IMPROVEMENTS IN THE MANUFACTURE OF OAKUM, AND IN THE APPARATUS EMPLOYED THEREIN
Year: 1867

page_text: LETTERS PATENT to John Eliot Hodgkin, of Liverpool, in the County of
Lancaster, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
OAKUM, AND IN THE APPARATUS EMPLOYED THEREIN."
Sealed the 15th October 1867 and dated the 16th April 1867.
PROVISIONAL SPECIFICATION left by the said John Eliot Hodgkin
at the Ollice of the Commissioners of Patents, with his Petition, on the
16th April 1867.
THE
1, JOHN ELIOT HODGKIN, of Liverpool, in the County of Lancaster, do
hereby declare the nature of the said Invention for "IMPROVEMENTS
MANUFACTURE OF OAKUM, AND IN THE APPARATUS EMPLOYED THEREIN," to be as
follows:
The object of this Invention is to prepare oakum from untarred or in-
sulliciently tarred fibre such as tow obtained from white or other ropes or the
shorts from dressing hemp, or fibres derived from other sources, by impregnating
it with a solution of tar in a suitable solvent more easily evaporated than the
tar, and then driving off and again collecting the volatile solvent employed
if desired. The solvent which I have found most advantageous hitherto for
this purpose has been benzole, but other light oils of coal tar, or the light
oils derived from petroleum, bisulphide of carbon, or wood naptha, may be
employed in carrying out any Lavention. The simplest mode of applying the
tar in solution is to steep the fibre in a mixture made by dissolving tar, either
cold or at a higher temperature in any of the above-named solvents, and then
placing it in a close vessel, and driving off the vapour of the solvent into a still
so as to collect it for future use.

page_text: The apparatus which I prefer to employ in carrying out my Invention is
the following-In order to prepare the solution of tar for impregnating tow
or other fibre according to my Invention proper proportions of tar and solvent
are introduced into a suitable mixing vessel which may be heated, if desired,
by steam, or in any other suitable manner. A shaft or axis furnished with
knives or beaters passes through the mixing vessel and is supported in bear-
ings exterior thereto. The mixing vessel can either be made to revolve
rapidly, the shaft and knives being stationary, or vice versa, the object being
thoroughly to dissolve the tar without waste of the solvent by evaporation.
When thoroughly mixed the solution is allowed to flow into another vessel in
which by filtration (under pressure or otherwise, or by settling) the small
insoluble portion of the tar (if any) is separated from the clear liquor. The
tow or other fibre obtained either by teasing and opening white or other ropes,
or the shorts resulting from dressing hemp, or from any other suitable source,
is placed in a steam jacketted chamber. the manhole joint being then made
tight; this chamber is then filled with the tar liquor, steam being admitied
into the jacket in order to heat the tow and liquor, and thus thoroughly
impregnate the tow. If desired a piston may be arranged in the vessel and
be caused to descend so as to squeeze the liquor out of the tow into a space
arranged under a grating or false bottom in the inner impregnating chamber.
The draining of the tar liquor from the tow or fibre in the impregnating vessel
is usually all that is required unless it is desired to facilitate the process by
pressure. When the tow is sufliciently free from the tar liquor the steam is
turned off and the superfluous liquor is allowed to flow into a receiver. Hot
air, steam (superheated or otherwise). is then admitted again to the jacket
around the impregnating chamber. by which means the solvent which held
the tar in solution is driven off into a still and there condensed by cold water
or recovered in any other suitable manner. The tow is now evenly saturated
with tar and contains an inappreciable quantity of the solvent, it can then be
removed from the impregnating chamber, which is cooled with cold water
ready for receiving the next batch of fibre a few hours exposure to a current
of warm air renders the oakum fit for market, and it can be finally carded if
desired. The superfluous tar liquor is discharged from the impregnating
vessel into a receiver, which is a closed vessel into which a pipe from a con-
densing pump is taken, and from the bottom of which a pipe rises to the
mixing vessel. By the application of pressure the liquor is driven up into the
mixing vessel again; the distilled solvent from the still also runs into the same
mixing vessel by gravitation, and all that is required to prepare the apparatus
for the next operation is to add as much tar as the previous batch of tow has

page_text: taken up together with any slight loss of solvent which may have taken place.
Warm air may be forced or drawn through the impregnated fibre after its
saturation by any suitable means, the air being arranged to pass over with the
vapour into the still.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Eliot Hodgkin in the Great Seal Patent Office on the
15th October 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, 1, JOHN
ELIOT HODGKIN, of Liverpool, in the County of Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of April, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of
Her reign. did. for Herself. Her heirs and successors. give and grant unto
me, the said John Eliot Hodgkin, Her special licence that 1, the said
John Eliot Hodgkin. my executors, administrators, and assigns, or such
others as I. the said John Eliot Hodgkin, 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 "IMPROVEMENTS IN THE MANUFACTURE OF OAKUM. AND IN THE
APPARATUS EMPLOYED THEREIN," upon the condition (amongst others) that I
the said John Eliot Hodgkin, executors or administrators, by en instru-.
ment 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Eliot Hodgkin, 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:-
The object of this Invention is to prepare oakum from untarred or
insufficiently tarred fibre, such as low obtained from white or other ropes or
the shorts" from dressing hemp or fibres derived from other sources by
impregnating it with a solution of tar or tar dissolved in a suitable solvent,

page_text: the latter being more easily evaporated than the tar, and then driving off
and again collecting the volatile solvent if desired. The solvent which
I have found most advantageous hitherto for this purpose has been benzole,
but other light oils of coal tar or the light oils derived from petroleum,
bisulphide of carbon or wood naptha may be employed in carrying out my
Invention. The simplest mode of applying the tar in solution is to steep the fibre
in a mixture made by dissolving tar either cold or at a higher temperature in any
of the above-named solvents, and then placing it in a close vessel and driving
off the vapour of the solvent into a still so as to collect it for future use.
The apparatus which prefer to employ in carrying out my Invention is the
following-In order to prepare the solution of tar for impregnating low or
other fibre according to my Invention, the tar and solvent (in such proportions
that when dissolved the solution will be sufliciently fluid as to readily saturate
or impregnate the tow or other vegetable fibres introduced into it with the
desired amount of (ar) are introduced into a suitable mixing vessel which
may be heated if desired by steam or in any other suitable manner. A shaft
or axis furnished with knives or beaters passes through the mixing vessel
and is supported in bearings exterior thereto. The mixing vessel can either
be made to revolve rapidly, the shaft and knives being stationary or vice versa,
the object being thoroughly to dissolve the tar without waste of the solvent
by evaporation when thoroughly mixed the solution is allowed to flow into
another vessel in which by filtration (under pressure or otherwise or by
settling), the small insoluble portion of the tar (if any) is separated from the
clear liquor. The tow or other fibre obtained either by teasing and opening
white or other ropes, or the shorts resulting from dressing hemp or from any
other suitable source is placed in a steam jacketted chamber, the man-hole
joint being then made tight; this chamber is then filled with the tar liquor,
steam being admitted into the jacket in order to heat the tow and liquor, and
thus thoroughly impregnate the tow. If desired a piston may be arranged
in the vessel and be caused to descend so as to squeeze the liquor out of the
low into a space arranged under a grating or false bottom in the inner
impregnating chamber. The draining of the tar liquor from the tow or fibre
in the impregnating vessel is usually all that is required unless it is desired
to facilitate the process by pressure. When the tow is sufliciently free from
the tar liquor the steam is turned off and the superfluous liquor is allowed to
flow into a receiver; hot air or steam is then admitted again to the jacket
around the impregnating chamber, by which means the solvent which
the tar in solution is driven off into a still, and there condensed by cold water
or recovered in any other suitable manner. The tow is now evenly saturated

page_text: with far and contains an inappreciable quantity of the solvent; it can then
be removed from the impregnating chamber which is cooled with cold water
or otherwise ready for receiving the next batch of fibre: a few hours exposure
to a current of warm air renders the oakum fit for market and it can then
be finally carded if desired. The superfluous tar liquor is discharged from
the impregnating vessel into a suitable receiver or closed vessel connected
by a pipe with an air condensing or force pump, and from the bottom of the
closed vessel or receiver a pipe rises to the mixing vessel, so that by the
application of pressure to the closed vessel or receiver by the action of the
pump, the liquor is driven up into the mixing vessel again. The distilled
solvent from the still also runs into the same mixing vessel by gravitation,
and all that is required to prepare the apparatus for the next operation is to
add as much tar as the previous batch of tow has taken up together with any
slight loss of solvent which may have taken place. Warm air may be forced
or drawn through the impregnated fibre after its saturation by any suitable
means, the air being arranged to pass over with the vapour into the still, in
which case the use of the steam jacket may be dispensed with in this part of
the process.
Having thus described the nature of my Invention, and the manner in
which the same is to be performed or carried into practice, I would have
it understood that I do not confine myself to the exact details herein described
so long as the novel characier of my Invention is retained; what I claim is,
the manufacture of oakum from untarred or insufficiently tarred tow or
other vegetable fibrous materials by impregnating the same with a solution
of tar by the means, apparatus, and processes employed in the manner herein
described, or by any similar modification thereof.
In witness whereof, I, the said John Eliot Hodgkin, have hereunto set
my hand and seal, this Tenth day of October, in the year of our Lord
One thousand eight hundred and sixty-seven.
Witness,
J. G. TONGUE,
Patent Agent,
JOHN ELIOT (L.S.) HODGKIN.
34, Southampton Buildings,
Chancery Lane, W.C.