Making moulds
AssigneeBOC Limited
InventorStephen N. Waldron
Life of this patent
Estimating the term…
Abstract
In the manufacture of moulds or mould cores, refractory sand, a resin binder and a catalyst are passed into a mixer to form a free-flowing mixture from which the moulds or mould cores are made. As the sand is fed into the mixer it is cooled by contact with an atmospheric gas in liquid or solid state or the cold vapor of such a gas so as to keep the temperature of the sand as it enters the mixer below that at which the resin cures. To enable the sand to be delivered below a chosen temperature from a quarry to a foundry where the sand is used, the sand after quarrying and drying is fluidized by air, an atmospheric gas in liquid or solid state being introduced into the fluidizing air so as to lower its temperature.
Claims9
In a method of making moulds which comprises the steps of
- supplying sand, a resin binder and a catalyst to a mixing device to form a free flowing mixture of sand, resin binder and catalyst;
- supplying said mixture to a mould station without substantial curing of said resin binder;
- and
- forming moulds in said mould station;
- the improvement comprising:
- feeding sand through a separate conduit to said mixing device;
- sensing the temperature of said sand in said conduit;
- introducing a flow of cryogenic liquid into said conduit to contact said sand and reduce the temperature thereof as it is being fed upon sensing said temperature above a predetermined value only a few degrees centigrade below that at which curing of the resin binder takes place in the mixing device;
- and
- controlling the flow of said cryogenic liquid in response to said sensed temperature so that the temperature of said sand is reduced to said predetermined value upon being fed into said mixing device.
Apparatus for making moulds comprising a conduit;
- means for feeding sand through said conduit;
- a mixing device adapted to receive sand fed through said conduit;
- means for supplying resin binder and catalyst to said mixing device;
- means for sensing the temperature of said sand in said conduit;
- means for introducing a flow of cryogenic liquid into said conduit to contact and reduce the temperature of said sand as it is being fed therethrough upon sensing said sand temperature above a predetermined value only a few degrees centigrade below that at which curing of the resin binder takes place in the mixing device;
- means for controlling the flow of said cryogenic liquid in response to said sensed temperature such that said sand is received in said mixing device at said predetermined value whereby said mixing device is effective to form a free flowing mixture of said sand, resin binder and catalyst;
- means for forming moulds and means for supplying said free flowing mixture to said mould forming means.
Dependencies are inferred from the claim text.