An Improved Sifting Device for the Treatment of Gravel and the like.
Year: 1894

page_text: Date of Application, 29th Mar., 1894-Accepted, 5th May, 1894
COMPLETE SPECIFICATION.
An Improved Sifting Device for the Treatment of Gravel and
the like.
I, GUSTAV FREUND, of Giebichenstein, near Halle, on the Saale, in the German-
Empire Manufacturing 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 :—
The subject of this invention is a sifting device for the treatment of gravel and
the like by means of which such material is washed and obtained in almost uniform
sizes, while the capacity of this device as to quantity exceeds by twice or three-
times all other devices hitherto known or used for the purpose.
In order that my invention may be the better understood, I now proceed to-
describe the same, reference being had to the accompanying drawings and to the
letters and figures marked thereon. Like letters refer to like parts in the various
figures.
Figure 1 shows the arrangement of the device in sectional elevation.
Figure 2 is an end elevation of the same and Figure 3 is a transverse section of
the sieve on the line a-b.
The device which serves for the treatment of the gravel consists of a sieve c,.
constructed of bars of iron &c. supported at suitable places by transverse pieces,.
and a lower part or shoot e.
The face of the sieve c is straight at its upper part, but from the line f. towards.
the end its bars are laid in a curve so that the sieve assumes a shallow trough form
at its lower end.
The sieve is suspended in the ordinary manner and at an angle suitable to the
grade or size of the gravel. Several sieves constructed in the same manner may
be placed beside one another so as to form an installation on a large scale. In such
cases the size of the spaces between the sieves and the size of the sieving surface.
depends upon the size of the wagons in which the washed gravel is to be received
and carried away.
Above the sieve is a hopper 9 and a water reservoir h of corresponding length..
The gravel to be treated is fed into the hopper g and falls out on to the sieve c
through an opening in the bottom of the hopper 9 which is made adjustable by a
movable slide i.
g
The water reservoir is provided with a number of small orifices k arranged
longitudinally through which the water, flowing into the reservoir is delivered on
to the sieve c. The opening in the hopper g is adjusted by means of the slide i, in
accordance with the flow of water and the amount of earthy matter mixed with the
gravel in such a manner that the gravel and water meet on striking the sieve. By
means of the streams of water pouring over the whole surface of the sieve the
earthy substances mixed with the gravel, such as clay &c. are dissolved and carried
away from the gravel while at the same time the small particles of the gravel fall.
through the perforations of the sieve c.
The washed out earthy matter, the small particles of the gravel and the water
pass through the perforations of the sieve c into the lower part or casing e below
the sieve c and from thence fall through the exit funnel m into an exit channel n.
from which they escape to any suitable place.
The granular gravel passes down along the bare of the sieve c and is passed
through the trough shaped part of the sieve into the wagon a.
The function of the sieve is continuous and automatic, entirely free from all
manual manipulation so long as the gravel is fed into the hopper.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is,
1st. A sifting device for the treatment of gravel and the like consisting of
longitudinal bars arranged beside one another at intervals rigidly carried by
transverse bars in such a manner that the whole sieving surface is straight at the
upper part and is gradually transformed to a trough shape at the lower part.
2nd. The arrangement and construction of a sifting device substantially as
described and illustrated in the accompanying drawings.
Dated this 29th day of March 1894.
FELL & WILDING,
Agents for the Applicant.