US4591472A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of blanks
Assignee: Keramik Holding AG Laufen
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Filing: 1983-03-08
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Granted: 1986-05-27
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Expires: 2003-03-08
Abstract
Abstract The invention relates to a process for the mass-production conversion of an inorganic and/or organic material, containing a liquid fraction of between 3 and 90% by weight, to a blank by means of core casting and/or hollow casing, the material being introduced into a cavity located between at least two porous mould portions and being dewatered in contact with the adjacent mould portions.
Inventors
- 👤 Thomas Gerster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:24
CPC Classifications
B; B28; B28B; B28B1/00; B28B1/26; B28B1/261; B28B1/265
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
208 words
A method for the production of blanks by processing slip, consisting of an inorganic and/or organic material having a liquid fraction of between 3 and 90% by weight, by means of core casting and/or hollow casting, comprising the steps of (a) introducing slip into a mould cavity of a mould, the mould including at least two mould portions formed of porous plastic material and having a plurality of blind holes distributed in a pattern over each mould portion, being adjoined at the side opposite to the mould cavity by a system of channels connected to the open ends of the blind holes, introducing of slip via an inlet channel into the mould cavity under an initial pressure of between 0.1 and 3 bar, and by simultaneously displacing air and residual liquid if present, from the mould cavity into the porous material of the mould portions (b) applying increased pressure of between 10 to 50 bar onto the slip contained in the mould cavity by simultaneously displacing liquid from the slip into the porous material of the mould portions and into blind holes as well as the system of channels, respectively, and (c) maintaining that increased pressure until the slip is solidificated at least up to a certain degree.
Claim 2
Independent Claim
208 words
A method for the production of blanks by processing slip, consisting of an inorganic and/or organic material having a liquid fraction of between 3 and 90% by weight, by means of core casting and/or hollow casting, comprising the steps of (a) introducing slip into a mould cavity of a mould, the mould including at least two mould portions formed of porous plastic material and having a plurality of blind holes distributed in a pattern over each mould portion, being adjoined at the side opposite to the mould cavity by a system of channels connected to the open ends of the blind holes, introducing of slip via an inlet channel into the mould cavity under an initial pressure of between 0.1 and 3 bar, and by simultaneously displacing air and residual liquid if present, from the mould cavity into the porous material of the mould portions (b) applying increased pressure of between 10 to 50 bar onto the slip contained in the mould cavity by simultaneously displacing liquid from the slip into the porous material of the mould portions and into blind holes as well as the system of channels, respectively, and (c) maintaining that increased pressure until the slip is solidificated at least up to a certain degree.
Claim 3
Dependent Claim
83 words
A method according to claim 1 wherein during an initial phase of the application of increased pressure the liquid which is displaced into the porous material of the mould portions is drained via the blind holes and the system of channels and thereafter a counter pressure is applied to the mould portions via the channels and blind holes, in order to temporarily accumulate part of the liquid at least in the boundary layer of the mould portions adjacent to the mould cavity surfaces.
Claim 4
Dependent Claim
59 words
The method according to claim 2 for manufacturing a hollow casting blank or a combined hollow and core casting blank wherein after a certain solidification of the slip at the mould cavity surfaces, liquid-containing residual material from the inner walls of the blank cavity is blown out and thereafter a gas pressure is built up in this blank cavity.
Claim 5
Dependent Claim
20 words
A method according to claim 3 wherein the build-up of gas pressure within said blank cavity is repeated several times.
Claim 6
Dependent Claim
53 words
A method according to claim 4 wherein the liquid present in the mould cavity boundary layer is held in this layer on the mould cavity side by balanced interaction of this gas pressure with gas or liquid pressure acting via the system of channels and via the blind holes on both mould portions.
Claim 7
Dependent Claim
53 words
A method according to claim 4 wherein the liquid present in the mould cavity boundary layer is held in this layer on the mould cavity side by balanced interaction of this gas pressure with gas or liquid pressure acting via the system of channels and via the blind holes on both mould portions.
Claim 8
Dependent Claim
26 words
A method according to claim 5 wherein the residual slip or blank cavity slip remaining after the formation of the blank is re-used without additional processing.
Claim 9
Dependent Claim
33 words
A method according to claim 3 wherein for building up said gas pressure, compressed air is used which is introduced into the said blank cavity through the inlet channel in the mould portions.
Claim 10
Dependent Claim
34 words
A method according to claim 4 wherein for building up the said gas pressure, compressed air is used which is introduced into the said blank cavity through the inlet channel in the mould portions.
Claim 11
Dependent Claim
84 words
A method according to claim 1, wherein external pressure means which hold the two mould portions tightly together during and after the introduction of the slip is released in different phases, insofar as a low letting-down and initial opening speed infinitely adjustable within the speed range of 0-10 mm/second being progressively changed to a rapid fast speed, as soon as, as a function of the conicity and depth of the blank, the clearance between the mould portions, necessary for trouble-free opening, has been reached.
References Cited (Backward Citations)
US1340308A
Cited
US1692887A
Cited
US3225414A
Cited
US3634559A
Cited
US3536799A
Cited
US3663681A
Cited
US3958908A
Cited
US4320080A
Cited
US4413966A
Cited
DE3319012A1
Cited
GB2124540A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-26 | 1989-11-25 | 1990-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-26 | 1993-11-25 | 1994-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-26 | 1997-11-25 | 1998-05-27 | $7700.00 | Window Closed / Lapsed |