IMPROVEMENTS IN STAMPERS FOR CRUSHING AND PULVERIZING ORES
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by John Warran and Thomas
Atkinson Ellis at the Office of the Commissioners of Patents, with
their Petition, on the 14th May 1875.
We, JOHN WARRAN, of Tavistock, in the County of Devon, Engineer,
and THOMAS ATKINSON ELLIS, of Pentonville, in the County of
Middlesex, Civil Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN STAMPERS FOR CRUSHING AND PULVERIZING
ORES," to be as follows, that is to say :—
This Invention relates to improvements in the arrangement and con-
struction of the cylinders and valves of stampers for crushing and
pulverizing ores, where such stampers are worked in pairs and driven by'
steam or other fluid pressure. By these improvements one valve only is
required to work a pair of stampers, great saving in the cost of con-
struction is effected, and a greater amount of work is obtained with a
less consumption of fuel than hitherto.
The Invention also relates to an improvement in the construction of
the coffers of stampers.
In carrying out our improvements we employ a pair of double acting
cylinders, preferably cast in one piece, the inlet and exhaust ports of

page_text: such pair of cylinders opening into or being in communication with a
cylindrical valve casing, suitably placed between the cylinders, or on a
line between the cylinders; in this valve casing which is placed (like
the cylinders) vertically, works a cylindrical valve, the rod of which
extends downwards, and is provided near its lower end with two arms or
tappets; the piston rod of each stamper is provided with a cam or
striker for striking the said tappets, so as to communicate a slight
circular or rotary motion to the cylindrical valve for reversing the same,
as herein-after described. The said valve is made slightly conical so as
to allow of its being adjusted as it wears by means of a pair of jam nuts.
By these improvements, when one stamper is rising, its cam or striker
coming against one of the arms or tappets on the valve rod, will move
the same and thereby the valve through a portion of a revolution, so as
to cut off the steam from the upper inlet port of the cylinder of the
descending stamper, and open the upper inlet port of the cylinder of the
ascending stamper, at the same time opening the lower and upper
exhaust ports respectively; the motion of the stampers will thus be
reversed and these movements will be continued, each stamper alternately
in ascending reversing the motion of the valve, it being understood that
the valve is so arranged that the full blow shall be given by each
´stamper before its motion is reversed.
In some cases we make the cylinders compound by enlarging the
diameters of the piston rods.
Our improvement in the coffers of stampers consists in casting or
fixing a casing on the inside of the coffer inclining towards the centre,
only sufficient space being left between the lower edge of such casing
and the stamper heads, as to allow of free working. The object of this
improvement is to prevent the escape of the slime or other portions of
the contents of the coffer from the lower part of the coffer into the
upper part above the stamper heads. This casing will also assist in
discharging the pulverized mineral through the gratings.
· This improvement is applicable to the coffers of stampers at present
constructed