US2793409A - Machine for the production of foundry cores and foundry moulds using compressed air - Google Patents

Machine for the production of foundry cores and foundry moulds using compressed air Download PDF

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Publication number
US2793409A
US2793409A US456205A US45620554A US2793409A US 2793409 A US2793409 A US 2793409A US 456205 A US456205 A US 456205A US 45620554 A US45620554 A US 45620554A US 2793409 A US2793409 A US 2793409A
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sand
air
compressed air
chamber
valve
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US456205A
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English (en)
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Hansberg Fritz
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C15/00—Moulding machines characterised by the compacting mechanism; Accessories therefor
    • B22C15/23—Compacting by gas pressure or vacuum
    • B22C15/24—Compacting by gas pressure or vacuum involving blowing devices in which the mould material is supplied in the form of loose particles

Definitions

  • the invention relates to a foundry machine, in which the core-sand or moulding sand is introduced into the core-box or moulding box by means of compressed air or other pressure medium.
  • the moulding sand with which a sand container is filled should be mixed as thoroughly as possible with air so as to achieve a completely pneu-' matic loosening up of the sand before blowing, and to ensure that during the blowing operation each grain of sand is first surrounded with and enveloped by the compressed air and only then blown into the core-box or moulding box.
  • moulding sand is simply injected abruptly into the core-box or moulding box as a compact mass Without any admixture of air.
  • the necessary acceleration is imparted to the moulding sand by resilient pressure, for example by compressed air acting as a resilient piston on an end-face of a column of sand, and forcing it. abruptly through a nozzle into the core box or moulding box.
  • the sand While the compressed air enters from one side and presses on the end-face of the column of sand, the sand passes in the form of a compact jet, through the nozzle on r the other side into the box, which it fills partially or wholly according to the amount of sand subjected to pressure.
  • the sand in the form of a compact, coherent body, is enabled to fill absolutely all the hollow spaces in the moulding or core box.
  • a fundamental difliculty withthis method of operation lies in the fact that the compact mass of moulding sand, which also remains compact when injected into the mould-- ing or core box, experiences a high surface friction, for which reason formerly only small amounts of sand could be shot.
  • the inventor has therefore already suggested a machine working with a pressure chamber, by means of which,
  • the perforations in the insert as required by the shooting principle with its ramlike method of operation which takes place without any admixture of air, are made so small and are so spaced that the compact column of sand is merely loosened from the side of the insert and no particular turbulence occurs between the supply of sand and the air, when the surrounding annular air-chamber is likewise suddenly placed under pressureduring the abrupt acceleration procedure.
  • the invention relates primarily to such a shooting machine, but it can also be applied in suitable cases to blowing machines working on the sand-air mixture system, for example with those havingan annular head for admitting the blowing air.
  • the compressed air should enter the sand storage container not slowly but suddenly, and in a shooting machine having a pressure chamber particular efforts are made to ensure that the amount of compressed air stored in the pressure chamber enters the sand 'storage container as quickly 'as possible and as .a Whole,-and hence exerts as strong an impact as possible on the head of the column of sand.
  • the pressure chamber is arranged-immediately before the inlet of the.
  • a valve is interposed which uncovers as large a ,passage aspo'ssible and can be controlled as quickly as possible, for which reason the inventor has already suggested that for ab'rup't control such a high speed valve should be fitted with a pneumatic piston.
  • the horizontal mounting of the high-speed valve has the disadvantage that the compressed air, which only enters the annular chamber at one point, is not evenly distributed therein simultaneously, which is important in such a sandshooting machine which operates in a matter of seconds, because, as a result, ramming air no longer enters the insert simultaneously from all sides as intended, and its ramming eliect is not such as could be achieved with an even small amount of compressed air, given simultaneous equal entry from all sides.
  • the air inlet valve in the form of an annular slide valve which surrounds the sand storage container and is arranged parallel to its axis and preferably concentric therewith, the annular slide valve working either in the manner of a rotary slide valve with rotary displacement, or in the manner of a sleeve valve with axial displacement.
  • annular slide valve is not, however, restricted to sand shooting machines working on the shooting principle, and such an annular slide valve can also be used, in suitable cases, in blowing machines working on the sand-air mixture principle.
