US3713475A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shell molds
Assignee: ChampionX LLC
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Filing: 1971-01-04
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Granted: 1973-01-30
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Expires: 1991-01-04
Abstract
Abstract A shell mold characterized by a slip coat and an overlying stucco coat is dried by immersing the shell thus prepared in a fluidized bed of desiccant, whereafter the bed is collapsed to invest the shell with the desiccant.
Inventors
- 👤 H Roelofs
- 👤 W Lafferty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:20
CPC Classifications
B; B22; B22C; B22C9/00; B22C9/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
96 words
In the construction of multi-layered shell molds surrounding an expendible pattern, where each layer of the shell is represented by a slip coat interior and a stucco coat exterior applied to the slip, the method of drying each layer after application of the stucco coat by immersing the shell in a fluidized bed of a desiccant, collapsing the bed of desiccant about the shell and holding the bed collapsed for a predetermined period of time during which the desiccant absorb water from the slip coat, and thereafter re-fluidizing the bed of desiccant and withdrawing the shell.
Claim 2
Dependent Claim
96 words
In the construction of multi-layered shell molds surrounding an expendible pattern, where each layer of the shell is represented by a slip coat interior and a stucco coat exterior applied to the slip, the method of drying each layer after application of the stucco coat by immersing the shell in a fluidized bed of a desiccant, collapsing the bed of desiccant about the shell and holding the bed collapsed for a predetermined period of time during which the desiccant absorb water from the slip coat, and thereafter re-fluidizing the bed of desiccant and withdrawing the shell.
Claim 3
Dependent Claim
29 words
A method according to claim 1 where the desiccant in the bed is a material selected from the group consisting of silica gel, alumina, calcium sulfate and phosphorous pentoxide.
Claim 4
Dependent Claim
40 words
A method according to claim 2 wherein the slip coat is composed of aqueous colloidal silica having silica particles suspended therein and wherein the stucco coat is a material selected from the group consisting of silica, zircon and alumina-silicate compound.
Claim 5
Dependent Claim
108 words
In the construction of multi-layered shell molds surrounding an expendible pattern, where each layer of the shell is represented by a slip coat interior and a stucco coat exterior applied to the slip, the method of drying each layer after application of the stucco coat by surrounding the shell layer with a body of particulate desiccant presented by a fluidized bed of the desiccant, providing relative movement between the shell and the body of desiccant as a whole to drive the particles of desiccant into the pores of the stucco coat, and thereafter withdrawing from the fluidized bed the shell containing particles of desiccant in the pores thereof.
Claim 6
Dependent Claim
108 words
In the construction of multi-layered shell molds surrounding an expendible pattern, where each layer of the shell is represented by a slip coat interior and a stucco coat exterior applied to the slip, the method of drying each layer after application of the stucco coat by surrounding the shell layer with a body of particulate desiccant presented by a fluidized bed of the desiccant, providing relative movement between the shell and the body of desiccant as a whole to drive the particles of desiccant into the pores of the stucco coat, and thereafter withdrawing from the fluidized bed the shell containing particles of desiccant in the pores thereof.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |