US3717693A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dry pressing ceramic disk in mold having a multi-part female die
Assignee: Primerica Inc
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Filing: 1971-03-15
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Granted: 1973-02-20
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Expires: 1991-03-15
Abstract
Abstract A method for forming a uniformly compacted ceramic dish having at least one angled sidewall comprising the use of a multiple section female die having a dish-shaped mold designed to produce a dish with a sidewall having a thinner upper edge and a slight foot at its base. One or more bottom, intermediate, movable, sidewall punches are employed in the die to obtain a more uniform fill and a more uniform compaction ratio.
Inventors
- 👤 L Kohl
- 👤 D Shea
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:46
CPC Classifications
B; B28; B28B; B28B3/00; B28B3/02; B28B3/08; B28B3/083
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
220 words
A method of pressing a uniformly compacted, green, ceramic dish having at least one angled sidewall comprising: providing a die designed to produce a dish having at least one angled sidewall, said sidewall having a thinner upper edge anD a slight foot at its base, said die comprising a reciprocable top punch and a bottom mold comprising an exterior lower punch, an interior reciprocable lower punch and at least one intermediate reciprocable lower punch incorporated in the sidewall area, said reciprocable lower punches being movable with respect to the exterior lower punch and each other; raising the reciprocable lower punches, prior to charging of the mold, to their up positions, wherein the highest point of each successively interior lower punch is higher than the lowest point of an adjacent, exterior, lower punch, whereby the lower punches are placed in a stepped arrangement; charging a mixture of ceramic raw materials comprising 4 to 25 percent by weight water into said die; and pressing said mixture by lowering said top punch relative to said exterior lower punch, by lowering said intermediate movable lower punch relative to said exterior lower punch, and by lowering said interior movable lower punch relative to said intermediate movable lower punch, to form said dish having sufficient wet strength to retain its shape during removal from said die.
Claim 2
Independent Claim
220 words
A method of pressing a uniformly compacted, green, ceramic dish having at least one angled sidewall comprising: providing a die designed to produce a dish having at least one angled sidewall, said sidewall having a thinner upper edge anD a slight foot at its base, said die comprising a reciprocable top punch and a bottom mold comprising an exterior lower punch, an interior reciprocable lower punch and at least one intermediate reciprocable lower punch incorporated in the sidewall area, said reciprocable lower punches being movable with respect to the exterior lower punch and each other; raising the reciprocable lower punches, prior to charging of the mold, to their up positions, wherein the highest point of each successively interior lower punch is higher than the lowest point of an adjacent, exterior, lower punch, whereby the lower punches are placed in a stepped arrangement; charging a mixture of ceramic raw materials comprising 4 to 25 percent by weight water into said die; and pressing said mixture by lowering said top punch relative to said exterior lower punch, by lowering said intermediate movable lower punch relative to said exterior lower punch, and by lowering said interior movable lower punch relative to said intermediate movable lower punch, to form said dish having sufficient wet strength to retain its shape during removal from said die.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein all sidewalls of said dish are angled.
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) | 1976-02-20 | 1976-08-21 | 1977-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-20 | 1980-08-21 | 1981-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-20 | 1984-08-21 | 1985-02-20 | $7700.00 | Window Closed / Lapsed |