IMPROVEMENTS IN APPARATUS EMPLOYED IN GRINDING CORN AND OTHER SUBSTANCES CAPABLE OF BEING GROUND BY MILLSTONES
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by Edward Alfred Cowper at the
Office of the Commissioners of Patents, with his Petition, on the 5th
December 1865.
I, EDWARD ALFRED COWPER, of No. 354, Great George Street, Westminster.
in the County of Middlesex, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN APPARATUS EMPLOYED IN GRINDING CORN AND OTHER
SUBSTANCES CAPABLE OF BEING GROUND BY MILLSTONES," to be as follows:-
It is now well known that in grinding corn and other substances there is
considerable advantage obtained by using an exhausting apparatus to partially
exhaust the air from the casing of the millstones, so as to cause more air to
pass in between the grinding surfaces with the material being ground, such
information having been fully published by the Specification of a Patent
granted to Alfred Vincent Newton, dated 11th February 1846, No. 11,084,
It is ordinarily found that in exhausting the casing of the millstones for this
purpose a current of air passes up the spout down which the flour is falling
and carries away with it some portion of the finer particles of the meal or
flour, and thus the degree of exhaustion which can be usefully employed is
very limited. Several endeavours have been made to obviate this injurious
effect by placing valves in the spout, which are kept closed by the pressure of
the atmosphere acting on their outsides, and which only open when a sufficient
quantity of meal has accumulated in the spout to force the valves open by-
its weight; such arrangements are open to the serious objection that the
meal is very liable to choke up the spout altogether, and cause the stones to

page_text: "
"clam" or paste up." Now by my Invention I keep the spout continually
closed, so as to prevent the admission of air, whilst I allow the meal to pass
freely out, whereby the before-mentioned evils resulting from a considerable
exhaust are entirely avoided.
My Invention may be put in practice in a variety of ways; thus, in ono
arrangement, I place at the bottom of the meal spout a small wheel having
blades on its circumference (very like a small water wheel), partially enclosed
in a case nearly fitting the same, communicating at the top with the spout,
and having an opening at the bottom for the exit of the meal. This wheel is
caused to revolve so as to allow the meal to pass freely by falling into the
buckets at top and falling out of them at bottom. Instead of employing only
one such wheel, two wheels may be employed working close to each other.
Or a series of buckets fixed upon an endless belt or chain, similar to a chain
pump or Jacob's ladder, may in like manner be arranged to work in a close
casing communicating at top with the meal spout and open at bottom for the
exit of the meal.
In another arrangement a hollow cylinder, constituting a bucket by having
an aperture in one part of its circumference, is made to revolve inside a closely
fitting casing communicating at top with the meal spout and open at bottom,
so that as the aperture in the cylinder passes the opening into the meal spout
it receives a portion of meal, which immediately falls out as the aperture
passes the bottom opening.
In another arrangement two throttle valves are placed a certain distance
apart in a vertical meal spout, and are caused to rotate, so that when one is
open the other is shut, and vice versa. Or in place of making the valves
revolve in the spout, I cause them to slide backwards and forwards across the
spout in a similar manner to the valves in a shot belt, care being, however,
taken that one valve is closed before the other opens. Or in place of
employing valves I make the meal spout of a flexible material, and alternately
close it at two or more points by pressing it together from the outside.
Although my Invention is more particularly applicable to the grinding of
corn, yet it may also be applied with advantage to the grinding of other
substances capable of being ground by millstones, such as, amongst others,
seeds, drugs, paints, coprolites, cements, steamed bones.