IMPROVEMENTS IN APPARATUS FOR GRINDING CORN AND OTHER MATTERS
Year: 1861

page_text: LETTERS PATENT to George Davies, of No. 1, Serle Street, Lincoln's Inn,
in the County of Middlesex, and No. 28, St. Enoch Square, in the City of
Glasgow, Civil Engineer and Patent Agent, for the Invention of
"IMPROVEMENTS IN APPARATUS FOR GRINDING CORN AND OTHER MATTERS."-
A communication from abroad by Charles Placide Nézeraux, of Paris,
Engineer.
Sealed the 31st December 1861, and dated the 3rd July 1861.
PROVISIONAL SPECIFICATION left by the said George Davies at the
Office of the Commissioners of Patents, with his Petition, on the 3rd
July 1861.
I, GEORGE DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County of
Middlesex, and No. 28, St. Enoch Square, in the City of Glasgow, Civil
Engineer and Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR GRINDING CORN AND OTHER
MATTERS," a communication to me from abroad by Charles Placide Nézeraux,
of Paris, Engineer, to be as follows:-
Various attempts have from time to time been made to replace the hori-
zontal system of millstones by the vertical rotation of a circular stone in a
nether stone or bed embracing a part of its circumference, but these attempts
have for the most part failed, because the proper bearing or bedding of the
stones could not be maintained long together on account of the wearing of
the bushes.
The bed also sometimes embraced too great a portion of the circumference,
which increased the said defect; because since the central part wore away
quicker than the extreme ends, the parallelism of the two concentric demi-
circumferences was destroyed.

page_text: The bed stones were also made without transverse grooves, without which
good results could not be obtained; because the object of these grooves is to
receive the crushed grains confined in the holes of the stone, and which are
driven therefrom by the centrifugal force developed by the speed to be again
collected on the edge of the grooves by the "lands" of the revolving stone.
It also occurred that the grain not being distributed in a perfectly uniform
manner over the whole working surface, one of the sides of the stone became
worn more than the other, so that the flour could not be perfectly even and
regular.
It was, moreover, extremely difficult to prevent the heating of the stones,
which produced steam, and unless the vapor was allowed escape as soon as it
was formed,) hindered the proper working of the mill by the clogging or
"greasing" of the stones.
66
The method of setting the stones also to and from each other was com-
plicated and uncertain in its action, which caused frequent derangement.
When the "bedding" of the stones became imperfect (which happened almost
daily), it could only be remedied by the long and difficult process of re-dressing,
which, together with other inconveniences, rendered the system almost
impracticable.
The object of the present Invention is to remedy these defects, and by its
adoption the following advantages are gained:-
Firstly, a saving of about fifty per cent. of the motive power employed.
Secondly, a continuous cooling of the working surfaces, by which all per-
ceptible evaporation is prevented.
Thirdly, perfect uniformity in the flour at whatever speed the stone may be
driven. The flour is also superior to that made in the ordinary mills, because
it has a smaller working space to traverse; and the greater part of the moving
stone working in the open air always takes a certain quantity of air with it,
which cannot but be advantageous to the flour, giving it "body," and rendering
it dry and spongy.
Fourthly, the dressing of the surfaces is obtained in a very simple manner
by merely rocking or oscillating the bed stone on its points of support.
The principal features of the said Invention, by which the foregoing results
are produced, consist,―
Firstly, in employing a nether stone or bed embracing only a fourth part of
the circumference of the moving stone, one of the extremities being about
opposite to the horizontal radius of the circular stone, and the other extremity
being about opposite to the lower vertical radius of the same.
Secondly, in so mounting the bed stone that it can be rocked or oscillated

