IMPROVEMENTS IN THE TREATMENT AND GRINDING OF
Year: 1854

page_text: LETTERS PATENT to John Currie, of Glasgow, in the County of Lanark,
North Britain, Miller, and Robert Young, of the same Place. Engineer.
for the Invention of "IMPROVEMENTS IN THE TREATMENT AND GRINDING OF
"
North Britain, Miller, and Robert Young, of the same Place, Engineer.
for the Invention of "IMPROVEMENTS IN THE TREATMENT AND GRINDING OF
"
for the Invention of "IMPROVEMENTS IN THE TREATMENT AND GRINDING OP
PRODUCTS TWO
PROVISIONAL SPECIFICATION left by the said John Currie and Robert
Young at the Office of the Commissioners of Patents, with their Petition,
on the 9th June 1854.
We, JOHN CURRIE, of Glasgow, in the County of Lanark, North Britain,
Miller, and ROBERT YOUNG, of the same Place, Engineer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN THE TREATMENT AND
GRINDING OF GRAIN AND THE PRODUCTS THEREOF" to be as follows:-
These improvements relate, primarily, to the washing and cleansing of
Egyptian wheat and other grain, by passing it from a screen or riddle into one
end of a long narrow water trough, having a perforated false bottom of semi-
circular section. Above this is a horizontal longitudinal shaft, with a series of
inclined blades or paddle arms upon it, such arms being fitted to work just
clear of the false bottom, and at a considerable depth beneath the water surface.
The paddles are adjustable at any angle with their axis of revolution, and as
they revolve. they agitate the grain in the water, and convey it to the opposite

page_text: or delivery end of the trough, whence it is lifted out by a dipping chain of
perforated buckets, by which chain also the paddle shaft is driven. The clean
washing water enters the trough at the end where the grain is taken out, and
a constant current flows off at the end where the grain enters, carrying with it
the floating refuse, whilst the heavier foreign matter escapes through the per-
forated false bottom, the space beneath being occasionally cleaned out, by a
powerful current of clean water injected into it. The bottom of the space
beneath the false bottom may be inclined downwards towards the end at which
the grain enters, and it may be provided with a sluice door at that end for
cleaning it. The dipping chain for lifting the grain out of the water may be
dispensed with, the screw shaft being set at an angle, so as to rise out of the
water at one end and deliver the grain over the edge of the trough, the trough
being shaped to correspond to this. The end of the shaft which rises out of the
water may have a greater number of blades fitted to it than at the lower part,
or it may be made at the upper end with a continuous screw thread, to insure
the delivery of the grain over the edge of the trough. The grain is delivered
into a duct, with a wire gauze or perforated bottom, in order that the
water may drain off'; or, instead of the herein-before mentioned plans, the
trough may be made with two inclined sides, and the screw shaft may be
placed vertically, in or near the centre, being encompassed by a cylindrical
casing of perforated metal. At the side at which the grain is introduced and
the used water carried off, a partition is fitted across the trough near the
cylinder of the screw, and passes down to within a short distance of the bottom.
The grain passes under this partition, leaving the scum and light foreign matters
behind it on the surface of the water behind the partition. On issuing from
below the partition, the grain is carried up to the surface by the action of the
screw shaft, stones and heavy foreign matters falling to the bottom, whence
they are taken periodically by suitable doorway. The screw delivers the
grain upon a riddle, lying across the front end of the tank. Various descrip-
tions of riddles may be employed; and the fresh water supplied to the tank
may be introduced above the riddle to give the grain a final washing.
In drying the grain a modification of the well-known hydro-extractor is
employed. In this arrangement, a thin-bladed screw is fitted inside the
revolving drum, and this screw is geared so as to revolve at a slightly different
rate from that of the drum. This differential motion of the screw gradually
traverses the grain from ono end to the other of the drum, so that the of cration
can be carried on continuously, and the relative speed of the drum and screw
can be regulated so as to deliver the grain in a perfectly dry state.
In the new grinding arrangements, the improvements relate, in the first

page_text: place, to the drawing of air through the upper stone of a pair of millstones,
whether it be the runner or not. For this purpose, the upper stone is made
with a number of openings completely through its thickness, which openings
may be conveniently formed by leaving space between the "burrs" or
segments of which the stone is built up. The top of the stone is covered
with a casing communicating with an air-drawing apparatus; or if the
upper stone is stationary this casing is simply fixed to it, whilst, if it is the
runner, the casing is fixed in contact with the stone; or a loose joint may be
formed between the two, it being inmaterial to make the joint perfect. In
connection with this system of working, the eye of the stone is to be covered in
and provided with an adjustable entrance for air, so that this can be regulated
with accuracy. The air may be exhausted or drawn through the stone by
ineans of a screw fan revolving immediately above the stone.
The said improvements in grinding arrangements further relate to a system
of duplex concentric grinding stones, wherein an outer pair of annular stones is
employed in combination with an inner pair of stones of the ordinary description,
but smaller than usual; the two running stones are carried by the same shaft,
and revolve together. The grain is fed into the eye of the central stones, by
which it is proposed to be merely rough ground; it is delivered by them into
an annular space between the two stones, upon a perforated screen, inclined up
and outwards, forming a portion of an inverted conc. The upper edge of this
screen coincides with the level between the outer stones; and the centrifugal
motion of the stones, the lower stones being the runners, causes the imperfectly
ground grain to rise up the inclined screen and enter between the two outer
stones, whilst the portion already sufficiently ground falls through the per-
forations of the screen; or instead of this plan the ground or partly ground
grain from the central stones may be allowed to fall down the annular space
between the two pairs of stones, the outer stones being fed from above. This
system may be adopted where the upper stones are the runners, as well as
where the lower ones are so, and the grain may be thoroughly ground by both
pairs of stones, if desired. The system of ventilating the stones, already herein-
before described, can also be applied to the duplex concentric stones.
In dressing flour, arrangements are made for the introduction of air at the
longitudinal centre of the flour-dressing machine. For this purpose a portion
of the dressing drum or cylinder is cut away at the centre, and a casing is intro-
duced into the opening so made; this casing is fixed, and carries a bearing for
the centre of the shaft of the revolving brushes, thereby considerably reducing
its tendency to vibrate. The air is admitted to the casing by a side entrance, or
it may be forced in by a blowing machine, if necessary. The two separated ends

page_text: of the drum are driven at the same rate by suitable gearing. This arrangement
permits the employment of a much greater speed of the revolving brushes,
which will improve the action of the machine, by drawing in more air, and
thereby blowing the flour through the wire gauze more effectually, and so
reduce the wear on the brushes: or arrangements may be made for introducing
SPECIFICATION. in pursuance of the conditions of the Letters Patent, filed
1
by the said John Currie and Robert Young in the Great Seal. Patent
Office on the 9th December 1854.
TO ALL TO: WHOM THESE PRESENTS SHALL COME, we, JoпN
CURRIE, of Glasgow, in the County of Lanark, North Britain, Miller, and
ROBERT YOUNG, of the same Place, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of June, in the year of our Lord One
thousand eight hundred and fifty-four, in the seventeenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
John Currie and Robert Young, Her special license that we, the said John'
Currie and Robert Young, our executors, administrators, and assigns, or such
others as we, the said John Currie and Robert Young, our executors, adini-
nistrators, or 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 TREATMENT AND GEINDING OF GRAIN AND
THE PRODUCTS THEREOF," upon the condition (amongst others) that we, the said
John Currie and Robert Young, by an instrument in writing under our hand
and seal, or under the hand and scal of one of us, 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.
3
• NOW KNOW YE, that we, the said John Currie and Robert Young, do
hereby declare the nature of our said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying Draw-
ings, and to the letters and figures marked thercon, that is to say :-
Our said Invention relates, primarily, to the washing and cleansing of

