US3961927A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for moulding glass objects
Assignee: Pilkington Group Ltd
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Filing: 1975-07-02
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Granted: 1976-06-08
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Expires: 1995-07-02
Abstract
Abstract A method of shaping glass to a desired form comprises delivering molten glass on to a porous support member while feeding a gas under pressure through the porous support member from the reverse side thereof, so as to support the molten glass out of contact with the support member on a cushion of gas, allowing the glass to assume a shape approximating to that of the support member under the forces of surface tension, gravity and gas cushion pressure, cooling the glass while thus supported on the gas cushion to a temperature at which it is so conditioned that it can be shaped by contact with a solid surface without any substantial surface damage, and shaping the conditioned glass by a shaping process which involves contact with a solid surface. The shaping process may be a moulding process, which can be carried out either in the porous support member or in a separate mould to which the glass is transferred. The gas, e.g. nitrogen or nitrogen + 5% hydrogen, may be fed to the porous support member at ambient temperature. Alternatively, for controlling the rate of heat transfer from the supported glass, the temperature and/or flow rate of the gas may be controlled, or the temperature of the environment of the porous support member may be controlled, e.g. using a muffle. The shaping process may alternatively be a rolling process, the glass flowing from a channel-shaped porous support member to a pair of rollers.
Inventors
- 👤 John Victor Alderson
- 👤 Donald Frederick Stanley
- 👤 John Duncan Rudd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:43
CPC Classifications
C; C03; C03B; C03B40/00; C03B40/04; C03B13/00; C03B13/04; C03B17/00; C03B17/06; C03B17/061; C03B17/062; C03B19/00; C03B19/02; C03B35/00; C03B35/14; C03B35/22; C03B35/24; C03B35/246; C03B7/00; C03B7/14; Y; Y02; Y02P; Y02P40/00; Y02P40/50; Y02P40/57
Claims Analysis
Total Claims: 52
Claim 1
Independent Claim
276 words
A method of shaping glass to a desired form in which delivered molten glass can be brought to a suitable viscosity condition for shaping independently of the viscosity of delivery, the method comprising: feeding gas under pressure through minute, tortuous, gas flow channels of a porous wall of a support member, located at least at the base of the support member, from the reverse side of said wall into a support cavity defined by a cavity surface presented by the support member; delivering molten glass into the support cavity, while so feeding the gas under a pressure sufficient to support the glass, while it is in a viscosity condition wherein it can distort or flow, out of contact with the cavity surface on a cushion of gas, but insufficient to induce perceptible gas stream or blast to blow from the cavity surface so as to push the glass actively away from the cavity surface; maintaining the glass floating freely in the support cavity on the established gas cushion support of the glass, out of contact with the cavity surface, for a hold time during which the glass in the support cavity is allowed to assume, under the forces of surface tension, gravity and gas cushion pressure, a shape approximating to that of the support cavity and having a fire-finished glass surface, and the glass is cooled to a viscosity condition such that it can be further shaped by contact with a solid surface without any substantial surface damage to the fire-finished glass surface formed on the gas cushion; and shaping the so conditioned glass by a shaping process which involves contact with such a solid surface.
Claim 2
Independent Claim
276 words
A method of shaping glass to a desired form in which delivered molten glass can be brought to a suitable viscosity condition for shaping independently of the viscosity of delivery, the method comprising: feeding gas under pressure through minute, tortuous, gas flow channels of a porous wall of a support member, located at least at the base of the support member, from the reverse side of said wall into a support cavity defined by a cavity surface presented by the support member; delivering molten glass into the support cavity, while so feeding the gas under a pressure sufficient to support the glass, while it is in a viscosity condition wherein it can distort or flow, out of contact with the cavity surface on a cushion of gas, but insufficient to induce perceptible gas stream or blast to blow from the cavity surface so as to push the glass actively away from the cavity surface; maintaining the glass floating freely in the support cavity on the established gas cushion support of the glass, out of contact with the cavity surface, for a hold time during which the glass in the support cavity is allowed to assume, under the forces of surface tension, gravity and gas cushion pressure, a shape approximating to that of the support cavity and having a fire-finished glass surface, and the glass is cooled to a viscosity condition such that it can be further shaped by contact with a solid surface without any substantial surface damage to the fire-finished glass surface formed on the gas cushion; and shaping the so conditioned glass by a shaping process which involves contact with such a solid surface.
Claim 3
Dependent Claim
16 words
A method according to claim 1, wherein the conditioned glass is shaped by a moulding process.
Claim 4
Dependent Claim
19 words
A method according to claim 2, wherein a measured quantity of molten glass is delivered into the support cavity.
Claim 5
Dependent Claim
14 words
A method according to claim 1, wherein the gas is fed at ambient temperature.
Claim 6
Dependent Claim
37 words
A method according to claim 1, wherein the rate of heat transfer from the glass, while supported on the gas cushion, is controlled by controlling the temperature of the gas and/or the flow rate of the gas.
Claim 7
Dependent Claim
33 words
A method according claim 1, wherein the rate of heat transfer from the glass, while supported on the gas cushion, is controlled by controlling the temperature of the environment of the support member.
Claim 8
Dependent Claim
30 words
A method according to claim 1, wherein the gas is fed to the mould at a pressure of the order of 1 to 30 pounds per square inch above atmospheric.
Claim 9
Dependent Claim
11 words
A method according to claim 1, wherein the gas is nitrogen.
Claim 10
Dependent Claim
20 words
A method according to claim 1, wherein the gas is a mixture of nitrogen with substantially 5% by volume hydrogen.
Claim 11
Dependent Claim
28 words
A method according to claim 2, wherein the conditioned glass is removed from the support cavity to a separate mould in which the moulding process is carried out.
Claim 12
Dependent Claim
55 words
A method according to claim 10, wherein a plurality of the support cavities are indexed around a closed path between a delivery station at which the glass is delivered into each support cavity in turn and a transfer station at which the glass is removed from the support cavity for delivery to a moulding station.
Claim 13
Dependent Claim
49 words
A method according to claim 11, wherein the glass in each support cavity in turn is gripped by a suction-operated gripping means when the support cavity arrives at the transfer station, and the glass is then lifted out of the support cavity, inverted and delivered to the moulding station.
Claim 14
Dependent Claim
27 words
A method according to claim 12, wherein the suction-operated gripping means is swung about a substantially horizontal axis to effect the lifting and inversion of the glass.
Claim 15
Dependent Claim
26 words
A method according to claim 13, wherein the inverted glass is released by the gripping means and passes down an inclined chute to the moulding station.
Claim 16
Dependent Claim
41 words
A method according to claim 12, wherein the suction-operated gripping means is lifted and then swung about a substantially vertical axis, while being simultaneously inverted by being turned about a horizontal axis, to effect the lifting and inversion of the glass.
Claim 17
Dependent Claim
29 words
A method according to claim 15, wherein the mould is lowered on to the inverted gripping means at the moulding station to mould the glass to the desired form.
Claim 18
Dependent Claim
36 words
A method according to claim 16 wherein, after moulding, the moulded glass is lifted by the mould and then released on to a laterally swinging chute, down which the moulded glass passes to an annealing lehr.
Claim 19
Dependent Claim
28 words
A method according to claim 2, wherein the moulding process is carried out by pressing the glass into contact with the support member, which constitutes a mould member.
Claim 20
Dependent Claim
37 words
A method according to claim 18, using an open-topped support member with walls of concave shape, wherein a pressing tool is pressed down on to the glass from above to form the glass to the desired shape.
Claim 21
Dependent Claim
21 words
A method according to claim 18, wherein the feeding of the gas under pressure is discontinued before the glass is pressed.
Claim 22
Dependent Claim
21 words
A method according to claim 19, wherein the feeding of the gas under pressure is continued while the glass is pressed.
Claim 23
Dependent Claim
16 words
A method according to claim 1 wherein the conditioned glass is shaped by a rolling process.
Claim 24
Dependent Claim
28 words
A method according to claim 22, wherein the conditioned Glass is fed directly from the support member to at least one pair of internally cooled, polished finishing rollers.
Claim 25
Dependent Claim
75 words
A method according to claim 22, of shaping glass to ribbon form, using a channel-shaped support member, wherein the glass, while supported on the gas cushion, is allowed to flow along the channel-shaped support member while assuming a ribbon shape under the forces of surface tension, gravity and gas cushion pressure, and the conditioned glass is then passed between at least one pair of polished rollers to shape it to the desired final ribbon form.
Claim 26
Dependent Claim
290 words
Apparatus for shaping glass to a desired form in which delivered molten glass can be brought to a suitable viscosity condition for shaping independently of the viscosity of delivery, the apparatus comprising: a support member having a porous wall located at least at the base thereof and presenting minute, tortuous, gas flow channels, said support member presenting a cavity surface defining a support cavity; means for delivering molten glass into said support cavity; means for feeding gas through said porous wall of said support member, from the reverse side thereof into said support cavity at a pressure sufficient to support the glass, while it is in a viscosity condition wherein it can distort or flow, out of contact with the cavity surface on a cushion of gas, but insufficient to induce a perceptible gas stream or blast to blow from the cavity surface so as to push the glass actively away from that cavity surface; said gas feeding means and said support cavity being cooperable to maintain the glass floating freely in the support cavity on the established gas cushion support of the glass, out of contact with the cavity surface, for a hold time during which the glass in the support cavity is allowed to assume, under the forces of surface tension, gravity and gas cushion pressure, a shape approximating to that of the support cavity and having a fire-finished glass surface; and the glass is cooled to a viscosity condition such that it can be further shaped by contact with a solid surface without any substantial surface damage to the fire-finished glass surface formed on the gas cushion; and means for subsequently shaping the so conditioned glass by a shaping process which involves contact with a solid surface.
Claim 27
Dependent Claim
290 words
Apparatus for shaping glass to a desired form in which delivered molten glass can be brought to a suitable viscosity condition for shaping independently of the viscosity of delivery, the apparatus comprising: a support member having a porous wall located at least at the base thereof and presenting minute, tortuous, gas flow channels, said support member presenting a cavity surface defining a support cavity; means for delivering molten glass into said support cavity; means for feeding gas through said porous wall of said support member, from the reverse side thereof into said support cavity at a pressure sufficient to support the glass, while it is in a viscosity condition wherein it can distort or flow, out of contact with the cavity surface on a cushion of gas, but insufficient to induce a perceptible gas stream or blast to blow from the cavity surface so as to push the glass actively away from that cavity surface; said gas feeding means and said support cavity being cooperable to maintain the glass floating freely in the support cavity on the established gas cushion support of the glass, out of contact with the cavity surface, for a hold time during which the glass in the support cavity is allowed to assume, under the forces of surface tension, gravity and gas cushion pressure, a shape approximating to that of the support cavity and having a fire-finished glass surface; and the glass is cooled to a viscosity condition such that it can be further shaped by contact with a solid surface without any substantial surface damage to the fire-finished glass surface formed on the gas cushion; and means for subsequently shaping the so conditioned glass by a shaping process which involves contact with a solid surface.
Claim 28
Dependent Claim
26 words
Apparatus according to claim 25, wherein the means for shaping the glass by a process which involves contact with a solid surface is a moulding device.
Claim 29
Dependent Claim
27 words
Apparatus according to claim 26, wherein the means for delivering molten glass is adapted to deliver a measured quantity of the molten glass into the support cavity.
Claim 30
Dependent Claim
23 words
Apparatus according to claim 25, wherein means are provided for controlling the temperature of the gas and/or the flow rate of the gas.
Claim 31
Dependent Claim
20 words
Apparatus according to claim 25, wherein means are provided for controlling the temperature of the environment of the support member.
Claim 32
Dependent Claim
47 words
Apparatus according to claim 26, wherein the support member is movable between a delivery station where the means for delivering molten glass are situated, and a transfer station provided with means for removing the glass from the support cavity and for transferring it to the moulding device.
Claim 33
Dependent Claim
47 words
Apparatus according to claim 30, wherein the means for controlling the temperature of the environment of the support member comprise a tunnel-shaped enclosure surrounding the path of the support member between the delivery station and the transfer station, and means for controlling the temperature in the enclosure.
Claim 34
Dependent Claim
21 words
Apparatus according to claim 31, wherein the means for controlling the temperature in the enclosure comprise heating means in the enclosure.
Claim 35
Dependent Claim
50 words
Apparatus according to claim 30, wherein a plurality of the support cavities are mounted on a rotary table or turret and means are provided for imparting a rotary indexing movement to the table or turret to move the support cavities in turn from the delivery station to the transfer station.
Claim 36
Dependent Claim
56 words
An apparatus according to claim 30, wherein the means for removing and transferring the glass include suction-operated gripping means arranged to grip the glass by suction when the support cavity reaches the transfer station and then to lift the glass out of the support cavity and invert it, before it is delivered to the moulding device.
Claim 37
Dependent Claim
32 words
Apparatus according to claim 34, wherein the suction operated gripping means is mounted for swinging movement about a substantially horizontal axis so as to effect the lifting and inversion of the glass.
Claim 38
Dependent Claim
34 words
Apparatus according to claim 34, wherein an inclined chute is provided to receive the glass from the suction-operated gripping means after inversion of the glass and to transfer the glass to the moulding device.
Claim 39
Dependent Claim
89 words
Apparatus according to claim 34, wherein the means for removing and transferring the glass comprise a substantially horizontal arm carrying the suction-operated gripping means at one end, means for lifting the arm to remove the glass from the support member, means for swinging the arm about a substantially vertical axis and means for rotating the arm about its own axis while it is being swung about the substantially vertical axis, so as to invert the gripping means and the glass and to transfer the glass to the moulding device.
Claim 40
Dependent Claim
39 words
Apparatus according to claim 37, wherein the mouding device comprises a mould, and means for lowering the mould on to the inverted gripping means, to mould the glass to the desired form, and for subsequently raising the mould therefrom.
Claim 41
Dependent Claim
59 words
Apparatus according to claim 38, wherein the means are providing for ejecting the moulded glass article from the mould after the mould has been raised, and a laterally swingable inclined chute is arranged to swing into position below the mould after it has been raised to receive the moulded glass article and to transfer it to an annealing lehr.
Claim 42
Dependent Claim
28 words
Apparatus according to claim 38, wherein the moulding device comprises means for pressing the glass into contact with the support member, which member thus constitutes a mould member.
Claim 43
Dependent Claim
51 words
Apparatus according to claim 40, comprising a plurality of open-topped support members with porous side and bottom walls of concave shape, and means for indexing the support members between stations provided respectively with the glass delivery means, the pressing means, and means for emptying the pressed glass from the support cavities.
Claim 44
Dependent Claim
26 words
Apparatus according to claim 25, wherein the means for shaping the glass by a process which involves contact with a solid surface is a rolling device.
Claim 45
Dependent Claim
20 words
Apparatus according to claim 42, wherein the rolling device comprises at least one pair of internally cooled, polished finishing rollers.
Claim 46
Dependent Claim
54 words
Apparatus according to claim 42, for shaping glass to ribbon form, wherein the support member is channel-shaped to permit the glass to flow along it while assuming a ribbon shape, and the rolling device comprises at least one pair of polished rollers arranged to receive the glass as it flows from the support member.
Claim 47
Dependent Claim
15 words
Apparatus according to claim 25, wherein the support member is formed from sintered stainless steel.
Claim 48
Dependent Claim
14 words
Apparatus according to claim 25, wherein the support member is formed from sintered nickel.
Claim 49
Dependent Claim
15 words
Apparatus according to claim 25, wherein the support member is formed from sintered Monel metal.
Claim 50
Dependent Claim
35 words
Apparatus according to claim 45, wherein the internal surface of the support member has been finished by mechanical polishing, followed by electrolytic etching to open pores sealed by the mechanical polishing, followed by hand polishing.
Claim 51
Dependent Claim
14 words
Apparatus according to claim 25, wherein the support member is formed from porous graphite.
Claim 52
Dependent Claim
16 words
Apparatus according to claim 25, wherein the support member is formed from a porous ceramic material.
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) | 1979-06-08 | 1979-12-08 | 1980-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-08 | 1983-12-08 | 1984-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-08 | 1987-12-08 | 1988-06-08 | $7700.00 | Window Closed / Lapsed |