page_text: on its points of support in order to facilitate the dressing or setting of the
same, and in forming any numbers of inclined transverse grooves therein (three
being preferred).
Thirdly, in the use of pedestals (for carrying the circular or revolving stone)
capable of moving on slides fixed at an angle of about forty-five degrees, so
that as the circular stone is set to or from the bed, it moves on a line passing
through the centre of the curve of the latter.
And, fourthly, in the employment of a small trough or spout (to feed the
grain to the mill), to which an alternate circular or rectilinear motion is
given in order to distribute the grain more evenly between the surfaces of the
stones.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Davies in the Great Seal Patent Office on the
3rd January 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County of Middlesex,
and No. 28, St. Enoch Square, in the City of Glasgow, Civil Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of July, in the year of our Lord One
thousand eight hundred and sixty-one, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said George Davies, Her special licence that I, the said George
Davies, my executors, administrators, and assigns, or such other as I,
the said George Davies, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
nake, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN APPARATUS FOR GRINDING CORN AND OTHER MATTERS,"
being a communication to me from abroad by Charles Placide Nézéraux, of
Paris, Engineer, upon the condition (amongst others) that I, the said George
Davies, my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal

page_text: Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said George Davies, do, hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the fol-
lowing statement in writing, and on reference to the accompanying Drawings,
that is to say-
Various attempts have from time to time been made to replace the hori-
zontal system of millstones by the vertical rotation of a circular stone in a
nether stone or bed embracing a part of its circumference, but these attempts
have for the most part failed, because the proper bearing of the stones
could not be maintained long together on account of the wearing of the
bushes.
The bed also sometimes embraced too great a portion of the circumference,
which increased the said defect; because since the central part wore away
quicker than the extreme ends, the parallelism of the two concentric demi-
circumferences was destroyed.
The bed stones were also made without transverse grooves, without which
good results could not be obtained, because the objects of these grooves is to
receive the crushed grain confined in the holes of the stone, and which are
driven therefrom by the centrifugal force developed by the speed, to be again
collected on the edge of the grooves by the "lands" of the revolving stone.
It also occurred that the grain not being distributed in a perfectly uniform
manner over the whole working surface, one of the sides of the stone became
worn more than the other, so that the flour could not be perfectly even and
regular.
It was, moreover, extremely difficult to prevent the heating of the stones,
which produced and (unless the vapor was allowed to escape as soon as it was
formed) hindered the proper working of the mill by the clogging or "greasing"
of the stones.
The method of setting the stones also to and from each other was com-
plicated and uncertain in its action, which caused frequent derangements.
When the "bedding" of the stones became imperfect (which happened almost
daily), it could only be remedied by the long and difficult process of re-
dressing, which together with other inconveniences rendered the system almost
impracticable.
The object of the present Invention is to remedy these defects, and by its
adoption the following advantages are gained:-
Firstly, a saving of about 50 per cent. of the motive power employed.

page_text: Secondly, a continuous cooling of the working surfaces at the same time
that all perceptible evaporation is prevented.
Thirdly, perfect uniformity in the flour at whatever speed the stone may be
driven. The flour is also superior to that made in the ordinary mills, because
it has a smaller working space to traverse, and the greater part of the moving
stone working in the open air always takes a certain quantity of air with it,
which cannot but be advantageous to the flour, giving it "body," and rendering
it dry and spongy.
Fourthly, the dressing of the surfaces is obtained in a very simple manner
by merely rocking or oscillating the bed stone on its points of support.
The principal features of the said Invention, by which the foregoing results
are produced, consist,-
Firstly, in employing a nether stone or bed embracing only a fourth part of
the circumference of the moving stone, one of the extremities being about
opposite to the horizontal radius of the circular stone, and the other extremity
being about opposite to the lower vertical radius of the same.
Secondly, in so mounting the bed stone that it can be rocked or oscillated
on its points of support in order to facilitate the dressing or setting of the
same, and in forming any number of inclined transverse grooves therein (three
being preferred).
་
Thirdly, in the use of pedestals (for carrying the circular or revolving stone)
capable of moving on slides fixed at an angle of about forty-five degrees, so
that as the circular stone is set to or from the bed, it moves on a line passing
through the centre of the curve of the latter.
And, fourthly, in the employment of a small trough or spout (to feed the
grain to the mill), to which an alternate circular or rectilinear motion is
given in order to distribute the grain more evenly between the surfaces of the
stones.
Such being the nature and object of the said Invention for "Improvements
in Apparatus for Grinding Corn and other Matters," I will now proceed to
describe the manner in which the same is to be or may be performed or
carried into practical effect, and in order that the same may be distinctly
understood, I have annexed hereunto a Sheet of Drawings illustrative thereof,
and have marked the same with figures and letters of reference corresponding.
with those in the following explanation thereof, that is to say :-
Figure 1 in the annexed Drawings represents a side view of a mill con-
structed according to this Invention, wherein the action of the trough or spout
can be seen; Figure 2 is a front view of the mill; Figure 3 is a back view of
the mill; Figure 4 is a view of the driving side of the mill; Figure 5 shows

