IMPROVEMENTS IN SUCTION OR FILTERING APPARATUS USED IN CONNECTION WITH FLOUR MILLS OR THE LIKE
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Frank Wirth at the Office of the
Cominissioners of Patents on the 10th November 1881. A communication
from Gerhard Baier, of Ulm, in the Empire of Germany.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort on the Main, in the Empire of Germany.
"IMPROVEMENTS IN SUCTION
OR FILTERING APPARATUS USED IN CONNECTION WITH FLOUR MILLS OR THE
LIKE." [A communication from Gerhard Baier, of Ulm, in the Empire of
Germany.]
According to this Invention I provide a double filtering and self acting aspirating
apparatus, chiefly designed to be connected with mill stones by an automatic
disconnecting arrangement, by means of which the dust filter is cleansed of dust
at definite times through an excentric shoking motion. I provide a self acting
throttle valve with its orifice outward, through which, during the cleansing process,
fresh air is introduced into the vacuum in the dust filter, and works in such a
manner that the aspired current of air is stopped before the filter is set in motion,
and brought on again only after a measured time.
first one.
In carrying the said Invention into practice I provide a case made entirely of
iron which rests upon a stone or brick frame. Inside the case there is a wire
basket within an inner dust filter, this basket being fastened to a vertical rod
which is pressed down by a spiral spring. There is also another filter outside the
In order to conduct the air much mixed with flour particles free from
dust through a tube leading into the apparatus, air has to make its way
through two wool filters, by which the very smallest particle of flour is retained.
Through this retention and the deposit of dust on the filter a conting of flour is
gradually formed, which would render a further passage of the air impossible, were
not the cleansing of the filter to take place at certain definite intervals. But as
this cleansing can properly take place by means of a continuous or by means of a
sudden current, a valve is brought into action which opens outwardly the moment
the inner tube is closed, and allows fresh air to enter the vacuum in the dust filter.
This takes place by means of a throttle valve provided with an outwardly turning
part, which accomplishes by means of a lever provided with wool and a bar the

page_text: closing and opening of the valve in such a manner that the first takes place
3 seconds before, and the latter 20 seconds after, the motion of the dust filter has
taken place. A weight is provided to cause the automatic action of the turning slide
and of the valve. The filtering portion of the apparatus is connected with two
pulley blocks, one of which is concentric and the other excentric, and these cause
the filter to be lifted and to fall. Fast and loose pulleys are arrayed on a shaft,
and as soon as the driving belt is shifted from the loose pulley to the fast pulley
the connection is established. Through the turning of the bar the tube is opened
outwardly and the valve inside the same is closed, the axle of the excentric pulley
is turned and causes the dust filter in the case to receive a vertical shaking motion.
The shifting of the driving band is performed by a disconnecting apparatus in
a regular manner every 15 minutes. A driving pulley sets a worm in motion,
which at every turn moves a wheel one tooth forward. There is another toothed
wheel, and the motion of the two toothed wheels is as one to ten, that is to say,
whilst the second one turns once around its axis the first one revolves ten times.
There are two cams provided with suitable notches. At one tenth revolution of
the cam in connection with the first toothed wheel, the cam in connection with the
second wheel has turned once, the notches of both cams meet at that moment, and
a rod pressed by a spring and having two friction rollers glides on the notches;
this operation shifts the belt forward, and thus shuts off the inner current in the
tube, opens the aperture of the same to the air from outside, turns the excentric
pulley, and agitates the dust filter. As soon_as_the_friction-roller-in-connection
-with-the first cam is drawn onto the outer circle, the valve springs. back through
the action of the self acting weight, the parts are replaced, and the whole remains
again at rest for 15 minutes.