IMPROVEMENTS IN MOULDING MACHINES
Year: 1879

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth and Company,
Patent Solicitors, at Frankfort on the Main, in the Empire of Germany, for
the Invention of "IMPROVEMENTS IN MOULDING MACHINES." A communica-
tion from Georg Sebold and Friedrich Neff, trading under the Firm of Sebold
and Neff, of Durlach, in the Empire of Germany.
Sealed the 20th January 1880, and dated the 11th August 1879.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office
of the Commissioners of Patents on the 11th August 1879.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort on the Main, in the Empire of Germany. "IMPROVEMENTS IN MOULDING
MACHINES." [A communication from Georg Sebold and Friedrich Neff, trading
under the Firm of Sebold and Neff, of Durlach, in the Empire of Germany.]
The present Invention has for its object, first, to effect the uniform ramming of
the sand in mould boxes, with patterns of irregular configuration; and, second, to
insure that the compression of the sand in the mould box shall always be effected
to the exact degree required, irrespective of variations in the nature and condition
of the sand. To effect the first named object, a mould is taken in gutta percha
when in a softened condition of the pattern to be moulded, and such mould is then
fixed on a shallow frame which is rammed with sand. The mould box having
also been filled with sand, the said frame with the gutta percha mould is inverted.
and placed on the upper open end of the mould box, so that the surface of the sand
filling of the former is in contact with the surface of the sand filling of the latter..
On now applying pressure to the top of the frame with the gutta percha mould it
will be evident that the sand will be compressed to the same degree round every part
of the pattern in the mould box, as at every such part there will be an equal depth of
sand by reason of the corresponding configuration of the gutta percha mould at top.
For accomplishing the second above named object the rammed mould box is placed
on a carriage mounted on a platform, that can be raised and lowered in a framing
by means of cranks on shafts connected thereto by links, the shafts being geared
together by toothed quadrants, and rotated by another toothed quadrant and

page_text: gearing worked by a crank handle. Above the mould box on the platform is a
strong platten hinged at one side to the framing so that it can be turned back to
admit the mould box and then closed down over it and secured by catches to the
other side of the framing. The platform being then raised the mould box is sub-
jected to the requisite pressure between it and the platten for compressing the sand.
The parts of the platform on which the carriage with the mould box rests are
separate from the other part, and rest upon the short arms of double ended levers,
having their fulcra on the platform and having their long arms loaded with
adjustable weights. Thus on forcing up the platform the compression of the sand
in the mould box will take place up to a degree corresponding to the load on the
levers, and if the forcing up of the platform be continued after such degree of com-
pression has been attained the only effect will be to raise the fulcra of the levers
without putting any additional pressure on the mould box. This is mounted loosely
on side pivots on the framing, so that after the compression has been effected and
the platform with the carriage is lowered again, and the platten raised, the mould
box resting on its pivots is swung round so as to have its bottom plate with the
pattern uppermost, and the pattern can thereupon be conveniently removed, after
which the mould box is removed from the machine. In order to prevent the sand
from getting on to the rails of the platform while the mould box is being inverted
and the pattern removed, a tray on wheels is provided hooked on to the carriage,
so that as this is run from und
hould box the tray is brought underneath it.
For conveniently filling the _box with sand while on the platform of the
machine, a hopper supported on wheels may be provided on a stand at the side of
the machine containing mould sand, and having a spout reaching over the mould
box so that the sand can be readily shovelled from such hopper into the mould
box. A shoot is also provided for conveying the surplus sand from the mould box
into a receptacle below.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frank Wirth in the Great Seal Patent Office on the 22nd January
1880.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort on the Main, in the Empire of Germany. "IMPROVEMENTS IN MOULDING
MACHINES." A communication from Georg Sebold and Friedrich Neff, trading
under the firm of Sebold and Neff, of Durlach, in the Empire of Germany.
Moulding machines that have heretofore been employed for the purpose of
dispensing more or less with skilled manual labour have only imperfectly fulfilled
their object, from two causes, namely: First, because the pressure exerted by the
machine on the sand in the mould boxes was effected by means of a flat plate, so
that with patterns of irregular configuration the sand was compressed more at the
higher parts of thepattern than at the lower parts, such unequal compression pro-
ducing injurious effects that are well known. To remedy this, wood pressing plates

