Method and apparatus for producing casting moulds or mould parts
AssigneeDisa Industries A/S
InventorJan Bechmann Johansen
Life of this patent
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Abstract
In a mould forming machine comprising a moulding chamber, a movable squeeze plate and a pattern, the filling of selected parts of the pattern with compressible mould material is improved by applying vacuum to said selected parts. By applying the vacuum separately to different parts of the pattern at different periods, of time during the filling step, the vacuum application can be applied during shorter periods only when needed, thereby reducing the drying out of the mould material and reducing the amounts of air to be removed by the vacuum system.
Claims14
Method of producing casting moulds or mould parts in a mould forming machine comprising at least one moulding chamber with at least one movable squeeze plate and at least one pattern, said method comprising the steps of:
- a) filling the at least one moulding chamber with compressible mould material,
- b) applying a vacuum at selected parts of the at least one pattern during said filling step,
- c) pressing the mould material by moving the at least one squeeze plate, and
- d) removing the produced mould or mould parts from the at least one moulding chamber, making the at least one moulding chamber ready for a new cycle starting from the filling step,
- said method being characterized by further comprising the steps of
- b1) applying said vacuum to at least two different parts of the at least one pattern at different periods of time during said filling step.
Apparatus for producing casting moulds or mould parts, comprising
- at least one moulding chamber with at least one movable squeeze plate and at least one pattern,
- filling means adapted to introduce compressible mould material into the at least one moulding chamber, and
- a vacuum source selectively connectable to passages leading to selected parts of the at least one pattern
- characterized by further comprising
- means for selectively connecting said vacuum source to at least two different parts of the at least one pattern, said different parts being located at different levels at each pattern that the different parts are filled with mould material during different time intervals, said means for selectively connecting said vacuum source comprising separate valves connected to said at least two different parts of the at least one pattern and said valves being opened and closed at different points of time.
Dependencies are inferred from the claim text.