Improvements in Ore Concentrators.
Year: 1896

page_text: Date of Application, 21st Mar., 1896-Accepted, 2nd May, 1896
COMPLETE SPECIFICATION.
Improvements in Ore Concentrators.
I, FRANK JOHN WOODS, of 369 Washington Boulevard, Chicago, Cook
County, Illinois, United States of America, 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 :-
My invention relates particularly to mining machinery adapted for use in placer
mining, and especially to machinery for concentrating precious ores by what is
known as the "dry process;" and has for its object the providing of a simple,
economical and efficient machine, particularly adapted to the concentrating of
gold-bearing dirt by the "dry process." The invention consists in the features,
combinations and details of construction hereinafter described and claimed.
In the accompanying drawings,
Figure 1 is a longitudinal vertical sectional elevation of my improvement;
Fig. 2 a transverse section of a portion of the mechanism taken on line 2 of
Fig. 1, looking in the direction of the arrows;
Fig. 3 a transverse section of a portion of the mechanism, taken on line 3 of
Fig. 1 looking in the direction of the arrows;
Fig. 4 a detail view of the crank shaft for vibrating the riffle board and
other parts;
Fig. 5 an enlarged transverse section of a portion of the mechanism, taken on
line 5 of Fig. 1 looking in the direction of the arrow;
Fig. 6 a side sectional elevation of a portion of the mechanism, taken on line 6
of Fig. 5; and
Figs. 7 and 8 detail views of a portion of the side bar and riffle board as
hereinafter explained.
In the art to which this invention relates, it is well known that the use of this
"dry procéss" is considered very economical and useful, owing to the fact that it
can be used in a great number of places where the wet and similar processes
cannot be used, owing to the fact that the necessary supply of water cannot always
be obtained for the successful operation of such machines. It is also well known
that there are very few, if any, machines of this particular "dry process" class in
successful operation, owing to the fact that they are generally lacking in some
essential elements, which have prevented their introduction to any appreciable
extent.
In this particular class of machinery, there are three general requisites which
should be combined to form a practical organized machine: (1) The material
or gold-bearing dirt should be fed into the machines in a uniform, pulverized or
disintegrated condition and in uniform quantities; (2) the machine should be
constructed of as few parts as possible, so as to minimize the expense of repairs
and allow it to be operated or repaired by the ordinary laborer; and (3) the
mechanism should be so constructed that that portion which holds the concentrates
may be readily removed or replaced so that such concentrates may be economically
obtained. My invention, therefore, is intended to obviate the objections found in
existing machinery, and to provide an organized machine which has the three.
general characteristics above noted-one that will concentrate gold-bearing sand.
or clay and eliminate the tailings in a simple, economical and efficient manner.
In constructing my improved concentrator, I make a frame, A, preferably of
timber, and of the desired size, shape and strength to support the other parts of the

page_text: machine in the desired arrangement. Secured at a desired angle, so as to enable
the gold-bearing dirt to pass readily down the same, is a riffle screen, B, provided
at regular intervals with riffle bars, b. These riffle bars-as shown particularly
in Figs. 6, 7 and 8-are made in several pieces screwed together, the ends of the
transverse portion, 6', of which enter a groove, , in the side bars, so that when
necessary such riffle bars may be readily removed or replaced. This riffle screen
and bars are supported in suitable framework, B', and inclosed to form a riffle box,
so that the fine dust is prevented from permeating the surrounding atmosphere
and compelled to pass out through the exit, 63, in the lower portion of the riffle
channel. To inclose this riffle screen and bars and provide a riffle box and
channel, I provide two side boards, C, which are slotted or grooved and held in
position by means of the dowels, c. These side bars are raised and lowered by
means of the hand screws, C, which have their threaded portions supported in
brackets, C, and their lower headed portions engaging with suitable recess lugs, c³,
on the side boards, so that by the rotation of these hand-screws the side boards
are raised and lowered as desired. The lower portion of the side boards and the
upper portion of the side bars are bevelled inwardly as at c, so that when the side
boards are raised any dust or material on the side bars may be brushed inwardly
on the riffle screen. A dust cover, C, is provided, formed of metal and entered
in grooves in the side wall. To lock this cover in position I provide a spring
hasp, c, which is adapted to engage with a staple, c, on a cross bar of the riffle
box, so that the riffle channel formed by the different parts may be securely locked
and the contents protected. The upper portion of the riffle channel is closed by a
flap valve, D, which opens inwardly towards the rifle channel to permit material
to enter, but prevents the passage of any of the material upwardly and
backwardly.
A suitable apion, D¹, is secured to the upper portion of the riffle box to provide
means by which the crushed or disintegrated material may be fed into the riffle
channel, and I provide a number of permanent magnets, E, in the pocket of such
apron for the purpose of gathering up any iron ore or metal which may enter with
the material.
To furnish current of air upward through the riffle screen and blow out the
lighter dirt, clay and dust, I provide a bellows, G, of the desired size and shape
and having the desired number of folds, and secure the same to the under side of
the riffle screen. A number of springs, g, is provided between the slats of the
different folds of the bellows to balance the weight of the parts and provide for a
uniform closing and opening of the bellows.
In order to vibrate the bellows, I provide a crank shaft, H, and connect its
cranks, h, with the lower portion of the bellows by means of the connecting rods, h¹,
so that during the rotation of the crank shaft the bellows is vibrated the desired
amount and a current of air formed up through the riffle screen.
It is necessary that the riffle box with its screen and suspending parts be given
a jigging or vibratory motion for the purpose of disturbing the material and
allowing the air current to carry off the lighter portions. In order to do this,
I flexibly mount the framework of the riffle board upon four flat, metallic springs, I,
one end of which is secured rigidly to the supporting framework and the other
ends to the framework of the riffle-box. These flat, metallic springs allow the
riffle-box to be shaken or jigged in the desired direction, and at the same time
prevent undue or unnecessary vibration, while providing a sufficient support for
the mechanism during the jigging or vibrating. I provide a second crank shaft, K,
which is mounted in suitable bearings on the supporting framework, and connect
its crank portions, by means of connecting rods k, with the brackets k', on the
upper portion of the riffle-box, so that the rotation of this shaft will give the
necessary vibration to the parts.
To disintegrate or crush the gold-bearing dirt into a uniform condition and feed
it into the riffle-box in the desired quantities, I provide two rotating shafts, L, L',
with angular intermeshing beaters, 1, 1, with their angles set with regard to the

page_text: rotation, so that as the material is struck, disintegrated and crushed, it is fed in
the direction of the riffle-box and into it in the desired quantities. These beaters
or disintegrators are surrounded by a suitable casing, L', to provide a com-
partment in which the material may be held as it is disintegrated and fed
forward.
To actuate the different parts of the machine, I provide a main driving shaft, M,
and connect its different pulleys by means of a chain, m, and belt, m', and inter-
mediate gears with the crank shafts, H, K, and rotating shafts, L, L', so as to
impart motion thereto. Any desired motive power may be used and connected
by suitable mechanism with the main driving shaft, M, for the purpose of operating
the mechanism.
The principal advantages incident to the use of my improvements are (1) that
I have provided an organized, compact machine in which the material is dis-
integrated and reduced to a uniform condition and fed into the machine in uniform
quantities. This advantage will probably be better appreciated when it is
considered that if the material-especially gold-bearing clay-is not disintegrated
just as it is fed into the riffle-box, there will be a tendency to "pack" or "lump,"
and thus interfere with the practical operation of the machine. (2) The mechanism
is very simple and economical in construction so that the ordinary laborer may
operate or repair the same, thus dispensing with the necessity of having skilled
and expensive help, which is usually very difficult to obtain where "dry" placer
mining is carried on; and (3) the riffle bars may be readily taken out, thus
rendering the obtaining of the "concentrates very easy and economical, as well
as permitting the obtaining of a larger per cent. of the same.
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 dry ore concentrators, an organized machine in which there is combined
an inclined riffle box provided with a riffle screen on its lower surface, a vibrating
bellows arranged below such riffle screen and adapted to furnish a current of air to
separate the materials, a disintegrator formed of at least two rotating shafts having
intermeshing beaters adapted to disintegrate the material and feed it forward in
uniform condition and quantities into the riffle-box, flat metallic springs to flexibly
support the riffle box and suspending parts, means for actuating the bellows for
imparting a jigging or vibratory motion to the riffle box and secured parts, and
means for operating the mechanism, substantially as described.
2. In dry ore concentrators, an organized machine in which there is combined'
an inclined riffle box having an inclosed riffle channel formed of a lower riffle
screen with transverse riffle bars, adjustable side boards, a removable cover and a
flap valve, a bellows secured to the riffle-box directly under the riffle screen for the
purpose of furnishing a current of air to such riffle screen and separate materials,
flat spring mechanism for flexibly supporting the riffle bars and secured parts on
the framework, means for actuating the bellows, means for imparting a jigging or
vibratory motion to the riffle-box, a disintegrating feeding mechanism consisting of
at least two rotatable shafts provided with angular beaters or disintegrators for
crushing and feeding the material in uniform condition and quantities into the riffle
box, and means for operating the mechanism, substantially as described.
3. In dry ore concentrators, an organized machine in which there is combined
an inclined riffle-box composed of a lower riffle screen having riffle bars removably
secured thereon, adjustable side boards, a removable cover and automatic flap
valve at the entrance, a bellows secured to the riffle box beneath the riffle screen
to furnish a current of air to the same and separate materials, flat spring mechanism
for flexibly supporting the riffle-box and secured parts on the frame, means for
vibrating the bellows, means for imparting a jigging or vibratory motion to the
riffle box, disintegrating feeding mechanism composed of at least two rotatable
shafts provided with angular intermeshing beaters for crushing and feeding the

page_text: material into the riffle-box in their uniform quantities and condition, and means for
imparting motion to the different mechanisms, substantially as described.
4. In dry ore concentrating machinery, the combination of a bellows provided
with a perforated top, means for concentrating and expanding the bellows, means
for feeding material to and over the perforated top, robs or ledges for actuating
and retaining the heavier particles of the material as it passes over the top, and
side bars vertically adjustable to permit the removal of the bars or ledges,
substantially as described.
Dated this 21st day of March 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.