IMPROVE- MENTS IN THE MANUFACTURE OF WHEAT AND OTHER GRAIN INTO FLOUR, AND IN THE MACHINERY CONNECTED THEREWITH, RT OF WHICH IMPROVEMENTS ARE APPLICABLE TO GRINDING GYPSUM AND SIMILAR SUBSTANCES
Year: 1868

page_text: LETTERS PATENT to Thomas James Baker, of Farndon, near Newark,
in the County of Nottingham, Miller, for the Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF WHEAT AND OTHER GRAIN INTO FLOUR, AND
IN THE MACHINERY CONNECTED THEREWITH, RT OF WHICH IMPROVEMENTS
ARE APPLICABLE TO GRINDING GYPSUM AND SIMILAR SUBSTANCES."
1
Sealed the 20th November 1868, and dated the 25th May 1868.
PROVISIONAL SPECIFICATION left by the said Thomas James Baker
at the Office of the Commissioners of Patents, with his Petition, on
the 25th May 1868.
I, THOMAS JAMES BAKER, of Farndon, near Newark, in the County of
Nottingham, Miller, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MANUFACTURE OF WHEAT AND OTHER GRAIN INTO
FLOUR, AND IN THE MACHINERY CONNECTED THEREWITH, PART OF WHICH IMPROVE-
MENTS ARE APPLICABLE TO GRINDING GYPSUM AND SIMILAR SUBSTANCES," to be as
follows:-
My improvements consist, first, in a new form of feeder by which I am
enabled to regulate the feed in exact proportion to the velocity of the.

page_text: stones. To attain this end I make an adjustable aperture through
which grain or material in granular form is constantly supplied to a
small table furnished with a ledge. The aperture I adjust so as to
permit the grain or other material to heap itself slightly thereupon. I
place this table within range of the action of a finger less or more flexible
fastened upon the spindle of the millstone if driven from above, or upon
a short shaft in continuation of the spindle if driven from below. This
flexible finger at cach revolution of the spindle sweeps from the table
whatever is heaped above the ledge thereof, and as the gravity of the
grain operated upon always supplies through the aperture the portion
which has been removed this action constantly repeated varies or
continues in exact accordance with the velocity of the finger or the
stone spindle to which it is fastened. This finger may be formed of steel,
leather, bristles, or even non-flexible material; it may be single, double,
triple, or multiple; it may be vertical or horizontal, or it may be made
to act at one end of an open or enclosed case and the grain released be
forwarded by a screw. The feature of this part of my Invention on
which I rely is the sweeping of a table constantly supplied with material
by the action of gravity by one or more fingers revolving with or driven
by the stone spindle so as to vary the quantity ground exactly in
proportion to the velocity of the grinding stones.
My second improvement consists in using a double blast to aid in
grinding and cooling the stones and meal jointly. This may be effected
in various ways, first, by a fan placed on the top of the stone which
shall throw air off into the top of the millstone case, as in the Patent
granted to me on the Ninth of August, One thousand eight hundred and
sixty-seven, No. 2291. This fan I raise upon studs above the millstone
so as to allow a space between it and the millstone; into this space I
place two plates, one above the stone and another beneath the fan,
and carry these plates upon arms resting on the millstone case so
that neither revolves. By this means I am enabled to return the
blast at the tips of the fan into the eye of the stone; I close this eye to
the outer air and obtain from the arrangement a blast both in the eye
and round the skirt. A second form of this part of my Invention
consists in placing the fan as above described directly on the top of the
stone closing the eye and placing a blowing fan with an adjusting valve
in the pipe leading therefrom to the eye so as to balance the blast at
the skirt and eye respectively. A third form I employ is closing the

