CERTAIN IMPROVEMENTS IN TANNING
Year: 1823

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
GYBBON SPILSBURY, of Walsall, in the County of Stafford, send greeting.
WHEREAS His most Excellent Majesty King George the Fourth, did,
by His Letters Patent under the Great Seal of His United Kingdom, bearing
date at Westminster, the Twenty-second day of April, 1828, in the fourth
'year of His reign, give and grant unto me, the said Francis Gybbon
Spilsbury, my exors, adiñors, and assigns, His especial licence, full power,
sole privilege and authority, that I, the said Francis Gybbon Spilsbury,
my exors, adñiors, and assigns, during the term of years therein mentioned,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "CERTAIN
IMPROVEMENTS IN TANNING;" in which said Letters Patent there is contained
a proviso, that if I, the said Francis Gybbon Spilsbury, shall not particularly
describe and ascertain the nature of my said Invention, and in what manner
the same is to be performed by an instrument in writing under my hand
and seal, and cause the samo .to be inrolled in His Majesty's High Court
of Chancery within six calendar months next and immediately after the
date of the said Letters Patent, that then the said Letters Patent and all
liberties and advantages whatsoever thereby granted, shall utterly cease,
determine, and become void, as in and by the same, relation being thereunto
had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
I, the said Francis Gybbon Spilsbury, do hereby declare that the nature of

page_text: my said Invention, and the manner in which the same is to be performed,
are particularly described and ascertained in and by the Drawing hereunto
annexed, and the following description thereof (that is to say):-
My improved method of tanning skins or hides consists in the application
of mechanical force by means of certain machines or apparatus, for the
purpose of driving the tan liquor or liquors through the skins or hides
intended to be tanned. The skins or hides, in the usual method of tanning,
after they have been prepared by liming, and other well known processes, are
immersed in the tan liquor or liquors. In this situation they absorb, or
are penetrated by a portion of the liquor in which they are immersed. This
portion having produced on the skin or hide its tanning effect, becomes more
or less exhausted, and as long as it remains in the skin or hide, greatly
retards the entrance therein of fresh portions of unexhausted tan liquor, and
thus protracts to a very inconvenient length the tanning process, especially
when applied to dense skins or hides.
.
My Invention consists in the introduction of the tan liquor by means of
mechanical force into the pores or substance of the skin or hide, which I effect
in the following manner:-The skin or hide being cleansed and otherwise
prepared in the usual ways for the action of the tan liquor, is to be carefully
examined, and any holes that may be found are to be sewed or otherwise
secured by means which are well known, so as to prevent the liquor from
running through, after which it is in a proper state to be exposed to the
action of the tan liquor in conjunction with mechanical pressure, which I effect
in the following manner:-I provide three frames of similar shapes, made of
wood, copper, or other suitable material, (I may mention that the use
of iron for this purpose, unless covered with a coating of paint, should be
avoided, as its effect would be to blacken the skin or hide,) and furnished at
the sides with ears or loops for the reception of screw bolts, the object being,
by means of the outer frames, to press two skins or hides, one on each side,
against the middle frame, and through an aperture in this middle frame to
introduce the tan liquor, under pressure, into the space thus formed between
the two hides, the effect of which will be to produce a continued filtration or
percolation of the liquor, and in consequence of which the tanning process
rapidly takes place. The middle frame differs from the others in having two
pipes let into it at the top, and a cock let into it at the bottom. One of the
exterior frames being laid flat down with its inner surface uppermost, a skin
or hide previously prepared as aforesaid, is laid or stretched over it, the
middle frame is then laid on, taking care that the edges of the skin or hide
shall be everywhere griped or nipped between the two frames. A second

page_text: skin or hide prepared as aforesaid, is then to be laid on the middle frame;
and, lastly, the other exterior frame is to be laid on, care being taken that
the edges of the second skin or hide shall be everywhere griped or nipped
between the middle frame and the last exterior frame. The frames and
skins or hides are then to be secured by means of screw bolts entering into
screwed holes in the ears or loops. The frames are then to be raised upright;
one of the pipes is to be secured to a pipe communicating with a cistern
containing tan liquor, the other pipe is to be left open for the escape of air,
and the cock at the bottom is to be closed. The cock of the pipe com-
municating with the cistern being opened, the tan liquor contained in the
cistern will flow down, and will occupy the space between the two skins or
hides, driving out the air. When the liquor has risen into the pipe for the
escape of the air, shewing that the space is filled, its cock is to be closed,
upon which the tan liquor between the skins or hides being subjected to
hydrostatic pressure by means of the communication with the cistern, (and
which may be produced, increased, and varied, by methods well known,) will
be forced through the pores or substance of the skins or hides, and will appear
in the form of dew or small drops on their outer surface. The time required
for completing the tanning will vary according to the density of the skins or
bides, the strength of the tan liquor, the amount of the hydrostatic pressure,
and other circumstances. When the skins or hides are found to be tanned,
they are to be removed from the frames, and their outer edges, as far as they
were squeezed or nipped between the frames must be pared off, the hides are
then to be dried and prepared for market in the usual way.
It is not my intention to claim under this Patent the exclusive use of the
frames, screw bolts, pipes, or any other article of apparatus herein-mentioned,
or the use of any particular kind of tan liquor, or any mode or process of
preparing and of finishing skins or hides, save and except the application
of the machines or engines herein described or set forth, or any imitation of
them, for the purpose of causing tan liquor or liquors to pass by filtration or
percolation through skins or hides.
The apparatus herein-described for effecting this purpose is such as I have
employed with success, and consider upon the whole to be the best; but
particular local situations, or other circumstances, may render it expedient to
change the shape of the frames, or their vertical position for some other, or
to enclose between the middle frame and either of the exterior ones, two
or more skins or hides, instead of the single one, as above-mentioned.
The subjoined Drawing is a general representation of the machines or
apparatus already described, in which Figure 1 is a front view; and Figure 2

page_text: is a side view. The same letters of reference indicate the same parts in each
Figure.
A, A, is one of the exterior frames; B, B, is the other exterior frame;
9, are two hides secured between the exterior frames and the middle
frames C, C, by means of the screw bolts a, a, a; f is the cistern containing
the tan liquor; is the pipe through which the tan liquor descends from the
cistern into the space or cavity between the two hides, and which will vary in
length according to the amount of hydrostatic pressure intended to be given;
b is a short pipe, one end of which is fixed in the frame C, and the other in
the pipe e; c is the exit pipe through which the air escapes when the liquor is
running down through the pipe e; d is a cock for the purpose of discharging
the liquid between the skins or hides.
In witness whereof, I, the said Francis Gybbon Spilsbury, have hereunto
set my hand and seal, this Twenty-second day of October, in tlic year
of our Lord One thousand eight hundred and twenty-three.
FRANCIS GYBBON (L.S.) SPILSBURY.
AND BE IT REMEMBERED, that on the Twenty-second day of October,
in the year of our Lord 1823, the aforesaid Francis Gybbon Spilsbury canic
before our said Lord the King in His Chancery, and acknowledged the
Specification aforesaid, and all and every thing therein contained and
specified, in form above written. And also the Specification aforesaid was
stampt according to the tenor of the Statute made for that purpose.
Inrolled the Twenty-second day of October, in the year of our Lord
One thousand eight hundred and twenty-three.