Patent US4728559A successfully refreshed from Google Patents.
US4728559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermoformed plastic containers with transparent windows and method of making same
Assignee: Eastman Kodak Co
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Filing: 1987-07-16
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Granted: 1988-03-01
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Expires: 2007-07-16
Abstract
Abstract A container component is made from microcellular foam material, no more than approximately 30 mils thick, having a core of very small uniformity distributed cells to provide uniform opacity that is locally eliminated by the application of heat and pressure to create window areas at least 60% as thick as the surrounding material.
Inventors
- 👤 Scott B. Hardenbrook
- 👤 Cynthia L. Desmond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:06
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/34; B29C44/56; B29C44/5627; B29C44/5636; B29C59/00; B29C59/02; B29C71/00; B65; B65D; B65D25/00; B65D25/54; B29C51/00; B29C51/10; B29K; B29K2025/00; B29K2105/00; B29K2105/04; B29K2995/00; B29K2995/0018; B29K2995/0025; B29K2995/0026; B29L; B29L2031/00; B29L2031/778; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/1376; Y10T428/24; Y10T428/24479; Y10T428/24496; Y10T428/24504; Y10T428/24595
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
50 words
A container component made from substantially opaque microcellular foamed sheet plastic material, said component including a transparent window formed by heating and compressing the corresponding region of said material to eliminate foam in that region, said window being at least 60% as thick as said material in its foamed condition.
Claim 2
Dependent Claim
50 words
A container component made from substantially opaque microcellular foamed sheet plastic material, said component including a transparent window formed by heating and compressing the corresponding region of said material to eliminate foam in that region, said window being at least 60% as thick as said material in its foamed condition.
Claim 3
Dependent Claim
21 words
The invention according to claim 1 in which said microcellular foamed sheet plastic material is less than approximately 30 mils thick.
Claim 4
Dependent Claim
12 words
The invention defined by claim 1 in which said material is polystyrene.
Claim 5
Dependent Claim
17 words
The invention defined by claim 1 in which said component is thermoformed to a generally box-like configuration.
Claim 6
Independent Claim
109 words
The method of producing a transparent window in a component made from microcellular foamed sheet plastic material by compressing a region of said material corresponding to said window between confronting smooth surfaces of a mold and a die, said method comprising the steps of: (a) heating the material to a surface temperature in the range of approximately 275°-300° F. (b) maintaining the die at a temperature in the range of approximately 85°-250° F.; (c) maintaining the mold at a temperature in the range of approximately 150°-180° F.; and (d) urging said die toward said mold with a pressure of at least 2000 pounds per square inch of window area.
Claim 7
Independent Claim
109 words
The method of producing a transparent window in a component made from microcellular foamed sheet plastic material by compressing a region of said material corresponding to said window between confronting smooth surfaces of a mold and a die, said method comprising the steps of: (a) heating the material to a surface temperature in the range of approximately 275°-300° F. (b) maintaining the die at a temperature in the range of approximately 85°-250° F.; (c) maintaining the mold at a temperature in the range of approximately 150°-180° F.; and (d) urging said die toward said mold with a pressure of at least 2000 pounds per square inch of window area.
Claim 8
Dependent Claim
27 words
The method according to claim 5 in which said material is compressed by said die to a thickness at least 60% that of said foamed sheet material.
Claim 9
Dependent Claim
55 words
The method according to claim 5 in which the step of heating the material is accomplished by radiant heat of an intensity such that the resulting rate of heating produces a surface temperature in the range of approximately 275°-300° F. within a time range in which said heating produces insignificant cell rupture in said material.
Claim 10
Dependent Claim
20 words
The method according to claim 7 in which said material is polystyrene of a thickness less than approximately 30 mils.
Claim 11
Dependent Claim
31 words
The invention according to claim 7 in which said rate of heating produces a surface temperature in the range of approximately 275°-300° F. within a time range of approximately 7-14 seconds.
Claim 12
Dependent Claim
35 words
The method according to claim 5 including the step of thermoforming said sheet material against said mold beyond said region contemporaneously with the production of said transparent window to produce a component of box-like configuration.
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) | 1991-03-01 | 1991-08-31 | 1992-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-01 | 1995-08-31 | 1996-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-01 | 1999-08-31 | 2000-03-01 | $7700.00 | Window Closed / Lapsed |