US3648883A

US3648883A - Tray

Info

Publication number: US3648883A
Application number: US889513A
Authority: US
Inventors: Orville J Bridenstine
Original assignee: Phillips Petroleum Co
Current assignee: DURACO INDUSTRIAL PRODUCTS Inc
Priority date: 1969-12-31
Filing date: 1969-12-31
Publication date: 1972-03-14
Anticipated expiration: 1989-03-14
Also published as: CA928229A

Abstract

A tray comprising upstanding side and end walls and a gridwork bottom disposed between the lower edge portions of said walls. Said gridwork bottom is comprised of intersecting struts which form rows of rectangles generally parallel with said walls. Each of said walls terminates at its upper edge to an outwardly extending turned-down flange which extends around the upper periphery of the tray. Said rows of rectangles have different dimensions which contribute to the rigidity and strength of the tray.

Description

United States Patent Bridenstine 5] Mar. 14, 197 2 [54] TRAY FOREIGN PATENTS OR APPLICATIONS [72] Inventor: Orville J. Bridenstiue, Wayzata, Minn. 241,341 7/1965 Austria ..220/21 [73] Assignee: Phillips Petroleum Company Primary Examiner wmiam T Dixson, JL [22] Filed: Dec. 31, 1969 Assistant Examiner-James R. Garrett 21] App1.No.: 889,513 Wm-hung and Quigg [57] ABSTRACT I v n I I n a 1 a a a I n I I l n a A a [58] Fieid o h 220/66 21 83 work bottom disposed between the lower edge portions of said Searc walk Said gridwork bottom is comprised of imemcfing struts which form rows of rectangles generally parallel with said [56] References cued walls Each of said walls terminates at its upper edge to an out- UNITED STATES PATENTS wardly extending turned-down flange which extends around the upper periphery of the tray. Said rows of rectangles have 1% 5 2:1

different dimensions which contribute to the rigidity and a .ustren of the a 3,265,237 8/1966 Pache et al. ..220/21 8th y 3,351,228 11/1967 Huisman ..220/66 17 Claims, 5 Drawing Figures NZ} Zn.

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INVENTOR.

O. J. BRI DENSTINE BY 7, WM,

ATTORNEYS PATENTEUHAR 14 I972 SHEET 3 BF 3 FIG. 4

INVENTOR. O. J. BRIDENSTINE BY 7M W 77 A TTORNEVS TRAY Trays of various kinds have been widely employed in moving commodities, e.g., foodstuffs, from one location to another. It is highly desirable that said trays be of a durable, rigid, lightweight structure, be easy to handle in use, be easy to store when not in use, be of a simple and inexpensive construction which is easy to manufacture, and be economical in cost, regardless of size. Few, if any, trays meeting all of the above requirements have been provided by the prior art.

The trays disclosed and claimed in copending application, Ser. No. 716,284, filed Mar. 20, 1968, now U.S. Pat. No. 3,494,502, solve the above-described problem by providing a tray which meets all the above requirements. The trays of said copending application and the trays of the present invention are provided with a gridwork bottom which is comprised of intersecting struts, preferably generally T-shaped and an outwardly extending turned-down flange which extends around the periphery of the tray. Said gridwork bottom and said flange cooperate to impart rigidity, durability, and other advantages to the tray, during both the manufacture and subsequent use thereof. The trays of the present invention include structural changes in said gridwork bottom, and preferably also in said flange, which cooperate to impart greater rigidity, greater strength, greater durability, and other advantages to the tray, both during manufacture and subsequent use thereof. Thus, the trays of the present invention are an improvement over the trays of said copending application.

An object of this invention is to provide an improved tray which can be employed to transport commodities from one location to another. Another object of this invention is to provide an improved tray which is of a durable, rigid, lightweight structure, is easy to handle, is easy to store when not in use, is of a simple and inexpensive construction which is easy to manufacture, and which is economical in cost. Another object of the invention is to provide an improved tray which not only readily nest with other like trays, but which will also readily nest with other generally similar but unlike trays. Another object of the invention is to provide an improved tray possessing the above-described advantages and which is adapted to be handled manually or by mechanical means. Other aspects, objects, and advantages of the invention will be apparent to those skilled in the art in view of this disclosure.

