Note: Descriptions are shown in the official language in which they were submitted.
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PATENT APPLICATION
~f ..
KURT FISCHER
and
GEORGES LOUYS
for
APPARATUS FOR COMPACTING GRANVLAR MOL~ING ~TERIAL
Field Of The Invention
The present invention relates to an apparatus for
compacting granular molding materials which can be
readily adapted to different molds.
Back~round Of The Invention
There are numerous conventional methods and appara-
tus for compactin~ molding matPrials wherein the molding
materials a~e compacted by a surge o~ pressure resulting
from an exothermic reaction of a ~uel mixture or from a
highly pressurized gas~ For example r in U.S. Patent No.
3,170,202 to Huston et al, a combustion chamber receives
a fuel mixture and is placed over a mold unit. Follow-
ing formation of a closed system by the combustion
chamber and mold unit, the exothermic reaction is
triggered creating a surge of pressure on the molding
material.
In another system disclosed in DT-PS l9 61 234, a
pressure chamber stores a highly pressurized gas, and is
detachably connected with a mold unit to form a closed
system~ The compressed air~is highly pressurized in the
pressure chamber and expands suddenly over the molding
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material upon opening of a valve to compact the mass of
molding material.
~ oth of these systems experience the same problem
in that each system can only be used for one size o~ mold
unit. T~us, a foundry requires a plurality o~ these
conventional compacting mechanisms for the different mold
unit si~es.
Summary Of ~he Invention
An object of the present invention is to provide
an apparatus for compacting granular molding materials
which can form a closed system with and treat molding
materials in different mold unit configurations and
sizes, while employing the same compacting apparatus.
According to the present invention there is
pxovided an apparatus for compacting granular molding
material, particularly foundry molding sand, comprising:
a mold unit including a pattern plate supporting
apattern thereon, and a molding frame coupled to and
surrounding said pattern plate and said pattern;
a pressure chamber forming a closed system with
said mold unit;
pressure means, ~oupled to said pressure chamber,
for generating a shock pressure in a gaseous medium to be
applied on a surface of loose molding material in said
mold unit;
an adapter, mounted between said pressure chamber
and said mold unit, for defining a passageway between said
pressure chamber and said mold unit; and
means, mounted on said adapter, for adapting the
transverse cross-sectional area of said passageway to said
mold unit.
Other objects, advantages and salient features of
the present invention will become appar~nt from the
following detailed description, whieh, taken in conjunction
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with the annexed drawings, discloses preferred embodiments
of the present invention.
Brief Description Of The Drawin~s
Referring to the drawings which form a part of this
5 disclosure:
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s~
Figure 1 is a side elevational view in section of
an apparatus for compacting molding material by an
exothermic reaction according ~o the present invention;
Figure 2 is a side ~levational view in section of
an apparatus for compacting molding materials by highly
pressurized, compressed air according to the present
lnventlon .
Detailed Description
OE Preferred Embodiments Of The Invention
Fig. 1 illustrates an apparatus according to the
present invention with a pressure chamber 1 for an
exotherrnic reaction. The bottom joint of pressure
chamber 1 is formed by an insert 2 with a passage
opening 3, which insert is mounted in an adapter 4.
Adapter 4 is carried by supports 5~ Opening 3 can be
rvund, polygonal, conical or cylindrical. Advan-
tageously, insert 2 is replaceable. The dimensions of
the opening 3 can he varied as necessary~ so that a
number of mold unit configurations and sizes can be
used.
A cover 6 forms the top of pressure chamber 1. A
motor 7 for a fan 8 is mounted on cover 6 with the fan
projecting into chamber 1~ A conduit 9 is mounted
within ~he pressure chamber to increase the efec-
tiveness of fan 8. A fuel `feed line 1~, e.g., for
natural gas, is attached to the interior of the pressure
chamber. The fuel is fed from a ~uel source through a
dosing device 11. An ignition plug 12, controlled ~y an
ignition control 13, is mounted in cover 6 of chamber 1
to trigger the exothermic reaction required for creating
a pressure surge. Alternatively, plug 12 could be
mounted in the area o~ conduit 9.
