Back to results
US 4,286,937 AGranted
Production of sand moulds
AssigneeAlfelder Maschinen- und Modell-Fabrik Kunkel, Wagner & Co. KG
InventorWalter Ahrens
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeAlfelder Maschinen- und Modell-Fabrik Kunkel, Wagner & Co. KG
InventorWalter Ahrens
Estimating the term…
This provides a way of producing a sand mould which does not require heavy echanical presses or violent vibration to ensure sand properly fills tight patterns in a mould. Sand is put into a buffer zone 40 via a feed device 2,3. Below the buffer zone 40 is a flask 10 and pattern plate 14, and the space between the buffer zone 40, the flask 10 and the plate 14 defines a charging chamber through which the sand must fall to produce the mould. This space, and preferably the buffer zone as well, is evacuated. This eliminates air resistance to the falling sand and, as a result, the sand fills the mould properly. The sand is allowed to fall after the vacuum has been established. The reason for evacuating the buffer zone is to bleed the sand of air. It is preferred that the pressure in the charging chamber is reduced further than that in the buffer zone, since a difference in pressure will further accelerate the sand towards the pattern plate.
An apparatus for producing a mould, comprising means for putting a moulding compound in a buffer zone, means for reducing the pressure in the buffer zone and in a charging chamber over a pattern below atmospheric pressure, and means for transferring the moulding compound from the buffer zone into the charging chamber under gravity while maintaining the vacuum or partial vacuum produced on reducing pressure in the buffer zone and charging chamber below atmospheric pressure.
An apparatus for producing a sand casting mold or the like comprising an intermediate storage room for receiving an amount of molding compound sufficient to shape a casting mold, a charging chamber defined by a pattern, pattern support and molding box, a means for air-tight closure of the charging chamber, a device for producing a pressure substantially below atmospheric pressure within the charging chamber and an operable closure for connecting the intermediate storage room with the charging chamber to feed the molding material to the charging chamber, wherein the intermediate storage room is in the form of a pressure lock and on its charging side is provided with an air-tight closure, and that both the compacting chamber receiving the conventionally constructed molding box and the intermediate storage room, via connecting means, are connectible to the device for generating a pressure which is substantially reduced with respect to the atmospheric pressure, both when the closure is closed and when it is open.
Dependencies are inferred from the claim text.