page_text: Egyptian wheat and other grain, by passing it from a screen or riddle into
one end of a long narrow water trough, having a perforated false bottom of
semicircular section. Above this is horizontal longitudinal shaft with a
series of inclined blades or paddle arms upon it, such arms being fitted to
work just clear of the false bottom, and at a considerable depth beneath the
water surface. The paddles are adjustable at any angle with their axis of
revolution, and as they revolve they agitate the grain in the water, and
convey it to the opposite or delivery end of the trough, whence it is lifted out
by a dipping chain of perforated buckets, by which chain also the paddle shaft
is itself driven. The clean washing water enters the trough at the end where
the grain is taken out, and a constant currant flows off at the end where the
grain enters, carrying with it the floating refuse, whilst the heavier foreign
matter escapes through the perforated false bottom, the space beneath being
occasionally cleaned out by a powerful current of clean water injected into it.
The bottom of the space beneath the false bottom may be inclined downwards
towards the end at which the grain enters, and it may be provided with a
sluice door at that end for cleansing it. By another modification, the dipping
chain for lifting the grain out of the water may be dispensed with, the screw
shaft being set at an angle, so as to rise out of the water at one end and
deliver the grain over the edge of the trough, the trough being shaped to
correspond to this arrangement. The end of the shaft which rises out of the
water may have a greater number of blades fitted to it than at the lower part,
or it may be made at the upper end with a continuous screw thread, to insure
the delivery of the grain over the edge of the trough. The grain is delivered
into a duct; with a wire gauze or perforated bottom, in order that the water
may drain off; or, instead of the herein-before mentioned plans, the trough
may be made with two inclined sides, and the screw shaft may be placed
vertically in or near the centre, being encompassed by a cylindrical casing of
perforated metal. At the side at which the grain is introduced and the used
water carried off, a partition is fitted across the trough near the cylinder of the
screw, and passed down to within a short distance of the bottom. The grain
passes under this partition, leaving the scum and light foreign matters behind
it on the surface of the water behind the partition. On issuing from below
the partition, the grain is carried up to the surface by the action of the screw
shaft, stones and heavy foreign matters falling to the bottom, whence they are
taken periodically by a suitable doorway; or the partition may be dispensed
with, the action of the screw shaft being sufficient to draw the grain into the
cylinder. The screw delivers the grain upon a riddle or screen lying across
the front end of the tank. Various classes of riddles may be employed, and

page_text: the fresh water supplied to the tank may be introduced above the riddle, to
give the grain a final washing.
In drying the grain, a modification of the well-known bydro-extractor or
centrifugal drying apparatus is employed. In this arrangement, a thin-bladed
screw is fitted inside the revolving drum, and this screw is geared so as to
revolve at a slightly different rate from that of the drum. This differential
motion of the screw gradually traverses the grain from one end to the other
of the drum, so that the operation can be carried on continuously, and the
relative speeds of the drum and screw can be regulated so as to deliver
the grain in a perfectly dry state.
In the new grinding arrangements, the improvements relate, in the first
place, to the drawing of air through the upper stone of a pair of millstones,
whether it be the runner or not. For this purpose, the upper stone is made
with a number of openings completely through its thickness, which openings
may be conveniently formed by leaving spaces between the "burrs" or seg-
ments of which the stone is built up. The top of the stone is covered with a
casing, communicating with an air-drawing apparatus, and if the upper stone
is stationary, this casing is simply fixed to it, whilst, if the upper stone is the
runner, the casing is fixed in contact with the stone, or a loose joint may bo
formed between the two, it being unnecessary to make the joint perfect. In
connection with this system of working, the eye of the stone is to be covered
in and provided with an adjustable entrance for air, so that this can be regu-
lated with accuracy. The air. may be exhausted or drawn through the stone
by means of a screw fan revolving immediately above the stone.
The said improvements in grinding arrangements further relate to a systeın
of duplex concentric grinding stones, wherein an outer pair of annular stones
is employed in combination with an inner pair of stones of the ordinary kind,
but smaller than usual. The two running stones are carried by the same
shaft, and revolve together. The grain is fed into the eye of the central stones,
by which it is proposed to be merely rough ground; it is delivered by them
into an annular space between the two stones, upon a perforated screen inclined
up and outwards, forming a portion of an inverted conc. The upper edge of
this screen coincides with the level between the outer stones; and the centrifugal
motion of the stones, the lower stenes being the runners, causes the imper-
fectly ground grain to rise up the inclined screen, and enter between the two
outer stones, whilst the portion already sufficiently ground falls through the
perforations of the serven. Or instead of this plan. the ground or partly
ground grain from the central stones may be allowed to fall down the annular
space between the two pairs of stones, the outer stones being fed from above.

page_text: This system may be adopted where the upper stones are the runners as well as
where the lower ones are so used, and the grain may be thoroughly ground by
both pairs of stones, if desired. The system of ventilating the stones, already
herein-before described, can also be applied to the duplex concentric stones.
In dressing flour, arrangements are made for the introduction of air at the
longitudinal centre of the flour-dressing machine. For this purpose a portion
of the dressing drum or cylinder is cut away at the centre, and a casing is
introduced into the opening so made; this casing is fixed, and carries a bear-
ing for the centre of the shaft of the revolving brushes, thereby considerably
reducing its tendency to vibrate. The air is admitted to the casing by a side
entrance, or it may be forced in by a blowing machine, if necessary. The two
separated ends of the drum are driven at the same rate by suitable gearing.
This arrangement permits the employment of a much greater speed of the
revolving brushes, which will improve the action of the machine, by drawing
in more air, and thereby blowing the flour through the wire gauze more
effectually, and so reduce the wear on the brushes. Or arrangements may
be made for introducing air at two or more points in the drum's length, if
desirable.
And in order that our said Invention may be properly understood, we shall
now proceed to describe the several explanatory Figures on the two Sheets of
Drawings hereunto attached. Figure 1, on Sheet 1 of the Drawings, is a
transverse vertical section, and Figure 2 is a vertical longitudinal section, of
one modification of our improved grain-washing machine, wherein a hori-
zontal screw paddle shaft is employed as the essential working apparatus:
Figure 3, on the same Sheet of Drawings, is a vertical longitudinal section
of the modification of our grain-washing machine, in which the screw
paddle shaft is disposed in an inclined position. This Figure also compre-
hends a vertical section of our improved centrifugal grain-drying machine, as
working in connection with the screw paddle shaft. Figure 4, on Sheet 2 of
the Drawings, is a vertical longitudinal section, and Figure 5 is a plan, of the
modification of our improved grain-washing machine, in which a vertical screw
paddle shaft is used: Figures 6 and 7, also on Sheet 2 of the Drawings, are
respectively a vertical section and a plan of a pair of grain-grinding stones,
shewing the manner of carrying out our improved system of ventilation.
Figures 8 and 9, on the same Sheet, are respectively a vertical section and
a plan of our improved arrangement of duplex concentric grinding stones.
Figure 10 is a vertical longitudinal section of a portion of a flour-dressing
drum, fitted with our improved arrangement for admitting air into the drum
near its longitudinal centre; and Figure 11 is an elevation of a flour-dressing

page_text: drum, fitted with a slightly modified form of apparatus for effecting the same
object, and which, does not necessitate the dividing of the drum. Figure 12
is a transverse section of the drum, showing the internal structure of the air-
introducer; Figure 18 being a side elevation thereof as detached from the
drum. The grain-washing machine, represented in Figures 1 and 2 of the
Drawings, consists of a long tank A, rectangular in plan, but with a slightly
inclined bottom B, to facilitate cleansing out, this cleansing being effected
through the sluice door C. At a slight elevation above the bottom is fitted a
semi-cylindrical partition D, of perforated metal or of some similar permeable
material, disposed horizontally along the tank; above this partition revolves a
horizontal shaft E, carrying a number of inclined or screw blades or paddles F,
arranged to revolve just clear of the partition D. The grain to be washed is
introduced into the tank at G, whilst fresh water enters by the pipe II at the
opposite end, flowing off at I, and carrying with it the floating refuse. The
screw shaft agitates the grain, and conveys it towards the opposite or delivery
end of the tank, during which process the heavier foreign inatters pass through
the perforated partition D. The grain is lifted out of the tank after being
washed by the dipping chain of perforated buckets J. This chain is passed
round, a pulley K on the end of the screw paddle shaft E, and it passes up
in an, inclined direction to the upper pulley L, by means of which last the
chain is driven, whilst the chain itself serves as a connection for driving the
screw paddle shaft E. The washed grain is delivered at M as the buckets J
turn over in passing round the pulley L. In the modification of grain-
washing machine represented in Figure 3, the bottom B of the tank A is
inclined at a considerable angle, the perforated partition D as well as the
screw paddle shaft E being also inclined and parallel to it. The paddles F
are carried upon the shaft considerably above the water level, and such of
them as are above the water have a greater inclination given to them, so as to
carry up the grain more rapidly than the paddles below. The perforated par-
tition D extends up as far as the paddles, and after the grain rises above the
water level the water drains off from it through the partition. The grain is
introduced at the lower end of the tank, and is delivered at G into the drying
apparatus, which we shall herein-after describe; any kind of drying apparatus,
however, may be used in connection with this apparatus. The screw paddlo
shaft E is carried in a bearing H in the lower end of the tank, and in another
bearing in a pendant bracket I at the upper end of the shaft. The shaft hins
keyed on its extreme upper end a bevil wheel J, in gear with a bevil wheel K,
on a horizontal shaft L, which transmits the motion from any primo mover,
and drives the washing apparatus. In the modification of grain-washing

page_text: apparatus represented in Figures 4 and 5 of the Drawings, the tank A
is mado with two inclined sides B, and in or near the centre is placed a
vertical cylinder C, of perforated metal, or other permeable material, the lower
portion of which is made conical. In the centre of this cylinder is placed
the vertical shaft E, revolving in the footstep bearing F, and driven from above.
This shaft is furnished with a number of inclined or screw blades or paddles
G, and by its rotation it agitates the contents of the tank, carrying the grain
upwards through the cylinder, whilst stones and other heavy foreign matters
fall to the bottom of the tank. The grain enters the cylinder by a side opening
and duct at H, the floating refuse being carried away by the water which flows
off at I, being introduced at the other end of the tank. To the top of the
cylinder C is fitted a strip of wire gauze or other suitable material J, of a more
casily permeable nature than that of the cylinder C, to allow the water raised
by the action of the screw paddle shaft to flow off more freely when it reaches
this point. This strip of wire gauze J is formed with an opening and spout at
K, through which the grain is delivered upon a riddle L; here the water
drains off from the grain, and the latter is gradually thrown forward by the
motion given to the riddle by a pair of cranks M in the usual manner, the
grain being finally delivered over the front edge of the riddle at N into a
proper receiver. The fresh washing water may be poured into the tank above
the riddle L, so as to give the grain thereon a final washing, or, if this is not
requisite, the water may be introduced below it.
We shall now proceed to describe our improved grain-drying machine, which
is represented in Figure 3, on Sheet 1 of the Drawings, as combined with our
inclined screw washing machine; it is, however, obviously applicable for drying
any grain without reference to the particular mode herein supposed to be
employed in washing such grain. This drying machine consists of a cylindrical
casing M, inside which revolves the cylinder N, of wire gauze; this cylinder N
is mounted on a number of ribs O, which hang down at right angles from the
top piece or disc P, keyed upon the vertical tubular shaft Q. The top piece P
is formed with an annular opening or mouth R, through which the wet grain is
admitted to the interior of the wire gauze cylinder N. The grain first falls upon
an annular plate S, the rotatory motion of which throws it outwards until it
descends between the outside of the plate S and the inside of the wire gauze
cylinder N. The annular plate S is carried by a number of ribs T, standing
up from the radiating arm piece U, fast on the vertical shaft V, which passes
up through the tubular shaft Q, supporting this last by means of the collar W.
The ribs T have fixed upon theni a continuous screw thread, or what will
answer the purpose as well, a series of slightly, inclined blades X: The

page_text: shaft V revolves in upper and lower end bearings Y, and is driven by means
of the pulley Z fast on it near its upper end. The tubular shaft Q extends
upwards to within a short distance of the pulley Z, and has fast on its
upper end a pulley a, by means of which it is driven, the driving power
being transmitted to the two pulleys Z, a, by belts from pulleys upon a
parallel shaft, not shewn in the Drawings. The wire gauze cylinder N
and the screw blades X are both driven in the same direction but at slightly
diffirent velocities, in such a manner that the latter slowly traverse round the
inside of the cylinder, and working just clear of it, gradually screw down the
grain as it undergoes the drying process due to the centrifugal action of
the wire gauze cylinder. A cone pulley-driving arrangement is used in con-
nection with the pulley a, so that the rate of revolution of the tubular shaft Q
and its permeable cylinder N may be varied, in order that the grain may be
passed through it at a proportionately quicker or slower rate. The dried grain
passes off down the cone 6 and duct c, the former fitting the lower edge of the
wire gauze cylinder N, and the water is prevented from entering this conc
from the outside of the cylinder by the protecting flange d being received
instead, in the annular space c, whence it is drawn off by a pipe or other
outlet.
In Figures 6 and 7, on Sheet 2 of our Drawings, is represented our im-
proved arrangement for obtaining a draught of air between the grinding
surfaces of a pair of millstones. In the present instance, the upper stone A is
stationary, the lower one B being the runner. A series of annularly disposed
openings C are made vertically through the upper stone A, these openings
being conveniently formed between the "burrs" or segments of which the
stone is built up. These openings are covered by an anuular casing D, which
forms a continuous connecting channel, and communicates by a pipe E with
an exhausting fan or apparatus for producing a draught; the apparatus
used for drawing air from the casing F of the stones will also answer for
drawing the air through the openings C and the pipe E. The air finds its
way in between the stones at the eye G, and this eye may be furnished with
an adjustable cover, for the purpose of regulating the draught. As already
stated, this system of ventilation by exhausing the air may be applied to all
arrangements of grinding stones. In Figures 8 and 9, also on Sheet 2 of the
Drawings, which represent our improved arrangement of duplex concentric
grinding stones, the inner pair of stones A, B, are of the ordinary kind, whilst
the outer pair C, D, are annular, or formed with central openings, sufficiently
large to contain the central stones A, B, and also to leave a narrow annular
space E between the two pairs of stones; either the upper or lower stones

