Improvements in the Manufacture of Electric Cables.
Year: 1890

page_text: Date of Application, 18th Feb., 1890
Complete Specification Left, 13th Nov., 1890-Accepted, 17th Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Electric Cables.
I, JOHN EDWARD KINGSBURY of 79 Coleman Street in the City and. County of
London Manager (a communication to me from abroad by The Western Electric
Company of Chicago, Illinois, United States of America) do hereby declare the
nature of this invention to be as follows:-
This invention relates to the manufacture of electric cables and its object is to
reduce the static capacity of such cables and at the same time provide for readily
removing the core or the greater portion thereof whenever such removal from the
enclosing pipe may be desired.
Heretofore cables having the core of insulated conductors protected by a pipe or
sheathing of lead have been filled, that is to say, the space or interstices between the
pipe and the core, have been filled in various ways with various substances and by
various processes.
The invention herein consists in placing the core of insulated conductors deprived
of moisture within the pipe and then forcing insulating filling such for example as
melted paraffin into both ends of the pipe thereby compressing the gas and air
between the said fillings-gas under pressure is first forced into the pipe and then
insulating filling material under a greater pressure is forced into the ends of the pipe.
I use preferably a generator of carbonic-dioxide and a charging chamber containing
in its lower part the insulating filling and in its upper part filled with gas under
pressure from the generator the gas also as it enters the chamber may be caused to
rise up through the insulating material so as to more or less aerate it as described in
the Specification of the Patent No. 442081.
The pressure of gas is produced in the usual way by allowing sulphuric acid to flow
into the chamber containing marble dust or bi-carbonate of soda.
The ends of the cable are preferably connected to a pipe leading to the charging
chamber and there branching, each branch containing a cock or valve and one branch
extending down into the insulating filling and the other branch extending only into
the upper portion of the chamber containing the gas-a cock is also provided upon
each end of the section of cable which is to be protected.
is
When the pressure reaches any desired limit as shown by a gauge the gaz
allowed to pass into the cable pipe. The connection between the gas reservoir and
the cable pipe is then closed and the other connection between the melted insulated
material and the cable pipe is opened. More gas is then produced in the generator
as before and the pressure allowed to rise high enough to force the melted insulated
material into the ends of the pipe and thereby still further to compress the gas which
had previously been admitted.
Thus by manipulating the valves and observing a guage the flow of gas and its
pressure and the flow of the melted paraffine or other insulating substance may be
regulated and controlled.
In practice the ends are filled to a distance of about twenty five feet each
regardless of the length of the cable, whether it is two hundred feet long or a
thousand.
In order that the static capacity of the cable may be as low as possible I avoid the
use of a liquid or plastic insulating substance in and about the core as far as possible.
A filling of some kind to act as a dam to prevent water from running longitudinally
in the pipe is found necessary at the manholes where cables are laid under ground,
ince the pipe is so liable to mechanical injury at the manholes. A short section of
illing at the manholes is however sufficient, especially where the core is protected by

page_text: by a lead pipe which has been tested by pneumatic or hydraulic pressure from
within.
The cable, that is to say, each section of the cable is therefore filled at each end a
short distance with insulating substance, the gas or air or combination of gases in the
pipe being compressed between the insulating fillings at the two ends.
The paraffine or other insulating filling is forced in hot, after which it is allowed
to cool before the pressure is removed so as to hold the gas or air under pressure.
Dated this 18th day of February 1890.
J. E. KINGSBURY
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Electric Cables.
I, JOHN EDWARD KINGSBURY of 79 Coleman Street, in the City and County of
London, Manager, (a communication to me from abroad by The Western Electric
Company, of Chicago, Illinois, United States of America) do hereby declare
the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:
This invention relates to the manufacture of electric cables and its object is to
reduce the static capacity of such cables and at the same time provide for readily
removing the core or the greator portion theroof whenever such removal from the
enclosing pipe may be desired.
Heretoforo cables having the core of insulated conductors protected by a, pipe or
sheathing of lead have been filled, that is to say, the space or interstices between the
pipe and the core, have been filled in various ways with various substances and by
various processes.
The invention herein consists in placing the core of insulated conductors deprived
of moisture within the pipo and then forcing insulating filling such for example as
melted paraffin into both ends of the pipe thereby compressing the gas and air
between the said fillings-gas under pressure is first forced into the pipe and then
insulating filling material under a greater pressure is forced into the ends of the pipe.
I use preferably a generator of carbonic-dioxide and a charging chamber containing
in its lower part the insulating filling and in its upper part filled with gas under
pressure from the generator the gas also as it enters the chamber may be caused to
rise up through the insulating material so as to more or less nerate it as described in
the Specification of the Patent No. 442081.
The pressure of gas is produced in the usual way by allowing sulphuric acid to flow
into the chamber containing marble dust or bi-carbonate of soda.
The ends of the cable are preferably connected to a pipe leading to the charging
chamber and there branching, each branch containing a cock or valve and one branch
extending down into the insulating filling and the other branch extending only into
the upper portion of the chamber containing the gas-a cock is also provided upon
each end of the section of cable which is to be protected.
When the pressure reaches any desired limit as shown by a gauge the gas is
allowed to pass into the cable pipe. The connection between the gas reservoir and
the cable pipe is then closed and the other connection between the melted insulated
material and the cable pipe is opened. More gas is then produced in the generator
as before and the pressure allowed to rise high enough to force the melted insulated
material into the ends of the pipe and thereby still further to compress the gas which
had previously been admitted.
Thus by manipulating the valves and observing a gauge, the flow of gas and its
pressure and the flow of the melted paraffin or other insulating substance may be
regulated and controlled.
In the accompanying drawing I have illustrated suitable apparatus for carrying
out this method or process, it being understood that I do not limit myself to any
particular apparatus or combination of devices for doing the work.

page_text: The coil of pipe a may be of any desired length. It is connected at its different
ends with the reservoir 6 containing the melted paraffin and gas under pressure.
The cocks c d are both opened when the coil is being tilled; first, the gas cock e will
be opened and the paraffin cock closed. The gas is then generated in the
generator gat such pressure as is required. A pressure from seventy to eighty
pounds to the square inch is found sufficient. The gas cock e remaining open the
coil of pipe a will be filled with the gas and the air contained therein will be placed
under the desired amount of compression. The gas cock e is now shut and the
paraffin cock fopened and the pressure still further increased say up to ninety or
one hundred pounds per square inch. The necessary increase of pressure will vary in
each individual case according to the length of the cable which is being filled. The
additional pressure necessary to force the paraffin the requisite distance into the ends
of the cable which is being filled depends upon the length of said cable and is
therefore necessarily determined independently in each case.
In practice the ends are filled to a distance of about twenty-five feet each
regardless of the length of the cable, whether it is two hundred feet long or a
thousand. After sufficient paraffin has been forced into the pipe the cocks c d are
closed and the paraffin allowed to cool. The reservoir is designed for supplying
the tank with paraffin. I have shown the core at i bared, the lead pipe being cut away
for a short distance.
The gas as is well understood is generated in the generator 9 and is conducted
therefrom into the reservoir b containing the melted paraffin. This tank is not
completely filled with paraffin and hence the gas will rise to the top of the tank and
thus when the paraffin cock fis closed and the gas cock e opened the gas will be
forced from the reservoir 6 through the open cock e into the pipe a as before
described.
The pipe or cable a we will say is a coil four hundred feet long. The core of
insulated wires having been drawn into the pipe it is desired to fill the space about
the core for say twenty-five feet at each end of the section. The pipe being of lead
is of sufficient strength to stand considerable pressure from within.
In order that the static capacity of the cable may be as low as possible I avoid the
use of a liquid or plastic insulating substance in and about the core as far as possible.
A filling of some kind to act as a dam to prevent water from running longitudinally
in the pipe is found necessary at the manholes where cables are laid under ground,
since the pipe is so liable to mechanical injury at the manholes. A short section of
tilling at the manholes is however sufficient, especially where the core is protected by
a lead pipe which has been tested by pneumatic or hydraulic pressure from within.
The cable, that is to say, each section a of the cable is therefore filled at each end a
short distance with insulating substance, the gas or air or combination of gases in the
pipe being compressed between the insulating fillings at the two ends.
The paraffin or other insulating filling is forced in hot, after which it is allowed to
cool before the pressure is removed so as to hold the gas or air under pressure.
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
1. The method of manufacturing electric cables which consists in forcing
insulating filling into both ends of a section thereof and thereby compressing the
gas or air between said fillings, substantially as described.
2. The method of manufacturing telegraph cables which consists in drying the
core of insulated conductors drawing the same unsaturated into the pipe, forcing an
insulating filling into the two ends of the pipe and thereby compressing the gas or
air between said fillings, substantially as and for the purpose specified.
3. The method which consists in first drawing the dry unsaturated core into the
cable and then forcing an insulating filling while melted into the ends of the pipe
and allowing the insulating filling thus forced into the ends of the pipe to solidify,

page_text: thereby holding the atmosphere between the fillings compressed, substantially as
described.
4. The method of manufacturing telegraph cables which consists in drying the
core of insulated conductors drawing the same unsaturated into the pipe, forcing gas
or air into the pipe and then forcing melted insulating filling into the two ends of
the pipe allowing the insulating filling to solidify before the pressure is removed
whereby the gas or air is held under pressure, the core being left dry and unsaturated
between the fillings, substantially as described.
Dated this 6th day of November 1890.
J. E. KINGSBURY.