IMPROVEMENTS IN THE MACHINERY AND APPARATUS FOR GRINDING CORN
Year: 1855

page_text: LETTERS PATENT to Joseph Hull, of Liverpool, in the County of Lancaster,
for the Invention, of "IMPROVEMENTS IN THE MACHINERY AND APPARATUS
FOR GRINDING CORN."
Sealed the 5th October 1855, and dated the 7th April 1855.
PROVISIONAL SPECIFICATION left by the said Joseph Hull at the Office
of the Commissioners of Patents, with his Petition, on the 7th April
1855.
I, JOSEPH HULL, of Liverpool, in the County of Lancaster, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN THE MACHINERY &
APPARATUS FOR GRINDING CORN" to be as follows, viz. :-
I work certain peculiarly formed furrows in the face of the stone, which
enables me to work at a much higher speed than heretofore, inasmuch as the
stones at present in use usually revolve at 100 to 130 times per minute, any
higher speed being found highly injurious. I am enabled by my Invention
to work at a speed of about 200 revolutions, & producing a proportionate
increase of work thereby.
The novelty in the working of the furrows consists in carrying the furrows
through the main land into the main furrow, and giving the stone 1₁ in. of
leed to the foot. On the diameter of the stone, a worm is made on each side
of the eye, and an exhaust fan of novel construction acts as an auxiliary in
drawing the air from the casing of the stone.
casing of the stone. I am thus enabled to grind
about double the quantity of corn per hour with but little additional power.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Joseph Hull in the Great Seal Patent Office on the 6th
October 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
HULL, of Liverpool, in the County of Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of April, in the year of our Lord One
thousand eight hundred and fifty-five, in the eighteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Joseph Hull, Her special licence that I, the said Joseph Hull, my executors,
administrators, and assigns, or such others as I, the said Joseph Hull, 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 "IMPROVEMENTS IN THE MACHINERY AND APPARATUS
FOR GRINDING CORN," upon the condition (amongst others) that I, the said
Joseph Hull, by an instrument in writing under my hand and seal, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Joseph Hull, do hereby declare the
nature of my 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 and accompanying Drawings (that is to say) :-
My Invention relates to a novel mode of setting out and working the furrows
in the grinding faces of mill stones, by which means I can produce a larger
quantity of flour in a given time with the same amount of power as at present
employed.
The second part of my Invention relates to exhausting the heated air from
around and between the stones so worked, by means of a suitable fan or
exhauster, and so keeping the grinding stones and the materials between
them cool, instead of forcing cold air from the fan blast into the eye of the
running stone.
In illustration of my Invention, I have hereunto annexed a Drawing, in
which Fig. 1 exhibits the face of a stone worked with those furrows with a lead

page_text: or angle set out with these furrows according to my Invention, where there are
twelve sets of three furrows marked upon the face.
Fig. 2 is a general view of the arrangement, shewing a section of the top
stone, the case under which it is placed,, and a form of fan for exhausting,
together with the trunk and air connections between the case of the stones and
the hot air chamber. Fig. 3 is an end view of the exhaust fan and case shewn
in Fig. 2, and the trunkings, &c.
I claim as forming the first part of my Invention, 1st, carrying the furrows
through the main land into the main furrow, when there is more than one
furrow in a set; 2nd, setting out the furrows and working the stones with
a "lead" or divergence from the centre of the stone of not less than three
quarters of an inch on each foot of the diameter of the stone, nor exceeding
one inch and one quarter of an inch on each foot of the diameter of the stone;
3rd, working an inclined and tangental groove or "worm." on two opposite
sides of the eye of the stone to ensure the fair feeding of the corn to stones
prepared or worked according to my Invention only..
The second part of my Invention relates, 1st, to the use of an exhauster or
fan in combination with stones worked according to the first part of my Inven-
tion, whatever the kind or form of such exhauster may be; 2ndly, the driving
of the heated air, the fine dust, and deteriorated flour from the exhausting
apparatus into a suitable chamber where the solid particles of flour and dust
may be separated.
Having stated the nature of my claims in respect of my Invention, I wish it
to be understood that, although I have shewn in the Drawing hereunto annexed
twelve sets with three furrows in each set, I do not confine myself -to tho
number of furrows in a set, nor to the number of sets in a stone when the lead
or divergence from the centre exceeds three quarters of an inch, and does not
exceed one inch and one quarter of an inch to each foot in the diameter of the
stone; but have found by practice that for the average run of stones, the "lead"
should be nineteen-sixteenths of an inch (one three-sixteenths) to each foot in
diameter. Neither do I confine myself to driving the top stone; but. claim
for my Invention its application, whether the top or the bottom stone revolves,
or if both stones revolve.
As fans have already been used in various ways, I do not make any claim
to the use of a fan, or other such contrivance, except as already described
and set forth, for exhausting from the case surrounding the stones worked
according to the method described by me as the first part of my Invention.
Fig. 1 is a plan of the face of a grinding stone worked with twelve sets,
each with three furrows; the land being black, the furrows white, by way of

page_text: distinction, and is intended rather to convey distinctly the mode of working the
stone in the manner described, and shewing the manner in which the furrows
are carried into the main land, than as exhibiting the amount of lead per foot,
to a correct scale. I have dotted in red ink lines, shewing the main land into
which the furrows numbered 1, 2, 3, run. The toggle and lugs for driving
the stone are omitted from the eye of the stone. The two worms b, b, are
shewn as directing the feed into the furrows of the several sets.
In Fig. 2, the general arrangement of the top stone and the surrounding
case is shewn. The fan is also shewn as worked in the room above, and con-
nected with the casing of the stones by a trunk or pipe; the arrows shew the
direction of the current. The heated air and the matters with which it is
charged being exhausted by the fan from the stones and the casing, cold air
rushes in through the opening e into the eye of the stone d, to supply its place.
By placing a flanged collar of leather around the inlet tube of case, so that
the flange works upon an iron ring or circular plate let in round the eye
of the stone on its upper end, a good air-tight joint is made thereby whilst
the stone revolves. The chamber into which the heated air and materials
exhausted from the stones when at work are driven into, may be composed
of canvas or of fine wire-work pancls, for the sides and roof, or if an ordinary
room be used, it must be ventilated so as to freely permit the air to escape as
it is driven in, care being taken to separate the solid particles therefrom.
Fig. 3 is an end view of the fan shewn in Fig. 2; the two pipes g, g, con-
nnecting the main trunk i with the centre of the fan, and the short pipe or
trunk piece k, by which the main trunk is connected to the case m, is shewn
as broken off.
In witness whereof, I, the said Joseph Hull, have hereunto set my
hand and seal, this Third day of October, in the year of our Lord One
thousand eight hundred and fifty-five.
Witness,
WILLIAM SMITH, C.E.,
10, Salisbury St., Adelphi.
JOSEPH HULL. (L.S.)