DE276557C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

PATENT LETTERING

- M 276557 CLASS 31c. GROUP

In the case of machine processing of the molding sand, it has been common practice to date to use the individual Sand types, after they have been brought to the desired grain size and sieved, in suitable mixing devices: premixers, mixing drums or long, with troughs provided with a number of moving knives, to be combined and mixed. On the one hand, these mixing devices require a fairly large one for their installation Base area and, on the other hand, their power consumption is very high and they are also useful very quickly in the company.

According to the invention, all these disadvantages are avoided in that several Sand types necessary for the composition of the desired molding sand mixture, in particular Used sand and new sand, are simultaneously passed through a communal sieving and mixing device and Mix during preparation. There is a special sieve drum for each type of sand present, and the goods passing through the sieves fall on a communal item Mixing plate, so that it is partly already while entering the mixing device mixed up and on the other hand is laid on top of each other in such thin layers that the types of sand are completely mixed will. This results in a great simplification in the structure of the apparatus and a considerable cheaper and faster work.

An exemplary embodiment of the subject matter of the invention is shown in the drawing.

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Fig. Ι is a vertical section,

Fig. 2 is a plan view.

In a closed housing 2 are two polygonal, in opposite directions rotating sieve drums 4 and 6 attached next to each other. Both screening drums have separate feed hoppers 8, 10 and drainage channels for the residues 12, 14 are provided. At a certain distance is one of the drums known per se, rotating around its vertical axis 18 Plate 16 is mounted, above which a fixed transverse arm 20 is likewise known with attached sliders 22, 24 is attached. There is a discharge funnel on the outer edge 26 provided. Above the middle of the table is a funnel 28 with a feed roller 30, the one with coal dust is charged. The sand can be used either moist or dry. It It is also possible to add the required liquid additives through a tube 32 or the like. The mixing plate to feed.

The operation of this device is as follows: The sieve 4 is made by hand or a mechanical feed device is charged with used sand and the sieve 6 in a corresponding manner Way with new sand. The screenings penetrating the walls as the screens circulate falls onto the rotating ones Mixing plate 16. As soon as the material to be sieved falls onto this plate, a Mixing takes place, which is now completed by the agitator. The sieve residues arrive to cleaning or shredding devices

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gen and are then automatically fed back to the sieves.

Instead of the polygonal sieves shown, you can also use vibrating sieves, an endless mixing belt can also be used instead of the rotating mixing table Use wisely. The screens can also be placed one above the other or one inside the other.

Claims (2)

Patent Claims: i. Automatic preparation and mixing device for molding sand, characterized in that two separate screening devices (4, 6) for several Sand types of sand partially mix their screenings immediately after it emerges and in this condition on a common one Drop stirrer (16, 22, 24) to complete mixing. 2. Apparatus according to claim i, characterized characterized in that the sieve drums are stored over a common plate with agitators are. 1 sheet of drawings.