IMPROVEMENTS IN DRESSING MILLSTONES FOR CLEANING ALL KINDS OF SMALL GRAIN HAVING A HUSK OR HULL
Year: 1860

page_text: PROVISIONAL SPECIFICATION left by William Henry Orchard at
the Office of the Commissioners of Patents, with his Petition, on the
12th January 1860.-A communication from abroad by Henry Darling,
of New York, in the United States of America.
I, WILLIAM HENRY ORCHARD, of No. 15, Hatton Garden, in the County of
Middlesex, Gentleman, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN DRESSING MILLSTONES FOR CLEANING ALL KINDS OF SMALL
GRAIN HAVING A HUSK OR HULL," a communication to me from abroad by
Henry Darling, of New York, in the United States of America, to be as
follows:-
This Invention has for its object improvements in the form and arrange-
ment of the furrows or grooves of millstones which are employed for hulling
rice or other grain from which it is desired to remove the husk or hull.
For this purpose, in place of forming the grooves or furrows in radial lines
from the centre or eye of the stone to the periphery, and intersecting the same
by straight or curved lines as heretofore practised, I cause the furrows or
grooves which start from or near the centre or eye of the stone to be curved
spirally outwards for about two-thirds of the distance towards the outer
circumference, each groove or furrow then curves in the opposite direction till
it terminates at the periphery. From each of the last-mentioned double-curved
spiral furrows another curved furrow is cut, which starts from each of the said
furrows near the periphery, and runs nearly at right angles to the double-curved
spiral furrow until it terminates at the periphery of the stone near the end of

page_text: the next double-curved spiral furrow, and the said double-curved spiral
furrows are connected by another curved furrow near the eye of the stone.
The foregoing description is applicable to the furrows cut on the face of the
running end of the bed stone, which latter is furnished with a series of
additional curved furrows which start from each of the double-curved spiral
furrows, and connects them with the curved furrows before described, near the
outer circumference of the bed stone.
The double-curved spiral curves before described start from the eye of the
stone with the sharpest end towards the centre, and travel outwards towards
the circumference, and these curves are formed from a curve of increasing
radius, which radius I prefer should commence with about one-twelfth
diameter of stone, and end with about two-thirds diameter; and to prevent
the centrifugal force driving away the grain too rapidly, the curve of the
spiral is reversed, and its direction before arriving at the periphery of the
stone, and the additional curved furrows which connect the double-curved
spiral furrows on the bed stone ensure the grain being rolled over and brought
in contact with every part of the stone before being thrown off at the
periphery.
It will be seen that the form and arrangement of the furrows or grooves of
both the runner and bed stones, previously described, consist entirely of
curves, the delivering grooves of each stone radiating spirally from the centre
or eye of the stone, which arrangement I prefer; but the same is not essential
for the purposes of my Invention, as advantageous results may be obtained
by having the furrows of only one of the stones formed as described, the
furrows of the running stone being composed of curves struck from centres
exterior of the outer circumference of the stone or otherwise.