Improvements in Machinery for Stamping Ore and other Materials and for Collecting Metallic Particles therefrom.
Year: 1893

page_text: Date of Application, 20th Mar., 1893-Accepted, 22nd Apr., 1893
COMPLETE SPECIFICATION.
Improvements in Machinery for Stamping Ore and other Materials
and for Collecting Metallic Particles therefrom.
I, JOHN WESLEY MARSHALL, of 41 Willow Street, Brooklyn, in the County
of Kings, State of New York, United States of America, do hereby declare the
nature of my invention for IMPROVEMENTS IN MACHINERY FOR STAMPING ORE
AND OTHER MATERIALS AND FOR COLLECTING METALLIC PARTICUPS
THEREFROM, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
In the operation of ore stamps, such for instance as those of the type patented
to Charles Sholl, No. 2,524, July 13, 1875, and No. 4,303, Sept. 7, 1883, serious
difficulties have been encountered which it is the object of my present improvements
to obviate.
Where screens have been employed around the coffer of the stamp in order to
prevent the exit of any but the finely and perfectly stamped pulp, the banking of
the partly stamped material in the inside of the coffer against the inner surface of
the screens has left open only the upper portions of the screens and so greatly
retarded the operation of the machine as to be a great practical objection to its
introduction into successful use. According to my present improvement I employ
in combination with the coffer and screen, a spray pipe so situated as to clear the
lower portion of the screen, in consequence of which the upper portion will be
kept clear by gravity and the whole surface of the screen left at all times free to
permit the exit of the finished pulp.
It has heretofore been attempted to collect within the coffer and before the pulp
has escaped into the outside trough a portion of the precious metals contained in it,
but this has not been performed efficiently or with any great amount of success.
By my improvements, I have arrested the precious metals at such points in the
coffer and in such manner as to collect from the pulp, before it has left the hopper,
about one-half of all the gold or silver which it bears. This I accomplish, first
by providing the body of the stamp proper at such distance above the shoe and
below the top of the coffer as to encounter the least amount of friction and wear,
with a sleeve of copper or other suitable material provided on its exterior face
with a silver plating on which I produce an amalgam for the arrest of such portions
of the precious metals as are in proximity to the centre of the coffer. Second, by
providing in front of the screens through which the pulp finds its exit grilles or
slatted frames the slats of which are similarly provided on one or both sides with
silvered and amalgamed surfaces, and preferably adapted to swing or be agitated
by the impact of the material being crushed, to the end that a greater amount of
the precious metal and the amalgating surfaces are brought in contact with each
other and the particles of the rock caused to fall away and leave the collecting
surfaces and the screens unobstructed.
1 furthermore combine in the coffer of a double alternating stamp mill, two
anvils which are perfectly cylindrical, as distinguished from being square or having
angles, in consequence of which I obtain a more perfect circulation of the pulp,
both ground and partly ground, around said anvils and over their upper faces as
the stamps rise, with the final result that all of the material is more quickly and
finely ground to the desired degree of fineness.
I furthermore make these anvils flat upon their under side and reversible in the
coffer so as to work as well one side up, as the other side up, and enable them to be
inverted whenever the top surface is worn so as to render its grinding action
imperfeet.
