Improvements in Grinding Mills for Pulverizing Materials.
Year: 1891

page_text: Date of Application, 7th Mar., 1891
Complete Specification Left. 7th Dec., 1891-Accepted. 9th Jan.. 1892
PROVISIONAL SPECIFICATION.
Improvements in Grinding Mills for Pulverizing Materials.
I, ROBERT ARTHUR NORMAN of Cricket Road, Sheffield, in the County of
York, Engineer, do hereby declare the nature of my invention to be as follows:-
This invention is for improvements in the construction of mills for grinding,
granulating, or pulverizing various materials.
It consists of a disc or grinding wheel, (the periphery being the grinding face)
fixed upon a horizontal driving shaft and revolving with it. The periphery of the
disc or wheel is made with a central ridge, each inclined side or face being cut or
serrated as desired, such serrations are preferably deep at the edges of the disc,
and run out towards the ridge.
The outer grinding face is semicircular or thereabouts, thus enclosing about half
the periphery of the disc or wheel, and that half being the descending one, when
revolving.
The space, intermediate between the disc and the outer face, is greater at
the top or inlet, than at the bottom or outlet, and this can be adjusted by suitable
means.
The unground material is intended to be fed between the two grinding faces, by
means of a hopper and shoot in the usual manner, and received at the outlet, which
is at the bottom of the machine.
Brushes or scrapers may be applied to the opposite or rising side of the disc to
keep it clean, and the parts are enclosed in a suitable casing, or outer shell, through
which the shaft or axle projects, and is supported in bearings rising from the base
plate.
Double, or compound mills may be constructed upon my improved method.
ROBT. F. DRURY, Fel. Inst. P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.
COMPLETE SPECIFICATION.
Improvements in Grinding Mills for Pulverizing Materials.
I, ROBERT ARTHUR NORMAN of Cricket Road, Sheffield in the County of
York, Engineer do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
This invention is for improvements in the construction of mills for grinding,
granulating, or pulverizing various kinds of materials such as Indian corn for
example, and is illustrated in the annexed sheet of drawings, in which,
Fig. 1, is a side elevation of a mill constructed according to my invention the
casing being partly in section to show the interior.
Fig. 2, diagram showing arrangement for a double-runner mill.
Fig. 3, sections showing various forms of grinding faces that may be used.
A single-runner mill consists of an outer casing A, secured upon a strong base B,
with standards or pedestals to support the driving shaft or axle C, of the runner,
disc, or grinder D, which is securely fixed upon the shaft, as well as the pulley or
pullies and usually a flywheel, but other means of driving the mill may be used.
There is also shoe or stationary grinding block E, with means for adjustment and
a hopper.
The runner or grinder D, as before stated, is secured upon the axle C, and

page_text: therefore revolves with it, and it may be made either solid that is in one piece of
metal, or it may be made with a removable periphery so that that portion alone
would require renewing when worn out. The face of the periphery of the runner
or disc may be of any desired form either flat, rounded, wedge-shaped or of similar
forms as may be found to give the best result upon different materials and may be
plain or provided with any number of serrations or grooves, either of equal size
or varying in that respect.
I may make the runner of steel, chilled cast iron, or of other metal or combina-
tion of metals.
The shoe or stationary grinding block E, is preferably a chilled casting, but this
also may be made of ordinary cast iron having a removable steel grinding face as
indicated in the drawing Fig. 1.
It is of the same width or thereabouts as the runner and fits sideways into the
interior of the casing on the downward running side of the revolving grinder or
runner D, its back E', bearing either against the casing, or against a wood
backing F, interposed between the block and the casing for the purpose of deadening
the sound.
The grinding face of the shoe or block is of a segmental form, enclosing about
one quarter (which may be increased to nearly one half) of the periphery of the
runner.
The intermediate space between the face of the shoe and that of the runner
diminishes from the top to the bottom, and the distance between the two grinding
faces can be adjusted by raising or lowering the shoe E, which may be readily done
by means of a wedge-shaped slide block G, placed underneath it, and moved in
either direction by a screw H, turned by the hand wheel I.
The material to be ground is fed into the mill through a hopper J, from which
it drops between the grinding faces of the runner and shoe. K, is a scraper
to keep the runner clean, and L, is the outlet, for the ground material to drop
through.
A double mill may be constructed with two runners fixed upon the same axle
or shaft, and a casing formed with two compartments, or I may use the construction
shown in the diagram Fig. 2, the runners being on separate shafts, and the shoes E,
being placed as shown; the adjusting wedges G, may have separate screws H,
or they may be operated simultaneously by a screw having right and left hand
threads.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same may be carried into effect, I declare that
what I claim is :-
1. In a grinding or pulverizing mill the combination with a circular runner or
grinder D, of a stationary grinding block E, encircling from one quarter to one
half or thereabouts of the periphery of the runner, and having the intervening
space between the grinding faces increasing in width from the lower part upwards,
such space being made adjustable, substantially as hereinbefore described, with
reference also to the drawings.
2.-A grinding mill, consisting of an outer casing A, erected upon a base B,
with one
or more inner compartments; a driving shaft carrying a runner or
grinding disc D; a concave faced grinding block E; adjusting wedge G, and
screw H; arranged substantially as herein before described and having reference to
the annexed drawings.
Dated the 2nd 1
T
1001
ROBT. F. DRURY, C.P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.