IMPROVENIENTS IN MACHINERY FOR GRINDING
Year: 1852

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
BARNETT, late of Kingston-upon-Hull, but now of Beverley, in the County of
York, Grocer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of Great Britain, bearing date at Westminster,
the Eighth day of January, in the fifteenth year of Her said Majesty's reign,
did give and grant unto me, the said Thomas Barnett, my exors, admors, and
assigns, Her especial licence, full power, sole privilege and authority, that I,
the said Thomas Barnett, my exors, adññiors, and assigns, and every of them, by
myself, himself, and themselves, as by my and their deputy or deputies,
servants or agents, or such others as I, the said Thomas Barnett, my exors,
adñiors, or assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within that part
of the United Kingdom of Great Britain and Ireland called England, the
Dominion of Wales, and Town of Berwick-upon-Tweed, and in the Islands of
Jersey, Guernsey, Alderney, Sark, and Man, and also in all the Colonies and
Plantations abroad, in such manner as to me, the said Thomas Barnett, my
exors, adiñors, and assigns, or any of them, should in my or their discretion
seem meet, my Invention of "IMPROVENIENTS IN MACHINERY FOR GRINDING

page_text: WHEAT AND OTHER GRAIN;" in which said Letters Patent there is contained a
proviso that I, the said Thomas Barnett, shall particularly describe and ascer-
tain the nature of my said Invention, and in what manner the same is to be
performed, by an instrument in writing under my hand and seal, to be enrolled
in Her said Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said in part recited Letters Patent,
as, reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Barnett, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are described and ascer-
tained, with the aid of the Drawings annexed hereto, by the words, letters,
and figures, and in manner following:
But before describing the details of my Invention it may be proper to state
that my improvements in grinding have reference to the construction of mill
stones as ordinarily used, and to the grinding of all kinds of grain. My
objects are, firstly, to prevent the meal or flour from becoming unduly heated
and deadened or otherwise injured during the process of grinding; secondly,
to prevent the over-grinding or regrinding, as far as practicable, of any portion
of the meal or flour; and, thirdly, to obtain the greatest possible economy of
power in grinding a given quantity of grain. These objects I effect by con-
tinually separating and discharging from the stones a certain portion of flour
which is perfectly ground during their action before such portion has travelled
over their own surface and reached their outside or periphery, which is per-
formed in the manner following:-Through both the upper and under grinding
stones I cut or form holes or annular segmental spaces in such manner that when
the stones are in their working position the holes or spaces in each stone shall
respectively coincide. The face of that portion of the stones which extends
from the eyes of the stones to the holes or annular segmental spaces, I call
the first or inner grinding surface; and the face of that portion of the stones
which extends from these spaces to the outer periphery of the stones, I call
the outer grinding surface. The space or spaces in the lower stone I cover
with wire gauze placed nearly on a level with the grinding surface, but
generally rather below it.
Within the spaces formed in the upper stone I fix
brushes in such manner that they may press lightly on the surface of the wire
gauze fixed in the lower stone. The spaces in the upper stone I cover with
air boxes in such manner that as the stone revolves, air is received by their
wide ends and is forced down by the revolution of the stone upon the wire
gauze, so that with the aid of the brushes it carries through the gauze or
sieves the finest and already perfectly ground portion of the flour. The par-

page_text: tially ground meal being carried forward by the brushes, passes on to the
outer grinding surface where its grinding is finished, and it is discharged into
the meal spout.
I do not confine myself to any particular rule for dividing
the surface of the stones in respect of the area of the inner and outer grinding
surfaces, neither do I limit myself to any particular dimension, area, or number
of the spaces covered with wire gauze, nor to the form or position of the
spaces in the stones, as I may use two or more sets of spaces in a pair of
stones. I do not confine myself to the use of wire gauze as the material of
the sieves fixed over the spaces in the lower stone, but claim the use of any
other kind of sieve, of whatever material it may be composed, that will enable
me to separate and discharge from the stones that portion of the flour which
is perfectly ground before it has reached the outer grinding surface. Nor do
I limit myself to the use of any determinate size of mesh; but I may state
that I have found wire gauze of from 30 to 50 meshes to the inch to be
generally suitable and efficient for my purpose. In the accompanying Draw-
ings I have shewn the manner of effecting my improvements in detail, and
will now proceed to describe them.
Sheet 1. Figure 1, of which Figure 2 is a section, exhibits a casting or
framework to receive the French or buhr stones. (a) is the eye or central
space; (b, b,) are the spaces in which are fixed the buhrs that compose the
first or inner grinding surface; (c, c,) are the spaces in which are fixed the
brushes or wire gauze. The buhrs composing the outer grinding surface are
placed around the outside of this casting, and are bound together by a wrought-
iron hoop in the usual way, as shewn in Figure 3, which is a section of the
stone complete. Figure 4 is a plan of the under stone; (b) is the inner and
(d) the outer grinding surface; (e) is the wire gauze. Figure 5 is a plan of
the upper stone; (a) is the eye of the stone; (6) the inner, and (d) the outer
grinding surface; (F) the brushes. Figures 6 and 7 are plans of grey or
other whole stones; the spaces for the wire gauze and brushes are cut through
the solid stone. Figure 6 is the under stone; (b) is the inner and (d) the
outer grinding surface; (e) is the wire gauze; (9) is one of the frames on
which I fix the wire gauze. Two similar frames are shown in Figure 4, and
may be raised or lowered by means of adjusting screws. Figure 7 is the
upper stone; (a) is the eye; (b and d) the inner and outer grinding surfaces;
(f) the brushes.
Sheet 2. Figure 1 is a section of the mill corresponding with the line (a, b,)
in Figure 2 (the same letters refer to the similar parts in all the Figures of
both Sheets). (h, h,) are the air boxes with their open ends facing the direction
in which the upper stone revolves; two of the brushes (f, f) are shewn in

page_text: contact with the wire gauze (e, e,) as when at work; (i) is a spout coinciding
with the annular space in the stones, into which the fine or dressed flour is
discharged through the wire gauze; (j) is a spout into which the meal is
discharged when it has passed over the outer grinding surface; (k) is a casting,
within which the lower stone is fixed in the usual or other convenient manner.
Figure 2 is a plan of this casting, with the spouts (i and ) attached. (1, 1, 1, 1)
are screws to adjust and fix the lower stone laterally; (m, m, m, m,) are screws
on which the lower stone rests, and which serve to adjust it horizontally;
(n, n, n, n,) are flanges to rest on the floor of the mill room; (0, 0, 0, 0,) are
projecting pieces, which rest on columns, as shewn in Figure 4. Figure 3
is a section corresponding with the line (c, d,) in Figure 2, to show the
arrangement of the spouts (i and j). Figure 4 is a front elevation of the mill;
(p) is the hopper from which the stones are supplied with grain in the usual
manner; (h,h,) are the air boxes; (2) is the case enclosing the stones; (m, m,) are
the screws on which the lower stone rests; (i, i,) is the spout for the fine flour;
(i) is the orifice of this spout from which the flour is received into bags or
otherwise; (j, j,) is the spout for the meal or undressed flour. This spout, it
will be seen by referring to the sections, surrounds the spout i, and is arranged
in front of the mill, so as to deliver the meal from the two orifices, j, j. (r) is
the mill spindle, and (s, s,) are the wheels by which it is driven. Figure 5 is
a plan of the upper stone furnished with air boxes.
Having now described my said improvements in machinery for grinding
wheat and other grain, and in what manner the same are to be performed, I
declare that what I claim as my Invention is,-
First, the application of wire gauze, or of any other suitable kind of sieve,
to any orifice or opening in the lower stone for the purpose of separating the
perfectly ground flour from that which is unground or only partially ground,
and discharging the perfectly ground flour from the stones during the process
of grinding and before it has reached their outside or periphery.
Secondly, I claim the application of brushes for the purpose of facilitating
the said separation and discharge of the perfectly ground flour, and of
distributing the meal over the surface of the wire or other sieves fixed in the
lower stone, and brushing the meal towards the outer grinding surface.
In witness whereof, I, the said Thomas Barnett, have hereunto set
my hand and seal, this Seventh day of July, in the year of our
Lord One thousand eight hundred and fifty-two.
THOMAS (L.S.) BARNETT.

page_text: AND BE IT REMEMBERED, that on the Seventh day of July, in the
year of our Lord 1852, the aforesaid Thomas Barnett came before our
said Lady the Queen in Her Chancery, and acknowledged the Specifica-
tion aforesaid, and all and every thing therein contained and specified, in
form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made for that purpose.
Enrolled the Seventh day of July, in the year of our Lord One thousand
eight hundred and fifty-two.