Note: Descriptions are shown in the official language in which they were submitted.
1037853
One known interlocking means for securing a pair of
overlapping panels in interlocked relationship utilizes a locking
tab having projections thereon which is driven bodily through
a narrower locking aperture formed in the other panel. Such locking
means characteristically performs a secure locking function and
usually maintains the panels in tight interlocked relationship.
Thus when an interlock of this type is used in conjunction with
a wrapper type packaging blank, an efficient and secure packaging
operation is effected. In order to form a lock using such known
locking tabs and locking apertures, it is necessary as a practical
matter to provide reciprocatory plungers for forming the lock.
Since high speed packaging machines perform packaging manipulative
operations while the blank and its contents are moved at high
speed, the resulting machine for locking "punch-through" type
locks becomes somewhat complicated if it is to perform an effective
packaging operation.
Another known type of panel interlocking means utilizes
complicated so-called "heel and toe n locking means in one panel
which must be manipulated in precise synchronism with corresponding
apertures formed in the other panel and such manipulative operations
require a high degree of precision and frequently are characterized
by a degree of overtravel which, when the locking operation is
;~i completed, allow the lock components to relax somewhat and thereby
result in loosening and insecurity of wrapper type packages.
According to this invention an improved panel interlocking
means and method are provided which dispense with complicated high
speed moving components which customarily are required to perform
a locking operation of the "punch-through" type. With respect
to ~heel and toe" locks, the high degree of precision is avoided
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and the tendency of the interlocked panels to relax due to
overtravel is virtually eliminated. More specifically and in
accordance with one form of this invention, one panel to be inter-
locked with another panel is provided with a locking slit which
includes a base slit together with locking edges which diverge
from the ends of the base slit in a direction away from the
direction of locking movement of the panel to be interlocked
together with a positioning tab formed on the edge of the other
panel to be interlocked which is disposed adjacent a locking tab
struck from the other panel and folded into flat face contacting
relation with the positioning tab. Thereafter, both the positioning
tab and the locking tab are inserted into the locking slit by
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generally parallel motion of one panel relative to the other panel
so that after a predetermined degree of overlap which is determined
by engagement of the positioning tab side edges with the ends ;~
of the locking edges of the locking slit, the locking tab swings
outwardly and occupies an angular position relative to the .r -
positioning tab thereby to effect a secure interlocked relationship ~`
between the two panels which effectively precludes relative motion
therebetween in the planes thereof in any direction.
For a better understanding of the invention reference
may be had to the following detailed description taken in con-
- junction with the accompanying drawings in which FIG. 1 is a
per~pective view of a completed package formed according to this
invention and which is shown upside down from its normal orientation
in order to depict the interlocking means which normally aids
in forming a composite bottom panel FIG. 2 is a plan view of
a blank from which the package shown in FIG. 1 is formed; FIG. 3
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is an enlarged fragmentary view of portions of two panels which
are interlocked according to this invention and which show the
interlocking elements and the panels as these components appear
during an intermediate stage of an interlocking operation: FIG . 4
is a view similar to FIG. 3 and which shows the panels and their
locking elements in interlocking relationship; and in which
FIG. 5 is a view of the structure shown in FIG. 4 but which
, depicts the underneath surfaces of FIG. 4.
In the drawings the numeral 1 designates the main
central panel of the blank which ordinarily constitutes the top
wall of the finished package but which in FIG. 2 appears as
the bottom wall since FIG. 2 shows the package upside down from
its normal orientation. In panel 1, a pair of finger gripping
apertures 2 and 3 are formed in known manner and facilitate
carrying the package. A plurality of corner slits of known
construction are formed in the wrapper and are designated by
the numerals 4-9 inclusive. As is well known corner slits 4,
5 and 6 are disposed generally along the fold line 10 by which
side wall 13 is foldably joined to a side edge of main wall panel
1. Similarly corner slits 7, 8 and 9 are formed along fold `
line 12 by which side wall 11 is foldably joined to a side edge
of main wall panel 1. As is well known~ corner slits 4-9 inclusive
; receive portions of the packaged article such as cans C and
; aid in retaining the cans against dislodgment through the open
ends of the tubular structureO
A composite wall panel comprises a pair of lap panels
designated by the numerals 14 and 15 which are foldably joined ;-
to side walls 11 and 13 respectively along fold lines 16 and 17.
These lap panels 14 and 15 are interlocked according to this
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invention and are sometimes referred to herein as interlocked
panels or as lap panels.
- Corner slits 18, 19 and 20 are formed along fold line
17 while similar corner slits 21, 22 and 23 are formed along
fold line 16 and function in known manner to aid in retaining
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the cans C within the wrapper.
Panels 14 and 15 are interlocked according to one
form of this invention by means of locking slits such as are
formed in panel 15 and designated by the numerals 24, 25 and
26. Each locking slit includes a base slit such as 27 and a
pair of locking edges designated on slit 24 by the numerals 28
and 29 which define a guide tab 24a. These locking edges 28
and 29 are arranged 80 that their near ends interconnect with
tbe ends of base slit 27 and 80 that their opposite ends diverge
in a direction away from the portion of lap panel lS which is
r'' to be overlapped with lap panel 14 and which also diverge in
~ the general direction of the main portion of lap panel 15 and
J in a direction opposite from the general direction of planar
locking movement of panel 15 toward panel 14.
The other panol to be overlapped is designated by the
numeral 14 and i8 provided along its end edge with a plurality
08 positioning tabs designated by the numerals 30, 31 and 32.
Each of these positioning tabs is provided as is indicated in
connection with tab 30 with a pair of outwardly convergent side
edge portions designated by the numerals 33 and 34. In addition
and in accordance with a feature of this invention, a plurality
of locking tabs generally designated by the numeral~ 35, 36
and 37 are ~truck from the panel 14 and are foldably joined
thereto by their respective hinge lines 38, 39 and 40. Each ;~
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locking tab such as 35, 36 and 37 is provided with angularly
related side edge portions such as are designated by the numerals
41 and 42 in connection with locking tab 35. Preferably the
locking tab 35 is aligned with positioning tab 30 and the hinge
line 38 is parallel with the end edge of positioning tab 30.
The locking tab 35, as disposed in the blank, extends in a
direction opposite to the outwardly projecting positioning tab
30 and is of such length that tab 35 projects beyond the end
- edge of tab 30 when folded to the position shown in FIG. 3. The
angularly related side edges 41 and 42 of tab 35 intersect the
hinge line 38.
In order to form the package shown in FIG. 1 from the
blank shown in FIG. 2, the main panel 1 is dispoeed in contact
with corresponding ends of the cans "CN and the side walls 1}
: and 13 are folded alongside the cans as is well known. Thereafter `~
the lap panels 14 and 15 are folded along their respective fold
lines 16 and 17 into positions of approximate contact with the
enas of the cans ~C" which are opposite from the ends which are
in contact with main panel 1. ~hereafter the panels 14 and 15 :`
are secured together in interlocking relationship according to ;;:
this invention.
The fragments of panels 14 and 15 which are shown in -~ :
FIG. 3 and which incorporate locking slot 24 and its associated
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guide tab 24a are moved toward each other in parallel planes " ~ -
after the locking tab 35 is driven downwardly out of the plane
of panel 14 and folded along its hinge line 38 into flat face ~ -
contacting relation with the positioning tab 30. With guide ~ .
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tab 24a elevated slightly as shown in FIG. 3, locking tab 35
is disposed in overlying flat face contacting relationship with . ~;
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- respect to the adjacent edge portion of panel 15 and i~ interpo~ed
between positioning tab 30 and the adjacent edge portion of panel
15. Continued movement of panels 14 and 15 toward each other
in approximately parallel planes and with the guide tab 24a ~-
slightly elevated as shown in FIG. 3 causes both the positioning
tab 30 and the locking tab 35 to slide underneath the guide tab
24a. The degree of overlap which is to be effected is determined
by engagement of side edge 33 of positioning tab 30 with the end
28a of locking edge 28 and by engagement of side edge 34 of
positioning tab 30 with the end 29a of locking edge 29.
During movement of positioning tab 30 and of locking ;~
tab 35 into locking slit 24, locking tab 35 is disposed in flat
face contacting relationship with respect to positioning tab 30.
After the parts occupy their fully overlapped position with ;~
edges 33 and 34 in engagement of the ends 28a and 29a respectively
of locking edges 28 and 29, locking tab 35 swings downwardly
as viewed in FIG. 3 and in a direction away from positioning ~-
tab 30 due to the inherent bias or ~fight" of the material
which constitutes panel 14 and which is effective to cause
locking tab 35 to occupy an angular position relative to panels
14 and 15 a~ i8 shown in FIG. 5. When so disposed, side edge
portion 41 of locking tab 35 is in engagement with locking edge
28 and side edge portion 42 of locking tab 35 is in engagement
with locking edge 29 nqt ~hown in FIG. 5 since this edge is
disposed behind locking tab 35. -
When the lock is completed as is shown in FIGS. 4 and
5, panels 14 and 15 are effectively locked against movement in
the planes thereof in any direction. For example as depicted
in FIGS. 4 and 5, panel 14 is precluded from moving to the left -
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relative to panel 15 due to engagement of side edge 33 of
positioning tab 30 with the end 28a of locking edge 28 and by
side edge portion 34 of positioning tab 30 which engages end
29a of locking edge 29. Up and down motion of panel 14 relative
to panel 15 is prevented as shown in FIG. 5 because of the angular
disposition of locking tab 35 relative to panel 15 and due to
the fact that hinge line 38 of locking tab 35 is approximately
equal to the length of base slit 27 so that relative vertical
motion of panels 14 and 15 is prevented.
Motion of panel 14 toward the right as viewed in
FIG. 5 relative to panel 15 is precluded by engagement between
side edge portions 41 and 42 of locking tab 35 with the portions
of locking edge 28 and 29 which are adjacent to base slit 27.
Thus as is apparent, panels 14 and 15 are effectively
secured together in fixed overlapping relationship according to ~ -~
the invention. Furthermore as panels 14 and 15 are drawn toward r " ` ,
each other from the position shown in FIG. 3 to that shown in ~-
FIG. 4, the fully overlapped condition of the panels is determined
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and virtually no relaxation occurs after the lock is formed,
as shown in FIGS. 4 and 5. Since the parts do not change positions
after the desired degree of overlap is achieved, swinging movement -
~of locking tab 35 out of its position of face contacting
relationship with positioning tab 30 and into the position shown
in FIG. 5, completes the package and forms a secure interlock
according to this invention with little, if any, relaxation in
wrapper tension.
Interlocking of positioning tabs 31 and 32 with locking
slots 25 and 26 respectively and via locking tabs 36 and 37
respectively is effected in a manner identical to the locking
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1037~53
action of positioning tab 30, locking slot 24 and locking tab 35.
It is apparent that no reciprocatory machine parts are
required to effect this lock and that the lock may be formed
completely by static guides which engage the various components
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- and which perform manipulative operations as is obvious from
- the nature of the interloc~ing means and method according to
this invention following swinging movement of locking tab such
as 35 out of the plane of panel 14 and the slight movement of
guide tabs such as 24a out of the plane of panel 15 which movements
. 10 can be effected readily by rotary radial elements which are
well known in the art.
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