IMPROVE- MENTS IN TANNING, AND IN THE APPARATUS TO BE EMPLOYED THEREIN
Year: 1867

page_text: LETTERS PATENT to Jonas Dawkins, of Pembroke, in the County of
Pembroke, Tanner and Currier, for the Invention of "IMPROVEMENTS IN
"
Sealed the 19th June 1868, and dated the 23rd December 1867.
PROVISIONAL SPECIFICATION left by the said Jonas Dawkins at the
Office of the Commissioners of Patents, with his Petition, on the
23rd December 1867..
3.
I, JONAS DAWKINS, of Pembroke, in the County' of Pembroke, Tanner and
Currier, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN TANNING, AND IN THE APPARATUS TO BE EMPLOYED THEREIN," to bu
as follows:
This Invention relates to certain improvements in tanning whereby the
hides are more rapidly, effectually, and economically tanned than by the '
ordinary methods in use, and also in the apparatus whereby such improve.
ments are effected,
I propose to suspend the hides in covered pits (by preference) by means of
rods fixed in trays or frames, which fit the interior of the pits. These frames
are attached to connecting rods suspended from a rocking beam or beams
balanced in the centre by suitable bearings and shafts, such beam or beams
being caused, to oscillate by steam power or other means, and assuming two
or more pits to be in work the hides are alternately raised and lowered in the
tanning liquor. Other methods of elevating and lowering the hides may
however be adopted. At the bottom of the pits, and to this I attach the

page_text: most importance, I place a plunger or float which may be self-acting in rising,
and caused to fall or descend as the hides are dipped by the beams or other
means; this float may have perforations cut in its surface, so as to cause a
commotion of the liquor by the rush or flow over the edges of the float and
through the apertures or perforations. By these means the tannic acid of the
bark liquor is equally distributed throughout the pits, and consequently every
part of the hide is equally tanned, giving at the same time increased weight
and solidity to the hides.
I also propose to apply, if necessary, to the edges or borders of the plunger
hinged flaps or valves capable of opening one way only, on one side opening
downwards and the other upwards, whereby when the plunger rises the liquor
descends through one side of the plunger and when it descends the liquor
rises through the opposite valve, and consequently a current or continuous
flow of liquor is established, completely tanning the entire hides, the ooze
being thus caused to flow continually between the hides, filling every pore and
converting the bide into leather in a very efficient manner.
I also propose to give motion to the liquor, if necessary, by means of a
vertical scraper or scrapers at one or both ends of the pit. The scraper touches
the bottom of the pit and is connected to an upright rod or bar extending
from the pit, to which rod is attached a lever or handle, and the rod being
set on a joint at the top of the pit the lever will cause it to oscillate and its
lower part or surface will describe an arc of a circle, and I therefore form the
bottom of the vat at one or both ends of a corresponding curve, so that the
sediment of the liquor will continually be moved or stirred, thus causing all
portions of the liquor to be equally supplied with tannic acid.
I also propose to increase the commotion of the liquor by a blast of air,
which is caused to enter the lower part of the pits by pipes in connection
with a blowing fan or other appliance for creating a blast; and in order to
convey the air to any particular pit or pits from the fan or other blower I
arrange an air vessel or receptacle at any suitable position, and place therein
a cylinder perforated with a series of openings, which are brought to corre-
sponding apertures in a semi-cylindrical side of the vessel, so that the air being
brought into the cylinder from the blowing machine may then be conveyed to
any desired pit by turning the cylinder till the proper opening comes opposite
that in the vessel to which the pipe is attached from such pit. By this
arrangement one blower is sufficient for all the pits. A throttle valve should
be applied to the pipe between the air chamber and blower for the purpose
of regulating the supply of air.
In some cases, where the oxygen of the air acting on the tannic acid may

page_text: be considered detrimental to the tanning liquor by converting the tannic into
gallic acid, I propose to reconvey the air to the blower,, which should then be
enclosed in an air-tight chamber or cylinder. This reconveyance of the air
may easily be effected by means of return pipes from the covered pits to the
blower, the rod which actuates the hides being passed through a stuffing box
in the cover; or if desired the air may be.deprived of its oxygen by any of the
well-known means prior to its being injected by the blower into and through
the liquor.
I also propose to supply a blast of any other suitable gaseous nature capable
of causing commotion in the liquor without giving oxygen to the tannic acid,
the principle being the same.
I also propose to utilize the waste bark dust from the grinding process
which escapes and is lost by drawing the same into suitable receptacles or
chambers by a revolving fan causing exhaustion of; air, whereby the particles
of the bark dust are collected and forced with the air or other gaseous
elements into the tanning liquor.
I am aware that the see-saw principle, of elevating and lowering hides is
not new, but in conjunction with the means of effecting commotion of the
liquor herein described it is novel.
I can use my methods of effecting commotion, and thereby thoroughly,
completely, and efficiently tanning the hides, without moving the hides if I
prefer to do so, since the plunger or float may be moved up and down by any
suitable power. and connecting rods or other attachments.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Jonas Dawkins in the Great Seal Patent Office on the
23rd June 1868.
-
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JONAS
DAWKINS, of Pembroke, in the County of Pembroke, Tanner and Currier,
send greeting."
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of December, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirty-first year of
Her reign, did for. Herself, Her heirs and successors, give and grant unto me,
the said Jonas Dawkins, Her special licence that I, the said Jonas Dawkins,
my executors, administrators, and assigns, or such others as I, the said
Jonas Dawkins, my executors,, administrators, and assigns, should at any

page_text: 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
TANNING, AND IN THE APPARATUS TO BE EMPLOYED THEREIN," upon the condition
(amongst others) that I, the said Jonas Dawkins, my executors or adminis-
trators, 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 Jonas Dawkins, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
:
My Invention relates to certain improvements in tanning whereby the
hides are more rapidly, effectually, and economically tanned than by the
ordinary methods in use, and also in the apparatus whereby such improvements
are effected..
I suspend the hides in covered pits (if I prefer to do it) by means of rods
fixed in trays or frames which fit the interior of the pit. These frames are
attached to connecting rods suspended from a rocking beam or beams balanced
in the centre by suitable bearings and shafts, such beam or beams being
caused to oscillate by steam power or other means, and assuming two or
more pits to be in work the hides are alternately raised and lowered in the
tanning liquor. At the bottom of the pits (and to this I attach the most
importance) I place a plunger or float which may be self-acting in rising,
and caused to fall or descend by any suitable movement, or as the hides are
dipped by the beam or other means; this float may have perforations cut in
its surface, so as to cause a commotion of the liquor by the rush or flow
over the edges of the float and through the apertures or perforations. By
these means the tannic acid of the bark liquor is equally distributed through-
out the pits, and consequently every part of the hide is equally tanned, giving
at the same time increased weight and solidity to the hides. :
I also apply, if necessary, to the edges, borders, or other parts of the
plunger hinged flaps or valves capable of opening one way only, on one side
opening downwards and the other upwards, whereby when the plunger rises,
the liquor descends through one side of the flap or valve, and when it descends
the liquor rises through the opposite flap or valve, and consequently a

page_text: 4
current or continuous flow of liquor is established; the ooze or liquor being
thus caused to flow continually between the hides filling every pore, and
converting the hide into leather in a very efficient manner.
I also give motion to the liquor (if necessary) by means of a vertical scraper
or scrapers, sliding or otherwise; at one or both ends or other parts of the pit;
the scraper touches the bottom of the pit, and is connected to an upright rod
or bar extending from the pit, to which rod is attached a lever or bandle, and
the rod being set on a joint at the top or other part of the pit, the lever will
cause it to oscillate, and its lower part or surface may describe an arc of a
circle or otherwise, and I therefore form the bottom of the vat at one or both
ends of a corresponding curve, if necessary, so that the sediment of the liquor
will continually be moved or stirred, thus causing all portions of the liquor to
be equally supplied with tannic acid.
I also increase the commotion. of the liquor, if necessary, by a blast of air
which is caused to enter the lower part of the pits by pipes in connection with
a blowing fan or other appliance for creating a blast; and in order to convey
the air to any particular pit or pits from the fan or other blower, I arrange an
air vessel or receptacle at any suitable position, and place therein. a cylinder
perforated with a series of openings, which are brought to corresponding
apertures in a semi-cylindrical side of the vessel, so that the air. being brought
into the cylinder from the blowing machine may then be conveyed to any
desired pit by turning the cylinder till the proper opening comes opposite that
in the vessel to which the pipe is attached from such pit. By this arrangement
one blower is sufficient for all the pits. A throttle valve should be applied to
the pipe between the air chamber and blower for the purpose of regulating
the supply of air.
,
In some cases where the oxygen of the air acting on the tannic acid may
be considered detrimental to the tanning liquor by converting the tannic into
gallic acid, I reconvey the air to the blower, which should then be enclosed
in an air-tight chamber or cylinder; this reconveyance of the air may easily
be effected by means of return pipes from the covered pits to the blower; the
rod which actuates the hides being passed through a stuffing box in the cover.
Or, if desired, the air may be deprived of its oxygen by any of the well-known
means prior to its being injected by the blower into and through the liquor.
I also in some cases supply a blast, if necessary, of any other suitable
gaseous nature capable of causing commotion in the liquor without giving
'oxygen to the tannic acid, the principle being the same.
I also in supplying a blast for causing commotion utilize the waste bark
dust from the grinding process which escapes and is lost, by drawing the

page_text: .
same into suitable receptacles or chambers by a revolving fan or other means,
causing exhaustion of air, whereby the particles of the bark dust are collected
and forced with the air or other gaseous elements into the tanning liquor.
Instead of using troughs or gutters carried along under the pits or tan yards,
I connect pit to pit internally by means of connecting troughs, gutters, or
pipes, plugs, stop-cocks, or valves, or any other suitable means conveniently
arranged for letting off or stopping liquor, whereby the pumping will be
reduced to one half throughout the yard.
I am aware that the see-saw principle of elevating and lowering bides is
not new, but in conjunction with the means of effecting commotion of the
liquor herein described it is novel; this latter operation being of essential
service, and constituting the principal part of this Invention.
I can use my methods of effecting commotion, and thereby thoroughly,
completely, and efficiently tanning the hides, without moving the hides, if I
'prefer to do so, since the plunger or float, scraper or scrapers, may be moved
"up and down, or oscillated by any suitable power and connecting rods or other
attachments, or by a blast.
Having now described the nature of my said Invention, and the manner in
which the same is to be performed, I would remark that I do not limit myself
to any definite configuration of apparatus to be employed, as the same may be
varied to suit different requirements; but what I claim and desire to be
secured to me by the herein in part recited Letters Patent are, the methods
and apparatus whereby I cause commotion of the tanning liquor in which the
Lides are immersed; or moving them in the liquor, if I prefer to do so, by
means of the see-saw. arrangement; or leaving them stationary in the liquor,
if I prefer to do so; the method of utilizing the waste bark dust, and the
method of connecting pit to pit internally, all substantially as and for the
purposes herein specified.
In witness whereof, I, the said Jonas Dawkins, have hereunto set my
hand and seal, this Eighteenth day of June, in the year of our Lord
One thousand eight hundred an1 sixty-eight.
Witness,
JOHN ORMOND,
Chemist,
Pembroke.
JONAS DAWKINS. (L.S.)