US3778244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bending of flat glass on a mold with vacuum
Assignee: Saint Gobain Industries SA
•
Filing: 1971-04-22
•
Granted: 1973-12-11
•
Expires: 1991-04-22
Abstract
Abstract The invention involves a method of bending a sheet of thermoplastic material which comprises heating the sheet to bending temperature, placing it adjacent a shaping form, pneumatically forcing the sheet toward and bending it against the form, and cooling the bent sheet; and apparatus for the bending of thermoplastic sheets which comprises a bending form, means to transport a hot thermoplastic sheet into proximity to the bending form, pneumatic means to bend the sheet against the form, and means to cool the bent sheet.
Inventors
- 👤 M Nedelec
- 👤 J Pettitcollin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:01
CPC Classifications
C; C03; C03B; C03B23/00; C03B23/02; C03B23/023; C03B23/035; C03B23/0352; C03B23/0357; C03B23/03
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
82 words
A method of bending a sheet of thermoplastic material which comprises heating the sheet to bending temperature, placing it in alignment with a shaping form, and lifting the sheet against the form by aspiration applied through a restricted passage around the periphery of the form and between the form and the skirt of an evacuated hood closely surrounding said periphery, the rate of aspiration being such that the sheet is lifted and bent into contact with the shaping surface of the form.
Claim 2
Independent Claim
82 words
A method of bending a sheet of thermoplastic material which comprises heating the sheet to bending temperature, placing it in alignment with a shaping form, and lifting the sheet against the form by aspiration applied through a restricted passage around the periphery of the form and between the form and the skirt of an evacuated hood closely surrounding said periphery, the rate of aspiration being such that the sheet is lifted and bent into contact with the shaping surface of the form.
Claim 3
Dependent Claim
16 words
The method of claim 1 which includes simultaneously applying aspiration through perforations in the bending form.
Claim 4
Independent Claim
72 words
The method of bending a sheet of thermoplastic material which includes the steps of heating the sheet to bending temperature, placing it in alignment with a shaping form, lifting the sheet against the form by aspiration applied to the periphery of the sheet, and pneumatically bending the sheet against the said shaping form and perfecting the contours of the sheet by pressing the sheet mechanically between said form and a complementary form.
Claim 5
Independent Claim
72 words
The method of bending a sheet of thermoplastic material which includes the steps of heating the sheet to bending temperature, placing it in alignment with a shaping form, lifting the sheet against the form by aspiration applied to the periphery of the sheet, and pneumatically bending the sheet against the said shaping form and perfecting the contours of the sheet by pressing the sheet mechanically between said form and a complementary form.
Claim 6
Dependent Claim
25 words
The method of claim 3 in which the complementary form yields when a certain pressure is applied by the said shaping form to the sheet.
Claim 7
Independent Claim
121 words
A method of bending a sheet of flat glass which comprises heating it to bending temperature, placing it adjacent the shaping face of a bending form while it is at bending temperature and adjacent the open end of a hood containing said form, applying vacuum to the space within the hood between the shaping face of the form and the sheet through a passage between the circumference of the form and the adjacent inner surface of the hood and thereby reducing the pressure in said space, the application of the vacuum being at a rate such that the sheet is pneumatically lifted and bent against the shaping surface of the form, removing the bent sheet from the form, and cooling it.
Claim 8
Independent Claim
121 words
A method of bending a sheet of flat glass which comprises heating it to bending temperature, placing it adjacent the shaping face of a bending form while it is at bending temperature and adjacent the open end of a hood containing said form, applying vacuum to the space within the hood between the shaping face of the form and the sheet through a passage between the circumference of the form and the adjacent inner surface of the hood and thereby reducing the pressure in said space, the application of the vacuum being at a rate such that the sheet is pneumatically lifted and bent against the shaping surface of the form, removing the bent sheet from the form, and cooling it.
Claim 9
Dependent Claim
26 words
A method of bending a sheet of glass according to claim 5 which comprises simultaneously applying vacuum to said space through passages in the bending form.
Claim 10
Dependent Claim
29 words
A method of bending a sheet of glass according to claim 5 which comprises the step of mechanically bending a part of the vacuum-bent sheet between conforming pressing surfaces.
Claim 11
Dependent Claim
114 words
Apparatus for the bending of hot thermoplastic sheets which comprises a horizontally disposed bending form having a peripheral shape approximating the peripheral shape of the sheet to be bent, hood means encompassing the bending form and having an open end approximating the peripheral shape of the sheet to be bent, there being a clearance space between the periphery of the form and the adjacent inner wall of the hood means, means to move a hot sheet into proximity to and alignment with the bending form and said open end of the hood means, and means to evacuate the space in the hood means between the bending form and the sheet through said clearance space.
Claim 12
Dependent Claim
114 words
Apparatus for the bending of hot thermoplastic sheets which comprises a horizontally disposed bending form having a peripheral shape approximating the peripheral shape of the sheet to be bent, hood means encompassing the bending form and having an open end approximating the peripheral shape of the sheet to be bent, there being a clearance space between the periphery of the form and the adjacent inner wall of the hood means, means to move a hot sheet into proximity to and alignment with the bending form and said open end of the hood means, and means to evacuate the space in the hood means between the bending form and the sheet through said clearance space.
Claim 13
Dependent Claim
16 words
Apparatus according to claim 8 including means to move the hood means and bending form vertically.
Claim 14
Dependent Claim
16 words
Apparatus according to claim 8 including supplemental means to evacuate said space through the bending form.
Claim 15
Dependent Claim
37 words
Apparatus according to claim 8 including means to move bending means of conforming shape into alignment with the bending form, and means to move the bending form and bending means relatively whereby to press the shEet therebetween.
Claim 16
Dependent Claim
14 words
Apparatus according to claim 11 in which the bending means is mounted on balances.
Claim 17
Dependent Claim
36 words
Apparatus according to claim 8 in which the circumference of the unbent sheet is slightly greater than the circumference of the bending form and less than the circumference of the open end of the hood means.
Claim 18
Independent Claim
56 words
A method of bending flat glass which comprises pneumatically lifting a piece of flat glass at bending temperature against a shaping form at bending temperature and pneumatically bending it against the form, releasing the bent glass from the form upon a second form having a complementary shape, and completing the bending pneumatically upon the second form.
Claim 19
Independent Claim
56 words
A method of bending flat glass which comprises pneumatically lifting a piece of flat glass at bending temperature against a shaping form at bending temperature and pneumatically bending it against the form, releasing the bent glass from the form upon a second form having a complementary shape, and completing the bending pneumatically upon the second form.
Claim 20
Dependent Claim
185 words
In apparatus for the bending of flat glass panes which comprises a tunnel having a plurality of interconnected chambers of which a first chamber is provided with means to heat flat glass panes to bending temperature, a second chamber is provided with bending apparatus, and a third chamber comprises cooling means, conveyor means movable between the second and third chambers, vertically movable bending means in the second chamber comprising an aspirated hood having an internal periphery complementary to and slightly longer than the periphery of the flat glass panes being bent and means within the hood to bend the panes having a periphery complementary to said periphery of the hood and spaced therefrom to form a peripheral passage, means to aspirate the hood and to thereby aspirate the space between said last-named means and a pane therebelow through said peripheral passage to lift the pane into the hood against said means to bend the panes when a pane is in alignment therewith, means to raise and lower said bending means, and means to release the vacuum and release the bent pane to the conveyor means.
Claim 21
Dependent Claim
185 words
In apparatus for the bending of flat glass panes which comprises a tunnel having a plurality of interconnected chambers of which a first chamber is provided with means to heat flat glass panes to bending temperature, a second chamber is provided with bending apparatus, and a third chamber comprises cooling means, conveyor means movable between the second and third chambers, vertically movable bending means in the second chamber comprising an aspirated hood having an internal periphery complementary to and slightly longer than the periphery of the flat glass panes being bent and means within the hood to bend the panes having a periphery complementary to said periphery of the hood and spaced therefrom to form a peripheral passage, means to aspirate the hood and to thereby aspirate the space between said last-named means and a pane therebelow through said peripheral passage to lift the pane into the hood against said means to bend the panes when a pane is in alignment therewith, means to raise and lower said bending means, and means to release the vacuum and release the bent pane to the conveyor means.
Claim 22
Dependent Claim
23 words
Apparatus according to claim 15 in which said means to bend has a perforated, curved, bending surface, and aspirator means operatively connected thereto.
Claim 23
Dependent Claim
82 words
Apparatus according to claim 15 in which the conveyor means includes a carriage having a surface which conforms to the shape of the rim of the bent pane and the bending means has a surface adapted to press the pane against the said carriage surface, thereby providing the pane with accurate circumferential shape, and comprising means to move the carriage beneath the hood to receive the bent pane when it is released by the bending means and thence into the cooling chamber.
Claim 24
Dependent Claim
35 words
Apparatus according to claim 17 in which means for receiving the bent pane is mounted on the carriage upon balances which yield when a certain pressure is exerted upon the pane by the bending means.
Claim 25
Dependent Claim
76 words
Apparatus according to claim 15 in which the conveyor means includes a carriage which has a shape corresponding to the bending face of the bending means and to the conformation desired in the bent pane and a perforated surface, and comprising aspirator means operatively connected to the perforations, and means to move the carriage beneath the hood to receive the bent pane when it is released by the bending means and thence into the cooling chamber.
Claim 26
Independent Claim
38 words
A method of bending flat glass panes which comprises aspirating the flat plane against a vertically positioned bending form and partially bending it, depositing the partially bent pane upon a bending form therebeneath, and completing the bending thereon.
Claim 27
Independent Claim
38 words
A method of bending flat glass panes which comprises aspirating the flat plane against a vertically positioned bending form and partially bending it, depositing the partially bent pane upon a bending form therebeneath, and completing the bending thereon.
Claim 28
Dependent Claim
18 words
A method according to claim 20 in which the bending on the lower form is completed by aspiration.
Claim 29
Independent Claim
85 words
A method of bending glass panes which comprises heating the pane to bending temperature, moving the pane into alignment with and beneath a bending form in spaced relation thereto, surrounding the space between the form and pane by a hood containing the form, pneumatically lifting the pane against the form and bending it upon the form by withdrawing the air from said space radially through the circumferential passage between the peripheral edges of the form and pane, and releasing the bent pane from the form.
Claim 30
Independent Claim
85 words
A method of bending glass panes which comprises heating the pane to bending temperature, moving the pane into alignment with and beneath a bending form in spaced relation thereto, surrounding the space between the form and pane by a hood containing the form, pneumatically lifting the pane against the form and bending it upon the form by withdrawing the air from said space radially through the circumferential passage between the peripheral edges of the form and pane, and releasing the bent pane from the form.
Claim 31
Dependent Claim
28 words
A method according to claIm 22 in which the bending form is perforated and air is simultaneously withdrawn from said space through the perforations in the bending form.
Claim 32
Independent Claim
95 words
A method of bending a sheet of flat glass which comprises heating it to bending temperature, placing it adjacent the shaping face of a bending form which is at bending temperature, applying vacuum to the circumference of the form and the sheet and thereby reducing the pressure between the form and the sheet, maintaining the vacuum until the sheet is pneumatically bent against the form, mechanically bending a part of the vacuum-bent sheet between conforming pressing surfaces, weighing the pressure applied between conforming pressing surfaces, removing the bent sheet from the form, and cooling it.
Claim 33
Independent Claim
95 words
A method of bending a sheet of flat glass which comprises heating it to bending temperature, placing it adjacent the shaping face of a bending form which is at bending temperature, applying vacuum to the circumference of the form and the sheet and thereby reducing the pressure between the form and the sheet, maintaining the vacuum until the sheet is pneumatically bent against the form, mechanically bending a part of the vacuum-bent sheet between conforming pressing surfaces, weighing the pressure applied between conforming pressing surfaces, removing the bent sheet from the form, and cooling it.
Claim 34
Dependent Claim
78 words
Apparatus for the bending of hot thermoplastic sheets which comprises a horizontally disposed bending form having a shape approximating the shape of the sheet to be bent, means to move a hot sheet horizontally into proximity to and alignment with the bending form, hood means encompassing the bending form and having an arcuate shape conforming to the bending path of the rim of the sheet, means to evacuate the hood means, and means to cool the bent sheet.
Claim 35
Dependent Claim
78 words
Apparatus for the bending of hot thermoplastic sheets which comprises a horizontally disposed bending form having a shape approximating the shape of the sheet to be bent, means to move a hot sheet horizontally into proximity to and alignment with the bending form, hood means encompassing the bending form and having an arcuate shape conforming to the bending path of the rim of the sheet, means to evacuate the hood means, and means to cool the bent sheet.
Claim 36
Independent Claim
121 words
A method of bending a sheet of thermoplastic material, such as glass, which comprises heating the sheet to bending temperature, confining a shaping form within an enclosure having an open lower end, placing the sheet below the form and enclosure in alignment therewith and in spaced relation thereto, and evacuating the space between the sheet and the adjacent face of the form by applying suction thereto through a narrow peripheral clearance between the entire periphery of the shaping face of the form and the wall of the enclosure adjacent thereto, whereby the sheet is lifted by ambient pressure into engagement with the form within the enclosure and bent by such pressure into general conformity with the shaping face of the form.
Claim 37
Independent Claim
121 words
A method of bending a sheet of thermoplastic material, such as glass, which comprises heating the sheet to bending temperature, confining a shaping form within an enclosure having an open lower end, placing the sheet below the form and enclosure in alignment therewith and in spaced relation thereto, and evacuating the space between the sheet and the adjacent face of the form by applying suction thereto through a narrow peripheral clearance between the entire periphery of the shaping face of the form and the wall of the enclosure adjacent thereto, whereby the sheet is lifted by ambient pressure into engagement with the form within the enclosure and bent by such pressure into general conformity with the shaping face of the form.
Claim 38
Dependent Claim
22 words
The method of claim 26 wherein the peripheral margin of the unbent sheet extends outwardly slightly beyond the periphery of the form.
Claim 39
Dependent Claim
17 words
The method of claim 27 wherein the unbent sheet fits within the open end of the enclosure.
Claim 40
Dependent Claim
22 words
The method of claim 26 which includes simultaneously applying suction to said space through passages terminating in the face of the form.
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) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |