IMPROVEMENTS IN TANNING AND IN THE MANUFACTURE OF LEATHER, AND IN MACHINERY ADAPTED THERETO
Year: 1859

page_text: LETTERS PATENT to John Eason, of Oxford Street, in the County of
Middlesex, for the Invention of "IMPROVEMENTS IN TANNING AND IN THE
MANUFACTURE OF LEATHER, AND IN MACHINERY ADAPTED THERETO."
Sealed the 29th June 1860, and dated the 31st December 1859.
PROVISIONAL SPECIFICATION left by the said John Eason at the
Office of the Commissioners of Patents, with his Petition, on the 31st
December 1859.
I, JOHN EASON, of Oxford Street, in the County of Middlesex, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN TANNING, AND
IN THE MANUFACTURE OF LEATHER, AND IN MACHINERY ADAPTED THERETO," to be
as follows:-
I propose constructing tanks of iron (lined with any suitable material) of B
cylindrical form with circular dished ends, and of sufficient strength to bear
the required pressure, the top end being detached, and when in use is to be
secured by drop screw bolts working on centres or hinges under the flange of
the tank, this cover is removed by a small crane fixed to the side of the tank.
An outlet is made at the bottom of the tank, to which is attached a metal
pipe, at the end of which is a safety pressure valve, which opens by the action
of a spiral spring within, which can be set at any required pressure, the pres-
sure being maintained within the tank while the spent liquor is escaping
through the valve. The interior of the tank is fitted with a centre metallic
spindle or shaft working in a bridge or socket at bottom, and through a stuffing

page_text: box at top, on the upper part of which is fixed a metal hoop having wooden
cross rails dropped into notches for their reception. Another similar hoop
being made to slide up and down beneath the former one to any required
height by a screw nut, so that perfect isolation of the skins may be obtained
by hanging them between the upper and lower rails. The hoops with the
skins are made to rotate by means of an endless screw and spur wheel to be
worked either by hand or steam power.
The process of tanning butts and other stout leathers in the before-
mentioned machine is as follows:-The hides or skins after unhairing in
the usual manner are suspended on the rails; the lime is then extracted by
exhaustion in or out of solution with warm or cold water, or a warm
solution of alum and water when necessary, after which the process of
tanning is commenced with weak oak bark liquor, changing and increasing in
strength daily. The liquor is applied by exhausting the air from the top of
the tank, and through a hose attached to the valve at the bottom the liquor
rushes up, thus filling the pores of the skin previously opened by exhaustion.
If only a common tap or valve is used instead of the before-mentioned one,
then it is left open just sufficient to allow of the escape of the same quantity
of liquor as is admitted by each stroke of the hydraulic pump. By this means
the spent liquor is forced out of the skins and replaced by fresh, which is
repeated daily until the operation of tanning is thoroughly completed. To
facilitate the process of tanning in cold weather and to prevent the evil effects
of frost, I keep the liquor at a heat of about 70° Fahrenheit, or blood heat,
by having a small metal pipe laid in rows or coils at the bottom of the tank
through which the waste steam from the engine is allowed to pass.
For the manufacture of calf or upper leather, I suspend the skins in the
tanks (after lining and flesbing) in warm or cold water; the lime is then
extracted, after which the air is exhausted from the hides either in or out
of solution. The tank is then filled up with a warm solution of bran and
water, or when necessary alum and water, and the skins allowed to remain in
for about two days exhausting them occasionally in the meantime, after which
they are to be placed in weak oak coppice bark liquor or other suitable tanning
material, gradually increasing the strength daily as above described.
For extracting the liquors I use a machine of the following construction :--
A wooden tank of an oblong or other suitable form, and of convenient size is
fitted with a close cover and centre stuffing box for the purpose of retaining
the heat and preventing evaporation; within the tank is a moveable frame or
inner tank with a perforated zinc bottom, upon which I place the bark or
other material from which the virtue is to be extracted; one side of the same

page_text: is hinged at bottom to drop down and let out the exhausted material. The
framework or inner tank is attached to a rod or shaft working through the
stuffing box above, on which is a double rack in a frame with a pinion between
having teeth on only one part of its periphery, or other suitable contrivance
calculated to give the upward and downward motion required. At the
bottom of the tank beneath the perforated zinc bottom are fixed "fish bone"
perforated pipes, through which the waste steam from the boiler circulates,.
keeping the material and liquor at a heat of about 200° Fahrenheit..
For the purpose of fleshing and shaving. I employ an oblong iron framing,
on which is a currying knife fixed to a semicircle, which moves in a groove,
and fixed with a set screw so as to set it to any angle; this travels on the
top of the frame over the skin, which is placed upon a moveable table
beneath, so that the knife acts on the skin like a plane. The table may be
moved to the right hand or left by means of a lever and toothed wheel, into
which drops a pall, the end of the lever having a weight attached, which
acts as a spring to keep the table in position.
For the manufacture of losh or oiled leather, I employ the same description
of tank as that for tanning, isolating the skins and pumping the oil in a warni
state. The skins are to be repeatedly taken out and beaten with wooden.
notched beaters, and then subjected to pressure, after which they are to be
finished in the usual manner.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Eason in the Great Seal Patent Office on the 30th
June 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN EASON,
of Oxford Street, in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Pateut, bearing date the Thirty-first day of December, in the year of our
Lord One thousand eight hundred and fifty-nine, in the twenty-third year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said John Eason, Her special licence that I, the said John Eason,
my executors, administrators, and assigns, or such others as I, the said John
Eason, 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

page_text: Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN TANNING, AND
IN THE MANUFACTURE OF LEATHER, AND IN MACHINERY ADAPTED THERETO," upon
the condition (amongst others) that I, the said John Eason, my exc-
cutors 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 Eason, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, that is to say:-
One part of my said Invention consists of certain machinery and a process
hereafter described which I have invented for the purpose of tanning leather
more perfectly and expeditiously.
F
The machinery or apparatus which I use for the purpose of tanning hides or
skins according to my said Invention consists of a tank or vessel in which
hides or skins are suspended during the process of tanning hereinafter described.
This tank or vessel is capable of being closed and made air and water tight,
and of sufficient strength to bear the exhaustion of the air from it, and a
considerable amount of pressure when tanning or other liquor is forced into it,
in tanning or operating upon hides or skins for manufacturing leather
according to my Invention. This tank or vessel is also constructed so that
rotary motion may be given to the apparatus upon which the hides or skins.
are suspended within it; such rotary motion is produced by suitable machinery,
and the air is exhausted from the tank or vessel, and the liquid is forced into
it by pumps or machinery suitable for effecting those objects.
I propose to construct the tanks or vessels to be used in tanning hides or
skins according to my Invention of iron (lined with any suitable material for
preventing injury to the liquor or skins) of a cylindrical form with circular
dished ends, and of sufficient strength to bear the required pressure, the top and
or cover being capable of being detached, and, when in use, secured to the vessel
by screws or other suitable means.
I will, with the aid of the accompanying Drawings, proceed to describe the
mode in which I prefer to construct such a tank or vessel, and the apparatus
connected with it.
In these Drawings, Figure 1 is a vertical section of a tank and apparatus
connected with it, for the purpose of tanning according to my Invention;

page_text: Figure 2 is a plan or top view of the upper end of the tank when the
top or cover has been removed, shewing the rails upon which the hides or
skins are suspended; and Fig. 3 shews a portion of the cross-bar placed across
the tank, together with one of the two pairs of arms at the ends of such cross-
bar for supporting the ring carrying the laths or rails upon which the hides or
skins are suspended. In these Figures similar parts are marked with similar
letters of reference.
a, a, a, is a cylindrical tank, which I prefer to make with internal vertical
ribs Z, Z, shewn in Figure 2, in order to cause currents of liquor in various
directions within the tank to be produced by the rotary motion given to the
skins and liquor within the tank, and by the liquor being thus caused to flow
against the ribs. The tank has a dished bottom a', a', and the top or cover
y, y, is of a form somewhat similar to the bottom, but capable of being
detached when in use. The top or cover is secured to the tank by drop screw
bolts c attached to hinges under the flange of the tank. The cover is removed
from the tank by means of a small crane or derrick d, d, attached to one side
of the tank. An outlet is made in the centre of the bottom of the tank, which
is connected with a pipe having a stop-cock at its outer end, the cock being
constructed so that a pipe communicating with a reservoir of liquor may be
attached to it. The interior of the tank is fitted with a vertical metallic
spindle or shaft e, e, working in a fixed bridge or step f over the outlet at
bottom and also working in a bush or bearing in the cross-picco a, x, herein-
after mentioned. This shaft is placed in the centre of the tank, and it has
attached to it near its upper end within the tank, a cross-bar r, having at
each end a pair of segmental arms t, t, (as shewn in Figure 3) for supporting
the ring or hoop 9, 9, and the arms t, t, are secured by screws to the inside
of the ring 9, 9, for carrying the rails shewn in Figure 2. The ring 9, g,
consists of an external hoop of brass lined with wood, in which notches are
made to receive the ends of the laths or rails S, upon which the hides or skins
are to be suspended. This ring is supported by the segmental arms t, t, at
the end of the cross-bar r, shewn in Fig. 8, and the centre of the cross-bar is
secured upon the vertical shaft c, e, so as to be carried round with the shaft
when rotary motion is given to it. A cross-piece X, X, having a bush or
bearing in its centre of a proper size to receive the vertical shaft e, e, is secured
by screws or otherwise to the sides of the tank, and this cross piece is secured
in its proper position before putting on the lid of the tank in order to keep the
upper end of the shaft e, e, in its proper position. A short shaft i works in a
stuffing box 0, 0, in the lid or cover of the tank; this short shaft bas at its
lower end a square socket made to fit upon the upper end of the shaft c, e,

page_text: which is made square to fit the socket, and the short shaft i has a worm wheel
fixed upon the top of it so as to have rotary motion given to it by an endless
screw, or such motion may be given to it in any other convenient manner.
When rotary motion is given to the short shaft i, the vertical shaft e, e, is
also caused to turn round, and the latter shaft carries round with it the cross-
bar r, ring 9, 9, and the laths or rails and the skins suspended upon them
within the tank. In the lid or cover y, y, is fixed a pipe p, through which
the air in the tank may be exhausted from it, and this pipe is furnished with
a stop-cock, by which it can be closed when not in use. In the lid is alsó fixed
another pipe w through which tanning liquor may be forced into the tank, and
this pipe is also furnished with a stop-cock. Each of these cocks are made so
as to be capable of being connected with an air pump or a force pump.
Tanning of sole, harness, and other leathers in the beforo described machine is
performed as follows:-The hides or skins after being unhaired in the usual
manner are suspended on the laths or rails S, S, within the tank, the cross-
piece X, X, is then secured in its place, and the lid or cover y, y, is placed upon
the top of the tank and secured by means of the drop screws c, with the socket
at the foot of the short shaft i embracing or upon the top of the shaft e, c, as
shewn in Fig. 1. When required the lime may be extracted from the hides
or skins by exhaustion in the tank or by any other process which can
be conveniently performed within the tank. This I prefer to perform in the
following manner, but which does not form part of my present Invention (that
is to say) I first exhaust the air from the vessel, and then let in the water.
By the exhaustion the lime will be brought to the surface of the skins, and the
water being then suddenly let in will wash them thoroughly, thus dispensing
with the ordinary disagreeable method of "graining," bateing," and purcing."
The extraction of the lime from skins in this or in any other manner
before commencing the process of tanning prevents the destruction of the first
tanning liquor applied to the hides which would be caused by the lime in the
skins if not previously extracted by exhaustion or otherwise. The skins being
placed in the tank as already mentioned, and in a fit state to be tanned, the
process of tanning is commenced with oak bark liquor or other tanning liquor
changing and increasing the strength from time to time in the usual way.
The liquor is first introduced by exhausting the air from the tank and through
the pipe in the lid or cover, and upon opening the tap in the pipe
at the bottom of the tank, which is made to communicate with a reservoir
containing the tanning liquor, the liquor rushes up through that pipe into the
tank, filling the pores of the skins previously opened by exhaustion. After the
liquor has been thus introduced I proceed to force a stream of liquor into the

page_text: .
tank through the pipe w in the lid, which pipe is connected with a force pump
or any other convenient apparatus having the requisite power to force the
liquor into the tank in such a way as to keep up a considerable pressure
within the tank which I find may usefully be from thirty to one hundred lbs.
to the square inch.
Whilst this is going forward I open the tap in the pipo at the bottom of the
tank to such an extent as to allow a stream of liquor to escape equivalent or
nearly equivalent to that which is forced into the tank at the top the quantity
forced into the tank at the top being sufficient not only to supply the place of
that which escapes at the bottom, but also to keep up the intended pressure
within the tank. In this way I cause a constant stream of the tanning liquor
employed to pass through the tank during the process of tanning, (increasing
the strength of the liquor from time to time as before mentioned,) so that the
skins or hides, by the rotary motion given to them within the tank and the
motion of the liquor in passing through the tank, have their surfaces con-
tinually brought into contact with fresh portions of the liquor, so that by
means of such motion and the pressure which is kept up within the tank, the
operation of tanning the hides or skins may be more thoroughly and speedily
effected. The only difference between the mode of treating stout hides or
skins and the treatment of calf skins or other thin skins has reference to the
preparation of the skins for undergoing the process of tanning and the
different modes of preparing those classes of hides and skins for being tanned
are well known, and form no part of my Invention.
Another part of my said Invention consists of a machine for extracting or
preparing the liquors used in tanning. This machine consists of a wooden
tank of an oblong, square, or other suitable form and convenient size fitted
with a close cover for the purpose of retaining the heat, and proventing loss by
evaporation. Within the tank is a moveable frame or tray with a perforated
bottom, upon which I place the bark or other materials from which this
tanning material is to be extracted by water; the lower end of a piston rod is
fixed to the centre of the tray, and this rod passes through a stuffing box in
the centre of the cover. By means of this rod the tray within the tank is
alternately raised and lowered during the process of preparing the liquor.
One side of the tray is made moveable upon hinges at the bottom so as to be
capable of being let down when required, in order to remove exhausted
material from the tray.
The mode in which I prefer to construct this tank, and the apparatus con-
nected with it, is shewn in Figure 4 of the annexed Drawing. The tank or
vessel A, A, A, is made of wood, and has a cover B, B, which may be sécured

page_text: to the top of the tank in any convenient manner.
Within the tank is a tray
or open box H, HI, the bottom of which is made of wooden frames with per-
forated zinc covering the openings in the framework. The sides are made of
deal perforated with holes, and the side 9 is furnished with hinges at the
bottom so as to be capable of being turned down when the tray is taken out
of the tank, but when in the tank the side q is secured in a vertical position
to the other side of the tray or box. K, K, is a vertical piston, the bottom
of which is fixed to the centre of the tray or box; this piston passes up
through a stuffing box N, N, in the cover of the tank. The upper part of the
piston is threaded with a screw, and passes up through a beam D, D, above
which the screw on the piston is furnished with a nut, by means of which the
tray may be raised out of or lowered into the tank. In the middle of the
piston is a frame M, M, containing two racks m, m, one on one side of
the frame and the other rack on the other side. A pinion R is furnished with
teeth upon a portion of its periphery, which are of a proper size to take into
the teeth of the racks m, m. This pinion is mounted in suitable bearings
(not shewn in the Figure), and by its revolution it alternately raises and
lowers the piston and with it the tray within the tank. When the tray is to
be raised out of the tank the pinion R is removed out of the way. The up
and down motion of the piston and tray may be produced in any other manner
which may be deemed convenient. At the bottom of the tank are fixed a
series of "fish bone" perforated pipes, through which steam from a boiler
(which I prefer should be superheated) passes into the liquor so as to keep
up the heat to the required temperature, which I prefer to make about 200°
of Fahrenheit's thermometer.
When oak bark or other material intended to be used in making a tanning
liquor, has been placed in the tray II, H, the requisite quantity of water is to
be put into the tank and the cover secured. The steam is then to be turned
on so as to heat or keep up the temperature of the liquor, and motion is to
be given to the pinion R so as to produce a continual up and down motion of
the tray and the material upon it, and thus subject the material operated upon
more thoroughly to the action of the hot water, and obtain as much extract as
practicable from it.
Having now particularly ascertained and described the nature of my said
Invention, and the manner in which the same is to be performed, I wish it to
be understood that I do not claim, as of my said Invention, any of the
mechanical elements or parts above mentioned or described, and of which my
improved machinery is comprised, apart or separate from the combination or
application in the construction of such machinery, nor do I claim either the

page_text: application of pressure to tanning liquor or skins during the process of tanning,
or the moving of skins in tanning liquor during the operation of tanning as
being separately any part of my said Invention; but what I do claim, as my
Invention, is,
Firstly, the peculiar arrangement of machinery for the purpose of tanning
hides and skins in the manufacture of leather, as herein described.
Secondly, the mode of subjecting hides and skins during the process of
tanning to the continual action of tanning liquor in motion and under
pressure, and with the skins also in a state of motion, as herein described.
And, thirdly, the mode of constructing and combination of parts constituting
the machine herein-before described for applying heat and motion to water
and tanning material during the process of making tanning liquor, as herein-
before described.
In witness whereof, I, the said John Eason, have hereunto set my
hand and seal, this Twenty-ninth day of June, in the year of our
Lord One thousand eight hundred and sixty.
JOHN EASON.
(L.S.)
Witness,
S. J. WETHERELL,
Clerk to Messrs. Prince & Co.,
Patent Agents,
4, Trafalgar Square, Charing Cross.