| 摘要 |
<p>Disclosed is an apparatus and a method for heatless production of hollow items, such as foundry shell cores from the mixture of granular mineral and synthetic binder, as provided by the principal process described in the U.S. patent application Serial No. 022,170, now U.S. Patent No. 4,232,726 issued November 11, 1980. Two permeable-to-gas patterns form an inner cavity of desirable configuration and are enclosed by non-permeable halves of the pattern box, forming an outer cavity or flow space. The pattern box is mounted on two plates Or the rotatable cage assembly, selectively positionable in at least three positions: charge, discharge, and transfer. Above the pattern box are pivotally mounted material supply means, sealing means, and a trimmer. Below the pattern box is a receiver of an airless conveyor for recirculation of the discharged unhardened material. The pattern box is connected to two manifolds: one for consecutive supply of catalyst gas and the compressed air, another for exhaust and venting. After material has been blown with the help of compressed air from the material supply means into the pattern inner cavity, it is sealed and the air is flushed out of the system by compressed catalyst gas introduced into the pattern box fox about one second. Said gas then penetrates to desirable depth into material's outer layer starting polymerization and curing of its binder. After a few seconds, unsealed pattern box assembly is turned upside down and compressed air is blown into the pattern box, dislodging unhardened portion of the material out of the inside of the produced shell-like product. Consequently, the pattern box is opened and the product is transferred from the apparatus to a suitable place outside the machine. The production process has nine basic steps, and the cycle of the apparatus comprises twenty-four (24) operations completely mechanized and performed within approximately thirty seconds.</p> |
