Sand vibration and compaction apparatus and method

A sand molding compaction unit comprising:

• a frame having a vertical axis and shaped so that the center of gravity of the frame falls on the vertical axis;
• means for resiliently connecting the frame to a rigid support, to permit limited horizontal and vertical oscillation of the frame relative to the support;
• a sand molding flask rigidly supported within the frame and shaped such that the center of gravity of the flask when filled with sand lies within the frame substantially on the frame vertical axis;
• first vibrator means for generating an oscillating force vector on the frame along a first horizontal axis passing through the center of gravity of the flask;
• second vibrator means for generating an oscillating force vector on the frame along a second horizontal axis orthogonal to the first axis, passing through the center of gravity of the flask;
• third vibrator means for generating an oscillating force vector on the frame along said vertical axis;
• and
• means for independently controlling the magnitude and duration of the force vectors generated by the first, second and third vibrator means.

A molding apparatus comprising:

• a rigid mold flask adapted to contain a mold pattern and sand;
• a rectangular frame including means for selectively rigidly connecting the frame to the flask;
• means for resiliently mounting the frame to a rigid support;
• a first pair of motors, each motor having a drive shaft for rotation about a shaft axis and a weight mounted for eccentric rotation about the shaft axis, the pair of motors being coupled to the frame for movement with the frame;
• and
• first means for synchronizing the motors in counter rotation whereby the rotation of the eccentric weights produces a first force vector normal to the imaginary center line passing through the shafts of the first pair of motors, in a direction diagonally across opposed corners of the frame.

A method of compacting filler material between a container and an object in the container during the operation of a production line system, comprising the steps of:

• vibrating a frame at a low, idle speed;
• positioning the container in the frame and connecting the frame to the container while the frame is vibrating at idle speed;
• positioning the object within the container;
• depositing filler material into the container;
• at a preselected point during the idle speed vibration of the frame increasing the vibration speed of the frame in accordance with a preestablished net force vector sequence to compact the filler material around the object;
• reducing the vibration speed of the frame to said idle speed;
• disconnecting the container from the frame and removing the container and object therein from the frame while the frame is vibrating at idle speed;
• and
• repeating the foregoing steps until all containers have been filled and compacted.

A method of operating a sand molding compaction system having a plurality of substantially identical rigid mold flasks, each adapted to contain a substantially identical mold pattern and sand, the frame including means for selectively rigidly connecting the frame to at least one of the flasks, means resiliently mounting the frame to a rigid support, at least one pair of motors coupled to the frame for movement with the frame, and means for synchronizing the motors to produce an oscillating net force vector acting on the flask, comprising the steps of:

• (a) disconnecting and removing a first flask from the frame;
• (b) operating all the motors in synchronized phase relationship at low speed to drive the frame slowly with an idle net vector;
• (c) rigidly connecting a second flask to the frame while the frame is driven slowly by the idle vector;
• (d) positioning a pattern in sand within the second flask;
• (e) operating each motor pair in synchronized phase relationship in a predetermined sequence of high speeds to generate at least one net compaction vector on the frame, for compacting the sand around the pattern in the second flask;
• (f) operating all the motors in synchronized phase relationship at low speed to drive the frame slowly;
• (g) disconnecting and removing the second flask and contained pattern from the frame while the frame is driven in accordance with step (f);
• and
• (h) repeating steps (b) - (g) successively with each of the remaining flasks and patterns.