IMPROVEMENTS IN FIXING AND BALANCING VERTICAL MILL STONES to be as follows:
Year: 1885

page_text: We ROBERT ASHTON LISTER and GEORGE SHAW RICHMOND, both of Dursley;
in the county of Gloucester, Engineers, do hereby declare the nature of the said
invention for "IMPROVEMENTS IN FIXING AND BALANCING VERTICAL MILL STONES
to be as follows:-
=
"
This invention relates to improvements in the method of fixing the bed or fixed
stone, and fixing and balancing the runner stone in vertical stone mills.
In carrying out our improvements as applied to the
in a cast iron case, by means of a suitable number of
and fastened in the stone, by means of cement or lead.
through corresponding holes in the cast iron case and
the opposite side.
bed stone, we fix the same
bolts which are built into,
The said bolts are passed
secured by screw nuts on
In fixing and balancing the runner stone according to our invention, we employ
a cast iron pan with a central boss, in which pan the stone is placed and is suitably
fixed by means of bolts, cement, or otherwise; on the outside of the pan we cast or
fix a number of ribs which radiate from the centre to the circumference, and we
also cast or otherwise fix corresponding ribs on the outer edge of the pan in an
inclined direction; these ribs are for the purpose of creating a rapid rotary motion
to the air within the case, and also for maintaining a steady lateral pressure
keeping the stone in equilibrium; a number of holes are cast in the back or
bottom of this pan for the purpose of equalizing or balancing the weight of
the stone.
When the stone is too large to be placed in a pan of the above description we
shrink a wide band on to the stone and attach ribs such as are above described.
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page_text: Improvements in Fixing and Balancing Vertical Mill Stones.
We ROBERT ASHTON LISTER and GEORGE SHAW RICHMOND both of Dursley
in the county of Gloucester, Engineers 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 relates to improvements in the method of fixing the bed or fixed
stone and fixing and balancing the runner stone in vertical stone mills.
In carrying out our improvements as applied to the bed stone we fix the same
in a cast iron case by means of a suitable number of bolts which are built into
and fastened in the stone by means of cement or lead the said bolts are passed_
through corresponding holes in the cast iron case and secured by screw nuts ou
the opposite side.
In fixing and balancing the runner stone according to our invention we employ
a cast iron pan with a central boss in which pan the stone is placed and is suitably
fixed by means of bolts cement or otherwise on the outside of the pan we cast or fix
a number of curved ribs which radiate from the centre to the circumference and
in an
we also cast or otherwise fix corresponding ribs on the outer edge of the pan
inclined direction a number of holes are cast in the back or bottom of this pan for
the purpose of equalizing or balancing the weight of the stone.
When the stone is too large to be placed in a pan of the above description we
shrink a wide band onto the stone and attach ribs such as are above described.
In order to enable our invention to be fully understood we will proceed to
describe the same by reference to the accompanying drawing in which figure 1, is
a transverse section of a vertical stone grinding mill having the grinding stones
fixed and balanced according to our invention; figure 2 is a central longitudinal
section of same; figure 3 is a detached back elevation of the runner stone fixed in
its pan; figure 4 is a plan of the same; figure 5 is a detached back elevation and
figure 6 a plan of the bed or fixed stone in its casing. Similar letters in all the
figures represent similar parts.
A, figures 1 and 2 is a hopper or receptacle for the corn or material to be ground;
B is a shaking shoe in which is placed a wire sieve to prevent nails or the like
from getting into the mill; this shoe is raised or lowered by means of a hand
wheel and chain; C, C, are iron arms (four in number) for carrying the hopper;
D is a round iron casing; E is a cast iron frame or stand with four legs, F, is a
spout for delivering the meal into a bin or sack; G, is a damsel driven by friction
wheel running on the boss of the driving pulley; H is a driving pulley keyed on a
turned horizontal shaft J, running horizontally in two long bearings in each
casting; K is a hand wheel and screw for adjusting the runner stone; L is a
locking lever for securing the hand wheel and screw when so adjusted; M, is a
worm for bringing the corn to the face of the stones; N, is a box casting forming
a passage to lead the material to be ground to the worm all the said parts being of
ordinary construction.
O is the bed or fixed stone and A¹ is the iron case in which the stone is fixed;
B', B', are the bolts built into and fastened in the stone as shewn in figures 2 and 6

page_text: by means of cement or lead; C1, C¹; are the screw nuts on the ends of the bolts B¹
outside the case A¹ through corresponding holes in which they are passed.
The chief advantages of this method of fixing the bed stones of grinding mills
over the means usually adopted such as wedges, cement, or, set screws is that the
stones are more securely fixed and easier to remove and refix without skilled
labour either for convenience of transit or for changing the stones.
P, is the runner stone and Q is the iron pan in which it is fixed by means of
bolts, cement, or otherwise; D', is the central boss on the pan Q; R, R are the
radial curved metal ribs cast or otherwise fixed on the outer surface of the pan Q;
Rare the inclined ribs on the outer edge of the pan Q and corresponding with the
radial curved ribs R; S are the holes cast in the back or bottom of the pan Q, for
equalizing or balancing the stone.
The main object of the ribs R being curved on the side and the ribs R¹, being
formed at an angle on the periphery is to effect a perfect centrifugal balance at the
same time producing a lateral pressure against the adjusting screw; the advantages
gained are two fold videlicet causing a rapid circulation of air which prevents the
material being ground from clogging against the inner surface of the iron casing
and preventing the faces of the stones running together when empty.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that
what we claim is
1. Fixing the runner stones of grinding mills in a pan provided with ribs
substantially as and for the purpose hereinbefore described and represented in
the accompanying drawing.
2. Bolting the fixed stones of grinding mills in a case substantially in the
manner and for the purpose hereinbefore described and represented in the accom-
panying drawing.