IMPROVEMENTS IN TANNING
Year: 1867

page_text: LETTERS PATENT to John Gange Franklin, of Broadway, in the County
of Somerset, Tanner, for the Invention of "IMPROVEMENTS IN TANNING."
PROVISIONAL SPECIFICATION left by the said John Gange Franklin
at the Office of the Commissioners of Patents, with his Petition, ou
the 18th January 1867.
I, JOHN GANGE FRANKLIN, of Broadway, in the County of Somerset,
Tanner, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN TANNING," to be as follows:-
My Invention of improvements in tanning has for its object to facilitate
and shorten the process of tanning, and also to improve the quality of the
leather. To this end I use tanning liquor of greater strength than usual,
and the skins are kept constantly in motion in the liquor all the while
the tanning process is going on; this is effected by suspending the skins
in a vertical position on a frame to which motion is communicated by any
suitable gearing. The skins should be arranged in such a manner upon the
frames that they hang down vertically as closely as possible together without
touching, then by causing the frame to rotate horizontally in the tan pit
the skins will be kept in slow but constant motion. The vertical spindle
on which the rotating frame is mounted may be screwed and passed through
a screw box, so that by rotating the shaft the frame may be raised out of
the tan liquor for the purpose of removing the skins therefrom.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Gange Franklin in the Great Seal Patent Office on the
18th July 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
GANGE FRANKLIN, of Broadway, in the County of Somerset, Tanner, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of January, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Gange Franklin, Her special licence that I, the said John
Gange Franklin, my executors, administrators, and assigns, or such others as
I, the said John Gange Franklin, my executors, administrators, and assigns,
should at any 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 " IMPROVE-
MENTS IN TANNING," upon the condition (amongst others) that I, the said
John Gange Franklin, my executors or administrators, 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 John Gange Franklin, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawing hereunto annexed, and to the
letters and figures marked thereon (that is to say) :-
My Invention of "Improvements in Tanning" has for its object to facilitate
and shorten the process of tanning, to produce greater weight in the leather,
and superior quality. These objects are effected by the simple and inexpensive
imachinery herein-after described, whereby a considerable amount of manual
labor usually required in the early stages of the tanning process are dispensed
with.
According to the old process tanning liquors of from twenty-five to forty
degrees of strength are used when skins are sent from the limes to the tan
yard, but by my improved process and machinery tanning liquors of greatly

page_text: increased strength may be employed with advantage; this is effected by
suspending the skins in a vertical position on a frame, to which motion is
communicated by any suitable gearing.
When mechanical power is not attainable a lad of fifteen years of age can
turn one hundred skins on a frame with comparative ease; a suitable arrange-
ment of apparatus is shewn in the accompanying Drawing, which represents
a vertical section of the apparatus. A tan pit of a square form is preferred
for tanning on this principle, as the corners of the pit create a current or
agitation in the liquor as the skins are revolving, which causes a continual
stream of liquor to be passing between the skins.
The skins shewn at a, a, are suspended from a frame or frames b, to which
rotary motion is communicated by means of a driving band C, which passes
round a pulley d on the vertical axle e, from which the frame or frames b aro
suspended. The skins should be arranged in such a manner upon the
frames 6 that they hang down vertically as closely as possible together without
touching. By causing the frame or frames 6 to rotate horizontally in the tan
pit f the skins will be kept in slow but constant motion. The vertical
spindle e on which the rotating frame b is mounted may be screwed and
passed through a screw box g, so that by rotating the shaft e the frame b may
be raised out of the tan liquor for the purpose of removing the skins there-
from. The band c may be driven by any suitable motive engine, but the
arrangement shewn in the Drawing will be found convenient and inexpensive
in construction; it consists simply of a set of pulleys h mounted on a vertical
shaft i, on the upper end of which is keyed a bevil wheel j, which is actuated
by a bevil pinion k on the axle of the winch handle 7.
Having now described my Invention of "Improvements in Tanning," and
having explained the manner of carrying the same into effect, I claim as the
Invention secured to me by Letters Patent as aforesaid, suspending the skins
in a vertical position from a frame, to which motion is communicated so that
the skins may be kept in constant motion in the liquor during the tanning
operation, as herein set forth.
In witness whereof, I, the said John Gange Franklin, have hereunto
set my hand and seal, the Fifteenth day of July, in the year of our
Lord One thousand eight hundred and sixty-seven.
JOHN GANGE FRANKLIN. (L.S.)