Improvements in the Manufacture of Iron Plates or Grids used in connection with Ore Grinding Mills, applicable also to other purposes.
Year: 1893

page_text: Date of Application, 18th Apr., 1893
Complete Specification Left, 16th Jan., 1894-Accepted, 3rd Mar., 1894
PROVISIONAL DILUIFICATION.
Improvements in the Manufacture of Iron Plates or Grids used in
connection with Ore Grinding Mills, applicable also to other
purposes.
I, ROUGHSEDGE WALLWORK, of the Firm of Henry Wallwork & Company of
Union Bridge Iron Works, Charter Street, Manchester, in the County of
Lancaster, Engineers and Ironfounders, do hereby declare the nature of this
invention to be as follows:-
My improvement relates more particularly to the plates or grids used in
connection with ore grinding mills. These grids are arranged at the bottom of a
grinding mill and have arranged in them a series of fine slots radiating from the
centre. It is necessary that these slots should be very fine and also at the same
time very clear. The material being ground passes through these slots which
regulate the degree of fineness of the material ground. These slots as at present
made very soon get too large and are useless being made with sand cores and
having to have much taper so that the sand will leave the pattern.
In my improved method of making these plates I use for the purpose of making
the fine slots thin steel plates or chills which I ram up in the mould with the sand.
By means of these steel plates or chills I get not only a hard wearing surface, but
I also get a certain amount of parallel slots that will resist the wear much longer
than those now in use which have to come up to a fine edge so that the sand will
leave the mould.
The arrangement described above is applicable to other purposes where very fine
slots or holes are required.
Dated this 17th day of April 1893.
ROUGHSEDGE WALLWORK.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Iron Plates or Grids used in
connection with Ore Grinding Mills, applicable also to other
purposes.
I, ROUGHSEDGE WALLWORK of the Firm of Henry Wallwork & Company, of
Union Bridge Iron Works, Charter Street, Manchester, in the County of
Lancaster, Engineers and Ironfounders, 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:-
My improvements are in connection with what are known as mill grids, that is,
a series of sections of grids used in connection with grinding mills or machines
used in grinding coarse material to finer quality for various purposes. So that the
same may be better understood I have made one sheet of drawings to which I
refer.
Figures 1, 2, 3 and 4 show a portion of one of the mill grids as made in the usual
way. A. A. A. Figure 1 shows the slots referred to in plan. Figure 2 shows the
section of plate, and the angle B. B. is as the patterns are usually made so that
they will leave the sand in moulding, and resist the metal in the moulds. It will
at once be seen that upon the plates becoming worn, even very little, the slots A. A.

page_text: Figure 1 become very wide and consequently useless as shown in Figure 3 in plan
and Figure 4 in section.
The dotted line shown in Figure 4 shows amount worn off plate and size of slots
when this amount is worn off. Figures 5. 6 7 and 8 show grid made by my
improved method. Figure 5 shows plan of slots, and Figure 6 shows same in
section made by my improved method, and shows clearly my arrangement for
making. C. C. shows section of metal of grids. D shows one of chills in position
supported in the mould by the saud E. E. In making 1 place all the necessary
chills in the pattern and then mould in the usual manner. After drawing the
pattern I coat the part of the chills that come in contact with the metal with oil,
as is usually done in regular chilled work.
It will be seen, as shown in Figure 6, that the slots have very little taper and
are shown very fine. In some cases more taper is required to allow for more
clearance for material ground, but it will at once be seen that grids made by my
In Figures 7
method will wear for some time without the slots getting too wide.
and 8 I show two views of chills in general use. In Figure 7 the ends of the slots
are taper, and when casting contracts the chill is forced out. In Figure 8 I show
chill as used when the ends of the slots are required square. In cases where finer
slots are required than is shown in Figures 5 and 6 1 cut out pieces of sheet
asbestos of the desired shape and then press them to put upon them the smooth
surface necessary, and after baking them to make them hard use these as chills.
The objection to these is that it is very seldom I can use them over again, as is the
case with metal ones, and metal ones have also another important advantage, that
is, that when the molten metal comes in contact with the metal surface that is to
form the slot it is chilled or hardened, and this prevents them wearing so rapidly.
Another application of my improved method is in connection with gas stoves or
burners. In these stoves a fine slot is in some cases a great advantage. I show
upon sheet of drawings one example, part in plan and section, see Figures 9
and 10. I do not confine myself that these chills shall be in all cases straight, as
shown; they may be curved as required for any special purposes.
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
1st. The casting of grinding mill grids in which fine slots are required by means
of chills as shown, these chills being of metal.
2nd. The casting of grinding mill grids in which fine slots are required
by means of chills, as shown, these chills being composed of a thin, hard core such
as a metal strip.
3rd. The casting of gas stove burners with fine slots by means of chills as shown,
these chills being formed of a thin, hard core such as a metal strip.*
Dated this 15th day of January 1894.
ROUGHSEDGE WALLWORK.