page_text: the position of the bed stone during the dressing of the same; Figure 6 is a
vertical section taken through the axis of the running stone; Figure 7 is a
vertical section taken through about the centre of the mill at right angles to
the axis of the running stone; Figure 8 shows in detail the running stone,
which in the small mill is made in four parts.
The circular millstone H is fixed in a solid manner on a core I, in which is
adjusted the shaft J, which receives motion from the driving power by means
of the pulley L. This shaft is furnished with bearings M, of tempered cast
steel, so arranged as to bear upon other pieces (also of tempered cast steel)
placed in pillow blocks O, in which are formed. small oil reservoirs. In the
upper and lower parts of these pillow blocks there is a small groove, the object
of which is continually to lubricate the rubbing parts of the shaft. A small
strip of leather or indian-rubber should be interposed between the brasses to
prevent the escape of the oil. The pedestals are of a very simple construc-
tion. It is these which carry the circular stone H, and cause it to advance in
its bed in a perfectly regular manner by moving on slides E, adjusted to an
angle of about forty-five degrees on the frame A, for that purpose; screwed
iron rods R tapped into the pedestals actuate them in a perfectly even manner
by means of a double worn (seen in detail in Figure 7*), gearing into small
wheels of equal size fixed to the extremities of the rods R. This arrangement
allows of an almost insensible augmentation or diminishing of the bearing of
the stones by each turn of the small handle V, which puts the rods R in
motion. A drum A" of plate iron, made of two pieces joined by a hook B",
forms a cover for the stone H; a narrow strip C" (Figure 1) covers the line
of junction. In order to allow of brushing the stone when necessary, there is
a plate-iron door D", which may be opened by the button F".
A sliding
door worked by the pinion H", and corresponding toothed racks, serves to
regulate the necessary admission of air according to the temperature of the
flour. The flour falls by a spout or trough M", whence it is conducted to the
other instruments ordinarily in use. The bed stone A¹ is enclosed in a box B',
of cast iron, with parallel faces, which is carried by four screws H¹, which serve
to advance the stone as it becomes worn. It carries also a ball at its central
part below, which a slight friction suffices to turn or cause to oscillate in any
direction in a hollow spherical box, fixed firmly by means of screws in the outer
box or casing G¹, enclosing the bed stone. This casing G is capable of
turning on pivots or hinges at I, and is supported by the projection J¹ resting on
the transverse bar K', which arrangement allows of the ready lowering of the
bed stone when it requires dressing. For this purpose the small barrel L"
(seen in detail at Figure 6*) is made use of by winding thereon a cord fixed

page_text: at one end to the projection J¹, and at the other end to the barrel. The box
which carries the ball is also so arranged as to bring the stones almost
instantaneously and without any difficulty to a perfect bearing; for which
purpose all that is necessary is to loosen the screws H (which are for the
purpose of fixing the bed stone when adjusted), and to advance the circular
stone by turning the small handle V, which moves the pedestals. The bed
stone is thus brought into coincidence with the circular stone, and it is then
fixed by tightening the screws H'; after which the circular stone is removed
the proper distance required for grinding by turning the handle V in the
opposite direction. The small transverse grooves D' are made in the bed.
stone to receive the grain already crushed and held in the grooves of the.
circular stone, which is driven therein by the centrifugal force developed by
the speed of the revolving stone, to be again drawn out by the "lands" of the.
revolving stone, which grind it completely. These grooves are indispensible to,
the success of the system, without them the grain which is enclosed in the,
grooves of the stone would not be able to disengage itself easily therefrom, and,
would consequently pass out without being perfectly reduced to flour. A
small spout or trough of sheet iron F¹ is fixed in the box B', which encloses.
the bed stone to conduct the grain between the stones. The opening E¹ for
the admission of the grain between the stones should be as small as possible,
so that the stone can seize it quickly, and crush it gradually till it arrives at
the place where the grinding is completed. In order not to let the grain-
escape at the sides it is necessary to form (both at the extremities of the
grooves and at the ends of the opening where the grain enters) small rebates
or projections, which have the same bearing with regard to the revolving stone"
as at the part where the flour is finished. The hopper L¹ is of wood, and a.
small door M is adapted thereto; the use of which is to regulate the quantity
of grain required. In order to do this it is only necessary to lower or to
raise the door from the bottom of the trough by means of a small rack gearing
with two pinions, which are actuated by a small handle. The hopper is firmly;
fixed by four screws passing into iron lugs on the frame A, which are tapped
with holes to correspond. The wooden trough or spout O¹ is covered with
sheet iron at the part where it rubs against the hopper underneath, and has an
alternate circular motion given to it by jointed levers P¹, actuated by the cur-
vilinear groove K. made in a ring of iron, placed on one end of the axle J of
the millstone. The cast-iron cylinders R' turning in opposite directions to.
each other (their distance apart being regulated by the screws tapped into
the pedestals T') act as breakers or squeezers, and are put in motion by spur
wheels U, with long teeth driven from the axle of the mill. Their use is to

page_text: crush the grain as it issues from the trougb, and thus prepare the work for the
millstones. Their application becomes very advantageous when grinding dry
and hard grain, the bran is larger and the flour is finer. The cylinders are
not, however, absolutely necessary, as mills made without them will work well,
but they are advantageous, inasmuch as the produce is sensibly increased. A
small bell X (Figure 1), which gives notice when there is no more grain in
the hopper L', is put in motion by the lever Y, which is terminated by a small
curved party, on which a knob or projection on the principal axle J acts.
Having now described the nature and object of the said Invention for
"Improvements in Apparatus for Grinding Corn and other Matters," together
with the manner in which the same is to be or may be performed or carried
into practical effect, I would here remark that it will be evident that each
organ of the mill is susceptible of a variety of modifications or changes without
departing from the fundamental principles of the Invention as above set forth,
and that the various parts may be made of any suitable materials and dimen-
sions, and that mills formed or constructed according to this Invention are
also adapted for grinding other materials beside grain, such as plaister, bricks,
and other matters requiring to be reduced to powder. In conclusion, I wish
it to be understood that I claim as the Invention communicated to me by the
aforesaid Charles Placide Nézéraux,-
Firstly, so mounting the bed stone of mills with vertical stones that it may
be rocked or lowered on hinges or pivots to facilitate the dressing of the same,
and also forming in the working face of the said stone two or more inclined
grooves, as above described (three being preferred).
Secondly, the arrangement of the moveable pedestals on slides attached to
the framing at an angle of about forty-five degrees, so that the circular stone
is advanced or withdrawn on a line passing through the centre of the arc
formed by the bed stone; and also the giving a slight reciprocating move-
ment, either circular or rectilinear, to the spout which supplies the grain to
the stones.
In witness whereof, I, the said George Davies, have hereunto set my
hand and seal, this Second day of January, in the year of our Lord
One thousand eight hundred and sixty-two.
GEORGE DAVIES. (L.S.)