U.S. patent number 3,616,943 [Application Number 04/858,746] was granted by the patent office on 1971-11-02 for stacking system.
This patent grant is currently assigned to W. R. Grace & Co.. Invention is credited to Delbert L. Brink.
United States Patent |
3,616,943 |
Brink |
November 2, 1971 |
STACKING SYSTEM
Abstract
A body such as a box may be stacked with substantial rigidity
and provided with the capability of spacing and staggering by
providing single and/or multiple rows of protuberances such as
beads on upper and lower surfaces arranged so that the beads nest
or interlock upon stacking.
Inventors: |
Brink; Delbert L. (South
Seattle, WA) |
Assignee: |
W. R. Grace & Co.
(Cambridge, MA)
|
Family
ID: |
25329084 |
Appl.
No.: |
04/858,746 |
Filed: |
September 17, 1969 |
Current U.S.
Class: |
206/508; 206/509;
206/821; 446/128; 206/511; 426/419 |
Current CPC
Class: |
B65D
21/0235 (20130101); Y10S 206/821 (20130101) |
Current International
Class: |
B65D
21/02 (20060101); B65g 001/14 () |
Field of
Search: |
;214/10.5 ;206/65 ;46/25
;220/97,97B ;217/42 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Forlenza; Gerald M.
Assistant Examiner: Werner; Frank E.
Claims
I claim:
1. A stackable body comprising; an upper surface and a lower
surface each of said surfaces being capable of adjacentwise
coincidence with at least one of them; at least one first row group
comprising at least one row of equally spaced protuberances; at
least one second row group comprising at least two rows of said
equally spaced protuberances; the row groups being mounted on pads
upon the body and oriented upon the surfaces so that upon stacking
by adjacentwise coincidence of the surface the protuberances of
each first row group are axially interposed between and in offset
contact with the protuberances of a second row group.
2. The stackable body of claim 1 wherein the protuberances are of
diminishing circular cross section and are equally spaced both
axially and transaxially of the rows.
3. The stackable body of claim 2 wherein the protuberances are
semispherical in shape.
4. The stackable body of claim 3 wherein the body is foamed
agglutinated polystyrene granules.
5. The stackable body of claim 4 wherein an average of at least
five granules extend across the greatest diameter of the
protuberances.
6. A stackable body comprising an upper and lower surface, each of
said surfaces being capable of adjacentwise coincidence with at
least one of them; at least one first row group comprising at least
one row of equally spaced protuberances; at least one second row
group comprising at least two rows of said equally spaced
protuberances; the row groups being oriented upon the surfaces so
that upon stacking by adjacentwise coincidence of the surfaces the
protuberances of each first row group are axially interposed
between and in offset contact with the protuberances of the second
row group and the protuberances are of diminishing circular cross
section are equally spaced both axially and transaxially of the
rows a distance such that the protuberances are interposed in
contact without bottoming on the surfaces.
7. The stackable body of claim 6 wherein the body is rectangular in
plan having a single planar upper surface and a single planar lower
surface and having row groups extending parallel to one dimension
of the rectangle along the edges thereof.
8. The stackable body of claim 7 further comprising a row group
extending centrally of the rectangle and parallel to the other row
groups.
9. The stackable body of claim 7 wherein the row groups are mounted
on pads upon the body.
Description
BACKGROUND OF THE INVENTION
The invention relates to stackable bodies in particular to
container boxes which are to be stacked wherein it is desired that
a rigid stack or formation of stacks be formed. In particular, the
invention relates to such bodies which may be stacked in staggered
or overlapped formation to an optional degree with or without
spaces between the bodies. In one particularly advantageous
embodiment, boxes molded of foamed, agglutinated polystyrene beads
are provided with the stacking means of the invention.
In the past it has been known to permit rigid stacking of bodies
such as container boxes by shaping them so that some portion of the
bottom of one container is captured by the top of another identical
container, or visa versa, as in nesting. One common form is where
the lower portion of the container is smaller than its upper
portion, as by being tapered, and the latter has a cavity for
receiving an identical container up to some desired depth. This
form is excellent for forming single stacks of empty containers
such as nested drinking cups. However, it is inefficient when it is
desired to stack filled containers or solid bodies since the space
needed to nest is not available for the basic purpose of the
container or body. Furthermore, this stacking means only permits
single stacks to be formed which must then, if a rigid multistack
formation is desired, be joined by some other means such as tying
or wrapping, e.g. if more than one stack is desired to be
transported. If spacing is desired between containers this can be
accomplished only by quite inconvenient spacers between stacks and
spacing is effectively impractical within a stack.
Some of these problems have been alleviated by another form of
stacking means in which projections or legs are provided at the
bottom corners of the container and mating cavities in the top
corners. This form permits spacing within a stack but is still
ineffective for multistack formations. In addition, in cases where
a high degree of rigidity or resistance to dislodgment is desired,
it is necessary that the projections and mating cavities be
relatively massive and deep thus consuming an undesirably large
amount of space.