It will ho undustood that the imusaumont, shows mentioned mon ho annlied to

page_text: other forms of stamp than the precise ones illustrated in the Sholl Patents, above
referred to. In the use of the Sholl machine however, I have encountered other
serious difficulties which I have obviated by improvements adapted especially to
pneumatic stamps of the character designed by Sholl or of some other analogous
construction. In the use of such pneumatic stamps in which the upper portion of
the stamp proper is formed with or attached to a pneumatic cylinder, a great
amount of sand or small pieces of rock are caused by the descent of the stamp to
fly upward along its sides and enter the ports of the pneumatic cylinder, and I have
found this to occur to such a degree as very soon to cut out the cylinder or the
piston and render the pneumatic action of the stamp exceedingly imperfect, and in
some instances, to entirely destroy it. According to my improvement in this part
of the machine, the cover of the coffer is provided, in addition to the usual plate
which surround the stamp, but which is inefficient to prevent the upward passage
of the small partieles of ore as aforesaid, with a supplemental flange or plate of
any suitable material. The particles of are which pass the main plate, I find, will
have their velocity so much impaired, or their direction of motion so changed that
they will not pass the second plate or supplemental flange. Such supplemental
plate may consist of a leather or rubber annulus bolted to the main plate of the
coffer cover and closely surrounding by its inner free edge, the body of the stamp,
or said supplemental flange may consist of a metallic web preferably east with the
main plate of the coffer cover and situated at a small distance above it, leaving
between it and the said main plate a space in which the particles driven upward by
the force of the blow of the stamp will collect, and from which they will fall back,
when they have accumulated in a sufficient amount, into the coffer. When the body
or shank of the stamp has by use, lost its true central position in the coffer and in
the space in the coffer cover through which it passes, such openings are left as to
permit the aforesaid objectionable passage of particles of ore to the pneumatic
cylinder, and to obviate this difficulty I have provided the stamp body with vertical
slide bearings in which are situated adjustable gibs adapted to be set up from either
side against the stamp in such manner as to bring it back to its accurate central
position.
My invention further consists in certain parts and combinations thereof, herein-
after particularly set forth and claimed.
In order to make my improvements more clearly understood, I have shown in
the terompanying drawings means for carrying them into practical effect, without
however,
the invention in its useful applications to the particular con-
struction which, for the sake of illustration, is delineated.
In said drawing——
Fig. 1 is a front view, one-half in elevation and the other half in section, of n
double pneumatic ore stamp embodying my improvements.
Fig. 2 is a transverse vertical sectional view of the same on line 2-2 Fig. 1, the
stamp proper and anvil being shown in elevation.
Fig. 3 is a plan view, the upper portion of the machine being removed, as well as
the side plates, and the top plates of the pneumatic cylinders being also shown
removed.
Fig. 4 is a plan view of the coffer and anvils, with the lower spray-pipe.
Fig. 5 is a plan view of the coffer cover provided with supplemental flanges of
flexible material surrounding the stamp openings.
Fig. 6 is a similar view of another form of coffer plate in which the supplemental
flange is formed integrally with said plate.
Fig. 7 is a sectional view of the same on line 7—7 Fig. 6.
Fig. 8 is a side view of the upper portion of one of the stamps, the said portion
constituting the pneumatic cylinder.
Fig. 9 is an elevation of one of the guides for said cylinder, provided with its
adjustable gib.
Figs 10, 11 and 12 illustrate by sectional and plan views the mode of applying
the split rings to the pneumatic cylinder.

page_text: Fig. 13 is a plan view partly in section of another form of shaft for actuating the
stamps, the shaft being made hollow and straight, and eccentrics being provided in
place of cranks, in order to facilitate transportation and repair in mountainous and
unfrequented districts.
Fig. 14 is a plan view of the main water supply pipe for the ore chutes.
Fig. 15 is a sectional view showing a portion of the coffer and one of the screens
together with the spray-pipe which operates to prevent banking of the material
against the screen.
Fig. 16 is a horizontal sectional view of the mill or stamp showing the coffer in
plan view, and in place therein between the anvils and the exit screens, the grilles
or slatted frames for arresting by their silvered or amalgamed surfaces metallic
particles of the orez.
Fig. 17 is a perspective view of one of said grilles removed.
Fig. 18 is a sectional view of a portion of one of the grilles showing the means
for separating and supporting its slats or bars.
Figs. 19, 20, 21 and 22 illustrate by perspective views other forms of grilles
embodying my improvements.
Fig. 23 is a plan view showing a portion of the coffer cover and a packing ring
or plate made in two or more portions adjustable towards or from the stamp proper
for the purpose of occluding the opening through which the stamp works and
preventing grit from being forced upwards out of the coffer and into the pneumatic
cylinder or cylinders.
Fig. 21 a vertical acctional view of the part shown in Figure 23.
Referring to the drawings 1 indicates a metallic base-plate adapted to be secured
upon any suitable foundation of wood, brick or stone and surrounding the coffer 3
adapted to hold the ore which is to be pulverized. The coffer is formed with two
cylindrical seats or recesses 4 (Figs. 1. 2 and 4) in which are mounted cylindrical
anvils similarly shaped upon the top and bottom and adapted to be inverted when
worn. These anvils are securely wedged in place by wooden packings 6. The
circular shape of each of the anvils permits the free circular movement of the ore
in the coffer and greatly promotes the rapidity of reduction.
7 indicates metallic side frames situated, one at each end of the coffer, mounted
on the base 1. and provided at their upper ends with bearings 8 in which is
mounted a crank or eccentric shaft 9 provided with suitable fly and belt wheels or
pulleys.
From the cranks of said shaft are suspended yokes 10, each of which carries at its
lower end a transverse pin 11 which fits in a bearing 12 formed in the pneumatic
piston 13. The latter is provided at each end with a peripheral rabbet 14 (Figs. 10
and 12) in which fits a split ring 15 of substantially the width of the rabbet and of
half the thickness of it. On the ring 15 are moanted two independent split-rings 16
which are adapted to fit tightly within the bore of the pneumatic cylinder 17.
Plates 18 bolted to each end of the pneumatic piston contine the said rings lon-ely
in place.
The cylinder 17 has a cover 19 on its upper end, slots 20 through which the
pin 11 passes, a bottom head or diaphragm, a lower hollow portion 22 provided
with an external cylindrical rabbet 23. and a bearing 24 in which fits the Shank 25
of a stamp shoe 26. Said shank is wedged in place by a wooden packing 27.
28 is a hollow cylindrical plate of copper fitting in the said rabbet 23 of the
stamp, supported by the shoe 26, and having a silvered surface on which may be
formed an amalgam for arresting the precious metals of the pulp at the centre of
the coffer
The coffer is enclosed at its sides by open frames 29 which are secured to the
frames 7. In each of the frames 7 and 29 fit screens 30 of reticulated material
which are held in place by removable frames 31. The latter are secured by
buttons 32. The said frames and screens form an inclosed space above the upper
edge of the coffer from which the ore-pulp works gradually through the reticulations
of the screens into any suitable exterior receptacle surrounding the base of the

page_text: machine and which forms no part of my present invention. The coffer is covered
by plates 33 formed with suitable openings for the stamps proper and with a
flange 34 surrounding said openings.
In order to prevent the escape from the coffer of sand and particles of ore which
have been of great injury to the pneumatic cylinder of such stamps, I surround the
said openings in the coffer cover with supplemental flanges 35 which may be
separate from the coffer cover, formed of soft material such as leather and secured
in place by bolts 36 as indicated in Fig. 5, or may be of iron cast integrally with
the cover as in Figs. 6 and 7 leaving between them and the main portion of the
cover spaces 37 in which mineral particles escaping from the coffer, will be
arrested. The flanges 35 shown in Fig. 5 are formed with slots 38 for the
bolts 36 and may be adjusted inwards to closely fit the body of the stamp as
occasion may require.
The stamps are properly guided in their vertical movement by ribs 39 (Fig. 3
and 8) which fit in guides 40 formed on the inner faces of plates 41, the latter
being bolted at 42 to the end frames 7. In order to provide for accurately
centering the stamps in the coffer and its cover gib 43 are placed between the
guides in position to engage the ribs 39. Said gibs are provided at their upper
ends with horizontal flanges 44 which are slotted to receive bolts 45 screwing into
the plates 41. Each gib is also engaged along its outer side by set-screws 46
which serve to set it up accurately against the ribs 39 of the stamp.
The ore is fed to the coffer by a chute 47 (Fig. 21 together with streams of
water from the pipes 48 controlled by a valve 49.
The pneumatic cylinder is prevented from becoming over heated by friction and
compression of the air by water spray-pipes 50.
The banking of ground and partly ground ore in the coffer against the inner
sides of the screens 30, which has been the great source of difficulty in the use of
ore stamps having such screens, 1 obviate by a spray pipe 51 (Figs. 2, 4 and 15)
having jet orifices adapted to direct streams of water into and upon the material in
such manner that the screens are always kept clear and ready for the passage of
such pulp as has been completely ground.
The crank shaft 9 as ordinatily made is very heavy and difficult of transportation.
It is also difficult to make or repair. I have provided for use with this ore stamp
an actuating shaft of improved form indiented in Fig. 13. This shaft is hollow and
straight with solid ends and is provided with actuating eccentries which are
separate from the shaft and may be attached thereto by any machinist or black-
smith, so that accidents may be repaired with much less trouble and cost than with
the ordinary form of crank shaft.
In order to collect and save a considerable portion of the gold or silver, or both,
within the coffer I provide silvered and amalgamed collecting plates or grilles
situated within the space enclosed by the screens 30 and across the path which the
pulp must take in finding its exit from the machine. These plates are indicated
at 52 and are secured upon vertical rods 53. They are preferably silvered on both
sides and reversible or invertible. They are pivotally suspended at 54 from ears 55
on the under side of the coffer cover or other suitable part of the frame of the
machine.
Said plates are also in proximity to the spray pipe 51 the streams from which
aid the agitation of the grilles in keeping them clear of undesirable material and
free to act to the best advantage in arresting the metallic particles of the ore.
Referring especially to Figs. 16 to 22 inclusive, I will now describe more in
detail several useful forms of the grilles hereinbefore referred to. In Fig. 18
the plates or slats 52, which are made of copper or other suitable metal silvered
and coated with mercury or amalgam, are spaced from each other by thimbles 56
through which, as well as through the plates the rods 3 pass."
Said plates
preferably incline inwards towards the middle of the coffer so as to throw back any
particles of ore which are not sufficiently reduced. This inclination effect by
bevelling the ends of said thimbles which engage the plates, as best seen in Fig. 18.

page_text: On the ends of the rods 33 are screwed eyes 57 which are adapted to be engaged
by horizontal rods 58. The latter are supported in the ears 55 already referred
to. By removing said rods the grilles may be inverted so that the bottom as well
as the top surfaces of the plates may be fully utilized for the collection of the
particles of metals from the ore. When said plates have collected as much of said
metal as they are capable of holding they are removed, fresh grilles being at the
same time substituted, and the plates cleaned either with or without taking
the grilles apart as may be found most expedient. Very little time is thus lost
in the operation of the stamp mill, and a considerable percentage of the gold
and silver is recovered from the ore or pulp produced by the mill without
further treatment of said putp. The pulverized material which issues from the
coffer through the screens is collected and treated in the proper manner, which
latter does not relate to my present invention, for the recovery of the remaining
metal.
In Fig. 19 the plates 52 are shown as individually removable from and
reversible in the grilles for which purpose the latter have side bars 69 provided
with projections 59. On the latter rest the plates 52 which engage by their
notched ends the said side bars. In this construction said bars have formed in
their ends eyes 60 through which the rods 58 can be passed, and are held together
by tie rods 61.
In Fig. 22 the plates are mounted in the side bars by end pivots 62 and are
adjustable as to their inclination by a rod 63, the screw threaded end of which
passes through an arm 64 attached to one of the side bars. The rod 63 is pivotally
connected with the plates 52 as shown in said figure, and is adjustable up and
down by nuts 65 which fit on its screw threaded end and engage the top and
bottom side of the arma 61. I can thus give that angle to the plates which is
best for the efficient collection of the metallic particles and for throwing back the
unreduced pieces of ore.
In Fig. 20 the slats are arranged in vertical position. In Fig. 21 they are
arranged as already described with reference to Figs. 17 and 18, but are corrugated
so as to better arrest and collect the metallic particles.
It will be understood that the grilles are suspended so as to be capable of being
agitated by the impact of the pieces of ore flying from the stamp, thus aiding in
bringing the particles of metals in contact with the amalgamated surfaces of the
plates and causing unreduced pieces of ore to roll back into the coffer.
Referring to Figs. 23 and 24, 66 indicates a metallic ring which is made in two
or more parts as shown, and mounted upon the coffer cover 33 around the opening
through which the stamp proper descends. The parts of these rings or plates are
adjustable towards and from the stamp, being slotted as shown at 67 to receive
their clamping bolts 68. I am thus enabled always to keep tightly closed the
openings through which the stamps work, adjusting the parts of the rings toward
the stamps as fast as any wear takes place, in a manner that will be obvious upon
an inspection of said Figs. 23 and 24.
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. An ore stamp or mill when constructed as follows:-namely, when containing
the combination with the coffer, and the upright screens which surround the coffer
in immediate proximity to the stamp for regulating the passage of the ore-pulp
from the coffer, of a pipe having spray orifices directed towards the bases of said
screens and adapted to keep the latter clear and ready for the passage of the pulp
by washing the material which will not pass the screens back into the coffer and
thereby preventing said material from banking against the screens, substantially as
set forth.
2. The combination with the coffer, and screens for regulating the passage of
the ore-pulp therefrom of a spray pipe within the cofler and adapted to act on the

page_text: material banked against the screens and keep said screens clear and ready for the
passage of the pulp, substantially as set forth.
3. The combination in an ore stamp, with the coffer, and screens 30, of the spray
pipe 51 situated within the ore receptacle at the base of said screens, substantially
as set forth.
4. The combination with the stamp proper, of a sleeve having an amalgamated
surface and mounted on the stamp above the shoe, substantially as set forth.
5. The combination with the stamp proper having the recess or rabbet 23, of
the amalgamated plate or sleeve 28 and the shoe 26, substantially as set forth.
6. The combination with the coffer and the stamp proper, of a pneumatic
cylinder and piston connected with the upper end of the stamp, a coffer cover
surrounding the stamp, and a supplemental flange on said cover and around the
stamp and adjustable on said cover towards the stamp and operating to prevent
particles of ore from the cuffer from passing upwards at the sides of the stamp to
said pneumatic devices, substantially as set forth,
7. The combination in an ore stamp with the coffer and the stamp proper, of the
coffer cover surrounding the stamp, guides for the latter, and adjustable gibs 43 în
said guides having the slotted flanges 44 and bolts 15, substantially as set forth.
5. The combination of a pneumatic cylinder and piston connected with the
stamp proper, said piston being provided with anunlar rabbets or grooves, and a
plurality of split metallic rings scatel in said grooves, one re ting on the other,
substantially as set forth.
9. The amalgamated plates 52 combined with the coffer and the screens 30
and situated within the space enclosed by said screens and in the path of the pulp
as it passes to and through said screens, and the spray pipe 51 in proximity to
said screens and plates, and adapted to clear the same, substantially
as set forth.
10. In an ore stamping or pulverizing mill, the combination with the coffer or
stamping chamber having a discharge opening, of a grille having amalgamed
surfaces and removably fastened within said coffer at such point as will be in the
path of the pulverized material as it is discharged, so as to intercept the metallic
particles, substantially as set forth.
11. In an ore stamping machine or mill, a grille formed of a series of amalgn-
mating plates supported in front of, or near the discharge opening of the coffer
so BS to move or vibrate under the impact of the material which is stamped,
substantially as set forth.
12. The amalgamating grille or grating hereindescribed consisting of a series of
parallel inclined plates, and supporting rods whereby the same may be suspended
from either end, substantially as set forth.
13. An amalgamating grille or grating, consisting of a series of plates 52
having notched ends, and side bars 69 having projections for supporting the plates,
substantially as set forth.
14. The improvements in machinery for stamping ore when constructed as shown
in the accompanying drawings.
15. The improvements in machinery for collecting metallic particles in the
coffer of an ore stamp or mill when constructed as shown in the accompanying
drawings.
Dated this 20th March 1803
J. W. MARSHALL,
Per W. H. Beck,
Agent.