AN IMPROVE- 'MENT OR IMPROVEMENTS IN MILLS FOR GRINDING
Year: 1858

page_text: LETTERS PATENT to Thomas, Averill, of Birmingham, in the County of
Warwick, Wholesale Tea Dealer, for the Invention of "AN IMPROVE-
'MENT OR IMPROVEMENTS IN MILLS FOR GRINDING."—A communication.
'MENT OR IMPROVEMENTS IN MILLS FOR GRINDING."-A communication.
Sealed the 21st January 1859, and dated the 23rd August 1858.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Averill in the Great Seal Patent Office on the
15th February 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
AVERILL, of Birmingham, in the County of Warwick, Wholesale Tea Dealer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of August, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Thomas Averill, Her special licence that I, the said Thomas Averill, my
executors, administrators, and assigns, or such others as I, the said Thomas
Averill, 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 " AN IMPROVEMENT OR IMPROVE-
MENTS IN MILLS FOR GRINDING,".. a communication from a foreigner residing
abroad, upon the condition (amongst others) that I, the said Thomas
Averill, 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 Averill, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
The said Invention consists of the improvement or improvements in mills
for grinding, herein-after particularly described and illustrated in the accom-
panying Drawing.
Figure 1 represents a side elevation of a mill-constructed according to the
said Invention; and Figure 2 represents a vertical longitudinal section of the
same; Figure 3 represents a plan (partly in section); and Figure 4 represents
a vertical transverse section of the said mill; Figures 5 and 6 represent a
detached portion of the same, as hercin-after explained. The same letters are
employed to indicate the same parts in the several Figures.

page_text: The grinding surfaces of the mill consist of a series of plates a, b, c, d, and e,
some of the said plates a, c, and e, being fixed, and the plates alternating with
the said plates a, c, and c, being moveable. The moveable plates are marked b
and d. Motion is given to the said moveable plates by means of a crank f
upon the axis g, which said axis is driven by the pulley h. The moveable
plates 6 and d are supported near the middle of their upper edges by means
of a pin i, passing through a slot k in the said plates. By the rotation of the
axis 9 and crank f the plates b, d, are drawn backwards and forwards upon
the pin i, and have besides an oscillating motion about the said pin i con-
sequent upon the alternate elevation and depression of those ends of the said
plates which are jointed to the crank f. Both the fixed and moveable plates
are corrugated, grooved, or otherwise roughened upon their surfaces, and the
grinding is effected by the matter to be ground being operated upon by the
corrugated, grooved, or roughened surfaces of the said plates. It will be seen
by an examination of Figures 3 and 4 of the Drawing, that each of the
moveable plates b, d, works between a pair of fixed plates. The size of the
corrugations or grooves on the plates may be varied to suit different articles to
be ground. One of the fixed plates is shown in elevation.in Figure 5, and in
vertical transverse section in Figure 6. The fixed plates ȧ, c, and e, are
supported by the pins i and 2, and on the tops of the legs of the machine.
m is the hopper in which the substance to be ground is supplied. The said
substance descends through the passage n, and passing through the slots o in
the plates, falls between the said plates." The lower edges of the slots o in thè
plates are notched, as represented at p in Figure 5. By thus notching the
said plates the breaking of the coarser particles of the substance to be ground,
and the introduction of their fragments between the plates, is effectually
secured. It will be seen by an examination of Figure 4, that the upper edges
of the plates, that is to say, the edges immediately below the slots.0, are the
thinnest parts of the said plates, and that the said plates gradually thicken
downwards, while those parts of the said plates which constitute the ribs or
projections are of uniform thickness. The grooves or depressions between the
ribs are thus deepest at top, and become gradually shallower towards the
bottom. The fineness or quality of the powder produced by the mill is
determined by the set screw q, by driving home which said set screw 9 the
distance to which the plates a, c, and e, can separate is determined. The
plates a, b, c, d, and e, are made of cast iron or other metal or alloy sufficiently
hard, and the frame or box in which the said plates work I prefer to make of
cast iron.
Although in the accompanying Drawing I have represented a mill having

page_text: but three fixed and two moveable plates, yet the number of the plates may be
varied to any desired extent. The mill may either be worked as a hand mill
or be driven by steam or other power; and although it is particularly adapted
for the grinding of grain, yet it may be advantageously employed for grinding
coffee, pepper, spices, bones, and plaster, and for grinding generally.
Having now described the nature of the said Invention, and the manner of
carrying the same into effect, I wish it to be understood that I do not limit
myself to the precise details herein described and illustrated, as the same may
be varied without departing from the nature of the said Invention; but I claim
as the Invention,―
Firstly, making a grinding mill of a series of nearly flat plates of iron or
other sufficiently hard metal or alloy, the surfaces of the said plates being
corrugated, grooved, or otherwise roughened, some of the said plates being
stationary, and others of the said plates moveable, the said moveable plates
alternating with the stationary ones, the said moveable plates being actuated
by a crank, as herein-before described, and illustrated in the accompanying
Drawing.
Secondly, making the upper edges of the plates thinner than the lower
edges in those parts constituting the bottoms of the grooves, the thickness of
the said plates gradually increasing from the top to the bottom, or making
the grooves or depressions between the ribs on the said plates shallow at the
bottom, and gradually deeper as the said grooves or depressions approach the
tops of the plates, as herein described and illustrated in the accompanying
.Drawing.
Lastly, notching the plates on their upper edges to facilitate the breaking
and feeding of the substance to be ground, as herein-before described and
illustrated in Figure 5 of the accompanying Drawing.
In witness whereof, I, the said Thomas Averill, have hereunto set
my hand and seal, this Fourteenth day of February, in the year of
our Lord One-thousand eight hundred and fifty-nine.
Witness,
GEORGE SHAW.
THOMAS AVERILL. (L.S.)