Interlocking pallet for paperboard container with attaching strips

A wood reinforced corrugated paperboard shipping container with interlocking pallet to direct positioning of the container on the pallet and to interlock the container with the pallet. The pallet includes longitudinal runners and cross members. At least one cross member overhangs the side of a lower runner. The overhang portion of the cross member and the side of the runner together define a recess which receives an attaching strip that is connected to a lowermost portion of the wall of the container. In placing the container on the pallet, a beveled upper surface on the overhang portion of the cross member bears against the bottom surface of the attaching strip. The attaching strip thereby moves downwardly and out to move around the outside end of the overhang portion of the cross member and the back into the recess, thereby matingly interlocking the container to the pallet.

TECHNICAL FIELD 
This invention relates generally to pallets for corrugated paperboard 
containers, and, more particularly, to an interlocking pallet and 
corrugated container for packing, shipping and storing articles. 
BACKGROUND OF THE INVENTION 
Packaging heavy, bulky machinery such as lawn and garden tractors, lawn 
mowers, snow mobiles, boat motors, engines, air compressors, air 
conditioners and the like presents many unique considerations. Because 
such machinery is by nature difficult to handle and store, convention 
double-wall or triple-wall laminated corrugated paperboard containers have 
long been recognized as being unsuitable for packing heavy machinery. As a 
result, wood reinforced boxes with mating bases and top frames have been 
developed. These shipping containers are often referred to as wood cleated 
boxes. 
The conventional wood cleated box consists of a wood reinforced corrugated 
paperboard body, a wooden top frame and a wooden base. At least one 
interior wall of the corrugated body is provided with a wood reinforcement 
vertically aligned to provide stacking strength. The corrugated paperboard 
body gives the container definition and maintains the position of the 
vertical wood reinforcements. The base member, often referred to as a skid 
or pallet, supports the container and the product packed therein. The top 
frame closes off the container and provides a constant surface upon which 
another container may be stacked. The top frame aids in distributing a top 
load imposed on the container; for example, a top load is imposed by a 
smaller package placed on top of the container in a less-than-load 
shipment. The arrangement of the wood cleated box seeks to prevent 
collapse of the container even when shipped and stored in multi-unit 
stacks, typically having between two to six units. 
These wood cleated boxes are often handled by clamp trucks and forklifts 
during shipping and storing. To facilitate the use of clamp trucks and 
forklifts with such wood reinforced corrugated paperboard shipping 
containers, U.S. Pat. No. 4,832,256 discloses separate, specifically 
configured attaching strips on the lowermost portion of the corrugated 
body or container. The attaching strips are fixedly secured to the 
container in alignment with the sides of the base. The container is placed 
on the base and joined thereto. Typically, a container properly positioned 
on its base has a lowermost edge in a substantially horizontal plane. 
After the container is positioned on the base, a series of spaced-apart 
nails or staples are driven through the container wall, through the 
attaching strip and into the base to join the container and the base 
together. Such a container resists separation of the corrugated body from 
the base and can be handled by clamp trucks and forklifts. The attaching 
strips reinforce the lower edge of the container where the staples or 
nails are driven to attach the container to the base. The attaching strips 
are made of a material which is denser than the corrugated paperboard. 
This construction resists the staples from pulling through the container 
walls and thereby prevents separation of the container from the base. 
In some instances, however, during packing of heavy equipment on an 
assembly line, the container is not properly positioned on the base. This 
leads to several problems. First, these types of wood cleated boxes are 
typically stacked two to six units high when held in warehouses, during 
shipping, and during handling. Without being fully positioned or seated 
down around the base, the container is not square. One corner or side is 
higher than the other corners or sides. As a result, the stack of wood 
cleated boxes leans and is unstable. A stack of wood cleated boxes which 
falls causes irreparable damage to the container, significant damage to 
the product and potential harm to bystanders. Second, staples or nails are 
used to join the attaching strips on the container to the base. Without 
being properly positioned, the container is not adequately secured to the 
base. Forklift or clamp truck handling of such boxes with a mis-positioned 
container can result in separation of the container from the base, again 
causing damage to the container and the contents, as well as risking 
potential harm to bystanders. Third, the pressure exerted by the weight of 
such stacked containers leads to damage of the box having an improperly 
seated container. For example, such pressure causes the staples used in 
joining the improperly seated container to the base to be bent, deformed, 
or broken, thus allowing the base to separate from the container. 
Furthermore, some assembly lines on which these wood cleated boxes are 
packed use compressed air operated staplers to join the container to the 
base. These staplers, whether automatic or manual, may continue to operate 
even after the supply of staples is exhausted. Usually, the operators of 
such stapling machinery visually check the magazine of the stapler to 
insure that the supply has not been exhausted, but such visual checking 
may be overlooked for several cyclings of the equipment. As a result, the 
container is either not joined or is insufficiently joined to the base. 
This, of course, can also result in separation of the base and the 
container during handling. Such separation leads to damage of the 
container and the contents, as well as potential injury to bystanders. 
A clamp truck handling a box with missing fasteners can also lead to damage 
of the container and contents and injury to persons nearby. Clamp trucks 
supply force to the sides of the container with hydraulically operated 
platens. If the base is not properly fastened to the container, the weight 
of the product can cause the base to fall out during clamp truck handling, 
risking damage to the product and bystanders. 
Thus, there is a need in the prior art for a container and base that 
addresses the problems of joining the container to the base so that the 
container is seated properly on the base and the container is interlocked 
to the base. 
SUMMARY OF THE INVENTION 
The present invention solves the above-described problems with corrugated 
containers and support bases by providing a pallet that helps seat the 
container and that interlocks with the seated container. Generally 
described, the present invention provides a recess that receives an 
engaging member to matingly interlock the container and the pallet. More 
particularly, the present invention provides a pallet with a cross member 
that overhangs the side of a lower runner. The overhang portion of the 
cross member and the side of the runner together define a recess which 
receives an attaching strip that is connected to a wall of a container. 
The container is placed on the pallet to position the attaching strip in 
the recess and thereby matingly interlock the container to the pallet. 
Generally described, the wood cleated box constructed in accordance with 
the present invention comprises a wood reinforced corrugated paperboard 
container and a rigid base that supports the article to be packed. An end 
of a cross member on the base overhangs a side of a runner on the base to 
define a recess. The corrugated paperboard body includes at least one 
attaching strip fixedly secured to a wall. The container and the base 
interlock by placing the container onto the base. The attaching strip 
aligns with the side of the base and slips around the outer edge of the 
end of the cross member into the recess. 
Thus, it is an object of the present invention to provide an improved 
interlocking, wood cleated corrugated paperboard shipping container and 
base. 
It is a further object of the present invention to provide a base which 
helps seat the corrugated paperboard container to the base. 
It is a further object of the present invention to provide a base which 
matingly engages a corrugated paperboard container to form an interlocked 
box and thereby insure against separation of the base and the container. 
It is a further object of the present invention to provide a base that 
interlocks with a container to assure against separation during handling. 
It is a further object of the present invention to provide a base that 
maintains connection to the container to assure against separation in the 
event that a fastening machine malfunctions and fails to rigidly join the 
base and the container. 
These and other objects, features and advantages will become apparent from 
a reading of the following detailed description of the invention and 
claims in view of the appended drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now in more detail to the drawings, in which like numerals 
indicate like parts throughout the several views, FIG. 1 shows a preferred 
embodiment of a base 10 that interlocks with a reinforced corrugated 
paperboard shipping container 12 having attaching strips according to the 
present invention. A top frame 14 is illustrated above the corrugated 
container 12. 
The base 10 is a rigid pallet adapted to hold articles to be packaged, 
stored and shipped in the container 12. In the embodiment illustrated in 
FIG. 1, the base 10 consists of wood floor boards, runners, end pieces, 
and cross members. A plurality of floor boards 20, 22, 24 and 26 are 
parallel and spaced-apart. Each floor board extends the entire width of 
the base 10. Two runners 30 and 32 are disposed substantially 
perpendicular to the floor boards 20-26 and extend the length of the base. 
The runners 30 and 32 are made of wood or other dense material and are 
fastened or otherwise secured to the floor boards 20-26 by nails, staples 
or other suitable fasteners, glue or other suitable means. The end pieces 
33 and 35 are disposed longitudinally on the floor boards 20 and 26, 
respectively, and are fastened in a similar manner to the floor boards. It 
should be noted that the runners 30 and 32 and the end pieces 33 and 35 
are set off from the outside corner of the floor boards 20 and 26. In an 
alternate embodiment, the end piece 33 comprises two spaced-apart blocks 
(best shown in FIG. 3 discussed below). This permits entry of the blades 
of a fork lift truck into the base. However, the thickness of the floor 
boards 20-26 may be sufficient to define an entry space for the blades of 
a fork lift truck. The thickness of fork lift blades is generally between 
11/4 inches and 2 inches. For boxes handled only by clamp truck, the floor 
boards are about 1/2 inch thick. 
