Year: 1888

page_text: I, FRANK BOWDITOH MORSE, residing at Murphys, in the county of Calaveras,
State of California, one of the United States of America, Mining 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 to that class of ore-concentrators in which an endless traveling
belt is employed, and to which a positive shaking motion is imparted.
My invention consists in a concentrator, the endless traveling belt of which is
formed or provided with an operating-surface of the peculiar character hereinafter
fully described.
Referring to the accompanying drawings,
Figure 1 is a perspective view of the ore-concentrator, showing my belt.
Figure 2 is a longitudinal section of the belt, showing the peculiar character and
form of its surface.
Figure 3 shows the short vanning-surfaces connected by curved surfaces.
My invention is applicable to any of the endless-belt concentrators. These machines
differ from one another in details of construction relating to the frame-work and the
mechanisms for imparting to the belt its several motions, but they all resemble one
another in the employment of a common feature, namely the endless traveling belt
to which a positive shake is imparted.
These belts have been made of canvas, especially the earlier ones, but they are now
made of rubber. Their sides have guard-flanges, and their surfaces smooth.
"
They are set at a slight inclination and have imparted to them what is known
as an "uphill travel, at the same time receiving a supplementary motion which is
known as a "shake," this latter being either side-wise, endwise, a rotary movement,
or an eccentric movement, resulting from the combination of simple movements.
:

page_text: In the accompanying drawings I have shown a machine of this class which is
well-known, and which will require no further description than to say that the
endless belt is supported at an inclination upon a frame B, to which a shake is
imparted, said belt having an uphill travel and passing down underneath through a
washing-tank whereby the sulphurets, which cling to its surface are deposited, the
ore being fed on the surface of the belt, together with a stream of water.
The general operation is that the stream of water flowing down the inclined belt,
carries the lighter or waste particles of the pulp with it to the lower end, while the
heavier particles or sulphurets cling to the surface of the belt and proceed upwardly
with its travel, against the flow of water, pass around the upper end, and are deposited
in the tank below.
This is the operation of all machines of this character.
Now, instead of using the ordinary belt with a flat or smooth surface, I employ an
endless belt. A, the surface of which is formed as I shall now describe.
By referring to Figure 2, it will be seen that the surface of the belt consists of
a continuous series of short vanning-surfaces a, rising at a considerable angle from
the general grade of the belt. said angle being such that when taken in connection
with the incline of the belt, the surfaces of these vanning-planes would intersect, if
extended, a horizontal line.
These elevated vanning-surfaces are connected by a series of steep inclined
surfaces a¹. This form of surface changes the vanning-surface of the belt from a
surface depressed from a horizontal line, as in a smooth belt, to a surface elevated or
rising from a horizontal line.
This operation of this belt is as follows:-
:-
The water and pulp flow down the depressed surfaces a³, and are forced up and
over the elevated surfaces a, and on these latter surfaces the vanning or separation of
the lighter and heavier particles takes place.
In a smooth depressed surface, as on a plane-surfaced belt, the separation depends
entirely upon the adhesion of the heavier particles to the belt. But by having these
vanning-surfaces a, clevated, as shown, there is, instead of the adhesion of the heavier
particles, a separation due to the difference of suspension-gravity of the particles in a
current of water.
The current of water flowing up the inclined elevated surfaces a, will take with it
the sand or particles having a lighter suspension-gravity, while the sulphurets or
particles having a heavier suspension-gravity will move downwards on these surfaces
through this current of water and lodge in the angles between a, and a².
In this way the vanning-surface of the belt becomes a positive one, dependent upon
the suspension-gravity of the particles flowing over it, and not merely a nominal one,
as in the case where such surface is depressed, as in a smooth belt.
This elevation of the vanning-surface greatly facilitates the action of separating,
vanning, or concentrating, and does the work on a much shorter belt.
The vanning-surfaces a must, necessarily, be comparatively short in order to insure
the upward flow of the water on them.
The length of such surfaces and their grade is determined by the size of the
average particles of pulp which pass over them, but with a definite length of such
surfaces. The force of the current of water over them, and the inclination of the
surfaces can be regulated at the same time by raising or lowering the average or
general grade of the belt. A much shorter belt of this description will do better
and cleaner work than an ordinary plane-surfaced belt. It will work with a thin
stream of pulp, instead of requiring a heavy load. A larger stream of water can be
used, and any variation in the amount of pulp may be permitted, a thing which would
be fatal to a plane depressed-surfaced belt.
In Figure 3 the sharp angles between surfaces a, and a¹ is avoided by making
surfaces a curved.
This construction is generally preferable, as the change of the current is made more
smoothly and effectively.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is,
1. In a concentrator, an endless traveling belt, mounted at an inclination, and
having its working-surface composed of the series of short transverse, upwardly-
inclined vanning-surfaces a, and the downwardly-inclined surfaces a¹ connecting them,
substantially as described.
2. In an ore-concentrator, the combination of a supporting-frame, an endless
traveling belt mounted at an inclination therein, and having its working-surface
composed of the series of short transverse vanning-surfaces a, elevated or inclined
from the horizontal, and the downwardly-inclined surfaces a¹ connecting them, and
means substantially as described for vibrating said belt.
Dated this Twenty fourth day of July 1888.