Process and Apparatus for the Rapid Tanning of Hides, applicable also for Dyeing and otherwise Treating Leather.
Year: 1896

page_text: Date of Application (in United Kingdom), 4th Feb., 1896
Complete Specification Left, 3rd Nov., 1896-Accepted, 24th Dec., 1896
PROVISIONAL SPECIFICATION.
Process and Apparatus for the Rapid Tanning of Hides, applicable
also for Dyeing and otherwise Treating Leather.
I, HENRY LÉON JUSTIN ROY of 48, Rue de la Victoire, Paris, France, Banker,
do hereby declare the nature of this invention to be as follows:-
My invention relates to a process of rapid tanning by means of special apparatus
and with or without the employment of electricity.
The use of revolving drums or barrels conjointly with that of strong tanning
liquors and in certain cases with the use of electricity would seem to answer. well
in the case of leathers intended for uses demanding great suppleness and yet such
leathers possess but little merchantable value because the tanning operation being
accompanied by such irregular movements and violent shocks the fibre becomes
broken and a porous spongy, leather is inevitably produced. This is a grave
objection but it is unnoticed in the case of certain kinds of leather while on the
other hand for hides of which it is not desired to develop the grain during the
tanning operation and of which it is important to retain the initial stiffness and
strength of the fibre the use of revolving drums is to be avoided. To satisfactorily
tan hides of this kind it is still necessary to repeatedly handle the hides for the
purpose of removing and replacing them in the pit which is a very laborious and
costly operation that does not admit of assistance by any of the recently recognized
artifices for accelerating the tanning operation.
The tanning machine of my invention consists essentially of means whereby the
hide under treatment is alternately plunged into the tanning liquor and drained
when raised out of the same and while at a considerable inclination or even in the
flat, the whole operation being performed without any irregularity of movement
so as to effect in a more efficient and rapid manner the work done by the tanner in
tanning when he lifts the hides, lays them one upon the other above the adjacent
pit, and then replaces them therein.
In order that the invention may be more definitely understood I have represented.
an example of the machine in the accompanying drawings in which
Figure 1 represents a longitudinal elevation, Figure 2 a transverse section, and.
Figure 3 a plan.
Figure 4 shews a modification of the machine in which only one shaft is used.
The same letters of reference denote like parts in all the figures.
Referring to Figures 1, 2, and 3, the machine consists of a framing B supporting
two parallel shafts A A' one of which receives rotary motion from any source of
power and through any suitable means. These shafts each have a pair of sprocket.

page_text: wheels D D D D₁ fixed upon them and which are connected by an endless
travelling apron T composed of rods or spindles e e connected at the ends by
pitch chain links. It forms in fact two endless pitch chains G G connected by
their joint pins which are parts of the same rods. The sprocket wheels D D D D₁
gear with the two chains G G' so that if motion be imparted to shaft A it will be
transmitted to shaft A' and the apron will be put in motion. The ends of the
rods e carry rollers gg which travel as regards the upper member of the apron
upon guide beams M M and as regards the lower member of the apron upon guide
beams H H which serve as intermediate supports for the apron between the
sprocket wheels. To avoid transverse floxure the rods e e are at the middle
connected to a third endless chain K carrying rollers which as regards the upper
member of the chain travel upon a beam L. The shafts A A' carry pulleys PP
on which the rods e are supported when the rollers of the centre chain K quit the
beam I.
The apparatus above described is placed above the pit F containing the tanning
liquor. To each of the rods ee is suspended a hide to be tanned. When the
charging operation which is effected at point X is completed, if the apparatus is
set in motion in the direction of the arrows the hides are caused to successively
assume the positions a a indicated in Figure 1. Those which are suspended from.
the lower part of the endless apron travel through the liquor in a nearly vertical
position; when they arrive at the end of the machine they are raised and become
beut towards the apron and lapped down in an oblique position towards or upon
the upper member of said apron. At the front end of the machine in order to
prevent their sudden fall the hides are kept lapped towards the apron by rollers RRR
against which the hides bear with an automatic pressure during their downward
movement until on escaping from the lowermost roller they are again wholly
immersed in the liquor and recommences the same series of movements.
