IMPROVEMENTS IN IN- SULATING TELEGRAPHIC WIRES OR CONDUCTORS, AND IN APPARATUS EMPLOYED . THEREIN, PART OF WHICH APPARATUS IS APPLICABLE TO THE MANUFACTURE OF TUBES FROM INDIA-RUBBER
Year: 1858

page_text: LETTERS PATENT to John Macintosh, of North Bank, Regent's Park, in
the County of Middlesex, for the Invention of "IMPROVEMENTS IN IN-
SULATING TELEGRAPHIC WIRES OR CONDUCTORS, AND IN APPARATUS EMPLOYED
. THEREIN, PART OF WHICH APPARATUS IS APPLICABLE TO THE MANUFACTURE OF
TUBES FROM INDIA-RUBBER."
Sealed the 1st February 1859, and dated the 24th August 1858:
PROVISIONAL SPECIFICATION left by the said John Macintosh at.
the Office of the Commissioners of Patents, with his Petition, on the
24th August 1858.
I, JOHN MACINTOSH, of North Bank, Regent's Park, in the County of
Middlesex, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN INSULATING TELEGRAPHIC WIRES OR CONDUCTORS, AND IN APPARATUS
EMPLOYED THEREIN, PART OF WHICH APPARATUS IS APPLICABLE TO THE MANUFACTURE
OF TUBES FROM INDIA-RUBBER," to be as follows:-
This Invention has for its object improvements in insulating telegraphic
wires or conductors, and in apparatus employed therein, part of which
apparatus is applicable to the manufacture of tubes from india-rubber. In a
Provisional Specification filed by me on the 14th May in the present year,
there is described machinery for covering telegraphic wires or conductors with
india-rubber, and which apparatus consists of two rollers mounted on parallel

page_text: axes, and revolving in contact with each other; each of these rollers is grooved
on its periphery, and the grooves on the two rollers meet, to form an eye of
the size of the covering desired; the grooves in the two rollers are separately
filled with india-rubber, and where the two rollers are in contact, the india-
rubber in the grooves is brought together, so as to form one piece enclosing
the wire or conductor. Now, when a wire or conductor of large size is
employed, I find it desirable to place other or secondary rollers in contact with
the grooved rollers already described, one at each of the points where the
india-rubber is fed into the grooves, and on these secondary rollers are formed
beads, corresponding in size to one-half of the wire or conductor ; these
beads are adjusted so as to fall exactly in the middle of the grooves of the
principal rollers, so that they form indentations in the india-rubber suitable to
receive the wire or conductor; and in some cases I form the conductor by
filling the indentations formed by the beads on the secondary rollers with
metallic powder. These secondary rollers are also of service to press the india-
rubber firmly into the groove of the principal roller. This machine may also
be employed to cover telegraphic wires or conductors with other insulating
compositions; a composition which I have found very suitable for the purpose,
consists of india-rubber or gutta percha combined with shellac by kneading
or mixing the two together, so as to produce a plastic mass. In some cases,
after having coated the telegraphic wires or conductors with this or other
insulating material, I again cover them with gutta percha or other suitable
material with which unspun fibre is ground or intimately mixed. Tubes of
india-rubber may also be formed by machinery, such as that before described,
by forming the grooves in the principal rollers and the beads on the secondary
rollers of a suitable size, and by omitting to introduce a wire or conductor.
Sometimes it is desired to cover telegraphic wires or conductors with gutta
percha or other insulating material, and at the same time to combine yarns
with or imbed them in the covering. For this purpose I employ an apparatus
which consists of a cylinder containing a screw of such a size as just to fit
within it; this screw is mounted on a hollow axis, through which the yarns
and the wire or conductor to be covered pass, and the bobbins from which the
yarns are drawn are mounted on a frame fixed on the end of the same axis;
when the axis is caused to rotate, the gutta percha or other covering material
is pressed out through a die, such as is usually employed, so as to cover the
wire or conductor, and so that the yarns become imbedded in the covering.
When employing more than one coating or covering to a telegraphic wire or
conductor, I cause a current of cold air to impinge on the covered wire or
conductor after the first coating or covering has been applied, so as to bring it

page_text: rapidly to such a consistency that the second coating or covering may be
applied without injuring the first, but without rendering the first coating or
covering so hard or cold as to prevent the complete adhesion of the second-
coating or covering.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Macintosh in the Great Seal Patent Office on the
24th February 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MACINTOSH, of North Bank, Regent's Park, in the County of Middlesex, send.
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of August, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Macintosh, Her special licence that I, the said John
Macintosh, my executors, administrators, and assigns, or such others as I, the
said John Macintosh, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN INSULATING TELEGRAPHIC WIRES OR CONDUCTORS, AND IN APPARATUS
EMPLOYED THEREIN, PART OF WHICH APPARATUS IS APPLICABLE TO THE MANUFACTURE
OF TUBES FROM INDIA-RUBBER," upon the condition (amongst others) that I, the
said John Macintosh, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said John Macintosh, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
This Invention has for its object improvements in insulating telegraphic
wires or conductors, and in apparatus employed therein, part of which

page_text: apparatus is applicable to the manufacture of tubes from india-rubber.
In a Specification of. a Patent granted to me, and dated the 14th May
1858, there is described machinery for covering telegraphic conductors
with india-rubber, and which apparatus consists of two rollers mounted on
parallel axes, and revolving in contact with each other; each of these rollers
is grooved on its periphery, and the grooves on the two rollers meet to form
an eye of the size of the covering desired. The grooves in the two rollers
are separately filled with india-rubber, and where the two rollers are in
contact, the india-rubber in the grooves is brought together, so as to form one
piece enclosing the wire or conductor. Now, when a wire or conductor of
large size is employed, I find it desirable to place other or secondary rollers in
contact with the grooved rollers already described, one at each of the points
where the india-rubber is fed into the grooves, and on these secondary rollers
are formed beads, corresponding in size to one-half of the wire or conductor;
these beads are adjusted so as to fall exactly in the middle of the grooves of
the principal rollers, so that they form indentations in the india-rubber suitable
to receive the wire or conductor.
In carrying out this part of my Invention, I prefer to employ four rollers,
each about one foot in diameter; they are mounted horizontally in a suitable
frame, one over the other, and are geared together so as to run at the same
speed. Steam or other hot fluid is admitted to the interior of each of them,
to maintain the necessary temperature. The two centre rollers have semi-
circular grooves formed in their peripheries, which meeting, form a circular
eye sufficiently large to allow the wire to pass, together with a coating of the
desired thickness; the top and bottom rollers have beads formed on them,
corresponding in size to one-half of the wire or conductor, and adjusted as
before mentioned to fall exactly in the middle of the grooves in the centre
rollers. The india-rubber in the state in which it comes from the masticator
is fed in between the two upper and the two lower rollers, hoppers being
formed at these points to receive it. As the rollers revolve, the india-rubber
is drawn into the spaces between them, these spaces being only those left
between the grooves and the beads before mentioned, and the beads press the
india-rubber firmly into the grooves. The two fillets of india-rubber when
they meet at the eye close over the wire or conductor. This wire or conductor
is drawn from a reel, and passes through a guide placed just before the eye, so
as to keep it truly central; and after being coated, it passes round a drum at
a distance, which revolves at the same surface speed as the covering rollers,
and keeps the wire or conductor taut, or it is otherwise taken away when it is
sufficiently set to bear it. I prefer to apply two or more coatings of india-

page_text: rubber in this manner to the wire, each coating being about 15th of an inch
or less thick, the subsequent coatings being applied by other rollers placed
immediately in front of the first; and for each coating after the first, I employ
top and bottom rollers, having projecting beads on them of progressively
increased size, so as to make indentations in the fillets of india-rubber, which
coming together, leave a space corresponding with the size of the covered
wire receiving the additional coat. In some cases I form the conductor by
filling the indentations formed by the beads on the secondary rollers with
metallic powder. I then prefer somewhat to modify the arrangement of the
apparatus. The two grooved rollers, in place of being mounted one over the
other, are mounted side by side, and the secondary or beaded rollers are of
smaller size, and are placed vertically or nearly vertically over them; this
arrangement admits of a funnel being mounted just over the point where the
fillets of insulating material come together, and this funnel being filled with
metallic powder, pours it into the passage formed by the meeting together of
the grooves, which are produced in the fillets by the beads on the secondary
rollers. The metallic powder which I prefer to employ is that ordinarily
known as bronze powder, and which is metallic copper in a finely divided state.
Telegraphic conductors constructed in this manner are not liable to be injured
by the elongation from heavy strains of cables of which they form part, as is
more or less the case with conductors such as are ordinarily employed.
Tubes of india-rubber may also be formed by machinery, such as that before
described, by forming the grooves in the principal rollers and the beads on
the secondary rollers of a suitable size, and by omitting to introduce a wire or
conductor; or, if preferred, wire coiled spirally may be introduced to strengthen
and support an india-rubber tube.
Machines consisting of grooved and beaded rollers arranged as above
described may also be employed to cover telegraphic wires or conductors wit
other insulating compositions. A composition which I have found very
suitable for the purpose consists of india-rubber or gutta percba combined
with shellac, by kneading or mixing the two together, so as to produce a
plastic mass.
When using soft East India rubber and similar india-rubber, I mix it with
an equal weight of shellac ground to a fine powder, and without the addition
5 of any solvent. The quality of shellac which I prefer to employ being that
known as seed black; and for mixing the india-rubber with the shellac, I prefer
to employ a pair of crushing rollers, between which the india-rubber- after it
has been cleaned in the usual manner is repeatedly passed, and after each
passage through the rollers it is dusted over with the shellac powder, and this

page_text: process is continued until the requisite quantity of shellac has been incorporated
with the india-rubber; the mixture is applied as a covering for telegraphic
conductors in the manner already described. When using india-rubber of a
superior quality to the East India rubber, I employ less shellac, as also when
gutta percha is substituted; in any case, the quantity of shellac should not be
so great as to cause the compound to crack when bent. In some cases, after
having coated the telegraphic wires or conductors with this or other insulating
material, I again cover them with gutta percha, or other suitable material
with which unspun fibre is ground or intimately mixed. For this purpose I
employ cotton waste or other cheap fibre, free from grease;
and by
preference I grind it or tear it to pieces, and afterwards mix it with gutta
percha or india-rubber, by passing the gum repeatedly between crushing
rollers, adding a portion of fibre to it after each passage through the rollers,
until about four pounds of fibre has been worked into a pound of gum; or
the fibre and the gum may be placed together in a machine known as a
masticator, and be mixed by the action of this machine. The composition is
applied as a covering to telegraphic conductors in the manner already
described.
Sometimes it is desired to cover telegraphic wires or conductors with gutta
percha or other insulating material, and at the same time to combine yarns
with or imbed them in the covering. For this purpose I employ an apparatus
which consists of a cylinder, say, one foot in diameter, and two feet long, it is
closed at the ends, and contains a screw of such a size as just to fit within it;
this screw is of about one foot pitch, and is mounted on a hollow axis passing
through the ends of the cylinder; through this axis the yarns and the wire or
conductor to be covered pass, and the bobbins from which the yarns are drawn
are mounted on a frame fixed on the end of the same axis; the cylinder has
an opening in its side near the end, at which the yarns enter for feeding in the
gutta percha or other covering material. When the axis is caused to rotate,
the gutta percha or other covering material is pressed out through a passage
or passages at the end of the cylinder, and it passes into a small box or
chamber furnished at its end with a die such as is usually employed, so as to
cover the wire or conductor, and so that the yarns become imbedded in the
covering. When employing more than one coating or covering to a telegraphic
wire or conductor, I cause a current of cold air to impinge on the covered
wire or conductor after the first coating or covering has been applied, so as to
bring it rapidly to such a consistency that the second coating or covering may
be applied without injuring the first, but without rendering the first coating or
covering so hard or cold as to prevent the complete adhesion of the second

page_text: coating or covering. For this purpose I cause the covered wire or conductor
to pass through a case, through which a current of cold air is forced by a fan,
or otherwise, in the opposite direction to that in which the wire is passing;
this case I make of several feet in length, and of any convenient diameter.
In witness whereof, I, the said John Macintosh, have hereunto set my
hand and seal, this Twenty-fourth day of February, in the year of our
Lord One thousand eight hundred and fifty-nine.
Witness,
AR. CARPMAEL.
JOHN MACINTOSH. (L.S.)