FIELD OF THE INVENTION
[0001] The present invention relates to an electrical connector particularly but not exclusively
for use in the telecommunications industry.
BACKGROUND ART
[0002] Where it is required to distribute telephone lines from the local telephone exchange
cable, be it aerial or underground, separate distribution points are established appropriately
located either at the top of telephone poles or on the walls of the building requiring
the telephone service.
[0003] These distribution points consist of block terminals containing telephone wire connectors,
which from time to time have to be removed for the purposes of testing or rearrangement.
[0004] Up to relatively recent times these connectors have been of the screw connection
type, but it is becoming more common these days to employ the use of insulation displacement
connectors which do not require the wire insulation to be stripped to effect the connection
thus producing a saving in time and cost.
[0005] However the majority of insulation displacement connectors presently on the market
are not re-usable and are limited in the size and type of wire with which they can
deal.
SUMMARY OF THE INVENTION
[0006] It is accordingly an object of the invention to provide an insulation displacement
electrical connector which is free of the disadvantages of the prior art in particular
is re-usable and capable of deployment over a wide range of wire sizes and types.
[0007] According to the invention there is provided an electrical connector comprising
a connector body, means on the connector body defining a slit for severing insulation
on a wire pair to be connected passed through the slit, and shorting the pair therein,
and a slidable member on said body actuable to move a said wire pair through and away
from said slit.
[0008] The above device solves the problem of re-usability because the slidable member,
in the form of a plunger guided for reciprocable movement in the connector body, is
actuable by finger pressure to withdraw the wire pair from the slit thereby to release
the wires for testing purposes in contrast to known insulation displacement connectors
where this is not possible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Other features and advantages of the invention will become apparent from the following
description of a preferred embodiment of the invention taken with reference to the
accompanying drawings wherein:
Figure 1 is a top view of a re-usable connector according to an embodiment of the
invention;
Figure 2 is a side view along the arrow P of Figure 1;
Figure 3 is a side view along the arrow R of Figure 2;
Figure 4 is a top view of the wire insulation-severing and electrical pick-up mechanism
of the connector of Figure 1;
Figure 5 is a view looking along the arrow T of Figure 4;
Figure 6 shows representative side and end views of the actuating plunger of the connector
of Figure 1;
Figure 7 is a view of an alternative embodiment of the main connector part of the
re-usable connector depicted in four stages of construction for illustrative purposes
only; and
Figure 8 (a) and 8 (b) show a side view and end view respectively of the main connector
part formed from the four stage process depicted in Figure 7, Figure 8 (b) being a
view along the arrow A in Figure 8 (a).
BEST MODES OF CARRYING OUT THE INVENTION
[0010] The insulation displacement re-usable connector shown in the drawings comprises a
connector block 1 of square cross section, made of an insulating material, and formed
of two identical separable block half-sections 2 and 3.
[0011] An axial passageway 4 of circular cross section extends through the block 1, intercepting
axially aligned transverse entrant passageways 5 and 6 leading to the passageway 4.
[0012] The transverse passageways 5 and 6 are of circular and square cross section respectively,
lying in the plane of separation of the block half-sections 2 and 3.
[0013] The entrant passageways 5 and 6 are formed from cooperating opposing grooves 7 and
8 provided in the mating surfaces 9 of the block half-sections 2 and 3.
[0014] The block half-sections 2 and 3 are held together by means of four screws 10 and
associated nuts 11, although other connection means are possible, for example by the
provision of cooperating formations on the mating faces which would avoid the need
to employ screws and nuts.
[0015] A cylindrical brass collar 12 is located in snug-fit relationship, in the axial passageway
4.
[0016] The collar 12 is split at 13. A pair of identical semi-circular plates 14 are brazed
or welded between the opposing edges E defining the split 13 of the collar 12, to
form a pair of longitudinal slits S between opposing edges of the plates 14, both
slits S extending midway between the edges E and having axes which are at 90° to the
axis of the collar 12. The entrance to the slits S within the collar 12 are widened
out at Sʹ as shown.
[0017] The plates 14 project from the peripheral surface of the collar 12, to engage the
entrant passageway 5 as seen in Figures 1 and 2.
[0018] An aperture 15, see Figure 4, is formed in the peripheral surface of the collar 12,
the axis of the aperture 15 lying on that of the entrant passageway 6, and thus on
the axis defined by the plates 14.
[0019] A plunger 16 is positioned for slidable movement in the entrant passageways 5 and
6 of the connector block 1.
[0020] The plunger 16 has two plunger halves, 17 and 18, one half 17 of which is of circular
cross section and which engages in the collar 14 to protrude from the entrant aperture
5, the other half 18 being of square cross section to engage the aperture 15 and protrude
from the entrant aperture 6.
[0021] The cylindrical half 17 of the plunger 16 has a pair of circular bores 19, positioned
such that, with the square-sectional plunger half 18 positioned in the square sectioned
entrant aperture 6, and unable to rotate thereby, the openings to the bores 19 are
moveable in line with the slits S between the plates 14, as the plunger 16 is moved
in the direction of the arrow A in Figure 1.
[0022] To connect a pair of wires of predetermined wire size, each wire of the pair are
inserted in the bores 19. The plunger 16 is then depressed in the direction of arrow
A to cause the wires to enter both upper and lower slits S between the plates 14.
This acts to sever the insulation in the wires to effect a closed circuit in the pair
through the plates 14.
[0023] Depression of the plunger 16 in the opposite direction, releases the wires from the
slits S for testing purposes. The connector is then re-usable.
[0024] The material of the plates 14 is such that the slits S as by yielding elastically,
are able to accommodate various wire sizes in the range 0.5mm to 1.1mm in diameter,
without varying the dimension of the slit itself.
[0025] A variant of the invention is shown in Figures 7 and 8. This was developed to avoid
the two part manufacture of the main connector part of the device comprising the brass
collar 12 and plates 14 of the Figure 1 through 5 embodiment, and lends itself more
readily to mass production using rapid stamping and forming techniques.
[0026] In this alternative embodiment the main connector part of the device, as shown in
Figure 7, stage 1, is made from an integral piece of flat spring copper strip 20,
having a rectangular cut-out 21, in each end of the strip 21 and on its longitudinal
axis.
[0027] An oval hole 22 is provided centrally of the strip 21.
[0028] Each limb 23 formed by the cut-outs 21 is turned over at its end to form a spaded
end portion 24 the plane of which lies at right angles to the plane of its associated
side piece 22, as shown in Figure 7, stage 2.
[0029] The strip 20 is then folded, as shown in Figure 7, stage 3, into a U-shape 25.
[0030] End sections 26 of the limbs 23 are then turned over, as shown in Figure 7, stage
4, such that the edges 27 of those spaded end portions 24 at either end of the strip
21 and lying on the same side of the longitudinal axis of the strip 20, face one another,
and under the spring tension of the strip 21, to form a pair of narrow slits 28. An
oval passageway 29 on the same axis as the oval hole 22, see Figure 8, is thus formed
between one respective pair of spaded end portions forming one of the slits 28 and
the other respective pair forming the other of the slits 28, with the plane of the
slits 28 passing through the axis of the oval passageway 29 and the oral hole 22 in
the body of the strip 20.
[0031] The main connector part thus formed from the strip 20 is positioned in the axial
passageway of a connector block (not shown) of the type 1 discussed with reference
to Figures 1 to 6, the axial passage being designed to accept the folded strip in
tight fit secure relationship.
[0032] In this embodiment however, the device is operable by means of a plunger 30, see
Figure 8, of oval cross-section corresponding to the oval holes 22 and 29 in the main
connector part formed from the strip 20. Hence the corresponding axially aligned passageways
in the connector block of this alternative embodiment in which the plunger 30 is slidably
mounted, namely those corresponding to entrant passageways 5 and 6 in the Figure 1
to 5 embodiment, are of oval crosssection as will be appreciated. The plunger 30 is
thus unable to rotate but is free for axial slidable movement in a coaxial passageway
extending through the connection block provided by the oval holes 22 and 29, and the
oval passageways in the body of the connector block.
[0033] The plunger 30 is provided with holes 31 for receiving the wire to be connected lying
in alignment with the slits 28. The plunger 30 may thus be actuated by manual operation
to force the wires to be connected through the slits 28, thereby to pierce the wire
insulation in the slits 28, and make the electrical connection of the two wires as
required through the copper strip 20 of the main connector part.
[0034] Since the copper strip is spring tensioned, the slits 28 will accommodate electrical
wire of varied dimensions, due to their yieldability as with the slits S of the Figure
1 to 5 embodiment.
[0035] Although the invention has particular applicability to telephone wire connectors,
it is not limited thereto, one of its alternative uses for example, is as a replacement
for a screw terminal in electrical plugs and sockets.
1. An electrical connector comprising a connector body, means on the connector body
defining a slit for severing insulation on a wire pair to be connected passed through
the slit, and shorting the pair therein, and a slidable member on said body actuable
to move a said wire pair through and away from said slit.
2. A connector as claimed in claim 1 wherein said slit defining means comprises a
pair of electrically conducting semi-cylindrical plates spaced one from the other
to form a said longitudinal slit between each opposed longitudinal edge of said spaced
plate members.
3. A connector as claimed in claim 2 wherein said spaced semi-cylindrical plates form
a circular passageway in said connector body for receiving said slidable member.
4. A connector as claimed in claim 3 wherein said slidable member is formed of two
halves, one half being of circular cross-section and slidably engaging said circular
passageway, the other half being of square cross-section engaging a further passageway
in said body of complementary cross-section thereto, said circular and square passageways
being co-axial.
5. A connector as claimed in claim 4 wherein said slidable member has a pair of spaced
axially aligned holes in its circular half, said holes being in alignment with said
opposed slits.
6. A connector as claimed in claim 5 wherein said body has a central passageway the
axis of which is perpendicular to the axis of said circular and square passageways,
a cylindrical metallic collar positioned in said central passageway and provided with
openings for access to said square and circular passageways for said slidable member,
said collar having an axially directed split lying in the path of said longitudinally
opposed slits in said plates.
7. A connector as claimed in claim 6 wherein said semi-circular plates are held in
said body by being attached to said collar in cut-outs along the opposed edges of
said split, said cut-outs being complementary to said semi-circular plates.
8. A connector as claimed in claim 1 wherein said slit defining means is formed from
a spring strip of electrically connecting material, each end of the strip having
a flat end section turned-out of the plane of the strip, the strip being folded such
that an edge of said flat section faces the edge of the other flat section across
said slit.
9. A connector as claimed in claim 8 wherein two flat end sections are turned out
of the plane of the strip at each end thereof to form two slits for severing wire
insulation and lying in a plane containing the axis of the folded strip.
10. A connector as claimed in claim 9 wherein an oval passageway is formed between
each respective pair of flat end sections defining a said slit, the axis of said passageway
being coaxial with an oval hole formed centrally of the folded strip, said oval passageway
and said oval hole receiving said slidable member of corresponding cross section.
11. A connector as claimed in any preceding claim wherein side slidable member projects
from said body at either end thereof providing for thumb and finger actuation as between
said body and one end of said slidable member respectively.