US3917108A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plastic tray and method of making same
Assignee: Dare Plastics Inc
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Filing: 1972-02-22
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Granted: 1975-11-04
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Expires: 1992-02-22
Abstract
Abstract An open top tray having side walls and a bottom wall. The bottom wall is made from a matrix of interconnecting struts which are so configurated and sized that in the course of being molded they are prestressed into an upwardly bowed condition. This prestressing rigidifies the bottom of the tray as well as enables it to be maintained in an upwardly bowed condition from which it is deformed into a flat condition only when the tray is fully loaded. The side walls of the tray terminate in a horizontal flange which is reinforced by vertical ribs which extend between the side walls and the horizontal flange.
Inventors
- 👤 Paul G Thurman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:30
CPC Classifications
B; B65; B65D; B65D19/00; B65D19/0002; B65D1/00; B65D1/34; Y; Y10; Y10S; Y10S108/00; Y10S108/901
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
132 words
A molded plastic tray comprising side walls and a bottom wall, said bottom wall comprising an open gridwork of intersecting struts, at least some of said struts being T-shaped in cross section, said T-shaped struts having intersecting horizontal cross bars and vertical ribs, the cross bars of the T-shaped struts being located above the vertical ribs and forming the inside bottom surface of the tray, and the vertical ribs of said struts being approximately twice the thickness in cross section of said horizontal cross bars and being substantially greater in height than the width of said cross bars so that during molding of the tray, the cross bars solidify before the vertical ribs and cause the struts to be prestressed into a rigid condition which effectively resists vertical deflection of the bottom.
Claim 2
Dependent Claim
132 words
A molded plastic tray comprising side walls and a bottom wall, said bottom wall comprising an open gridwork of intersecting struts, at least some of said struts being T-shaped in cross section, said T-shaped struts having intersecting horizontal cross bars and vertical ribs, the cross bars of the T-shaped struts being located above the vertical ribs and forming the inside bottom surface of the tray, and the vertical ribs of said struts being approximately twice the thickness in cross section of said horizontal cross bars and being substantially greater in height than the width of said cross bars so that during molding of the tray, the cross bars solidify before the vertical ribs and cause the struts to be prestressed into a rigid condition which effectively resists vertical deflection of the bottom.
Claim 3
Dependent Claim
31 words
The molded plastic tray of claim 1 in which the side walls as well as the bottom wall are bowed upwardly as a result of the prestressed condition of the struts.
Claim 4
Dependent Claim
32 words
The plastic tray of claim 1 which further includes a flange located along the upper edge of each of said side walls, said flange being completely located in a substantially horizontal plane.
Claim 5
Dependent Claim
32 words
The plastic tray of claim 3 which further includes vertical ribs extending between said substantially horizontal flange and said side walls, said vertical ribs being operable to reinforce said substantially horizontal flange.
Claim 6
Dependent Claim
23 words
The plastic tray of claim 4 in which said substantially horizontal flange defines an included angle of approximately 105* with said side walls.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |