US3894137A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of doming planar sheets
Assignee: Roehm GmbH Darmstadt
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Filing: 1972-10-17
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Granted: 1975-07-08
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Expires: 1992-10-17
Abstract
Abstract A method for cold-forming a sheet of stretched or unstretched thermoplastic synthetic resin to form a domed body by tightly clamping said sheet in edge portions, heating only the clamped portions above the freezing point of the resin, cooling the heated clamped portions slightly below the freezing point of the resin, releasing the clamping, and further cooling the edges to room temperature. Single-wall and double-wall domes useful as structural elements, e.g. skylights, can be formed by this method.
Inventors
- 👤 Theodor Peter Moench
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:06
CPC Classifications
B; B29; B29C; B29C67/00; B29B; B29B13/00; B29B13/02; B29B13/023; B29C51/00; B29C51/006; B29C67/0011; Y; Y10; Y10S; Y10S264/00; Y10S264/71; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1043; Y10T156/1044; Y10T156/1048
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
82 words
A cold-forming method for doming a planar sheet of a thermoplastic synthetic resin which comprises tightly clamping said sheet along edge portions thereof, heating only the clamped edge portions of the sheet to a temperature above the glass transition temperature of the resin, cooling the heated clamped edge portions slightly below the glass transition temperature of the resin, releasing the clamping, and further cooling the edges to room temperature, whereupon unheated central portions of the planar sheet deform to form a dome.
Claim 2
Dependent Claim
82 words
A cold-forming method for doming a planar sheet of a thermoplastic synthetic resin which comprises tightly clamping said sheet along edge portions thereof, heating only the clamped edge portions of the sheet to a temperature above the glass transition temperature of the resin, cooling the heated clamped edge portions slightly below the glass transition temperature of the resin, releasing the clamping, and further cooling the edges to room temperature, whereupon unheated central portions of the planar sheet deform to form a dome.
Claim 3
Dependent Claim
36 words
A method as in claim 1 wherein said sheet of thermoplastic synthetic resin is mono-axially or bi-axially stretched prior to cold-forming according to the invention, and is clamped in all edge portions thereof during said cold-forming.
Claim 4
Dependent Claim
20 words
A method as in claim 1 wherein said planar sheet is circular and is clamped and heated along its circumference.
Claim 5
Dependent Claim
22 words
A method as in claim 1 wherein said planar sheet is a polygon and is clamped and heated along all its edges.
Claim 6
Dependent Claim
12 words
A method as in claim 4 wherein said polygon is a rectangle.
Claim 7
Dependent Claim
12 words
A method as in claim 4 wherein said polygon is a square.
Claim 8
Dependent Claim
37 words
A method as in claim 1 wherein said planar sheet is a polygon having at least two opposing edges parallel to a line of symmetry and is clamped and heated along at least said two opposing edges.
Claim 9
Dependent Claim
119 words
A COLD-FORMING METHOD FOR MAKING A DOUBLE-WALLED DOMED, STRUCRURAL ELEMENT WHICH COMPRISES TIGHTLY CLAMPING TWO SUPERIMPOSED THERMOPLASTIC SYNTHETIC RESIN SHEETS ALONG ALL EDGE PORTIONS THEREOF, HEATING ONLY THE CLAMPED EDGE PORTIONS OF THE SHEETS TO A TEMPERATURE ABOVE THE GLASS TRANSITION TEMPERATURE OF THE RESIN TO WELD THE SHEETS TOGETHER IN SAID EDGE PORTIONS, COOLING THE HEATED CLAMPED EDGE PORTIONS SLIGHTLY BELOW THE GLASS TRANSITION TEMPERATURE OF THE RESIN RELEASING THE CLAMPING, AND FURTHER COOLING THE WELDED EDGES TO ROOM TEMPERATURE, WHEREUPON UNHEATED CONTRAL PORTIONS OF SAID PLANAR SHEETS EDROM TO FORM A DOUBLE-WALLED DOME, AT LEAST ONE OF SAID SHEETS HAVING AN APERTURE THEREIN WHEREBY THE PRESSURE BETWEEN THE WALLS OF SAID DOME AND AMBIENT PRESSURE ARE EQUALIZED.
Claim 10
Dependent Claim
119 words
A COLD-FORMING METHOD FOR MAKING A DOUBLE-WALLED DOMED, STRUCRURAL ELEMENT WHICH COMPRISES TIGHTLY CLAMPING TWO SUPERIMPOSED THERMOPLASTIC SYNTHETIC RESIN SHEETS ALONG ALL EDGE PORTIONS THEREOF, HEATING ONLY THE CLAMPED EDGE PORTIONS OF THE SHEETS TO A TEMPERATURE ABOVE THE GLASS TRANSITION TEMPERATURE OF THE RESIN TO WELD THE SHEETS TOGETHER IN SAID EDGE PORTIONS, COOLING THE HEATED CLAMPED EDGE PORTIONS SLIGHTLY BELOW THE GLASS TRANSITION TEMPERATURE OF THE RESIN RELEASING THE CLAMPING, AND FURTHER COOLING THE WELDED EDGES TO ROOM TEMPERATURE, WHEREUPON UNHEATED CONTRAL PORTIONS OF SAID PLANAR SHEETS EDROM TO FORM A DOUBLE-WALLED DOME, AT LEAST ONE OF SAID SHEETS HAVING AN APERTURE THEREIN WHEREBY THE PRESSURE BETWEEN THE WALLS OF SAID DOME AND AMBIENT PRESSURE ARE EQUALIZED.
Claim 11
Dependent Claim
14 words
A method as in claim 2 wherein said superimposed synthetic resin sheets are circular.
Claim 12
Dependent Claim
14 words
A method as in claim 2 wherein said superimposed synthetic resin sheets are square.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |