IMPROVEMENTS IN MILLS
Year: 1882

page_text: LETTERS PATENT to Robert Young of Glasgow, in the County of Lanark,
North Britain, Engineer, for an Invention of "IMPROVEMENTS IN MILLS For
PROVISIONAL SPECIFICATION left by the said Robert Young at the Office
of the Commissioners of Patents on the 18th November 1882.
ROBERT YOUNG, of Glasgow, in the County of Lanark, North Britain, Engineer,
"IMPROVEMENTS IN MILLS FOR GRINDING GRAIN
"
This Invention has for its object to improve and cheapen the manufacture of
flour by employing a novel construction of mills for grinding wheat or other
grain.
In carrying out the Invention two disks of chilled castiron or other suitable
metal are employed such disks being of a concave or dished form excepting a narrow
annular flat part at the circumference. The disks are fixed upon tubular shafts
which are in the same line, and they are placed with their concavities facing each
other so as to form a hollow between them with the flat annular parts nearly in
contact. The grain may be fed in through one of the shafts and the disks are
driven at speeds sufficient to throw the grain between the annular circumferential
parts which constitute the grinding parts and which are suitably formed for that
purpose with grooves or other grinding surfaces. The disks are both driven in the
same direction but one is driven at a greater speed than the other so as to produce
the required grinding action, the action so obtained being somewhat like that
produced by rollers but more advantageous in consequence of the effective breadth
of surface being greater. The disks may be placed with their shafts in a horizontal
or inclined position but the vertical position is considered preferable. A casing is
fixed round the disks to receive the ground grain with a duct or ducts to lead it
away; and two or more pairs of the disks may be combined so that the grain may
be passed through the several pairs in succession.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Robert Young in the Great Seal Patent Office on the 17th May
1883.
ROBERT YOUNG, of Glasgow, in the County of Lanark, North Britain, Engineer,
"IMPROVEMENTS IN MILLS FOR GRINDING GRAIN
°
"
My said Invention bas for its object to improve and cheapen the manufacture of
flour by employing a novel construction of mills for grinding wheat or other
grain.
In carrying out my Invention two disks of chilled castiron or other suitable
metal are employed, such disks being of a concave or dished form, excepting a
narrow annular flat part at the circumference. The disks are fixed on shafts which
are in the same line, and they are placed with their concavities facing each other
so as to form a hollow between them with the flat annular parts nearly in contact.
The grain may be fed in through one of the shafts, made tubular for the purpose,
and the disks are driven at speeds sufficient to throw the grain between the annular
circumferential parts which constitute the grinding or dividing parts and which
are suitably formed for that purpose with grooves or other grinding or dividing
surfaces. The disks are both driven in the same direction but one is driven at a
greater speed than the other.so as to produce the required grinding or dividing
action
ד.
The disks may be placed with their shafts in a horizontal, vertical, or inclined
position. A casing is fixed round the 'disks to receive the ground or divided grain
with a duct or ducts to lead it away; and two or more pairs of the disks may be
combined so that the grain may be passed through the several pairs in succession.
Thus in the first pair of disks I prefer to have the acting surfaces such as, if
possible, to split or divide the wheat, grains longitudinally, and when the grains
are thus divided they may be subjected to a cleaning sifting or dressing process
which will separate fine or crease dust and other impurities more easily and satis-
factorily than can be done at a subsequent stage after the grains have been more
crushed or ground. The acting surfaces of the second pair of disks may be such as
to transversely divide the half grains from the first pair, and other pairs of disks
may be arranged for producing more minute division of the grain at each successive
stage, the grain being passed through cleaning, sifting or dressing machines
between the stages as often as may be considered desirable.
And in order that my said Invention and the manner of performing the same
may be properly understood I hereunto append two sheets of explanatory drawings
to be hereinafter referred to and representing modifications of my improved
apparatus.
Figure 1, on sheet 1 of the accompanying drawings is a plan of one of my
improved disk mills with the shafts horizontal; figure, 2, being a corresponding
longitudinal vertical section and figure, 3, an end elevation. Figure, 4, on sheet, 2,
is an elevation of a modification in which the shafts are vertical; and figures 5
to 10 are enlarged diagram representations of portions of the grinding or dividing
surfaces. In these drawings the same reference numerals are used to mark the
same or like parts wherever they are repeated.
In the machine shown in figures 1, 2, and 3, the framing consists of an upper
horizontal frame, 11, supported on pillars, 12, which are fixed on a bed frame, 13.
On the bed frame, 13, are bearings, 14, for the first motion shaft, 15, which has on
it fast and loose pulleys, 16, for a driving belt, and also two pulleys, 17, 18, from
which motion is transmitted by driving belts, 19, 20, to pulleys, 21, 22, on

page_text: shafts, 23, 24, carried each in two bearings, 25, upon the upper frame, 11. The
two shafts, 23, 24, are in the same line and have disks, 26, 27, fixed on their inner
ends, these disks being made with concave central parts and with annular parts
near the circumference which annular parts are grooved or otherwise formed with
surfaces suitable for acting in the desired manner on the grain. To insure
coincidence of the axes of the disks sockets are formed in the inner ends of the
shafts, 23, 24, and a pin, 28, is placed in the sockets with washers between its
ends and the ends of the sockets in one of which a small block of rubber is placed.
For adjusting the shafts, 23, 24, with their disks, 26, 27, towards each other, the
outer ends of the shafts bave end bearing pieces, 29, applied to them with hand-
wheel screws by means of which to adjust them. For the purpose of feeding the
grain into the hollow space between the disks, 26, 27, one of them, 26, is made
with openings, 30, between its circumferential part and its centre and is made with
a flat annular surface externally against which there is adjusted an annular
plate, 31, in the upper part of which is formed a passage to lead the grain from a
feeding hopper, 32, to the openings, 30, in the disk. The plate, 31, is made in two
halves which after being placed in position one being entered from below and the
other from above are bolted together by flanges formed on them for the purpose;
and then the plate is adjusted and secured to one of the bearing blocks, 25 by
ineans of screw bolts and lugs, 33, made with elongated holes. The disks 26, 27,
are enclosed in a casing, 34, shown in figure, 3, and partly in figure, 2, but not in
figure, 1, and this casing is provided with an inclined duct to lead away the split
or reduced grain. The best velocities for the disks, 26, 27, must be determined by
trial but I believe that good results will be obtained with one disk running at 300
and with the other at 280 revolutions per minute, and the driving pulleys, 17, 18,
must be proportioned relatively to the pulleys, 21, 22, on the disk shafts, 23, 24, so
as to give the difference of velocities indicated or whatever difference is found to
be best in practice. With the view of avoiding disadvantage from the shortness
of the driving belts, 20, 19, tightening pulleys, 36, 37, are arranged to bear upon
them, these pulleys being held by forked levers centered on the upper frame, 11,
and being drawn against the belts by rubber springs, 38.
In the modification shown in figure, 4, the disk shafts, 23, 24, are placed
vertically being held in bearings, 25, upon a vertical frame, 39, which is formed
with a base, 40, and is also provided with bearings, 41, 42, for a vertical driving
shaft, 43. This shaft, 43, is driven by means of a belt pulley, 44, and drives the
disk shafts, 23, 24, by pairs of suitably proportioned spur wheels, 45, 46. The
upper disk shaft, 24, is made tubular and the grain is fed in through it from a
hopper, 32.
Figure, 5, is a face view of a portion of the annular acting surface of one of the
disks. This surface has radial grooves formed on it of the shape which will be under-
stood from figures, 6, and 7, showing respectively the inner and outer ends of the
grooves. The width of each groove is slightly less than the ordinary length of a
grain of wheat, and the inner end of each groove is slightly flared or rounded to
facilitate the entrance of the grains. As the grains cannot get into the grooves
crossways they must enter lengthways, and even if a grain reaches the entrance to
a groove in a cross position the differential motion of the disks will immediately
cause it to turn and enter lengthways. Then whilst the centrifugal force due to
the rotation is causing the grains to move outwards through the grooves the
differential motion of the disks will cause them to be split longitudinally. The
form of acting surface shown figures, 5, 6, and 7, is intended for the pair of
disks to which the grain is first subjected, whilst the form of acting surface which
I believe to be advantageous for the pair of disks to which the split and cleaned
grain is to be subjected at the second stage is shown in figures, 8, 9, and 10,
Figures 8, and 9, show the two acting faces as turned from each other and
figure, 10, is a radial section. The acting surfaces are formed with radial grooves;
but in one face (figure 8) the ridges between the grooves are as it were cut away
so as to form a flat annular surface between the inner and outer parts, whilst on

page_text: the face of the other disk the ridges are made to project so as to enter the middle
part of the other surface. The acting surfaces of the disks to be used for the
subsequent stages of the reduction of the grain must of course be made with finer
grooves and the grooves may be made to run in other than radial directions.
Having thus particularly described my said Invention and the manner of
performing the same I have to state that I do not restrict myself to the precise
details herein described or delineated but that what I believe to be novel and
original and claim as the Invention secured to me by and in terms of the herein-
before in part recited Letters Patent is :-
1. The arranging or combining together of the parts of mills for grinding grain
substantially in the improved manner herein before described, the grinding or
dividing action being effected by annular metal surfaces rotating in the same
direction but at different speeds.
2. The constructing of the grinding or dividing surfaces of the annular acting
parts of the mill disks substantially as and for the purposes herein before described
and more particularly with reference to figures 5, 6, and 7, of the accompanying
drawings.
3. The constructing of the grinding or dividing surfaces of the annular acting
parts of the mill disks substantially as and for the purposes hereinbefore described
with reference to figures 8, 9, and 10, of the accompanying drawings,
In Witness whereof I, the said Robert Young, have hereunto set my hand
and seal this fifteenth day of May in the year of our Lord One thousand
eight hundred and eighty-three.
Witness,
EDMUND HUNT.
Patent Agent.
Glasgow.
ROBERT YOUNG (L.S.)