Thus, according to the invention, there is provided in a tray comprising, a pair of upstanding opposed first walls, a pair of upstanding opposed second transverse walls connected to said first walls along the upstanding edges thereof, an outwardly extending turned-down flange joined to the upper edges of said walls and extending around the periphery of said tray, and a gridwork bottom connected to the lower edge portions of said first walls and said second walls to provide a generally rectangular open top structure, the improvement of a gridwork bottom comprising: a plurality of intersecting struts which form a plurality of rectangles arranged in rows generally parallel with said walls; said rows of rectangles including a plurality of outer rows of rectangles; a plurality of intermediate rows of rectangles, adjacent said outer rows, and the rectangles therein each having at least one dimension which is greater than a like measured dimension in the rectangles in said outer rows; and at least one central row of rectangles, adjacent said intermediate rows, and the rectangles therein each having at least one dimension which is greater than a like measured dimension in the rectangles in said intermediate rows.

FIG. 1 is a plan view illustrating features of the improved trays of the invention and showing a fragment of the gridwork bottom structure in detail.

FIG. 2 is a side elevation of a tray fabricated in accordance with the invention.

FIG. 3 is a cross section taken along the line 33 of FIG. 1, and shows in dotted lines the nesting relationship of trays of the invention.

FIG. 4 is a bottom view of a corner of the tray illustrated in FIG. I.

FIG. 5 is a bottom view of a comer of another tray of the invention.

Referring now to the drawings, wherein like reference numerals are employed to denote like elements, the invention will be more fully explained. In FIG. 1 there is illustrated a generally rectangular tray 10 comprising a pair of upstanding opposed first or

side walls

12 and 12. A pair of upstanding opposed second or

end walls

14 and 14 are disposed transverse to said first walls and are connected to said first walls along the upstanding edges thereof. A gridwork bottom is connected to the lower edge portion of said first walls and said second walls to provide an open top structure. Said gridwork bottom is comprised of a plurality of intersecting struts which are preferably T-shaped and are disposed with the crossbar of said T facing the open top of the tray. An outwardly extending turned-down flange I8 is joined to the upper edge of each of said walls and extends around the upper periphery of the tray. Preferably, the upper inner edge 20 of said walls is arcuate and terminates in an essentially flat surface 22 on the top of said flange 18 (see FIG. 3).

In one preferred embodiment, said gridwork bottom comprises a first plurality of struts 24, preferably T-shaped, which are disposed generally parallel to said second walls 14 and 14', are spaced apart from each other, and extend between said pair of

first walls

12 and 12. A second plurality of struts 26, preferably T-shaped, are disposed generally parallel to said

first walls

12 and 12, are spaced apart from each other, and extend between said pair of

second walls

14 and 14. Said struts 24 integrally intersect said struts 26 at substantially 90 angles to form a plurality of rectangles. A third plurality of struts 28, preferably T-shaped, are provided with each one extending substantially diagonally across one of each of said rectangles. A fourth plurality of struts 30, preferably T- shaped, are provided with each one extending substantially diagonally across one of each of said rectangles in a direction to integrally intersect said other diagonally extending struts 28 at approximately the center of the rectangles as illustrated in the drawings. It will be noted that said rectangles are arranged in rows generally parallel with the side or end walls and that said side or end walls form one side of the outer rows of rectangles.

Said rows of rectangles in the tray include a plurality of outer rows of rectangles, running in each direction parallel with the walls of the tray. As here illustrated, said outer rows of rectangles are designated in the drawing by the reference letters A and H for the transverse rows, and A and H for the longitudinal rows. Preferably, each of said outer rows of rectangles is adjacent one of said

tray walls

12, 12, 14 or 14, as shown, and at least one side of each of said outer rectangles is formed by one of said tray walls. It is within the scope of the invention to omit either the outer rows A and H, or the outer rows A and H. Said rows of rectangles in the tray also include a plurality of intermediate rows of rectangles. As here illustrated, said intermediate rows of rectangles are designated in the drawing by the reference letters B and G transversely of the tray, and B and G longitudinally of the tray. Said intermediate rows of rectangles B, G, B, and G are positioned adjacent said outer rows A, H, A, and H, respectively, and each rectangle therein has at least one dimension which is greater than a like measured dimension in the rectangles in said outer rows A, H, A and H. Said intermediate rows of rectangles start and end inside of said outer rows of rectangles when a said outer row is provided on all four sides. It is within the scope of the invention to omit either the intermediate rows B and G or the intermediate rows B and G. It is also within the scope of the invention to include more than four rows of intermediate rectangles. It is preferred to fabricate the tray symmetrically. Said rows of rectangles in the tray also include at least one central row of rectangles. As here illustrated, said central row(s) of rectangles define a central area which is cornered by the rectangles C-C, C-F', F'-F, and F-C'. It is within the scope of the invention to include any number of said central rows of rectangles, either vertical or horizontal, in said central area, and any number of rectangles in each row. It is preferred to fabricate the tray symmetrically. Said central row(s) of rectangles are positioned adjacent said intermediate rows of rectangles, and each rectangle therein has at least one dimension which is greater than a like measured dimension in the intermediate rows of rectangles.

The above-described dimension and Like measured dimension are measured in the same direction. For example, referring to the upper left-hand corner of FIG. 1, the distance between wall 12 and the first horizontal strut designated 26 defines one dimension of the rectangles in outer longitudinal row A, the distance between said first strut 26 and the second strut designated 26 defines one dimension of the rectangles in intermediate row B, and the distance between said second strut 26 and the third strut designated 26 defines one dimension of the central rectangles. It will be noted that said central rectangle dimension is greater than said intermediate rectangle dimension, and said intermediate rectangle dimension is greater than said outer rectangle dimension.

The above-described feature of the invention of providing different dimensions on said outer, said intermediate, and said central rectangles contributes markedly in a number of ways to the overall rigidity and strength of the trays of the invention. Said feature makes possible the concentration of structural members adjacent the edges of the tray where it is most needed. Furthermore, said concentration of structural members is carried out in a most effective manner to provide both strength and rigidity. It will be noted that the

diagonal struts

28 and 30 are essentially parallel to each other in the abovedescribed central area of the tray. However, outside said central area said

diagonal struts

28 and 30 diverge from the parallel. This divergence results in said diagonal struts curving, in eflect, across the corner portions of the tray. Said curving, or divergence, of the diagonal struts markedly improves the distribution of stresses in a loaded tray, and essentially eliminates all tendency for empty trays to warp.

If desired, said gridwork bottom can be coved upwardly a small distance, e.g., one-sixteenth to one-eighth inch, from the outer edge toward the center of the tray. This will provide increased accommodation for heavier, loads, i.e., without causing the bottom to sag.

Preferably, said first plurality of struts can include a pair of reinforcing struts 32, also preferably T-shaped, which are each spaced apart respectively from one of said second walls 14 and I4, and generally bisect the rectangles in the respective outer rows of rectangles which are adjacent to said walls 14 and I4. Said reinforcing T-shaped struts 32 integrally intersect said diagonally extending

struts

28 and 30 at the intersections of same at approximately the center of said rectangles. Similarly, said second plurality of struts can also include a pair of T- shaped reinforcing struts 34 which are each spaced apart respectively from one of said

first walls

12 and 12, and generally bisect the rectangles in the respective outer rows of rectangles which are adjacent to said

walls

12 and 12. Said reinforcing struts 34 also integrally intersect said diagonally extending

struts

28 and 30 at the intersection of same at approximately the center of said rectangles. Said second plurality of struts can also include a second pair of reinforcing struts 36, also preferably T-shaped, each extending between said

second walls

14 and 14, each disposed generally parallel to said

first walls

12 and 12, and each generally bisecting the rectangles in one of said intermediate rows of rectangles B and G and integrally intersecting said diagonally extending

struts

28 and 30 at the intersection of same at approximately the center of said intermediate rectangles. If desired, a fifth plurality of struts 38, preferably T-shaped, can also be provided. Each one of the struts 38 included in said fifth plurality of struts extends from one of said intersections in said intermediate rectangles to one of said walls. It is also within the scope of the invention to provide more than one pair of said reinforcing struts 32. In such instances, the additional reinforcing struts would preferably be disposed in the row of rectangles adjacent the outer row of rectangles on each end of the tray. It is also within the scope of the invention to include a reinforcing strut, such as 32 and/or 34 and 36, in each row of rectangles across the tray. In such instances, said struts 38 includes in said fifth plurality of T-shaped struts would become the end sections of reinforcing struts like

struts

32, 34, or 36, as the case may be.

The above-described reinforcing struts increase the stiffness and stability of the tray. A primary effect is the marked stiffening of the rim of the tray. This effect also extends out into the gridwork structure of the tray bottom. This reinforced structure is particularly desirable in trays subjected to heavy loads.

Preferably, said opposed

first walls

12 and 12 slope inwardly toward each other from top to bottom, and said opposed

second walls

14 and 14 slope inwardly toward each other from top to bottom. The extent to which the trays will nest one within another will be determined by the thickness and the degree of slope of said side and end walls. The taper or slope of the walls should be sufficient that the trays are easily withdrawn from nested position. Usually a slope within the range of from about 5 to about 25 from the vertical will be sufficient. While it is preferred that the trays be provided with sloping walls, it is within the scope of the invention for said walls to be disposed essentially vertical.

Said turned down flange 18 extends peripherally around the upper edge of the tray. If desired, the turned-down portion of said flange is provided with a plurality of spaced apart recesses or scallops therein (not shown) which extend upwardly from the lower edge of the turned-down portion of the flange. Said recesses provide convenient places for insertion of fingers, either hand or mechanical, to remove the trays from nested position, or to pick up the tray and transport it from one location to another. A plurality of spaced apart reinforcing ribs 40 are disposed between and connected to the turned-down portion of said flange 18 and the side wall adjacent thereto. Preferably, each of said ribs 40 has an essentially flat bottom surface 42 which terminates in an arcuate portion 44 adjacent the tray wall it is connected to. See FIG. 3. Said essentially flat bottom surface 42 and said essentially flat top 22 on flange 18 cooperate to provide improved weight distribution when the trays are nested.

The corners of the trays of the invention are preferably arcuate. If desired, a plurality of generally vertically extending spaced apart serrations 43 (see FIG. 4) can be formed in the turned-down portion of flange 18 which extends around the comer. Said serrations serve to strengthen said comers. A reinforcing rib 40 is preferably positioned between each of said serrations and is connected to the turned-down portion of said flange and the tray wall adjacent thereto. Said serrations 43 have been omitted in the embodiment illustrated in FIG. 5.

If desired, a plurality of generally vertically extending spaced apart serrations 45 can be formed in the turned-down portion of said flange 18. See FIG. 2. Usually, when said serrations 43 are omitted in the corners as in FIG. 5, said serrations 45 are also omitted. The improved trays of the invention can very frequently be used along with other unlike trays and the different trays nested with each other in the same stack. The essentially flat bottom surface 42 on the ribs 40 facilitates such nesting. This is a marked advantage to a tray user who wishes to convert his operations to the improved trays of the invention without the expense of immediately junking his old trays.

FIGS. 1, 4, and 5 illustrate the reinforcing island 46 which is integrally formed at the intersection between the various parallel and diagonally extending struts, e.g., said struts 24, said struts 26, said struts 28, and said struts 30, or said struts 34, said struts 32, said struts 28, and said struts 30. The top surface area of said reinforcing island can be varied over a wide range depending upon the strength and rigidity desired in the tray. Usually the area of said island will be within the range of from about 1.5 to 12, preferably 2 to 10, times the top surface area of one of said T-shaped struts. If desired, an opening 48 can be provided through said reinforcing islands. Said opening effects economies in material costs, reduces weight, and reduced both curing and cycle time in the molding operation. If desired, the upper corners of said struts can be slightly rounded. In some instances, this facilitates sliding of articles across the gridwork bottom, as in loading the tray. If desired, the bottom corners of the T crossbar can also be rounded. If desired, the T-shaped struts, e.g., 24 and 16, can increase in height from their outer extremity to the center of the tray.

Trays fabricated in accordance with the invention possess a number of advantages over trays of the prior art. The trays of the invention are of a durable, lightweight structure. This is an important consideration in the use of said trays. For example, said trays are particularly well adapted for transporting bakery goods, both within the baking shop and the delivery truck. The bakery goods can be placed on the trays and the trays then placed in racks which may be easily pushed around the shop. The trays can also be readily loaded onto racks in a delivery truck. The light weight of the trays is a distinct advantage in that handling of the trays is not only less tiring for personnel handling same but also reduces the load on trucks. Thus, lighter weight trucks can be employed with obvious savings in operating expenses. The relatively broad top surface of the T- shaped struts provides a surface across which the bakery goods can be easily moved, as by sliding, and provide a surface which essentially eliminates the marking of soft goods, such as rolls, etc.

The T-shaped construction of the struts in the gridwork bottom represents an important advance in the art. Not only is a relatively broad surface provided with the attendant advantages described above, but said construction also imparts increased strength and stability to the tray. The abovedescribed reinforcing islands also contribute materially to the strength and stability of the tray. These construction features make possible significant economies in material required for a given strength and stability in the tray structure. Thus, the tray has substantially all the advantages of a solid bottom tray without the disadvantages thereof, e.g., increased weight. The T-shaped structure is also easy to mold and easy to remove from the mold. The T-shaped structure of the struts cooperates in combination with the dimensions of the rectangles formed by said struts, the turned-down flange which extends around the periphery of the tray, and other structural features of the tray, to impart rigidity and stability to the tray during both the manufacture and subsequent use thereof.

The trays of the invention can be fabricated in any suitable manner known to the art. Injection molding, for example, is one presently preferred method for fabricating said trays. Said trays can be fabricated from any suitable material. High density polyethylenes are especially desirable materials from which to fabricate said trays. The high density polyethylene and other polyolefins prepared by the methods disclosed and claimed by .l. P. Hogan et al. in US. Pat. No. 2,825,721, issued Mar. 4, I958, are one group of presently preferred materials. Said trays can also be fabricated from butadiene-styrene copolymers, and other plastic materials. If desired, a reinforcing fibrous material, such as asbestos or glass fibers, can be incorporated in the plastic material. While the various plastics are presently preferred for the manufacture of the trays, it is within the scope of the invention to fabricate said trays from other materials, e.g., lightweight metals such as aluminum, reinforced pulp materials, etc.

As an example, one model of a tray fabricated in accordance with the invention had a length of about 26 inches, a width of about 22 inches, the largest rectangles formed in the gridwork bottom were about 3X3.5 inches, the top surface of the T-shaped struts was about 0.25 inch wide, and the side walls were about 1 inch in height. The remainder of the elements of the tray were generally proportional in size. These dimensions are given by way of example only, are not to be construed as limiting on the invention in any way, and all can be varied within the scope of the invention.

Herein and in the claims the word rectangular has been employed generically to include four-sided structures which are generally square and four-sided structures wherein one pair of sides is longer than the other pair of sides.

