US3844755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for transfer molding glass lenses
Assignee: Eastman Kodak Co
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Filing: 1972-11-16
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Granted: 1974-10-29
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Expires: 1992-11-16
Abstract
Abstract A method and apparatus for molding of glass into finished optical elements wherein optical glass is placed in a transfer chamber formed of a glasslike carbon material and is subjected to heat and pressure. The softened glass is transferred through a sprue into a mold cavity formed of the same glasslike carbon material. The walls defining the mold cavity and the transfer chamber have high surface quality and high surface accuracy, and the mold cavity is configured to produce optical elements of predetermined shapes.
Inventors
- 👤 G Blair
- 👤 C Maier
- 👤 M Angle
- 👤 G Bender
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:38
CPC Classifications
C; C03; C03B; C03B19/00; C03B19/02; C03B19/025; C03B11/00; C03B11/005; C03B11/06; C03B11/08; C03B11/084; C03B11/086; C03B11/12; C03B11/122; C03B2215/00; C03B2215/02; C03B2215/08; C03B2215/14; C03B2215/24; C03B2215/66; C03B2215/71; C03B2215/80
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
76 words
A METHOD OF MOLDING GLASS COMPRISING THE STEPS OF: PROVIDING SURFACES OF GLASSLIKE CARBON, THE GLASSLIKE CARBON BEING A FORM OF CARBON WHICH HAS BEEN PREPARED BY THE THERMAL DEGRADATION OF AN ORGANIC POLYMER, WHICH IS SUBSTANTIALLY CHEMICALLY INERT WITH HEATED GLASS, AND WHICH IS ISOTROPIC, AND THE SURFACES DEFINING A TRANSFER CHAMBER AND AT LEAST ONE MOLD CAVITY AND THE SURFACES FURTHER DEFINING AT LEAST ONE SPRUE CONNECTING THE TRANSFER CHAMBER AND THE MOLD CAVITY;
Claim 2
Independent Claim
76 words
A METHOD OF MOLDING GLASS COMPRISING THE STEPS OF: PROVIDING SURFACES OF GLASSLIKE CARBON, THE GLASSLIKE CARBON BEING A FORM OF CARBON WHICH HAS BEEN PREPARED BY THE THERMAL DEGRADATION OF AN ORGANIC POLYMER, WHICH IS SUBSTANTIALLY CHEMICALLY INERT WITH HEATED GLASS, AND WHICH IS ISOTROPIC, AND THE SURFACES DEFINING A TRANSFER CHAMBER AND AT LEAST ONE MOLD CAVITY AND THE SURFACES FURTHER DEFINING AT LEAST ONE SPRUE CONNECTING THE TRANSFER CHAMBER AND THE MOLD CAVITY;
Claim 3
Independent Claim
120 words
A method of molding glass comprising the steps of: providing surfaces of glasslike carbon, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, and the surfaces defining a transfer chamber and mold cavities and the surfaces further defining sprues connecting the transfer chamber and the mold cavities; placing glass within the transfer chamber; pre-heating the surfaces and the glass; establishing a non-oxidizing atmosphere around the surfaces and the glass; heat softening the glass; and applying pressure to the heat softened glass until the glass is transferred from the transfer chamber through the sprues into the mold cavities.
Claim 4
Independent Claim
120 words
A method of molding glass comprising the steps of: providing surfaces of glasslike carbon, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, and the surfaces defining a transfer chamber and mold cavities and the surfaces further defining sprues connecting the transfer chamber and the mold cavities; placing glass within the transfer chamber; pre-heating the surfaces and the glass; establishing a non-oxidizing atmosphere around the surfaces and the glass; heat softening the glass; and applying pressure to the heat softened glass until the glass is transferred from the transfer chamber through the sprues into the mold cavities.
Claim 5
Independent Claim
150 words
A method of molding glass comprising the steps of: providing surfaces of glasslike carbon, the surfaces defining a transfer chamber and mold cavities and the surfaces further defining sprues connecting the transfer chamber and the mold cavities, and the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic; placing glass within the transfer chamber; heat softening the glass; applying pressure to the heat softened glass until the glass in the transfer chamber is transferred through the sprues into the mold cavity; cooling the surfaces and glass while applying pressure to the glass remaining within the transfer chamber until the temperature of the glass has been reduced below the transformation temperature of the glass; and removing the force from the glass and further cooling the surfaces and the glass.
