Improvements in Crushing or Amalgamating Mills.
Year: 1896

page_text: Date of Application, 28th Sept., 1896-Accepted, 24th Apr., 1897
COMPLETE SPECIFICATION.
Improvements in Crushing or Amalgamating Mills.
I, GEORGE FREDERICK REDFERN, of the Firm of G. F. Redfern & Co., The
General Patent Office, No. 4, South Street, Finsbury, in the County of London,
Patent Agents, do hereby declare the nature of this invention (a communication to
me by Henry Banfield; of Argent Street, Broken Hill, in the Colony of New South
Wales, Mechanical Engineer,) and in what imanner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
My invention relates to crushing or amalgamating mills used more particularly for
the reduction or amalgamation of metalliferous öres, but applicable also to other
purposes in which fine and uniform crushing is required.
For convenience I will describe this invention'as applied to a crushing mill, but it is
to be well understood that by the addition of mercury to the pan or circular race
hereinafter described it is equally applicable to mills used for amalgamating.
My improvements consists essentially in constructing such mills with a pan or
circular race fed from a central shoot, the floor of which pan or circular race is raised
towards the inner rim or wall and descends hy steps, preferably four, in the form of
concentric grooves or channels to the outer rim or wall, and in providing a series of
rolls or discs arranged in pairs each roll or disc being preferably hollowed or 'dished
and of such diameter as to correspond with the groove or channel in which it runs.
The upper edge of the outer wall or rim of the pan or circular race is on the same
level as that of the inner rim or wall and is provided at suitable intervals with lips
or shoots, over which the reduced material discharges for subsequent treatment. The
bottom of each concentric groove or channel is preferably rounded but may be of any
suitable shape. The rolls or discs, preferably sixteen in number are arranged in
alternate pairs and have the periphery shaped to the bottom of the respective concentric
groove or channel. The axle of each pair is-supported at its inner end in suitable
bearings in a circular travelling piece placed over the inner rim or wall of the pan or
circular race, and at its-outer end in a circular bed provided with bevelled teeth and
driven by a suitable gear wheel. By this construction the axles carrying the discs
revolve in their bearings, and the whole of the discs are carried round the pan or
circular, race by revolution of the outer circular toothed bed. The depth of the
pan or circular race increasing in steps towards the circumference, the diameter of
the discs is similarly, increased in regular progression, the smallest disc running
in the innermost and the widest in the outermost concentric groove or channel.
Inside
The pan or 'circular race is fed from a central vertical shoot connected overhead
with a supply hopper, and is provided at its base with four openings capable of
being adjusted by suitable slides in order to regulate the flow of material.
and at the base of the central vertical feed shoot, is placed a foursided pyramid
distributor so as to direct the ore in a constant stream through the respective
openings over the inner wall of the pan or circular race.
In order that my invention may be the better understood, I will now proceed
to describe the same by reference to the accompanying drawings, in which :-
Fig. 1. is a sectional elevation of my improved mill.
Fig. 2. plan of same.
A is a pan or circular race having an inclined bottom arranged in steps. A' inner
wall of pan or circular race A. A outer wall of same. A discharge openings.
A', A, A, A', steps or concentric grooves or channels in floor or bottom of circular
race A., B, B, C, C, hollowed or dished discs arranged in pairs, C running in A,
B in A, C in A' and B' in A. D, D; axles carrying respective pairs of hollowed

page_text: or dished discs. D', D', inner bearing of axles D. D2, D3, outer bearings of axles D.
E centrepiece carrying the inner bearings D₁ of axles D. F circular toothed bed
carrying outer bearings D of axles D. G stays connecting the centre piece E with
the outer toothed bed F. G³ pulleys attached to the stays G. G³, G³, inner and
outer guide rails of pulleys G, G. G supports carrying inner and outer guide
rails G, G. H central feed. H foursided pyramid distributor in central feed H.
H' feed openings discharging over inner wall A of pan or circular race A. I bevelled
driving wheel. I' bearing of same. K bar securing pan or circular race to the bed
for the greater solidity.
In practice the ore is fed from any suitable hopper or other source of supply into
the central feed H and passes in a continuous stream through the feed openings H2
over the inner wall A' and into the innermost concentric groove or channel A* of the
pan or. circular race A. By means of the slides hereinbefore referred to the feed
openings H2 are adjusted in order to control the supply of ore to the capacity of the
mill, and to enable the discharge to be equal to the supply.
The ore fed into the innermost groove or channel A received its first reduction from
the discs (and is.carried on into the next concentric ring or groove A° by the flow of
water provided for the purpose either in the central feed H or otherwise as may be
found convenient. In this way it passes from concentric groove to concentric groove
until the outermost A' is reached and is finally carried over the lips or discharge
openings A3 reduced to the desired fineness.
I wish it to be understood that I do not confine myself to the number of concentric
grooves or channels as shewn, nor to the particular shape of the same. Nor to the
particular number of revolving rolls or discs or to the method by which the whole are
carried round or caused to revolve in the pan, but
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. In crushing or amalgamating mills, a pan or circular race (such as A), the floor
of which is raised towards the inner rim or wall and descends. by steps towards the
outer rim or wall, substantially as herein described.
2. In crushing or amalgamating mills, a pan or circular race (such as A), the floor
of which is raised towards the inner rim or wall, and descends towards the outer rim
or wall, by concentric grooves or channels, (such as A', A5, A6, A',) substantially as
herein described and for the purpose indicated.
3. In crushing or amalgamating mills, the combination with a pan or circular race
(such as A), of a central feed (such as H) provided with suitable feed openings (such
as H2) preferably capable of being adjusted at will and an internal distributor
(such as H') preferably cone or pyramid shaped, substantially as herein described
and for the purpose indicated.
4. In crushing or amalgamating mills having a pan or circular race (such as A) a
series of crushing rolls or discs (such as B, B, C, (",) the periphery of which is
rounded or shaped to the contour of the concentric grooves and the body of which
is preferably hollowed or dished and the diameter of which increases in regular
progression corresponding with the inclination of the floor of the pan or circular
race, substantially as herein described and for the purpose indicated.
5. The herein described mill as a combination of parts, consisting essentially of
a pan or circular race (such as A), having a series of concentric grooves or channels
(such as A to A'), a corresponding series of rolls or discs (such as B, B, C, C)
revolving in and around the same, and a circular feed (such as H) substantially
as herein described and for the purpose indicated.
Dated this 28th day of September 1896
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant..