Patent US3774668A successfully refreshed from Google Patents.
US3774668A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum casting apparatus
Assignee: Sulzer AG
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Filing: 1971-03-19
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Granted: 1973-11-27
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Expires: 1991-03-19
Abstract
Abstract A mold core and a mold casting are positioned to define a mold cavity and the melt of the material is drawn into the cavity under vacuum. The vacuum can be eliminated after the melt in the cavity has solidified about the melt entrance openings leading into the cavity or can be maintained to some degree to draw off gases. The resulting casting can be of any shape and, where annular, can be used to make piston rings.
Inventors
- 👤 J Heimgartner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:02
CPC Classifications
B; B22; B22D; B22D18/00; B22D18/06; B22D27/00; B22D27/08
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
130 words
A vacuum casting apparatus comprising a mold chamber having a mold cavity therein, at least one opening in said chamber communicating said mold cavity with the exterior of said chamber for introducing a melt of casting material into said mold cavity, a sprue extending from said opening, means for evacuating said mold cavity to draw the casting material through said opening into said mold cavity, means for moving said chamber and the melt relative to each other to immerse said opening in said melt, and a U-shaped tube disposed in and extending from said sprue to provide a substantially unhindered rising of the casting material in the mold chamber, said tube further being adapted to hydrostatically prevent a back flow of casting material from said mold cavity after filling thereof.
Claim 2
Dependent Claim
130 words
A vacuum casting apparatus comprising a mold chamber having a mold cavity therein, at least one opening in said chamber communicating said mold cavity with the exterior of said chamber for introducing a melt of casting material into said mold cavity, a sprue extending from said opening, means for evacuating said mold cavity to draw the casting material through said opening into said mold cavity, means for moving said chamber and the melt relative to each other to immerse said opening in said melt, and a U-shaped tube disposed in and extending from said sprue to provide a substantially unhindered rising of the casting material in the mold chamber, said tube further being adapted to hydrostatically prevent a back flow of casting material from said mold cavity after filling thereof.
Claim 3
Dependent Claim
128 words
A vacuum casting apparatus comprising a mold chamber having a mold cavity therein, at least one opening in said chamber communicating said mold cavity with the exterior of said chamber for introducing a melt of casting material into said mold cavity, a sprue extending from said opening, means for evacuating said mold cavity to draw the casting material through said opening into said mold cavity, means for moving said chamber and the melt relative to each other to immerse said opening in said melt, and a ball valve disposed in said sprue to provide a substantially unhindered rising of the casting material in the mold chamber, said ball valve further being adapted to hydrostatically prevent a back flow of casting material from said mold cavity after filling thereof.
Claim 4
Dependent Claim
128 words
A vacuum casting apparatus comprising a mold chamber having a mold cavity therein, at least one opening in said chamber communicating said mold cavity with the exterior of said chamber for introducing a melt of casting material into said mold cavity, a sprue extending from said opening, means for evacuating said mold cavity to draw the casting material through said opening into said mold cavity, means for moving said chamber and the melt relative to each other to immerse said opening in said melt, and a ball valve disposed in said sprue to provide a substantially unhindered rising of the casting material in the mold chamber, said ball valve further being adapted to hydrostatically prevent a back flow of casting material from said mold cavity after filling thereof.
Claim 5
Dependent Claim
36 words
A casting apparatus as set forth in claim 2 wherein said ball valve includes a seat and a ball located above said seat and being of a weight greater than its bouyancy in the casting material.
Claim 6
Dependent Claim
36 words
A casting apparatus as set forth in claim 2 wherein said ball valve includes a seat and a ball located below said seat and being of a weight less than its bouyancy in the casting material.
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) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |