Improvements in Grinding Mills.
Year: 1887

page_text: COMPLETE SPECIFICATION.
Improvements in Grinding Mills.
I, FRANK BEALL, of Decatur, in the County of Macon, and State of Illinois,
United States of America, Millwright, do hereby declare the nature of my invention
for IMPROVEMENTS IN GRINDING MILLS 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 improvements in Grinding Mills and consists in the details
of construction and combination of parts hereinafter set forth and claimed. In the
drawing accompanying and forming a part of this specification, sections of opposing
rolls embodying my invention are shown. The roll a rotates in the direction indicated
by the adjacent arrow at a speed of say 100 revolutions per minute. The roll rotates
in the direction indicated by the arrow next adjacent at a speed of say 250 revolutions
per minute. The roll a has longitudinal furrows formed each of the approximately
tangential surfaces c and the more abrupt surfaces de. Alternate with each furrow c de
is a peripheral surface b. The roll ƒ has furrows formed of approximately tangential
surfaces g and more abrupt surfaces i h, the said furrows being longitudinal with the
roll and of a smaller width than the furrows in roll a. The interposed peripheral
surfaces b shown on roll a may be incorporated in roll if desired. The surfaces d
and h are concave, the surfaces e and i are convex and the abrupt surfaces formed of
the combination of the concave and convex surfaces are, as a natural consequence, of
ogee conformation. The abrupt surfaces of the furrows of the slow roll are presented
in the direction of the rolls rotation and their tendency is to feed the grain toward the
fast roll. The abrupt surfaces of the furrows of the fast roll are presented in the
direction opposed to the rolls rotation.
In operation the grain is subjected in each furrow of the slow roll to the successive
action of a number of the furrows of the fast roll, and such is the relative construction
and arrangement of the various parts that the action on the grain is a combination of
direct pressure and friction. The convex portions of the abrupt surfaces are designed
to avoid cutting the grain, the concave portions of said surfaces are designed to permit
free motion in the grains subjected to the action of the rolls. The peripheral surfaces

page_text: lessen the tendency of the abrupt surfaces to injuriously break the wheat by forming
angles less acute. This will be more readily understood by comparing the furrows of
roll a with the furrows of roll f.
The rolls as shown are designed to be used as a "first break." To adapt them for
use as second and third breaks they must, in addition to their general conformation as
herein before set forth, be provided throughout with longitudinal corrugations.
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. In grinding mills a pair of opposing rolls having differential rotation in opposite
directions and provided with longitudinal furrows composed each of a surface
approximately tangential to the roll and a comparatively abrupt surface outwardly
convex, the abrupt surfaces of the furrows of the slow roll being presented in the
direction of the rolls rotation, the abrupt surfaces of the furrows of the fast roll being
presented in the direction opposed to the rolls rotation, and the said furrows being
either plane or corrugated as desired.
2. In grinding mills, a pair of opposing rolls having differential rotation in opposite
directions and provided with longitudinal furrows composed each of a surface
approximately tangential to the roll and a comparatively abrupt surface of ogee
conformation, the abrupt surfaces of the furrows of the slow roll being presented in
the direction of the rolls rotation, the abrupt surfaces of the furrows of the fast roll
being presented in the direction opposed to the rolls rotation, and the said furrows
being either plane or corrugated as desired.
3. In grinding mills, a roll having longitudinal furrows and intermediate peripheral
surfaces, the furrows and intermediate surfaces being either plane or corrugated, and
the furrows being composed each of an abrupt terminal surface and a comparatively
long surface approximately tangential to the roll.
4. A roll for grinding mills having longitudinal furrows and intermediate peripheral
surfaces, the furrows and intermediate surfaces being either plane or corrugated and the
furrows being composed each of an abrupt ogee surface and a comparatively long
surface approximately tangential to the roll.