Improvements in and connected with Moulds for Casting Metals.
Year: 1895

page_text: Date of Application, 21st Nov., 1895
Complete Specification Left, 11th Mar., 1896-Accepted, 14th Nov., 1896
PROVISIONAL SPECIFICATION.
[Communicated from abroad by LOUIS J. CRECELIUS, of St. Louis, Mo., U.S.A.,
Engineer.]
Improvements in and connected with Moulds for Casting Metals.
1. ARTHUR GEORGE BROWN, of 38 Victoria Buildings, Manchester, in the
County of Lancaster, Engineer, do hereby declare the nature of this invention to
be as follows:-
My improvements are applicable to the employment of metal moulds for
casting various articles, and particularly to the casting of light skeleton aluminium
or aluminium alloy frames.
These moulds are preferably made to conform outside to the shape of the casting
to be made, and they may, in certain cases, consist of a parallel part with bifurcated
ends. I prefer to construct the gate or runner through which the metal is to be
poured of the following form:-
One part is of comparatively large capacity, and forms a deep trough or pocket;
another portion is much smaller, and forms a pipe leading out of the former part
at a point above the bottom of the pocket, aud communicating with the rest of the
mould. There is also a riser situated at the highest part of the mould, and
communicating freely with it. This construction allows a free escape of air and
gases, thus reducing the risk of blow holes. I also prefer to provide one or more
small channels or grooves along one half of the inould, and partly or entirely
around the casting, and one or more corresponding grooves or ridges on the
opposite half of the mould; but where ridges are employed, I allow sufficient play
between these parts to receive a packing. This packing is to be sufficiently plastic
and elastic to form a complete filling of the grooves into which it is forced after
the sections of the mould are clamped together. The packing is preferably made
of asbestos and cotton, the latter of which will carbonize in solid form under the
influence of heat and retain the asbestos in place.
I prefer to construct the outer edges of the mould with bevelled or divergent
faces, to facilitate forcing in the packing, which packing should be retained in
place and covered by lute inserted between the divergent faces. This lute 19
preferably made of powdered asbestos and fireclay, preferably, rich in silicate of
soda, which will resist great heat without cracking or scaling, and has a tendency
to expand when heated.
When cores are employed to make parts of the casting hollow, I prefer to make
these cores of hollow metal, such as steel or iron pipes, and in certain cases,
I prefer to make these cores in parts, both to facilitate removal, and to permit of
different sizes of holes being made.
For making metal castings, I prefer to coat the interior of the mould and the
exterior of the cores with graphite, or similar material, to prevent sticking and to
facilitate removal.
Dated this 20th day of November 1895.
PHILLIPS & LEIGH,
Agents.

page_text: Improvements in and connected with Moulds for Casting Metals.
I, ARTHUR GEORGE BROWN of No. 38 Victoria Buildings, Manchester in the
County of Lancaster, Engineer, do hereby declare the nature of my invention and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :—
The present invention relates to improvements in and connected with moulds for
casting metals. These improvements are applicable to metal moulds and to the
casting of various articles therein, but particularly to the moulds for light skeleton
frames of aluminium or an aluminium alloy.
I have selected a mould for a cycle frame to be cast in aluminium or in
aluminium alloy, for illustration, because the peculiar requirements of such a
mould and such a casting are all met by my improvements. At the same time, it
must be distinctly understood that the application of the invention is not limited to
either cycle frames as castings nor to the metals above mentioned as material for
the castings.
Figure 1 is an elevation of the inner face of one of the mould boxes the parting
being along the line 1-1 of Figure 2.
Figure 2 is a plan of the complete mould.
Figure 3 is an end elevation looking at Figure 2 from the left hand.
Figures 4, 5 and 6 are detail sectional plans taken on the line 4-6 of
Figure 1.
Figure 7 is an elevation, partly in section, of one box, the cores and the
casting.
Figure 8 is a perspective view of the casting, cores and sprues, as they come
from the mould.
Figure 9 is a detail side clevation, of a portion of Figure 8, and on a larger
scale.
Figure 10 is a plan, partly in section, taken on the line 18-18 of Figure 9,
looking in the direction of the arrow.
Figure 11 is
Figure 10.
a detail sectional elevation, taken on the line 19-19 of
Figure 12 is a detail elevation illustrating the removal of the keys.
For the purpose of the present specification, the cycle frame in question, may be
regarded as a skeleton. The skeleton illustrated consists of a trapezoid and two
triangles. A, B, C, D, are the members of the trapezoid. E, H, B, and F, 1, B,
are those of the triangles, respectively. The member B is common to the trapezoid
and both triangles.
The members of the trapezoid are in one and the same plane while those of each
triangle are in one divergent therefrom. Each triangle is hereinafter referred to
as a bifurcation. These three planes, that of the trapezoid and those of the two
bifurcations are here regarded as vertical.
In addition to the eight members enumerated above, there are two more included
in the skeleton, viz., J and K, the former being a tie between E and F, and the
latter, one between H and 1.
Both mould boxes and cores are of a material which has a fusing point higher
than that of the metal to be cast. It may be regarded in the present case, as
either cast iron or cast steel. 30, 31, 32 and 33 are the four boxes which would
be required in the case of the cycle frame shown. 30 and 31 are parallel with each
other in respect of the trapezoid, that being as much of the skeleton as is in one
and the same plane. Such portion of each box 30 and 31, is hereafter referred to
as the body part. The said two boxes diverge from the meeting plane of their
body parts, in respect of the two bifurcations, such a diverging portion being

page_text: hereafter referred to as a divergent part. For the reason that between them, the
said two boxes provide the body portion of the mould cavity, (the latter being
that for the trapezoidal portion, A B C D, of the cycle frame) as well as that for
the outside half of each bifurcation, E H B, FI B; they are hereafter referred to
as the principal boxes. 32 and 33 are hereinafter referred to as the supplementary
boxes because they supplement the divergent parts of the principal boxes 30 and 31
by providing the body portions of the mould cavities for the inside halves of the
bifurcations E HB and FI B. Each supplementary box is shaped according to
the contour of the two sides of the respective bifurcation, whatever that contour
may be. Steady pins 34 project from the face of box 30 to enter dowel holes in
boxes 31 and 32 for the purpose of preventing lateral movement. A comparison
of Figures 1, 2, 7 and 8 clearly show the relationship between each part of each
mould box and the respective member of the skeleton.
The supplementary boxes are held to the principal box by the following method.
Shoulders 35 and 36 are formed on the divergent parts of box 30 (see Figures 1, 2
and 3) against which shoulders, the ends of box 32 abut. Shoulders 37 and 38
are likewise formed on the divergent part of box 31 for the ends of box 33 to abut
against. Shoulders 39 and 40 are formed on the ends of box 32 at a slight distance
from the shoulders 35, 36; and shoulders 41 and 42 are formed on the ends of
box 33 at a slight distance from shoulders 37 and 38. Keys 43 and 44 are seated
in the spaces between the said shoulders, and they rigidly bind the ends of the
boxes 32 and 33 to the divergent parts of the boxes 30 and 31.
The cores illustrated have, of course, special reference to the dimensions of the
members of the skeleton illustrated. They are preferably made of metal tubing
slightly tapered so as to facilitate withdrawal. 54 is a core in the centre of the
mould cavity for the member A. It rests in prints 55. 56 is a core in the centre
of the mould cavity for the member D. One end of it rests in a core print 57
while the other end of it terminates in a dowel pin 58 which enters a corresponding
socket in the core 54 59 is a core in the centre of the mould cavity for the
member B. The bottom end of it terminates in a dowel pin 60 which enters a
corresponding socket in the core 56, whilst the top end of it rests in a core
print 61.
The core for the convergent portions of the members E and F and J consists of
four keys 64, 65, 66 and 67 all of which abut against the key 43 at one end and
are there concaved to engage the convex end of the last mentioned key. The
upper ends of the said four keys are confined in a space 68 in the mould cavity
adjacent to the top end of the core 59. The top and bottom faces of the keys 64,
65, 66 and 67 engaged throughout part of their lengths with the adjacent interior
faces of the mould cavity. Recesses 69 are formed to allow of the flow of the
metal past the said keys upwards or downwards.
Lugs 70 are formed on the top faces of keys 64 and 65, and on the bottom faces
of keys 66 and 67, and engage corresponding recesses in the mould cavity, to
temporarily retain said keys against longitudinal movement until the metal is
poured. The contacting faces of the keys 64, 65, 66 and 67, are recessed at 71, 72,
to provide a cavity in which the member J is cast, and said keys are also concave
at their outer faces along the horizontal parting line to form the adjacent faces of
the members E F.
A core is provided for forming the space enclosed by the convergent end portions
of the members H, I, and K, which core comprises four keys, 75, 76, 77, 78,
constructed the same as the keys, 64, 65, 66 and 67 and placed in the lower portion
of the mould cavity in the same manner as the other said keys in the upper
portion.
48, 49 are two troughs or pockets. One half of them is incorporated with the
principal box 30 and the other on its fellow 31. They must be so positioned as to
communicate with the highest points of the mould cavity.
50, 51 are reduced channels from the troughs or pockets 48, 49, respectively, to
the mould cavity for the member B.

page_text: The two adjoining boxes of any portion of the mould are held together by means
of clamps 46. One jaw of a clamp enters a recess in the outside of one box, while
the other jaw is fitted with a set screw 47 working through it in the direction of
the opposite jaw, and engaging like the last mentioned jaw, in a recess in the
outside of the respective box.
The principal and supplementary mould boxes have, either or both, a groove z
extending around the mould cavity parallel with the outer edge with bevelled or
divergent faces y extending from the said groove to the outer edges of the boxes
as shown in Figure 4; and cords 62 are forced in between said divergent faces of
the boxes and into the said groove, which cords are retained in position by a lute 63
interposed between said divergent faces outside of and in engagement with the said
cords. The cords 62 are, preferably, made of asbestos and cotton because this
mixture will carbonise in solid form under the influence of great heat. The lute
is, preferably, made of asbestos and fire-clay, because this mixture will resist great
heat and cooling without cracking or scaling. When it is stated that cotton and
asbestos will carbonize solid, it is meant that cotton is employed as a medium to
retain the asbestos, in powdered form, in place during the operation of packing,
and that when the mould boxes are heated, the cotton will carbonize and remain in
place with the asbestos, instead of pulverizing or forming a fine ash and falling out
of place.
In practical use, the interior of the mould cavities is thoroughly cleaned and
then coated with a thin solution of graphite or similar material, which is then
allowed to dry. The cores 54, 56 and 59 are then placed in position, being first
coated with the solution above mentioned. Supplementary box 32 is then placed
on principal box 30 and clamped thereto, and the core keys 64, 65, 66 and 67 are
placed in position. The supplementary box 33 is then placed on the principal
box 31 and clamped thereto and the core keys 64, 67 and 75, 78 are placed in
position. The box 31 is then placed in proper contact with its fellow box 30 and
clamped thereto and the keys 43 and 44 are driven in. The cords 62 and lute 63
are inserted between the divergent or bevelled faces of the boxes, and are closely
packed therein.
There are formed on or fixed to the troughs 48, 49, eye plates 52, 53, extending
upwards. These plates are adapted to receive tackle by which the mould can be
moved from place to place.
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 peculiar system of a pouring gate, consisting of a trough or pocket
communicating with the mould by means of a reduced channel situated higher
than the bottom of the trough.
2. The system of grooves or channels surrounding the casting for the purpose of
receiving a packing.
3. The method of packing by means of cotton and asbestos, or other equivalents,
assisting the joints in a mould in such a way that no molten metal can ooze
through.
4. The method of luting the joints of the mould with a substance which will
expand on the application of heat and so assist the packing to retain the metal
within the mould.
PHILLIPS & LEIGH,
No. 22 Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.