrally of the width of the groove and has a length
not substantially greater than half the diameter of
the co-axial highway cable with which the connector is
designed to be used. The needle point 23 is provided
with an electrically insulating coatiny over the major
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part of its length above the base of the groove 13,
except at the tip 26. The insulating coating is
conveniently a thin glazing which may be only a few
microns thick, provded by painting the n~edle with
a glass frit, and then firing the painted needle to
dry off and vitrify the frit as a glass coating on
the surface of the needle point.
The needle points 24 and 25 are uncoated, and are
arranged to be parallel to the needle point 23 but
located off-centre in the groove 13 and spaced apart
one from the other along the length of the groove as
shown in Figure 2. The positioning of the needle
points 24 and 25 relative to the centre line of the
groove 13 is quite critical. It is important that the
needle points 24 and 25 should not be so close to the
centre line of the groove that they can make contact
with the core conductor of the co-axial highway cable
with which the connector is designed to be used. On
the other hand the needle points 24 and 25 should not
be so close to the side of the groove 13 that they
fail to pierce the outer insulation of the co-axial
highway cable sufficiently to make contact with the
screen conductor of the cable.
The needle point 23 is connected via a terminal to
the core conductor 27 of a co-axial cable 28 leading
to the e~uipment whiCh it is desired to connect to
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the highway cable by means o~ the connector. The two
needle pints 24 and 25 are connected together and via
a further terminal to the screen conductor 23 of the
co-axial cable 28.
In operation, the connector illustrated is
presented to the highway cable to which connection is
desired with the member 11 in the open position as
shown in Figure 1, and the highway cable is inserted
in the groove 13. The member ll is then closed by
rotation in the clockwise direction in Figurel
relative to the base member 10 of the connector. This
clockwise closing movement of the member 11 causes the
ram 16 to enter the groove 13 and the concave end face
17 of the ram to bear against the upper surface of the
highway cable in the groove. Continued closing action
of the member 11 causes the ram 16 to press the high-
way cable into the groove so as to be pierced by the
needle points 23, 2~ and 25 until the highway cable is
pressed fully home into the groove and adopts the
position shown in ghost at 30 in Figure 1. In this
position, the needle point 23 penetrates through the
outer insulator of the highway cable and also through
the screen conductor. However, the insulating coating
on the needle point 23 prevents electrical contact
between this needle point and the screen conductor of
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the highway cable. The uninsulated tip 26 of the
needle point however makes electrical contact with the
core conductor of the highway cable as illustrated in
Figure 1. The two off-centre needle points 24 and 25
penetrate through the outer insulation of the highway
cable and at least one of them normally makes contact
with the braided screen conductor of the cable. Thus,
electrical contact is made to the core and screen
conductor respectively of the highway cable without
breaking the cable.
On closing the member 11, it can be seen that the
hemispherical stud 20 bears against the convex
cylindrical end 21 of the ram 16. The slots 19 in the
side flanges 14 of the member 11 permit the ram 16 to
move angularly relative to the member 11 so that the
ram 16 can adopt a purely linear motion down into the
groove 13 at least over the final arc of the closing
movement of the member 11. The outer edge of the
groove 13 on the side of the groove adjacent the pivot
12 is rounded off in a circular profile as illustrated
in Figure 1 so as to permit the ram 16 to slide over
this edge into the groove during the closing movement
of member 11.
In order to keep the connector fimly closed and
maintain good connection with the highway cable, a
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spring clip 31 is provided fa6tened to the base member
10 of the connector and arranged to clip over an outer
end 32 of the member 11 when in the fully closed
position.