  • the compressed air simultaneously compresses said column of sand by means of its lateral pressure in such a manner that no particular turbulence or mixing of the moulding sand with air takes place and, solely by abrupt acceleration of the whole column of sand, a smaller amount of sand necessary for filling the core or moulding box, is shot into the core box without any particular air-sand blowing action.
  • annular slide valve acting as a wide-aperture high-speed valve, at the upper end of the sand storage container, inside the annular chamber or immediately adjacent thereto, in such a manner that the compressed air stored in the annular chamber end of a compressed air chamber which may be connected thereto, can suddenly emerge from the annular chamber and enter the upper portion of the sand storage container radially from all sides when the annular slide valve is actuated.
  • the annular slide valve may conveniently be constructed from a hollow cylinder in such a manner that it can slide axially on the outer surface of the sand storage container.
  • the annular slide valve in the shape of a hollow cylinder may be fitted with an annular control
  • the insert can preferably be closed by means piston, which is preferably mounted at the lower end of the hollow cylinder.
  • the annular control piston may be spring-loaded on one side, but it is advantageously constructed as a double-acting piston, whereby the one annular side of the piston may be in direct communication with the annular chamber in such a manner that the pressure from the ramming air stored in the annular chamber permanently loads it.
  • This has the advantage that, when the other annular side of the piston is relieved of pressure by means of a control valve, the opening of the annular slide valve takes place abruptly and automatically as a result of the ramming air stored in the annular chamber.
  • the compressed air for control simply being taken from the annular chamber, that face of the double-piston which is permanently loaded by the pressure of the compressed air stored in the annular chamber, is provided with a smaller area on which the pressure acts than the other face of the piston.
  • springs may be provided which tend to restore the annular slide valve to its closed position.
  • the sealing in the closed position may take place in such a manner that the upper edge of the annular slide valve in the shape of a hollow cylinder is pressed against a seal.
  • the sand storage container with upper perforations, simply to leave its upper end open in the form of a ring.
  • the slide valve may conveniently be provided at its upper end with a seal which engages round the upper end of the sand storage container and passes into the inner chamber.
  • the sand storage container may conveniently have a flange with which it can be withdrawn from the machine frame, and the sand storage container and the annular slide valve construction surrounding it may be constructed as a complete unit which can be removed as a whole from the head of the machine frame when the flange bolts have been undone.
  • the annular chamber In order to use the annular chamber not only for distributing the compressed air flowing out of the compressed-air chamber attached directly thereto, but also at the same time directly as a compressed air chamber, it is a particular advantage to surround substantially the whole of the sand storage container and the annular slide construction surrounding it, with a hollow chamber which serves to store the ramming air which causes the ramming effect, which air can then enter the sand storage container directly through the annular slide valve.
  • This hollow chamber may then simultaneously act as a holder in that it may be constructed as the headpiece of the machine frame carrying the sand storage container.
  • a second compressed air chamber maybe provided upstream of said hollow chamber serving to store the ramming air causing the actual ramming effect, from which second chamber the compressed air can flow through a small regulating valve, the setting of which prolongs or shortens the shot, thus adapting it to the size of grain or other factors making desirable such variation.
  • This second compressed air chamber may, for example, be housed in the machine upright, or said upright itself may be constructed to form the compressed air chamber.
  • the insert for the sand container which is provided With narrow slots or the like, may, like the sand storage greases;
  • the accompanying drawing shows diagrammatically, in vertical section, a preferred embodiment of the machine according to the invention, using the annular slide valve construction, in a sand-shooting machine fitted with a slotted insert, the parts which are not absolutely necessary for an understanding of the invention being merely indicated or omitted altogether, while the drawing shows only the upper part of the machine without the working table and the core box or moulding box.
  • upright 1 carries atits upper endra headpiece 2, which, at the same time, is constructed as a hollow chamber 3, in which sand storage container 4, with the annular slide valve construction surrounding it, is inserted like a stopper from below, the inserted unit being held by a flange 5 provided on the sand storage container 4 near its lower end, by means of flange bolts 6.
  • the sand storage container 4 carries at its lower end a detachable shooting head 9 constructed in the form of a hollow chamber and equipped with a nozzle 7 and a perforated plate 8. Inside the sand storage container 4 there is mounted, with a slight clearance gap 12, an insert or inner container 19, which has small perforations in the form of slots 11 at suitable points, through which the air present in the gap 12 acts on the column of sand with which the insert is filled, and during the acceleration procedure said air compresses said column of sand laterally to some extent, when the annular gap 12 is likewise placed under pressure, during the ramming effect of the compressed air stored in the hollow chamber 3.
