Improvements in the Dressing of Mill-stones.
Year: 1890

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by WILEY NICHOLSON HULSEY, Engineer, of Dodd City,
in County of Fannin and State of Texas, United States of America.]
Improvements in the Dressing of Mill-stones.
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane, in the County
of London, Fellow of the Institute of Patent Agents, 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 :-
My invention relates to certain improvements in methods of dressing mill-stones for
grinding corn, wheat and other cereals, and the purpose thereof is to provide a dress
of such form that the grinding shall be accomplished immediately around the eye of
the stone, where the power is exerted at the maximum advantage, and to effect a
perfect finish before discharging, without heating the grain, owing to the fact that by
performing the grinding at, or near, the eye of the stone, where the surface speed is
less and the power greater, than at any other point upon the stone, a large percentage of
friction is avoided and a very material economy of power is effected, while the grain is
thoroughly ground within the shortest distance travelled.
It is my purpose, also, to provide a novel dress whereby the mill may be run at
great speed, and will grind fast and with little heat and give a great yield, and a high
grade of flour or meal.
It is my further purpose to provide a mill stone dress having angular furrows,
intersecting the main furrows of the stone and of gradually increasing depth from their
outward extremities to the points where they intersect the main furrows, said angular
furrows being oppositely inclined upon the upper and lower stones, to form a perfect
cutting system, to discharge the grain over the face of the stone, and throw it toward
the skirt, or edge, thereof, thereby giving a good draft.
It is my purpose, finally, to provide a mill stone dress in which a series of double-
angle furrows are formed about the eye of the stone to do all the heavy work, in
combination with the angular furrows which serve'as secondary grinders and finishers,
as more particularly described hereinafter.
It is my purpose, finally, to provide, a mill stone dress which will give a very high
quality of flour and meal, which will grind a long time without redressing, and which
may be redressed with the expense of a small portion of labour and time.
To enable others skilled in the art to practise my said invention I will proceed
to describe the same in detail, reference being had to the accompanying drawing in
which :-
F
Figure 1 is a plan view of a stone, showing a form of dress embodying my
invention.
Figure 2 is a side view partly in section.
In the said drawings the reference numeral 1 denotes the upper stone, and the.
numeral 2 designates the eye, or draft-circle.
The face of the stone is provided with a series of main furrows 3, substantially
tangential to the eye and extending to the skirt, or periphery of the stone, each being
intersected by a short furrow 4, by which a series of double angle furrows 5 is formed,
closely surrounding the eye 2.
Diverging from each of the main or tangential furrows 3, are one or more angular.
furrows 6, running from the point of intersection to the skirt or periphery of the
stone, and intersecting with the same and with the said main or tangential furrows
are auxiliary or diminishing furrows 7, arranged at an angle with the furrows with
which they intersect.
At the eye of the stone the double angle furrows 5, surround the draft circle closely
and open into angular pockets 8, which receive the grain as it comes from the hopper.

page_text: Each pocket 8. is formed by a main furrow 3, substantially tangential to the eye or
draft circle of the stone, and extending to its skirt, and intersecting at its lower end
with a short furrow 4.
After forming the double angle furrows, which are composed of the intersection of
the inner ends of the main furrows 3, with the short furrows 4, I space off the
remaining part of the face in from two to three parts, according to the size of the stone,
and cut the parallel angular furrows 9, one, two or more of which may intersect the
main furrows. These furrows form a series of angle shoulders which serve to check
the grain and pass it up over the face and from furrow to furrow thus effecting a
perfect finish before discharging.
In applying this dress to the stones (of which I have shown only one in the drawing)
both are formed in the same manner being faced from the skirt of the stone to
the eye.
When the upper and lower stones are placed together, and set the proper distance
apart, the first set of double angle furrows receive and hold the grain by means of the
true face surrounding the eye, where about nine tenths of the work is done, this being
the point where the speed is least and the power most advantageously exerted. Thus
the grain is ground within the shortest possible travel in radial directions and without
heating.
In applying my invention I have about one fifth face on the runner and leave
about one fourth face on the stationary stone. The angular furrows forming less
face to create friction enable the mill to be run at a great speed to grind without
heating and to give an excellent yield of a high grade.
For wheat I prefer to cut the furrow shallow, from about one half to three fourths
of an inch at the eye, while the auxiliary furrows are cut from one fourth to one
half an inch deep, all diminishing and disappearing on the face of the stone. The
face is left true and smooth to finish up, while the furrows are left reasonably
rough to do the grinding and to clean the bran.
For corn, and other grains excepting wheat, all the furrows are cut slightly
deeper and left rough and I may throw a few straw furrows 9 upon the face, as
shewn in the drawing, although I do not regard this as essential.
By my invention the emptying of the grain from one angle pocket to another gives
a temporary rest and allows a slight interval for cooling, while at the same time it
gives the stone opportunity to thoroughly finish it before it is discharged. In effect
the process is double acting, and double discharging.
By my invention the grinding is confined to the furrows and not merely to a
temporary dress which has to be frequently renewed. My dress will run for a term of
years doing all the work in the angle furrows the face being left smooth for finish.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. In a mill stone dress, a series of double angle furrows, surrounding the eye and
opening into angular pockets which closely surround said eye, one of the furrows
being substantially tangential to said eye and extending to the skirt of the stone, in
combination with one or more angular furrows parallel with each other and lying at
an angle with the main furrows, and diminishing or auxiliary furrows formed at an
angle to both, but parallel with each other and lying between the parallel angular
furrows, and extending to or toward the skirt of the stone at an angle with the radial
line, substantially as described.
2. In a mill stone dress, the combination with a series of main furrows, substantially
tangential to the eye, of a series of short furrows opening into pockets 8, surrounding
the eye, substantially as described.
3. In a mill stone dress, the combination with a series of main furrows, substantially
tangential to the eye, of a series of short furrows opening into pockets 8, a series of
angular furrows intersecting the main furrows, and a series of diminishing or auxiliary

page_text: furrows at an angle with and intersecting both the main and the angular furrows,
substantially as described.
4. In a mill stone dress, the combination with a series of double angle furrows
opening into pockets 8, surrounding the eye, of a series of angular furrows running
from the main furrows to the skirt of the stone and diminishing or auxiliary furrows
formed at an angle with and intersecting both the main and the angular furrows, and
passing into the face, substantially as described.
OUL
T1900
ABEL & IMRAY,
Agents for the Applicant.