Improvements in and relating to Leather Paring Machines.
Year: 1890

page_text: Date of Application, 31st Mar., 1890
Complete Specification Left, 17th Jan., 1891-Accepted, 30th Apr., 1891
PROVISIONAL SPECIFICATION.
Improvements in and relating to Leather Paring Machines.
We, WILHELM HARTMANN and JULIUS THOMSON, of Offenbach on the Main,
in the Empire of Germany, do hereby declare the nature of this invention to be as
follows:-
This invention relates to a leather paring machine which performs, by mechanical
means, the paring which hitherto, in the manufacture of leather, could only be
performed in a satisfactory manner by manual labour. In spite of numerous attempts
having been made in this direction, no one has hitherto succeeded, as far as we are
aware, in producing a machine which, in practice, is capable of replacing hand
labour in paring, so that the latter still constitutes one of the main difficulties in
producing leather. The machines hitherto generally used in paring leather are
leather scraping machines but only effect their object very incompletely, as the
skins, during their operation, easily become hot and dry, but in the manual process,
they are also simultaneously stretched by the use of the shaving knife.
The frame of the machine supports, on its middle cross piece, a table, which is
pivotally mounted in the framework, and, by means of a counterweight, has a
tendency to make an upward movement oscillating upon its pivots. The table
consists of a cast iron frame, provided with a wooden cover. The wood cover is
cut out in the middle, and the orifice thereby resulting is covered with a metal plate,
which again, in its turn, possesses a slit intended for the reception of a pressure
roller described below.
Under the table, also situated on the middle cross piece of the frame of the
machine, a vertical axle is placed, which carries the horizontal knife disc at its
upper end immediately below the table. The disc is provided with curved radial
knives upon its upper surface, and makes a considerable number of revolutions; for
instance, about 3000 revolutions a minute, by means of a belt pulley.
The cutting disc is so arranged that the knives pass directly under the before
mentioned slit in the metal plate of the table at a very little distance from the latter.
A vertical adjustable plunger, which carries at its lower forked end a pressing and
stretching roller, is situated above the middle of the table and in the upper cross
piece of the machine frame. The plunger is provided with a lug or projection on
its upper end, through which an adjusting screw provided with a lock nut passes
and is adapted to engage with the frame of the machine in order to allow of the
downward movement of the plunger being exactly and safely regulated, this move-
ment being performed by means of a foot lever arrangement. By means of a
counterweight, the plunger is retained in its raised position as long as the foot
lever arrangement is not set in action. The distance between the table and the
cutting disc is also regulated by means of an adjustable screw with its corresponding
nut, in that the screw allows of a vertical pushing upwards of the cutting disc. An
adjusting screw, also provided with a lock nut, prevents the table plate from coming
in contact with the knives.
The mode of action of the herein described machine is as follows:-
The hide, which is laid with the fleshy side on the table plate, is stretched at the
required place by means of the above named pressure roller and is pressed down
through the hole in the table when the workman sets in action the treadle lever
arrangement. The knives of the rotating disc then attack the part of the hide thus
stretched and perform the operation of paring in an equally simple and efficient
manner. In consequence of the movable placing of the table and of the counter-
weight acting on the same, the height of the table regulates itself automatically

page_text: according to whether a thick or thin part of the leather coines to be treated. Sur-
rounding the central pressure roller or the plunger and connected to the latter by
means of a sliding sleeve which is preferably spring buffered, there are placed four
smaller stretching or smoothing rollers. These latter are connected with each other
by means of differential bevel wheels and work in such a way that the hind roller
goes slower than the front one whilst the same drive the two side rollers in an
opposite direction. The result is that the hide is always well stretched when
passing between the pressure roller and the knives.
It is self evident that various alterations can be made in the above described
machine without thereby altering the principle of the invention.
The machine can equally well be provided with a vertical or otherwise inclined
table as required.
The arrangement of the knives on the cutting disc can be modified.
The rollers described above can also be so arranged that they are not geared to
one another, they can even be replaced by pressing springs.
Dated this 29th day of March 1890.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in and relating to Leather Paring Machines.
We, WILHELM HARTMANN and JULIUS THOMSON, of Offenbach on the Main,
in the Empire of Germany, do hereby declare the nature of this invention, and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
This invention relates to a leather paring machine which performs, by mechanical
means, the paring which hitherto, in the manufacture of leather, could only be
performed in a satisfactory manner by manual labour. In spite of numerous
attempts having been made in this direction, no one has hitherto succeeded, as far
as we are aware, in producing a machine which, in practice, is capable of replacing
hand labour in paring, so that the latter still constitutes one of the main difficulties
in producing leather. The machines hitherto generally used in paring leather are
leather scraping machines which do the work very indifferently, as the skins, during
their operation, easily become hot and dry, while in the manual process, the skins
are simultaneously stretched by the use of the shaving knife.
On the accompanying drawings a paring machine is shown which does away with
the drawbacks hitherto present in machines of this sort and which allows the paring
of the leather being carried out in a complete manner.
Figure 1 is a side elevation partly in section,
Figure 2 a front elevation partly in section,
Figure 3 a plan, and
Figures 4 to 9 show details of the same.
The frame A of the machine supports, on its middle cross piece, a-table-B-which-
is pivotally mounted-in-the-framework at a and, by means of a counterweight C,
has a tendency to make an upward movement oscillating upon its pivots a.
The
table B consists of a cast iron frame, provided with a cover of wood. The cover is
cut away in the middle, and the orifice thereby resulting is covered with a metal
plate which has a slit intended for the reception of a pressure roller G described
below.
Under the table B on the middle cross piece of the frame A of the machine, a
vertical axle D is placed, which carries the horizontal knife disc E at its upper end
immediately below the table B.
The disc E is provided with curved radial knives

page_text: upon its upper surface in the manner shown in Figures 5 and 6, and makes a con--
siderable number of revolutions; for instance, in the machine represented, the knife.
axle receives about 3000 revolutions a minute, by means of a belt pulley F.
The cutting disc E is so arranged that the knives pass directly under the before
mentioned slit in the metal plate 6 of the table at a very short distance from the
latter. A vertical adjustable plunger H, which carries at its lower forked end a
pressing and stretching roller G, is situated above the middle of the table B and in
the upper cross piece of the machine frame. The plunger H is provided with a
lug or projection on its upper end, through which an adjusting screw ', provided
with a lock nut, passes and is adapted to engage with the frame of the machine in
order to allow of the downward movement of the plunger being exactly and safely
regulated, this movement being performed by means of a foot lever arrangement in
the usual manner. By means of a counterweight I, placed on the lever the-
plunger is retained in its raised position as long as the foot lever arrangement is not
set in action. The distance between the table B and the cutting disc E is also
regulated by means of an adjustable screw d, whilst an adjusting screw c, provided
with a lock nut, prevents the table plate from coming in contact with the knives.
The mode of action of the machine described above is as follows:-
The hide, which is laid with the fleshy side on the table plate, is stretched at the
required place by means of the pressure roller G and is pressed down in the manner
shown in G in Figure 9 through the hole in the table when the workman sets.
in action the treadle lever arrangement. The knives of the rotating disc E then
attack the part of the hide thus stretched and perform the operation of paring in
an equally simple and efficient manner. In consequence of the movable placing of
the table B and of the counterweight acting on the same, the height of the table is
regulated automatically according to whether a thick or thin part of the leather
comes to be treated. Surrounding the central pressure roller G and the plunger H
and connected to the latter by means of a sliding sleeve which is buffered (preferably
by a spring K) there are placed four smaller stretching or smoothing rollers L..
These latter are connected with each other by means of differential bevel wheels (as
shown in Figure 4) in such a way, that the hind roller goes slower than the front
one, whilst the same drive the two side rollers in an opposite direction. The result
is that the hide is always stretched level when passing between the pressure roller
and the knives.
It is evident that various alterations can be made in the above described machines.
without thereby altering the principle of the invention.
The machine can be equally well provided with a vertically or otherwise inclined
table if required. Also the arrangement of the knives on the cutting disc can, in
addition to the manner described, be constructed in the way shown in Figures 7
and 8.
The rollers L can also be arranged not to gear with one another or they can be.
replaced by pressing springs.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
:-
1. A leather paring machine such as described, in which the hide is brought by
means of a pressure roller and plunger through the opening in a movable table
against the rotating knives, in such a way that the table yields correspondingly to
the thin places of the hide and the tension of the leather is maintained as evenly as
possible.
2. In a leather paring machine such as described, the arrangement of several
stretching rollers L placed round the pressure roller G and plunger H and connected
by means of a spring with the plunger, for the purpose of stretching the hide during
the paring.
3. The connection between the stretching rollers L by means of differential

page_text: gearing in such a way that the hind roller revolves slower than the front one and
that the two side rollers revolve in a direction opposed to each other.
Dated this 16th day of January 1891.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham and London, Agents.