Method and apparatus for evaporative pattern casting

A method for inserting an evaporative pattern of an object to be cast into a container and providing an unbound molding medium into the container and around the pattern comprising the steps of:

• inserting the pattern into the container;
• and
• supplying the unbound molding medium into the container and around the pattern;
• said step of supplying comprising vibrating partial volumes of substantially the whole volume of said container in sequential order as said container is being filled until the unbound molding medium fills said container and forms an upper surface therein, said step of vibrating partial volumes comprising at least vibrating substantially each of said partial volumes one at a time whereby, during at least part of the supplying step, substantially only one of said partial volumes is vibrated at a time.

A method for producing a casting by the evaporative pattern casting process in unbound molding medium within a container, said method comprising the steps of:

• inserting a pattern to be gasified on contact with molten metal of an object to be cast into the container;
• disposing unbound molding medium around the pattern and compacting said molding medium by vibrating the container in defined subvolumes of the total volume of the container, said step of vibrating comprising at least vibrating substantially each of said defined subvolumes one at a time whereby, during at least part of the disposing step, substantially only one of said defined subvolumes is vibrated at a time;
• displacing the pattern with molten metal to form a casting;
• allowing the casting so formed to cool;
• fluidizing the packed unbound molding medium by providing gas into said container;
• gripping said casting with a movable set of jaws;
• and
• pulling said casting out of said fluidized unbound molding medium.

Apparatus for forming evaporative pattern castings comprising:

• means for inserting a pattern to be gasified on contact with molten metal of an object to be cast into a container;
• means for supplying an unbound molding medium into said container and disposing said molding medium around said pattern in a time period, said means for disposing comprising means for dispensing said molding medium into said container and means for compacting said molding medium around said pattern in predetermined partial volumes of substantially the total volume of said container, said means for compacting comprising means for at least compacting substantially each of said predetermined partial volumes of substantially the total volume of said container one at a time whereby, during at least part of the time period, substantially only one of said partial volumes is compacted at a time;
• means for displacing said pattern with molten metal thereby forming a metal casting and releasing gaseous material from the evaporation of said pattern;
• and
• means for removing the casting, once cooled, from said container.

Apparatus for inserting an evaporative pattern of an object to be cast into a container and providing an unbound molding medium into the container and around the pattern comprising:

• means for inserting the pattern into the container;
• and
• means for supplying the unbound molding medium into the container and around the pattern in a time period;
• said means for supplying comprising means for vibrating partial volumes of substantially the whole volume of said container in a sequential order as said container is being filled until the container is filled and the unbound molding medium forms an upper surface therein, said means for vibrating comprising means for at least vibrating substantially each of said partial volumes one at a time whereby, during at least part of the time period, substantially only one of said partial volumes is vibrated at a time.

Apparatus for producing a casting by the evaporative pattern casting process in unbound molding medium within a container, said apparatus comprising:

• means for inserting a pattern to be gasified on contact with molten metal of an object to be cast into the container;
• means for disposing unbound molding medium around the pattern in a time period and for compacting the molding medium by vibrating the container in defined subvolumes of the total volume of the container, said means for compacting comprising means for at least vibrating the container substantially in each defined subvolume one at a time whereby, during at least part of the time period, substantially only one of said defined subvolumes is vibrated at a time;
• means for displacing the pattern with molten metal to form a casing;
• means for allowing the casting so formed to cool;
• means for fluidizing said packed unbound molding medium by providing gas into said container;
• and
• means for gripping said casting and pulling said casting out of said fluidized unbound molding medium.

A method for evaporative pattern casting comprising the steps of:

• inserting a pattern of an object to be cast and adapted to be gasified on contact with molten metal into a container;
• supplying an unbound molding medium into said container and disposing said molding medium around said pattern, said step of disposing comprising dispensing said molding medium into said container and compacting said molding medium around said pattern in predetermined partial volumes of substantially the whole volume of said container;
• providing a cover on said container, rotating said container after said container has been completely filled and compacting said container during said step of rotating;
• displacing said pattern in said compacted molding medium with molten metal thereby forming a metal casting and releasing gaseous material from the evaporation of said pattern;
• allowing the casting to cool;
• and
• removing the casting from said container.

A method for inserting an evaporative pattern of an object to be cast into a container and providing an unbound molding medium into the container and around the pattern comprising the steps of:

• inserting the pattern into the container;
• and
• supplying the unbound molding medium into the container and around the pattern;
• said step of supplying comprising vibrating partial volumes of substantially the whole volume of said container in sequential order as the container is being filled until the unbound molding medium fills said container and forms an upper surface therein;
• and further comprising the step of
• covering said filled container with means for filling any space above the upper surface of said unbound molding medium and for providing a retaining pressure against said surface;
• rotating said filled container and vibrating the partial volumes of said container in predefined sequential order to compact further said molding medium and allow said molding medium to flow into any cavities in said pattern;
• and
• after compaction, returning said container to an upright position.

Apparatus for forming evaporative pattern castings comprising:

• means for inserting a pattern to be gasified on contact with molten metal of an object to be cast into a container;
• means for supplying an unbound molding medium into said container and disposing said molding medium around said pattern, said means for disposing comprising means for dispensing said molding medium into said container and means for compacting said molding medium around said pattern in predetermined partial volumes of substantially the total volume of said container;
• cover means for clamping to the top of said container;
• means for rotating said container after said container has been completely filled and covered;
• said means for compacting further comprising means for compacting said container during said rotation;
• means for displacing said pattern with molten metal thereby forming a metal casting and releasing gaseous material from the evaporation of said pattern;
• and
• means for removing the casting once cooled from said container.

Apparatus for inserting an evaporative pattern of an object to be cast into a container and providing an unbound molding medium into the container and around the pattern comprising:

• means for inserting the pattern into the container;
• means for supplying the unbound molding medium into the container and around the pattern;
• said means for supplying comprising means for vibrating partial volumes of substantially the whole volume of said container in a sequential order as said container is being filled until the container is filled and the unbound molding medium forms an upper surface therein;
• means for covering said filled container and for filling any space above the upper surface of said unbound molding medium and for providing a retaining pressure against said surface;
• means for rotating said filled container, said means for vibrating further vibrating the partial volumes of said container in predefined sequential order to further compact said molding medium and allow said molding medium to flow into any cavities in said pattern;
• and
• means for returning said container to an upright position after compaction.