Note: Descriptions are shown in the official language in which they were submitted.
MP1239 COM-CA
- ~LZ9138~31S
Telecommunications Terminal Block and AdaPter
Field of the Invention
This invention relates primarily to telecommunications
terminal blocks by means of which multi-core cables, often
containing many tens or hundreds of conductor pairs, may be
terminated for final connection to drop wires that lead to
individual subscriber's telephones, and for convenience will
be described in such terms. The invention may, however, be
useful for making other similar electrical connections.
Backqround of the Invention
Various types of terminal blocks have been used in the
telecommunications industry which provide some means for
anchoring an incoming multi-core cable and which have a
number of pairs o~ conductors, known as binding posts, to a
base of each of which a conductor oE the cable is more or
less permanently connected. A top part of each binding post
protrudes above an uppar surface of the block, and is screw-
threaded. A stripped drop wire may be wrapped around the
exposed binding post and secured with a washer and nut, thus
making a breakable electrical connection between a core of
the incoming cable and the drop wire. A terminal block may
typically provide Eor connections to up to 25 pairs oE con~
ductors, a pair of conductors of course being required for
each telephone.
Several problems may arise with such terminal blocks, in
particular corrosion. The binding post~, washer and nuts,
~, .
~ 5 MP1~39-CCM
and drop wires are liable to corrosion and other environmen-
tal damage which results in interference and cross-talk etc.
on telephone lines. Provision of a permanent seal around
the binding posts or around the whole block is generally
not practical since access to the conductors for testing of
the lines or for rearrangement of the lines may be required.
An excellent re-enterable technique for encapsulation of
binding posts is marketed by Raychem under the trademark
Termseal, and is di.sclosed in U.S. ~,634,207.
This tech-
nique generally requires however, that badly corroded
binding posts be properly cleaned and that new washers and
nuts be employed before the technique is carried out. That
may not always be convenient or possible to ensure.
A ~urther problem is inherent in the design o prior art
terminal blocks, in that they require that the drop wires be
pre-stripped at their ends before connection to the binding
posts. Also, in the case of multi-core drop wires
(generally two cores side-by-side, giving the drop wire an
oval or almost rectangular cross-section), the drop wire has
to be split, i.e. its cores separated for separate connec-
tion to spaced-apart binding posts. Thus the wire is split
in two, and insulation removed from each of the resulting
two wires, and connection then made to the binding posts,
after cleaning in the case of repair to an installed block.
The present invention is able to overcome such problems
as these by providing an article and a method whereby a non-
stripped, non-split, multi-core drop wire can be connected
to an existing, prior art terminal block (an exercise that
may be referred to as rehabilitation) and preferably to ter-
minal blocks of dif~erent binding post separation. The
invention also provides a new terminal block whereby such
multi-core drop wires may be connected to a multi-core tele-
communications cable.
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Summary of_the Invention
The present invention therefore provides an adapter by
means of which cores of a multi-core drop wire can be con-
nected to a pair of ~inding posts of a terminal block, which
comprises:
(a) two caps that can be received on respective binding
posts; and
(b) a housing having:
(i) two first apertures each extending from a
first surface to a second surface of the
housing, the housing being positionable with
the first surface adjacent the terminal block
and the binding posts within respective said
first apertures such that the posts can
receive respective caps at the second sur-
face, the caps extending within respective
said first apertures; and
(ii) a second aperture that passes between, and is
in communication with each of, said first
apertures, the second aperture being capable
of receiving said drop wire such that respec-
tive cores thereof pass through respective
first apertures and are contacted by respec-
tive caps when received by respective binding
posts within the first apertures.
~ he invention also provides a terminal block by means of
which conductors of a multi-core cable can be connected to
the cores of at least two multi-core drop wires, which
comprises a housing having:
(a) a first pair of binding posts, to respective posts
of which respective cores of a first said drop wire
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can be connected, each post having means for con-
nection to a conductor of said ca~le;
(b) a second pair of binding posts, to respective posts
of which respective cores of a second said drop wire
can be connected, each post having means for con-
nection to a conductor o~ said cable;
each binding post being capable of receiving a
cap, such that when the cap is received by a
binding post and over said drop wire adjacent
the binding post contact is made to a core of
the drop wire;
(c) a first aperture that passes between binding posts
of the first pair, the aperture being capable of
receiving a first said drop wire such that respec-
tive cores of the drop wire are adjacent respective
binding posts of the first pair and can be indivi-
dually contacted by caps thereon; and
(d) a second aperture that passes between binding
posts of the second pair, the aperture being
capable of receiving a second said drop wire such
that respective cores of the drop wire are adjacent
respective binding posts of the second pair and can
be individually contac-ted by caps thereon.
The invention further provides a method of connecting a
multi-core drop wire to a terminal block having a pair of
binding posts, by means of an adapter comprising two caps
and a housing, the housing having:
(i) two first apertures each extending from a first
surface to a second surface of the housing; and
(ii) a second aperture that passes between, and is in
communication with each of, said first apertures,
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the second aperture being capable of receiving said
drop wire such that respective cores thereof pass
through respective first apertures;
which method comprises:
(A) positioning the housing on the terminal block with
the first surface adjacent the bloc~ and the
binding posts within respective said first aper-
tures;
(B) positioning the drop wire within the second aper-
ture; and
(C) positioning the caps on respective binding posts at
the second surface such that the caps extend within
respective said first apertures and contact respec-
tive cores of the drop wire.
The invention further provides a terminal block by means
of which a conductor of a multi-core cable can be connected
to the core of a drop wire, which comprises a housing
having:
(a) a terminal to which the core of said drop wire can
be connected, the terminal having means for connec-
tion to a conductor of said cable;
the terminal having a female screw-thread and
being capable of receiving a cap having a male
screw-thread, such that when the cap is
received by the terminal and over said drop
wire adjacent the terminal contact is made to
a core of the drop wire;
(b) a first aperture that passes adjacent the terminal,
the aperture being capable of receiving said drop
~ire; and
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c) said cap having a male thread and that can be
received by the terminal.
The invention further provides a cap suitable for use on
a terminal block housing for connecting an insulated drop-
wire to a terminal of the housing, which cap comprises:
(a) a body having a male screw-thread;
(b) a recess around the screw-thread;
(c) a sealing material in the recess;
(d) an insulation-dlsplacement cutting edge around the
screw-thread.
The invention further provides a terminal block by means
of which conductors of a multi-core cable can be connected
to the cores of a multi-core drop wire, which comprises a
housing having:
(a) a pair of binding posts, to respective posts of
which respective cores of a first said drop wire
can be connected, each post having means for con-
nection to a conductor of said cable;
each binding post having a female screw-thread
and being capable of receiving a cap having
male screw-thread, such that when the cap is
received by a binding post and over said drop
wire adjacent the binding post contact is made
to a core of the drop wire;
tb) an aperture that passes between the binding posts,
the aperture being capable of receiving said drop
wire such that respective cores of the drop wire
are adjacent respective binding posts of -the ~irst
pair and can be individually contacted by caps
thereon.
_7 ~8~ MP1~39-COM
The invention also provides an adapter that may be used
over ~inding posts of different separation, and thus an
adjustable or variable adapter is provided.
Thus, the invention further provides an adapter
as defined above, in which the housiny comprises first
and second parts;
the first part having therein one of said first aper-
tures and a portion of said second aperture;
the second part having therein another of said first
apertures and another portion of said second aperture;
the first part being moveable relative to the second
part.
The invention still further provides an adapter by means
of which cores of a multi-core drop wire can be connected to
a pair of binding posts of a terminal block, which
comprises:
a housing having:
(i~ two first apertures extending from a first surface
to a second surface of the housing, the housing being
positionable with the first surface adjacent the ter-
minal block and the binding posts within respective said
first apertures; and
(ii) a second aperture that passes between, and is in
communication with each of, said first apertures, the
second aperture being capable of receiving said drop
wire such that respective cores thereof pass through
respective first apertures;
the housing comprising ~irst and second parts;
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the first part having therein one of said first aper-
tures and a portion of said second aperture;
the second part having therein another of said first
apertures and another portion of said second aperture;
the first part being connected to and movable relative
to the second part from a first relative position to a
second relative position in each of which relative position
axes of the two first apertures are substantially mutually
parallel, and axes of said portion and of said other portion
of the second aperture are substantially mutually parallel.
