IMPROVEMENTS IN MILLS FOR HULLING MAIZE
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the
Office of the Commissioners of Patents, with his Petition, on the
8th December 1873.-A communication from abroad by Valentine
Winters, of Dayton, Montgomery County, State of Ohio, Robert
McGregor, Alexander McGregor, and Robert Henry Minister, of
Baltimore, Baltimore County, State of Maryland, both in the United.
States of America.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN MILLS FOR HULLING MAIZE," to be as
follows:-
This Invention relates to an arrangement of parts in a "hominy'
mill, which ensures an equal and uniform conversion of all the corn into
"hominy" of good merchantable quality.
On a base or foot rise posts supporting a fan case, which itself supports
a discharge chamber. Both the fan case and the discharging chamber
empty into a spout having a descending ventage for the "hominy," and
an ascending ventage for that portion of the dust which has been drawn

page_text: down the interior of a central hollow perforated shaft by the suction,
and down the central apertures of a series of annular floors or diaphragms,
each of which is formed of two halves cast from a common semicircular
pattern. The said diaphragms are precisely alike and symmetrical on
both sides, and each floor the exact duplicate or copy of every other.
Each floor has a central circular aperture having marginal rims or lips
above and below. Circular grooves immediately within the outer margins
of the floors on their upper sides, and precisely similar grooves on their
lower sides receive and hold the edges of a series of peculiarly formed
cylindrical or ring-shaped screens, which with the diaphragms as above
constitute the main portion of the case.
Each of said screens is cast in a single piece from a common or single
pattern, and is transversed by a series of slits or narrow perforations
which flare from within outward, and which commencing near the top
of the screen pass outward through the bottom edge thereof. The screen
thus formed is easily cast in one entire ring or cylinder, which in the
described combination with the diaphragms, et cetera, compose a very
staunch and compact case, which is free from the open joints and
insecurity incident to cases with longitudinal joints..
An aperture is provided in the cap or cover of the mill to receive
grain from any suitable shoe or hopper, and to conduct it into a funnel
whose central aperture leads into the uppermost hulling compartment.
The hollow perforated shaft before mentioned is provided with nibbed
blades or triturators, and numerous minute apertures. The interior of
the shaft communicates at bottom with the centre of the fan case.
The shaft flares externally downwards, so as to cause the apertures
between the diaphragms and the shaft to decrease in area towards the
lower part of the mill.
(:
The fan shaft is rotated by a pulley at about one thousand revolutions
per
minute. Said shaft also carries a wing for discharging the "hominy"
into the spout.
The shaft rests in a step, which is adjustable vertically by means of a
handle and inclined planes, so as to enable the simultaneous expansion
or contraction of the entire series of annular passages between the shaft
and the internal margins of the diaphragms.

page_text: The step is held at any desired adjustment by a set screw, or in place
of the above the step may be adjusted by a set screw or lever bearing
directly upward against it.
All the above parts are confined securely together by a series of
rods.
The operation is as follows:-The mill being set in motion corn is fed
in through the hopper, and descending into the upper compartment its
kernels are driven violently against the vertically slotted screen by the
action of the nibbed blades, until the compartment becomes charged
with grain, after which the incoming portions act to press the lower
strata of grain toward the annular passage between the diaphragm and
the shaft. In the act of approaching the margin of the passage the
grains are arrested by the lips, and being caught by one of the blades
are projected again toward the circumference. This action operates to
retain the corn in the mill until each and every compartment becomes
fully charged with grain, after which the entire volume moves steadily
downward by a helical motion to the place of discharge. From and
after the complete charging of the compartments the combined action
of the blades and suction is not to strike the individual kernels so much
as it is to rub and triturate them forcibly against each other, and against
the screens and diaphragms, resulting in a very thorough hulling action
without breaking or destruction of the kernels.
The diaphragms are most effective with their original rough cast
surfaces, and as the wear is most severe on their upper surfaces, and
greatest on the upper diaphragms, the symmetrical and two-parted form
of the diaphragms become available for transposition and reversal of the
diaphragms, so as to make the comparatively uniform surfaces take the
place of those which have been scoured smooth. The diminution down-
ward of the series of annular passages in the diaphragms as they approach
the place of discharge is made just sufficient to counteract the disposition
of the contents to escape more freely as they become more comminuted
and approach nearer to the suction.
The vertical apertures in the screen act in conjunction with the
centrefugal force created by the revolving shaft and blades to carry off
sand and other heavy refuse, while the lighter particles of dust and

page_text: powder are drawn by the suction down the interior of the shaft and
down the annular passages, and are blown out at the spout.
The screens are preferably made with their slits opening downward,
although they may be arranged either upward or downward, as may be
desired.