U.S. patent number 3,838,206 [Application Number 05/353,489] was granted by the patent office on 1974-09-24 for wire connector for two electric wires, which may possible be connected to electric detonators.
This patent grant is currently assigned to Nitro Nobel AB. Invention is credited to Kjell Eklund.
United States Patent |
3,838,206 |
Eklund |
September 24, 1974 |
WIRE CONNECTOR FOR TWO ELECTRIC WIRES, WHICH MAY POSSIBLE BE
CONNECTED TO ELECTRIC DETONATORS
Abstract
There is disclosed a connector for conductively connecting the
stripped ends of two insulated conductor wires without requiring
the use of tools or insulation material such as insulation tape.
The connector comprises an outer sleeve into which is fitted a
shorter inner sleeve. The stripped end of one of the conductors is
inserted between the inner sleeve and the outer sleeve and secured
to the inner sleeve. The inner sleeve is secured against axial
displacement within the outer sleeve and rotation relative thereto.
The stripped end of the second conductor is inserted into the inner
sleeve and the stripped ends of both conductors are of a length
such that they protrude from the inner sleeve into the outer
sleeve. These protruding end portions are joined by helically
twisting the wire ends by axially rotating the sleeve assembly
while holding the conductor wires protruding from the outer
sleeve.
Inventors: |
Eklund; Kjell (Orebro,
SW) |
Assignee: |
Nitro Nobel AB (Gyttorp,
SW)
|
Family
ID: |
20268282 |
Appl.
No.: |
05/353,489 |
Filed: |
April 23, 1973 |
Foreign Application Priority Data
|
|
|
|
|
May 12, 1972 [SW] |
|
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6276/72 |
|
Current U.S.
Class: |
174/87;
102/202.5 |
Current CPC
Class: |
H01R
4/22 (20130101) |
Current International
Class: |
H01R
4/00 (20060101); H01R 4/22 (20060101); H01r
007/06 () |
Field of
Search: |
;102/28
;339/213,221,244,276 ;174/87 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pendegrass; Verlin R.
Attorney, Agent or Firm: Hane, Baxley & Spiecens
Claims
I claim:
1. A connector for conductively connecting stripped ends of two
insulation covered conductor wires, said connector comprising: an
outer sleeve and an inner sleeve of shorter length than the outer
sleeve and nested therein in coaxial relationship, said inner
sleeve being retained in the outer sleeve against axial
displacement and rotation relative thereto, the stripped end of one
of the conductors being inserted between the inner wall surface of
the outer sleeve and the outer wall surface of the inner sleeve
secured to the latter, the stripped end of said one conductor being
inserted into the inner sleeve, the stripped ends of both
conductors being of a length such that stripped portions of both
conductors protrude from the inner sleeve and extend into the outer
sleeve, said protruding stripped conductor portions being helically
twisted together, thereby conductively joining the two
conductors.
2. The connector according to claim 1 wherein the outer sleeve is
made of insulation material and the inner sleeve is made of
electrically conductive material.
3. The connector according to claim 2 wherein the outer sleeve is
made of pliable plastics material and the inner sleeve is made of
pliable metal.
4. The connector according to claim 1 wherein said outer sleeve has
in its wall a peripheral outwardly protruding groove and the inner
sleeve has in its wall a peripheral outwardly protruding collar,
said collar being engaged with said groove.
5. The connector according to claim 4 wherein the stripped end of
said one conductor terminates in a bent back portion, said bent
back portion extending into the inner sleeve, thereby securing said
conductor against axial displacement relative to said sleeve.
6. The connector according to claim 5 wherein the stripped end of
said one conductor is clamped between said collar and the groove
defining wall portions of said outer sleeve.
Description
The present invention is related to a wire connector for achieving
electric contact between two electric wires where adjoining
connecting wires each may be connected to an electric detonator.
The function of the wire connector is primarily to connect a
greater number of electric detonators in series. Each electric
detonator has one fuse wire and one wire, which is terminated at a
wire connector. Known wire connectors are usually designed as
cylindrical tubes or sleeves, which are sealed at one end and
preferably made of plastic material. The wire connector sleeve is
internally fitted with a tube of electrically conducting material
such as aluminum and which inner tube more or less lines the
internal surface of the wire connector sleeve. Inserted between the
sleeve and the metal tube is one end of an electric wire, which
preferably is insolated, whereas the length of wire inserted
between the sleeve and the metal tube is stripped. The lower part
of the wire passes the lower edge of the metal tube and is at its
inner end U-bent and inserted back into the tube. The tube with
thus located wire end is then pinched together in such a way that
the inner peripheral surface of the lower end of the tube is
divided into two sections, which are closely facing each other and
squeezing the inserted wire end. The pinched metal tube is now of a
more or less kidney-shaped character. The wire connector with thus
fastended wire is now prepared to receive a second wire end from an
adjoining detonator, which wire end is stripped and inserted into
the tube. In order to achieve electric contact with the tube, the
second inserted wire may be U-bent or provided with a tin plate, so
that contact is obtained with the inner peripheral surface of the
tube. The tin plate may be of rectangular shape and overfolded to
thus fasten the inserted wire to the plate. This procedure of
achieving electric contact has, however, led to contact
unreliability. To avoid this unreliability one has tried to U-bend
the lower part of the connecting sleeve, but in spite of this,
certain contact difficulties have arisen with respect to high or
varying transfer resistances.
The purpose of the present invention is to obtain a wire connector
of above mentioned type, where the resulting electric contact
between the wires is highly effective and where good electric
contact between the connected electric wires is fully ensured.
The new wire connector is in general of the same design as the
above described wire connector and has also an internal metal tube
and an electric wire, which is fastened in the same manner as
mentioned above. The novelty of this invention is that the metal
tube only has a length sufficiently long to lock the one wire end.
The length of the tube may for example be only one-fourth of known
length and need not be of electrically conducting material. Above
the metal tube the fastened wire is stripped for a length of, for
example, approximately 2 cm. In accordance with the invention the
wire end, which is to be connected, is in stripped condition
inserted into the connector sleeve in such a way as to place the
stripped length parallel to the length of stripped and fastened
wire above the metal tube. In this situation the connector sleeve
is turned around its own axis. Thus the inserted and stripped wire
is going to be twisted around the length of the stripped and
fastened wire, whereby satisfactory and reliable electric contact
is established at the same time as material savings are obtained by
the fact that the metal tube only needs such a length as required
to fasten one of the wires.
According to a modification of the present invention the wire end,
which is inserted between the inner peripheral surface of the
connector sleeve and the tube of electrically conducting material,
may instead be inserted into the tube proper and anchored to its
bottom. This means that both wire ends are inserted into the tube
proper.
Characteristic properties of the present invention will also be
evident when reviewing our claims below.
The present invention will more closely be disclosed in connection
with attached drawings, where
FIG. 1 shows the methode of application for wire connectors
according to the present invention, where
FIG. 2 shows a connector sleeve with a fastened wire end, where
FIG. 3 shows a connector sleeve according to FIG. 2, where the
second wire end is being inserted, where
FIG. 4 shows the second wire end fully inserted into the connector
sleeve, where
FIG. 5 shows the connector sleeve during the turning movement
around its longitudinal axis, whereby the two wire ends are twisted
around each other and where
FIG. 6 shows the twisted wire ends.
FIG. 1 shows a section of ground provided with three drillholes 2,
3 and 4. Into each of the drillholes an electric detonator
cartridge 5, 6 and 7 is inserted respectivly. Two electrically
isolated conductors are extending from each electric detonator
cartridge, namely the wires 8 and 9 from the cartridge 5, the wires
11 and 12 from the detonator cartridge 6 and the wires 14 and 15
from the detonator cartridge 7. The wire 9 is at its one end
provided with a wire connector 10, which will be described in more
detail hereinafter. The wire 11 from the electric detonator
cartridge 6 is inserted into said sleeve 10. The wire 12 is thus
also provided with a wire connector 13 of the same type as the wire
connector 10. Into the connector sleeve 13 the other end of the
wire 14 is inserted. By means of the wire connectors any number of
electric detonator cartridges can be interconnected in series. It
should, however, be obvious that the wire connectors not
necessarily have to be wired to electric detonators but may
function as connecting members for various types of circuit
components.
FIG. 2 shows an electric wire connector sleeve 10, which is
identical to the connector sleeve 13. It consists preferably of an
outer cover or sleeve of plastics material but may of course
consist of other materials or combination of materials. At its
bottom the connector sleeve is provided with a tube 16 preferably
of electrically conducting material for example aluminum. The tube
is at its left end expanded into a collar 17, which collar may snap
into an annular groove 10a on the inside of the sleeve 10. The
sleeve is at its left end expanded such that the electric conductor
9 with its stripped end 18 easily may be inserted into the sleeve
in such a way that the wire is located between the outer peripheral
surface of the tube 16 and the inner peripheral surface of the
sleeve or cover. The outermost end of the wire 19 is U-bent and
inserted back into the tube 16 and is in some way or other joined
to the tube for example by welding or by pressing the tube end
together so that the peripheral inner surface of the tube is
transformed into two parts facing each other. The wire end 19 is
now sandwiched and squeezed. The function of the tube is thus to
fasten the wire end 19 and the tube may be made of any material,
which will perform this function. A conceivable material is even
plastics. The wire 18 and the tube 16 are preferably inserted into
the sleeve 10 simultaneously and in the process the wire is kept
fastened to the right end of the tube 16. It should also be obvious
that the sleeve may be made out of a plastic tube, that is the
right bottom part may be omitted. The wire 9 has a stripped length
to the left of the tube 16. The described sleeve 10 with inserted
wire 9 is now ready to receive a second wire 20 with its stripped
wire end 21. FIG. 3 shows the wire 20 being inserted into the wire
connector sleeve 10.
FIG. 4 shows the wire 20 fully introduced, where it is clearly
shown that the stripped sections 18 and 21 of the wires 9 and 20
are approximately of simular lengths. A turning movement to join
the wires is now possible. When the wires are in the position shown
in FIG. 4, the sleeve 10 is turned around its longitudinal axis. On
account of tha fact that the wire 9 is rigidly fastened to the
sleeve 10 a twisting of the wires will occur when turning the
sleeve around its longitudinal axis as is clearly indicated by FIG.
16.
The described invention may be varied within wide limits, whereby
the essential points are, that both of the wires are peeled at the
sections where they are to be joined by twisting and that one of
the wire ends is rigidly connected to the connector sleeve, which
when turned causes the one wire to move around the second wire and
thus to be twisted around and joined to the second wire.
The electrical wire connector may with great advantage be used
pre-connected to one of the wires of an electric detonator whereby
the second wire end before the use of the detonator is inserted
into the connector sleeve and thus protected.
Before wiring the inserted wire end is withdrawn and in its place
is that wire introduced, which is to be twisted onto the wire,
which is fastened to the wire connector.
* * * * *