The base 10 further consists of at least one center reinforcing runner 36 
that extends the length of the base 10 and is fastened to the floor boards 
20-26, as discussed above, to give stability to the base 10. In an 
alternate embodiment (not illustrated), the base 10 has two spaced-apart 
center runners. This provides added strength to the base for handling. In 
the embodiment having the two end blocks, the pair of center runners 36 
guide the positioning of the blades in the base. 
Secured to an upper surface of the runners 30, 32 and 36 are four 
spaced-apart cross members 40, 42, 44 and 46. The cross members 40-46 
extend between the runners 30 and 32. The cross members 40-46 in the 
illustrated embodiment are parallel and are disposed substantially 
perpendicular to the longitudinal axis of the runners 30 and 32. Each 
cross member 40-46 has a pair of longitudinally spaced distal ends 50. 
With reference to FIG. 2, each of the ends 50 extends as an overhanging 
ledge laterally from an edge defined by an outside face 52 of the 
respective runners 30 and 32. The overhanging ends 50 and the outside 
faces 52 define a plurality of recesses 54 on the sides of the base 10. 
The ends 50 in the illustrated embodiment are beveled on an upper surface 
56 to taper downwardly towards an outside end 58 of each of the cross 
members 40-46. 
The container 12 in the illustrated embodiment is a corrugated paperboard 
body formed by a blank 80 of corrugated paperboard material. The blank 80 
includes four main panels 82, 84, 86 and 88 foldably connected along score 
lines. The four main panels 82, 84, 86 and 88 form the four walls of the 
container 12 as shown in FIG. 1. A manufacturers joint is foldably 
connected to one of the main panels. The function of the joint is well 
known to those skilled in the art and is otherwise outside the scope of 
the present invention. In the illustrated embodiment, a series of four top 
flaps generally designated 90 are foldably connected to the main panels. 
Each main panel 82, 84, 86 and 88 is provided with an attaching strips 92, 
94, 96 and 98, respectively, at its lowermost portion. Each one of the 
attaching strips 92-98 is made of a dense material with sufficient 
strength to prevent or resist nails or staples being pulled through the 
material. Each attaching strip extends substantially the length of its 
respective main panel. The attaching strips 92-98 are fixedly secured to 
the inside surface of the main panels preferably by both staples and 
adhesive. However, any suitable means of attaching is acceptable. 
The main panels 84 and 88 of the blank 80 are each provided with a pair of 
vertical corner reinforcements 100. The vertical reinforcements 100 are 
made of wood or other material of sufficient strength and stiffness to 
support a vertical stacking or top load force. The reinforcements 100 
extend substantially the height of their respective main panels 84 and 88. 
The lowermost edge of the vertical reinforcements 100 sit near the very 
bottom of the respective main panels 84 and 88. The bottom portion of each 
vertical reinforcement 100 is notched as generally indicated at 102. An 
uppermost portion 103 of each corner vertical reinforcement 100 is beveled 
such that the outer portion of the reinforcement is of greater height then 
the inner most portion of the reinforcement. 
The main panels 82 and 86 are each provided with at least one reinforcing 
member 104 which is made of the same materials as the vertical 
reinforcements 100. The reinforcing member 104 extends substantially the 
height of its respective main panel. Each reinforcement 104 extends no 
lower than the attaching strip 92 and 96 and extends no higher than the 
innermost edge of the top surface of the vertical corner reinforcement 
100. 
The top frame 14 in the illustrated embodiment consists of two members 120 
and 122 that run lengthwise of the container 12. Secured to the top of the 
two lengthwise pieces 120 and 122 are three cross pieces 125, 127 and 129. 
These elements 120, 122, 125, 127 and 129 are usually made of wood and may 
be secured in this arrangement by nails, staples, or other suitable 
connectors. The top frame 14 is dimensioned to sit in the uppermost 
portion of the corrugated paperboard body 12. The ends of the lengthwise 
members 120 and 122 are each formed with notches generally designated 130. 
The notches 130 are beveled to facilitate receipt of the top frame 14 on 
the upper portions 103 of the corner reinforcements 100 on the corrugated 
paperboard body 12. 
