Improvements in Stamps for Crushing Gold and other Ores.
Year: 1897

page_text: his Print is in accordance with the Original Specification as it stands after
further Amendment (under Section 18 of the Patents, &c. Act, 1883) as
allowed by the decision of the Comptroller General of the 15th day of
Juno 1898
Date of Application, 20th Mar., 1897-Accepted, 21st Aug., 1897
COMPLETE SPECIFICATION (AMENDED).
Improvements in Stamps for Crushing Gold and other Ores.
I, FREDERICK ALEXANDER PARNELL, of 10, New Broad Street, in the City and
County of London, Mechanical 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 : -
This invention relates to improvements in the machinery for, and the method
of, crushing gold and other ores and has for its object the provision of means
whereby the weight of and space occupied by such machinery and the power
required to drive the same may each and all be greatly reduced while concurrently
the ore to be treated is more rapidly and efficiently pulverised to the required
grade of fineness, a further advantage being that the machinery is so constructed
as to allow of part of the plant being detached and used as a rock drill if so
required.
In carrying my invention into effect I employ a light metallic framework,
preferably of steel and approximately of the form hereinafter shown and described.
On the base of this frame is suitably secured the stamp box, or boxes, and also the
necessary uprights and cross beam, for carrying the superstructure to which the
stamp actuating mechanism is attached. This mechanism consists of a number of
steam cylinders placed vertically one above each stamp head. Each cylinder is
provided with a piston and valve of the type hereinafter described and in each
case the piston rod is attached to its appropriate stamp spindle by a taper coupling
clip the upper half of which is fixed to, by being constructed on, the piston rod,
while the lower half, tapered to suit the correspondingly tapered head of the
stamp spindle, is provided with a cottar hole and cottar to allow of the stamp head
and its spindle being readily disconnected and replaced by a drill bit when required
for drilling. The piston and cylinder are relatively so arranged and constructed
that the piston not only has a reciprocating motion but also a motion of partial
rotation imparted to it, which being communicated to the stamp head adds greatly
to the effectiveness of its blow by causing it to grind as well as pulverise the ore
under treatment.
The action of the piston is such also as to cause and control the working of the
valve by the live steam thus ensuring a positive working of the valve without the
aid of any extraneous gearing and an equally positive action of the stamp but I
make no claim to this arrangement as it is fully described and shown in connec-
tion with rock drills in the former Specification of Ernest de Pass, No. 629 of the
year 1878.
Taking the ordinary three stamp plant as a typical illustration I will describe

page_text: one complete element thereof in reference to the drawings in which Fig. 1 is an
end elevation; Fig. 2 is a part longitudinal section on centre line and part eleva-
tion of a piston showing internal rifled nut Fig. 3 is a section through piston
valve and chest; Fig. 4 is a cross section through centre of same Fig. 5 is a cross
section of piston valve showing improved arrangement of semi-ring; and Fig. 6
is a section of cylinder, piston-valve and chest showing steam ports. It will
be seen from Figure 1, that in constructing a high speed percussive and par-
tially rotary stamp in accordance with this my invention a suitably constructed
base A has secured to it the stamp box B and the upright framework C, C,
carrying the cross beam D. The upright C also carries the steam or other fluid
pressure supply pipe E and the exhaust pipe F, while the beam D serves to carry,
and has secured to it, in this case, three of the cylinders G. Each cylinder is
provided with a valve box H, connected by suitable couplings and pipes P. P. as
shown to the supply and exhaust pipes E and F, and containing the valve V
described hereafter with reference to Figures 3 and 4. The piston rods R are
united at their top ends to the pistons, one of which is shown in detail in Figure 2,
and at their lower ends to the stamp spindles S by means of the clip couplings I
and cottars J in the manner herein before referred to, the stamp heads K being
approximately of the form shown, or they may be of any other suitable
configuration.
The piston L, Figure 2, is provided with four packing rings, of the Ramsbottom
type at a, a, a, a, and a rifled nut at 6 and this working on a rifled bar attached
to the top cylinder cover causes a partial rotary movement to be imparted to the
piston and in turn to the stamp head K, on both the upward and downward
strokes.
In other respects than those mentioned the construction and action of this piston
are substantially the same as described in my previous Letters Patent dated the
28th day of July 1891 and numbered 12,793.
In this previous Specification I also illustrated, described and claimed a method
of packing the upper halves of the piston ends ZZ of valves of the type shown
in Fig. 3 at V. I have since then found that the semi-circular packing rings m
wear at the lower parts d, d, (see Fig. 5) to such an extent as to prevent them
springing up the crown of the ring, and to overcome this defect I now place under
the crown of the ring a small spiral spring f which by pressing up the crown
of the ring ensures an all round tight joint.
In a previous Specification of Letters Patent granted to Ernest de Pass, dated
February 14th, 1878, and numbered 629, it was shown how valves of the type
herein represented were actuated and I make no claim in this Specification to the
mode of actuating the valve.
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:-
First. The improved high speed percussive and partially rotary ore crushing
stamps constructed substantially as herein before shown and described.
Dated this 20th day of March 1897.