  • the slotted inner container 10 In order that most of the compressed air stored up in the hollow chamber 3 may conveniently enter the space inside the top of the slotted inner container 10, the latter is provided all round the upper end with a large number of horizontal slots 13.
  • the upper end of the slotted inner container 16 is centred in two cover plates 14 and 15, between which a sand-charging shutter 16, which may conveniently be pneumatically controlled, slides on seals, said shutter being shown in the drawing in its open position, and permitting convenient refilling with moulding or core sand from a sand-charging tray 17.
  • the air inlet valve in the form of an annular slide valve 18, which is constructed as an elongated hollow cylinder 19, which embraces the part of the sand-storage container 4 which projects into the hollow chamber 3, and is slidable axially on the outside surface of the sand storage container 4 or on projecting slideways provided on said outer surface.
  • the sand storage container projecting into the hollow chamber 3 isopen in the form of a ring at its upper end 20 and in order to protect the sliding parts of the slide valve from sand, the hollow cylinder 19 of the slide valve 18 is provided at its upper end 21 with a seal 22 which engages round the upper end 24 of the sand storage container 4 and passes inside the sand storage container 4.
  • the inner surface of the sand-storage container 4 is somewhat set back at the upper end 20 where the embracing seal 22 slides on it, so that an adequate clearance remains out ward of'the insert 10 in the region of the seal 22.
  • the hollow cylinder 19 of the slide valve 18 is fitted at its lower end with an annular control valve 23 which is constructed as a double-acting piston having two annular faces 25, 26 and slidable in a cylinder 24 formed by the hollow chamber 3.
  • the face 25 of the piston is in direct communication with the annular chamber 3 so that the pressureof the compressed air stored in the annular chamber 3 constantly loads it and tends to urge the piston23 and with it the annular slide valve 18 into its lower dead position.
  • the other face 26 of the piston is in communication by a duct 31 with a control valve 27, and the pressure acting on the face 26 of the piston tends to urge the piston 23 into the upper dead position, as a result of which the annular slide valve 18 is pressed'with its upper edge 28 against a seal 29 and thus the annular hollow chamber 3 is sealed off from the sand storage container 4.
  • the control valve 27 is mounted for easy access on the front of the machine and is covered by a housing 30.
  • the control valve 27 may be supplied with the same compressed air, e. g. simply from the hollow chamber 3, the area of the face 26 of the piston, on which acts the air pressure regulated by control valve 27 to close the slide valve 18, has an area greater than the area of the other face 25 of the piston on which the pressure in chamber 3 acts, so that in spite of the pressure of the ramming air stored in the annular chamber 3 loadingthe face 25 of the piston, the slide valve 18 is reliably pressed in an airtight manner against the seal 29 when .in the positionof rest.
  • the slotted insert 10 is filled from the top with moulding sand from the sand-charging tray 17, and then the sand-charging shutter 16 is pushed into its closed position, for example by pneumatic operation by the control valve 27 arrangedto perform this function also.
  • the inner chamber of the sand storage container 4 or of the insert 10 is thereby closed at the top in an airtight manner.
  • the machine table (not shown) is raised and the core-box (not shown) which is placed thereon, is pressed against the perforated plate 8 and the nozzle '7.
  • the chamber 3 has been filled with compressed air from an ordinary compressed air line for example via an intermediate chamber and a regulating valve, while the compressed air acting on the face 26 of the piston holds the annular slide valve 18 with its upper edge 23 against the upper seal 29, against the action of the compressed air acting on the face 25 of the piston.
  • the machine is then again ready for another shot.
  • control valve 27 In practice, the individual manipulations of the control valve 27 supplement and overlap each other so that the operator controls the machine with only a few manipulations and the machine is again ready for a new shot after a few seconds.
  • a foundry machine employing compressed air for ramming cores and filling molding boxes with molding sand, said machine comprising a container for the sand to be rammed, said container having in its bottom a sand outlet and at its top an air inlet, a structure forming a storage chamber for pressure air surrounding said container for supplying pressure air thereto, an air control valve means for controlling the admission of pressure air through said air inlet, said valve means including a tubular valve member surrounding the top portion of the container having said air inlet and being movable between a closing position covering said air inlet and an open position uncovering said inlet, and actuating means for moving the valve member from one position into the other.
