The Arizona sentinel., 1879-09-06
x.u Form OF stamp Mill.

tbar,es 8 stanchaeld, of Oakland Cai''
has recently patented an ore mill OF ne"
- 7, consists 10 forming on hollow
shaft, journaled'to one side OIL 'ne 'en'''
=, ON evolute or eccentric case or MORTAR
series of hollow guides, properly ousneo
and lined. in each of which plays loosely
stomn. which strikes blow as the shalt
ia rotated. These guides being attached
to the shaft at right angles andthe stamps
PLAYING loosely in them, the stamps are
free to move out of the guides from either
end and can strike two blows for each
revolution of the shaft.
The mortar being made OF an eVolute
or eccentric form, after the stamps strike
their blow they slide up the incline or
curve, grinding or pulverizing the ore as
they move, until they reach suitable ribs
which free the stamps from any rock that
NAV have been carried up in the outward
movement. At this point gravity begins
to act and the stamp falls the other way
and crushes the ore, said operation being
repeated. Water is fed to the mortar
,hrough the hollow shaft and guides,
thereby iubricatiug the stamp stems ana
Keeping them free from grit.
The dies are made of curved plates
which are removable. As many stamps
may be placed in the shaft as practicable,
and they are set so as to hare regular
interval between the drop. As the stamps
slide freely on the ga des, when the shaft
is rotated at proper speed said stamps
slide or drop consecutively on the ore
lust as 1t reaches the dies under the feed
ening. This crushes The ore, and as
the stamps are eari led around by the ro-
talion Of the snaft, the shoes slide along
The dies and further pulyerize Or grind the
pre-. The mortar Or case being made III
a
neing iournaled at one side Of t1e center,
as each stamp slides along on the dies it
| gradually curves fal ther out of the guides,
centrifugal force kee ying it in close con
..,ct with the ore on the lies. Bef're The
alne, .owever, thai it reachss horizon
sal Dositon. the pressure gradually de-
lreuses .aud tue shoe slides of the dies on
( 90 a rib. A. The stamp slides on 10 this
my ore which may have accumulated on
h, shoe will faH back on to the dies
again.
The instant the stamp passes horizon
IL! position, gravitalion will cause it to
slide or drop in the other direction and
| out of the other end of the guide, giving
another blow upon the quartz on the dies
Each stamp therefore, strikes two blows
| for each revolution of the stamp.
The water admitted to the hollow shaft
is elected through the guides around the
stamp, going first out of one end of the
guide and then out of the other, as each
ead is pointed downward. This action
not only furnishes water to the battery
but also serves to lubricate the stamr
stem, and wash off any grift or sand from
the stamp. The steel bushing inside
the guide, and in which the stamp slides
is made removable, 80 ss to be changed
when worn.
! The rotation of the shaft is intended Il
be rapid enough to carry the stamps al
most to a vertical line before they strike
7 their blows, and each blow will therefore
be struck ct the point where ore drops OF
> the dies. The grinding action OF tn
stamp as it moves over the dies is tn
same as that of the drag of an arastra
which pulverlzes the ore after the frs
crushing blow; much the same as that Q
an ordinary stamp.
The shaft is mounted on adjustabl
journals SO as to regulate the amount c
drop to the stamps. In case Of dry crush
ing blast OF air may be forced throug
he hollow shaft instead of water, and lh
grit kept out Of the bushing by tha
means.-Chicago Mining Re0iew
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