Improvements in Apparatus for Tanning.
Year: 1897

page_text: Date of Application, 28th Aug., 1897-Accepted, 2nd Oct., 1897
COMPLETE SPECIFICATION.
Improvements in Apparatus for Tanning.
I, EDWIN Du Bois of Ralston, County of Lycoming, Pennsylvania, U.S.A.,
Tanner, 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:
This invention relates to apparatus by which sides of leather are suspended in
the tannic acid bath and its object is to bring the tanning agent into contact with
all parts of the leather so that the same shall be evenly tanned. This object is
attained by giving to the sides when submerged in the tanning vat a vertical
reciprocating motion and at the same time to adjacent sides horizontal motions in
opposite directions by means of the mechanism shewn in the accompanying draw-
ing in which Fig. 1 is a perspective view of a tanning vat provided with my
apparatus. Fig. 2 a section on line of Fig. 1 and shewing the relative position
of the sides when suspended in the vat. Figs. 3 and 4 similar sectional views
shewing modifications in the arrangement of the parts.
A is the vat within which and supported upon bearing blocks B, B¹, is a rocking
frame composed side bars C, C, and the cross bars D, D¹.. The side bars are
pivotted upon the bearing blocks at b, 61, and the cross bars are fitted to the side
bars by round tenons d upon which they are adapted to oscillate. Above one end
of the vat, in suitable hangers, is supported a shaft E upon which is an eccentric F.
The eccentric strap G is provided with arms g, g¹, and between arm 9 and cross
bar D is a pitman H shewn forked, the forked ends being rigidly fastened to the
cross bar. To the other arm g¹ is attached a second connecting bar H¹ to hold the
eccentric straps from turning. This connecting bar H¹ may have its free end
pivotted to a fixed support or preferably attached to a rocking frame in a second
tanning vat adjacent to the first, as A' in Fig. 2. From an arm I on the upper
side of bar D, runs a connecting rod J to an arm I' on the under side of the bar D¹.
Upon the upper and lower edges of the bars D, D¹, a series of hooks or pins, pre-
ferably of composition metal to withstand the action of the tannic acid, are driven
in such manner that the hooks of the upper and lower series on each bar alternate
with each other, and the lower hooks of one bar are in line with the upper hooks
on the other.
In operation the sides of leather are suspended by neck and tail from these
hooks, (Fig. 2) being submerged in the tan liquor to such a depth that the rocking
of the frame will not lift any portion of the sides above the level of the liquor. As
the shaft revolves, the arms 9, 91, of the eccentric straps are given a rotary motion.
This causes the frame to rock in the vat and raise and lower the sides. At the same
time the rigid connection of the pitman to the bar D causes the bar to oscillate, an
opposite oscillation being imparted to the bar D¹ through the connecting rod J.
This motion of the cross bars causes the sides to move back and forth at the same
time with their up and down movement, and the manner in which the sides are
suspended causes adjacent sides to move horizontally in opposite directions. It
will seen that by this means corresponding parts of adjacent sides are given

page_text: relative motions in opposite directions. These motions of the sides thoroughly
agitate the tan liquor and cause it to circulate freely between the several sides.
No part of adjacent sides are allowed to adhere to each other, so as to exclude the
liquor from between them.
In Fig. 1 the rocking frame is shewn tilted up to the rear, the eccentric being
in its highest position. In Fig: 2 the frame is in horizontal position, the upper
tions of the cross bars D, D', being, in this position of the frame, thrown
towards each other to the extreme or their respective oscillations, the arrows indi-
cating the direction of motion which the several parts are about to take.
The connecting rod J causes the oscillations of the bars D, D', to be positive and
equal and prevents the sides from being strained or stretched.
In Figs. 3 and 4 cranks are substituted for eccentrics, an obvious substitution,
which y also be made in Figs. 1 and 2. Two shafts E' and Ell are shewn, with
cranks and F from which hang the pitmen H' and H attached to the crois
bars D. By this arrangement the frame C D is supported from the shafts and
is made to rise and fall in the vat in a horizontal position instead of being rocked,
as in Figs. 1 and 2. By revolving the shafts in opposite directions, as indicated by
the arrows in Fig. 3 the cross bars D¹¹ are oscillated and the sides moved relatively
in the same manner as described in connection with Figs. aud 2. By revolving
the shafts in like directions as indicated by the arrows in Fig. 4 the cross bars D¹
are made to oscillate in like directions. In this case the hooks on the upper
portion of one har must be in line with those on the upper portion of the other,
and the hooks on the lower portions of the two bars must also be in line, adjacent
sides being hung from the upper and lower hooks, respectively. The connecting
red J is not required in the arrangement shewn in Figs. 3 and 4 since the cranks
and pitmen give the required positive motions to the cross bars. If the manner
of hanging the sides shewn in Fig. 4 is substituted for that shewn in Fig. 2 the
connecting rod will be attached, as indicated by the broken lines at J¹. Several
vats may be arranged back to back, as indicated in Fig. 2 and the frames in each
operated from one central shaft.
I am aware that prior to my invention a tanning apparatus has been con-
structed in which the sides of leather have been given a vertical motion in the vats,
also in which adjacent sides have been given opposite horizontal motions, and I do
not claim cither of those things broadly.
.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. The combination, with a tanning vat, of a pair of oscillatory bars positioned
us shewn and each provided with a series of hooks or leather supports above and
below its centre of vibration, the upper series of hooks being in different vertical
planes from the lower series on each bar for the purpose set forth, a driving
mechanism, and connections between the driving mechanism and the bars whereby
they are given simultaneous vertical and oscillatory motions,' substantially as
described and shewn.
2. The combination, with a tanning vat, of a frame composed of side
bars and cross bars, the cross bars being journalled in the side bars, a
driving mechanism, a connection between the driving mechanism and
frame whereby the frame is given a vertical motion within the vat and the
cross bars of the frame an oscillatory motion, and hooks or leather supports on the
cross bars so located that adjacent sides of leather suspended therefrom are made
to move in opposite directions by the oscillations of the cross bars, substantially
as described and shewn.
3. The combination, with a tanning vat, of a rocking frame therein composed of
side bars pivotted in the vat and cross bars journalled in the ends of the side bars,
a connecting rod between the cross bars, a driving mechanism, a pitman actuated
by the driving mechanism to rock the frame and oscillate the cross bars, and hooks

page_text: or leather supports on the cross bars so located that adjacent sides of ieather sus-
pended therefrom are made to move in opposite directions by the oscillations of
the cross bars, substantially as described and shewn.
Dated this 28th day of August 1897.
THOMAS R. SHILLITO,
89 Chancery Lane, London, W.C., Agent for the Applicant.