BACKGROUND
A pallet for use with the harvesting, processing and/or transportation of food products should be easy to clean and inspect for contamination as it moves through the supply chain. Plastic pallets in general are a better choice than traditional wood pallets in a food application because they do not absorb moisture and can be easily cleaned and sanitized. Automated cleaning lines are now common which can clean pallets efficiently with a combination of hot water, mild detergents and sanitizers. However, the high pressure wash solution must be able to get to and drain away from all surfaces sufficiently. The challenge is to make such a pallet easily cleanable but still maintain all the handling, durability and weight benefits of traditional plastic pallets.
Welding decks and/or adding reinforcement are the most common ways to get a polyolefin pallet to perform similar to wood. However, welding decks can create pockets and ledges that make efficient cleaning difficult. Reinforcement rods can also create traps for dirt and moisture to accumulate.
SUMMARY
The pallet assembly disclosed herein combines a low cost and durable polyethylene with reinforcements in a way that is easily cleanable and still performs similar to wood in stiffness. All surfaces are easily accessed so that one can see if the pallet is clean or contaminated.
Instead of trapping the reinforcement members between the top deck and the columns (or between the top deck and bottom deck/runners) like is commonly done in other pallets, the reinforcement members are trapped entirely in one of the decks. This protects the reinforcement members from damage due to contact with steel fork trucks and pallet jacks during normal use. The reinforcement members are inserted through the sides of the deck in a sequence that traps the internal reinforcement members first, then the perimeter reinforcement members are inserted to complete the assembly. A series of over/under ribs creates the internal structure to allow the insertion of the reinforcement members and to support them in use as well as result in a simple and easy to clean structure.
Traditional reinforcement shapes would ideally be I-beams or rectangular tubes to optimize the strength to weight ratio of the reinforcement member. However, in the example pallet assembly disclosed herein ledges or large flat surfaces running horizontally are minimized by choosing the cross-section to be a round tube. Since these tubes are hollow they will be capped on each end to prevent contamination getting inside. A round tube, while not structurally ideal for load bearing in a pallet (an I-beam is structurally an ideal shape for vertical load bearing in a pallet), is ideal for allowing contaminants to flow off and around as well as cleaning solutions. Of course, ellipses or other irregular cross-sections without horizontal ledges or horizontal flat surfaces could also be used. “Round” is used in this very general sense, including but not limited to annular (cylindrical) or elliptical.
The most preferred material for the reinforcement members in a high end food application is stainless steel due to the material's combination of corrosion resistance, strength and ability to sanitize. However, other materials such as coated steel, aluminum, plastic and various composites may be appropriate in less demanding applications.
The structure of both decks is very open top to bottom with only mild (narrow) T-ribs on the top deck to provide extra surface area to support the loads. Even the bases of the T-ribs are sloped and radiused to promote water drainage. The bottom deck (runners) has a little more surface area on top for strength/durability and to resist damage from forks and pallet jack wheels. All pockets created by the ribs and walls will drain when upright and upside down to promote good cleaning. In assembly all sides of the reinforcement members are visible and accessible through the decks for cleaning. Only where the ribs hold the reinforcement tightly is there contact. Because the reinforcement channels create large openings in both directions it is envisioned that these openings will be closed off for a light duty non-reinforced version or a plastic tube can be used to fill the gap.
The top and bottom deck are joined together at the columns by a weld joint on a single plane. This joint is accessible from the top or bottom so that it can be cleaned. Typically a hotplate weld joint will create a small ledge on each side in a sort of mushroom shape as the weld material is pushed away from the joint due to heat and pressure. This is the weld bead. The exterior bead can be removed mechanically after welding for a more sanitary and finished look. The inside bead is accessible for cleaning. A snap fit joint could also be used for this assembly but the overlapping features needed to make this joint strong would introduce areas that are not easy to clean so a weld is preferred (although not exclusively).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a pallet assembly according to one example embodiment.
FIG. 2 is an exploded view of the pallet assembly of FIG. 1 without the reinforcement members.
FIG. 3 is a side view of the pallet assembly of FIG. 1.