In the practice of the present invention, the blank 80 of corrugated 
paperboard is laid flat. The attaching strips 92, 94, 96 and 98 are fully 
glued and stapled to the main panels 82, 84, 86 and 88, respectively. A 
preferred adhesive is polyvinyl alcohol (PVA) and any suitable adhesive 
may be used. The preferred staples are 3/4 inch to one inch crown and have 
a leg length equal to approximately the thickness of the attaching strips 
92, 94, 96 and 98 plus a thickness of the blank 80. It is furthermore 
preferred that the staples be spaced-apart a distance of approximately 
four inches and angled at 45.degree. to achieve maximum contact of the 
corrugated paperboard main panels 82, 84, 86 and 88 to its respective 
attaching strip. While it is preferred that the attaching strips 92, 94, 
96 and 98 be located along the bottom edges of the interior of the main 
panels, the attaching strips may be secured to the exterior surfaces of 
the main panels in an alternate embodiment illustrated in FIG. 3. In this 
embodiment, an opening 134 is formed in the paperboard walls 82 and 86 
immediately above the upper surface of the attaching strips 92 and 96. The 
position of the opening 134 in the paperboard wall corresponds to the 
position of the outside end 58 of the cross members 40, 42, 44 and 46 when 
the container 12 is seated on the base 10. In this embodiment, the staples 
joining the container 12 to the base 10 effectively squeeze the corrugated 
board between the attaching strips and the base. This may be of an 
advantage when the weight of the linerboard in the corrugated paperboard 
container is light and does not provide an adequate glue bond surface for 
the attaching strip to be placed on the inside. The openings 134 are sized 
to receive the outside end 58 of the cross members 40-46. The cross 
members are long enough to protrude through the openings 134 so that the 
beveled end portion can overlap the attaching strip 92 and 96 on the 
outside surface of the respective main panel 82 and 86. 
In a similar manner, the vertical corner reinforcements 100 are attached to 
the main panel 84 and 88. The notches 102 in each corner vertical 
reinforcement 100 are aligned with their respective attaching strips 94 
and 98 on the main panels 84 and 88, respectively. Additionally, the 
center reinforcements 104 are glued and stapled to their respective main 
panels 82 and 86. 
Once the corrugated paperboard body 12 is formed, it is placed over the 
base 10. In placing the container 12 over the base 10, a bottom surface of 
the attaching strips 92 and 96 is pushed against the beveled surface 56 of 
the cross members 40, 42, 44 and 46. The main panels 82 and 86 are pushed 
outwardly by the downward bevel to allow the attaching strips 92 and 96 to 
slide around the ends of the cross members 40, 42, 44 and 46 and thereby 
move into the recess 54. The attaching strips 92 and 96 thus sit flush 
against the runners 30 and 32 while the attaching strips 94 and 98 sit 
flush against the end pieces 33 and 35. The notches 102 in the bottom 
portions of the vertical corner reinforcements 100 are positioned such 
that the notched surface sits flush against one of the end pieces 33 and 
35. The bottom of the center reinforcement 104 sits on the upper surface 
of the cross member 42 or 44. As discussed above, the ends 50 of the cross 
members 40-46 are beveled. For the end cross members 40-46, the bevel is 
preferably at a 45.degree. angle to the longitudinal axis of the cross 
member. The bevel preferably begins in the upper surface of the cross 
member at a line defined by the longitudinal axis of the runner below the 
cross member. For the inner cross members 42 and 44, the bevel angle is 
greater than 45.degree. to accommodate a flat area on the upper surface of 
the cross member on which the bottom of the vertical cleat 104 rests. 
It will be appreciated that the thickness of the attaching strips 92, 94, 
96 and 98 must not be greater than half the thickness of the vertical 
corner reinforcements 100. The outermost portion of the attaching strips 
92, 94, 96 and 98 is to be in alignment with the outermost portion of the 
notched surface in the vertical reinforcements 100. When the corrugated 
paperboard body 12 is thus fit about the base 10, the attaching strips may 
be joined by nails or staples to the runners 30 and 32 and the end pieces 
33 and 35 in the notched portion of the vertical corner reinforcements 
100. The top frame 14 is configured to fit inside the upper dimensions of 
the corrugated paperboard body 12. The notches 130 of the lengthwise wood 
pieces 120 and 122 are positioned to fit over the beveled surfaces at the 
top of the corner vertical reinforcements 100. This arrangement serves to 
lock the top frame 14 into the corner vertical reinforcements 100. The 
cross pieces 125, 127 and 129 are appropriately positioned to clear and to 
protect any heavy package machinery. 
It will be appreciated that the above-described invention provides a 
significant advantage over prior art containers. The upper surfaces 56 of 
the cross members direct the positioning of the container 12 on the base 
10. The beveling on the upper surface 56 further facilitates such 
positioning. Each of the attaching strips 92 and 96 is directed around the 
respective ends 58 of the cross members 42, 44, 46 and 48 and into the 
recess 54. In the illustrated embodiment, the main panels 82 and 86 are 
moved outwardly as the lower surface of the attaching strips 92 and 96 
slide on the beveled upper surface 56 of the cross members. As the 
attaching strips move into the recess 54, the main panels 82 and 86 move 
laterally back toward the base 10. The attaching strips 92 and 96 are thus 
held in the recesses 54, thereby interlocking the container 12 to the base 
10. This insures connection of the respective component parts and prevents 
separation of the base 10 from the container 12 under normal conditions of 
packing and handling. Further, in the event that a staple gun misoperates, 
or runs out of staples without notice, the interlock of the pallet to the 
container restricts separation of these component parts during handling, 
packing and shipping of equipment. 
FIGS. 3 and 4 further illustrate alternate embodiments of the base and the 
container. For convenience, the elements identified with a prefix "2" 
correspond to the elements identified above. In an alternate embodiment, 
the container 212 includes a series of seats which are spaced apart in the 
main panels 82 and 86 of the container. Each seat is an opening 134 which 
receives one end 258 of one of the cross members 240-246 when the 
container 212 is placed over the pallet 10. The attaching strips 292-298 
are illustrated on the exterior surface of the main panels, but may be on 
the interior surface. The lower surface of the cross members 240-246 is 
next to the upper surface of the attaching strips 292-296 (not shown). 
In another alternate embodiment for lighter weight items, the container 
includes the seats 134 but does not include the horizontal attaching 
strips 292-298. The container 212 and the base 210 are connected by 
inserting the ends 258 of the cross members 240-246 through the seats 134 
in the main panels 282 and 286. In a preferred embodiment, the base 210 
does not include the floor boards 20-26. Rather, the base 210 consists of 
the runners 230, 232 and 236, the end blocks 233 and 235, and the cross 
members 240-246. As illustrated, the base 210 is strengthened by using a 
pair of cross members 320 which extend between the outside runners 230 and 
232 but do not overhang the outside edge of the runners. In this 
embodiment, the end blocks 233 and 235 extend inwardly perpendicular from 
the longitudinal ends of the outside runners 230 and 232. The end blocks 
are offset slightly from the ends of the runners, and thereby cooperate 
with the ends to define an L-shape notch 302, the purpose of which is 
discussed below. The end blocks 233 are spaced-apart, as are the end 
blocks 235, to define a gap 310 at each end of the base 210 for receiving 
therethrough the blades of a fork lift truck, as discussed above. 
The cross members 240 and 246 each include L-shaped notches 304 at their 
respective longitudinal ends. The notches 302 and 304 cooperate to define 
a socket 306 which receives the tennon portion of the vertical cleat 2100 
of the container 212. As may be appreciated by those of ordinary skill in 
the art, the end panels 284 and 288 of the corrugated container 212 
include a notched portion along the bottom edge corresponding to the gaps 
310 defined by the spaced-apart end blocks 233 and 235. The height D of 
the notch is equal to or slightly greater than the height of the runners 
230, 232 and 236. The length of the attaching strips 294 and 298 match the 
length of the end blocks 233 and 235. The assembly and use of the 
alternate embodiment illustrated in FIGS. 3 and 4 is like that discussed 
above. It should be noted that the tennon of the vertical cleat 2100 is 
received by the respective socket 306 when the container 212 is positioned 
on the base 210. A nail or staple is placed through the tennon into the 
runner 230 (or 232) of the base 210 to further rigidly join the base and 
the container. The bottom of the center reinforcement 2104 sits on the 
upper surface of the cross member 244. 
This specification has thus described various embodiments, including a 
preferred embodiment, of the present invention, and including the steps 
necessary for fabricating such embodiments. It is to be understood, 
however, that numerous changes and variations may be made in the 
construction of the present interlocking container within the spirit of 
the present invention. It should therefore be further understood that 
modifications of the present invention may be made without departing from 
the scope thereof as set forth in the appended claims.