While certain embodiments of the invention have been described for illustrative purposes, the invention obviously is not limited thereto. Various other modifications will be apparent to those skilled in the art in view of this disclosure. Such modifications are within the spirit and scope of the invention.

lclaim:

1. In a tray comprising, a pair of upstanding opposed first walls, a pair of upstanding opposed second transverse walls connected to said first walls along the upstanding edges thereof, and a gridwork bottom connected to the lower edge portions of said first walls and said second walls to provide a generally rectangular open top structure, the improvement of the gridwork bottom comprising:

a plurality of intersecting struts which form a plurality of rectangles arranged in rows generally parallel with said walls; said rows of rectangles including at least two outer rows of rectangles, disposed with one said outer row adjacent one of said tray walls and another said outer row adjacent an opposing said wall, said rows each having a longitudinal dimension and a transverse dimension;

at least two intermediate rows of rectangles, disposed with one said intermediate row adjacent said one of said outer rows and another said intermediate row adjacent said another said outer row, and the rectangles therein each having one of a longitudinal dimension or a transverse dimension which is the same as the like measured longitudinal dimension or transverse dimension of said outer rectangles, with the other of said longitudinal dimension or said transverse dimension of said intermediate rectangles being greater than the like measured other dimension of said outer rectangles; and

at least one central row of rectangles; disposed adjacent said intermediate rows of rectangles, and the rectangles therein each having one of a longitudinal dimension or a transverse dimension which is the same as the like measured longitudinal dimension or transverse dimension of said intermediate rectangles and said outer rectangles, with the other of said longitudinal dimension or said transverse dimension in said central rectangles being greater than the like measured other dimension of said intermediate rectangles; whereby diagonals extending across said outer rectangles and said intermediate rectangles, between adjacent tray walls or between said central rectangles and a tray wall, form generally curved lines across said outer and said intermediate rectangles.

2. A tray according to claim 1 wherein:

said outer rows of rectangles are four in number and each one of said outer rows of rectangles is adjacent one of said tray walls, at least one side of said outer rectangles is formed by one of said walls, and said transverse dimension is measured inwardly from said tray wall;

said intermediate rows of rectangles are four in number and each one of said intermediate rows of rectangles is adjacent one of said outer rows of rectangles;

a plurality of said central rows of rectangles is disposed between said intermediate rows of rectangles;

an outwardly extending turned-down flange is joined to the upper edges of said walls and extends around the periphery of said tray; and

wherein said longitudinal dimension in said outer, said intermediate, and said central rectangles is the same.

3. A tray according to claim 2 wherein the upper inner edge of said tray walls is arcuate and terminates in an essentially flat surface on the top of said flange.

4. A tray according to claim 3 wherein:

a plurality of spaced apart reinforcing ribs are disposed between the turned-down portion of said flange and the tray wall adjacent thereto;

each of said ribs has an essentially flat bottom surface; and

said flat bottom surface terminates in an arcuate portion,

adjacent the tray wall it is connected to, which has a curvature essentiaily the same as the arcuate surface of the upper inner edge of said tray wall.

5. A tray according to claim 4 wherein: said struts are generally T-shaped; the crossbar of said T is disposed facing the open top of said tray; and the vertical leg of said T is connected directly to said walls.

6. A tray according to claim 5 wherein said gridwork bottom is coved upwardly from the outer edge thereof toward the center of the tray.

7. A tray in accordance with claim 2 wherein said gridwork bottom comprises:

a first plurality of said struts spaced apart from each other, extending between said pair of first walls, and disposed generally parallel to said second walls;

a second plurality of said struts spaced apart from each other, extending between said pair of second walls, disposed generally parallel to said first walls, and integrally intersecting said first plurality of struts at substantially 90 angles to form said plurality of rectangles;

a third plurality of struts, each one of which extends substantially diagonally across one of each of said rectangles; and

a fourth plurality of struts, each one of which extends substantially diagonally across one of each of said rectangles in a direction to integrally intersect said firstmentioned diagonally extending struts at approximately the center of the rectangle.

8. A tray in accordance with claim 7 wherein:

said first plurality of struts includes a pair of reinforcing struts, each spaced apart respectively from one of said second walls and generally bisecting the rectangles in said outer row of rectangles adjacent thereto and integrally intersecting said diagonally extending struts at the intersection of same at approximately the center of said outer rectangles; and

said second plurality of struts also includes a pair of reinforcing struts, each spaced apart respectively from one of said first walls and generally bisecting the rectangles in said outer row of rectangles adjacent thereto and integrally intersecting said diagonally extending struts at the intersection of same at approximately the center of said outer rectangles.

9. A tray according to claim 8 wherein: said second plurality of struts further includes a second pair of reinforcing struts, each extending between said second walls, each disposed generally parallel to said first walls, and each generally bisecting the rectangles in one of said intermediate rows of rectangles and integrally intersecting said diagonally extending struts at the intersection of same at approximately the center of said intermediate rectangles.

10. A tray in accordance with claim 9 including, in further combination: a fifth plurality of struts, each one of which extends from one of said intersections in one of said intermediate rows of rectangles to one of said walls,

11. A tray according to claim 10 wherein, in each rectangle of said outer rows of rectangles, at least one end of each one of said diagonally extending struts is connected directly to the tray wall forming one side of the rectangle a small distance from the juncture point with said wall of a nondiagonally extending strut which forms another side of the rectangle.

12. A tray according to claim 11 wherein the upper inner edge of said tray walls is arcuate and terminates in an essentially flat surface on the top of said flange.

13. A tray according to claim 12 wherein:

each of said ribs has an essentially flat bottom surface; and

said flat bottom surface terminates in arcuate portion, ad

jacent the tray wall it is connected to, which has a curvature essentially the same as the arcuate surface of the upper inner edge of said tray wall. 14 tray according to claim 13 wherein: said struts are generally T-shaped; the crossbar of said T is disposed facing the open top of said tray; and the vertical leg of said T is connected directly to said walls.

15. A tray according to claim 14 wherein said gridwork bottom is coved upwardly from the outer edge thereof toward the center of the tray.

16. A tray in accordance with claim 15 wherein: a reinforcing island, having a top surface area within the range of from about 1.5 to 12 times the area of the top surface of one of said T-shaped struts, is formed at each intersection between the struts in said first plurality of struts, the struts in said second plurality of struts, and said diagonal struts; and an opening extends through each of said islands formed in or adjacent said inner rows of rectangles and said central rows of rectangles.

17. A tray in accordance with claim 16 wherein:

the corners of said tray are arcuate,

a plurality of generally vertically extending spaced apart serrations are formed in the turned-down portion of said flanges around said corner;

a reinforcing rib is positioned between each of said serrations and is connected to the turned-down portion of said flange and the tray wall adjacent thereto; and

a second plurality of generally vertically extending spaced apart serrations is disposed in the turned-down portion of said flange which extends along each of said walls.

Claims

1. In a tray comprising, a pair of upstanding opposed first walls, a pair of upstanding opposed second transverse walls connected to said first walls along the upstanding edges thereof, and a gridwork bottom connected to the lower edge portions of said first walls and said second walls to provide a generally rectangular open top structure, the improvement of the gridwork bottom comprising: a plurality of intersecting struts whicH form a plurality of rectangles arranged in rows generally parallel with said walls; said rows of rectangles including at least two outer rows of rectangles, disposed with one said outer row adjacent one of said tray walls and another said outer row adjacent an opposing said wall, said rows each having a longitudinal dimension and a transverse dimension; at least two intermediate rows of rectangles, disposed with one said intermediate row adjacent said one of said outer rows and another said intermediate row adjacent said another said outer row, and the rectangles therein each having one of a longitudinal dimension or a transverse dimension which is the same as the like measured longitudinal dimension or transverse dimension of said outer rectangles, with the other of said longitudinal dimension or said transverse dimension of said intermediate rectangles being greater than the like measured other dimension of said outer rectangles; and at least one central row of rectangles; disposed adjacent said intermediate rows of rectangles, and the rectangles therein each having one of a longitudinal dimension or a transverse dimension which is the same as the like measured longitudinal dimension or transverse dimension of said intermediate rectangles and said outer rectangles, with the other of said longitudinal dimension or said transverse dimension in said central rectangles being greater than the like measured other dimension of said intermediate rectangles; whereby diagonals extending across said outer rectangles and said intermediate rectangles, between adjacent tray walls or between said central rectangles and a tray wall, form generally curved lines across said outer and said intermediate rectangles.

2. A tray according to claim 1 wherein: said outer rows of rectangles are four in number and each one of said outer rows of rectangles is adjacent one of said tray walls, at least one side of said outer rectangles is formed by one of said walls, and said transverse dimension is measured inwardly from said tray wall; said intermediate rows of rectangles are four in number and each one of said intermediate rows of rectangles is adjacent one of said outer rows of rectangles; a plurality of said central rows of rectangles is disposed between said intermediate rows of rectangles; an outwardly extending turned-down flange is joined to the upper edges of said walls and extends around the periphery of said tray; and wherein said longitudinal dimension in said outer, said intermediate, and said central rectangles is the same.

4. A tray according to claim 3 wherein: a plurality of spaced apart reinforcing ribs are disposed between the turned-down portion of said flange and the tray wall adjacent thereto; each of said ribs has an essentially flat bottom surface; and said flat bottom surface terminates in an arcuate portion, adjacent the tray wall it is connected to, which has a curvature essentially the same as the arcuate surface of the upper inner edge of said tray wall.

7. A tray in accordance with claim 2 wherein said gridwork bottom comprises: a first plurality of said struts spaced apart from each other, extending between said pair of first walls, and disposed generally parallel to said second walls; a second plurality of said struts spaced apart from each other, extending between said pair of second walls, disposed generally parallel to said first walls, and integrally intersecting said first Plurality of struts at substantially 90* angles to form said plurality of rectangles; a third plurality of struts, each one of which extends substantially diagonally across one of each of said rectangles; and a fourth plurality of struts, each one of which extends substantially diagonally across one of each of said rectangles in a direction to integrally intersect said first-mentioned diagonally extending struts at approximately the center of the rectangle.

8. A tray in accordance with claim 7 wherein: said first plurality of struts includes a pair of reinforcing struts, each spaced apart respectively from one of said second walls and generally bisecting the rectangles in said outer row of rectangles adjacent thereto and integrally intersecting said diagonally extending struts at the intersection of same at approximately the center of said outer rectangles; and said second plurality of struts also includes a pair of reinforcing struts, each spaced apart respectively from one of said first walls and generally bisecting the rectangles in said outer row of rectangles adjacent thereto and integrally intersecting said diagonally extending struts at the intersection of same at approximately the center of said outer rectangles.

10. A tray in accordance with claim 9 including, in further combination: a fifth plurality of struts, each one of which extends from one of said intersections in one of said intermediate rows of rectangles to one of said walls.

13. A tray according to claim 12 wherein: a plurality of spaced apart reinforcing ribs are disposed between the turned-down portion of said flange and the tray wall adjacent thereto; each of said ribs has an essentially flat bottom surface; and said flat bottom surface terminates in arcuate portion, adjacent the tray wall it is connected to, which has a curvature essentially the same as the arcuate surface of the upper inner edge of said tray wall.

14. A tray according to claim 13 wherein: said struts are generally T-shaped; the crossbar of said T is disposed facing the open top of said tray; and the vertical leg of said T is connected directly to said walls.

17. A tray in accordance with claim 16 wherein: the corners of said tray are arcuate; a plurality of generally vertically extending spaced apart serrations are formed in tHe turned-down portion of said flange around said corner; a reinforcing rib is positioned between each of said serrations and is connected to the turned-down portion of said flange and the tray wall adjacent thereto; and a second plurality of generally vertically extending spaced apart serrations is disposed in the turned-down portion of said flange which extends along each of said walls.