IMPROVEMENTS IN TANNING AND ANSION OF ÅRRARATUS FOR THE PURPOSE." PROVISIONAL SPECIFICATION
Year: 1871

page_text: LETTERS PATENT to William Francis, of Number Nineteen, Pinners
Hall, Great Winchester Street, London, Merchant, John Bayley
and Thomas Bayley, the younger, of Lenton, in the County of
Nottingham, for the Invention of "IMPROVEMENTS IN TANNING AND
ANSION OF ÅRRARATUS FOR THE PURPOSE."
PROVISIONAL SPECIFICATION left by the said William Francis,
John Bayley, and Thomas Bayley, the younger, on behalf of
themselves and of Thomas Bayley the elder at the Office of the
Commissioners of Patents, with their Petition, on the 5th May
1871.
We, WILLIAM FRANCIS, of Number Nineteen, Pinners Hall, Great
Winchester Street, London, Merchant, JoHN BAYLEY and THOMAS
BAYLEY, the younger, of Lenton, on behalf of themselves and of
THOMAS BAYLEY, the elder, of the same Place, in the County of
Nottingham, do hereby declare the nature of the said. Invention for

page_text: "IMPROVEMENTS IN TANNING AND IN THE ARRANGEMENT AND CONSTRUCTION OF
Apparatus for THE PURPOSE," to be as follows :—
We connect all our tan pits as well as the preparing pits or taps with
keys or connecting pipes, and we provide a reservoir or supply tank
either on a level with or above the tops of the pits from which the liquor
descends through a pipe hose or other conductor into the first pit, and
thence by a hole in the top of the same, and passes "gradually from pit
to pit until it issues from an outlet in the last of the scrics, whence it
is conducted back into the taps or elsewhere as convenient. We thus
cause a continuous current or stream of tanning liquor to pass through
the pits so as to supply the hides contained therein with a constantly
changing liquor of the same strength, which strength may be increased
at will. By these means the hides will not be in contact with what is
called "stale liquor" but will be exposed to their "shifts" from pit to
pit in a liquor gradually and constantly increasing in strength.
SPECIFICATION filed in pursuance of the conditions of the Letters
Patent, and of an Order of the Lord Chancellor, by the said William
Francis, John Bayley, and Thomas Bayley, the younger, in the
Great Seal Patent Office on the 5th December 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM 2
FRANCIS, of Number Nineteen, Pinners Hall, Great Winchester Street,
London, Merchant, JOHN BAYLEY, and THOMAS BAYLEY, the younger, of
Lenton, on behalf of themselves and of THOMAS BAYLEY, the elder, of
the same Place, in the County of Nottingham, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her 2
Letters Patent, bearing date the Fifth day of May, in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said William Francis, John Bayley; and
Thomas Bayley, the younger, Her special license that we, the said 3
William Francis, John Bayley, and Thomas Bayley, the younger, our
executors, administrators, and assigns, or such others as we, the said
William Francis, John Bayley, and Thomas Bayley, the younger, our
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time, and at all times thereafter during &
.

page_text: 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 "IM-
PROVEMENTS IN TANNING AND IN
THE ARRANGEMENT AND CONSTRUCTION OF
APPARATUS FOR THE PURPOSE," upon the condition (amongst others) that
we, the said William Francis, John Bayley, and Thomas Bayley, the
younger, our executors or administrators, by an instrument in writing
under our, or one of our 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 Scal Patent Office within seven calendar
monthis next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said William Francis, John Bayley, and
Thomas Bayley, the younger, do hereby declare the nature of our said
Invention, and in what manner the same is to be performed, to be par-
ticularly described and ascertained in and by the following statement :——
We employ a number or set of tan pits which we connect or cause to
communicate together in such manner that the tan liquor may pass
from pit to pit, so that it shall pass through all the pits from the first
pit to the last of the series or set of them, a current being formed from
the first pit of the set or series to the last, passing through cach pit. A
reservoir or supply tank is provided, the bottom of which is on a level
with the top of the tan pits, or higher when pressure is required,
to which it supplies tan liquor. The preparing pits, or as they are
technically called taps, also communicate with each other, so that the
liquor may pass from the pit nearest the outlet reservoir to the first of
the series. The liquor after passing through the tan pits passes back
We thus cause a
into the preparing pits, or elsewhere, as convenient.
continuous current or stream of tanning liquor to pass through the pits,
so as to supply the hides contained therein with a constantly changing
liquor of the same strength, which strength may be increased at will.
By these means the hides will not be in contact with what is called
"stale liquor," but will be exposed to their "shifts" from pit to pit in
a liquor gradually and constantly increasing in strength.
In order that the Invention may be fully understood, we proceed to
describe more particularly in what manner the same may be performed.
The taps or preparing pits communicate with each other by means of
keys or connecting pipes, and they also communicate with storing or

page_text: reduced to a strength of about 30 degrees by reason of the tannin
absorbed into or taken up by the hides just removed as tanned; then the
supply tanks B being filled with tanning liquor, at a strength of 40
degrees,. from the store vats A¹ by means of the pump b, the cock dis
opened and liquor flows from the tanks B into the first of the scrics
of pits C entering by the top of the cyc e, and following the course
indicated by the arrows at Figure 2. The density of the liquor in this
pit No. 1 being, as above stated, by reason of the tannin absorbed by
the hides, less than that of the liquor now introduced by its cyc e and
spreading along its bottom, the lighter liquid will be gently pushed
upwards until it passes into the next pit by the orifice, and the supply
being now left open this action will be continuous, and cach successive
pit will, constantly remain filled with a liquor of less density than that
in the pit preceding it, the strength of the liquor diminishing in the
usual regular proportion from the first tan pit to the last, the admission
of liquor to the first pit being regulated according to the calculated
absorption of the hides. Thus, if the liquor is admitted into tan pit
No. 1 at a strength of 40 degrees it may be presumed that the hides
therein will in 24 hours have absorbed about half a degree of tannin,
and the supply of liquor will be so regulated that in this time just so
much fresh liquor will have entered as will surfice to push the whole of
the liquor originally contained in this pit into pit No. 2, the strength
of the liquor in which will be 39 degrees, that in No. 3 will be
39 degrees, and the strength of the liquor thus driven from pit to pit
will decrease progressively in the same ratio to pit No. 60, in which it
will be about 10 degrees. The gradual decrease in the strength of the
liquor in cach pit is here given approximatively, and as it will vary with
the nature of the hides and other circumstances can only be accurately
determined in the actual working thereof. The cock g¹ having been
opened at the same time as that d, and the liquor pushed from pit
No. 60 being permitted to run into reservoir D at the same speed as it
is admitted to the pits by the cock d, a continuous and regular flow
is secured night and day so long as the liquor in reservoir D is not
permitted to rise to the same level as that in the tan pits C, and that
the supply in the tanks B is not exhausted. When the level of the
exhausted liquor in reservoir D is nearly equal to that of the liquor in
the pits C it must be run off either into other reservoirs or into tap No. 8
to profit by whatever tannin may still be retained in it. The supply of
tanks B will be renewed by pumping from the store vats A at any con-

page_text: venient moment. The tanned hides in pit No. 1 are removed every
24 hours, those in pit No. 2 shifted to No. 1, those in No. 3 to No. 2,
and so on successively until those in No. 60 are removed to No. 59, fresh
hides being then introduced into No. 60, so that it takes the hides
60 days to travel through the series of pits shown on the accompanying
Drawings, but the tanning may be expedited by increasing and checked
by lessening the rapidity of the continuous current of liquor. We have
taken the strength of the tanning liquor supplied from tanks B to
bc 40 degrees; in fact the number of pits and strength of tanning
liquor are optional and necessarily dependent upon the description of
hides under treatment, the nature of the bark or tanning, and other
considerations.
"6
"
also
It is very important that the tanning liquor be first led to the bottom
of each pit, for if admitted at once at the top it might pass in a direct
current to the outlet, and could not push the weaker liquor upward, as
it does by reason of its greater density when entering at the bottom
under pressure from the tanks B; and it is in order to further prevent
any issue of the denser befor the-weaker-liquor-that-I-have-placed_the_
inlet and outlet apertures of each pit as far apart as possible. The
eyes" e are very cheap in construction, but we prefer to use partitions,
as illustrated, Figure 3," that is to say, crossing the pit in its entire
breadth, and provided with the shoot or divergent &, which is intended
to cause the liquor to enter the bottom of the pit like a wedge, and
spread in a very broad and thin stream along its bottom. We may
mention that the same may be performed by forming a partition with a
hide or butts suspended across or lengthway of the pit, by which means
they act as conductors of the liquor flowing from the tank or next pit
down to the bottom. If found necessary the eyes may rise above the
level of the top of the pit, so that the orifices may be closed and
the liquor pass from pit to pit through syphons suspended on the top of
the partitions, and a greater pressure at the bottom of each pit be thereby
obtained. In this case it would also be desirable to diminish the size
of the outlet at the bottom of the eye. The current through the pits
might possibly be maintained with regularity by continuously pumping
a liquor direct from the store vats A into the first pits C, but besides
requiring the aid of steam or other constant motive power we believe it
would be difficult to regulate the supply in this manner, and we prefer
pumping firstly into the raised supply tanks B, whereby we obtain our
pressure from a column of liquid, and regulate it simply by means of
•

page_text: the inlet cock and outlet cock g, or by any suitable valves that may
be required.
As previously stated the exhausted liquor received in reservoir D may
be passed into taps No. 8, and from thence back to No. 1 tap, the bark
from which will be thrown into No. 2, when fresh bark is needed in
No. 1 to bring it to the required strength. It will pass from thence to
No. 3, and so on to No. 8 until all the tanning is extracted, when the
spent bark will be carried-away.
The several apparatus employed in this process may be set closer
together or further apart, and excepting as regards the arrangement of
the tan pits C and the superior elevation of the supply tanks B in
different positions in relation to each other than those shewn on the
accompanying Drawings, which are merely intended to illustrate the
working of our improved process, and we lay no claim to any particular
construction of sap, store vat, tank, pit, or connection, as such may bo
greatly varied while retaining our process in its integrity.
We should mention that when the syphons or filters are used we
consider it to be preferable to have the pits constructed in such wisc
that the first pit in which the liquor enters should be the highest, and
the next of them a little lower at the top of the pit, and so on lower
and lower in proportion throughout the set of pits, whereby a greater
pressure is obtained, and the liquor is forced or preforced more rapidly
through the aperture at the bottom of the key or partition. It also
passes through the filter more quickly. The pits thus arranged we
consider best adapted for short shifts.
It should be mentioned by us the liquor is transferred from the
mixing tanks into the raised tank by means of a pump vacuum pipes.
We may mention that the arrows across the pits (commencing from
the raised tank) indicate the course of the stream of liquor; the arrows
commencing at the outlet reservoir indicate where the green hides first
enter and are moved forward against the stream. Every day the outlet
reservoir empties itself into the No. 8 tap at the bottom by a plug hole
or hole on the top; it passes to No. 7, No. 6, No. 5, No. 4, No. 3, No. 2,
No. 1 by a plug hole at the bottom, from thence into No. 2, and mixing
from thence by plug hole at bottom to No. 1 mixing tank; from thence
it is pumped into the raised tank. The mark across each pit shows the
key, the mark near the key indicates the outlet hole on the top of
the nit

page_text: "
The plan before stated represents 60 tan pits, 8 taps, 2 mixing tanks,
and 1 raised tank. The raised tank supplies the pits with a stream of
liquor which passes throughout the scrics, as indicated by the arrows
crossing from corner to corner, the outlet being into the outlet reservoir;
from it the liquor passes into No. 8 tap from the tap on the bottom,
and through a plug hole in bottom only of cach tap from No. 8, 7, 6,
5, 4, 3, 2, 1; thence through a plug hole in bottom, and from thence
into No. 2 mixing tank into No. 1. The raised tank may be filled from
either No. 1 or No. 2 mixing tank either by means of a pump or vacuum
pipe. It must be understood the taps are filled with bark or tanning
material where the tanning liquor is made, and it passes to the mixing
tank which contains no bark.
It is important to indicate that when raised the keys or partitions are
used apertures or openings at the bottom of the keys or partitions may
be lessened in width, by which means the liquor is forced through with
greater impetus, previously indicated, and so passes throughout the
length of the pit or pits at or near the bottom thereof.
We claim as our Invention the process of tanning by means of a
continuous current of tanning liquor supplied, regulated, and directed 2
through the tan pits, substantially as herein-before described.
And I, the said John Bayley, on behalf of myself, William Francis,
and Thomas Bayley, the younger, and Thomas Bayley, the elder,
set my hand and seal, the Third day of November, in the year of
our Lord One thousand eight hundred and seventy-one.
2
Witness,
GEO. JON. ROBINSON,
Patent Office,
Nottingham.
JOHN BAILEY. (L.S.)