page_text: may be made the runners, but in the present instance we have made the lower
stones the runners, the upper stones A and C being stationary. The outer
stone C'is fixed and adjusted in the usual way by means of the three adjusting
screws F. The inner stone A has three brackets G bolted to it, by means of
which it is supported upon the outer stone. C, which has a ring H fixed upon its
inside edge for the purpose. The stone A is adjusted as to its level by means
of the screws I in the brackets G, and these screws rest upon slightly inclined
surfaces upon the ring H. These inclines are all in the same direction, so that
by turning the stone A it may be raised or lowered without altering its level.
A pair of screws are carried by the ring II, so as to act on one of the
brackets G, for the purpose of effecting the adjustment. In arranging the
stones for working, the outer stone C is first accurately adjusted, and then
the inner, stone A is adjusted just as if the stone C were a fixture. The grain
is introduced in the usual manner at the central eye K, and is rough ground
by the two inner stones A, B. On issuing from between these stones, the
roughly ground grain falls upon a strip of wire gauze L, extending across the
space E between the stones B and D, being inclined upwards towards the outer
stone D. The centrifugal action due to the rotation of the stones B, D, causes
the roughly ground grain to rise up the inclined wire gauze screen E. and enter
between the outer stones C, D, such portions as are sufficiently ground passing
through the wire gauze, and falling to the bottom of the casing M of the stones.
A brush N is fixed to one of the brackets of the stationary stone A, and
serves to clear the wire gauze L as it revolves beneath it. The outer stones
C, D, are in closer contact than the inner stones A, B, and it passing between
them the grain: receives its final grinding treatment. The, stones B and D
are supported upon the shaft O in the usual manner, the arms P of the rhyne
passing completely through the inner stone B, and entering to the extent of
a few inches into the outer stone D. A number of blades Q are fixed upon
the under side of the stonie D, to act as fan blades; for drawing the air through
the wire gauze screen L dowai the annular space E between the two pairs
of stones, this action greatly assisting the separation of the flour which is
sufficiently ground by the inner stones A. B. The system of ventilation,
described in reference to Figures 6 and 7 on Sheet 2 of the Drawings, may
also be applied to this arrangement of duplex'stones.
In proceeding to describe our improvements in flour-dressing machines. as
delineated in Figures 10, 11, 12, and 13. on Sheet 2 of the Drawings, we may
remark, that in ordinary dressing machines the air drawn in at each end of the
wire gauze drum by the fan action of the dressing brushes does not act with
sufficient uniformity throughout the length of the drum, being very feebly blown

page_text: through the wire gauze at the longitudinal centre, whilst at the ends of the 'drum
the blast is much greater.. The object of this portion of our Invention is to
remedy this defect, by providing a means of admitting air at or near the longi-
tudinal centre of the drum, or at other points in the length of the drum, so as
to equalise the blowing action throughout the wire gauze. In the modification
represented in Figure 10, the wire gauze drum is in two portions A, B, which
are supported at the outer extremities, in the usual way; and are made to rotate
at a slow uniform rate by means of pinions, fast upon the shaft C, and in gear
with toothed rings or wheels fixed on the outer ends of the drums A, B. . The
space which separates the two portions A, B, of the drum is occupied by a
casing D, which is supported by flanges upon the inclined girders or beams E
at the sides of the drum. The upper end of the casing D is provided with an
inlet duct F, by which the air enters the interior, being forced in by suitable
blowing apparatus, if necessary. Advantage is taken of the casing D to intro-
luce an intermediate support for the shaft G, which carries and drives the
dressing brushes H. This support for the shaft consists of a bearing I, carried
by a cross plate J, cast upon the casing D, the bearing being susceptible of
adjustinent as to height by means of the screw nuts.K. The inside of tho
casing D is made flush with the inside of the drum at L, and the flour descends
through from the upper to the lower portion of the dressing drum without im-
pediment. In Figures 11, 12, and 13, is represented a modified arrangement, in
which the drum is not divided; the air is admitted at or near the longitudinal
centre of the drum A, between two of the circumferential metal ribs B. The
wire gauze is removed from this space and a casting is introduced, which is
formed with oblong channels C, extending inwards for a short distanco
towards the centre of the drum. These channel pieces are cast upon arms .D,
formed with a boss E, embracing the shaft F, on which the dressing brushes are
carried. The boss E with its arms and channel pieces is in two pieces, formed
with flanges, by means of which it is bolted upon the shaft F, brasses being
inserted to reduce the friction. The spaces G between the channels C arc
covered with metal, and the flour passes from the upper to the lower portion
of the drum through the internal spaces H between the channels. These
details are embraced by a stationary casing I, bolted down
flanges Jupon
the girders running down at the sides of the drum. The two ribs Baro
turned truly circular, and rest upon the casing I, which serves as an inter-
mediate support for the dressing drum, and also for the shaft F, through
the
of the channel picce C, D, E. The air enters the casing I. by an
agency
opening K at the bottom, and also by an inlet duct L, through which last it
inay be forced by blowing apparatus, if necessary. The air enters the channels

page_text: C, and finds its way to the interior of the drum, the slow rotation of this
drum not offering any impediment. It is obvious that two or more of these
ventilating pieces may be introduced into the length of the dressing drum, so
as to equalise the blowing action still more, if necessary; and in cases where
arrangements are adopted for admitting the air at more than one intermediate
point in the length of the drum, the inlet pieces may be formed with or with-
out the supporting bearing for the central shaft, accordingly as this may
be deemed necessary in practice.
Having now described and particularly ascertained the nature of our said
Invention, and the manner in which the same is or may be used or carried
into effect, we may observe, in conclusion, that we do not confine or restrict
ourselves to the precise details or arrangements which we have had occasion to
lescribe or refer to, as many variations may be made therefrom without
deviating from the principles or main features of our Invention; but what
we consider to be novel and original, and therefore claim as the Invention
secured to us by the herein-before in part recited Letters Patent, is,-
First, the general arrangement and construction of machinery, apparatus,
or means for the treatment and grinding of grain and the products thereof, as
herein-before described.
Second, the system or mode of washing grain, by means of a revolving
shaft, working within a perforated semi-cylinder or within a cylinder, and
furnished with screw or inclined blades or paddles, such shaft being set in a
tank in a horizontal, inclined, or vertical position, whilst the washing water is
made to flow through the tank in a direction contrary to the course of the
grain, and to carry off the floating refuse, the heavy foreign matters falling to
the bottom of the tank, as herein-before described.
Third, the application and use in centrifugal grain-drying machines of
screw or inclined blades, revolving at a slightly different rate from that of the
rotating cylinder, and gradually and continuously conveying the grain through
the cylinder, thereby enabling the apparatus to receive the wet grain, and
deliver it as it becomes dry in a continuous manner, as herein-before
described.
Fourth, the system or mode of ventilating grain-grinding or mill stones, by
exhausting the air through apertures in the upper stone, the air being admitted
at the eye or centre of the stone, as herein-before described.
Fifth, the system or mode of arranging two pairs of grain-grinding stones
concentrically, one pair being in the form of annular stones, arranged outside
a pair of stones of the ordinary kind, as herein-before described.
Sixth, the system or mode of grinding grain by means of two pairs of

page_text: concentric stones, wherein the grain is first roughly ground by the inner pair
of stones, and is then re-ground more finely by the outer pair of stones, as
herein-before described.
Seventh, the system or mode of constructing cylindrical flour-dressing
machines with inlet spaces or passages for air at one or more intermediate
points in the length of the cylinder, as herein-before described.
In witness whereof, I, the said John Currie, on behalf of myself and of
the said Robert Young, have hereunto set my hand and seal, this
Seventh day of December, in the year of our Lord One thousand eight
hundred and fifty-four.
JOHN CURRIE. (L.S.)