An Improved Method of Casting Headers on Rolls, Shafts, and other Castings Requiring to be Cast Vertically.
Year: 1899

page_text: Date of Application, 23rd, Oct., 1899-Accepted, 23rd Dec., 1899
COMPLETE SPECIFICATION.
An Improved Method of Casting Headers on Rolls, Shafts, and other
Castings Requiring to be Cast Vertically.
We, ROBERT BROWNE TENNENT and JOHN TENNENT, both of Whifflet Foundry,
Coatbridge, Lanarkshire, Iron Founders, 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 an improved method of casting headers on rolls, shafts,
and other castings requiring to be cast vertically.
At present, when casting rolls for rolling metals and other purposes by the
usual method a receiver is cast at the top end of the casting with the object of
feeding the body of the roll with metal as it solidifies and also of insuring the
solidity of the finished roll. It is usual to make this receiver of a somewhat
larger diameter than the diameter of the "wabbler" end of the roll and also of
the same diameter throughout its length. This method is found to possess dis-
advantages in so far that the exposed surface of the receiver solidifies to such
an extent as to check the proper flow of metal to the upper end of the roll with
the result that this end of the casting is more or less soft and spongy.
Our invention has for its object to so cast the metal that the top end of the
casting will be as hard and solid as the body of the casting.
In order that our said invention may be properly understood we have hereunto
appended an explanatory sheet of drawings, whereon,
Fig. 1 is a view of a roll as cast in accordance to our improved method.
Fig. 2 is a view of the bottom end of the roll.
Fig. 3 is a view of a roll cast in a slightly different manner.
Fig. 4 is a view of another roll cast in a slightly different manner.
Fig. 5 is a view of the upper end of a roll as cast in the ordinary manner.
On referring to Fig. 5 it will be seen that the upper end a¹ of the casting has
a receiver above it which is of the same diameter throughout and is of a some-
what larger diameter than the diameter of the part a¹. The receiver has to be
made large enough to supply the body of the roll with metal. The large exposed
surface c of the receiver tends to cool rapidly and solidify with the result that the
proper flow of metal to the top end of the casting is checked thereby causing this
end to suffer in strength. This is proved by the fact that the work of cutting off
the receiver, along the line A, A, is comparatively easy as well as by our experience
in working with rolls cast in this manner.
Now, in carrying out our invention we make the receiver, Fig. 1, of sufficient
dimensions to supply the proper quantity of metal to the roll in order to ensure
its solidity at the upper end and, instead of carrying it straight up as at Fig. 5;
we contract it at the upper end at d, to, preferably, the same or about the same
diameter as the diameter of the "wabbler" a¹. This contraction of the receiver
at its upper end is a matter of great importance as we find that the air only acting
on the narrow part d does not in any way interfere with the proper feeding of
metal from the receiver b¹ to the upper end of the casting with the result that this
end of the casting is cast equally solid with the body. This we have proved when

page_text: cutting off the receiver, along the line B-B, as we find that the metal is so hard
and solid that the work of cutting is a comparatively difficult one and that
specially sharp and hard steel tools have to be used.
Instead of making the receiver of the bulb form with narrow neck d, as shown
at Fig. 1, it may be made of a conic form as shown at 62 Fig. 3 or a partly cylin-
drical and partly conic form as shown at 63 Fig. 4. In both Figs. 3 and 4 it will
be seen that the upper end of the receiver has a narrow neck d.
Whilst the receiver itself may be made of any suitable shape, consistent with
the proper dimensions to ensure the desired solidity of the casting, it must have
a narrow upper end so as to preclude the possibility of the solidification of the
metal at that end interfering with the proper feeding of the molten metal to the
casting.
The invention can be applied generally when casting heavy castings in a vertical
mould.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we consider novel and desire to claim is :-
The method of casting metals in vertical moulds wherein a receiver is used of
sufficient capacity to ensure a proper flow of metal to the body of the casting and
which is reduced or tapered at its upper end so as to preclude the possibility of
the solidification of the metal at that end interfering with the proper feeding of
the molten metal to the casting, substantially as set forth.
Dated this 21st day of October 1899.
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.