Corner structure and blank for a tray

A tray formed from paperboard includes a quadrilateral main panel having right angle corners, a pair of end panels foldably joined respectively to opposite end edges of the main panel, a pair of side panels foldably joined respectively to opposite side edges of the main panel, a major web panel foldably joined to each end edge of each of said end panels, a minor web panel foldably joined to each end edge of each side panel, each major and each minor web panel being foldably joined to each other at each corner of the main panel along a common fold line, each major web panel having a major angle of approximately fifty-seven degrees defined by the common fold line and by the adjacent end edge of the associated end panel and each minor web panel having a minor angle defined by its common fold line and by the adjacent end edge of the associated side panel, the side and end panels being approximately perpendicular to the main panel and the major and minor web panels being disposed in the flat face contacting relation to each other, and adhesive means securing a part of each major web panel to the end of the associated side panel so as to secure the associated minor web panel therebetween.

TECHNICAL FIELD 
This invention relates to trays formed of paperboard and which are used in 
shipping, handling and display of secondary packages in which a plurality 
of primary packages are disposed. 
BACKGROUND ART 
U.S. patent application Ser. No. 102,353 filed Sept. 29, 1987, now U.S. 
Pat. No. 4,747,487 issued 5/31/88 and owned by the owner of this invention 
discloses an end loaded carton having a web panel at each bottom corner of 
the carton for insuring tightness of the carton about a group of articles 
packaged therein. This carton is formed from a blank of the wrap-around 
type. 
U.S. Pat. No. 4,558,816 issued Dec. 17, 1985 and owned by the assignee of 
this invention discloses a secondary container in which a plurality of 
primary packages are disposed for shipment and display at points of 
purchase. 
SUMMARY 
According to this invention, a shipping tray preferably is formed of 
paperboard and is used to transport, warehouse and display at points of 
purchase a plurality of secondary packages such as those disclosed in the 
above mentioned U.S. Pat. No. 4,558,816. 
According to this invention in one form, a tray is provided comprising a 
quadrilateral main panel having right angle corners together with pairs of 
side and end panels foldably joined respectively to opposite side and end 
edges of said main panel, a major web panel foldably joined to each end 
edge of each of the end panels, a minor web panel foldably joined to each 
end edge of each of said side panels, each of said major and of said minor 
web panels being foldably joined to each other at each corner of the main 
panel along a common fold line which extends outwardly from each corner of 
the main panel, each major web panel having a major angle defined by the 
associated common fold line and by the adjacent end edge of the adjacent 
end panel, the minor web panel at each corner of the tray having a minor 
angle defined by the associated common fold line and by the adjacent end 
edge of the associated side wall, the side and end walls being disposed in 
perpendicular relation to the main panel and the major and minor web 
panels at each corner of the tray being disposed in flat face contacting 
relation to each other and with the minor web panels interposed between 
the major web panels at each corner of the tray and the adjacent end of 
the associated side panel.

BEST MODE OF CARRYING OUT THE INVENTION 
With reference to FIG. 1 the numeral 1 designates a main panel of 
quadrilateral configuration and having right angle corners. Side panel 2 
is foldably joined to main panel 1 along a fold line 3. Similarly side 
panel 4 is foldably joined to main panel 1 along a fold line 5. End panel 
6 is foldably joined to main panel 1 along fold line 7 and end panel 8 is 
foldably joined to main panel 1 along fold line 9. From FIG. 1 it is 
apparent that end panels 6 and 8 are of rectangular configuration. 
Web structures at each corner of main panel 1 are identical. These web 
structures include major web panels 10, 11, 12 and 13. Each web structure 
also includes a minor web panel such as 14, 15, 16 and 17. 
Since all of the corner structures are identical only the corner structure 
comprising major web panel 13 and minor web panel 17 is here described in 
detail. 
As is apparent from FIG. 1 major web panel 13 is foldably joined to the 
adjacent end edge X of end panel 8 while minor web panel 17 is foldably 
joined to the adjacent end of side panel 4 along fold line Z. The web 
panels 13 and 17 are foldably joined to each other along a common fold 
line Y. 
It is vital that trays formed according to this invention effectively grip 
secondary packages such as P1 and P2 as shown in FIG. 2. It is vital 
therefore that the angular relationships taught by this invention be 
utilized. For example, the angular relation between fold line X and the 
common fold line Y is preferably approximately fifty-seven degrees and the 
angle between fold line Z and common fold line Y is approximately 
forty-nine degrees. These angular relationship insure snug gripping of the 
primary packages such as P1 and P2. 
Where primary packages include corners which are slightly bevelled, it is 
desirable to incorporate crease lines such are designated by the numerals 
18, 19 and 20 and 21. 
In order to form the set-up and loaded tray as shown in FIGS. 2 and 3, a 
blank such as FIG. 1 is fed into position and packages such as P1 and P2 
are deposited atop main panel 1. Thereafter web structures at the corners 
of the blank are pushed upwardly causing initial folding along common fold 
lines such as Y and elevation of the end panels 6 and 8. Continued 
manipulation of the web structures causes complete collapse thereof so 
that each minor web panel is interposed between the adjacent end of the 
associated side wall and its associated major web panel. The structure is 
maintained in this position by means of adhesive indicated by stippling in 
FIG. 2 which is applied either to the outer surface of major web panel 
such as 13 or to the inner corner of side wall such as 4. Of course 
similar activity occurs at all corners of the tray. The triangular 
bevelled panels in FIG. 2 are indicated by numerals 18a and 21a and are 
used where the secondary packages have bevelled corners. Where the 
secondary packages have square corners, the bevelled panels 18a, 19a, 20a 
and 21a are not used as shown in FIG. 3. An end view of FIG. 3 is not 
shown since such a view would simply show rectangular end panel such as 8 
and the upper part of P2 which would be rectangular. 
With the tray and its associated packages assembled as shown in FIGS. 2 and 
3, transport and stacking of packages are greatly facilitated. Since the 
tray side and end panels and web structures tightly grip the associated 
packages P1 and P2, the whole assembly is rendered very stable and 
precludes toppling when stacked in tiers in a warehouse or at a point of 
purchase. Also the bottom main panel of each tray in upper tiers tends to 
protect the tops of secondary packages disposed in lower tiers. Since a 
tray formed according to this invention preferably is formed of kraft 
paperboard rather than of corrugated board, any tendency of corrugated 
board to collapse due to excessive moisture or undue strain is largely 
eliminated according to one feature of this invention.