US3950208A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making egg cartons
Assignee: Hexion Inc
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Filing: 1973-08-17
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Granted: 1976-04-13
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Expires: 1993-08-17
Abstract
Abstract A foamed plastic sheet is perforated medially before it is heated in an oven following which, it is conveyed between a pair of matching molds where a quad of egg cartons is formed in an upside down condition with locking lugs of a pair of cartons on one side of the perforated line facing the lugs of the other pair across the perforated line. Perforation of the sheet is made to relieve stress in the region where the lugs are formed.
Inventors
- 👤 Frank Eugene Pavuk
- 👤 Roger Henry Steiner
- 👤 Sumner Sheldon Feinstein
- 👤 Richard Joseph Venuti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:05
CPC Classifications
B; B29; B29C; B29C51/00; B29C51/02; B29C51/26; B29C51/266; B29C51/268; B65; B65D; B65D85/00; B65D85/30; B65D85/32; B65D85/324; B29K; B29K2105/00; B29K2105/04; B29L; B29L2031/00; B29L2031/712; B29L2031/7162; B29L2031/7168
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
80 words
Method for forming at least one pair of egg cartons from a foamed thermoplastic sheet comprising perforating the sheet medially to form a centerline, heating the sheet to render it sufficiently pliable for forming the egg cartons, feeding the sheet between matching molds, closing the molds to form the pair of egg cartons and moving mold elements into place following mold closure to form projections in the egg cartons, the projections being formed adjacent to said centerline of medial perforations.
Claim 2
Dependent Claim
80 words
Method for forming at least one pair of egg cartons from a foamed thermoplastic sheet comprising perforating the sheet medially to form a centerline, heating the sheet to render it sufficiently pliable for forming the egg cartons, feeding the sheet between matching molds, closing the molds to form the pair of egg cartons and moving mold elements into place following mold closure to form projections in the egg cartons, the projections being formed adjacent to said centerline of medial perforations.
Claim 3
Dependent Claim
36 words
Method of claim 1 wherein a quad of egg cartons is formed with projections sof two egg cartons on one side of the sheet facing projections of the other two egg cartons disposed across the sheet.
Claim 4
Dependent Claim
21 words
Method of claim 2 wherein the projections include a lug and a stcking depression on the front panel of the cover.
References Cited (Backward Citations)
US3326443A
Cited
US3475526A
Cited
US3519189A
Cited
US3572578A
Cited
US3640668A
Cited
US3651976A
Cited
US3670952A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-13 | 1979-10-13 | 1980-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-13 | 1983-10-13 | 1984-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-13 | 1987-10-13 | 1988-04-13 | $7700.00 | Window Closed / Lapsed |