Method of producing foundry moulds and cores
Abstract
Abstract A method of producing foundry moulds and cores comprising the steps of preparing a mixture containing a moulding sand, an ingredient chosen from the group which consists of ligno sulphonate of an alkali, alkali-earth metal, ammonium and their mixture as a binder, a material containing aluminate of an alkali metal as a hardener and water, making moulds and cores from said mixture and weathering to harden. The material containing aluminate of an alkali metal is an intermediate product obtainable in the production of aluminum oxide from bauxite or nepheline ores. According to the invention the foundry moulds and cores can be manufactured of a fluid moulding mixture containing a foaming agent apart from said ingredients. To enhance the strength of the moulds and cores the mixture can also contain a water-binding addition, such as cement or carbamide.
Inventors
- 👤 V Bortnik
- 👤 I Korenbljum
- 👤 N Kagan
- 👤 J Razumeev
- 👤 Z Usuboy
- 👤 V Kuznetsov
- 👤 A Lyass
- 👤 P Borsuk
Bibliographic Details
Claims Analysis
Total Claims: 4References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-15 | 1977-10-15 | 1978-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-15 | 1981-10-15 | 1982-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-15 | 1985-10-15 | 1986-04-16 | $7700.00 | Window Closed / Lapsed |