IMPROVEMENTS IN MACHINERY FOR PULVERIZING OR MIXING MINERAL AND VEGETABLE SUBSTANCES
Year: 1871

page_text: LETTERS PATENT to William Prosser, of 9, Corporation Street,
Manchester, in the County of Lancaster, Merchant, for the
Invention of " IMPROVEMENTS IN MACHINERY FOR PULVERIZING OR MIXING
MINERAL AND VEGETABLE SUBSTANCES."
Sealed the 23rd February 1872, and dated the 26th August 1871.
PROVISIONAL SPECIFICATION left by the said William Prosser at the
Office of the Commissioners of Patents, with his Petition, on the
26th August 1871.
I, WILLIAM PROSSER, of 9, Corporation Street, Manchester, in the
3 County of Lancaster, Merchant, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN MACHINERY FOR PULVERIZING OR
MIXING MINERAL AND VEGETABLE SUBSTANCES," to be as follows :—
I force the substance to be disintegrated by means of a blast of air
passing at greater or less velocity through a tube or tubes against the

page_text: bars of a revolving cage. The necessary force may be imparted to
current or currents of air by means of an air blowing machine, or by
means of an air blowing machine and a strong vessel or vessels made of
iron or other material to serve as an air compressor or compressors, or
other suitable apparatus. That portion of the machinery against which
the substance is impinged by the blast consists of a strongly made iron
cage placed on a revolving axle or shaft. Passing from end to end of
this cage are bars made of iron, or other material, and placed at regular
intervals from each other, thus forming one or more concentric circles
of bars. The cage thus formed is made to revolve with a greater or less
degree of rapidity, according to the degree of fineness to which it is
requisite to disintegrate the substance, and according also to the degrec
of force imparted to the blast. If the necessary state of fineness is not
attained by using one cage and a certain force of blast, two or more
cages may be used, so placed that the particles after being partly
pulverized by one cage will be caught up by the revolving bars of the
second or other cages, till the substance be reduced to a sufficiently
fine condition.
In other disintegratory machines the whole of the force for impinging
the substance to be pulverized against the bars of the cages is generated
in the cages themselves, by causing them to revolve with extreme
velocity.
The high rate of speed necessary for disintegrating many substances,
such as wheat, occasions considerable difficulty in keeping the bearing
surfaces cool, or in working the machine for any length of time without
stopping. In my Invention however I generate most of the necessary
force for impinging the substance against the bars on the outside of the
cages, and thus obviate the necessity of driving them with such a high
degree of velocity, and also save much wear and tear of machinery, and
secure the possibility of runing continuously for any length of time.
I may use steam instead of air where heat or moisture cannot injure
the substance to be pulverized.
I also employ the combination of a blast of steam or air, together
with a system of cages working in opposite directions, and formed as
follows:-I make a strong cage of iron or other material, having bars
of iron or other material placed around the edge and with open spaces
between them, and if necessary, I place several series of such bars

page_text: '
concentrically with the axle upon which the cage revolves; and these
series of bars are placed sufficiently far apart from each other to admit
of the insertion of similar series belonging to a cage made precisely in
the same manner. These two cages are then made to revolve by means
of pulleys or other geering in opposite directions. The ends of the cages
are made in the following manner :-One end is closed and the other
end is open; when therefore it is desired to pulverize any substance it is
introduced into the central opening; it is then impinged by the first
series of bars or beaters, and is then thrown by centrifugal force and is
( met by the first series of bars of the next cage, which revolving in the
opposite direction meets it with increased force, and thus the particle is
thrown from beater to beater till it comes out at the circumference
pulverized. The force with which the particles are driven against the
beaters depends however on two conditions, namely, the force with
which it is blown by the blast, whether it be steam or air, and the
speed with which the cages are made to revolve. In this, as in the last
case, much of the force requisite for the pulverization of materials is
generated on the outside of the cages in the form of a blast of air or
steam, and as in the other case the cages need not revolve with nearly
as great a velocity, consequently there is very much less wear and tear
of machinery.