The invention yet further provides an adapter by means
of which a core of a multicore dropwire can be connected to
a binding post of a terminal block, which comprises:
a housing having:
(i) a first aperture extending from a first surface to
a second surface of the housing, the housing being posi-
tionable with the first surface adjacent the terminal
block and the binding post within the first aperture;
and
tii) a second aperture that passes adjacent, and is
incommunication with, said first aperture the second
aperture being of non-circular cross-section and
breaking into the first aperture to such an extent that
less than 67% (preferably less than 50%) of a transverse
dimension of the second aperture lies within the first
aperture.
~The words "first" and "second" in the context, for example,
of first and second apertures are mere labels and do not
imply a difference in shape etc. The second aperture of the
adapter is in fact, generally equivalent to the first aper-
ture of the terminal block.)
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The term "binding post" will be readily understood by
those skilled in the art. The term means a terminal,
~enerally small and screw threaded, used to ma~e electrical
connections to wires. Usually a binding post is part of a
terminal block. Prior art binding posts have a male screw-
thread, i.e. have the form of bolts, and nuts are screwed
over them to secure wires for electrical connection. In the
present invention caps, (having a female screw-thread, i.e.
having the form of nuts but optionally also having for
example insulation-displacement means or recesses for
holding sealing material) may be used on such binding posts.
As will be clear from the text, the term "binding post" (and
the term "terminal") is used herein also to include a con-
nection means that has a female screw-thread (i.e. has the
form of a nut) and into which a cap, having the form of a
bolt, may be screwedO This type of binding post (see figure
8) may be mounted in a hole in a terminal block, for use
with a cap such as that shown in figure 9.
Detailed Description of the Invention
The housing of the adapter of the invention preferably
comprises a block of insulating, generally plastics, material
whose first and second surfaces are substantially planar
(but may have recesses in them for receiving sealing
material etc.) and are mutually parallel. The first and
second surfaces will generally have a major dimension of
2-10, especially 3-6 cm, and a minor dimension of 1-5, espe-
cially 1.5-3 cm. The separation between the first and
second surfaces, i.e. the thickness of the block, is pre-
ferably 0.5-3, especially 0.75-1.5 cm. Where the adapter is
used for rehabilitation of terminal blocks such as Western
Electric 9Al or TII Model 325 the block is preferably about
2.5 ~ 4 cm by 1.0 cm thick. Several such blocks can be
positioned side-by-side over several pairs of binding posts,
the pairs being about 2.5 cm apart, and the posts of each
pair about 2.2 cm apart.
9.~9~89S
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The housing may be specially shaped such that two or
more can be positioned side-by-side in substantially close
packing arrangement: its first and second surfaces may be
thought of being rectangular with one or more corners
removed to allow this close-packing, bearing in mind that a
stiff drop wire emerging from the second aperture rnay have
to be accommodated. The housing may therefore have first
and second sides that e~tend between the first and second
surfaces, the drop wire emerging, say, from an opening in
the second side. The first side will then preferably have a
substantially similar shape (at least as seen in plan view
oE the housing) to the combined shape of the second side
plus a substantially straight drop wire extending therefrom.
The second aperture is preferably straight since the
drop wire may be stiff, and thus difficult to insert into a
cur~ed aperture, particularly if, as is preferred, the drop
wire is a close fit in the aperture. The aperture is pre-
ferably elongate and closed in transverse cross-section
(although it may, for example, comprise an open channel).
This is because such an aperture may be better able to
locate the drop wire with respect to the first apertures and
therefore to the binding posts for proper contact with the
caps. We prefer that the second aperture is of non-circular
cross-section such that the cores of a multi-core drop wire
therein of non-circular cross-section are maintained in
fixed orientation with respect to the first apertures, and
therefore to the binding posts.
The first apertures are preferably each of closed, more
preferably circular, cross-section. ~ach first aperture may
be of smaller diameter (preferably substantially equal to
that of a binding post) at the first surface, and of larger
diameter at the second surface. That larger diameter is
preferably substantially equal to the diameter of a part of
the cap that the aperture will receive when the cap is posi-
8~5
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tioned on the binding post when received by the aperture.
The aperture is thus stepped, and the transition from larger
to smaller diameter limits the extent to which the cap is
received on the binding postt and thus may prevent damage to
the underlying drop wire. Other means may, however, be pro-
vided for limiting travel of the cap on the binding past,
for example a closed end of the cap may ground on the top of
the post.
The caps preferably include insulation displacement
means, for example a cutting bottom edge. Thus, as they are
brought down over the binding posts they cut into the insu-
lation of the underlying drop wire. It is desirable that
they cut through the insulation, and cannot be advanced suf-
ficiently further that they excessively damage the cores of
the drop wire. Hence, the preferred means for limiting tra-
vel mentioned above. Thus, the second aperture may break
into the first aperture at the above-mentioned transition of
diameters, such that a core of a drop wire in the second
aperture lies predominately in the part of smaller diameter
whereas the insulation to be displaced lies in the part of
larger diameter and is therefore accessible to the insula-
tion displacement edge of the cap.
The binding posts and caps are preferably screw-
threaded, so that caps are simply screw-threaded down onto
the posts. The insulation means its then preferably an
annular cutting edge, that overlaps one core, but not both
cores, of the drop wire. The second aperture may therefore
pass obliquely between two binding posts such that one edge
of a drop wire therein lies adjacent one post and the oppo-
site edge lies adjacent the other post. When the caps are
screwed down over the posts, one cuts into one half of the
drop wire, and the other into the other half, thus making
contact to the cores. We prefer that slackening-off of the
caps results in breaking of contact to the cores, par-
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ticularly without complete removal o~ the caps. This allows
independent testing of a circuit from the terminal block
back to the central office, or on to the subscri~er by
selective slacKening-off of one of the caps from a pair of
~inding posts.
A sealing material may be provided that encapsulates the
binding posts, caps and/or drop wires to provide further
environmental sealing, although the need for such sealing
material may be reduced in the present invention since the
vulnerable surfaces and the connections to be made may be
buried within the housingO
A preferred sealing material comprises a gel, for
example based on polyurethane or silicone. As an example a
material may be mentioned that is made by gelling curable
polyurethane precursor materials in the presence of substan-
tial quantities of mineral oil, vegetable oil or pLasticizer
or a mixture of two or more of them. Also, a suitable
material may be made by curing reactive silicones with non-
reactive extender silicones. The material may contain addi-
tives such as moisture scavengers (e.g. benzoyl chloride),
antioxidants, pigments and fungicides. The material is pre-
ferably electrically-insulating and hydrolytically-stable.
We prefer that the sealing material have a cone penetra-
tion value as measured by ASTM D217-6a at 21C of 100-350
(1~-1 mm), more preferably 150-350, especially 200-300 (10~
mm). Cone penetration is measured on an undisturbed sample
using a standard l:l scale cone (cone weight 102.5 g, shaft
weight 47.5 g) the penetration being measured after 5
seconds. The material preferably has an ultimate elongation
as measured by ASTM D638-80 at 21C of at least 200%, pre-
ferably at least 500%, especially at least 750-~. In the
measurement of elongation, a Type 4 die is used to cut the
sample, and elongation is measured at 50 cm per minute. We
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have found that with such materials it is possible to pro-
vide excellent encapsulation of the binding posts, caps
and/or drop wlres etc., particularly if the material is
maintained under compression around them, but that it can be
substantially cleanly removed from them for inspection or
repair etcO Such sealing material may be provided within
the caps, or within recesses in the housing.
The terminal block of the invention may incorporate any
of the relevant features described above in connection with
the adapter. In general, the terminal block will comprise a
housing having at least 2 pairs, preferably 2-25, more pre-
ferably 2-10, especially 5 or 6 pairs of binding posts.
Each pair of binding posts will have associated with it an
aperture that can receive a drop wire as described above.
The terminal block may have means, such as a recess, for
accommodation of an end of a multi-core cable, and may have
means for providing strain relief to the cable. It may be
housed in an enclosure.
Brief Description of the Drawings
Figure l shows a prior art terminal bloc~;
Figure 2 shows an adapter of the invention used for
rehabilitation of a prior art terminal block;
Figure 3 shows a terminal block housing of the inven-
tion;
Figure 4 is a plan view of a preferred adapter housing,
together with a drop wire;
Figures 5A and 5B are views of terminal blocks, fitted
with adapters and drop wires;
Figure 6 is a section through a partially assembled
adapter of the invention;
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Figure 7 shows a holdi.ng means that may be used with two
single core ~rop wires, for insertion into the adap'cer;
Figure 8 shows a terminal ~lock; and
Figure 9A and 9B show caps for the terminal block of
figure 8.