  • a foundry machine employing compressed air for ramming cores and filling molding boxes with molding sand, said machine comprising a container for the sand to be rammed, said container having in its bottom a sand outlet and at its top an air inlet, a perforated lining member disposed within said container spaced apart from the wall thereof and open ended at its edge adjacent to said air inlet, said air inlet communicating with the inner space in the container as defined by said lining member and also with the space between the container wall and the lining member for directing air into said inner space of the container from the top thereof and also laterally into the inner space through the perforations in said lining member, a structure forming a storage chamber for pressure air surrounding said container for supplying pressure air thereto, an air control valve means for controlling the i admission of pressure air through said air inlet, said valve means including a tubular valve member surrounding the top portion of the container having said air inlet and being movable between a closing position covering said air inlet and an open position uncovering said inlet
  • a foundry machine employing compressed air for ramming core and filling molding boxes with molding sand, said machine comprising a generally cylindrical container for the sand to be rammed, said container having on one end a sand outlet and at the other end an air inlet, a structure forming a storage chamber for pressure air surrounding said container for supplying pressure air thereto, an air control valve means for controlling the admission of pressure air through said air inlet, said valve means including a generally cylindrical valve member surrounding at least the part of the container having said air inlet and disposed coaxially with the container, said valve cylinder being mounted axially 8 movable between an open position uncovering said air inlet and a closed position covering said inlet, and actuating means for moving the Valve cylinder from one position into the other.
  • said actuating means comprise a control cylinder, a piston slidable in said cylinder and connected to the valve cylinder for movement in unison therewith, said piston having faces of different area, said air pressure chamber being in communication with cylinder spaces on both sides of the piston, and control means for rendering selectively effective the pressure air on one side of the piston to move the valve cylinder from one position into the other.
  • a machine wherein the space of the control cylinder on the side of the small piston face is in direct communication with said pressure air chamber and a conduit connects the space of the cylinder on the side of the large piston face with said chamber for normally urging the valve cylinder into its closing position, and wherein check valve means are included in said conduit for controlling the flow of pressure air through the same, opening of the conduit effecting movement of the valve cylinder into its open position.
  • control cylinder encompasses said container coaxially therewith and said piston is an annular piston.
  • a foundry machine employing compressed air for ramming cores and filling molding boxes with molding sand, said machine comprising a frame structure including a generally cylindrical open ended space, a perforated cylindrical insert for receiving a charge of ramming sand fitted in said space coaxially therewith and having a diameter smaller than said cylindrical space to form an annular chamber defined by said insert and the respective wall portion of said frame structure, a sand outlet nozzle mounted adjacent to one end of said insert in alignment therewith, the opposite end of the insert having an air inlet, said air inlet communicating with said annular chamber and the interior of said insert, said frame structure further including a chamber for pressure air surrounding the part of the insert having said air inlet to supply pressure air to the interior of said insert and said annular chamber, an air control valve means for controlling the admission of pressure air through said air inlet, said valve means including a generally cylindrical valve member surrounding at least the part of the insert having said inlet and disposed coaxially therewith, said valve cylinder being mounted axially movable between an open
  • a machine wherein the part of the insert having said inlet protrudes from the wall portion of the frame structure defining said cylindrical .space, and wherein a further wall portion of the frame structure in conjunction with the wall portion forming the cylindrical space defines a ring space juxtaposed to said air inlet and communicating with said air pressure chamber, said valve cylinder respectively opening and closing the communication between said ring space and said air pressure chamber in response to an axial displacement of said valve cylinder.
  • sealing means are provided on said further Wall portion, said valve cylinder engaging said sealing means in its closed position to seal the interior of said insert from said pressure chamber.
  • a machine according to claim 10 wherein the end of the valve cylinder coacting with said sealing means is bent back into slidable engagement with the inside of the wall portion defining said cylindrical space to prevent the ingress of sand into the air pressure chamber.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Casting Devices For Molds (AREA)
US456205A 1954-02-16 1954-09-15 Machine for the production of foundry cores and foundry moulds using compressed air Expired - Lifetime US2793409A (en)

