US4785870A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Evaporative pattern casting process
Assignee: Ashland LLC
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Filing: 1987-08-28
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Granted: 1988-11-22
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Expires: 2007-08-28
Abstract
Abstract An improved expendable pattern casting process and an improved refractory composition for coating expendable patterns used in the process containing substantially spherical refractory material.
Inventors
- 👤 Robert L. Snook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:08
CPC Classifications
B; B22; B22C; B22C7/00; B22C7/02; B22C7/023
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
92 words
In the process for the preparation of metallic castings by the evaporative pattern casting process wherein an expendable pattern is coated with refractory material prior to the pouring of molten metal to form a casting of the desired shape an improvement comprising coating the expendable pattern with refractory material comprising a sufficient amount of substantially spherical refractory material to support the pattern during the pouring of the metal and to vent the gases formed by the evaporation of the pattern so as to obtain a casting of the desired shape and surface.
Claim 2
Dependent Claim
92 words
In the process for the preparation of metallic castings by the evaporative pattern casting process wherein an expendable pattern is coated with refractory material prior to the pouring of molten metal to form a casting of the desired shape an improvement comprising coating the expendable pattern with refractory material comprising a sufficient amount of substantially spherical refractory material to support the pattern during the pouring of the metal and to vent the gases formed by the evaporation of the pattern so as to obtain a casting of the desired shape and surface.
Claim 3
Dependent Claim
14 words
The process of claim 1 wherein the expendable pattern is made of expandable polystyrene.
Claim 4
Dependent Claim
21 words
The process of claim 1 wherein the refractory material comprises, at least, about 10 percent by volume substantially spherical refractory material.
Claim 5
Dependent Claim
23 words
The process of claim 1 wherein the refractory material comprises from about 10 to about 80 percent by volume substantially spherical refractory material.
Claim 6
Dependent Claim
13 words
The process of claim 1 wherein the substantially spherical refractory material is hollow.
Claim 7
Dependent Claim
14 words
The process of claim 1 wherein the refractory material is composed of aluminum silicate.
Claim 8
Dependent Claim
30 words
The process of claim 1 wherein more than one coating of the refractory material is applied to the surface of the pattern prior to the pouring of the molten metal.
Claim 9
Dependent Claim
82 words
A process of the preparation of a casting by the evaporative pattern casting procedure which comprises forming a pattern of the desired article from vaporizable material, coating the pattern with a refractory material comprising, at least, 10 percent by volume of substantially spherical refractory material to allow venting of vapors of the vaporizable material, placing the coated pattern in unbonded sand and pouring molten metal into the coated pattern causing the vaporization of the pattern and the formation of the desired casting.
Claim 10
Dependent Claim
82 words
A process of the preparation of a casting by the evaporative pattern casting procedure which comprises forming a pattern of the desired article from vaporizable material, coating the pattern with a refractory material comprising, at least, 10 percent by volume of substantially spherical refractory material to allow venting of vapors of the vaporizable material, placing the coated pattern in unbonded sand and pouring molten metal into the coated pattern causing the vaporization of the pattern and the formation of the desired casting.
Claim 11
Dependent Claim
14 words
The process of claim 8 wherein the expendable pattern is made of expandable polystyrene.
Claim 12
Dependent Claim
16 words
The process of claim 8 wherein the refractory material substantially consists of substantially spherical shaped material.
Claim 13
Dependent Claim
23 words
The process of claim 8 wherein the refractory material comprises from about ten to about 80 percent by volume substantially spherical refractory material.
Claim 14
Dependent Claim
13 words
The process of claim 8 wherein the substantially spherical refractory material is hollow.
Claim 15
Dependent Claim
14 words
The process of claim 8 wherein the refractory material is composed of aluminum silicate.
Claim 16
Dependent Claim
30 words
The process of claim 8 wherein more than one coating of the refractory material is applied to the surface of the pattern prior to the pouring of the molten metal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-22 | 1992-05-23 | 1992-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-22 | 1996-05-23 | 1996-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-22 | 2000-05-23 | 2000-11-22 | $7700.00 | Window Closed / Lapsed |