Claim 6
Independent Claim
150 words
A method of molding glass comprising the steps of: providing surfaces of glasslike carbon, the surfaces defining a transfer chamber and mold cavities and the surfaces further defining sprues connecting the transfer chamber and the mold cavities, and the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic; placing glass within the transfer chamber; heat softening the glass; applying pressure to the heat softened glass until the glass in the transfer chamber is transferred through the sprues into the mold cavity; cooling the surfaces and glass while applying pressure to the glass remaining within the transfer chamber until the temperature of the glass has been reduced below the transformation temperature of the glass; and removing the force from the glass and further cooling the surfaces and the glass.
Claim 7
Independent Claim
165 words
A method of molding glass comprising the steps of: providing surfaces of glasslike carbon, the surfaces defining a transfer chamber and mold cavities and the surfaces further defining sprues connecting the transfer chamber and the mold cavities, and the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic; placing glass within the transfer chamber; preheating the surfaces and the glass; establishing a non-oxidizing atmosphere around the surfaces and the glass; heat softening the glass; applying pressure to the heat softened glass until the glass in the transfer chamber is transferred through the sprues into the mold cavity; cooling the surfaces and the glass while applying pressure to the glass remaining within the transfer chamber until the temperature of the glass has been reduced below the transformation temperature of that glass; and removing the force from the glass and further cooling the mold members.
Claim 8
Independent Claim
165 words
A method of molding glass comprising the steps of: providing surfaces of glasslike carbon, the surfaces defining a transfer chamber and mold cavities and the surfaces further defining sprues connecting the transfer chamber and the mold cavities, and the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic; placing glass within the transfer chamber; preheating the surfaces and the glass; establishing a non-oxidizing atmosphere around the surfaces and the glass; heat softening the glass; applying pressure to the heat softened glass until the glass in the transfer chamber is transferred through the sprues into the mold cavity; cooling the surfaces and the glass while applying pressure to the glass remaining within the transfer chamber until the temperature of the glass has been reduced below the transformation temperature of that glass; and removing the force from the glass and further cooling the mold members.
Claim 9
Independent Claim
127 words
A method of molding glass comprising the steps of: providing a mold assembly including a transfer chamber, a mold cavity and a sprue, the transfer chamber, the mold cavity and the sprue being defined by glasslike carbon surfaces, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, and the sprue connecting the transfer chamber and the mold cavity; placing glass in the transfer chamber; applying heat to the mold assembly until the glass has been heat softened; applying pressure to the glass in the transfer chamber until the glass has been transferred through the sprue into the mold cavity; and removing the molded glass.
Claim 10
Independent Claim
127 words
A method of molding glass comprising the steps of: providing a mold assembly including a transfer chamber, a mold cavity and a sprue, the transfer chamber, the mold cavity and the sprue being defined by glasslike carbon surfaces, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, and the sprue connecting the transfer chamber and the mold cavity; placing glass in the transfer chamber; applying heat to the mold assembly until the glass has been heat softened; applying pressure to the glass in the transfer chamber until the glass has been transferred through the sprue into the mold cavity; and removing the molded glass.
Claim 11
Independent Claim
145 words
A method of molding glass comprising the steps of: providing a mold assembly including a transfer chamber, a mold cavity and a sprue, the transfer chamber, the mold cavity and the sprue being defined by glasslike carbon surfaces, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, and the sprue connecting the transfer chamber and the mold cavity; placing glass in the transfer chamber; preheating the mold assembly and the glass; establishing a non-oxidizing atmosphere around the mold assembly and the glass; applying heat to the mold assembly until the glass has been heat softened; applyiNg pressure to the glass in the transfer chamber until the glass has been transferred through the sprue into the mold cavity; and removing the molded glass.
Claim 12
Independent Claim
145 words
A method of molding glass comprising the steps of: providing a mold assembly including a transfer chamber, a mold cavity and a sprue, the transfer chamber, the mold cavity and the sprue being defined by glasslike carbon surfaces, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, and the sprue connecting the transfer chamber and the mold cavity; placing glass in the transfer chamber; preheating the mold assembly and the glass; establishing a non-oxidizing atmosphere around the mold assembly and the glass; applying heat to the mold assembly until the glass has been heat softened; applyiNg pressure to the glass in the transfer chamber until the glass has been transferred through the sprue into the mold cavity; and removing the molded glass.
Claim 13
Independent Claim
169 words
A method of molding glass comprising the steps of: providing a mold assembly including a transfer chamber, a mold cavity and a sprue, the transfer chamber, the mold cavity and the sprue being defined by glasslike carbon surfaces, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, and the sprue connecting the transfer chamber and the mold cavity; placing glass in the transfer chamber; applying heat to the mold assembly until the glass has been heat softened; applying pressure to the glass in the transfer chamber until the glass has been transferred through the sprue into the mold cavity; cooling the mold assembly while applying pressure to the glass remaining within the transfer chamber until the temperature of the glass has been reduced below the transformation temperature of that glass; removing pressure from the glass and further cooling the mold assembly; and removing the molded glass.
Claim 14
Independent Claim
169 words
A method of molding glass comprising the steps of: providing a mold assembly including a transfer chamber, a mold cavity and a sprue, the transfer chamber, the mold cavity and the sprue being defined by glasslike carbon surfaces, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, and the sprue connecting the transfer chamber and the mold cavity; placing glass in the transfer chamber; applying heat to the mold assembly until the glass has been heat softened; applying pressure to the glass in the transfer chamber until the glass has been transferred through the sprue into the mold cavity; cooling the mold assembly while applying pressure to the glass remaining within the transfer chamber until the temperature of the glass has been reduced below the transformation temperature of that glass; removing pressure from the glass and further cooling the mold assembly; and removing the molded glass.
Claim 15
Independent Claim
187 words
A method of molding glass comprising the steps of: providing a mold assembly including a transfer chamber, a mold cavity and a sprue, the transfer chamber, the mold cavity and the sprue being defined by glasslike carbon surfaces, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, and the sprue connecting the transfer chamber and the mold cavity; placing glass in the transfer chamber; preheating the mold assembly and the glass; establishing a non-oxidizing atmosphere around the mold assembly and the glass; applying heat to the mold assembly until the glass has been heat softened; applying pressure to the glass in the transfer chamber until the glass has been transferred through the sprue into the mold cavity; cooling the mold assembly while applying pressure to the glass remaining within the transfer chamber until the temperature of the glass has been reduced below the transformation temperature of that glass; removing pressure from the glass and further cooling the mold assembly; and removing the molded glass.
Claim 16
Independent Claim
187 words
A method of molding glass comprising the steps of: providing a mold assembly including a transfer chamber, a mold cavity and a sprue, the transfer chamber, the mold cavity and the sprue being defined by glasslike carbon surfaces, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, and the sprue connecting the transfer chamber and the mold cavity; placing glass in the transfer chamber; preheating the mold assembly and the glass; establishing a non-oxidizing atmosphere around the mold assembly and the glass; applying heat to the mold assembly until the glass has been heat softened; applying pressure to the glass in the transfer chamber until the glass has been transferred through the sprue into the mold cavity; cooling the mold assembly while applying pressure to the glass remaining within the transfer chamber until the temperature of the glass has been reduced below the transformation temperature of that glass; removing pressure from the glass and further cooling the mold assembly; and removing the molded glass.
Claim 17
Independent Claim
172 words
A method of molding glass comprising the steps of: providing a plurality of mold members that are relatively movable between open and closed positions, the mold members defining a transfer chamber and further defining, when in their closed positions, mold cavities and sprues connecting the transfer chamber and the mold cavities, the transfer chamber, the mold cavities and the sprues being defined by surfaces of glasslike carbon, and the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic; placing glass within the transfer chamber; moving the mold members to their closed positions; heat softening the glass at a temperature within the range of 700*C to 800*C; applying a pressure within the range of 50 psi to 5,000 psi to the glass within the transfer chamber until the glass is transferred through the sprues into the mold cavities; moving the mold members to their open positions; and removing the molded glass.
Claim 18
Independent Claim
172 words
A method of molding glass comprising the steps of: providing a plurality of mold members that are relatively movable between open and closed positions, the mold members defining a transfer chamber and further defining, when in their closed positions, mold cavities and sprues connecting the transfer chamber and the mold cavities, the transfer chamber, the mold cavities and the sprues being defined by surfaces of glasslike carbon, and the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic; placing glass within the transfer chamber; moving the mold members to their closed positions; heat softening the glass at a temperature within the range of 700*C to 800*C; applying a pressure within the range of 50 psi to 5,000 psi to the glass within the transfer chamber until the glass is transferred through the sprues into the mold cavities; moving the mold members to their open positions; and removing the molded glass.
Claim 19
Independent Claim
205 words
A method of molding glass comprising the steps of: providing a plurality of mold members that are relatively movable between open and closed positions, the mold members defining a transfer chamber and further defining, when in their closed positions, mold cavities and sprues connecting the transfer chamber and the mold cavities, the transfer chamber, the mold cavities and the sprues being defined by surfaces of Glasslike carbon, and the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic; placing glass within the transfer chamber; moving the mold members to their closed positions; preheating the glass and the mold members to a temperature within the range of 200*C to 300*C; establishing an atmosphere of 95% nitrogen and 5% hydrogen around the mold members and the glass; heat softening the glass at a temperature within the range of 700C to 800*C; applying a pressure within the range of 50 psi to 5,000 psi to the glass within the transfer chamber until the glass is transferred through the sprues into the mold cavities; moving the mold members to their open positions; and removing the molded glass.