Figure 10-13 show an adapter that can be adjusted to
suit different binding post separations.
Figure 1 shows a prior art terminal block 1 comprising a
housing 2 carrying five pairs of binding posts 3. A drop
wire 4 is shown connected to a binding post by means of
washers 5 and a nut ~.
An adapter 7 of the invention is shown in figure 2, in
position ready to be placed over binding posts 3 of a prior
art terminal block housing 2. The adapter 7 comprises a
housing 8 and caps 9. The housing 8 has two first apertures
10 extending from a first surface 11, which will lie adja-
cent the terminal block, to a second surface 12. The first
apertures have greater size 13 at the second surface 12, and
smaller size 14 at the first surface 11. The greater size
13 is for accommodation of a part 15 of the caps 9, and the
smaller size 14 is for accommodation of the binding posts 3.
A second aperture 16 passes between, and is in communication
with each of, the first apertures. A multi-core drop wire
may be positioned in the second aperture, such that respec-
tive cores of the drop wire pass through respective first
apertures. Thus, when the caps 9 are positioned over the
binding posts, parts 15 thereof will contact the respective
cores, if necessary after f irst passing through the drop
wire insulation. The second aperture preferably breaks into
the first aperture to such an extent that less than 67%
(more preferably less than 50%) of a transverse domension of
the second aperture lies within the first aperture. In this
12988~S
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way only one core of a two core drop wire will lie within
any given first aperture and be capable of being contacted
by any given cap.
The adapter may have more than two first apertures, and
may have more than one second aperture.
The adapter may be used in conjunction with means for
providing electrical protection to the circuits to be con-
nected, for example against lightning strikes. ~uch pro-
tection may comprise a block that is first positioned over
the binding posts, and which has its own binding posts over
which the adapter is in turn positioned. The protection may
operate by switching high voltages to ground.
A terminal block 2 of the invention is shown in figure
3. This block 2 may be regarded as similar to a series of
adapters having binding posts 3 fixed thereto. A first ter-
minal block aperture 17 can be seen to pass between the
binding posts 3, and is capable of receiving a multi-core
drop wire such that respective cores thereof are adjacent
respective binding posts. Reference to the first aperture
passing between the binding posts is to be taken to include
a situation where the binding posts stop short of the level
in the block of the aperture, or in other words where the
aperture is above (as drawn) the tops of the binding posts.
In this case the caps may have threaded portion that extend
down below a part that engage the drop wire in order to meet
the binding posts. The situation illustrated (namely where
the aperture lies between the top and the bottom of each
post) will be preferred where the binding posts have the
Eorm of bolts, and the caps have the form of nuts. Where,
however, the binding posts have the form of nuts and the
caps have the form of bolts, the aperture will preferably be
positioned above the tops of the binding posts. The ter-
minal block preferably has from 2-25 pairs of binding posts,
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only one pair being shown. The conductors of a multi-core
cable to be connected to drop wires may be connected ko the
binding posts in any suitable way, for example by soldering
to their bases.
Figure 4 is a plan view of a preferred adapter housing
12 of the invention. The two parts 13, 14 of the first
apertures can be seen, as can the path of the second aper-
ture 16. A multi-core drop wire 18, having two conductor
cores 19, is shown ready to be slid into the aperture 16.
The adapter housing 12 is shaped in figure 4 to provide a
better fit when several such housings are placed side-by-
side on a terminal block. This is shown in figure 5.
In figure 5A, five adapter housings 7 are positioned
over five pairs of binding posts 3 on a terminal block
housing 2. The left hand adapter housing 7 is shown with
caps 9 in place. Drop wires 18 are shown extending into the
adapter housings, and the housings can be seen to be shaped
to allow a substantially close packing arrangement, their
lower left-hand corners cut-away to accommodate drop wires
of adjacent housings. Thus, first side 20 of each terminal
block has a substantially similar shape to the combined
shape of a second side 21 plus a substantially straight drop
wire 18 extending therefrom.
The design of figure 5B is similar to that of figure 5A,
but the binding posts of each pair are staggered along the
length of the block. This allows the drop wires to leave
the adaptors on the block in a direction substantially per-
pendicular to the long sides of the block. A close-packing
arrangement of the adaptors may still be achieved.
Figure 6 is a partial section through a part of an
adapter having a drop wire 18 inserted therein, and posi-
tioned over a terminal block housing 2 and binding posts 3.
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The dro~ wire 18 can be seen within aperture 17 and passing
behind the left-hand binding post 3 such that core 19A will
be contacted by cap 9 when screwed down over that binding
post. The drop wire 17 then passes out oE the sec~ion in
front of, and adjacent the right-hand binding post. Core
l9B will be contacted by a cap on that binding post.
The cap 9 can be seen to have an internal screw thread,
which engages screw threads of the binding post 3. The cap
also has a part 15 that will extend into an upper part 13 of
the first aperture, a base of the part 15 having an insula-
tion displacement cutting edge 22 that cuts through insula-
tion of the drop wire to contact a core thereof. The
cutting edge 22 is prevented from severing a core by its
grounding on the base 13A of the wide upper part 13 of the
first aperture. The cap may be provided with a sealing
material such as a gel, preferably in the form of a collar
23.
The adapter housing may have a recess 24 within which
may be positioned a sealing material such as a gel, again
preferably in the form of a collar 25. When the caps are
tightened down onto the binding posts, the adapter housing
is forced against the terminal block housing 2, thus causing
the sealing material to be displaced around the surfaces of
the binding posts, cap and drop wire. The sealing material
may be retained under compression by some means for example
by the extent to which the cap is tightened on the binding
post. When the cap is in position it can be seen to make
electrical connection from the core of the drop wire to the
binding post, which in turn may be connected to a conductor
of a multi-core telecommunications cable. The contact bet-
ween the cap and the core may be maintained by some resi-
lient bias, for example that provided by compression of the
insulation of the drop wire under the core, or by other
means.
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The adapter and terminal block of the invention may be
used with stripped multi-core drop wires or with pairs of
single core drop wires. If desired, some means may be pro-
vided to hold two such single core drop wires in proper
position relative to one another, for example by providing
some holding means that may be folded around the pair or
into which the pair may be slid. In this way, a multi-core
drop wire may be said to be formed from single core wires.
The insulation-displacing caps may then cut through this
holding means in the same way that it cuts through the insu-
lation of a two-core drop wire. We prefer that this holding
means can be folded around the pair and that two parts of it
can snap together, optionally causing the drop wires to be
cut to length. A holding means 26 is illustrated, together
with a pair of drop wires 27 in figure 7~ It may have a
live hinge 28, means 29 for loc~ing it closed, cutting means
30 for cutting the wires 27 to length, and means 31 for
locating the wires.
Figure 8 shows a novel terminal block 2 having female
screw-threaded binding posts 31. The caps 9 have male
screw-threads 32, which can be screwed into -the binding posts
31. The caps may also have an insulation-displacement
cutting edge 22. Drop wires 18 are shown entering apertures
17. The conductors of a multi-core cable 33 may be con-
nected to the posts 31 at the base of the block 2. The
binding posts 31 may lie flush with bases of apertures 10 in
which case the threads 32 will extend below edges 22 of the
caps. Alternatively, the pos-ts 31 may extend above the
bases of the apertures lO (as drawn), in which case the
threads 32 need not extend below edges 22. Drop wire guide
or support means 34 are also shown.
Figures 9A and 9B show, in partial section, a preferred
cap 9 having male screw-threads 32. The cap has an insula-
tion cutting edge 22 and a sealing material 23. The block
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(or adapter) with which such caps are used need be provided
with no sealing material, since where desired it can be
supplied in the caps. Thus, if sealing material becomes
ineffective or partially lost, a new cap, pre-filled with
sealing material, can be used. The cap may be provided with
means 35, for example as a screw-threaded or other plug,
that can make and break electrical connection between the
external screw threads 32 and the insulation cutter 22.
Thus, in the configura-tion of figures 9A the means 35 is
partially removed thus breaking connection between threads
32 and cutter 22, thus breaking connection between the
multi-core cable and the drop wire. In figure 9B the means
35 is screwed home, thus making the connection. This make
and break capability may be useful for selective testing of
different parts of a telephone circuit employing a ter~inal
block of the invention. Alternatively, breaking of the con-
tact may require slight unscrewing of the cap 9, the means
35 being provided merely to cover a hole in the cap, which
hole may serve to provide a contact point for a testing
probe.
Figures 10-13 illustrate adapters having a variable
separation between first aperture thereof. Such an adapter
preferably has two first apertures but may have more.
Figure 10 illustrates in disassembled form an adapter
comprising a housing 8 having two parts, a first part 8A at
the left-hand side of the figure and a second part 8B at the
right hand side of the Figure. One first aperture 10 runs
through the first part 8A and a second first aperture 10
runs through the second part 8B. Each of the first and
second parts 8A, 8B comprises a base 36 and a wire-holder
37. A portion 16A of the second aperture lies in the wire
holder 37 of the first part 8A and another portion 16B lies
within the wire-holder 37 of the second part 8B. Generally,
the second aperture will extend right through one of the
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wire holders, and be blind in the other wire holder. l'he
second aperture is preferably of non~circular, generally
substantially rectangular or oval, cross-section for close-
fitting receipt of a multi-core drop-wire 1~. The base of
the first part may be unconnec~ed to that of the second
part, but we prefer that they be connected together, ~or
example slidably connected together. One technique of sli-
dable connection comprises telescoping of the first and
second parts together, for example by telescoping of pins 38
mounted on one base into apertures in the other base.
Sliding, or other movement of one base tor part in general)
relative to the other results in a change in the separation
between the two first apertures 10. Thus, a given adapter
may be used on design of terminal block having different
separations between its binding posts.
When the bases 3B are moved towards or away from each
other it will in general be necessary that the wire-holders
37 be able to rotate, and preferably each is each of a pair
is able to be angularly rotated about an axis of a respec-
tive first aperture therein without orbital rotation of one
part about the other. Preferably the rotation allows the
portion 16A and the other portion 16B of the second aperture
to be and to remain mutually parallel since this will faci-
titate insertion of the drop wire 18. The wire holders 36
may have a circular protrusion 39 at their undersides which
allows rotational mounting in a surface of the base.
Such sliding o~ the bases 26 and rotation of the wire
holders 3B will however result in the portions 16A and 16B
becoming laterally separated. Since the amount of variation
in spacing of the binding posts is unlikely to be very
large, tolerance in the fit of the drop wire in the second
aperture may be sufficient to allow insertion of the drop
wire.
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The effect of separtion o~ the bases 3B and rotation oE
the wire holders 37 is shown in figures 11~ and llB.
Figure 12 shows a variation on the design of figures 10
and 11, in which the first and second parts 8A, 8B are sli-
dably rixed to each other, the direction of sliding being
substantially parallel to a substantially straight line
along which lie the portion 16A and other portion 16B of
the second aperture. The pins 38 or other means can be seen
to be set at the desired orientation, generally parallel to
the portions 16A and 16B.
The adapter of figure 13 comprises a first part 8A and a
second part 8B, each of which may be of unitary construction
or made of two or more pieces that are fixed, preferably,
immovably, together.
Each part has a first aperture 10 having an upper part
13 (as drawn) of larger diameter for receipt of a cap, and a
lower part 14 of smaller diameter through which a binding
post protrude. The first and second parts 8A, 8B may be
interconnected by a flexible connector 40. The connector
may comprise a wire, or cord or yarn, or a web of a
material.
Such a connector 40 may be bonded to a surface of the parts
8A, 8B, may be inserted into a slot in the parts or may be
integral with each part. If desired, the connector may be
adjustable in the sense that the separation between the
parts 8A and 8B can be altered and then at least temporarily
fixed at the new value.
The first sur~aces oE the parts 8A, 8B (ie. the under-
sides as drawn) may have a recess preferabLy substantiaLly
concentric with the ~irst apertures, which recess may con-
tain a sealing material such as a gel. Such a sealing
material may provide an environmental seal around binding
posts that enter the first apertures.
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A part (8~ or 8B) of the two part adapter of the gen-
eral type shown in figure 13, but without the web 40 may
be supplied and used alone, ie. without the other of its
pair, or they may be used in pairs but supplied without the
web.
For the avoidance of doubt it is here stated that the
invention provides a terminal block, an adapter and com-
ponents therefor, and methods, for making electrical connec-
tions, particularly in the telecommunications network, and
particularly to multi-core cables. Any of the housing, cap,
binding posts, cutters, sealing means, etc. may be chosen~
