Apparatus for preparing foundry molds or cores from cold quick setting sand/binder/catalyst mixtures

Claim 2

Apparatus for preparing foundry moulds or cores from cold quick-setting sand/binder/catalyst mixtures comprising a mixing chamber, supply means for providing the mixing chamber with separate charges of sand and binder on the one hand and sand and catalyst on the other hand, a mechanical mixing element in the mixing chamber, an outlet from the mixing chamber for passing material by gravity from the mixing chamber into a blowing chamber, means for moving the mixing chamber and the blowing chamber apart to allow the final mixture to be discharged from the blowing chamber into a mould or core box and to allow the mixing chamber to be purged and purging means for the mixing chamber.

Claim 3

Apparatus according to claim 1 wherein the mixing chamber is movable between a first position in which it is adapted to deliver the mixed material to the blowing chamber, and a second position in which the mixing chamber is adapted to be purged by said purging means.

Claim 4

Apparatus according to claim 1 wherein the blowing chamber is movable between a first position in which it is adapted to receive the final mixture from the mixing chamber, and a second position in which the final mixture can be discharged into the mould or core box.

Claim 5

Apparatus according to claim 1 wherein said purging means comprises means for supplying gas to the chamber.

Claim 6

Apparatus according to claim 1 wherein the mixing chamber comprises a vertical cylindrical wall, a base wall with an outlet therein and a vertical axis rotary mixing element in the chamber, the element comprising a pair of angle iron members tangentially mounted to said axis and having rigid blades attached thereto adapted to sweep the base wall and a pair of spring steel blades angularly offset from said pair of angle iron members adapted to sweep the vertical wall.

Claim 7

Apparatus according to claim 5 wherein said second pair of blades are fixedly attached to a cross member which also serves to sweep a roof of the mixing chamber.

Claim 8

Apparatus according to claim 6 wherein the outlet of the mixing chamber is offset from an inlet of the mixing chamber through 270* in a direction of rotation of the rotary mixing element.

Claim 9

Apparatus according to claim 7 wherein the outlet of the mixing chamber is provided with a time controlled outlet valve adapted to close the outlet during a mixing operation and to open the outlet after a predetermined time interval for discharging the final mixture into the blowing chamber.

Claim 10

Apparatus according to claim 8 wherein metered amounts of said separate charges are intermixed in the mixing chamber in separate batches for a time interval of 10 seconds.

Claim 11

Apparatus according to claim 1 wherein the mixing chamber comprises a vertical cylindrical wall, a base wall with an outlet therein and a vertical axis rotary mixing element in the chamber, the outlet comprising a pair of angle iron members tangentially mounted to said axis and having rigid blades attached thereto adapted to sweep the base wall and a pair of spring steel blades angularly offset from said pair of angle iron members adapted to sweep the vertical wall, the mixing chamber having an inlet, the outlet of the mixing chamber being offset from the inlet through 270* in a direction of rotation of the rotary mixing element and wherein the outlet of the mixing chamber is permanently open so that the material in the mixing chamber is intermixed by the rotary mixing element as said material is passed substantially straight through the mixing chamber and into the blowing chamber.

Claim 12

Apparatus according to claim 10 wherein the rotary mixing element is rotated at a speed of 120 RPM.

Claim 13

Apparatus according to claim 1 wherein the mixing chamber comprises a vertical cylindrical wall which is provided with tangentially disposed ports for connection to a source of said cleaning means to purge any material remaining in the mixing chamber, after discharge of the final mixture, into a suitable receptacle.