Claim 20
Independent Claim
205 words
A method of molding glass comprising the steps of: providing a plurality of mold members that are relatively movable between open and closed positions, the mold members defining a transfer chamber and further defining, when in their closed positions, mold cavities and sprues connecting the transfer chamber and the mold cavities, the transfer chamber, the mold cavities and the sprues being defined by surfaces of Glasslike carbon, and the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic; placing glass within the transfer chamber; moving the mold members to their closed positions; preheating the glass and the mold members to a temperature within the range of 200*C to 300*C; establishing an atmosphere of 95% nitrogen and 5% hydrogen around the mold members and the glass; heat softening the glass at a temperature within the range of 700C to 800*C; applying a pressure within the range of 50 psi to 5,000 psi to the glass within the transfer chamber until the glass is transferred through the sprues into the mold cavities; moving the mold members to their open positions; and removing the molded glass.
Claim 21
Independent Claim
207 words
A method of molding glass comprising the steps of: providing a plurality of mold members that are relatively movable between open and closed positions, the mold members defining a transfer chamber and further defining, when in their closed positions, mold cavities and sprues connecting the transfer chamber and the mold cavities, the transfer chamber, the mold cavities and the sprues being defined by surfaces of glasslike carbon, and the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic; placing glass within the transfer chamber; heat softening the glass at a temperature within the range of 700*C to 800*C; applying a pressure within the range of 50 psi to 5,000 psi to the glass within the transfer chamber until the glass is transferred through the sprues into the mold cavities; cooling the mold members to a temperature within the range of 550*C to 600*C while maintaining the pressure on the glass remaining in the transfer chamber; removing the pressure on the glass and cooling the mold members to a temperature of approximately 300*C; moving the mold members to their open positions; and removing the molded glass.
Claim 22
Independent Claim
207 words
A method of molding glass comprising the steps of: providing a plurality of mold members that are relatively movable between open and closed positions, the mold members defining a transfer chamber and further defining, when in their closed positions, mold cavities and sprues connecting the transfer chamber and the mold cavities, the transfer chamber, the mold cavities and the sprues being defined by surfaces of glasslike carbon, and the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic; placing glass within the transfer chamber; heat softening the glass at a temperature within the range of 700*C to 800*C; applying a pressure within the range of 50 psi to 5,000 psi to the glass within the transfer chamber until the glass is transferred through the sprues into the mold cavities; cooling the mold members to a temperature within the range of 550*C to 600*C while maintaining the pressure on the glass remaining in the transfer chamber; removing the pressure on the glass and cooling the mold members to a temperature of approximately 300*C; moving the mold members to their open positions; and removing the molded glass.
Claim 23
Independent Claim
248 words
A method of molding glass comprising the steps of: providing a plurality of mold members that are relatively movable between open and closed positions, the mold members defining a transfer chamber and further defining, when in their closed positions, mold cavities and sprues connecting the transfer chamber and the mold cavities, the transfer chamber, the mold cavities and the sprues being defined by walls of glasslike carbon, and the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic; placing glass within the transfer chamber; moving the mold members to their closed positions; preheating the glass and the mold members to a temperature within the range of 200*C to 300*C; establishing an atmosphere of 95% nitrogen and 5% hydrogen around the mold members and the glass; heat softening the glass at a temperature within the range of 700*C to 800*C; applying a pressure within the range of 50 psi to 5,000 psi to the glass within the transfer chamber until the glass is transferred through the sprues into the mold cavities; cooling the mold members to a temperature within the range of 550*C to 600*C while maintaining the pressure on the glass remaining in the transfer chamber; removing the pressure on the glass and cooling the mold members to a temperature of approximately 300*C; moving the mold members to their open positions; and removing the molded glass.
Claim 24
Independent Claim
248 words
A method of molding glass comprising the steps of: providing a plurality of mold members that are relatively movable between open and closed positions, the mold members defining a transfer chamber and further defining, when in their closed positions, mold cavities and sprues connecting the transfer chamber and the mold cavities, the transfer chamber, the mold cavities and the sprues being defined by walls of glasslike carbon, and the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic; placing glass within the transfer chamber; moving the mold members to their closed positions; preheating the glass and the mold members to a temperature within the range of 200*C to 300*C; establishing an atmosphere of 95% nitrogen and 5% hydrogen around the mold members and the glass; heat softening the glass at a temperature within the range of 700*C to 800*C; applying a pressure within the range of 50 psi to 5,000 psi to the glass within the transfer chamber until the glass is transferred through the sprues into the mold cavities; cooling the mold members to a temperature within the range of 550*C to 600*C while maintaining the pressure on the glass remaining in the transfer chamber; removing the pressure on the glass and cooling the mold members to a temperature of approximately 300*C; moving the mold members to their open positions; and removing the molded glass.
Claim 25
Dependent Claim
142 words
Apparatus for molding glAss comprising: a plurality of mold members having open and closed positions and formed of glasslike carbon, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, said mold members defining a transfer chamber and further defining, when in their closed positions, mold cavities and sprues connecting said transfer chamber and said mold cavities; means for supporting said mold members and for moving said mold members between their open and closed positions; means for heating said mold members above the softening point of glass contained within said transfer chamber; and means for applying pressure to softened glass contained within said transfer chamber to transfer the glass from said transfer chamber through said sprues into said molding cavities.
Claim 26
Dependent Claim
142 words
Apparatus for molding glAss comprising: a plurality of mold members having open and closed positions and formed of glasslike carbon, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, said mold members defining a transfer chamber and further defining, when in their closed positions, mold cavities and sprues connecting said transfer chamber and said mold cavities; means for supporting said mold members and for moving said mold members between their open and closed positions; means for heating said mold members above the softening point of glass contained within said transfer chamber; and means for applying pressure to softened glass contained within said transfer chamber to transfer the glass from said transfer chamber through said sprues into said molding cavities.
Claim 27
Dependent Claim
179 words
Apparatus for molding glass comprising: mold members having open and closed positions and formed of glasslike carbon, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, said mold members including surfaces configured to define a transfer chamber and to further define, when said mold members are in said closed positions, mold cavities and sprues connecting said transfer chamber and said mold cavities; means for supporting said mold members and for moving said mold members between their open and closed positions; means defining a molding chamber surrounding said mold members and within which said mold members are movable to their closed positions; means for controlling the atmosphere within said molding chamber; means for heating said mold members above the softening point of a glass contained within said transfer chamber; and means for applying pressure to softened glass contained within said transfer chamber to transfer the glass from said transfer chamber through said sprues into said mold cavities.
Claim 28
Dependent Claim
179 words
Apparatus for molding glass comprising: mold members having open and closed positions and formed of glasslike carbon, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, said mold members including surfaces configured to define a transfer chamber and to further define, when said mold members are in said closed positions, mold cavities and sprues connecting said transfer chamber and said mold cavities; means for supporting said mold members and for moving said mold members between their open and closed positions; means defining a molding chamber surrounding said mold members and within which said mold members are movable to their closed positions; means for controlling the atmosphere within said molding chamber; means for heating said mold members above the softening point of a glass contained within said transfer chamber; and means for applying pressure to softened glass contained within said transfer chamber to transfer the glass from said transfer chamber through said sprues into said mold cavities.
Claim 29
Dependent Claim
103 words
A mold for glass comprising a plurality of mold members formed of glasslike carbon, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, said mold members being relatively movable between open and closed positions, said mold members defining a transfer chamber and further defining, when in said closed positions, a plurality of mold cavities and sprues connecting said transfer chamber and said mold cavities to permit transfer of glass from said transfer chamber through said sprues into said mold cavities.
Claim 30
Dependent Claim
103 words
A mold for glass comprising a plurality of mold members formed of glasslike carbon, the glasslike carbon being a form of carbon which has been prepared by the thermal degradation of an organic polymer, which is substantially chemically inert with heated glass, and which is isotropic, said mold members being relatively movable between open and closed positions, said mold members defining a transfer chamber and further defining, when in said closed positions, a plurality of mold cavities and sprues connecting said transfer chamber and said mold cavities to permit transfer of glass from said transfer chamber through said sprues into said mold cavities.
Claim 31
Dependent Claim
37 words
A mold according to claim 15 where said mold members define a sprue between said transfer chamber and each of said plurality of mold cavities, whereby each mold cavity may simultaneously receive glass from said transfer chamber.
Claim 32
Dependent Claim
62 words
A mold according to claim 15 where said mold members define a sprue between said transfer chamber and a first one of said plurality of mold cavities, and said mold members further define a sprue between each of said mold cavities and at least one other of said mold cavities, whereby said mold cavities may sequentially receive glass from said transfer chamber.
References Cited (Backward Citations)
US3725023A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |