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Patent US4026457A successfully refreshed from Google Patents.
US4026457A
Expired / Lapsed
US
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Tray with raised dividers
Assignee: BP Corp North America Inc
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Filing: 1976-06-30
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Granted: 1977-05-31
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Expires: 1996-06-30
Abstract
Abstract Improved automatic machine made heatsealed overwraps on trays with interior self-contained compartments are achieved by having the top surfaces of the dividers for said compartments progressively project above the top surfaces of outside walls.
Inventors
- 👤 John C. Schubert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:00
CPC Classifications
B; B65; B65D; B65D1/00; B65D1/34; B65D1/36
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
55 words
A tray having a base, outside walls, a first surface comprising top surfaces of said outside walls, and an interior divided into self-contained compartments by a plurality of divider walls having a second surface comprising top surfaces of said divider walls, wherein the improvement comprises having said second surface progressively projecting above said first surface.
Claim 2
Dependent Claim
55 words
A tray having a base, outside walls, a first surface comprising top surfaces of said outside walls, and an interior divided into self-contained compartments by a plurality of divider walls having a second surface comprising top surfaces of said divider walls, wherein the improvement comprises having said second surface progressively projecting above said first surface.
Claim 3
Dependent Claim
29 words
The tray of claim 1 made from thermoplastic selected from the group consisting of polymers of at least one alpha-olefin of up to 8 carbons, polystyrene, polyester, and polyamide.
Claim 4
Dependent Claim
81 words
The tray of claim 1, wherein said tray is made by thermoforming and wherein the maximum projection above said first surface achieved by said second surface is determined by correlating the following: thickness of the plastic sheet used prior to being thermoformed, the particular plastic sheet used, the depth of draw in the thermoforming process, and the overall dimensions and configuration of the finished tray, so that during the heatsealing of an overwrap to top surfaces crack formation does not occur.
Claim 5
Dependent Claim
20 words
The tray of claim 2, wherein said maximum projection is in the range of about 1/32 to 1/8of an inch.
Claim 6
Dependent Claim
63 words
The food tray of claim 1, wherein the gradient describing the rate by which said second surface progressively projects above said first surface is limited to values which give rise to a smooth and gradual projection of said second surface above said first surface, whereby a uniform heatseal can be made over all top surfaces by means of machines which form heatsealed overwraps.
Claim 7
Dependent Claim
16 words
The food tray of claim 1, wherein said top surfaces of said outside walls are flanges.
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) | 1980-05-30 | 1980-11-29 | 1981-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-30 | 1984-11-29 | 1985-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-30 | 1988-11-29 | 1989-05-31 | $7700.00 | Window Closed / Lapsed |