Other severe disadvantages are that the projections or legs
interfere with conveyor systems, are easily broken especially if
the container is dropped on a corner; and require careful
preparation of the floor to assure equal support for all the legs.
The cavities of such systems are often found to contain dirt or
debris which interferes with proper functioning.
These and other problems are alleviated in the present invention as
will be seen by the following discussion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the top of a box embodying the
invention.
FIG. 2 is a perspective view showing the bottom of the box of FIG.
1.
FIG. 3 is a side view of the rows of interposed beads of the
embodiment of FIG. 1.
FIG. 4 is an end view of the rows of interposed beads.
FIG. 5 is an elevation view of boxes of FIG. 1 vertically
stacked.
FIG. 6 is a section view through line 6--6 of FIG. 3.
FIG. 7 is a side view of an alternate embodiment of the
invention.
FIG. 8 is an end view of the embodiment of FIG. 7.
FIG. 9 is an elevation view of boxes of FIG. 1 stacked with offset
and spacing.
FIG. 10 is a perspective schematic view of boxes embodying the
invention cross-stacked in a solid formation.
FIG. 11 is a plan view of matrix of FIG. 10.
FIG. 12 is an elevational partially schematic view of another
embodiment of the invention.
SUMMARY OF THE INVENTION
A stackable body is provided on upward- and downward-facing
surfaces with groups of protuberances oriented in rows wherein upon
stacking, the rows mate such that the protuberances of one row are
axially interposed and offset between the protuberances of another
row. The rows are parallel and the protuberances equally spaced so
that the bodies may be stacked vertically aligned or may be
staggered to form interconnected solid or spaced formations of
stacks.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2 a form of the invention is shown as
employed in a box 1 having an upper surface or top 2 and a lower
surface or bottom 4. The top 2 might typically be a removable cover
although that would have no consequence as regards the invention
except that the cover should be fairly well secured to the box.
Upon the top 2 is a series of pads 6 and upon the bottom 4 a series
of similar pads 8. Extending from each of the pads 6 are two
parallel rows 10 consisting of protuberances 12 in this particular
embodiment in the shape of semispherical beads which can be more
plainly seen by reference to FIGS. 3 and 4 and more particular
mention of which will be made later. Extending from each of the
pads 8 are three parallel rows 14 consisting of the same
protuberances or beads 12 as in the rows 10. The sets of two and
three rows may be conveniently referred to respectively as row
groups 10 and 14 or alternatively as matrices. The row groups 10
and 14 are oriented on the upper and lower surfaces 2 and 4
respectively so that when boxes 1 are stacked as shown in FIG. 5
the rows are adjacent and interlock or nest in a manner now to be
explained.
In order to exploit all the advantages of the invention all the
rows must parallel and the beads must be equally spaced along the
axis or the row as shown by the center distance X in FIG. 3. In the
preferred embodiment where the protuberances are symmetrical in
cross section, the transaxial distance between rows should be the
same distance X as shown in FIG. 4. Assuming a datum position for
the box 1 as being stacked in vertical alignment as shown in FIG.
5, then the upward-facing row groups 10 will be axially and
transaxially offset one-half the center distance X (FIG. 3) from
the beads of the downward-facing row groups 14 to be interposed
between and in contact with them. The complete interlocking of the
thus mating row groups is shown in partial section in FIG. 6 taken
through the line 6--6 of FIG. 3. The dimension X may be chosen
according to a number of factors which are apparent to those
comprehending the invention. It is preferable that the beads be so
spaced that contact be accomplished without bottoming that is,
contacting the planar surface from which the opposing protuberances
extend.
In order to effect the interposition of protuberances it is
necessary as a minimum that one of the mating row groups have one
row and that the other have two rows; or in other words, that one
row group have at least one row and the other row group have at
least one more row. As can be seen the interlocking effect will not
resist vertical separation of stacked boxes but will resist
horizontal movement. The relative resistance to dislodgement can be
varied according to the number of rows in each mating row group,
the ultimate number of interposed protuberances determining the
total contact area and thereby the total force resisting rows
dislodgement. The shape of the protuberances is also significant in
effecting more or less strength in the stack. For example, the
truncated cones 16 shown in FIGS. 7 and 8 would be more resistive
than the beads shown in FIGS. 3 and 4. However, one of the
essential advantages of the invention is that the protuberances be
not easily deformed or broken and that they be of sufficient number
to distribute the weight of the box evenly especially when they are
not stacked and more importantly as to the bottom box in the stack.
Thus they should not protrude excessively for it is in their number
that the versatility, stacking strength, and other features of the
invention are achieved rather than in their individual ability to
resist horizontal movement. This advantage is best achieved when
the extension or height of the protuberance is equal to or less
than its cross distance or width at the place of joinder to the
box.
It would also be possible to provide protuberances within the scope
of the invention that would resist vertical dislodgement as well by
shaping them for interference fit as by a terminal enlargement.
The bead or semispherical form 12 shown herein is particularly
advantageous as the interposed beads show good interlocking and
resistance to damage when the bead is hemispherical or less in its
protrusion from the box.
This form is especially useful in boxes of foamed agglutinated
polystyrene granules (commonly called beads, but not so here to
avoid confusion) having been found to be superior to other forms in
daily commercial use. The strength of a polystyrene body (of a
given density) is most effected by the agglutination of the
granules, for it is along the granule boundaries that failure
usually occurs. Failure through fracture of the granules is
considered to indicate the maximum achievable strength. Normally in
production products, failure is at granule boundaries. It would
seem then that for maximum strength the beads 12 should be formed
of as few granules as possible which would also extend into the
box. Thus the protuberance would have less area of granule
boundaries and be less susceptible to damage. It has been found to
the contrary, however, that such relatively large granules do not
work well. They tend to bridge and fail to fill the mold cavity
constituting the protuberance. In addition, it has been found that
beads formed from a plurality of smaller granules have higher
compressive strength and are stronger and more resistant to
deformation or splitting at granule boundaries than a few larger
granules as long as there is no easy starting point for granule
boundary separation. Thus the semispherical bead 12 shown in FIG. 3
with at least about five and preferably about 6-8 polystyrene
granules 18 across its width is exceptionally resistant to damage
and may be conveniently molded while providing good stacking
effectiveness. The truncated cones 16 of FigS. 7 and 8 are not as
desirable because the sharp corner is an easy starting point for
granule separation. Having described the form of the protuberances
and their general and preferred function in stacking there will now
be described some of the special capabilities available with the
invention. FIG. 5 shows a stack in vertical alignment with maximum
interlocking of the matrices. It is noted that the interlocking
shown in FIGS. 5 and 9 is partially schematic since in practice,
one row is partially hidden as in FIGS. 3 and 4. The boxes 1 can be
staggered along the row in increments equal to the center distance
X so as to form a staggered spaced formation such as in FIG. 9. The
formation need not be spaced but may be solid as shown
schematically in FIG. 10 where rectangular boxes having long sides
20 and short sides 22 and row groups as in FIG. 1 are stacked
according to the pattern shown in FIG, 11 where the pattern is
reversed in alternate levels. The overlap of row groups is shown by
the dotted lines indicating a subsequent level where interlocking
of protuberances takes place as shown in part in the shaded areas
24.
Ventilation and environmental control are available even with a
solid formation by choosing an appropriate size and number of row
groups so that there is some space between the interlocked
protuberances. At a minimum the channel is the height of the
protuberance. More effective ventilation and environmental control
is possible by providing the open channels between row groups as
described and shown herein, the pads 6 and 8 providing an increased
spacing. By adoption of a staggered formation even greater
ventilation is possible.
In a commercial application of this preferred embodiment
polystyrene box is used for transporting frozen fish. The box is
approximately 16.times. 12inches and has first row groups of two
rows on its upper surface; one row group along each of the long
sides and one down the center. These row groups are interrupted by
a channel across the width at the center to essentially form the
six row groups 10 shown in FIG. 1. Second similar row groups 14 are
formed on the bottom surface, each having three rows. The beads are
seven-sixteenths inch at their greatest diameter, are spaced
one-half inch on center, and have a height of about one-eighth
inch. The beads tend to become somewhat flattened in use which does
not interfere with their nesting function and is in fact
advantageous for overcoming irregularities when placing the box on
a planar surface. The six first row groups 10 have 13 beads per row
and six second row groups 14 have 14 beads per row. Another
application of staggered formation is the ability to tightly pack
fixed-size transports, such as trucks and trains by merely stacking
the boxes at appropriate spacing to tightly pack the space. It is
noted that if the center distance between rows of a row group is
the same as that along the row axis, then it is possible to use the
compound formation of FIGS. 10 and 11 where boxes are turned at
right angles.
Rigid stacking of nonsymmetrical bodies can be achieved if mating
surfaces are available such as in the embodiment shown in FIG, 12.
All that is required is that each surface be capable of
adjacentwise coincidence with at least one other surface.
The box 26 has on one side a flat surface 28 and on the other side
two surfaces 30 and 32. When stacked, the flat surfaces 28 mate and
the surfaces 30 and 32 mate by alternately inverting the boxes.
Four row groups 34-40 are provided. It is possible in any case
where a flat surface such as 28 is found to stagger and
interconnect stacks, although this can be done only to a limited
extent with the unsymmetrical surfaces 30 and 32 because the boxes
cannot be stacked cross wise in the later case. So many variations
are possible within the broad scope of the invention that further
explication is unnecessary.
* * * * *