An Improved System of Running and Insulating Concentric Electrical Conductors, and Appliances in connection therewith.
Year: 1896

page_text: Date of Application, 20th Apr., 1896
Complete Specification Left, 20th Nov., 1896-Accepted, 13th Feb., 1897
An Improved System of Running and Insulating Concentric Electrical
Conductors, and Appliances in connection therewith.
I, GEORGE WILKINSON of 1^ Bishops' Terrace, Fulham Palace Road, in the
County of Middlesex Electrical Engineer do hereby declare the nature of this
invention to be as follows:-
My said invention consists in utilising concentrio electrical conductors, and has
for its objects a method of and means for jointing, and attaching switches, lamp
brackets, fuses, ceiling roses, and all other accessories without requiring these to
be of especial construction as heretofore; and also preserving a high degree of
insulation throughout the system dispensing with casing or armouring except under
certain conditions.
In carrying my invention into effect, I use a cable or wire lead which consists of
a core of twisted wires, covered with a certain thickness of insulating material or
substance and again surrounded by a series of conductors arranged concentrically,
and separated from the ceutral core by the intervening insulation. In connecting
any switch, fuse, or the like, I prefer to separate tho outer wires of the concentric
leads, leaving the central wires intact, and interposing said switch or the like
between said outer wires, re-insulating them according to the potential imposed
upon the system. A certain amount of slack lead is thus preacuted by the
unbroken central cable, and I dispose of this by coiling or twisting it into a recess
formed in the back of the base or sediment of the fitting. The procedure consists
in stripping the outer insulation, uncovering a suitable length of the outer conductor,
which is bound round close to the severed insulation, cut and bent to suit the
proposed attachment, and then either taped or covered by tubes of insulating
material.
In making T joints the insulation is stripped to the outer conducting wires,
which are cut, cleaned, and turned back on each side of the stripping. The
inner conductor is then bared, and a connection made and insulated in the
usual way. A hollow T shell, preferably made in halves, aud tinned to receive
solder, is pressed upon the joint enclosing the central insulated branch. The two
ends of the outer conductor are then twisted around the split T coupling and
soldered, or a binding or bindings may be made with suitable binding wiro, and the
whole sweated together in the process of soldering. Said joiut may then be taped
or otherwise insulated. The pressed or stamped pieces forming the connection
may be made of thin sheet copper or any other suitable metal. A plain or X joint
may be similarly made by a suitable metal connector as above referred to, and the
insulation thereof carried out in the same manner.
In running the wires I prefer to lay the plaster bare to the brickwork of the
building, cutting grooves therein, and laying the concentric conductors therein and
covering them by a semi-tube or like casing, filling in with plaster or the like.
The essential features of my said invention are in the fact that I can utilise any
form of switch, fuse or other fitting, and preserve a perfect insulation, and that
I may dispense with ordinary casing or armouring, and make any form of joint
that may be required without additional labour, or extra risk resulting from
defective insulation. Furthermore, since I break the continuity of the outer

page_text: conductor only; in interposing switches or the like, the degree of high insulation
is at its maximum in installations of concentric wiring according to my said
invention.
1000
FREDK.
WALKER,
73 St. Stephen's Road, Upton Park, E.,
Agent for the Applicant.
An Improved System of Running and Insulating Concentric Electrical
Conductors, and Appliances in connection therewith.
GEORGE WILKINSON of No. 12 Dragon View, Harrogate, in the County of
York formerly of No. 1^ Bishops' Terrace, Fulham Palace Road, in the County of
Middlesex, Electrical Engineer do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My invention relates to an improved system of running and insulating and
generally utilizing concentric electrical conductors and has for its objects, a method
of, and means for jointing and attaching switches, lamps, brackets, fuses, ceiling
roses and all other accessories without requiring these to be of especial construction
as heretofore, also preserving a high degree of insulation throughout the system
dispensing with casing or armouring except under certain conditions.
In order that my invention may be the better understood, I have appeaded the
accompanying sheets of drawings, in which
Figure 1, Sheet 1 is a cross section of the concentric conductor, and Figure 2 an
clevation thereof, showing the several parts separated.
Figure 3 is one half of a plain jointing socket.
Figure 4 is one half of a T joint socket, and
Figure 5 is one half of a four way socket.
Figure 6 is a plan, and Figure 7 a sectional elevation of an insulating box or
cover which is also a base for attachment in some cases; and forins the exterior
of joints according to my said invention.
Figure 8, Sheet 2 is a plan view of a stripping knife for preparing the conductors
ready for jointing or connecting. Figure 9 is an elevation and Figuro 10 is an ond
elevation of the same.
Figure 11 is a plan view of a jointing vice, aud Figure 12 is an elevation of the
saine.
For facility of referance, similar letters indicate corresponding parts throughout
the several views where such indication is admissible.
In carrying my invention into effect, I use a cable Figures 1 and 2, which
consists of a core a of a single conductor or of twisted or parallel wires surrounded
by a covering of suitable insulating material of proper thickness according to
the degree of insulation required. Around this is laid a series of wires c arranged
concentrically, and separated from said central core a by the insulation b. This is
again covered by an insulating substanco or material d of a certain thickness,
which may, if necessary be protected by a thin metallic sheathing or armouring e.
In jointing this cable, the procedure consists in stripping the insulation, and
thus laying bare the concentric conductors a and c. In order to accomplish this,
I use a stripping knife, shown by Figures 8, 9, and 10, Sheet 2. A series of
cutters are fixed by set screws within the heads A A' of the knife, which aro
hinged at II as shown, so that they may be opposite to each other, and sevorally

page_text: adjusted to the requisite length for cutting and stripping the conductor in the
manner shown by Figure 2 Sheet 1. The cutting edges of the cutters i in A' are
opposed to those fixed in the opposite head A, so that, when placed over the
conductor to be stripped, a semi revolution completes the operation, and enables
the stripping knife to be used clear of the triple vice hereinafter to be described,
or any other holding or gripping device of the same kind. Lever handles L Li
enable the stripping kuife to be placed over the cable or conductor to be stripped
and sufficient forco applied to keep the cutting tools i at the required depth whilst
partially rotating the knife as aforesaid. In conjunction with said kuife, I prefer
to employ a triple vice, as shown by the plan view, Figure 11, and elevation
Figure 12, in which three vises E, F, G are fixed upon a table or platform K,.
which is mounted upon a tubular or other pillar M working telescopically within
a socket N attached to a stand O so that the table or platform K
inay be adjusted:
to any required height. For instance, if a T joint is desired to be made, the
continuous cable is gripped by the vises F and G, and the cross cable by the
vice E. The cutting or stripping knife bereinbefore described, is now brought into
operation, and the centre of the continuous cuble, and the end of the cross cable
bared. The central stranded core a Figures 1 and 2, is now connected by splicing
and soldering in the usual manner, and the insulation b made up to the requisite
thickness by wrapping a prepared tape or other insulating material round it.
A pair of T sockets shaped as the single one shown by Figure 4 Sheet 1, are
placed over the insulating layer b. These T sockets, and the other sockets of
different shape, Figures 3 and 5 are preferably stamped or pressed out of thin
sheet metal, which is covered by a coating of tin to facilitate the adherence of
solder, said sockets being placed upon and around the replaced insulation b, the
separate series of wires o of the three cables held by the vises E, F, G, are folded
over said sockets, bound in position by light biuding wire, and the whole soldered.
or sweated together, and then the insulation d is made up by wrappings of insulated
tape or the like. Whilst the three members of the T joint are still held in position
by the vises E. F. G, a recessed cover Figures 6 and 7, preferably of wood, or any
suitable insulating material, is placed over said joint, the members of which pass
through the slotted orifices ff. A disc of paper or other material p is then
pressed upon the open base, and a block of wood or the like pushed in upon the
vice platform K to hold the cover and dise in place, the finished joint being
enclosed. The recess is then filled with bitumeu, or any other insulating material
in a liquid state through a hole g in the front of the cover or elsewhere. The
joint now being released from the vises is ready for replacing in position.
In ordinary installations with the conductors, joints and connections made as.
herein described, I may run the whole of the wiring exteriorly relatively to the
walls of the building carrying the lends ou metal saddles attached to the walls, or
I may run the leads and branches in grooves within and below the surface of the
plaster afterwards filling in said grooves.
lu making a conductor as shown by Figures 1 and 2 I make the outer strands o
of greater sectional area than is usual in ordinary practice in the case of stranded
concentric conductors, in order to obtain greater stability in jointing, and generally
throughout the installation, thus obviating the disadvantage appertaining to
ordinary concentric conductors in which, to secure the same ratio of conductivity
between the strands c and the core a, the former were of too small in soctional area
to afford a reliable jointing, or to withstand the ordinary strains of coiling and
running.
An essential feature of my invention is in the coupling of small switches and
fuses within the interrupted outer strands c of the conductor the central core a
being intact right to the lamp fitting. That is to say a connection made at any T
or other joint would have the terminal ends of one of the outer conductors c
carried through the bux, Figures 6 and 7, Sheet 1, and a short piece of conductor
soldered to the shell, Figures 3, 4 or 5 as the case may be, and also brought
together through the box, both being properly insulated by taping or the like..

page_text: The switch or fuse being attached to the front of the box and coupled to the two
terminal conductor ends thus presenteil, after the recessed portion is filled in with
melted insulating material.
The essential features of my said invention are in, that I can utilize any form of
switch, fuse, or other fitting, and preserve a perfect insulation, and that I may
dispense with ordinary casing, and inake auy form of joint that may be required
without additional labour, or extra risk resulting from defoctivo insulation.
Furthermore, since I break the continuity of the outer conductor only in
interposing switches or the like the degree of high insulation is at its maximum in
installations of concentric conductors according to my invention.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is :-
First. In a system of installing, jointing and insulating concentric electrical
conductors, the construction and employment of a core of a single, or of stranded
or twisted wires a Figures 1 and 2 Sheet 1 of the drawings surrounded by an
insulating sheath b which is again surrounded by a stranded conductor c the
sectional area of which is for the purposes of firm jointing greater in the aggregato
relatively to that of the core, said stranded conductor e being covered by an
insulating sheathing d and in some cases a sheathing or armouring e substantially
as herein described and showu by the appended drawings.
Second. In a system of jointing and insulating concentric electrical conductors
the construction and employment of thin metal sockets, in halves, suitably shaped
az shown by Figures 3, 4 and 5 Sheet 1, and manipulated and insulated in jointing
and enclosed within a joint box, substantially as herein described.
Third. In a system of jointing and insulating concentric electrical conductors
the construction and employmont of a stripping knife for the purposes of jointing
the conductors as herein described only as shown by Figures 8, 9, and 10, Sheet 2
with two heads A A¹ hinged at II carrying graded cuttersi with grip handles L L'
substantially as and for the purposes berein described, with reference to the
accompanying drawings.
Fourth. In a system of jointing and insulating concentric electrical conductors,
the construction and employment of triple vises for the purposes of jointing the
conductors as hurein described ouly E, F, G, as shown by Figures 11 and 12
Sheet 2, fixed upon a telescopic adjustable stand or pedestal M. N. O, substantially
as and for the purposes herein set forth with reference to the accompanying sheets
of drawings.
Fifth. In a system of jointing and insulating concentric electrical conductors
the method of and meaus for, maintaining the inner stranded core a (Figures I
and 2 Sheet 1) intact and inserting switches, fuses or other electrical fittings
within and between the interrupted outer stranded conductor c, attaching said
switches or the like to the joint box (Figures 6 and 7 Sheet 1) substantially as
herein described.
FREDK. WALKER,
73 St. Stephen's Road, Upton Park, London, E.,
Agent for the Applicant.