U.S. patent number 3,610,172 [Application Number 04/852,028] was granted by the patent office on 1971-10-05 for pallet construction.
This patent grant is currently assigned to Menasha Corporation. Invention is credited to Thomas P. Wharton.
United States Patent |
3,610,172 |
Wharton |
October 5, 1971 |
PALLET CONSTRUCTION
Abstract
The pallet construction comprises a single platform supported on
spaced molded plastic pallet feet mechanically secured to the
platform. Each pallet foot consists of two separate components
adapted for packing and shipping comprising: (1) a circular tapered
cup portion having a flange extending outside of the cup; and (2)
an open circular locking ring consisting of a flange of the same
size as that on the cup with a downwardly depending body portion
rim which extends into the cup and which has a locking means
cooperating with the locking means inside the cup. A variation
utilizes means for attaching a second board or runner to the bottom
of the pallet feet by having holes in the bottom of the feet with
matching holes in the bottom board or runner, and using retaining
fasteners therethrough.
Inventors: |
Wharton; Thomas P. (Neenah,
WI) |
Assignee: |
Menasha Corporation (Neenah,
WI)
|
Family
ID: |
25312332 |
Appl.
No.: |
04/852,028 |
Filed: |
August 21, 1969 |
Current U.S.
Class: |
108/21; 108/56.3;
108/53.3 |
Current CPC
Class: |
B65D
19/40 (20130101); B65D 19/0028 (20130101); B65D
19/0024 (20130101); B65D 2519/00562 (20130101); B65D
2519/00288 (20130101); B65D 2519/00069 (20130101); B65D
2519/00373 (20130101); B65D 2519/00318 (20130101); B65D
2519/00567 (20130101); B65D 2519/00572 (20130101); B65D
2519/00338 (20130101); B65D 2519/00019 (20130101); B65D
2519/00054 (20130101); B65D 2519/00333 (20130101); B65D
2519/00104 (20130101); B65D 2519/00323 (20130101); B65D
2519/00343 (20130101); B65D 2519/00412 (20130101) |
Current International
Class: |
B65D
19/00 (20060101); B65D 19/38 (20060101); B65D
19/40 (20060101); B65d 019/00 (); B65d
019/38 () |
Field of
Search: |
;108/51-58 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gilliam; Paul R.
Claims
I claim:
1. A nestable molded plastic two-part foot adapted to be removably
attached to a pallet platform of the type having openings for
locating said foot and retaining same at the periphery of said
openings, each said foot comprising in combination.
a. A nestable frustoconical cup having,
1. an open upper mouth and a bottom wall connected by a conical
wall extending therebetween, said open mouth and said bottom wall
being disposed in spaced apart planes orthogonal to the
longitudinal conical axis of the cup, said open mouth being of
greater diameter than the diameter of said bottom wall,
2. a flange extending radially outwardly from the substantially
coplanar with said cup open upper mouth, said flange being of a
width sufficient to underlie a portion of a pallet platform
immediately adjacent a foot-receiving opening as aforesaid,
3. a locking shoulder extending radially inward from the inner
surface of said conical wall adjacent to said open upper mouth and
spaced thereaway from for a distance toward said bottom wall, said
locking shoulder having a diameter less than the diameter of said
open upper mouth,
b. a frustoconical locking ring having,
1. a conical wall terminating in upper and lower open mouths, said
mouths being disposed in planes orthogonal to the longitudinal
conical axis of the ring, said upper open mouth being of greater
diameter than the diameter of said lower open mouth,
2. a flange extending radially outwardly from and substantially
coplanar with the upper open mouth of said locking ring, said
flange being of a width sufficient to overlie a portion of a pallet
platform immediately adjacent to a foot receiving opening as
aforesaid,
3. a locking shoulder extending radially outward from the outer
surface of said locking ring conical wall adjacent to said open
lower mouth and spaced therefrom for a distance toward said upper
open mouth, the maximum diameter of said locking ring shoulder
being slightly greater than the minimum diameter of the locking
shoulder of said cup wall, the frustoconical walls of at least one
of said cup and locking ring being radially deformable,
whereby, upon positioning said locking ring and cup into coaxial
alignment with the open lower mouth of said locking ring proximate
to the said open upper mouth of said cup and when said locking ring
and cup are moved axially into engagement, the said locking
shoulders engage and ride past one another by radial deformation of
at least one of said locking shoulders followed by restoration to
normal contour thereof to thereby mechanically interlock said
shoulders, the diameter of the open lower mouth of said locking
ring being dimensioned to lie in the conical surface of the conical
wall of said cup when said cup and locking ring are interlocked as
aforesaid, the said flanges of said locking ring and cup being
thereby disposed in parallel planes and spaced apart a distance not
greater than the thickness of the pallet platform at the periphery
of the foot-receiving openings aforesaid.
2. A nestable molded plastic two-part foot of claim 1 wherein the
bottom wall of the cup is provided with at least one opening, said
opening, said opening being adapted to receive fastening means for
retaining an auxiliary runner on the bottom wall of the cup.
3. A nestable molded plastic two-part foot of claim 1 wherein the
lower face of the flange of the locking ring and the upper face of
the flange of the cup are provided with protrusion adapted to
grip-contacting portions of a pallet platform immediately adjacent
a foot-locating opening
4. A nestable molded plastic two-part foot of claim 1 wherein the
outer surface of the conical wall of the locking ring is provided
with a stop shoulder positioned at a predetermined distance from
the said locking shoulder toward the upper open mouth of the
locking ring, said stop shoulder being adapted to abut the upper
face of the cup flange and to position the flange of the locking
ring at a predetermined distance thereabove not greater than the
thickness of the pallet platform at the periphery of the foot
locating opening aforesaid.
Description
SUMMARY OF THE INVENTION
This invention relates to a pallet construction comprising a
platform of corrugated fiberboard or other suitable board material
such as solid fiberboard, plywood, or other sheet material with
some degree of rigidity, supported on spaced molded plastic feet
secured to the platform. The individual pallet feet are preferably
formed of a separate molded plastic cup portion and a separate
molded plastic locking ring which interlocks with the cup portion
and retains the pallet foot on the platform. According to this
invention several modified foot constructions may be used to
support the platform. Also the assembled pallet construction may be
modified by providing bottom runner strips or a second bottom
runner platform attached to the bottom of the pallet feet to
facilitate moving the pallet on a roller conveyor.
ILLUSTRATIVE EMBODIMENTS
Details of illustrative embodiments of the invention are described
in the following specification and accompanying drawings,
wherein,
FIG. 1 is a perspective view of an assembled pallet made of
corrugated fiberboard platform having die-cut holes in which
individual pallet feet are retained;
FIG. 1A is a fragmental perspective view of a pallet foot in
disassembled relation showing the cup portion positioned adjacent a
die-cut at the lower face of a corrugated fiberboard pallet
platform and the locking ring positioned above the upper surface of
the platform before being inserted and locked in the mouth of the
cup portion;
FIG. 2 is a plan view of the upper face of the locking ring;
FIG. 3 is a plan view of the cup portion of the pallet foot viewed
from the mouth portion;
FIG. 4 is a vertical sectional view of the locking ring taken on
line 4--4 of FIG. 2;
FIG. 5 is a vertical sectional view of the cup portion taken on
line 5--5 of FIG. 3;
FIG. 6 is an enlarged fragmental vertical sectional view taken on
line 6--6 of FIG. 1;
FIG. 7 is an enlarged fragmental vertical sectional view of a
modified construction of the pallet foot;
FIG. 8 is a perspective view of a modified pallet assembly provided
with spaced bottom runner strips retained on the spaced pallet
feet;
FIG. 9 is a perspective view of another modified pallet assembly
provided with a second bottom runner platform retained on spaced
pallet feet;
FIG. 10 is an enlarged vertical sectional view taken on line 10--10
of FIG. 8;
FIG. 11 is a fragmental perspective view in disassembled relation
showing the pallet construction shown in FIG. 10;
FIRST EMBODIMENT
Referring to the drawings, FIG. 1 illustrates a pallet consisting
of a platform 7 made of corrugated fiberboard of suitable
dimension, for example 40.times. 48 inches, which is provided with
nine spaced circular die-cut holes each of which receives a plastic
molded locking ring 11, shown in greater detail in FIGS. 1A, 2 and
4 which is inserted and locked in the mouth of a mating cup 10
positioned at the lower face of the platform 7 and axially aligned
with the die-cut circular holes. The detailed construction of the
cup portion of the foot is shown in FIGS. 3, 5 and 6. The
interlocked relation of the locking ring 11 and cup portion 10 is
shown in FIG. 6. It will be seen that the free cut edges of the
circular die-cut holes 7a are frictionally retained and slightly
compressed between the flange portion 20 of the locking ring 11 and
flange portion 12 of the cup portion 10. The cup portion 10 is
preferably formed of a suitable molded thermoplastic or
thermosetting material, for example high-impact polystyrene,
polypropylene or high density linear polyethylene, which are
inherently rigid but which have some degree of elasticity to permit
mechanically engaged interlocking of the complemental locking
elements provided in the locking ring and cup portion. As shown in
FIGS. 5 and 6, the generally frustoconically shaped cup portion
comprises downwardly tapered wall portions 18 and 19, and a bottom
1 having internal integral radially extending reinforcing ribs 2.