page_text: entire case and leaving the eye and the skirt in connection, placing a
blowing fan thereon to supply air at a pressure, by which it will be
distributed to the eye or the skirt as each requires. The fan on the top
of the stone may be continued in this case also for the purpose of causing
the air injected to whirl round in and so sweep the case. The feature
of this part of my Invention on which I rely is blowing air both into
the eye of the stone and around the skirt at a proportional pressure.
My third improvement consists in placing a flexible tube in the meal
spout, through which I cause the meal to descend, so that when working
with an exhaust I am able to gain a greater strength of exhaust than
heretofore. I apply the exhaust to the meal spout above the flexible
tube and beneath the millstone case so as to draw a large quantity of
air both around the skirt and through the eye of the stones. By means
of this application of the exhaust the meal which is held in the millstone
case when the exhaust is applied as heretofore to the top of the case is
delivered at once into the meal spout, the case is kept dry, the meal and
stones cool, and the stones are not hindered from throwing out the meal
as it is ground, as is the case under the former arrangement.
My fourth improvement consists in a new method of building the
millstone. I form a circular metallic plate with ledges so as to receive
and retain the burrs now held by outside rings and cement. The burrs
are fastened within the ledges by keys and cement or any other known
method. By this means I am enabled to make the surfaces perfectly
true, to turn out the eye, and perfectly to balance the whole. I make
the stone surface much less than heretofore, by leaving a large space
around the eye of the plate which has only arms by which the retaining
rings above described are attached to and carried by the eye and spindle.
To the arms above mentioned I fasten a plate of chilled iron or steel,
the surface of which is kept not quite flush with the surface of the
burrs. The outer edge of this plate does not extend to the inner edge of
the burrs, but leaves a space through which there is a free outflow for
the air over the plate and under the burrs. The surface of this plate
across which the grain passes is formed with corrugations or furrows
similar to those usually cut in the burrs, but my object is not to grind
by them, but only to bruise and prepare the grain for the after grinding
between the burrs themselves. The feature of this part of my Invention
on which I rely is having a framing for the burr stones which can be
made perfectly true as well as perfectly balanced, a metallic surface by

page_text: which I am enabled to bruise the grain in entering between the grinding
surfaces at the eye, together with the facility of supplying the grinding
surfaces with air between the outer edge of the bruising plates and the
inner edge of the burrs.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas James Baker in the Great Seal Patent
Office on the 25th November 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
JAMES BAKER, of Farndon, near Newark, in the County of Nottingham,
Miller, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of May, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-first
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Thomas James Baker, Her special licence that
I, the said Thomas James Baker, my executors, administrators, and
assigns, or such others as I, the said Thomas James Baker, 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 make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF WHEAT AND OTHER GRAIN INTO FLOUR,
AND IN THE MACHINERY CONNECTED THEREWITH, PART OF WHICH IMPROVEMENTS
ARE APPLICABLE TO GRINDING GYPSUM AND SIMILAR SUBSTANCES,"
upon the
condition (amongst others) that I, the said Thomas James Baker, 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
Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas James Baker, do hereby
declare the nature of my said Invention, and in what manner the same

page_text: is to be performed, to be particularly described and ascertained in and by
the following statement :-
My improvements consist, first, in a new form of feeder by which I
am enabled to regulate the feed in exact proportion to the velocity of
the stones. To attain this end I make an adjustable aperture through
which grain or material in granular form is constantly supplied to a
small table furnished with a ledge. The aperture I adjust so as to
permit the grain or other material to heap itself slightly thereupon;
I place this table within range of the action of a finger less or more
flexible fastened upon the spindle of the millstone if driven from above,
or upon a short shaft in continuation of the spindle if driven from
below. This flexible finger at each revolution of the spindle sweeps
from the table whatever is heaped above the ledge thereof, and as the
gravity of the grain operated. upon always supplies through the aperture
the portion which has been removed, this action constantly repeated
varies or continues in exact accordance with the velocity of the finger
or the stone spindle to which it is fastened. This finger may be formed
of steel, leather, bristles, or even non-flexible material, it may be single,
double, triple, or multiple, it may be vertical or horizontal, or it may
be made to act at one end of an open or enclosed case and. the grain
released be forwarded by a screw. The feature of this part of my
Invention on which I rely is. the sweeping of a table constantly supplied
with material by the action of gravity by one or more fingers revolving.
with or driven by the stone spindle so as to vary the quantity ground
exactly in proportion to the velocity of the grinding stones..
My second improvement consists in using a double blast to aid in
grinding and cooling the stones and meal jointly.. This may be
effected in various ways, first, by a fan placed on the top of the stone.
which shall throw air off into the top of the millstone case, as in the
Patent granted to me on the Ninth of August, One thousand eight.
hundred and sixty-seven, Number 2291. This fan I raise upon studa.
above the millstone so as to allow a space between it.and the millstone;.
into this space I place two plates, one above the stone and another
beneath the fan, and carry these plates upon arms resting. on the
millstone case so that neither revolves. By this means I am. enabled.
to return the blast at the tips of the fan into the eye of the stone;.
I close this eye to the outer air, and obtain from the arrangement a
blast both in the eye and round the skirt.. A second form of this.

page_text: part of my Invention consists in placing the fan as above described
directly on the top of the stone, closing the eye, and placing a blowing
fan with an adjusting valve in the pipe leading therefrom to the cyc
so as to balance the blast at the skirt and eye respectively. A third
form I employ is closing the entire case and leaving the eye and the
shirt in connection, placing a blowing fan thereon to supply air at a
pressure, by which it will be distributed to the eye or the skirt as cach
requires. The fan on the top of the stone may be continued in this
case also for the purpose of causing the air injected to whirl round in
and so sweep the case. The feature of this part of my Invention on
which I rely is blowing air both into the eye of the stone and around
the skirt at a proportional pressure.
My third improvement consists in placing a flexible tube in the meal
spout, through which I cause the meal to descend so that when working
with an exhaust I am able to gain a greater strength of exhaust than
heretofore. I apply the exhaust to the meal spout above the flexible
tube, and beneath the millstone case so as to draw a larger quantity of
air both around the skirt and through the eye of the stones. By means
of this application of the exhaust the meal which is held in the
millstone case when the exhaust is applied as heretofore to the top of
the case is delivered at once into the meal spout, the case is kept dry, the
meal and stones cool, and the stones are not hindered from throwing
out the meal as it is ground, as is the case under the former arrangement.
My fourth improvement consists in a new method of building the
millstone. I form a circular metallic plate with ledges so as to receive
and retain the burrs now held by outside rings and cement. The burrs
are fastened within the ledges by keys and cement or any other known
method. By this means I am enabled to make the surfaces perfectly
true, to turn out the eye, and perfectly to balance the whole. I make
the stone surface much less then heretofore by leaving a large space
around the eye of the plate which has only arms by which the retaining
rings above described are attached to and carried by the eye and spindle.
To the arms above mentioned I fasten a plate of chilled iron or steel,
the surface of which is kept not quite flush with the surface of the
burrs. The outer edge of this plate does not extend to the inner edge a
of the burrs, but leaves a space through which there is a free outflow
for the air over the plate and under the burrs. The surface of this
plate across which the grain passes is formed with corrugations or

page_text: furrows similar to those usually cut in the burrs, but my object is not
to grind by them, but only to bruise and prepare the grain for the
after grinding between the burrs themselves. The feature of this part
of my Invention on which I rely is having a framing for the burr
stones which can be made perfectly true as well as perfectly balanced,
a metallic surface by which I am enabled to bruise the grain on
entering between the grinding surfaces at the cyc, together with the
facility of supplying the grinding surfaces with air between the outer
edge of the bruising plates and the inner edge of the burrs.
And in order that my Invention may be more fully understood and
more readily carried into effect I will now proceed to describe the
same, reference being had to the accompanying Drawings on two sheets.
Figure 1 and Figure 1ª represent in plan my first and second
improvements with details; the top of the millstone case shown open
at the eye. Figure 2 and Figure 2 a represent the same improvements
in elevational section with details, the millstone case and grain feeder
being shown closed. Figure 3 represents my third improvement; the
eye of the case and millstone shown separated by the dividing screen or
curtain n*.
On Shect 2 are reprosented various views and details of my improved
metliod of building millstones. Figure 4 represents a plan of a running
millstone as seen from above; Figure 5, a sectional clevation when in
position; Figure 6, a plan as seen when the running millstone is turned
over Figure 7 represents in detail plan, elevation, and elevational
section of the corrugated bruising plate in the running millstone;
Figure 8 represents a plan and elevational section of the bruising plate
in the bedstone; Figure 9 represents a plan and sectional elevation
of the driving or centre bar as adapted to the new millstone. The same
letters or numbers refer to the same or corresponding parts in all the
Figures in which they occur.
With reference to the first part of my said Invention, that is to say,
a new method of feeding millstones with grain or material in granulated
form. a, Figures 2 and 2a, represents a common millstone spindle
broken off below the bedstone; upon the taper square on the top of
this spindle rests the boss a', which is cross cut on its upper surface
(see Figure la) to receive the driving or centre bar S', the hollow cup
in which is shown resting on the balancing ball for which a Patent
was granted to me on the Ninth of August, One thousand eight hundred

page_text: and sixty-seven, No. 2291. In the upper portion of the driving boss a
I drill at right angles to the cross cut for the driving bar two holes so
as to receive two studs & which project from the under side of a plate b
which is fastened upon the end of the spindle b'. By this means the
spindle is carried round at the same rate as the millstone. The
plate is made of such diameter as to throw the grain or granulated
material between the grinding surfaces of the millstones. The spindle 6
revolves in the bearing 5 which is fastened to the table which forms
the bottom of the grain case h, which is divided into two portions, one
containing grain the other open to the eye of the millstone, and it is
fixed to the millstone case by means of the bracket h² by suitable bolts.
The table h¹ has a ledge which permits it to be heaped with grain, the
depth or extent of the heap being determined by the adjustable slide ³
which is regulated by the nut h* and bracket h through the screw rod h
and lever beam h" on the fulcrum . The heap of grain on the ledge h¹
is removed into the millstone eye at each revolution of the spindle 6
by the finger b fastened thereon. The heap is renewed by gravitation
as it is removed, being supplied by the grain pipe d. By this arrange-
ment it is evident that the quantity of grain or granulated material
supplied to the millstones will be proportioned to the revolutions of
the spindle or the millstone spindle a to which it is connected.
When the running millstone is driven from above the finger bis
fastened on the descending spindle. The finger b may be made single
or double or even multiple, may be made flexible or non-flexible, of
steel, iron, brass, leather, bristles, or any such suitable metal or material.
When the millstone spindle is horizontal instead of vertical it is obvious
that the feeding apparatus may be easily adapted thereto. It is obvious
also that the grain instead of being dropped into the millstone eye
inay be dropped into a leading screw by which it may be conveyed to
the millstones.
My second improvement, which is to supply air at a pressure both
to the, eye and the skirt of the stones, will be understood by reference
to the. Figures 1 and 2. I feed the grain as in my first improvement;
placing an air-tight lid upon the inclosed case h.herein-before described
under my first improvement. I make the case C which surrounds. the
millstones, air-tight; also except at the ordinary exit therefrom by the
meal spout. I place a pressure fan m above the millstone case with
which it communicates by means of the pipe m' which is furnished
with a regulating valve m² by which the pressure and quantity of the

page_text: air admitted is adjusted at pleasure. It is obvious that by this method
the running millstone receives and transmits condensed air, while
coolness is maintained in the whole case, the space around the stones
being filled with air which covers them and mingles with the meal.
issuing from them. Different methods may be adopted both for pro-
ducing and distributing the condensed air; two fans may be adopted,
one to the skirt and another to the eye. By this arrangement a greater
difference of pressure may be maintained between the cyc and skirt
than is due to the rotation of the stones. A single fan may be made
to emit two streams which by a regulating valve may be made to
send more air the one way than the other. The fan may be placed
upon the stone, as in a Patent granted to me on the Ninth of August,
One thousand eight hundred and sixty-seven, Number 2291, and by
a dead plate leading back to the eye may be made to act as the fan
shown in the Drawings and described. above. But the double blast
system or system of using condensed air simultaneously at the cye
and the skirt, whether by one fan or two fans or by pumps or other
equivalent, I should regard as coming under this improvement.
My third improvement is a method whereby when working with the
exhaust alone it may be increased in intensity. The meal spout n, see
Figure 3, is shown in section of the usual form, a cloth or other clastic
pipe n is enclosed therein having a funnel-mouth entrance. Between
the millstones and the top of the funnel I insert on one side the pipe or
trunk n leading to the exhaust fan n³. By this arrangement the meal
falls into the elastic pipe n' which regulates its area by the quantity of
meal supplied and the external pressure of the atmosphere, and it is
obvious that with the dividing screen n in action the exhaust may be
increased in intensity until it shall have equalled the weight of the
column of meal in the flexible tube, by the lengthening of which any
pressure desired may be obtained. This inward pressure or exhaust by
the attachment of the flexible pipe n³ underneath the millstone case
gives millers the means of using an increased draught of air through
the stones without the tendency to fill up the case with meal, which
has been the result aforetime when the exhaust has been applied above
the millstone case, thereby hindering the free outflow of meal from.
between the stones.
My fourth improvement, which is a new method of building millstones,
by which I am enabled to bruise the grain before grinding it and to

page_text: Within the ring o
have the surfaces of the stone true as well as balanced I show on
Sheet 2. The metallic plate o having a series of concentric rings or
ledges, shewn in section in Figure 5, is made perfectly true at every part.
In that portion between the two outer rings o³, o, I fasten by the
bolts o, &c. the burrs o usually employed for grinding which are
fastened to each other and bound by a hoop or hoops o' in the usual
way. Within the ring o' I fasten by suitable bolts to the arms of the
bruising plate p, seen in various views in Figure 7.
I fasten the ring 8, Figure 9, in which is cast the driving or centre
bar & on which the stone is carried. It is obvious by the arrangement
that each part will be true and perfectly balanced. The bruising plate p
is so formed that the air which passes down through the arms o can
pass over its outer edge and enter between the stones. In the bed-
stone q' I fasten a bruising plate q by suitable bolts so as to correspond
with the plate p above described. The faces of these bruising plates are
corrugated so as not to grind but bruise by pressure; they are not so
closely adjusted as the burrs are which are employed to pulverise. The
corrugated bruising plates can be set by means of adjusting screws passed
through the bedstone, if this is desired, or by layers of wood or felt or
other suitable material, when adjusted they are fastened in position by
the bolts q³. The bolt heads are inserted, as shewn in the Drawing in
Figures 7 and 8, in radial slots raised above the inner surface of the
plates p and q so that the bruising surfaces are not affected by them.
Having now described my Invention, and the manner in which
the same is to be performed, I declare that I claim as secured to me
thereby,-
Firstly. The method described and shown and any equivalents of the
same by which the grain or granular material is supplied to the mill-
stones according to their varying velocity by means of the finger b, the
heaped plate h, and regulating slide h', together with the combination of
means whereby they are regulated to each other.
Secondly. I claim supplying air at a pressure by one or two fans
simultaneously to the eye and the millstone case, by which condensed air
the common difference of pressure between the eye and the skirt caused
by the rotation of the stone produces a greater quantity ground and
keeps the stones and meal cool.
Thirdly. I claim the sleeve or elastic pipe n inserted in the meal
spout, by which exhaust at a greater pressure than is commonly obtained

page_text: may be used, and also applying the exhaust so obtained below the stone
case so that it will serve to keep the millstone case free from hoop meal,
and aid instead of hindering the action of the stones in grinding and
throwing out the ground material.
Fourthly. I claim the method described and shown in Sheet 2,
whereby millstones may be formed true and balanced.
I also claim the bruising plates, as shown and described, whereby the
grain is prepared for grinding and the air is supplied at a greater distance
from the centre of the stones than formerly to the grinding surfaces.
In witness whereof I have hereunto set my hand and seal, this
Twenty-first day of November, One thousand eight hundred and
sixty-eight.
THOMAS JAMES BAKER. (L.S.)
Witness,
WILLIAM ROBERTSON,
Engineer and Patent Agent,
17, Queen's Chambers,
Market Street,
Manchester.