IMPROVEMENTS IN TANNING AND DRESSING LEATHER
Year: 1845

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
Cox and GEORGE Cox, of Gorgie Mills, in the County of Edinburgh, Tanners,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Sixteenth day of January, in the eighth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
John Cox and George Cox, our exors, adñiors, and assigns, Пer especial
licence, full power, sole privilege and authority, that we the said John Cox and
George Cox, our exors, admors, and assigns, or such others as we, the said
John Cox and George Cox, our exors, adors, or assigns, should at any time
agree with, and no others, from time to time and at all times during the term
of years therein expressed, should and lawfully might make, use, excrcise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, our
Invention of "IMPROVEMENTS IN TANNING AND DRESSING LEATHER;" in which said
Letters Patent is contained a proviso, that wo, the said John Cox and George
Cox, shall cause a particular description of the nature of our said Invention,
and in what manner the same is to be performed, to be inrolled in Ier said
Majesty's High Court of Chancery within six calendar months next and
immédiately after the date of the said in part recited Letters Patent, as in and
by the same, reference being thereunto had, will more fully and at large
appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, we, the said
John Cox and George Cox, do hereby declare that the nature of our
improvements in tamming and dressing leather consists in new and improved
methods of applying revolving machines, which shall cause hides and skins or
pieces thereof to be alternately submerged into and emerged from tan liquor,
so that when they shall be above the liquor they shall either lie upon and press
upon each other, or be kept in a continued suspended state, and thereby have
tension of their fibrous substance from the natural operation of their own
gravitation, thus causing their pores somewhat to collapse and become partially
emptied of partially exhausted liquor, and become ready or prepared to absorb
or imbibe a fresh quantity by the renewed operation of the capillary attraction
of the pores when again submerged and kept suspended in the liquor, and thus
relieved from pressure upon each other, or tension of the fibres slackened from
the decrease of weight consequent upon submersion, and also to promote tho
effects from exosmosis and endosmosis by giving motion to the hides when in
a state of suspension in the liquor or motion to the liquor amongt or against
the hides, thereby bringing the hide or skin continually into contact with fresh
or different portions of liquor, which also may cause a degree of percolation
of liquor through the pores. And we declare that the manner in which
the said improvements are to be performed are fully described and ascertained
in and by the following statement thereof, reference being had to the
Drawings hereunto annexed, and to the figures and letters marked thereon
(that is to say)
Various have been the methods attempted or employed to facilitate or
produce the cllects above stated, but all have had disadvantages attending
them, either from expence of apparatus or machinery required, inconveniency
or tediousness of the processes, or pifliculty of producing beneficial results.
Our present object is by simple but effective and beneficial processes to
save manual labour and expence in tanning and dressing hides and skins, or
parts thereof, as well as to hasten the chemical combination of the gelatine of
the hide with the tanning principle, and produce a superior texture of leather
in a moderately short period of time. Our John Cox having already patented
the application of a hollow cylinder or drum (similar to that used by bleachers,
and known as the "dash" or "wash wheel," divided into radial compart
ments, into which hides and skins and tan liquor are to be introduced, the hides
being supported by or upon the radial divisions or arms and the interior
surface of the circumference, and prevented, by confinement in the compart-
ments, from falling out when the machine revolves in a pit containing tan
liquor, which is allowed admission into the compartments by suitable apertures

page_text: in the machine, the weight of hides in each compartment as nearly as possible
counterbalancing the weight in the compartment diametrically opposite, thus
enabling the machine to be moved easily. And our John Cox having also
patented the placing or suspending upon or from a roller or other suitable
figure one or more endless belts of hides or skins over or above another, so as
to hang vertically amongst or out of tan liquor, and so promote the tanning
process and economise space and liquor to a considerable extent.
We would remark that we do not now claim as new or of our Invention the
principle of suspending hides vertically nor of counterbalancing them, various
modes of doing so being already well known. In the present mode, however, of
using the hollow cylinder divided into radial compartments comparatively few
hides can be put in operation at once, and in the present modes of placing belts of
hides over a roller it is impossible to keep them in a straight and even position,
unless by constant attendanco of workmen to pull and draw or lift them in
various directions, so as to correct or rectify the deviations from a straight and
proper position, and prevent the hides from accumulating at one end of the
roller and being wrinkled and damaged, or breaking the machinery by jamming
against the stationary supports, or tumbling or slipping off the roller altogether.
And we would further remark, that even when a single belt of hides passes
over a roller at a time, as by Messrs. Herapath and Cox's patent "roller and
belt process," constant attendance is required to prevent or correct the accidents
and imperfections above stated,
Now it is to lessen, correct, obviate, or remove all these disadvantages
which is the object of our present improvements, and therefore what we claim
as new and of our Invention are, further improved modes of application
of a hollow cylinder divided into radial compartments either as a whole, or
using the radial divisions or arms fewer or more by themselves with or
without the circumference in connection. And also we claim a new mode
of application of a solid cylinder roller, sparred reel, or many-sided figure
or frame made to revolve or vibrate continuously, intermittently, alter-
natingly, regularly or irregularly. And we declare that our new and improved
methods of tanning and dressing leather depend on or consist in tying or
affixing hides and skins singly or severally by means of sufficiently strong
twine or ligatures, or other convenient material or thing, to the circumference
or external curved surface of a cylinder or roller, either solid, hollow, or
sparred, or to the plain surface of radial arms or other figure, as above
stated or further to be described, each hide or skin being tied or allixed at one
end or side, or ends or sides, or part or parts, (but we prefer to attach each
by the butt end) by means of several strings or other fastenings (more or

page_text: less in mumber), the points of connection to the circumference or surface of the
machine of all the strings required to fasten each hide being in the same line
and parallel to the axle or horizon (as shown in Figure 3), which method
of placing the points of connection is necessary for the perfect operation of our
new processes; but still some or considerable deviation from a line parallel to
the axle may be adopted, and still considerable success attend the process, so
that we do not confine ourselves to precise points of aflixing the strings to the
machines we may use.
Care should be taken, however, to keep the hides in as
flat or open position as possible, so that when each is affixed by one end to the
circumference of a cylinder, as above mentioned, and near each other, cach
hide shall either lie in a curved position when upon the upper half of the
circumference, or hang open and even and parallel to each other, or approxi-
mating to these positions, from the under half of the circumference. When a
cylinder has been completely clad or loaded with hides, by having them
attached to it, as above directed, at equal or nearly equal short distances (say,
one inch, more or less,) upon the circumference, and a revolving motion given to
to it at any slow or moderate speed when immersed to the level of the axle, or
nearly so, in tan liquor, the hides or skins shall alternately be submerged, and
hang in or nearly in a perpendicular position and parallel to each other, or
nearly so, from the under half of the circumference amongst the liquor, and
thus be exposed to its action, and afforded the opportunity of having their
pores filled with liquor from the power of capillary attraction and other causes,
and next be elevated or emerged from the liquor and lie and press upon cach
other, overlapping each other, somewhat like thatch or slates upon a roof, but
somewhat in a curvilinear form from the circumference outwards, thereby
causing the pores of the hides or skins to become' partially collapsed by the
natural pressure of their own gravitation, and also causing tension of their
librous texture froin the same cause, thereby squeezing out and parting with a
portion of partially exhausted liquor, and becoming prepared for renewed
absorption of liquor when again submerged as the wheel or cylinder or other
figure revolves or moves.
We may remark that it is not necessary that the cylinder should be hollow
and divided into radial compartments in order to carry our improvements into
operation, but we prefer it to be so constructed that we may combine our
John Cox's former patent mode with our present new mode of tanning, and.
have greater facility in tying or aflixing the strings to the circumference. The.
cuds, or sides, or other parts of the hides or skins may be tied to the circum-
ference of the roller within half an inch (more or less) of each other.

page_text: And we would further remark that we do not confine ourselves to the
greatness of extent of circumference or length of cylinder; but we declare that
the circumference should not be so small as to allow or permit the hides or
skins which may be affixed to it to encircle, or warp, or coil round the.
whole circumference when fully clad with hides, which would thereby prevent
them from falling or slipping properly from the partially coiled position, and
separating frequently or properly from each other and have full exposure to
the liquor. And we further declare that the length of the cylinder or breadth
of the radial divisions or arms should at least be such that the hides or skins
may be somewhat flat upon it; and we find that a cylinder, three to six feet
diameter, and six feet long, is a suitable and convenient size for ordinary butts
or hides, and capable of being clad or loaded with from two hundred to five
hundred hides at once, more or less. And we would still further remark,
that hides or belts of hides may be attached by both ends or extremities to the
circumference of the roller or other surface, and thus be doubled, thereby not
requiring such depth of liquor or size of machine as otherwise might be required.
Further, it is evident that if hides moved in or through liquor is beneficial,
or frequent alternation of submersion and emersion advantageous, so will
giving motion to the liquor, and causing it to circulate among the hides by
pumping or other convenient method be beneficial, and by removing, or with-
drawing liquor from the pits and allowing the hides to remain therein and
drain, and after an interval of time introduce the liquor again, which can be
casily managed by causing two pits to communicate with each other, and by.
the law of equilibrium of fluids the liquor from the full pit will fall in level
and half fill the empty pit, leaving only half of the liquid to be removed by
labour, care being taken to stop the communication between the pits (which
should be near the bottom or made by a syphon) when one pit is to be filled
above half full of liquor, which will happen alternately to each of two pits
thus in reciprocal connection.
That our Inventions may be more fully understood we shall now proceed to
describe the Drawings hereunto annexed, which we consider suflicient to illus-
trate our improvements in tanning and dressing leather; the same letters
being used to indicate the same or similar parts or things in all the Drawings.
DESCRIPTION OF DRAWINGS.
Figure 1 shews a transverse section of revolving cylinder C loaded or clad
with hides A and A'. The hides A are being compressed by their own
gravitation on the upper half of the cylinder, while the hides A' attached to
the under half for the time being hang amongst the liquor in the tan pit P.

page_text: Figure 2 shews a plan of the same; and Figure 3 shews a longitudinal section
of the cylinder C. S, S, S, S, S, shew the attaching points for one hide.
Figure 4 shows a transverse section of spars C', fixed to two or more endless
chains N, N, made of wood, or brass, or other suitable material which will not
injure the leather, and which travel over and under two supporting rollers C, C,
which may have projecting knobs on the circumference to work into corre-
sponding indentations in the chains, and which rollers shall be made to revolve.
To the spars are tied the hides A and A', which are moved or dragged along
when the machine is put in motion, and thus exposes the hides to the same
effects as when Figure 1 is employed. The chains may only go over one
roller and hang perpendicularly into a deep pit, and thus combine part of a
former Patent of our John Cox's.
Figure 5 shews a transverse section of an open radial wheel comprising four
radial rectangular arms C, C, C, C, of sufficient breadth to which to affix the
We prefer
hides, &c., and support them properly when above the liquor.
that the hides be attached to the arms in such manner that when leaving the
liquor they shall hang perpendicularly, as appears at A', and it will be seen,
as the wheel revolves the hiles will be elevated, and rest upon the arm which
succeeds that to which they are tied. In this way the hides will press upon
each other in various directions relative to themselves from transverse to
longitudinal, thereby causing very beneficial effects in tanning. The motion of
this machine may advantageously be intermittent, so that the hides may remain
some time properly suspended and exposed to the liquor. as at A'.
Figure 6 is a plan of the same, shewing the appearance the hides A assume
when thus viewed above the liquor.
Figure 7 is a transverse section of a machine almost of the same construc-
tion as Figure 5, but so modified that it shall be capable of having alternating
motion given to it and accommodate two tan pits by being supported on the
mid wall or division of the pits. It will be noticed that two of the arms C, C+,
are so far removed from the centre of the axle as to permit of their clearing
the mid wall M when the machine is moved. I!ides are to be attached as to
the Figure immediately above mentioned, but it will be seen that only two
arms C, C, have hides attached to them, as shewn at A and A'. The angular
space between the two lots of hides is to be divided into two compartments
C and C, for conveniency to contain sandstones or other convenient and
cheap matters in such quantity as shall counterbalance the hides which may
for the time be raised above the liquor. This additional counterbalancing
weight, as distinct from the hides themselves, is necessary to permit the
machine to be easily moved at all the stages of its motion, especially when

page_text: one lot of hides is more out of the liquor than the other lot, and by altering
the position of some of the sand or stones, say, from C³ into C, the machine
will move, raising the hides A' out of the liquor while the hides A become
immersed. By again shifting the position of the sand or stones into into their
first position the machino will move back again to its first position.
Figure 8 is a transverse section of a machine of the same nature as Figure 7,
but calculated to work only one pit at a time. In this caso the counter-
balancing weight of sand, &c. is to be placed as at C and C³, so as to balanco
in itself when the hides are immersed, but we do not confine ourselves in any
case to any precise position of tho counterbalance, as it may be higher or
lower, or otherwise; neither do we confine ourselves to this mode of moving
our alternating machines, as they and all our machines may readily be moved
by any power communicated by cog wheels, levers, pulleys, &c.
Figure 9 shews a transverse section of a revolving rectangular frame or
frames in or to which hides A and A' are fastened at all ends and sides, so
that by motion being given to the machine the hides shall be alternately in
and out of the liquor, as at A¹ and A, and it will be seen that the weight of
the hides will be supported by different strings during the revolution of the
frames, thereby causing a varying direction of tension of the fibres, which is
Lencficial. Figure 10 is a longitudinal section of the same, shewing the
position of the hides A and A¹.
Now we would have it understood, that we do not confine ourselves to any
size of machines, and some of them may be made to embrace several pits at
once by working upon a common axle or having long radial arms, and may be
moved by wheels or belts or other common machinery in or at any convenient
way or speed, and we declare that they are applicable to the lining, dying,
tawing, loshing, and currying of hides and skins by giving motion and position
The time of immersion or
to the goods in the peculiar ways mentioned.
cmersion of the hides may be left to the judgment of the tanner, but we con-
sider that in general cases alternate immersion and emersion once in an hour
to be sufficiently frequent. We would further remark that all our machines
may be constructed so that the parts to which the hides are to be attached
shall be moveable, or be easily taken from the machine, thus affording facilities
for changing the hides to another pit or machine, or vary their relative position.
The Drawings show spars, marked C', placed in grooves, and which should be
secured in any simple way from falling out when the machine is moved, as one
illustrative mode by which this can be managed, and other methods may easily
be suggested. It is evident also that a machine must either be made to suit

page_text: a pit or a pit to suit it. Also we may add, that if the hides, &c. should be
apt to slip or fall irregularly from the cylinders or travelling surfaces, a friction
roller with a restrained or restricted motion may be introduced as a check or
guide, as at F, in Figures 1 and 4.
Having now fully described the nature of our said Inventions, and the
manner in which they are to be performed, we declare that we do not claim
any part or parts of the machinery above described as being in itself or them-
selves new or newly combined, neither do we claim the fixing or attaching by
ligatures only one belt or continuous sheet of hides by one of its ends to a
roller, nor rolling only one belt of hides at a time upon a roller which may have
been already proposed; but what we claim as new and of our Invention is,―
First, the tanning of hides and skins or parts thereof by connecting a
plurality or series of them, either as single hides, skins, or pieces, or as belts
thereof, to the circumference of a roller or cylinder, so that they shall be kept
continuously in connection with it or attached thereto, and shall not coil com-
pletely around it, but shall separate from each other and hang into tan liquor
from the under half of the circumference or part thereof by the simple opera-
tion of their own gravitation, and approach and close and press upon each
other as they become elevated upon the upper half of the circumference, and
be either still in liquor or removed out of it as the machine revolves, as
described.
Secondly, we claim the affixing hides, &c. to an endless travelling band or
floor of spars which shall be made to be moved and guided by passing over
onc, or two, or more rollers, and to which band or floor the hides shall be
attached, as described, and shewn by Figure 4.
Thirdly, we claim the tanning of hides and skins, or parts thereof, by ticing
or affixing them in manner above described or otherwise to radial arms or
frames of proper dimensions, which shall move upon a centre or pivot, so that
the hides, &c. shall be, by the motion of the machine, alternately made to hang
or be in the liquor and again elevated out of the liquor and made to lie and
press upon each other, and be easily moved by having counterbalancing weight
introduced into the machine, as described.
Fourthly, we claim the tanning of hides and skins, &c. when stretched or
suspended vertically or otherwise in a frame, which we prefer to be rectangular,
and caused to revolve round an axis, as described; but we would have it:
understood that we do not claim stretching or suspending hides in frames,
but merely when in that position causing them to revolve or have motion
curvilinearly or rectilinearly when wholly or partially immersed in tan liquor.

page_text: Fifthly, we claim the tanning of hides and skins, &c. by making the tan
liquor circulate, or move, or vibrate amongst or against them in a pit or pits,
as described.
Sixthly, we claim the tanning of hides, &c. by frequently and alternately
withdrawing tan liquor from or introducing it into pits in which hides &c.,
shall be either suspended or lying, thereby exposing them to alternate and
frequent absorption and expression of liquor, as described. And we would
further have it understood that we do not confine ourselves to the precise
details of either of our Inventions, as similar methods may be employed to
produce the same effects.
In witness whereof, I, the said John Cox, have hereunto set my band
and seal, this Sixteenth day of July, in the year of our Lord One
Enrolled the Sixteenth day of July, in the year of our Lord One thousand
eight hundred and forty-five.