Patent US3790326A successfully refreshed from Google Patents.
US3790326A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extrusion apparatus
Assignee: Leucadia Inc
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Filing: 1971-11-26
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Granted: 1974-02-05
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Expires: 1991-11-26
Abstract
Abstract An apparatus is provided for the extrusion of polymer products from a pool of molten polymer. The apparatus is comprised of at least two movable die members between which the polymer is extruded. The moveable die members apply pressure to the surface of the extruding sheet to spread and smooth out gauge variations in the extruded product to reduce the visual effects of the gauge variations on the extruded sheet.
Inventors
- 👤 R Larsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:34
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/30; B29C48/35; B29C48/03; B29C48/07; B29C48/08; B29C48/13; B29C48/305; B29C48/315; B29C48/001; B29C48/0022
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
163 words
An apparatus for controlling gauge variations on a sheet of polymer comprising: a. two die members approximately uniformly spaced apart over a substantial length thereof for forming melt extrusion of a desired gauge sheet of molten polymer; b. two spaced heated, continuously moving members disposed immediately adjacent the uniformly spaced length of the die members, each of which is immediately adjacent one of said uniformly spaced die members; c. the space between the continuously moving members being essentially equal to the uniform space between the die members; d. the continuously moving members being disposed to contact and act on the sheet surface of the sheet of polymer while it is still molten from extrusion and before it has set to reduce the variations in the sheet planar surface to maintain uniform sheet thickness only within the moving members limit; and e. the temperature of the contacting surface of said continuously moving members being approximately equal to the temperature of the molten polymer sheet.
Claim 2
Independent Claim
163 words
An apparatus for controlling gauge variations on a sheet of polymer comprising: a. two die members approximately uniformly spaced apart over a substantial length thereof for forming melt extrusion of a desired gauge sheet of molten polymer; b. two spaced heated, continuously moving members disposed immediately adjacent the uniformly spaced length of the die members, each of which is immediately adjacent one of said uniformly spaced die members; c. the space between the continuously moving members being essentially equal to the uniform space between the die members; d. the continuously moving members being disposed to contact and act on the sheet surface of the sheet of polymer while it is still molten from extrusion and before it has set to reduce the variations in the sheet planar surface to maintain uniform sheet thickness only within the moving members limit; and e. the temperature of the contacting surface of said continuously moving members being approximately equal to the temperature of the molten polymer sheet.
Claim 3
Dependent Claim
16 words
The apparatus of claim 1 wherein the continuously moving members move in the direction of extrusion.
Claim 4
Dependent Claim
12 words
The apparatus of claim 2 wherein the continuously moving members are rolls.
Claim 5
Dependent Claim
12 words
The apparatus oF claim 2 wherein the continuously moving members are belts.
Claim 6
Dependent Claim
25 words
The apparatus of claim 2 wherein the continuously moving member is moved at the same rate as the speed of extrusion of the polymer sheet.
Claim 7
Dependent Claim
20 words
The apparatus of claim 1 wherein the continuously moving members move in a direction transverse to the direction of extrusion.
Claim 8
Dependent Claim
12 words
The apparatus of claim 6 wherein the continuously moving members are belts.
Claim 9
Dependent Claim
12 words
The apparatus of claim 6 wherein the continuously moving members are bars.
References Cited (Backward Citations)
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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) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |