IMPROVEMENTS IN AND APPLICABLE TO MACHINERY OR APPARATUS FOR GRINDING OR REDUCING GRITS, GRAIN, AND OTHER LIKE SUBSTANCES
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the Office
of the Commissioners of Patents on the 13th January 1880. A communi-
cation from abroad by Auguste Frédéric Beyer and Adolphe Gustave Beyer,
both of Paris, in the Republic of France, Engineers.
A
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN AND APPLICABLE TO MACHINERY OR APPARATUS
FOR GRINDING OR REDUCING GRITS, GRAIN, AND OTHER LIKE SUBSTANCES."
communication from abroad by Auguste Frédéric Beyer and Adolphe Gustave Beyer,
both of Paris, in the Republic of France, Engineers.
This Invention relates to improvements applicable to mills constructed with
porcelain cylinders employed for grinding grits and other similar produce in a
granular condition, grain and the like. These improvements consist more particularly
in arrangements by means of which the substance to be ground is supplied to the
cylinders with mathematical regularity and in the greatest possible quantity which
the said cylinders are capable of treating. This result is obtained by introducing
the substance to be ground into a hopper of wood or of metal enamelled on the
interior, and presenting a rectangular opening of considerable area in which the
substances are spread in a thin layer upon one or the other of the cylinders,
preferably upon the cylinder which rotates with less speed than the other, after
which the substance is distributed between the two cylinders by means of a long
hollow or solid semi-circular feeder carried on an axis situate above one of the
cylinders, and capable of being adjusted in its proper position by means of a
worm wheel and endless screw.
On leaving the cylinders the ground substance is acted on by a rotating brush
which effects a supplementary disintegration or separation of all the particles of
the substance which may still adhere together after passing between the cylinders.
In carrying out this Invention the procelain cylinders are enclosed in a case of
wood having a rectangular opening in the upper side, and the edges of this opening
are provided internally with depending ledges forming a hopper, the lower edges
of which are carefully fitted so as to come as nearly as possible in contact with
one of the cylinders without actually touching it. This hopper is preferably
constructed of metal enamelled on the interior if required, and is provided with a
feeder or valve serving to collect hard impurities or foreign bodies which are
sometimes present in the substance to be ground, and which might otherwise injure
the porcelain cylinders.
Another hopper of wood may be provided above the one described, being
supplied by a shoot.
The valve or feeder is capable of turning freely upon an axis passing through
the sides of the hopper and through lugs on the frame work of the mill, and is

page_text: provided at the middle of its length with a toothed segment engaging with a screw
actuated by a handle or knob outside the hopper, by means of which its position
may be altered and adjusted with precision for the purpose of regulating the feed.
The feeder or valve may be solid or hollow and is of a semi cylindrical form,
being so arranged as to present its flat side to the interior of the hopper. A comb
or rake is provided on this side of the feeder formed of a flat plate of metal
having teeth on its lower edge which come in contact with the periphery of one of
the porcelain cylinder, and serve to prevent the passage of foreign bodies between
the said cylinders. The teeth may be either straight or curved or bent at right
angles to the flat plate on which they are formed," and the upper edge of said
plate may be bent forward at right angles to the plate, or the upper edge of the
plate may be bent round so as to form an oval eye, by means of which it is
suspended on the axis of the feeder.
Reciprocating motion in the direction of its length is imparted to the rake, as
hereinafter described.
The motion of the comb or rake may be imparted to it by the feeder, which has
a reciprocating movement for the purpose of adjusting the feed according to the
quantity of the substance to be ground which it is desired to supply to the cylinders.
This sifting comb or rake may be arranged to lie flat against the feeder or its
functions may be performed by the feeder itself by means of a stop of undulating
form provided in the passage. All these parts may be readily taken apart by with-
drawing the axis of the feed roller.
The feeder may also be made in the form of a segment of less extent than a semi-
cylinder.
Vanes or blades or a sliding valve forming a continuation of the side of the hopper
and adjustable by means of a screw may be employed in lieu of the semi cylindrical
valve herein before described.
The rake and feeder may be employed in combination with mills constructed
according to the Invention for which Letters Patent were granted to John Henry
Johnson, dated the 16th October 1877, No. 3824, with one or more pairs of
cylinders and also with cylinders coupled together end to end on the same axis and
shrunk on according to the same Invention. The ends of the cylinders in the latter
case are separated by means of a washer soldered to the shaft.
Mills of this description are provided with self lubricating bearings of cast iron
of great length carefully fitted and ground.
One of these bearings carries an eccentric ring and pivotted rod or device for
imparting reciprocating motion to the feeder, which ring rotates at a different speed,
motion being imparted to it by means of an intermediate cone carried on an arm
capable of adjustment for regulating the tension of the belt.
In order to obtain the requisite pressure at the point of contact between the pairs
of cylinders when two pairs are employed a single spring in one length is provided
for both pairs of cylinders having a tightening screw in the middle and an adjusting
screw near each end, or two separate springs may be employed of equal strength and
each provided at the centre with a tightening screw.
The particles of meal which still adhere together after passing between the
cylinders are completely separated and disintegrated by means of a rotating brush
composed of a rotating disc mounted upon a long shaft and provided with small
brushes which rub against a stationary disc provided with projections.
The relative position of the two discs inay be adjusted by means of a screw, and
motion is imparted to the brush by a belt from the driving pulley of the mill or by
means of toothed gearing or by the axis carrying the intermediate cone.