IMPROVEMENTS IN THE MANUFACTURE OF LEATHER AND IN COMPOUNDS AND APPARATUS USED THEREFOR
Year: 1877

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth and Co., Patent
Agency, of Frankfort-on-the-Maine, in the Empire of Germany, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF LEATHER AND IN COMPOUNDS
AND APPARATUS USED THEREFOR." A communication from Friedrich Knapp,
Doctor of Philosophy and Professor, of Brunswick, in the Empire of Germany.
Sealed the 22nd September 1877, and dated the 9th July 1877.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office
of the Commissioners of Patents on the 9th July 1877. -
FRANK WIRTH, of the Firm of Wirth & Co., Patent. Agency, of Frankfort-on-the-
Maine, in the Empire of Germany. "IMPROVEMENTS IN THE MANUFACTURE OF
LEATHER AND IN COMPOUNDS AND APPARATUS USED THEREFOR." [A communication
from Friedrich Knapp, Doctor of Philosophy and Professor, of Brunswick, in the
Empire of Germany.]
This new method of tanning is intended to supersede the method of bark tanning
now in use; the old method of cleaning the hides is however not changed; the.
novelty of the method to which this Invention relates being confined to the two
following chief operations of the tanner, namely, in the dressing and preparation..
The dressing I employ is a mineral tanning material for which, instead of the tan or
other vegetable substances as now used, an oxide salt of iron of peculiar preparation
is used; in the preparation substances of peculiar composition are introduced, never
before used, as well as a new method of manipulating the various processes.
I carry out this Invention as follows, that is to say
First, Dressing. In order to prepare the hides they are placed in a cold solution
of ferric oxide salt, forming the subject of my former application for Letters Patent
dated July 7th, 1877, No. 2624, which has been reduced to a proper consistency, and
the dressing is thus completed in two or at most four days, according to the quantity
of skins or hides treated at once. Relaying the skins, taking out, turning over,.
and other like operations are entirely dispensed with.
a
Secondly, Currying.-After the skins have been tanned with the iron salt solution,

page_text: described in my former application for Letters Patent, dated July 7th, 1877, No.
2624, they are treated with fats and greases in a dissolved form, and with my newly
invented iron soap herein-after described. The greases are dissolved in the manner
now in use, and the leather soaked with them or "stuffed" after the skins have been
sufficiently dried. In this manner the present expensive and tedious hand manipu-
lation, which makes the value of the leather so dependent on the skill and
attention of the workmen, is quite done away with, that is to say, the greasing of
the leather by hand with greases, fat, and like substances, the hanging up in
the drying room, the tramping in the tramping drum, and the working off of the
superabundant greases is thus abolished. Besides the greases now in use,
I use
stearine and paraffine, which are chemically dissolved in the usual manner.
By the use of fats in combination with my newly invented iron solution, forming
the subject of my said former application for Letters Patent, the iron salt and those
substances used for greasing the leather are united in such, a manner on the fibres of
the skin as to form an "iron soap," which is an entirely new product.
I produce the said "iron soap" which I have invented, by precipitating soap from
a solution of soap by means of my newly invented iron salt solution, described in
the said former application for Letters Patent. This iron soap, combined or not with
fatty emulsions, is worked into the leather by means of a drum. This drum consists
of a tramping drum which revolves round a hollow axle, this latter being connected
with a blower by a pipe. The blower drives the air through the hollow axle, and
through pipes to the circumference of the tramping drum, and through the hides.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frank Wirth in the Great Seal Patent Office on the 8th January
.1878.
FRANK WIRTH, of the Firm of Wirth and Co., Patent Agency, of Frankfort-on-
the-Maine, in the Empire of Germany. "IMPROVEMENTS IN THE MANUFACTURE.OF
LEATHER AND IN COMPOUNDS AND APPARATUS USED THEREFOR." A communication
from Friedrich Knapp, Doctor of Philosophy and Professor, of Brunswick, in the
Empire of Germany.
This Invention comprises a novel method of tanning intended to supersede the
method of bark tanning now in use; the old method of cleaning the hides is how-
ever not changed; the novelty of the method to which this Invention relates being
confined to the two following chief operations of the tanner, namely, in the dressing
.and preparation. The dressing I. employ is a mineral tanning material for which,
instead of the tan or other vegetable substances as now used an oxy-salt of iron of
peculiar preparation is used; in the preparation substances of peculiar composition
are introduced, never before used, as well as a new method of manipulating the
various processes.
.:
The said Invention is carried into practice as follows, that is to say
In order to prepare the hides they are placed in a cold solution of ferric oxide
salt, forming the subject of my former Letters Patent, No. 2624, dated July 7,
1877, which has.been reduced to a proper consistency, and the dressing is thus com-
pleted in two or at most four days, according to the quantity of skins or hides treated
at once. Relaying the skins, taking out, turning over, and other like operations are
entirely dispensed with.

page_text: After the skins have been tanned with the iron salt solution, described in the Speci-
fication of my said former Letters Patent, No. 2624, dated July 7, 1877, they
are treated with fats and greases in a dissolved form and with iny new iron soap
herein-after described. The greases are dissolved in the manner now in use, and the
leather soaked with them or
"stuffed "
after the skins have been sufficiently dried.
In this manner the present expensive and tedious hand manipulation, which makes
the value of the leather so dependent on the skill and attention of the workmen,
is quite done away with, that is to say, the greasing of the leather by hand with
greases, fat, and like substances, the hanging up in the drying room, the tramping
in the tramping drum, and the working off of the superabundant greases is thus
abolished. Besides the greases now in use, I use stearine and paraffine, which are
chemically dissolved in the usual manner.
By the use of fats in combination with my newly invented iron solution, forming
the subject of my said former Letters Patent, the iron salt and those substances used
for greasing the leather are united in such a manner on the fibres of the skin as to
form an iron soap, which is an entirely new product.
I produce the said "iron soap" by precipitating soap from a solution of soap by
means of my iron salt solution, described in the Specification of my said former Letters
Patent. This iron soap, combined or not with fatty emulsions, is worked into
the leather by means of the apparatus represented in the accompanying Drawing.
This apparatus consists of a tramping drum W which revolves round its hollow
axle z,, the latter being connected with a blower V by the pipe R. The blower
drives the air through the hollow axle z and pipes m, m¹, to the circumference of the
tramping drum W, and through the hides.
Having thus fully described the said Invention, and the manner of performing
the same, I wish it understood that I claiin,―
First. The tanning and "stuffing" of hides or skins by treating them with a
solution of the compound described in the Specification of my said former Letters
Patent, and with grease or oil dissolved by ordinary solvents.
Second. The use of dissolved stearine and paraffine for the purpose specified.
Third. The apparatus, comprising the drum connected with the blower moving
both simultaneously, as herein set forth and shewn in the Drawing for the purposes
specified.
Fourth. The herein described "iron soap" for use in the treatment of the leather
as and for the purpose specified.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand
and seal, this Fourth day of January, in the year of our Lord One thousand
eight hundred and seventy-eight.
FRANK WIRTH. (L.S.)