US 3810574 A
A self-locking tray formed from a unitary blank of foldable paperboard having bottom, side and end walls with corner gusset members interconnecting the side and end walls and having portions disposed in interlocking engagement with end flanges at the upper ends of the tray.
Description (OCR text may contain errors)
United States Patent [191 Gardner May 14, 1974 SELF-LOCKING TRAY 2,768,776 10/1956 Weiss 229/31 FS  Inventor: Jeffrey M. Gardner, Moline, Ill.
Primary Examiner-William i. Price  Assignee: Container Corporation of America, Assistant Examiner Douglas Farrow Chicago, Ill. Attorney, Agent, or Firm-Carpenter, Ostis &  Filed: Oct. 16, 1972 Lindberg  Appl. No.: 297,846
 ABSTRACT 52 U.S. Cl 229 31 F8, 229 43 Int CL 865d 2 A self-locking tray formed from a unltary blank of  Field 34 R 32 foldable paperboard having bottom, side and end walls Q l 229/51 with corner gusset members interconnecting the side and end walls and having portions disposed in inter-  References Cited locking engagement with end flanges at the upper UNITED STATES PATENTS ends of the tray 3,162.350 12/1964 Miller 229/31 FS 4 Claims, 5 Drawing Figures SELF-LOCKING TRAY This invention relates to an improvement in paperboard trays of the type used to contain produce or other articles. The tray may be used with or without a cover. The tray disclosed and claimed in this application represents an improvement over a similar type tray disclosed in US. Letters Pat. No. 2,754,046. The invention is designed to provide an improved leakproof corner construction and also to provide an improved interlocking relationship between the side and end walls of the tray and the end flanges of the tray.
An object of the invention is to provide an improved self-locking tray formed from a unitary blank of foldable paperboard having bottom, side, and end walls with corner gusset members interconnecting these walls and also having relatively narrow end flanges at the ends of the tray connected to upper portions of the tray end walls.v
A more specific object of the invention is the provision, in a tray of the type described, of gusset members interconnecting the end and sidewalls of the tray and having portions folded in. face-to-face relation against the sidewalls of the tray, and which also include flaps disposed to extend between upper and lower panels of tray end flanges.
These and other objects of the invention will be apparent from an examination of the following description and drawings, wherein:
FIG. 1 is a perspective view of a tray embodying features of the invention;
FIG. 2 is a plan view of the blank from which the tray illustrated in FIG. 1 may be formed;
FIGS. 3 and 4 are fragmentary sections taken on lines 3-3 and 4-4, respectively, of the structure illustrated in FIG. 1; and
FIG. 5 is a fragmentary, enlarged, plan view of a portion of the structure illustrated in FIG. 1.
It will be understood that, for purposes of clarity, certain elements have been intentionally omitted from certain views where they are believed to be illustrated to better advantage in other views.
Turning now to the drawing for a better understanding of the invention, it will be seen that the assembled tray illustrated in FIG. 1 may be formed from the unitary blank B of foldable paperboard illustrated in FIG. 2 of the drawings.
Although the tray in the drawings is illustrated with an open top, without a cover, it should be understood that thetray may be used with a conventional cover of the type having a top wall and side and end walls depending therefrom.
As thus seen in FIG. 2, the tray includes a generally rectangular bottom wall having pairs of opposed side and end walls 12 and 14 hingedly attached to the side and end edges of the bottom end wall along hinge lines 13 and 15, respectively, and folded at right angles to the bottom wall to extend upwardly therefrom.
The side and end walls 12 and 14 are connected to each other at each corner of the tray by a gusset member, indicated generally at 16, which is hingedly attached to the side and end walls along hinge lines 17 and 19, respectively. The structural details of the corner gusset members are described later in the specification.
At each end of the tray there is provided a relatively narrow horizontal end flange which has two functions.
One function is to increase the stacking strength of the tray and the other function is to provide an interlocking relationship between the end and side walls to add strength and rigidity of the tray construction.
Each end flange 20 includes an upper panel 22, hingedly attached at its outer edge along hinge line 21 to the upper edge of related end wall 14, and a lower flange panel 24, hingedly attached at its inner edge to the inner edge of upper panel 22 along a hinge line 25 which is preferably a double score line. Lower flange panel 24 may be provided at'its outer edge with one or more projections or lock tabs 26 which are disposed to extend through related slots 27 in an upper portion of the end wall 14 to provide interlocking engagement between the end flange and the end wall.
At opposite sides of the end flange upper panel 22 there are outwardly projecting extensions or retaining tabs 28 adapted to engage adjacent portions of the tray sidewall in a manner hereinafter described.
In order to provide leakproof corner construction for the corners of the tray, adjacent portions of each side and end wall 12 and 14, respectively, are connected by a corner gusset member 16, which includes a side section 30, hingedly attached along a fold line 17 to related side panel 12, and an end section 32 hingedly attached to related end panel 14 along a fold line 19. Side and end sections are hingedly attached to each other along a fold line 33 which is preferably a double score line extending outwardly from the related corner of tray bottom wall 10. Gusset member side section 30 is provided at its upper edge with a notch or recess 31, the purpose of which is described later in the application.
I-lingedly attached to the upper edge of each gusset member end section 32, along a fold line 37, is an end flap 34 which has a neck portion 36 hingedly attached along fold line 37 to the upper edge of gusset member end section 32. End flap 34 is provided at its outer edge with a lock tab 38, the purpose of which is described hereinafter.
To describe the assembly of the tray, which may be either done manually or on a machine, it will be understood that side walls 12 and the end walls 14 are folded upwardly about their respective fold lines to provide a box like structure. At the same time the gusset members 16 are folded so that their end and side sections, which are joined on fold line 33, are folded in face-toface relationship and against the outer surface of the end portion of the related sidewall 12. End flat 34 of the gusset member is then folded horizontally into the tray. The end flange panels are then folded inwardly at right angles to the end wall 14 of the tray with the gus- .set member end flaps being interposed between the upper and lower panels of the end flange and with the lock tabs' 26 of the end flange lower panel and with lock tabs 38 of the related end flaps 34 being received within the slots 27 formed in end walls 14 of the tray.
At the same time neck portion 36 of each gusset member end flap 34 and the end flange upper panel retaining tabs 28 are each positioned within the aligned slots 11 in the tray sidewall and 31 in the related gusset member side section, respectively, to provide an interlocking connection at the upper corners of the tray and thereby assure an extremely rigid corner construction for the tray.
Thus, it will be understood that the invention provides a self-locking tray with leakproof corners that is 0. horizontal upper end flanges at opposite ends of said tray, each comprising:
i. an upper flange panel foldably connected to the upper end edge of a related end wall and extending inwardly therefrom:
ii. a lower flange panel foldably connected at its inner edge to the inner edge of said upper flange panel and having its outer edge in interlocking engagement with said related end wall;
d. gusset members foldably interconnecting adjacent side and end walls, to provide leak-proof construction at the corners of said tray, and each comprismg: i. a pair of side and end gusset panels foldably connected to end and side edges of related side and end walls, respectively, and foldably connected to each other along a diagonal fold line extending outwardly and upwardly from the related corner of said bottom wall;
ii. said gusset panels being folded in face-to-face relation against the outer surface of said related sidewall;
iii. a locking flap foldably connected to the upper edge of said end gusset panel and disposed to extend inwardly between upper and lower panels of a related end flange.
2. A tray according to claim 1, wherein said lower flange panel has projecting outwardly from its outer edge at least one lock tab disposed to extend through an aperature in said related end wall to afford interlocking engagement between said flange and said related end wall.
3. A tray according to claim 2, wherein said lock tab extend beyond the outer surface of said related end wall for interlocking engagement with a removable tray cover.
4. A tray according to claim I, wherein said related side wall and said side gusset panel having aligned recesses in their upper edges for receiving a neck portion of said locking tab and a retaining tab of said upper flange panel.