Improvements in the Manufacture of Steel and other Metal Castings.
Year: 1892

page_text: Date of Application, 23rd May, 1892
Complete Specification Left, 23rd Feb., 1893--Accepted, 29th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Steel and other Metal
Castings.
1, WILLIAM ELLIS MAY, of 19, Haydon Park Road, Wimbledon, in the
County of Surrey, Civil Engineer and Naval Architect, do hereby declare the
nature of this invention to be as follows:-
My invention relates to the manufacture of steel and other metal castings.
According to my invention the molten metal is poured into the mould in vacuo,
the vacuum being preferably produced in the manner described in the Specification
of former Letters Patent granted to me No. 4549 of 1891.
After the metal is poured and whilst still in a molten condition it is subjected
to pressure in the mould either by means of a piston or ram or by any other
suitable means, whereby it is thoroughly compacted.
By means of my invention I am enabled to obtain castings extremely homogeneous
and free from blow-holes, the air and occluded gases being removed prior to the
action of the pressure upon the metal.
31
ስለ
1000
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Steel and other Metal
Castings.
I, WILLIAM ELLIS MAY, of 19, Haydon Park Road, Wimbledon, in the County
of Surrey, Civil Engineer and Naval Architect, 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 invention relates to the manufacture of steel and other metal castings.
According to my invention the molten metal is poured into the mould in vacuo,
the vacuum being preferably produced in the manner described in the Specification
of former Letters Patent granted to me No. 4549 of 1891.
After the metal is poured and whilst still in a molten condition it is subjected to
pressure in the mould either by means of a piston or ram or by any other suitable
means, whereby it is thoroughly compacted.
. By means of my invention I am enabled to obtain castings extremely homogeneous
and free from blow-holes, the air and occluded gases being removed prior to the
action of the pressure upon the metal.
To enable my invention to be fully understood I will describe the same by
reference to the accompanying drawings, in which :—
Figure 1 is a sectional elevation of an arrangement of plant suitable for carrying
out my invention; and,
Figures 2, 3, 4, 5, 6, 7 and 8 are views of details of the same hereinafter
described.
a is a mould which as shewn in the drawings is represented as for a gun,
and 6 is the lining of a pit in which the said mould is placed. c is an outer
casing which is placed around the lining b, and the space between which and the
aid lining is advantageously filled with concrete, such concrete filling serving to
upport the lining against the internal pressure due to the filling of the mould
[Prine 877

page_text: with metal and to the external pressure due to the formation of a vacuum within
the said lining in the manner described in the Specification of my Patent before
referred to.
d is a chamber which is placed over the mould and from which the air is
exhausted prior to the pouring of the metal, and e is the supplementary chamber
into which the molten metal is first poured and from which it is conducted to
the bottom of the mould through the channel or open runner f, the funnel or
hopper g and the runner h.
Figures 2, 3 and 4 shew an elevation, vertical section and horizontal section
respectively drawn to an enlarged scale of a sliding door between the
supplementary chamber e and the runner f, the lifting of which door allows the
metal to flow into the mould. j is a block of refractory material carried in the said
door i and serving to immediately close the opening from the chamber e.
k is a hydraulic ram arranged in a cylinder / below the bottom of the mould (1,
and m is a block of wood or other suitable material placed upon the top of the
said ram and serving to prevent the molten metal from coming into contact with
the said ram and so causing the expansion of the same and the heating of the
water in contact therewith. n, n' are two accumulator rams, and 0, o' the cylinders
in which they respectively work, the said cylinders being connected by the pipe p
to the underside of the ram k. At the bases of the cylinders o, o' are valves q, g¹
by means of which the communication between the said cylinders o; o and the
pipe p is controlled. The weights r, r for the rams n, n' respectively are carried
upon pistons s, s' respectively, the said pistons sliding in cylinders t, t¹. u, u' are
the pipes through which the water is forced into the cylinders t, t' for lifting the
rams with their weights, and v, v are pipes through which the water beneath the
pistons s,
may be allowed to escape to regulate the pressure exerted by the rams.
In practice the two rams' n, n¹ are made of different areas or otherwise so
arranged that as the metal in the mould solidifies greater pressure may be placed
upon the same.
In using the apparatus hereinbefore described, the air is first exhausted from the
mould and the. chamber above the same, for instance in the manner described in
the Specification of my said former Patent. No. 4549 of 1891, the molten metal is
then introduced into the chamber e and from thence allowed to flow into the
mould by lifting the door or valve : when the mould is filled the discharge
valve g of the accumulator ram n is opened and the said ram allowed to descend
whereby the ram k is gradually raised and compresses the metal in the mould.
When the accumulator ram n reaches the limit of its downward movement the
valve g is closed and the valve q' beneath the ram n" is opened, whereby this ram
commences to exert its pressure upon the ram k, which pressure will be greater
than that exerted by the ram n for the reason that the said ram n¹ is of smaller
area than, and weighted to the same extent as, the ram'n.
As fresh metal cannot be introduced after the mould has once filled it is
necessary that sufficient metal' should be provided above the ram so that when the
mould is sufficiently compressed the said ram is not forced into the casting proper.
In order that the pressure exerted by the ram k shall not lift the mould off its
seat, the cylinder of the said ram kis mounted upon a base plate w forming the
hottom of the pit and connected by strong tie-bolts w', w to other plates, on
the top of the mould. These plates x and x are represented in plan in Figures 5
and 6 respectively. The plate has in it a valve y (as shewn in Figure 1 and in
Figure 7, which latter figure is a plan view of the mould) through which any gases
exhausted from the metal by the vacuum may escape into the chamber d above the
mould. The plate which is preferably of wrought iron or steel serves for
strengthening the plate x and has in it a hand hole for permitting the valve to
be adjusted.
To resist the lateral pressure upon the sides of the mould a I provide stays z, z
between the latter and the lining b, as shewn in Figure 1 and in Figure 8, which is
a sention on the 1: 0 0 T

page_text: 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. The improvement in the manufacture of steel and other metal castings
consisting in introducing the molten metal into moulds in vacuo and then subjecting
such metal to pressure, substantially as described.
2. The manufacture of steel and other metal castings by means of apparatus
constructed and arranged substantially in the manner hereinbefore described and
illustrated in the accompanying drawings, and operating as, and for the purposes,
set forth.
Dated this 23rd day of February 1893.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.