US3856499A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shaping heat-softened glass sheets by roll forming
Assignee: PPG Industries Inc
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Filing: 1973-06-20
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Granted: 1974-12-24
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Expires: 1993-06-20
Abstract
Abstract A method of shaping a deformable sheet by roll forming which includes the steps of applying a bending force with a pair of opposed sets of complementary shaping rolls to initially shape the sheet into proximate conformity with the shaping surfaces of said rolls, discontinuing the application of said bending force before the rolls are in complete surface-to-surface contact with the sheet and permitting the sheet to sag bend into further conformity with the lower of said opposed sets of shaping rolls.
Inventors
- 👤 R Frank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:49
CPC Classifications
C; C03; C03B; C03B23/00; C03B23/02; C03B23/023; C03B23/03; C03B23/033
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
262 words
A method of shaping deformable sheets by a roll forming method comprising moving a flat sheet while said sheet is at its deformation temperature between a pair of opposed sets of rotatable shaping rolls having complementary shaping surfaces and disposed one set above the other set when the sets are separated sufficiently to provide clearance for the entry of said flat sheet between said sets, and when said flat sheet is moving between said sets, providing relative movement between said sets toward one another until one of said sets of shaping rolls rotatably engages a portion of one surface of said sheet intermediate its opposite edges and the other of said sets of shaping rolls rotatably engage a portion of the other surface of said sheet along its opposite edge portions, whereby said relatively moving sets apply a bending force tending to shape said sheet into conformity with said complementary shaping surfaces, discontinuing said relative movement of said sets toward one another to discontinue the application of said bending force when said sets reach a position where they are separated by a predetermined distance slightly more than the thickness of said glass sheet, continuing to move said sheet between said sets, disengaging said sheet from the set disposed above the other set to support said sheet on said other set in rolling engagement therewith, providing relative movement between said sets to separate said sets, and removing said shaped sheet from between said sets before it cools below an elevated temperature sufficient to impart at least a partial temper by subsequent rapid cooling.
Claim 2
Independent Claim
262 words
A method of shaping deformable sheets by a roll forming method comprising moving a flat sheet while said sheet is at its deformation temperature between a pair of opposed sets of rotatable shaping rolls having complementary shaping surfaces and disposed one set above the other set when the sets are separated sufficiently to provide clearance for the entry of said flat sheet between said sets, and when said flat sheet is moving between said sets, providing relative movement between said sets toward one another until one of said sets of shaping rolls rotatably engages a portion of one surface of said sheet intermediate its opposite edges and the other of said sets of shaping rolls rotatably engage a portion of the other surface of said sheet along its opposite edge portions, whereby said relatively moving sets apply a bending force tending to shape said sheet into conformity with said complementary shaping surfaces, discontinuing said relative movement of said sets toward one another to discontinue the application of said bending force when said sets reach a position where they are separated by a predetermined distance slightly more than the thickness of said glass sheet, continuing to move said sheet between said sets, disengaging said sheet from the set disposed above the other set to support said sheet on said other set in rolling engagement therewith, providing relative movement between said sets to separate said sets, and removing said shaped sheet from between said sets before it cools below an elevated temperature sufficient to impart at least a partial temper by subsequent rapid cooling.
Claim 3
Dependent Claim
236 words
A method as in claim 1, wherein said deformable sheets are a series of flat glass sheets, further including the step of heating said series of flat glass sheets to the glass deformation temperature prior to moving the leading sheet of said series into position between said pair of opposed sets of rotatable shaping rolls, providing relative movement between said sets toward one another while said leading sheets is moving between said sets to provide simultaneous rotatable engagements of said sets against each of the opposite glass sheet surfaces along several lines of rotatable engagement extending transverse to the direction of glass sheet movement and that are misaligned from surface to surface, discontinuing said rotatable engagement of at least one of said sets against said surface rotatably engaged by said set before said lines of engagement extend transversely to where a sufficient portion of said lines of engagement against one of the glass sheet surfaces becomes aligned through the glass thickness with a portion of said lines of engagement against the other glass sheet surface to cause surface marking in the region of said alignment, removing said sheet from between said sets of shaping rolls before said glass sheets cool to below the strain point of the glass, and providing relative movement between said sets to a retracted position to provide clearance for entry of the next successive glass sheet in said series between said sets.
Claim 4
Dependent Claim
162 words
A method as in claim 2, wherein said one set of shaping rolls disposed above the other set comprises shaping rolls having convex curvatures and said other set of shaping rolls comprises shaping rolls having concave curvatures, further including initially lifting said leading glass sheet along its opposite edge portions by said other set of shaping rolls while the latter rotate to provide rolling engagement to convey said glass sheet between said sets of shaping rolls, rotating said one set of shaping rolls to rotatably engage the upper surface of said glass sheet intermediate its opposite edges, said offset rolling engagements applying bending force to said sheet, and sagging said sheet away from said one set of shaping rolls into rotatable engagement by said other set of shaping rolls in the portions intermediate said opposite edge portions lifted by said other set before both of said sets apply rolling engagement against both surfaces of said glass sheet from edge to edge thereof.
Claim 5
Dependent Claim
33 words
The method as in claim 3, wherein said glass sheets are supported in spaced relation between said sets of shaping rolls when they are moved into position between said sets of shaping rolls.
Claim 6
Dependent Claim
24 words
A method as in claim 1, wherein said sheet is supported in an oblique plane while moved between said sets of rotating shaping rolls.
References Cited (Backward Citations)
US3701644A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |