Bearing system for a sand container to be vibrated in a lost foam casting apparatus

{
  "publication_number": "US6575614B2",
  "country": "US",
  "kind": "B2",
  "title": "Bearing system for a sand container to be vibrated in a lost foam casting apparatus",
  "abstract": "Bearing members project upwardly from a vibrating table with frusto-conical surfaces tapering upwardly to engage in corresponding frusto-conical sockets disposed in the bottom of a container of sand to be compacted. The frusto-conical sockets are formed of a material resistant to wear. The bearing members each comprise a body of wearable material which forms the frusto-conical surface. Each wearable body is fixed to the vibrating table by a respective releasable fastening element elongated in a vertical direction and having an upper head shaped to transmit and distribute a compression pre-load into the body.",
  "claims": [
    "1. A bearing system for a sand container to be vibrated on a vibrating table in a lost foam casting installation, the system comprising: a plurality of bearing members projecting upwardly from the vibrating table, each bearing member having an upwardly tapered frusto-conical surface; a corresponding plurality of frusto-conical bearing sockets on the bottom of the container; wherein the frusto-conical sockets are formed in a material resistant to wear; and wherein the bearing members each comprise a body of wearable material which forms said frusto-conical surface, secured to the vibrating table by means of a respective releasable fastening element elongated in an essentially vertical direction and having an upper head shaped to transmit and distribute a compression pre-load into the body.",
    "2. The system of claim 1, wherein the bearing member has an upper base surface and the fastening element has a head of downwardly tapered conical shape with an upper base with a width less than but comparable to a width of the upper base surface of the bearing member.",
    "3. The system of claim 1, wherein a passage is formed, in correspondence with each bearing member, for conveying a stream of air into the region between the socket and the upper surface of the bearing member.",
    "4. The system of claim 3, wherein the passages extend through the bearing members.",
    "5. The system of claim 4, wherein the passages are formed in the fastening elements.",
    "6. The system of claim 1, further including a plurality of rigid reinforcement elements which extend vertically in the wearable body of each bearing member.",
    "7. The system of claim 6, wherein the reinforcement elements are distributed regularly throughout the wearable body.",
    "8. The system of claim 1, wherein the fastening element comprises a bolt co-operating with a locking nut disposed under a plate removably mounted on the vibrating table.",
    "9. The system of claim 1, wherein the sockets on the bottom of the container are formed of tempered steel.",
    "10. The system of claim 9, wherein each of the sockets is formed in an insert of tempered steel fixed to the bottom of the container.",
    "11. The system of claim 1, wherein the body of each bearing member is made of a material including polyether-ether-ketone.",
    "12. The system of claim 1, wherein an elastic element is disposed between the vibrating table and each fastening element to stress said fastening element in tension."
  ],
  "description_excerpt": "The present invention relates to a bearing system for a sand container to be vibrated on a vibrating table in a lost foam casting apparatus. In particular, the invention relates to a bearing system for a sand container to be vibrated on a vibrating table in a lost foam casting installation, the system comprising a plurality of bearing members projecting upwardly from the vibrating table, each bearing member having an upwardly tapered frusto-conical surface, and a corresponding plurality of frusto-conical bearing sockets on the bottom of the container. A bearing system of this type is described in U.S. Pat. No. 4,859,070.\n\nAs is known, the lost foam casting technique is a foundry technique based essentially on the production of a polystyrene (or similar material) pattern which reproduces the characteristics of the piece to be made. The pattern is introduced into a container filled with sand which, by means of vibration, is distributed and compacted in such a way as intimately to closely reproduce the shape of the pattern. Subsequently, hot casting material (typically molten metal) is poured into the space occupied by the pattern. The casting material dissolves the pattern and occupies the space previously occupied thereby within the sand. The final result is a casting, and thus a workpiece, the shape of which copies exactly the shape of the pattern.",
  "cpc": [
    "B22C 15/10",
    "B22C 9/04"
  ],
  "ipc": [
    "B22C 15/10",
    "B22C 9/04"
  ],
  "assignees": [
    "Fata Group SpA"
  ],
  "inventors": [
    "Bartolomeo Tosco",
    "Luigi Villani"
  ],
  "filing_date": "2001-05-08",
  "publication_date": "2003-06-10",
  "grant_date": "2003-06-10",
  "priority_date": "2000-05-09",
  "application_number": "US-85016901-A",
  "family_id": "8175321",
  "cited_by_count": 79,
  "citations": [
    "US4299692A",
    "US4600046A",
    "US4859070A",
    "US5067549A",
    "JPH05309445A",
    "US6149292A"
  ]
}