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DE346657X 1954-02-16

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US (1) US2793409A (en))
BE (1) BE535648A (en))
CH (1) CH346657A (en))
FR (1) FR1124466A (en))
GB (1) GB763036A (en))
NL (1) NL104033C (en))

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3089207A (en) * 1959-04-09 1963-05-14 Osborn Mfg Co Blow-squeeze molding machine
US4140171A (en) * 1977-08-08 1979-02-20 Ashland Oil, Inc. No bake blower apparatus for making sand cores
DK153634B (da) * 1975-12-05 1988-08-08 Fomes Sa Blaesehoved til indblaesning af sand i forme til fremstilling af stoebekerner.
US4794976A (en) * 1986-05-13 1989-01-03 Guido Peterle Molding sand loading and injecting head, in particular for molded core forming machines
US4815517A (en) * 1986-08-08 1989-03-28 Joachim Laempe Core making machine
US5052465A (en) * 1989-02-10 1991-10-01 Erana Agustin Arana Drive mechanism for core release machines

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3225396A (en) * 1962-03-23 1965-12-28 Hansberg Fritz Seal for control slide of core and mold making machine

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE557503C (de) * 1931-02-08 1932-08-24 Masch U Werkzeugfabrik Kabel Verfahren und Formmaschine zum Fuellen von Form- und Kernkaesten mit Formsand durch Druckluft
US2611938A (en) * 1949-06-15 1952-09-30 Hansberg Fritz Machine for ramming foundry cores by means of compressed air
US2654924A (en) * 1949-01-06 1953-10-13 Wood David Howard Closure device for feed chambers for finely divided materials

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE557503C (de) * 1931-02-08 1932-08-24 Masch U Werkzeugfabrik Kabel Verfahren und Formmaschine zum Fuellen von Form- und Kernkaesten mit Formsand durch Druckluft
US2654924A (en) * 1949-01-06 1953-10-13 Wood David Howard Closure device for feed chambers for finely divided materials
US2611938A (en) * 1949-06-15 1952-09-30 Hansberg Fritz Machine for ramming foundry cores by means of compressed air

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3089207A (en) * 1959-04-09 1963-05-14 Osborn Mfg Co Blow-squeeze molding machine
DK153634B (da) * 1975-12-05 1988-08-08 Fomes Sa Blaesehoved til indblaesning af sand i forme til fremstilling af stoebekerner.
US4140171A (en) * 1977-08-08 1979-02-20 Ashland Oil, Inc. No bake blower apparatus for making sand cores
US4794976A (en) * 1986-05-13 1989-01-03 Guido Peterle Molding sand loading and injecting head, in particular for molded core forming machines
US4815517A (en) * 1986-08-08 1989-03-28 Joachim Laempe Core making machine
US5052465A (en) * 1989-02-10 1991-10-01 Erana Agustin Arana Drive mechanism for core release machines

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GB763036A (en) 1956-12-05
NL104033C (en))
CH346657A (de) 1960-05-31
FR1124466A (fr) 1956-10-11
BE535648A (en))

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