Improvements in Tanning Hides and Skins.
Year: 1898

page_text: Date of Application, 27th July, 1898-Accepted, 15th Oct., 1898
COMPLETE SPECIFICATION.
Improvements in Tanning Hides and Skins.
I, JESSE HANDCOCK CURLING, of Trowle Manor, Trowbridge, Wiltshire,
Scientist, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
This invention relates to the tanning of hides and skins and consists in certain
improvements in drum tannage most advantageously applicable to the treatment
of the thicker hides such as cow or ox hides, and which enable me to effectively
tan such hides in but a comparatively short time to that usually occupied, and
to produce leather having the flexibility, firmness and other attributes indispen-
sible to a sound and serviceable product of high quality.
In carrying out the invention, I employ a drum, a, such as that represented
in sectional elevation in Figs. 1, and 2, of the accompanying drawings, and
suspend the hides, b, therein separately and freely without stretching the same.
The drum is made of a relatively large diameter so that the hides can be lifted
well out of the tanning liquor as the drum is slowly revolved, and the hicles are
suspended therein at a distance apart sufficient to keep them well separated while
out of the tanning liquor, and to prevent any undue rubbing thereof together
with the object of ensuring an even tannage colour and the avoidance of grain.
The drum may be made of a width suitable to the suspension of one, two or
more series of hides side by side. The drum is also provided with peripheral
liquid-tight doors, c, through the doorways of which an operative can obtain
access to the drum-interior for suspending and removing the hides. The hides
are separately suspended by the operative punching holes, 61, therein and hanging
the same onto spring hooks, a¹, secured to the drum. The drum is provided
with trunnions, 3, which are mounted on bearings, d, one of the trunnions gear-
ing with a driving shaft e, and the other being made hollow and provided with
an inlet pipe, f, (having a stop-cock, f¹) leading from a main (not represented)
with which connect other pipes having stop-cocks and respectively leading from
reservoirs of the several tanning extracts or liquors which may be required to
be used according to the nature of the hide under treatment, so as to provide
means of supplying to the drum such of such liquors as may be for the time
required therein. The pipe, f, is also provided with an independent inlet and
vent, g, having a stop-cock, g¹, and serving as a means of introducing into the
drum from time to time a quantity of turpentine relatively small in proportion
to the quantity of the tanning liquor employed, as a means of discharging the
contained initial atmosphere of air, and also, from time to time, the gases gene-
rated within the drum, and of substituting therefor an atmosphere of or saturated
with turpentine vapor.
In carrying out the improved process, I employ a relatively small quantity of
the tanning liquor in relation to the capacity of the drum in lieu of a relatively
large quantity as customary in drum tannage, and also freely suspend and re-

page_text: latively widely separate the adjacent hides as aforesaid, and also introduce into
the drum from time to time a quantity of turpentine relatively small in relation
to the quantity of the contained tanning liquor; introducing such material for
the purpose of discharging the initial atmosphere of air contained by the drum
and thereby removing its oxidizing influences which are liable to spot the hides,
and substituting an atmosphere of vapor which is not subject to this disadvan-
tage but has a mellowing influence on the suspended hides, which, alternating
with the tanning action of the tanning liquors, and conjunctively with the use
of the relatively small quantity of tanning liquor is effective in preventing fer-
mentation of the latter and in causing the rapid conversion of the hides into
leather of high quality. I effect the tanning operation firstly by means of weak
tanning liquors of appropriate character conjunctively with a small addition of
turpentine as aforesaid, and gradually raise the strength of the tanning solution
and maintain its strength as desired by the addition from time to time of fresh
extract, and from time to time discharge the gaseous atmosphere of the drum
and admit further additions of turpentine in small quantities and as and for the
purpose aforesaid
The drum is provided with a test-cock, a³, by which part of its liquid contents
may from time to time be drawn off for testing the strength thereof, and with
a liquid outlet, a, by which its contents may be drawn off as required, either for
emptying the drum prior to the removal of the hides, or for substitution by
different liquors or extracts as the nature of the hides may require.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is-
The herein before described improvements in tanning hides and skins, the same
consisting in suspending the hides separately and freely in a drum made of a
relatively large diameter so that the hides can be lifted well out of the tanning
liquor as the drum is slowly revolved and at a distance apart sufficient to keep
them well separated while out of the tanning liquor and to prevent any undue
rubbing thereof together, and in the employment of a relatively small quantity
of tanning liquor in relation to the capacity of the drum, and in the introduc-
tion into the drum from time to time of a quantity of turpentine relatively small
in relation to that of the contained tanning liquor as a means of discharging the
initial atmosphere of air contained in the drum and also from time to time the
gases generated therein and of substituting therefor an atmosphere of or satu-
rated with turpentine vapor, and in submitting the suspended hides while out
of the tanning liquor to the mellowing influence of such vapor alternately with
the tanning action of the liquor while passing therethrough, the hides being
firstly submitted to the action of weak tanning liquors of appropriate character
conjunctively with a relatively small addition of turpentine as aforesaid and the
strength of the tanning liquor being gradually raised until the desired strength
is obtained; whereby fermentation of the tanning liquor is avoided and the rapid
conversion of the hides into leather of high quality is effected, as set forth.
Dated this 21st day of Tule 1000
DAY, DAVIES & HUNT,
Chartered Patent Agents, 321, High Holborn, London, W.C.,
Agents for the Applicant.