Improvements in and relating to Roller Mills.
Year: 1898

page_text: Date of Application, 6th Jan., 1898-Accepted, 12th Feb., 1898
COMPLETE SPECIFICATION.
Improvements in and relating to Roller Mills.
We, ROSIA WASHINGTON WELCH, Master Miller, and ISIDORE LOUIS MYERS,
Cattle Broker, residing respectively at 1416, Robert Street, and 103, North Liberty
Street, in the City of Baltimore, and State of Maryland, United States of America,
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:
:-
The result aimed at in this class of mills is to thoroughly grind and reduce the
grain without destroying its granular character, and to avoid the rubbing or
attrition of the material between opposing surfaces which would result in the
crushing of the grain into impalpable powder.
The present invention is designed as an improvement on that class of roller
grinding mills heretofore used, in which one roller of a pair is provided with longi-
tudinal grooves, running parallel to the axis of the roller, and with circumferential
grooves intersecting the longitudinal grooves at right angles, while the companion
roller is provided with longitudinal grooves only. While rollers thus formed
partially accomplish the result aimed at, we have found that they produce only a
percentage of middlings (from which the highest grade flour is made), the
remainder of the product being what is technically termed break" flour which is
incapable of being purified into the high grade of best flour.
"6
By repeated experiments we have discovered that the defect in the rollers here-
tofore used and above referred to, is due to the fact that the roller which is grooved
only longitudinally, does not permit the grain to slip or drop away quickly enough
from the roller. We have also found by practical experiments and tests, that a
vastly superior result is accomplished, by forming both rollers of the pair with both
longitudinal and transverse circumferential grooves intersecting at substantially
right angles.
We have also discovered that the yield of middlings is greatly increased by
forming the longitudinal grooves in the rollers at a slight angle to the axis of the
roller, or slightly spiral with relation to the axis of the rollers.
Our present invention therefore consists in the features as thus briefly. outlined
and as clearly defined in the appended claims.
In the accompanying drawings,
Figure 1 is a plan view of a pair of rollers embodying our invention.
Figures 2, 3 and 4, are respectively an enlarged plan view, a longitudinal sectional
elevation, and a transverse section of a portion of one of the rollers, and
Figure 5 is an enlarged end elevation of the rollers, partly broken away.
The reference numeral 1, indicates the casing, and 2 the bearings for supporting
the roller shafts 3 and 4.
5 and 6 indicate the co-acting rollers, each of which is provided with a series
of parallel transverse circumferential grooves 7, arranged equi-distant from one
another.
Each of the rollers 5 and 6 is also formed with a series of substantially parallel

page_text: longitudinally peripheral grooves 8, which intersect the grooves 7 to form
pyramidal projections 9.
The grooves 8 are preferably formed at a slight inclination to the axes of the
rollers, the inclination of the grooves 8 in one roller being preferably in a direction
opposite to that of the grooves 8 in the other rollers.
It will be apparent that the construction thus described presents a largely
increased number of inclined surfaces for the escape of the ground material and
also correspondingly increases the number of co-acting crushing surfaces, whereby
the kernels are torn into small particles or comminuted without any rubbing action.
It will be understood that one of the rollers is driven at a higher surface speed
than the other, thus avoiding the contact of the material with opposing parallel
surfaces.
Our experiments have demonstrated that the improved construction of rollers
above described, produces an appreciably greater percentage of strictly pure
granular flour than any other corrugated rollers heretofore employed, and that too
without cutting the germ or bran.
A further important advantage of the present improvement is found in the fact
that friction is materially reduced, thus lessening the heat, and effecting a great
saving in driving power.
I
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is:-
1. In a roller mill, a pair of co-acting rollers, each of which is formed with a
series of transverse circumferential grooves, and a series of longitudinal peripheral
grooves intersecting the transverse grooves.
2. In a roller mill, a pair of co-acting rollers, each of which is formed with a
series of transverse circumferential grooves, and a series of longitudinal peripheral
grooves arranged at a slight angle to the axis of the roller, and intersecting trans-
verse grooves.
3. In a roller mill, a pair of co-acting rollers, each of which is formed with a
series of transverse circumferential grooves and a series of longitudinal peripheral
grooves arranged at an angle to the axis of the roller, 'the inclination of the longi-
tudinal grooves in one roller being in a direction opposite to that of the longitudinal
grooves in the other roller.
4. In a roller mill, a pair of co-acting rollers, both of which are grooved trans-
versely and longitudinally to form series of opposing pyramidal projections on their
peripheries.
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