US3789909A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dip casting method using transpirationally cooled mold having relieved impervious outer layer
Assignee: Motors Liquidation Co
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Filing: 1972-11-07
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Granted: 1974-02-05
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Expires: 1992-11-07
Abstract
Abstract In a dip casting process, a die is provided having a porous metal body, an impervious outer layer, a relieved surface on the outer layer and mold cavity in the porous body opening through the outer layer. The relieved surface provides a plurality of peaks/ridges for limited area contact with the melt. In operation, air is blown through the porous metal and out the porous walls of the mold cavity to cool them, and the impervious layer is heated to a temperature where casting metal will not adhere to the surface after the die leaves the melt. Shallow die immersion in the melt limits melt contact to the peaks/ridges on the surface thereby precluding any substantial chilling of the melt on the surface.
Inventors
- 👤 O Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:57
CPC Classifications
B; B22; B22D; B22D25/00; B22D25/02; B22D25/04; B22D11/00; B22D11/06; B22D11/0611; B22D11/0614
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
183 words
A process for forming intricate, thin-sectioned castings from a metal melt comprising the steps of: a. providing a die comprising a porous metal body, an impervious, low thermally conductive layer on the body and a mold cavity in said body opening through said layer, said layer having a relieved outer surface comprising a plurality of peaks and valleys; b. passing a cooling gas through said porous metal body and out the walls of said cavity to cool the cavity walls below the solidification temperature of said melt-metal; c. shallowly immersing the thusly prepared die into said melt to a depth where said melt contacts only said peaks to thereby rapidly heat said peaks to a melt-metal-shedding temperature without extracting a substantial quantity of heat from said melt through said layer; d. applying a vacuum to said porous metal body to suck melt into said cavity; e. removing the die from the melt and shedding any melt-metal from said outer surface of the layer to carry away from the melt only metal solidified in said cavity; and f. stripping the casting from the cavity.
Claim 2
Dependent Claim
183 words
A process for forming intricate, thin-sectioned castings from a metal melt comprising the steps of: a. providing a die comprising a porous metal body, an impervious, low thermally conductive layer on the body and a mold cavity in said body opening through said layer, said layer having a relieved outer surface comprising a plurality of peaks and valleys; b. passing a cooling gas through said porous metal body and out the walls of said cavity to cool the cavity walls below the solidification temperature of said melt-metal; c. shallowly immersing the thusly prepared die into said melt to a depth where said melt contacts only said peaks to thereby rapidly heat said peaks to a melt-metal-shedding temperature without extracting a substantial quantity of heat from said melt through said layer; d. applying a vacuum to said porous metal body to suck melt into said cavity; e. removing the die from the melt and shedding any melt-metal from said outer surface of the layer to carry away from the melt only metal solidified in said cavity; and f. stripping the casting from the cavity.
Claim 3
Dependent Claim
204 words
A process for forming intricate, thin-sectioned age-hardenable, lead-acid storage battery grids from a lead alloy melt comprising the steps of: a. providing a die comprising a porous metal body, an impervious, low thermally conductive layer on the body and a mold cavity in said body opening through said layer, said layer having a relieved outer surface comprising a plurality of peaks and valleys; b. passing a cooling gas through said porous metal body and out the walls of said cavity to cool the cavity walls below the solidification temperature of the melt; c. shallowly immersing the thusly prepared die into said melt to a depth where said melt contacts only said peaks to thereby rapidly heat said peaks to a melt-metal-shedding temperature without extracting a substantial quantity of heat from said melt through said layer; d. applying a vacuum to said porous metal body to suck melt into said cavity; e. quenching said lead alloy in said cavity; f. removing the die from the melt and shedding any melt-metal from said surface to carry away from the melt only metal solidified in said cavity; g. stripping the thusly formed grid from the cavity; and h. allowing the thusly formed grid to age and strengthen.
Claim 4
Dependent Claim
204 words
A process for forming intricate, thin-sectioned age-hardenable, lead-acid storage battery grids from a lead alloy melt comprising the steps of: a. providing a die comprising a porous metal body, an impervious, low thermally conductive layer on the body and a mold cavity in said body opening through said layer, said layer having a relieved outer surface comprising a plurality of peaks and valleys; b. passing a cooling gas through said porous metal body and out the walls of said cavity to cool the cavity walls below the solidification temperature of the melt; c. shallowly immersing the thusly prepared die into said melt to a depth where said melt contacts only said peaks to thereby rapidly heat said peaks to a melt-metal-shedding temperature without extracting a substantial quantity of heat from said melt through said layer; d. applying a vacuum to said porous metal body to suck melt into said cavity; e. quenching said lead alloy in said cavity; f. removing the die from the melt and shedding any melt-metal from said surface to carry away from the melt only metal solidified in said cavity; g. stripping the thusly formed grid from the cavity; and h. allowing the thusly formed grid to age and strengthen.
Claim 5
Dependent Claim
90 words
A dip casting die comprising: a. a porous metal body adapted to be transpirationally cooled; b. an impervious, low thermally conductive layer on the body said layer having a relieved outer surface comprising a plurality of peaks and valleys adapted to prevent casting metal from filling the valleys under shallow immersion conditions; c. a mold cavity having porous walls in said body opening through said layer; and d. means for introducing cooling gas into said porous metal body for exiting through and transpirationally cooling the porous walls of said cavity.
Claim 6
Dependent Claim
90 words
A dip casting die comprising: a. a porous metal body adapted to be transpirationally cooled; b. an impervious, low thermally conductive layer on the body said layer having a relieved outer surface comprising a plurality of peaks and valleys adapted to prevent casting metal from filling the valleys under shallow immersion conditions; c. a mold cavity having porous walls in said body opening through said layer; and d. means for introducing cooling gas into said porous metal body for exiting through and transpirationally cooling the porous walls of said cavity.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |