Horizontal Centrifugal Grinding Mill.
Year: 1889

page_text: Date of Application, 5th Jan., 1889
Complete Specification Left, 13th Aug., 1889-Accepted, 14th Sept., 1889
PROVISIONAL SPECIFICATION.
Horizontal Centrifugal Grinding Mill.
JOHN SNELL CHENHALL, Mechanical Engineer 7 Wolseley Road, Eastville, Bristol,
county of Gloucester JAMES WARNE CHENHALL Civil Engineer Richmond Villa,
Churston Devonshire do hereby declare the nature of this invention to be as
follows
An Ore and other material Grinding Mill the body of the Mill is made of three
parts, the upper and lower casings being concave, with a wearing ring in the centre
(which is made in section) bolted together, the three portions forming an annular
chamber within which three or more balls are made to revolve, these balls grinding
the material between themselves and the inner circumference of the centre ring,
referred to above.
The balls are made to revolve within the chamber by means of projecting arms, to
which are applied adjusting blocks of suitable material, for taking up the wear between
the arms, in which the balls are inclosed, and by which they are propelled.
These arms are attached to a driving shaft through the top caseing of the mill, to
which the propelling power is attached, by any mechanical gear or appliance,
A Mill constructed according to our invention is shewn by the annexed drawing.
Figures 1-2-3. Figure 1-an elevation.
2-longitudinal section.
3-sectional plan.
Figure 2 A being the concave cascing.
B movable ring.
C revolving balls.
D projecting arms.
E adjustable block in the propelling arms.
F driving shaft.
G driving pulley.
H centre discharge.
Having thus described the nature of our invention, and the manner of performing
the same, we would have it understood that we do not confine ourselves to the exact
details shewn and described, but we claim, first,
1st The combination of parts constituting a Grinding Mill.
2nd The removable annular horizontal grinding ring, which being in sections,
and bolted with and by the concave cascings (constituting the body of the mill)
makes them perfectly rigid, but still adjustable for all wear.
3rd The means of adjusting the wear in the propelling arms.
4th The vertical shaft (to which the arms are attached) being placed: entirely
outside the grinding part of the mill, reduces the wear to a minimum.
January 21st. 1889
JOHN SNELL CHENHALL.
JAMES WARNE CHENHALL.
JAMES WARNE CHENHALL.
COMPLETE SPECIFICATION.
Horizontal Centrifugal Grinding Mill.
We, JOHN SNELL CHENBALL, of No. 7, Wolseley Road, Eastville, Bristol,
Mechanical Engineer, and JAMES WARNE CHENHALL, formerly of Richmond Villa
Churston, Devonshire, now of Dart Villa, Totnes, Devonshire, Civil Engineer do
37

page_text: 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:
Our invention relates to the construction of Mills for crushing or grinding ore and
other materials.
The object of our invention is to simplify the construction and working of ore
crushing machines, and to provide means whereby the friction and consequent wear
and tear hitherto connected with such machines may be reduced to a minimum.
According to our invention the ore is ground or crushed by means of balls which
are made to rotate rapidly in an enclosed or partially enclosed chamber; these balts
by their rapid centrifugal motion operate with considerable force, the constant
succession of blows quickly reducing the ore or other material with which they come
in contact to the required degree of fineness.
Our mill consists principally of three parts; 1, the chamber; 2, the balls; and 3,
the driving shaft and propelling gear and is constructed in the following manner :-
1. The chamber is formed in three parts, the upper, lower, and central; each of
the upper and lower portions forms a concave ring, the central portion is a broad
horizontal ring-plate; flanges attached to the outer edges of the concave rings admit
of the lower and upper portions being bolted to the ring-plate, the whole forming an
annular chamber; the ring-plate, against which the whole force of the balls is
expended, is liable to more wear than any other part of the interior of the chamber,
we therefore construct it in sections, when desirable, so that as the plate becomes
the sections may be re-adjusted, and the inner circumference restored to its
original size; to facilitate this re-adjustment, we insert pieces of hard wood or other
suitable material between the joints of the sections, and we make the bolt-holes in
the ring plate of an elongated shape, so that as it becomes worn, the plate may be
quickly restored to its original shape."
worn,
2. The balls, preferably three in number, are made of a size and weight suitable to
the work to be performed, and also to the size of the chamber in which they are to
operate.
3. The driving shaft is placed vertically in a strong cylindrical bearing which is
fixed above the annular chamber; on the upper end of this shaft a pulley is fixed, and
the lower end of the shaft projects slightly through the bearing into the interior of
the chamber, to this lower end is fixed an attachment of depending arms, corre-
sponding to the number of balls employed, each of these arms is divided at its-
extremities, and. is so shaped that it may partially surround the ball and control its
rotation, but leaves it free to move up or down, or from the centre to the circumfer-
ence; so that each ball may operate freely on the material placed in the chamber: on
the ends of the arms which propel the balls we insert pieces of wood or other
material to receive the wear of the arms, these pieces of wood are easily inserted and
renewed when required, and are adjustable; on the other ends of the arms scrapers
are fixed, which keep the ore which is in the bed of the chamber in a constant state
of agitation, bringing all portions of ore quickly within the operation of the
rotating balls.
The mill being constructed as described, a hopper for containing the ore and sup-
plying it to the mill is fixed on the upper surface of the chamber, either on one side
or entirely surrounding it so as to feed the mill more evenly after the ore is ground
to its required fineness it is discharged either through a conical screen at the bottom
of the chamber, or through openings in the periphery at a convenient height above
the path of the balls, openings being left in the ring-plate for the purpose.
The construction of our mill will be more readily understood by reference to
the accompanying drawings, in which similar letters are used to indicate similar parts
in all the figures:
:-
Fig. 1 is a plan of the mill, showing the arrangement of the balls, driving arms
and blocks, and the distance pieces which are placed on the ring-plate; Fig. 2 is a

page_text: plan of the ring-plate made in sections with the wood blocks and the means employed
for adjusting the ring-plate when it has become worn; Fig. 3 is an elevation of the
mill with the hopper on one side, the channel for the discharge of the crushed ore
being through a conical screen placed in the centre of the mill; Fig. 4 is an elevation
showing the hopper round the top of the mill, openings being left in the periphery of
the chamber for discharging the ore; Fig. 5 is a section of the same, showing details
of the depending arms for driving the balls, and the periphery discharge; Fig. 6 is
a section of the mill as shown in fig. 3; and Fig. 7 is a section showing the means of
adjusting the blocks in the propelling arms. Figs. 1, 4, and 5.represent the mill as
constructed with the outlet for discharging the crushed ore at the periphery, with
hopper surrounding the top of the chamber, and Figs. 2, 3, and 6 as constructed with
the discharge in the centre of the bottom of the chamber, and the hopper at one
side.
A and B are the upper and lower parts respectively of the annular chamber, C the
ring-plate which is bolted to the flanges of the parts A and B, D the balls in the
chamber, E the vertical shaft placed in a cylindrical bearing F, G is a driving pulley
fixed on the top of shaft E, H is an attachment of arms fixed on the shaft and
depending therefrom into the chamber, having at one end of each arm an aperture I
in which the driving block is fastened by set screws, and at the other end of the arm
a scraper J, which keeps the ore from collecting at the bottom of the chamber; from
the flange of the lower part of the chamber B lugs K project, through which are set
screws K' for adjusting the sections of the ring-plate, L is a conical screen through
which the ore is discharged into a receptacle under the annular chamber, C are
distance pieces on the ring-plate having elongated bolt holes, through which bolts are
placed, fastening the upper and lower portions to the ring-plate, between these distance
pieces are apertures L', through which the ore is discharged at the periphery by the
centrifugal action of the balls, M are blocks of wood placed between the sections of
the ring-plate, N is a hopper at the side of the mill, and N a circular hopper
surrounding the upper part of the chamber.
Instead of the bearing for the driving shaft being fixed above the chamber, and the
shaft driven by a pulley attached thereto, we may place the bearing for the shaft at
or below the base of the chamber, and allow the shaft and the propelling attachment
to work from the bottom of the chamber instead of from the top, which will involve
an evident alteration of the details in the propelling arms; this arrangement will be
especially convenient when the crushed ore is discharged at the periphery; the
propelling power may also be conveyed to the shaft by gearing or other means instead
of by the pulley as shown and described.
The operation of the mill is as follows:-The ore or other material having been
placed in the hopper, the vertical shaft with the arms attached is set in motion by
the means provided, and the balls will rotate, and by their centrifugal action will
operate with considerable force on the material passing between then and the inner
surface of the chamber, reducing it to the required fineness, and discharging it through
the channel or channels provided therefor.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The grinding mill substantially as described and shown, consisting essentially of
a fixed annular chamber in which balls are made to rotate and crush the material by
their centrifugal force.
2. The adjustable horizontal ring-plate, formed in sections, so that as it becomes
worn its inner circumference may be restored to the original. size; the whole plate
being bolted to the upper and lower casings, whereby the chamber acquires rigidity
and freedom from vibration.
3. The insertion of blocks in the propelling arms, and the means of adjusting and
ixing the same, substantially as described and shown in Fig. 7 of the accompanying
drawings.

page_text: 4. The placing the driving shaft with its bearing outside the grinding part of the
mill, so that the wear and friction are reduced to a minimum.
5. The discharge of the crushed ore by centrifugal force through the apertures in
the periphery, as and for the purpose described and set forth in figs. 4 and 5 of
the accompanying drawings.
1000
J. G. WESTLAKE,
Applicants' Agent.