IMPROVEMENTS IN FLOUR MILLS
Year: 1880

page_text: LETTERS PATENT to Herbert John Haddan, of the Firm of Herbert and
Company, Solicitors of Patents, of 67, Strand, in the City of Westminster,
Civil Engineer, for an Invention of "IMPROVEMENTS IN FLOUR MILLS."
A communication from abroad by Pierre Tanvez, of Giungamp, in the
Republic of France.
PROVISIONAL SPECIFICATION left by the said Herbert John Haddan at the
Office of the Commissioners of Patents on the 11th May 1880.
"
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. IMPROVE-
MENTS IN FLOUR MILLS." A communication from abroad by Pierre Tanvez, of
Giungamp, in the Republic of France.
The Invention relates to mills for grinding corn or other cereals, and consists
partly in the composition or construction of the grinding tools (mill stones), and
partly in the arrangement of the driving gear and accessories.
The grinding discs (mill stones) are obtained by arranging round a hub or box
alternate sheets of metal and of wood, so as to give them an inclination similar to
that of the grooves of an ordinary mill stone, and by bracing the whole together
with a strong iron ring or rings laid on red hot. Each disc is then brought to the
lathe for planing the surfaces and boring out the hub, after which the grooves are
formed in the wood by a chisel, file, or other tool, so as to lay bare the edges of the
shects on the side where they are intended to cut.
The grooves may run right or left according to the motion of the driving shaft,
and they are made deeper in the centre than towards the circumforence of the
disc.
In order to diminish the wear and tear in the centre of the disc, plates of cast
iron may be made to alternate with steel blades near the hub, while wood is used
near the circumference. The depth of the grooves in the cast iron may be rather
more than half of the thickness of a grain, and beech wood is preferred for
separating the metal blades.
The lower or fixed grinding disc is preferably supported by a triangular plate
resting on a tripod which forms the frame of the mill, said plate supporting

page_text: also the casing which surrounds the stones and carries a hopper for feeding the
stones.
The vertical driving shaft which supports the upper stone is supported by a step
bearing made adjustable in height by a screw spindle and handle, and provided
with a cover which fits over a collar of the shaft so as to prevent the latter from
being lifted.
Between the step bearing and the triangular plate the driving shaft
is provided with a pair of bevel wheels, the upper one of which gears into three
bevel wheels mounted on three horizontal radial shafts which pass through bosses
at the legs of the tripod, and may at their outer extremity be provided with shaft
couplings.
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The bub of the lower grinding stone projects below into the hub of the base-
plate, where it is fixed by set screws. The top of the vertical driving shaft is made
conical, provided with a spreading disc, and surmounted by a screw nut for keeping
the spreading disc and the upper stone in position, To prevent any dust or grains
from getting into the lubricant the hub of the lower grinding disc is hollowed out
at the top, and continued above the grinding surfaces so as to enter a corresponding
recess of the hub of the upper stone. The hollow top end of the lower hub forms
the oil receptacle, from which a wick rises into an upper oil reservoir formed by
the axle box of the upper disc and covered by the spreading disc.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Herbert John Haddan in the Great Seal Patent Office on the 10th
November 1880.
IMPROVE-
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand; in the City of Westminster, Civil Engineer.
MENTS IN FLOUR MILLS." A communication from abroad by Pierre Tauvez, of
Giungamp, in the Republic of France.
The Invention relates to mills for grinding corn or other cereals, and consists
partly in the composition or construction of the grinding tools (mill stones), and
partly in the arrangement of the driving gear and accessories.
The grinding discs (mill stones) are obtained by arranging round a hub or box 3
alternate sheets of metal and of wood, so as to give them an inclination similar to
that of the grooves of an ordinary mill stone, and by bracing the whole together
with a strong iron ring or rings laid on red hot. Each disc is then brought to the
lathe for planing the surfaces and boring out the hub, after which the grooves.are
formed in the wood by a chisel, rasp, or other tool, so as to lay bare the edges of 3
the sheets on the side where they are intended to cut. The grooves may run right
or left according to the motion of the driving shaft, and they are made deeper in
the centre than towards the circumference of the disc. In order to diminish the
wear and tear in the centre of the disc, plates of cast iron may be made to alternate