page_text: have been used, on the surface of which the configuration of the pattern was repro-
duced by carving, and irrespective of the impossibility of producing an exact
counterpart of the pattern by this means, this arrangement has the further defect
that the sand is thereby compressed to a greater degree at the lower parts of the
pattern than at the higher parts. Fig. 1 of the accompanying Drawings shewing
the two above described modes of moulding, namely, on the left hand side by the
use of a flat plate, and on the right hand side by the use of a carved plate, will show
at a glance the truth of what has been stated above.
The second defect arises from the fact that the operator does not know when
the pressure upon the mould sand has been effected to the requisite degree. If the
sand were always equally moist and of the same degree of fineness this might be
remidied by making a mark on the filling frame on the top of the mould, to
which the pressing plate should descend in compressing the sand. But as the
moisture and fineness of the sand varies, this is not possible, because with one and
the same stroke the sand would be too tightly rammed if more moist than usual,
and too slightly rammed if dryer than usual.
The present Invention has for its object to obviate these defects, and consists in
employing for this purpose means which I will now describe.
Fig. 2 of the Drawings shews the arrangement employed for obviating the first
above described defect. On the base plate a, having the pattern 6 fixed thereon, is
placed the mould box c, and into this is run heated gutta percha, or other substance,
that on cooling becomes sufficiently rigid to exert the requisite pressure during the
subsequent ramming process. By this means a reversed counterpart of the pattern
is obtained, which can be removed on cooling, and which now forms the pressing
plate d. In moulding the mould box c is filled with sand as usual and levelled.
The plate d is then inverted so that its figured surface is uppermost, and the filling
frame e having been placed upon it, it is also filled with sand and levelled. The
top of the filling frame having been closed by a piece of sheet metal, the frame and
pressing plate are inverted and placed on the mould box, as shewn at Fig. 2, the
sheet metal being then withdrawn. It will now be seen that as the sand in the
uncompressed state is everywhere of uniform thickness over the pattern, its com-
pression will also take place uniformly in all parts, resulting in the production of
a perfectly homogenous sand mould, such as could not even be produced by the
most skilled operator in hand ramming. Fig. 3 shews a plan of the mould box and
3 pattern.
For obviating the second above mentioned defect arrangements are employed, as
shewn in Figs. 4 to 6 of the Drawings. The table A, which can work up and down
in suitable guides, supports the carriage B carrying the mould box C, the upward
motion of the table causing the top of the mould box to be pressed with sufficient
force against the platten K to effect the ramming of the sand mould. The action
might, however, be reversed, that is, the table be made stationary and the platten
be pressed down on the mould box. The upward motion of the table is effected by
four segmental racks D connected to the table by links E, and receiving motion
from the toothed segment F, gearing G and crank handle H. The weight of the
table and its load is balanced by the balance-weight D' on the axis of one of the
segments. The platten K is hinged to the framing on one side, so that it can be
turned back. When it is required to exert pressure it is held by clamping pieces L,
which are pivotted to the framing at M, and are connected together by a link N,
so that a push, is sufficient for throwing them out of gear for freeing the platten.
The weight O connected to the front end of the platten holds this in balance. The
platten is adjustable in height, so that higher mould boxes can be used.
framing is for this purpose extended upwards and provided with pin holes, in which
the pivots of the platten can be introduced. The clamps L can also be changed for
this purpose. The truck B does not rest directly upon the surface of the table, but
on the ends of the pius p, that can slide in holes in the table, and whose lower
ends are supported by the short arms of levers R, the long arms of which are loaded
by adjustable weights Q, to exert with their short ends an upward pressure against
The

page_text: the pins p, corresponding to the maximum pressure to which the sand mould is to
be subjected. Thus on the raising of the table A the levers R (the pivots of
which are carried thereby) keep the truck and mould box pressed up against the
platten until the maximum desired compression of the sand mould has been attained,
whereupon if the upward motion of the table be continued the mould box and
truck in being pressed downwards by the platten will simply depress the pins
against the action of the weighted levers, which will accordingly have their
weighted ends raised so that no additional pressure will be exerted on the sand
mould. The degree of compression of the sand mould may be regulated by
changing the position of the weights on the levers R. After completing the
compression the table A is lowered, the platten K is raised, and the truck is
removed from under the mould, which rests with trunnions in the framing. This
mould is then swung round so that the pattern plate is uppermost, and this is
removed after loosening it with a few taps with a hammer. In order that no sand
may fall on the table and guide rails a tray S is attached to the truck in such
manner that in rising with the table the coupling hook T thereof disengages itself
from the tray, and engages therewith again on the descent of the table. In order
that the mould box may be conveniently filled with sand a hopper U, Fig. 7,
running on wheels on the framing is provided, containing sufficient sand for several
filling operations, which hopper is pushed back when a mould box is under the press.
Every time a fresh mould box has to be filled the hopper is pushed forward, the
platten being turned up, so that the hopper abuts close against the mould box. The
sand is then pushed into the latter by a rake, and on levelling, the surplus sand falls
through the shoot V, Fig. 6, into the box W below. Fig. 8 shews the platten in its
various positions.
Having thus described the nature of the said Invention, and in what manner
the same is to be performed, as communicated to me by my correspondents, I
claim,
.
First. The method herein described with reference to Fig. 2 of the Drawings,
whereby a uniform depth of sand is provided at all points between the pattern and
the pressing plate of a mould box.
Second. The combination in a moulding machine of a table A with toothed seg-
ments D, links E, segments F, gearing G, and crank handle H, substantially as
herein described.
Third. The combination of the table A, arranged to work up and down with the
pins P and weighted levers R, arranged and operating substantially as and for the
purposes herein set forth.
Fourth. The use in moulding machines of a platten K adjustable in height and
arranged to be raised and lowered, substantially as herein described.
Fifth. The use in moulding machines of a mould box capable of turning on trun-
nions, in combination with the truck B and tray S, substantially as herein
described.
Sixth. In a moulding machine the combination of the sand hopper U, shoot V,
and receptacle W, substantially as and for the purposes herein described.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand and
seal, this Sixteenth day of January, in the year of our Lord One thousand
eight hundred and eighty.
FRANK WIRTH. (L.S.)