Improvements in or relating to the 'Insulation of Electrical Conductors.
Year: 1890

page_text: Date of Application, 29th Dec., 1890
Complete Specification Left, 24th Sept., 1891-Accepted, 24th Oct., 1891
PROVISIONAL SPECIFICATION.
Improvements in or relating to the 'Insulation of Electrical
Conductors.
A. communication from JEAN BAPTISTE FERDINAND FRÉDUREAU, of 18, Rue
Lafayette, Paris, in the Republic of France, Mining Engineer.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E., do hereby declare the nature of this invention to be as follows:-
This invention relates to electrical conductors such as wires, cables or tubes
insulated on the outside in bundles and each separately by means of a natural or
artificial silicious substance such as ardoisite schist, silicious sand, asbestos, mica, or
the like either in a pulverized or solid state in the shape of dises spherical caps
or other pieces of any suitable form terminating at either end in a spherical surface,
one of which is convex and the other concave, such pieces being either hollow or
solid and perforated with one or more openings for the passage of the electrical
conductors and in certain cases of natural or forced currents of air.
In all these cases a thorough insulation is obtained far superior to any insulating
devices hitherto used and affording absolute security even should an excessive
rise of temperature take place while at the same time it enables branches to be
readily formed.
Single wires, cables, or tubes contained in a main damp proof conduit are supported
at certain intervals by silicious insulating discs and are insulated from each other by
silicious powder filling up as completely as practicable the conduit. The supporting
discs may be made of one piece or composed of sections.
For taking off branches from the main conductors a sleeve is connected by
damp-proof joints to the adjacent ends of two sections of the conduit the said
sleeve being provided with tubular insulating posts or sleeves through which the
branches are passed.
Instead of the cylindrical form the conduit may assume the shape of a trough
or other similar shapes which will be found preferable in many instances as it allows
of readily laying the successive wires, cables or tubes etc.
Tubular conductors may be arranged concentrically and be insulated both on the
outside and one from the other by means of silicious powder they being retained in
position by means of concentric insulating silicious discs. To allow for the
expansion of the tubes their connection may be made by means of the junction
pieces screwed on to the adjacent ends of two sections of each tube and connected
by flexible arms or conductors. The short tubes or posts for the passage of the
branches may in this case be arranged on the flexible arms or conductors to which
the branch wires are attached.
For insulating a flexible conductor (such as a wire or a cable) it is passed through
a series of spherical caps either solid or hollow composed of a silicious substance
and embedded in each other. By this means thorough insulation is ensured while
the flexibility of the conductors remains undiminished. Where hollow caps or
cups are used the hollow spaces may be filled with a flexible and damp-proof
insulating material such as gutta-percha, tar, or the like.
Instead of caps, pieces of any suitable shape may be employed provided they are
adapted to fulfil the identical purpose and terminating at either end in a spherical
surface one convex and the other concave.
A number of these conductors with spherical joints may be arranged together in
one common conduit.
All solid silicious insulating bodies may be made damp-proof if required by being
steeped in paraffin or like material.

page_text: The apparatus may be so arranged either by perforating the supporting discs or
otherwise as to allow of air circulating within the main conduit which may prove
useful in preventing the prejudicial effects of 'electrical condensation liable to occur
in the solid insulating. bodies; and the insulating powder is then dispensed with; the
discs alone being retained for insulation..
Dated this 29th day of December 1890.
W. P. THOMPSON & BOULT,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to the Insulation of Electrical.
Conductors.
A communication from JEAN BAPTISTE FERDINAND FRÉDUREAU, of 18, Rue
Lafayette, Paris, in the Republic of France, Mining Engineer.
I, ALFRED JULIUS BOULT of 323 High Holborn' in the County of Middlesex,
M.I.M.E., 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:-
:
This invention relates. to electrical conductors such as wires, cables or 'tubes
insulated on the outside; collectively and each separately by means of an artificial
silicious substance called "ardoisite" either in a pulverized or solid state in the
shape of discs, spherical caps or other pieces of suitable form terminating at eithèr
end in a spherical surface, one of which is convex and the other concave, such
pieces being either hollow or solid and perforated with one or more openings for
the passage of the electrical conductors and in certain cases of 'natural or forced
currents of air.
In all these cases a thorough insulation is obtained far superior to any insulating
devices hitherto used and affording absolute security even should an excessive
rise of temperature take place while at the same time it enables branches to be
readily formed.
In the accompanying drawings several forms of the arrangement 'embodying this
invention are shown.
Figs. 1 and 2 illustrate the insulation of single wires, cables or tubes contained
in a main damp-proof conduit A supported at certain intervals by insulating discs
made of ardoisiter being at the same time insulated from each other by
powder of ardoisite filling up as completely as practicable the conduit A.
supporting discs may be made of one piece as in Fig. 2 or composed of
sections as in Fig. 3.
The
Figs 4 and 5 show the manner in which branches are formed. A sleeve M con-
necting by damp-proof joints two sections of the conduit is provided with tubular
insulating posts or sleeves B through which the branches O are passed:
Instead of the cylindrical-form the conduit may assume the shape of a trough
(Figs. 6 and 7) which will be found preferable in many instances as it allows of
readily laying the successive wires, cables or tubes etc.
Figs. 8 and 9 illustrate a method of arranging tubular conductors D concentrically:
and insulating them both on the outside and one from the other: by means of
ardoisite powder E, they being retained in position: by means of concentric
insulating discs of ardoisite G. To allow for the expansion of the tubes,
their connection may be made by means of the junction pieces P (Fig: 9) screwed
on to both the adjacent ends of two sections of each tube and connected by flexible
arms or conductors F: The short tubes or posts for the passage of the branches
may in this case also be arranged on the flexible arms or conductors F to which the
branch wires are attached..
Figs. 12, 13, 14 and 15 show a flexible conductor-H (such as a wire for a cable)

page_text: passed through a series of spherical caps I either solid as in Figure 12 or hollow
as in Fig. 13 composed of ardoisite and embedded in each other. By this means
thorough insulation is ensured, while the flexibility of the conductors remains
undiminished. Where hollow caps or cups I are used (Fig. 13) the hollow spaces
may be filled with a flexible and damp-proof insulating material such as gutta-
percha, tar or the like.
Instead of caps, pieces of any suitable shape may be employed provided they
are adapted to fulfil the same purpose and terminating at either end in a
spherical surface, one convex and the other concave. Figs. 18, 19, 20 and 21
exemplify this.
A number of these conductors with spherical joints may be arranged together
in one common conduit as illustrated by Figs. 16 and 17.
These solid insulating bodies of ardoisite may be made damp-proof, if required,
by being steeped in a bath of paraffin, resin or like material. It only remains to
state in conclusion that the arrangement shown in Figs. 10 11 16 and 17 allows a
system of air circulation being established within the main conduit which may
prove useful in preventing the prejudicial effects of electrical condensation liable
to occur in the solid insulating bodies. In Fig. 10 the supporting discs are
shown provided with openings a a a... for the passage of air. In Figs. 16
and 17 the insulating pieces themselves are so shaped as to allow of the free
passage of air.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is :-
1. The manufacture and use of electrical conductors such as wires, cables or
tubes insulated on the outside collectively and each separately by means of an
artificial silicious substance called "ardoisite," either pulverized or in a solid state
in the form of discs, spherical caps, or other pieces of any suitable form terminating
at either end in a spherical surface one of which is convex and the other concave
such pieces being either hollow or solid and perforated with one or more openings
for the passage of the electrical conductors and in certain cases of natural or
forced currents of air substantially as described.
2. The employment of an artificial silicious substance called ardoisite in the
form of powder or solid for the purpose of insulating electrical conductors.
Dated this 24th day of September 1891.
W. P. THOMPSON & BOULT,
Agents for the Applicant.