Improvements in Appliances for Facilitating the Extraction of Precious Stones from Earthy and other Deposits.
Year: 1889

page_text: Date of Application, 23rd Oct., 1889
Complete Specification Left, 25th Aug., 1890-Accepted, 27th Sept., 1890
PROVISIONAL SPECIFICATION.
Improvements in Appliances for Facilitating the Extraction of
Precious Stones from Earthy and other Deposits.
We, GEORGE MIDDLETON EDWARDS of No. 20 Dinsdale Road Blackheath S.E. in
the County of Kent Manufacturer, and WALTER JAMES GRIFFITHS of No. 22 Annandale
Road East Greenwich S.E. in the County of Kent, Engineer do hereby declare the
nature of this invention to be as follows:-
Our improvements relate to appliances for treating the earthy matter in which
precious stones are commonly found and getting rid of the earthy and soluble part
and delivering the stony portion in a suitable condition for more easily detecting and
picking out stones of value as gens.
For the purpose of our invention the earth or other matter containing precious
stones is fed into a launder or trough from which it is carried by a stream of water
into a revolving barrel about 5 or 6 feet more or less from the ground level.
This barrel is mounted on hollow trunnions with its axis slightly inclined from its
head or intake end.
The feed passes in through the higher trunnion and the revolving of the barrel
causes the earthy matter to become well mixed with the water and thus cleanses the
stony portion.
If clay be present in the mixture the cleansing process may be facilitated by fixing
spikes or bars inside the barrel.
When the barrel revolves, the water and solid matter flow out at the lower trunnion
at a rate depending on the feed, the barrel being always about half full.
One or more spiral scoops of metal or other suitable material fixed inside the barrel
at its lower end insure the picking up of the stones, and turning them out through the
lower trunnion.
Connected to the lower trunnion and revolving with it and the barrel, we make use
of a cylindrical sieve of suitable mesh, in which the whole of the discharge from the
barrel is continuously received.
The water, earthy matter and smaller stones pass through this sieve into one shoot,
the larger stones are thrown out at the end of the sieve into a shoot conveniently
placed to receive them or the sieve may be made in two or three sections with different
sized holes so as to sort the stones into different sizes.
The stones from the shoot or shoots may conveniently pass on to sorting tables and
other appliances may be used to treat and be fed with the smaller stones and other
matter which pass through the mesh of the sieve.
For this latter purpose we advantageously make use of an appliance for which
Provisional Application was made by one of us, namely George Middleton Edwards
numbered 8147 of 1889.
For the purpose of turning the barrel we make use of gear worked by hand or other
power.
Dated thin 91st den of Octob^, 1980

page_text: COMPLETE SPECIFICATION.
Improvements in Appliances for Facilitating the Extraction of
Precious Stones from Earthy and other Deposits.
We, GEORGE MIDDLETON EDWARDS of No. 20 Dinsdale Road, Blackheath S.E. in
the County of Kent, Manufacturer, and WALTER JAMES GRIFFITHS of No. 22 Annandale
Road, East Greenwich S.E. in the County of Kent, 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:-
:―
Letters Patent, dated 16th May 1889 No. 8147, were granted to one of us, namely
G. M. Edwards, "for improvements in machinery and appliances for separating and
cleaning auriferous and other mineral ores and substances, and also precious stones
from their gangue and other associated refuse matter," and part of the processes
therein indicated consisted in the use of sieves to prevent stones passing into the
lower or washing division of the machine.
As, however, it is found in practical gem washing that the precious stones are often
in association with refuse matter, other than that of a sandy nature, such as the
substance technically known as "blue" and various kinds of clayey earths, which will
not readily pass through the sieving appliances above mentioned without causing delay
and necessitating undue manipulation in feeding the machine; our present improve-
ments in this process consist of and are effected by the use of combined mechanical
appliances, which greatly reduce the difficulty of dealing with material of the adhesive
nature above alluded to.
According to our present invention we make use of mechanical appliances in the
following order of arrangement:-
:-
First. The substance containing gems is fed together with water into a feed launder,
in which are placed revolving metal cutters or wire brushes acting from below between
the bars of a grating, the spaces between which are sufficiently small to keep from
passing out of the feed launder all stones above a certain size, for instance, an inch
diameter.
The smaller stones and all other matter carried by the water pass down and out of
the launder into a revolving drum, made of wood, iron, or other suitable material,
which by its revolving action not only retains for an appreciable time the solid matter
under the influence of the wash of the water, but by the same action causes the soft or
clayey portion of the material to be broken up and fretted away by rough contact
with the stoney portion of such material.
Secondly. The whole of the water borne material is, by means of a scoop or scoops
placed at the lower end of the revolving drum, gradually extracted from the drum
and passed on into a revolving sieve of suitable mesh, for example, a quarter inch,
more or less, which prevents stones above that size from passing into the next division
of the washing appliance, into which all water and matter not retained by the sieve is
allowed to pass.
Whilst the stones are in the revolving sieve, their retention therein being prolonged
by means of a disc of metal filling up its lower end, provided with only a narrow
opening for their exit, they are played upon by jets of clean water continuously ejected
through holes in a metal pipe placed longitudinally in the middle of the sieve, which
further cleanses them from earthy or other soiling matter.
Thirdly. From the lower end of the revolving sieve these stones are delivered down
a shoot, into a receptacle conveniently placed to receive them, previous to their
removal for close inspection and extraction of gems.
These receptacles we make advantageously of galvanized sheet iron, and of
rectangular or box form, and during the discharge of stones from the end of the
revolving sieve they are secured from theft by the box lid being locked, leaving only
a small aperture by which the stones or gems enter.
Fourthly. The water borne material passing through the revolving sieve which
contains any gems sufficiently small to go through the mesh used, passes on for

page_text: further washing, for which purpose we advantageously use the appliance shown in the
Specification to Patent No. 8147 of 1889, see drawing, sheet No. 1, thereto
annexed.
As, however, only stones of appreciable size, for example, those which will be
retained by a mesh of eight holes to the linear inch, are generally required to be
obtained in gem washing, all materials smaller than this can be disposed of.
For the sake of retaining stones of the above size, we place underneath each valve
in the patented appliance before alluded to, an open box sieve which slides into and is
supported by an apparatus for jigging or shaking out all material which will pass
through the sieve.
For facilitating this last process the sieves work in a shallow tank of water placed
underneath them, the water level being advantageously kept about half an inch above
the level of the wire mesh of each sieve, and the solid matter accumulating in the
tank being removed as required.
The sieves are easily removable and a clean sieve should be used each time the
valve is open for discharge.
The stones retained by the sieves can at once be emptied into any convenient
receptacle.
For turning the barrel and working the other parts of the machinery, we make use
of gear worked by hand or other power, see F, Sheets 1 and 3.
Now in order that our improvements may be clearly understood and readily carried
into practice, we will proceed to illustrate the same by and describe the drawings
hereto annexed.
Figure 1 of the drawings is a longitudinal section of a gem washing machine, the
earthy and other material and water aro fed together into the feeding launder or
box A, in the bottom of which the wire brushes B, revolve, which separate and break
up any clay lumps that may be in it.
The flow of water carries the gravel and other substances into the revolving drum
or barrel C which mounted on hollow trunnions with its axis inclined from its intake
end, cleans the stones by causing them to rnb against one another-in the after end
of this barrel is a spiral scoop D, for picking up and discharging the stones out of the
lower trunnion, this scoop is shown again to a larger scale in Figure 3, it will be
noticed that the scoop extends to the periphery of the barrel, but, as it is advantageous
to retain a quantity of stones always in the barrel, a stop may be fixed at any suitable
place on the scoop and limit its action.
The discharge out of the barrel goes into the revolving sieve E, the smaller stones
and water falling through on the inclined surface G₁ and the larger stones, after being
further washed by the clean water thrown out from the perforated central pipe, fall out
of the end of the sieve into a shoot that carries them out at the side of the machine
and deposits them into a locked iron box or other receptacle.
The inclined surface G₁, we prefer to extend into channels of the description for
which a patent was granted, to one of us, viz., G. M. Edwards, dated 16th May 1889,
No. 8147, and this part of the machine is exactly as described in that patent, the only
addition being that the discharge from the channels is received in H₁ and H, which
are placed on a swinging frame in a tank of water, the frame having a reciprocating
motion given to it by the bell crank L and rods connected to it.
Figure 5 shows another arrangement that may be used for working the jigging
sieves, the frame on which these sieves H, H, stand receiving a combined vertical and
horizontal movement, from the revolving of the shaft P having small cranks on the
ends to which the links connected to the frame are attached.
Figure 2 shows a transverse section of the feed box, drawn to a larger scale, the
part of the shaft on which the wire brushes go is square, and a number of cast iron
discs with notches in them for the wire bundles are placed on one after the other.
R is the end view of one of the discs, the bundles of wire are made on a ring as shown
at S and are slipped over the shaft into the disc, a cotter through the shaft tightens up
the last disc, and holds all the brushes in place, inside the box A a number of iron
bars, such as K, are fixed between the brushes so as to form a grating and cause the

page_text: gravel and other material, as it is shoveled into the feed launder, to go to the side
where the brushes are turning upwards; stones of such a size as can pass between
this grating are carried through by the brushes and lumps of clay or earth are broken
up thus.
The brushes are arranged on the shaft so as to cause big stones, that cannot pass
through the grating, to move along by their screw arrangement up to the back end of
the feed box, where the large stones are taken out as they accumulate.
Figure 4 shows another arrangement of the feed box, the shaft and bottom of the
box Leing inclined, and the brushes continued the full length of the box; at the back
end of the box a hole N, is made in the side and as the big stones are worked back by
the brushes they fall out of the hole without the trouble of removing them by hand.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed, we wish it to be understood that we
do not limit ourselves to the exact details hereinbefore described and illustrated in the
drawings, as they may be varied without departing from the nature of our invention,
at the same time we do not claim any of the parts separately which are well known,
but we declare, that what we do claim as our invention is :-
The general combination and arrangements substantially as herein before specified
and shown in the drawings hereto annexed.
Dated this 22nd day of August 1890.
GEORGE MIDDLETON EDWARDS.
W. J. GRIFFITHS.