Im- PROVEMENTS IN APPARATUS EMPLOYED IN THE MANUFACTURE OF LEATHER
Year: 1860

page_text: PROVISIONAL SPECIFICATION left by Robert Pitt and Stephen Fitchew
Cox at the Office of the Commissioners of Patents, with their Petition,
on the 12th December 1860.
We, ROBERT PITT, of Newark Foundry, in the City of Bath, in the County
of Somerset, Engineer, and STEPHEN FITCHEW Cox, of the City and County
of Bristol, Tanner, do hereby declare the nature of the Invention for "Im-
PROVEMENTS IN APPARATUS EMPLOYED IN THE MANUFACTURE OF LEATHER," to be
as follows:-
This Invention has for its object improvements in apparatus employed in
the manufacture of leather. In the manufacture of leather it is common
to submit the hide or skin to the action of a roller, having screw threads
or worms fixed on its periphery; the roller is pressed firmly against the hide
or skin by a pressing surface, usually another roller, of which the bearings of
the axis are fitted with springs. As the screw roller revolves the screw
thread passes over the whole of that portion of the hide or skin which is
between the rollers, and a slow revolution of the pressing roller carries the
hide or skin forward, so that the whole of the surface is acted on. In such
machines, however, we have found that the hide or skin is liable to be drawn
forward by the screw roller at a greater speed than that at which the pressing
roller or surface is set to travel, the hide or skin slipping on the said surface,
and defective work is thus produced. In some cases, however, the hides or
skins have been fixed to the lower rollers by means of grooves and wedges,

page_text: by which the outer edges of the hides or skins have been absolutely fixed
and incapable of movement, except with the lower rollers; this mode of
holding skins and hides has been found objectionable. To prevent the bides
or skins (when not fixed near their outer edges to the roller) being drawn
forward by the screw roller, we employ another roller which holds the hide
or skin against the pressing roller or surface, and thus retains it securely;
this roller may either be a complete roller extending from side to side of
the machine, or it may be composed of a series of discs or short rollers
mounted at distances apart on the axis. Or in place of this arrangement a
hide or skin may be caused to be held by and to pass between a pair of
feed rollers before passing under the screw roller, the said feed rollers being
so driven that their surface speed may be that at which it is desired that
the hide or skin shall pass forward. It may be observed that the mechanical
instruments used for holding the hides and skins may be varied in form so
long as they are arranged in a suitable manner, to prevent them from being
drawn forward by the screw roller-at-a-greater-speed than that_to_which.
the feed motion of the machine is set, and at the same time allow or cause
the skins or hides to be fed forward at the speed desired without fixing
the outer edges of the skins or hides to the lower roller. In constructing
the spiral or screw-formed thread on the upper roller, we have found that
it is very important that the material used should be very hard, and that
the acting surface should be very close in texture and capable of presenting
a very smooth or polished surface, and we have found by experiment that
such spiral or screw thread may with advantage be made by casting them
of iron on chills, also of wrought iron case or surface hardened, also of hardened
steel, and also of hardened steel fixed or united to iron.