US3979196A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the hot-working of glass
Assignee: US Philips Corp
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Filing: 1975-11-17
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Granted: 1976-09-07
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Expires: 1995-11-17
Abstract
Abstract The undulation of hot-moulded glass is avoided when the cooling of the glass edge layers in the first phase of the moulding operation is delayed and is accelerated after completed moulding. This is achieved by using a mould of a glassy carbon having a porous structure. Prior to the moulding, the pores are filled with a gas-forming liquid or a gas. The resulting gas film between the glass and the surface of the mould is removed ater completed moulding. The pores may subsequently be filled with a cooling agent.
Inventors
- 👤 Berthold Frank
- 👤 Bernhard Lersmacher
- 👤 Hans-Jurgen Lydtin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:46
CPC Classifications
C; C03; C03B; C03B9/00; C03B9/30; C03B9/38; C03B9/3875; C03B40/00; C03B40/02; C03B40/04; C03B9/29; C03B9/292; C03B9/3808; C03B9/3841; C03B9/48
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
115 words
A method for the hot-working of glass by means of a mould which consists of glassy carbon at least at its surface contacting the heated glass, characterized in that the glassy carbon of the mould used has a porous structure, in which pore size and pore density (pore distribution) are adjusted so that during the moulding process the glass cannot penetrate into the surface, and the pores are accessible from the side of the mould remote from the heated glass, that prior to the moulding the pores are filled with a gas-forming liquid or a gas, and the resulting gas film between the glass and the surface of the mould is removed after completed moulding.
Claim 2
Independent Claim
115 words
A method for the hot-working of glass by means of a mould which consists of glassy carbon at least at its surface contacting the heated glass, characterized in that the glassy carbon of the mould used has a porous structure, in which pore size and pore density (pore distribution) are adjusted so that during the moulding process the glass cannot penetrate into the surface, and the pores are accessible from the side of the mould remote from the heated glass, that prior to the moulding the pores are filled with a gas-forming liquid or a gas, and the resulting gas film between the glass and the surface of the mould is removed after completed moulding.
Claim 3
Dependent Claim
34 words
A method as claimed in claim 1, characterized in that the porous, glassy carbon used has an average pore diameter of 0.1 to 2mm and a density of approximately 0.2 to 1.2g/cm 3 .
Claim 4
Dependent Claim
28 words
A method as claimed in claim 1 characterized in that the gas-forming liquid is water or oil and the gas is selected from water vapour and oil vapour.
Claim 5
Dependent Claim
23 words
A method as claimed in claim 1 characterized in that after removing the gas film the pores are filled with a cooling agent.
Claim 6
Dependent Claim
28 words
A method as claimed in claim 4, characterized in that the cooling agent is introduced in the porous mould at an elevated pressure after the actual moulding process.
Claim 7
Dependent Claim
18 words
A method as claimed in claim 1 characterized in that the mould used is composed of several parts.
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) | 1979-09-07 | 1980-03-08 | 1980-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-07 | 1984-03-08 | 1984-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-07 | 1988-03-08 | 1988-09-07 | $7700.00 | Window Closed / Lapsed |