IMPROVEMENTS IN APPARATUS TO BE USED WHEN TANNING HIDES AND SKINS
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by Henry Draper at the Office of
the Commissioners of Patents, with his Petition, on the 29th
November 1869.
I, HENRY DRAPER, of Bebington, in the County of Cheshire, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
APPARATUS TO BE USED WHEN TANNING HIDES AND SKINS," to be as follows:-.
In tanning hides and skins according to the usual practice the skins
or hides are placed into a pit containing the tan liquor, and each day
they are lifted out therefrom one by one and placed into a heap to drain,
they are then again placed back into the same pit, or into another pit
containing a stronger liquor; this entails a considerable amount of hand
labor.
According to my Invention I arrange the several pits for containing
the tan liquor in a circle, and at the centre of the circle I erect a crane
provided with a long swinging arm or jib, the end of which can be
brought over any one of the pits to lift the hides or skins out of the pit
or lower them down into it; and in order that the crane may simulta

page_text: neously lift out all of the skins contained in a pit I suspend the several
skins in an in an openwork frame. When the skins are to be lifted from
the pit this frame is raised by the crane and is caused to rest above the pit
on ledges or supports provided for the purpose, so that the liquor draining
from the hides or skins runs back into the pit; the hides also being
suspended and separate one from another the draining operation is
effected better than by throwing the skins into a heap. When the skins
have been allowed to drain they may either be lowered by the crane
back again into the same pit, or they can be lowered into another pit
containing a stronger liquor.
The crane may be worked by steam or by hydraulic or other power;
two, three, or more concentric rings of pits may also be constructed
around the crane; some of these pits may be employed for brewing
the tan liquor, the tanning material being placed on openwork gratings
fixed in a frame, which can be lifted in and out of the pits by the
crane.
In some cases I arrange that the frames which support the skins
in the tanning pits shall have a to-and-fro vibratory motion given to
them, so as constantly to bring fresh tan liquor into contact with the
surfaces of the skins.
The
In some cases in order to be enabled readily to raise hides or skins
out of a pit of tan liquor and to allow them to drain before returning
them into the pit, I suspend the hides or skins to the inner cir-
cumference of a large drum capable of being revolved on axes.
drum is only partially immersed in the pit, so that one half of the skins
may be suspended out of the liquor and allowed to drain, whilst the
other half of the hides or skins are immersed in the pit. When the
skins which are out of the pit have been allowed to drain for a sufficient
length of time the drum is turned round so as to lower these skins into
the pit, and raise out of the pit the skins which were before immersed
in it. A to-and-fro rocking motion may be given to the drum, so
that the skins which are in the pit may have fresh liquor constantly
brought into contact with their surfaces.
In some cases in place of digging pits into the ground, as is now
usual, I employ casks or vats, and these vats I provide at their lower
ends with an axis to allow of a slight rocking motion being given to
them, and these allow of the cask or vat being wedged up so as to retain

page_text: it in a fixed position, until it is again desired to give a rocking motion
to it. The skins are suspended in a frame which can be raised and
lowered from the vat; or when a circular cask or vat is employed, as
above described, to form the tan pit a slow revolving motion may be
given to the frame which carries the hides or skins.