~ he space defined between supports 5 and adapter 4
encloses a mold unit. The mold unit comprises a molding
frame including a frame 16 and a molding box 17. A
pattern plate 18 with a p~ttern are surrounded by the
molding frame such that the molding unit can be loosely
filled with granular molding matexial. The filled mold
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unit is mounted on a li~ting table 20. A r~ller train
21 can be used or conveying unit to and from the
pxessure chamber.
Figure 2 illustrates an apparatus for compacting
granular molding materials with a pressure chamber 25
employing a highly pressuri~ed gas, e.g. compressed air,
to produ-e a surge of yas pressure. The pressure
chamber 25 is superimposed on an insert 26 with a
passage opening 27. Insert 26 mounted in an adapter 28.
The adapter 28 is configured as a plate and is supported
by supports 29. A compacting unit comprising pressure
chamber 25 and adapter 28 is connected with the mold
unit to form a closed system.
The top of pressure chamber 25 is formed by a cover
30 which supports thrust piston drive 31. Thrust piston
drive 31 operates a valve 32 covering passage opening
27. A gaseous or a liquid medium can be used for
operating thrust piston drive 31. Additionally, elec-
trically operated devices could also be used for thrust
piston drive 31.
An aeration conduit 33 extends from passage opening
27 to a valve 34 for relieving pressure in chamber 25.
~n optional sound damper 35 can connect valve 34 to the
surrounding atmosphere.
An air feed line 37 passes through cover 30. Line
37 includes a manometer 36 controll~d ~y a valve 38 to
build-up pressure in pressure chamber 25.
Similar to the apparatus of Figure 1~ a mold unit
is arranged under passage opening 27, i.e. under valve
32. The apparatus is illustrated in the position just
after the molding material 22 has been compacted. In
Figure 1, the apparatus is illustrated at the point when
th~ molding material 22 is still uncompacted.
The mold unit used corresponds to that described in
connection with Figure 1.
The operation of the device at Figure 1 involves
filling the mold unit with a dosed quantity of molding
material. The filled mold unit is conv~yed by the
s~
roller train 21 to the li~ting table 21, and is then
raised under the passage opening 3 of the insert.
A~ter the mold unit is connected tightly to the
adapter 4, a dosed quantity of a fuel flows from the
dosing devi~e 11 into the pressure chamber~ where the
fuel is combined with the air present in the pressure
chamber to form a fuel-air mixture. The fuel-air
mixture is forced to move rapidly by movement of the fan
8. During the rapid movement of the fuel-air mixture,
the ignition control 13 causes the ignition plug to
trigger an exothermic reaction in the fuel-air mixture
creating a surge of pressure. After the reaction, the
mold unit can be lowered from the adapter 4 and the
buxned gases can be exhausted through the opening
between the adapter and the mold unit.
The operation of the apparatus of Figure 2 differs
only in the manner the surge o pressure is produced.
After the assembly of the mold unit and pressure
chamber 25 to form a closed system, a gaseous medium,
for example, compressed air, is conveyed through feed
line 31 via the pressure control valve 38 to develop a
compression pressure. Alternatively, the compression
pressure can be developed before connection with the
mold unit.
After the mold unit is connected and the pressure
is built up in the pressure chamber, val~ 32 is opened
suddenly and the pressurized air is expanded and forms a
pressure surge through tha opening 27 and over the
molding material surface.
Following compacting of the molding material, the
valve 32 is closed and the pressure medium remaining
over the molding material surface is exhausted. A
damper 35 can show the outflow of compressed air. After
relieving the pressure over the molding material, valve
34 is closed and the mold unit is lowered.
The system of the present invention is advantageous
since mold units of different si~es and geometric shapes
can be compacted without difficulty and with relatively
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low capital outlay. The same compacting mechanism can
be used with differently sixed and shaped mold units
merely by changing the xeplaceable insert 2 or 26. The
present invention can also be used for molding opera~
tions wherein compactirlg is performed by press tools.
While various embodiments have been chosen -to
illustrate the invention, it will be understood by those
skilled int he art that various changes and modifica-
tions can be made therein withou~ departing from the
scope of the invention as defined in the appended
claims.