Figure 4 represents a modified arrangement of machine having but a single
shaft. In this case the rods of the endless apron may be replaced by wood
strips N mounted between cheeks fixed on a shaft O. During the rotation of the
drum thus formed the hides which are attached to its periphery, successively
assume the positions indicated at a in the figure, the hides being supported at the
front by the rollers to prevent their sudden fall. The machine hereinbefore
described is therefore composed of an endless apron carried upon a pair of drums
or of a single drum put in motion above a pit containing the tanning liquor. The
bides are attached to the exterior surface of the apron or of the drum and in their
motion are caused to plunge into the liquor and are then raised out to be drained,
again immersed, and so on, the object of the machine being as above stated to
produce in an automatic and continuous manner the two movements of immersion
and withdrawal which cause the hide to be impregnated with the liquor, drained
when the tanning liquor has become partially assimilated and then again impregnated
with fresh liquor.
The temperature of the liquor playing a part in the rapidity of the tanning
operation there is generally combined with the machine a special thermo-syphon
indicated in dot-and-dash lines in Figures 1, 2, and 3, and consisting of a vertical
U-shaped tube one of whose limbs receives at its end S from a pipe the liquor
coming from the bottom of the pit while the other limb S¹ returns the liquor to
the surface of the pit by a perforated pipe V. The limb S is heated by an
apparatos consisting essentially of an annular heater enclosing said limb, the
difference of temperature in the two limbs of the U-tube establishing the circulation
of the liquor and the whole being placed in a pit adjacent to the tanning pit.
Electric action may be applied in connection with the tanning machine above
described. To this end upon the beams H H before referred to are applied atrips
of copper à upon which the rollers of the lower member of the endless apron
travel, it being only necessary to connect a source of electricity with these copper
strips and with an anode placed in the pit containing the tanning liquor in order to
form an electric circuit. In this case the elements of the endless apron would be

page_text: made of, or provided with, electrically conductive material and with suitable means
for collecting the current from the copper strips h h. When the machine has only
a single shaft the parts from which the hides are suspended would be conductive
and be externally connected with the source of electricity.
It is considered necessary to lift and replace a hide of average weight one
hundred times before the tannin has entirely permeated it which operation in the
ordinary way occupies from thirty to forty-five days handling two and three times
daily. With the tanning machine whereof the mechanical effect is supplemented
by the employment of suitable tanning liquors (prepared with commercial extracts
well decolourized in admixture according to the colour to be obtained and of a
strength of 0 degrees to 6 degrees Beaumé to which may be added any adjunct
considered useful in ordinary practice) and by heat and in certain cases by
electricity, an ox or cow hide of average weight can be readily tanned in forty-
eight hours, hides in the crust, split hides, and horse hides in twenty-four hours,
and calf skins in six hours. As however it is not indispensable when the machine
is employed, to work day and. night the duration of the tanning operation would
be increased if work be suspended at night.
The two types of machine herein described are each capable when working at a
linear speed of 18 metres per hour and with but a small expenditure of motive
power, of treating 120 hides at one time so that one machine working only by day
would tan upwards of one thousand hides per month.
The right is reserved of constructing the machines of any dimensions suited to
that of the hides to be treated and of such materials as are suitable for the uses
to which they may be applied.
The invention includes not only the machines described but also all other
arrangements working upon the principles herein described and the right to
introduce such modifications in the details as may be judged suitable without
departing from the spirit of the invention is also reserved. I reserve to myself
the right to apply electricity to my tanning machines, of the special thermo-syphon
described, and of any other system of heating applicable thereto. I also reserve
the right to use the said thermo-syphon or other analogous apparatus in connection
with other tanning apparatus. I also reserve the right to apply the tanning
machines herein described or any arrangement on the same principle for dyeing
and otherwise treating or preparing leathers.
Dated this 4th day of February 1896.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
Process and Apparatus for the Rapid Tanning of Hides, applicable
also for Dyeing and otherwise Treating Leather.
I, HENRY LÉON JUSTIN ROY of 48, Rue de la Victoire, Paris, France, Banker,
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 a process of rapid tanning by means of special apparatus
and with or without the employment of electricity.
The use of revolving drums or barrels conjointly with that of strong tanning
liquors and in certain cases with the use of electricity would seem to answer well
in the case of leathers intended for uses demanding great suppleness and yet such
leathers possess. but little merchantable value because the tanning operation being

page_text: accompanied by such irregular movements and violent shocks the fibre becomes
broken and a porous spongy leather is inevitably produced. This is a grave
objection but it is unnoticed in the case of certain kinds of leather while on the
other hand for hides of which it is not desired to develop the grain during the
tanning operation and of which it is important to retain the initial stiffness and
strength of the fibre the use of revolving drums is to be avoided. To satisfactorily
tan hides of this kind it is still necessary to repeatedly handle the hides for the
purpose of removing and replacing them in the pit which is a very laborious and
costly operation that does not admit of assistance by any of the recently recognized
artifices for accelerating the tanning operation.
The tanning machine of my invention consists essentially of means whereby the
hide under treatment is alternately plunged into the tanning liquor and drained
when raised out of the same and while at a considerable inclination or even in the
flat, the whole operation being performed without any irregularity of movement
so as to effect in a more efficient and rapid manner the work done by the tanner
in tanning when be lifts the hides, lays them one upon the other above the adjacent
pit, and then replaces them therein.
In order that the invention may be more definitely understood, I have represented
an example of the machine in the drawings which accompany my Provisional
Specification, in which
Figure 1 represents a longitudinal elevation, Figure 2 a transverse section,
and Figure 3 a plan.
Figure 4 shews a modification of the machine in which only one shaft is used.
The same letters of reference denote like parts in all the figures.
Referring to Figures 1 2 and 3, the machine consists of a framing B supporting
two parallel shafts A A' one of which receives rotary motion from any source of
power and through any suitable means. These shafts each have a pair of sprocket
wheels D D D D' fixed upon them and which are connected by an endless
travelling apron T composed of rods or spindles e e connected at the ends by pitch
chain links. It forms in fact two endless pitch chains G G' connected by their
joint pins which are parts of the same rods. The sprocket wheels D D D D¹
gear with the two chains G G' so that if motion be imparted to shaft A it will be
transmitted to shaft A¹ and the apron will be put in motion. The ends of the
rods ee carry rollers gg which travel as regards the upper member of the apron
upon guide beams M M and as regards the lower member of the apron upon guide
beams H H which serve as intermediate supports for the apron between the
sprocket wheels. To avoid transverse flexure the rods e e are at the middle
connected to a third eudless chain K carrying rollers which as regards the upper
member of the chain travel upon a beam L. The shafts A A¹ carry pulleys P P
on which the rods e are supported when the rollers of the centre chain K quit the
beam L.
The apparatus above described is placed above the pit F containing the tanning
liquor. To each of the rods ee is suspended a hide to be tanned.
When the
charging operation which is effected at point X is completed, if the apparatus is
set in motion in the direction of the arrows the hides are caused to successively
assume the positions a a indicated in Figure 1. Those which are suspended from
the lower part of the endless apron travel through the liquor in a nearly vertical
position and when they arrive at the end of the machine they are raised and
become bent towards the apron and lapped down in an oblique position towards or
upon the upper member of said apron. At the front end of the machine, in order
to prevent their sudden fall, the hides are kept lapped towards the apron by
rollers R R R against which the hides bear with an automatic pressure during
their downward movement until on escaping from the lowermost roller they are
again wholly immersed in the liquor and recommence the same series of
movements.
Figure 4 represents a modified arrangement of machine having but a single
shaft. In this case the rods of the endless apron may be replaced by wood strips N

page_text: mounted between cheeks fixed on a shaft O. During the rotation of the drum
thus formed the hides which are attached to its periphery successively assume
the positions indicated at a in the figure, the hides being supported at the front
by the rollers r r to prevent their sudden fall.
The machine hereinbefore described is therefore composed of an endless apron
carried upon a pair of drums or of a single drum put in motion above a pit
containing the tanning liquor. The hides are attached to the exterior surface of
the apron or of the drum and in their motion are caused to plunge into the liquor
and are then raised out to be drained, again immersed, and so on, the object of the
machine being as above. stated to produce in an automatic and coutinuous manner
the two movements of immersion and withdrawal which cause the hide to be
impregnated with the liquor, drained when the tanning liquor has become partially
assimilated, and then again impregnated with fresh liquor.
The temperature of the liquor playing a part in the rapidity of the tanning
operation there is generally combined with the machine a special thermo-syphon
indicated in dot-and-dash lines in Figures 12 and 3 and consisting of a vertical
U-shaped tube one of whose limbs receives at its end S from a pipe the liquor
coming from the bottom of the pit while the other limb S₁ returns the liquor to
the surface of the pit by a perforated pipe V. The limb S₁ is heated by an
apparatus consisting essentially of an annular heater enclosing said limb, the
difference of temperature in the two limbs of the U-tube establishing the
circulation of the liquor and the whole being placed in a pit adjacent to
the tanning pit.
Electric action may be applied in connection with the tanning machine above
described. To this end upon the beams H H before referred to are applied
strips of copper h h upon which the rollers of the lower member of the endless
apron travel, it being only necessary to connect a source of electricity with these
copper strips and with an anode placed in the pit containing the tanning liquor in
order to form an electric circuit. In this case the elements of the endless apron
would be made of, or provided with, electrically conductive material and with
suitable means for collecting the current from the copper strips h h. When the
machine has only a single shaft the parts from which the hides are suspended
would be conductive and be externally connected with the source of electricity.
It is usually considered necessary to lift and replace a hide of average weight
one hundred times before the tannin has entirely permeated it, which operation in
the ordinary way occupies from thirty to forty-five days handling two and three
times daily. By the employment of the tanning machine herein described, whereof
the mechanical effect is supplemented by the use of suitable tanning liquors
(prepared with commercial extracts well decolourized in admixture according to the'
colour to be obtained and of a strength of 0° to 6° Baumé, to which may be added
any adjunct considered useful in ordinary practice) and by the aid of heat and in
certain cases of electricity, au ox or cow hide of average weight can be readily
tanned in forty-eight hours, hides in the crust, split hides, and horse hides in
twenty-four hours, and calf-skins in six hours. As however it is not indispensable,
when the machine is employed, to work day and night the duration of the tanning
operation would be increased if work be suspended at night.
The two types of machine herein described are each capable, when working at
a linear speed of 18 metres per hour and with but a small expenditure of motive
power, of treating 120 hides at one time so that one machine working only by
day would tan upwards of one thousand hides per month.
The right is reserved of constructing the machines of any dimensions suited to
that of the hides to be treated and of such materials as are suitable for the uses to
which they may be applied.
The invention includes not only the machines described but also all other
arrangements working upon the principles herein described and the right to
introduce such modifications in the details as may be judged suitable without
departing from the spirit of the invention is also reserved. I reserve to myself the

page_text: right to apply electricity to my tanning machines and also the special thermo-
syphon described and any other system of heating applicable thereto. I also
reserve the right to use the said thermo-syphon or other analogous apparatus in
connection with other tanning apparatus. I also reserve the right to apply the
tanning machines herein described, or any arrangement on the same principle, for
dyeing and otherwise treating or preparing leather.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1st. A tanning process for performing mechanically and in a continuous manner
the ordinary hand operations of lifting the hides from the pits, laying them one
upon the other, and then replacing them in the pit, which consists in alternately
plunging the hides into the tanning liquor and draining them when raised out of
the same, the hides being for this purpose suspended over a pit containing the
tanning liquor either from an endless travelling apron or a revolving drum whereby
they are carried through the tanning liquor as hereinbefore described and for the
purpose specified.
2nd. A tanning machine for carrying out the herein-described process, comprising
an endless travelling apron from which the hides are suspended and whereby
they are carried through and raised out of the liquor, in combination with rollers
for guiding the hides on entering the liquor substantially as specified.
3rd. A tanning machine for carrying out the herein-described process, comprising
an endless travelling apron constructed of parallel hide-suspension rods connected
at their extremities by pitch chain links and provided with rollers running upon
guide beams serving as intermediate supports for the apron substantially as
described with reference to Figures 12 and 3.
4th. A tanning machine for use in carrying out the herein-described process,
comprising a drum constructed of cross bars from which the hides are suspended
connected to cheek plates keyed upon a central shaft and placed above the tan
pit in combination with rollers for guiding the hides on entering the tanning liquor
as described with reference to Figure 4.
5th. The employment in connection with the system of tanning machine
described, of the thermo-syphon for heating the tanning liquor as described and
for the purpose specified.
6th. The employment of an electric current in connection with the system of
tanning machine described, in which the apron or drum from which the hides are
suspended is connected with the negative pole and an anode is placed in the
tanning liquor as described.
7th. The application of the herein described machine and process for dyeing or
otherwise treating leather.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agent.