Improvements in Machinery or Apparatus for the Treatment of Hides and Skins.
Year: 1889

page_text: Date of Application, 12th Jan., 1889
Complete Specification Left, 17th Aug., 1889-Accepted, 19th Oct., 1889
PROVISIONAL SPECIFICATION.
Improvements in Machinery or Apparatus for the Treatment of
Hides and Skins.
I, HERMANN ERNST FREUDENBERG, of Weinheim, Baden, in the Empire of
Germany, Manufacturer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to the softening, stretching, fleshing and cleansing of hides
and skins, and to apparatus therefor.
Hitherto in tanning by machinery, it has been necessary in consequence of the
skins or hides having been previously either dried or salted, to thoroughly soak them
before commencing to operate upon them. For this purpose the skins were laid
in water to render them soft and pliable so as to prevent them from cracking and
to clean the skins, as far as possible, from blood and dirt.
The next operation is the so called stretching and fleshing of the skins whereby
all particles of flesh and fat on the fleshside as well as all cellular skin with veins
and nerves are removed, thus giving the skin its natural elasticity.
The skins which are to be used for sole-leather are now put into the smoke-house
and those which are to be used for upper leather are treated with milk of lime or by
other suitable means for unhairing the skins, after which the skins are scraped.
After cleansing the, skins again thoroughly so as to remove all the lime or other
ingredients used in the preceding process, the actual tanning process is commenced.
This may be effected in different ways and by different means, the object being to
convert the skins into hides, that is to say, to prepare the tissues in such a way as
will prevent the hides from decaying as well as from absorbing water or from becoming
dried into a hard horny mass and, by compressing the skin, to give them a more
durable elasticity.
After tanning the skins, the dressing process is performed which operation gives
the leather the density necessary for the purpose for which it is intended as well as
the necessary elasticity and smoothness.
This is usually done when the hides are still slightly wet to allow the shaving off
of all uneven and thick portions.
Lastly the hides are washed and stretched and those intended for upper leathers are
treated with oil or fat and then, when they are quite dry, they are finished and
smoothed on the flesh side.
Existing machines are almost entirely confined to the so called dressing of the
tanned hides and all previous operations such as soaking and fleshing could only be
satisfactorily performed by hand.
Trials have been made with certain mechanical arrangements having rotating
knives but these failed to work satisfactorily as they caused cuts and other defects as
long as the knives remained sharp, and performed the fleshing in a very unsatisfactory
way as soon as the knives became rather blunt. The consequence is that practical
tanners have always hitherto adhered to the. old practice of effecting the operation
by hand.
The object of my invention is to prepare the skins by mechanical means but I
entirely dispense with the use of knives for fleshing the skins, and in carrying out
my invention I replace the said knives by a rotating grinding stone against which
the flesh sides of the skins are pressed under a continuous and abundant water jet.
In order to combine the operations of fleshing and stretching the skins, I form the
periphery or face of the grinding stone with grooves diverging from the centre and
intended to answer the purpose of the angular position of a shaving knife as held by
a workman, thus causing a similar stretching action on the skins. I have proved by

page_text: a large number of practical trials that not only are the skins treated in this manner
softened to a much higher degree and all danger of cracking thereby removed but
they are most thoroughly cleaned at the same time from all blood, dirt or putre-
fying matter.
Moreover the actual fleshing operation is effected with my rotating grinding stone
in such a thorough manner without the least damage to the skins as could only be
performed by an exceptionally skilled workman.
Dated the 19th day of January 1889
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Machinery or Apparatus for the Treatment of
Hides and Skins.
1, HERMANN ERNST FREUDENBERG of Weinheim, Baden in the Empire of
Germany, Manufacturer 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:-
My invention relates to an apparatus for the fleshing and softening of untanned
hides and skins.
In tanning it is usually the practice to first soak the dried or salted skins in
water in order to restore their natural pliability and it is common to assist the
softening influence of the water by various mechanical contrivances such as tumblers
or stocks which apparatus are supposed to soften or break the skins by subjecting
them to a violent action.
The next operation is the fleshing of the skins whereby all particles of flesh, fat,
veins and cellular matter are removed from the flesh side of the skin.
This operation of fleshing is most frequently performed in the old way by manual
labor on the tanner's beam with the beam-knife. All mechanical arrangements for
fleshing have met with but little success so far, because they all are based upon the
employment of rotating screw-shaped knives which cause many cuts and other defects
so long as they remain sharp and fail to perform the fleshing at all when, after being
in use for a short time they have become blunt.
The object of my invention is to perform in a single operation the softening and
fleshing which have hitherto required two separate operations and this I do by the
use of a rotating natural grinding stone against which the flesh sides of the skins
are pressed under a continuous jet of water. For the purpose of assisting the action
of the grinding stone I form its periphery or face with deep grooves diverging from
the centre in order to stretch the skins and flatten out all folds or wrinkles.
I have proved by a large number of practical trials that by the action of my
rotating and grooved grinding stone combined with that of the water jet, not only is
the fleshing performed more neatly, and with less damage to stock than by manual
labor, but the skins become softened to a degree hitherto unattainable.
By using my machine it is possible to make leather more pliable and tougher than
by any other method, and at the same time to reduce the cost of labor compared with
hand work to one sixth.
In the accompanying drawing,
Figure 1 is a side elevation and
Figure 2 is a front elevation of a fleshing machine constructed according to my
invention.
The grinding stone A with the shaft C rests on the frame B and is driven by a
pulley B, a loose pulley D¹ heing also provided on the shaft C. As shown in the
drawing the grinding stone has deep grooves R diverging from the middle of its
periphery, which grooves flatten the skin and assist the grinding action of the stone.
A water pipe leading from a tank W is employed whereby a stream of water is

page_text: projected onto the place, where the skin comes into contact with the stone. To the
fixed table E facing the stone is attached the upright J having a moveable elastic
cushion F and connected to the table by the link G.
By means of this upright which is operated by a pedal lever H the required parts
of the skin can be pressed against the stone with the desired degree of pressure.
It will be obvious that other suitable mechanism could be employed for pressing
the skin against the stone, such as a roller, or an endless band.
My machine differs from fluffing wheels, or other shaving machines which are based
upon the employment of a rotating emery wheel, in that all such machinery is used
exclusively for shaving tanned leather in a dry or nearly dry state, and does not act
either on wet or on raw stock. Further my machine cannot be properly worked
without plenty of water, and cannot do the work of the above named shaving machines
on dry leather. The natural stone of my machine will well withstand the action of
water, whereas it is obvious that a wheel lined with emery cloth would not withstand
the action of wet. Moreover the faces of the emery wheels are flat or only very
slightly grooved, and the grooves are wide apart, whilst the grooves on my grinding
stone are made as narrow and as deep as the nature of the stone will admit.
My machine is also new in its application because it has never been attempted to
flesh a raw skin or hide otherwise than by the use of knives, and lastly it is new in its
results because it does the fleshing and softening of raw skins or hides in a manner far
simpler and better than has been done hitherto.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is
The herein described machine for fleshing and softening skins or hides, comprising
a rotary natural grinding stone having deep and narrow angular grooves in its
periphery, against which the skins are pressed by suitable means such as that shown
in the drawing, in combination with an abundant jet of water directed onto the skin
in order to keep the same wet and soft during the fleshing operation.
Dated the 17th day of August 1889.
G. F. REDFERN & Co., .
4, South Street, Finsbury, London, Agents for the Applicant.