page_text: with steel blades near the hub, while wood is used near the circuinference. The
depth of the grooves in the cast iron may be rather more than half of the thickness
of a grain, and beech wood is preferred for separating the metal blades. The lower
grinding disc if fixed is preferably supported by a triangular plate resting on a
5 tripod which forms the frame of the mill, said plate supporting also the casing
which surrounds the stones and carries a hopper for feeding the stones.
The vertical driving shaft which supports the revolving stone is supported by a
step bearing, made adjustable in height by a screw spindle and handle. Between
the step bearing and the triangular plate the driving shaft is provided with a pair
0 of bevel wheels, the upper one of which gears into one, two, or three bevel wheels
mounted on horizontal radial shafts which pass through bosses at the legs of the
tripod, and may at their outer extremity be provided with shaft couplings.
Referring to the accompanying Drawings which illustrate the Invention Fig. 1
is a vertical section of a flour mill, while Fig. 2 shows the construction of the
upper grinding disc (upper stone).
Three cast iron feet A, A, A, bolted at the top to a casing A', A¹, and near the
bottom to a main bearing D form the framework which supports the grinding
discs. One of these three feet is provided with two bosses to receive the shaft of
the bevel wheel which imparts motion to the mill. This shaft may be placed in
the upper or lower boss, according to the direction in which the motor revolves.
It is simpler to change the position of the driving shaft than to replace a right cut
stone by a left cut stono when the revolution of the motor is reversed.
The casing shaft A, A, which surrounds the lower stone has at the top three ears Q
for supporting the upper stone by means of three posts O provided with screwed ends.
The cast iron plate holding together the pieces which constitute the upper stone
has three corresponding ears, these ears being intended to hold the stone in an
invariable position.
A ring R of angle iron serves as a cover for retaining the flour or other ground
material.
pro-
The plate which holds together the pieces constituting the lower stone is
vided with rings S, which during their revolution in the groove K take the product
to the discharge opening. Each of the said two plates which hold together the
stones has a nave, the nave of the upper stone being provided with a central
opening for introducing the grain or other material to be subjected to the action of
the stones. Over this plate and around the inlet opening is a bracket for holding
the hopper. The nave of the lower plate is also bored out to give passage to the
shaft F, the end of which is tapered and provided with a screw nut for securing
the lower stone to the shaft. The outer surface of the screw nut is toothed or
serrated and made conical so as to take part in the grinding or cutting action.
Around the naves of the two plates, bored out as described, are cast eight ribs
placed tangential to the circular opening through which the raw material is intro-
duced, and having the thickness of the wedges or packing pieces placed between
the steel blades herein after described. These (approximately radial) ribs reach
to the circumference of the stone, or they may only occupy a part of the
radial width; they mark the place for the other pieces from which the mill stone
is composed, and serve to keep them in their proper place. The millstone B is
supported by the casing A, A¹, while the revolving stone C is keyed on the vertical
shaft F, and secured thereto by a screw nut. (The mill stones which the inventor
used for his trials have only about half a metro of diameter.) The shaft F passes
through the boss of the casing A, A¹, provided with an oil chamber N, and also
through the nave of the fixed stone; it is supported by a step bearing D¹, which
belongs to the bracket D. The step bearing D₁ need not be covered. At the lower
end of the bracket D is a small handweel D for turning a regulating screw to the
right or to the left, according to the distance required between the mill stones.
After the required distance has been once obtained it may be fixed by a set
screw.
The Drawing shows besides tho driving pinion E three similar bevel wheels

page_text: E¹, E, E, the shaft of the latter passing through bosses cast on the feet of the
machine frame. The bevel wheel E¹ may be used for driving similar radial shafts
by which one or more auxiliary machines are set in motion. This mill may thus
form the centre from which several agricultural machines are driven. From the
hopper L the material to be ground passes between the two stones by means of
After the stones have
three openings arranged concentrically around the shaft.
been adjusted and secured in their relative position by the handwheel D¹¹ and the
set screw, the quantity of grain which can be admitted is determined by the
number and shape of the (radial) grooves and the amount of power at disposal.
The further the grooves extend from the centre the greater is the quantity of grain
that can be admitted, and if the power be sufficient the material to be ground will
be broken and reduced to as fine a powder as may be desired.
By this apparatus the finest grain may be ground as well as phosphates, or eveu
stones.
For the latter materials it is necessary to make the intermediate or packing
pieces between the blades of a hard material, and the blades of steel from the central
opening to the circumference of the stone.
The grinding action is effected by the blades, which extend nearly radially from
the centre towards the circumference, the intermediate pieces of wood or of cast
iron which separate the blades from each other serving to hold the grain during the
cutting action of the blades.
The production is limited by the power at disposal, and the quality of the product
depends on the distance of the stones, which can regulated as described.
It is evident that the apparatus described and illustrated by the Drawings may
be varied in many ways without departing from the nature of this Invention, and
that either the upper or the lower stone may be made to revolve.
What I claim is,—
1. The general construction and arrangement of mills, substantially as and for
the purposes described and illustrated.
2. The construction of grinding discs as a substitute for ordinary millstones,
substantially as described.
3. The arrangement of the driving gear, substantially as described and
illustrated.
In witness whereof, I, the said Herbert John Haddan, have hereunto set
my hand and scal, this Tenth day of November, 1880.