The bottom is also provided with holes 6 to permit drainage in
event water should accidentally collect in cup portion, and also if
desired to permit insertion of attachment means for attaching
bottom runners as will be described hereinafter in connection with
FIGS. 8 to 11. The holes 6 also serve to relieve suction when the
plastic cup portion is ejected from a forming mold. The depressed
central portion in the bottom of the cup portion, shown in FIG. 5,
serves to recess the tail or nib of plastic material which often
remains at the point where the plastic material is injected into
the mold; otherwise this nib would project down past the bottom
surface of the cup portion.
The exterior surface of the bottom 1 of the cup portion 10 is
provided with spaced continuous slightly projecting annular beads
or protrusions 3, 4 and 5, shown in FIGS. 5 and 6, which serve as
bearing areas when the pallet is supported on a supporting surface
and they also serve to reduce slipperiness of the bottom surface of
the cup when the assembled pallet is in use.
The interior upper portion of the body portion 18 is provided with
an inwardly extending locking shoulder portion 16, shown in FIGS. 5
and 6, which terminates in upper rounded edge portion 15 of the cup
flange and lower rounded locking nose portion 17. The upper body
portion of the cup is provided with an integral outwardly extending
annular flange 12 which is provided on its upper surface with
spaced continuous annular beaded portions 13 and 14 which serve to
compressively engage contacting portions of the platform 7, as
shown in FIG. 6, adjacent the die-cut holes 7a. The annular beads
may be replaced by suitable protrusions, or roughened areas, to
increase frictional engagement.
Referring to FIG. 4, the open circular locking ring 11 comprises a
downwardly tapered body portion 31 which has a smooth continuous
interior surface terminating in a downwardly extending portion 30.
Portion 30 slopes at the same angle as the cup wall and is colinear
with it to permit stacking of cups assembled into pallets. The
exterior surface of the body portion of the ring is provided with a
continuous circular channel or locking groove 27 which terminates
in an upper shoulder 26 and a lower locking nose portion 28. The
lower free end portion 29 of the tapered body portion of the
locking ring may be slightly thickened for imparting strength. The
tapered body portion 31 of the locking ring 11 is provided with an
integral flange extending outwardly at the top of the body portion.
The upper surface of the flange 20 is flat and the lower surface is
provided with spaced continuous annular protrusions or beads 21 and
22 which provide gripping means for compressively engaging contact
portions of the platform 7 adjacent the die-cut holes 7a, as shown
in FIG 6, adjacent to the die-cut holes 7a. The annular beads may
be replaced by suitable protrusions, or roughened areas, to
increase frictional engagement.
As stated previously, the pallet platform 7 which is preferably
made of corrugated fiberboard is provided with a plurality of
suitable spaced die-cut circular holes at which the supporting feet
are positioned as shown in FIG. 1. The die-cut holes are of a
predetermined diameter and congruent with the outer diameter of the
body portion 31 of the locking ring 11 so as to permit insertion of
the body portion 31 of the locking ring 11 through the upper
surface of platform as shown in FIGS. 1 and 6. The flange portions
20 of the locking rings 11 are adapted to rest upon and engage the
upper surface portions of the platform 7 adjacent the holes 7a, as
shown in FIG. 6. The flange portions 12 of the cup component 10 is
positioned to bear upon the lower surface portions of the platform
7 adjacent to holes 7a in axial alignment with the locking ring 11.
In assembling the cup 10 and ring 11, suitable pressure is applied
downwardly on the locking ring 11 so as to engage the locking
shoulder 16 of the cup portion within the locking groove or channel
27 of the locking ring. Since the cup and the locking ring are
circular no specific alignment is required, permitting assembly to
be performed easily and, if desires, with a simple machine; and
furthermore no twisting or threading operation is required to
perform the assembly. The dimensions of the channel 27 and shoulder
16 are predetermined so that they can be mechanically interlocked
in the relation shown in FIG. 6. In this position the locking nose
portion 28 of the locking ring 11 engages the locking nose portion
17 of the cup 10, and the shoulder 26 (see FIG. 4) of ring 11 abuts
the edge portion 15 of the cup flange 12 and thus serves as a stop
portion to limit the downward movement of the ring within the cup
10. At the same time the areas of the platform 7 adjacent the
die-cut holes are slightly compressed between the flange portion 20
of the locking ring and the flange portion 12 of the cup portion
which are both of the same width. The annular beads 13, 14, 21 and
22 of the respective flanges also serve to mechanically engage the
areas of the platform adjacent the die-cut holes. The locking means
is designed so that the locking ring 11 cannot be readily
disengaged from the cup portions either accidentally or manually,
since the pallet is expendable and is not intended to be
disassembled for reuse.
A specific exemplary embodiment of the plastic pallet foot
described may consist of a molded plastic cup portion of 0.055
thickness, body height 25/8 inches, top flange diameter 5 1/2
inches, width of locking shoulder one-fourth inch, flange width
one-half inch, and bottom diameter 31/4 inches. The molded plastic
locking ring has a top flange diameter 51/2 inches, flange width
one-half inch, body height three-fourth inch, width of locking
groove one-fourth inch, and open bottom diameter 4 inches. The
circular die-cut holes in the platform have a diameter 41/2 inches.
These dimensions are given by way of example and are not intended
to be in limitation of the invention.
The configuration of the pallet foot is predetermined so that the
cup portion can be nested for packing and shipping; the locking
ring can also be nested for packing and shipping; and the assembled
cup and locking ring attached to the pallet platform permits
nesting of completely assembled pallets.
ADVANTAGES OF THE INVENTION
Pallets made wholly of wood, plywood, metal or plastic are
relatively heavy and expensive and usually must be returned for
reuse at considerable expense rather than being discarded. They
often have the disadvantage that the fork of a fork lift truck can
enter the pallet only in one direction, and they are not nestable.
Pallets made completely of corrugated fiberboard are usually not
strong, their pallet feet are not moisture resistance, and the
labor to assemble such pallets is time consuming and expensive. The
present invention utilizes the inexpensiveness of fiberboard and
the strength of plastics so that pallets of this invention can be
considered expendable. The assembled pallet of the present
invention as well as the components of the pallet feet are nestable
as explained previously. When the savings in shipping and storage
space of empty pallets, in shipping cost due to the light weight
and nestability, and in fabrication and assembly labor costs of the
present pallet construction are taken into account, the economics
are very impressive. Furthermore, the light weight and nestability
of the present pallet permits more pallets to be available at the
point of use and permits empty pallets to be handled by female
labor. The separate components of the pallet construction can be
easily and quickly assembled without special tools, either by the
manufacturer or at the point of use.
The apparent advantages of this pallet construction are thus low
cost, light weight, nestability, and adaptability to any size and
shape of platform required by the user, and any number and location
of pallet feet that may be desired by the user.
A family of pallet feet and locking rings can be provided to permit
a selection of desired feet heights and platform thicknesses. For
example, the illustrative cup is 25/8 inches high; others can be
made of different heights but using the same locking ring. To
accommodate pallet platforms of different thicknesses, several
styles of locking rings can be made differing only in the dimension
from its flange 20 to its locking groove 27.
The family of plastic cups of different heights and locking rings
can be interchangeable by standardizing the size of the die-cut
holes in the pallet platform. The sizes and strengths of the pallet
platforms can be varied to suit the particular loads to be
supported thereon. Thus, according to the present invention it is
possible to select suitable assemblies of the plastic cup, locking
ring and platform for particular needs.
SECOND EMBODIMENT
As previously stated, the construction of the pallet feet and
pallet assembly may be varied. One modification is illustrated in
FIG. 7 wherein the molded plastic cup 65 is provided with an
interior recessed annular groove or channel 67 adjacent the open
mouth of the cup which extends a short distance below the mouth.
The downwardly tapered cup 65 has an integral flange 66 extending
outwardly adjacent the mouth. The open molded locking ring 60
comprises a downwardly tapered body portion 63 which has an
integral flange 61 extending outwardly at the top mouth portion.
The lower end of the body portion is reduced in thickness to
provide an annular flange portion 68 of suitable dimensions to be
telescopically received in groove 67 of the cup and thus form a lap
joint. The contacting areas of the lap joint may be bonded together
with plastic cement or an autogenous seal may be produced by
thermowelding same with high frequency or dielectric heat.
OTHER EMBODIMENT
Modified pallet constructions are illustrated in FIGS. 8 to 11,
wherein bottom runner strips or bottom runner platforms are
attached to the pallet construction shown in FIG. 1. The runners
may be spaced strips 8 of corrugated fiberboard, solid fiberboard,
or other suitable board material, as shown in FIG. 8; or a single
bottom platform 4 of spaced corrugated fiberboard or suitable board
material, coextensive with the upper platform 7 as shown in FIG. 9.
The runner strips 8 are of a length of about the width of the upper
platform 7. The bottom runners are provided die-cut holes 33 for
receiving therethrough fastening means comprising spaced
frustoconically shaped fastener heads 32 carried on supports 31
extending from the fastener base 30. The fastener heads 32 are
adapted to be inserted through holes 6 in the bottom of the cup
portion 10. The fastener heads 32 are preferably made of suitable
soft flexible plastic or other elastomeric material so that they
may be pushed through the holes 6 of the cup 10 and then can expand
inside the cup into locking engagement with the bottom of the cup.
As shown in FIG. 10, the slightly projecting base of the heads 32
frictionally engages the marginal portions of the bottom of the cup
adjacent the holes 6. The construction and method of use of the
different pallet constructions will be apparent from the foregoing
detailed descriptions. Although I have shown and described several
illustrative embodiments of my invention, changes may be made
without departing from the scope of the invention as defined in the
following claims.
* * * * *