Mineral Ores, or other Substances.
Year: 1887

page_text: Mineral Ores, or other Substances.
I, HENRY LAWRENCE, of Durham, in the County of Durham, Engineer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement and accompanying drawing, that is to say :—
This invention relates to machinery or apparatus used for screening, or separating
into pieces of different sizes, coals, mineral ores, or other mineral or other substances.
For this purpose it is usual to use inclined screens of metal bars, or perforated
plates, or wire, made to vibrate backward and forward by steam or other convenient
power, the coals or other substance to be treated being supplied to the upper end
of the screen and being delivered at its lower end, the small pieces and dust passing
through the screen into a separate receptacle. In such machines it is important that
the screen should vibrate backward and forward with considerable rapidity in order
to produce the most effective result, and my invention has for its object novel methods
of making and arranging the apparatus by which the screens are actuated in such
imanner that whilst they are made to vibrate rapidly backward and forward, the
driving shaft by which they are set in motion revolves at a moderate speed.
In the accompanying drawing which is in illustration of my invention, figure 1 is
a side view of driving gear by which the screen is caused to make three vibrations
for every revolution of the driving shaft. Figure 2 is a plan of part of the apparatus.
Figure 3 is a side view of a modified form of apparatus in which the screen makes
two vibrations backward and forward for each revolution of the driving shaft.
In figure 1, a is the inclined screen of bars, perforated plates, or other suitable
material suspended by the links b, 61, which are carried by centres c, c², upon the
frame d of the apparatus, so that the screen can vibrate backward and forward for a
short distance. e is the driving shaft, revolving in bearings (not shewn in the
drawing) and driven by any convenient power.
Upon the shaft e is keyed the triple cam which operates upon the ends of the
frame g, preferably with the intervention of the friction rollers h, h². The frame g

page_text: is preferably double (as shewn in figure 2), the cam f working between the two sides.
which have openings fitting upon the central boss of the cam, so as to steady and
guide the frame as it vibrates. To the inner end of the double frame g is attached
the end of a connecting rod i the other end of which is, jointed to the vibrating
screen at k.
When the shaft e is made to revolve, the frame g is made to vibrate backward and
forward by the cam / and to transmit similar vibrations to the screen. It is evident
that instead of a triple cam as shewn, one of any uneven number may be used, the
frame g and the screen a making the same number of vibrations at each revolution of
the shaft e.
In figure 3 is shewn a modified form of arrangement, in which instead of a cam an
excentric and levers are used to operate the screen a.
The driving shaft e has keyed upon it an excentric 1, the strap m of which carries
the excentric rod n, the outer end of which is jointed to the lever o which turns upon
the fixed centre p. The other end of the lever is connected by the link to the
levers which turns upon the fixed centre t, and to the other end of which the
connecting rod i is jointed, which transmits the movement to the screen a. It is
evident, as shewn in dotted lines, that each revolution of the driving shaft e causes
two vibrations backward and forward of the lever s and the screen a.
I do not confine myself to the precise form, arrangement, and proportion of the
several parts of the apparatus, which may be varied more or less according to the
circumstances and the purpose for which it is to be used.
The improved apparatus described and shewn, is simple, strong, easily constructed,
and not liable to get out of order, and as the driving shaft revolves at only a moderate
speed as compared with the vibrations of the screen, there is comparatively little wear
and tear.
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. The combination of the vibrating screen a, cam f, frame g, and connecting rod i,
all arranged and operating substantially as described and shewn in the drawing.
2. The combination of the vibrating screen a and connecting rod i with the excentric 7,
and levers and link o, s, r, instead of the cam, substantially as described and shewn.
Dated this 16th day of June 1887.