Improvements in or connected with the Manufacture or Production of Balls such as are used in Ball Mills for Grinding Ores or other substances.
Year: 1891

page_text: Date of Application, 12th Feb., 1891
Complete Specification Left, 3rd Dec., 1891-Accepted, 6th Feb., 1892
PROVISIONAL SPECIFICATION.
Improvements in or connected with the Manufacture or Production
of Balls such as are used in Ball Mills for Grinding Ores or other
substances.
I MIDDLETON CRAWFORD of 25 Eccles Road Clapham Junction in the County
of Surrey Engineer do hereby declare the nature of this invention to be as
follows:-
The balls which are used in ball mills are exceedingly heavy and consequently
are costly as regards carriage from place to place. Moreover when they become
worn there is considerable waste of material as they have to be entirely replaced.
The principal object of my invention is to overcome these objections. According
to my invention I make the balls of a hard outer part preferably employing a good
quality of hard steel for the purpose. This hard part is made hollow and constitutes
the ball proper or outer surface which performs the work of grinding. This hard
outer part is provided with means whereby its interior can be filled with heavy
material. I preferably employ for this purpose lead which can be melted and
poured into the interior of the hard outer part through an orifice or orifices therein
and when the outer part has become worn and has to be renewed the lead can be
removed by being melted and poured out and used to fill a new outer part. The
orifice or orifices may be provided with any suitable plugs or filling pieces for
closing them. By the foregoing arrangement I am able to save much cost in
carriage as the comparatively light hard outer parts can be sent to the place where
the balls are to be used and be there filled with the lead or other filling. I also save
material as the filling can be used over and over again.
Dated this 12th day of February 1891.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London.
COMPLETE SPECIFICATION.
Improvements in or connected with the Manufacture or Production
of Balls such as are used in Ball Mills for Grinding Ores or other
substances.
I MIDDLETON CRAWFORD of 25 Eccles Road Clapham Junction in the County
of Surrey 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 :-
The balls which are used in ball mills are exceedingly heavy and consequently
are costly as regards carriage from place to place. Moreover when they become
worn there is considerable waste of material as they have to be entirely replaced.
The principal object of my invention is to overcome these objections. According
to my invention I make the balls of a hard outer part preferably employing a good
quality of hard steel for the purpose. This hard part is made hollow and constitutes
the ball proper, or outer surface which performs the work of grinding. This hard
outer part is provided with means whereby its interior can be filled with heavy
material. I preferably employ for this purpose lead which can be melted and
poured into the interior of the hard outer part through an orifice, or orifices therein
and when the outer part has become worn and has to be renewed the lead can be
removed by being melted and poured out and used to fill a new outer part. The
orifice or orifices, may be provided with any suitable plugs or filling pieces for
[Price 8d.1

page_text: closing them. By the foregoing arrangement I am able to save much cost in
carriage as the comparatively light and hard outer parts can be sent to the place
where the balls are to be used and be there filled with the lead, or other filling. I
also save material as the filling can be used over and over again.
The accompanying drawings shew sections of balls made according to my invention
to illustrate the best means with which I am acquainted for carrying my invention
into effect.
In Figure 1 the ball A is cast hollow with a hole a in it and in this is cast the
malleable iron piece which fuses with the metal of the ball A so as to become
part of the shell but it is soft enough to be drilled and tapped. The material C
with which the hollow ball A is filled is then run in and then a screwed plug d is
inserted into the tapped hole in the piece and finished off to the sphere of
the ball.
In Figure 2 the hollow ball is cast with a hole a preferably tapering as shewn
but without the piece b. A steel plug d is introduced into this hole whilst the
interior filling C is molten and when it sets it holds the plug firmly in place by
reason of the inner part of the plug being grooved as shewn.
In Figure 3 two holes a² a³ are cast which preferably taper outwards as shewn.
A bolt having a head filling the hole a² is put in place the shank being smaller
than the hole a³ and entering it as shewn by the dotted lines. The filling material
is then introduced through the hole a³ and then a tapered steel collar e is introduced
and the small end of the bolt 3 is rivetted over as shewn in full lines.
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. A ball, for ball mills, consisting of an outer part of hard material to be filled
with a heavy, but softer material, substantially as hereinbefore described.
2. A ball, for ball mills, consisting of an outer part of hard material and having
an orifice, or orifices, into which molten metal is poured; the said orifice or orifices,
being then closed, substantially as hereinbefore described.
3. The several constructions of hollow balls filled and closed as hereinbefore
described and respectively illustrated in the several figures of the accompanying
drawings.
Dated this 3rd day of December 1891.
J. H. JOHNSON & Co.,
Agents.