US4388097A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hot-pressed fluoride glasses
Assignee: The AT&T MVPD Group LLC
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Filing: 1981-05-28
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Granted: 1983-06-14
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Expires: 2001-05-28
Abstract
Abstract Hot pressing of fluoride glasses is provided. These glasses are synthesized from ZrF 4 -BaF 2 and HfF 4 -BaF 2 systems. Hot pressing rough blanks in a closed die made of hard, polished, optically-figured material, such as cobalt-bonded tungsten carbide, is done by pressing the glasses at a temperature between that of the softening point of the glass and its crystallization temperature and at a pressure sufficient to cause flow of the glass at the pressing temperature. As a consequence, mechanical polishing steps on all glass surfaces is eliminated, thereby minimizing surface contamination.
Inventors
- 👤 Roger R. Turk
- 👤 Morton Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:39
CPC Classifications
C; C03; C03B; C03B11/00; C03B11/06; C03B11/08; C03B11/088; C03B19/00; C03B19/06; C03B19/09; C03C; C03C3/00; C03C3/32; C03C3/325; C03B2201/00; C03B2201/80; C03B2201/82; C03B2215/00; C03B2215/40; C03B2215/44; Y; Y10; Y10S; Y10S65/00; Y10S65/15; Y10S65/16
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
130 words
A process for hot-pressing two or more pieces of a fluoride glass or powder thereof to consolidate and form a unitary piece, said fluoride glass having a composition comprising about 47 to 62 mole percent of at least one component selected from the group consisting of HfF 4 and ZrF 4 , about 23 to 38 mole percent of BaF 2 and up to about 15 mole percent of at least one component selected from the group consisting of ThF 4 and LaF 3 , the process comprising pressing the fluoride glass at a temperature ranging from the softening point of the glass to just below the crystallization temperature of the glass and at a pressure which is at least sufficient to cause flow of the glass at that temperature.
Claim 2
Dependent Claim
130 words
A process for hot-pressing two or more pieces of a fluoride glass or powder thereof to consolidate and form a unitary piece, said fluoride glass having a composition comprising about 47 to 62 mole percent of at least one component selected from the group consisting of HfF 4 and ZrF 4 , about 23 to 38 mole percent of BaF 2 and up to about 15 mole percent of at least one component selected from the group consisting of ThF 4 and LaF 3 , the process comprising pressing the fluoride glass at a temperature ranging from the softening point of the glass to just below the crystallization temperature of the glass and at a pressure which is at least sufficient to cause flow of the glass at that temperature.
Claim 3
Dependent Claim
76 words
The process of claim 1 in which the glass composition is one selected from the group consisting of (a) 60 mole percent ZrF 4 , 33 mole percent BaF 2 and 7 mole percent ThF 4 ; (b) 60 mole percent HfF 4 , 33 mole percent BaF 2 and 7 mole percent ThF 4 ; and (c) 60 mole percent HfF 4 , 33 mole percent BaF 2 and 7 mole percent LaF 3 .
Claim 4
Dependent Claim
15 words
The process of claim 1 in which the temperature is at least about 300° C.
Claim 5
Dependent Claim
16 words
The process of claim 1 in which the pressure ranges from about 1,500 to 4,000 psi.
Claim 6
Dependent Claim
50 words
The process of claim 1 in which up to about 10 mole percent of at least one of ThF 4 and LaF 3 is replaced by at least one component selected from the group consisting of rare earth fluorides, UF 4 , AlF 3 , KF, CsF, NaF and RbF.
Claim 7
Dependent Claim
129 words
A process for forming an optical component which comprises pressing two or more pieces of a fluoride glass or powder thereof to consolidate and form a unitary piece at a temperature ranging from the softening point of the glass to just below the crystallization temperature of the glass and at a pressure which is at least sufficient to cause flow of the glass at that temperature, the fluoride glass having a composition comprising about 47 to 62 mole percent of at least one component selected from the group consisting of HfF 4 and ZrF 4 , about 23 to 38 mole percent of BaF 2 and up to about 15 mole percent of at least one component selected from the group consisting of ThF 4 and LaF 3 .
Claim 8
Dependent Claim
129 words
A process for forming an optical component which comprises pressing two or more pieces of a fluoride glass or powder thereof to consolidate and form a unitary piece at a temperature ranging from the softening point of the glass to just below the crystallization temperature of the glass and at a pressure which is at least sufficient to cause flow of the glass at that temperature, the fluoride glass having a composition comprising about 47 to 62 mole percent of at least one component selected from the group consisting of HfF 4 and ZrF 4 , about 23 to 38 mole percent of BaF 2 and up to about 15 mole percent of at least one component selected from the group consisting of ThF 4 and LaF 3 .
Claim 9
Dependent Claim
76 words
The process of claim 6 in which the glass composition is one selected from the group consisting of (a) 60 mole percent ZrF 4 , 33 mole percent BaF 2 and 7 mole percent ThF 4 ; (b) 60 mole percent HfF 4 , 33 mole percent BaF 2 and 7 mole percent ThF 4 ; and (c) 60 mole percent HfF 4 , 33 mole percent BaF 2 and 7 mole percent LaF 3 .
Claim 10
Dependent Claim
15 words
The process of claim 6 in which the temperature is at least about 300° C.
Claim 11
Dependent Claim
16 words
The process of claim 6 in which the pressure ranges from about 1,500 to 4,000 psi.
Claim 12
Dependent Claim
50 words
The process of claim 6 in which up to about 10 mole percent of at least one of ThF 4 and LaF 3 is replaced by at least one component selected from the group consisting of rare earth fluorides, UF 4 , AlF 3 , KF, CsF, NaF and RbF.
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) | 1986-06-13 | 1986-12-13 | 1987-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-13 | 1990-12-13 | 1991-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-13 | 1994-12-13 | 1995-06-14 | $7700.00 | Window Closed / Lapsed |