IMPROVEMENTS IN THE CONSTRUCTION OF APPARATUS FOR GRINDING GRAIN AND OTHER SUBSTANCES
Year: 1851

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
SHEPPARD, of Strickton Iron Works, Fordingbridge, in the County of Hants,
Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Thirteenth day of November, in the fifteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said.
George Sheppard, Her especial license, full power, sole privilege, and authority,
that I, the said George Sheppard, my exors, adñiors, and assigns, and such others
as I, the said George Sheppard, my exors, admors, or assigns, should at any time
agree with, and no others, from time to time and at all times during the term
of years therein mentioned, should and lawfully might make, use, exercise,
and vend, within England, Wales, and the Town of Berwick-upon-Tweed, my
Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF APPARATUS FOR GRINDING
GRAIN AND OTHER SUBSTANCES;" in which said Letters Patent is contained
a proviso, obliging me, the said George Sheppard, by an instrument in writing"
under my hand and seal, particularly to describe and ascertain the nature of
my said Invention, and in what manner the same is to be performed, and to
cause the same to be inrolled in Her Majesty's High Court of Chancery
within six calendar months next and immediately after the date of the said in

page_text: part recited Letters Patent, as in and by the same, reference being thereunto
had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
George Sheppard, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, is particularly described and
ascertained in and by the following description thereof, reference being had to
the Drawings hereunto annexed, and to the letters and figures marked thereon
(that is to say) :-
:-
This Invention refers, firstly, to the separation of the air which during the
operation of grinding is drawn between the millstones from the meal or other
pulverized material as it is delivered from the grinding surfaces, the object
being to prevent the waste and other inconveniences which have hitherto been
occasioned by passing the flour and air out from the case surrounding the mill-
stones at the same vent into a receiving chamber, whence the air was allowed
to escape. To attain this end, I propose to enclose the stones in an air-tight
case, having two outlets, pipes, or passages, one at top for the escape of the air,
and the other at bottom for the escape of the meal or other pulverized material,
and when operating with two or more pairs of stones, I connect the air outlet
pipe of each case with a main air trunk, which leads to the case of an exhaust
fan, and by this means I am enabled to draw off the air simultaneously from
the cases of all the stones that are in operation. The grain or other material
to be ground is fed through the eye of the top stone or runner, and the peri-
phery of this stone is provided with sweeps of a peculiar form for sweeping
the meal as it exudes from between the grinding surfaces down the shute into
a receiver, and at the same time retards or prevents the meal from flying
upwards and escaping from the case with the exhaust air.
In the accompanying Drawing, forming part of this my Specification, Fig. 1
represents two pairs of stones fitted up according to this Invention, one pair
being in side elevation, and the other pair in vertical section; and Fig. 2 is a
plan of one of these pairs of stones. A is the bed stone; B, the runner con-
nected by means of a central cross bearing C to a driving spindle D. Within
the eye of the runner is a flanged ring a, which carries a tube b; forming the
inner periphery of the annular casing E. This casing encloses the runner, and
is rendered air-tight, or nearly. so, by fitting tightly round the bed stone; Fis
a pipe leading from the case E to the main air trunk G, which is in connection
with the fan or blower H, and is intended to form a channel of communication.
between this exhaust apparatus and the several pairs of stones contained in the
mill; I, I, are the sweeps affixed to the periphery of the runner, and intended

page_text: to push forward the meal as it passes out from between the grinding surfaces,
and deliver it into the descending spout or shute K, which guides it into a
proper receiver. The form of these sweeps is best shewn in the detached view,
Fig. 3, which represents one of the sweeps in edge view. It is bent over as
shewn, for the purpose of intercepting (as the stone is rotating in the direction
of the arrow, Fig. 3,) any particles of meal that may be following the course
of the air, and thereby preventing their escape at the pipe F. The several
pipes which establish a connection between their respective cases E and the
main air trunk G, should be provided with valves, in order to cut off that con-
nection when any one of the pairs of stones are not in work, and each shute K
should be provided with a valve to prevent the possibility of the return of the
meal into the case E by the too violent action of the exhaust fan.
The operation of the apparatus is as follows:-The fan I having been set
in motion, and grain or other substance to be operated upon being fed into the
mill, a current of air passes down the eye of the runner with the grain,
traverses between the grinding surfaces (keeping them cool and assisting the
grinding action), and eventually escaping up the pipe F and air trunk G,
makes its escape into a chamber, and thence to the atmosphere, or to the
atmosphere direct. The grain in the meanwhile having been reduced to
meal, is delivered on to the bottom of the case E, is gathered up by the
sweeps I, and discharged from the case E down the shute K. In order to
ensure the perfect separation of the meal from the air, a silk, canvas, or wire
cloth diaphragm is fitted within the case E, as shewn at L, L, whereby any
particles that may pass the sweeps I will be effectually prevented from
escaping with the air up the pipe F.
The second part of this Invention refers to the construction of the mill-
stones, the object being to produce stronger and more durable stones, and
possessing a better grinding surface than those at present in use.
This part
of the Invention is shown at Fig. 4. The stone is composed of taper burrhs
a, a, a, of such a form, that when set radially they will produce the form of
stone required. These burrhs are bound together by iron bands, which being
passed round their periphery hold them firmly in their place.
Having now described my Invention of "Improvements in the Construction
of Apparatus for Grinding Grain and other Substances," I wish it to be
understood, that under the above in part recited Letters Patent I claim,—
First, the means herein-before described, whereby I am enabled to separate
the air which is drawn in between the grinding surfaces (for ventilating the
stones or keeping them cool) from the meal or other manufactured product,

page_text: and to deliver such product into a suitable receiver without the waste or
inconvenience heretofore resulting from the use of a current of air for
ventilating the grinding surfaces.
And, secondly, I claim the constructing of millstones as above described.
In witness whereof, I, the said George Sheppard, have hereunto set my
hand and seal, this Tenth day of May, in the year of our Lord One
thousand eight hundred and fifty-two.