FIG. 4 is a perspective view of the pallet assembly of FIG. 1, partially broken away, with reinforcement members within the channels.
FIGS. 5-10 show a sequence for inserting the reinforcement members into the upper deck of the pallet assembly of FIG. 1.
FIG. 11 is an exploded view of the pallet assembly of FIG. 1 with the reinforcement members in a “width-racking” configuration.
FIG. 12 is an exploded view of the pallet assembly of FIG. 1 with the reinforcement members in a “length-racking” configuration.
FIG. 13 is an exploded view of the upper deck of the pallet assembly of FIG. 1 and a reinforcement member in a first step of being inserted in a width-racking configuration.
FIG. 14 is an end view of the upper deck and reinforcement member of FIG. 13.
FIGS. 15 and 16 show a second step in assembling pallet assembly in the width-racking configuration.
FIGS. 17 and 18 show a third step in assembling pallet assembly in the width-racking configuration.
FIGS. 19 and 20 show a fourth step in assembling pallet assembly in the width-racking configuration.
FIGS. 21 and 22 show the fifth step in assembling the pallet assembly in the width-racking configuration.
FIGS. 23 and 24 show the pallet assembly in the width-racking configuration.
FIGS. 25 and 26 show a first step in assembling pallet assembly in the length-racking configuration.
FIGS. 27 and 28 show a second step in assembling pallet assembly in the length-racking configuration.
FIGS. 29 and 30 show a third step in assembling pallet assembly in the length-racking configuration.
FIGS. 31 and 32 show a fourth step in assembling pallet assembly in the length-racking configuration.
FIGS. 33 and 34 show the fifth step in assembling the pallet assembly in the length-racking configuration.
FIGS. 35 and 36 show the pallet assembly in the length-racking configuration.
FIG. 37 is a side view of the pallet assembly assembled without reinforcement members.
FIG. 38 is a top view of the pallet assembly of FIG. 37.
FIG. 39 is a bottom view of the pallet assembly of FIG. 37.
DETAILED DESCRIPTION
A pallet assembly 10 according to one embodiment is shown in FIG. 1. The pallet assembly 10 includes an upper portion 12 and a lower portion 14 joined together. The upper portion 12 includes an upper deck 16 integrally molded with a plurality of upper column portions 18 extending downward from the upper deck 16. The upper deck 16 is formed primarily of a plurality of intersecting vertically-oriented ribs 20.
The lower portion 14 includes a plurality of lower column portions 22 extending upward from a plurality of runners 26 connecting lower ends of the lower column portions 22 and integrally molded therewith. When assembled as shown in FIG. 1, the lower portion 14 is joined to the upper portion 12 by joining the lower column portions 22 to the upper column portions 18, such as by hot plate welding (alternatively by snap-fit connections or adhesive, but preferably by hot plate welding). The joined upper column portions 18 and lower column portions 22 form columns 24. The runners 26 together could be considered a “lower deck.”
The upper portion 12 further includes a plurality of channels 28 formed therethrough, generally parallel to the upper support surface of the deck 16, one along each peripheral edge and two intersecting perpendicularly through the center of the deck 16. The channels 28 lead into the deck 16 through openings in the upper column portions 18, two in each of the corner upper column portions 18 and one through each of the non-corner peripheral upper column portions 18. In FIG. 1, reinforcement members 32 are disposed in the channels 28 and will be explained in more detail later below.
FIG. 2 is an exploded view of the pallet assembly 10 of FIG. 1 (without the reinforcement members 32). The pallet assembly 10 includes the upper portion 12 and the lower portion 14. The lower column portions 22 each include a pair of perpendicular vertical column ribs 30, each of which is generally parallel to one of the runners 26. The column ribs 30 have upper edges that are higher than the peripheral walls of the lower column portions 22. FIG. 3 is a side view of the pallet assembly 10 of FIG. 1.
FIG. 4 is a perspective view of the pallet assembly 10, partially broken away, with reinforcement members 32 within the channels 28. As shown, the ribs 20 forming the upper deck 16 include first ribs 20a and second ribs 20b. The first ribs 20a extend above and on either side of the reinforcement members 32, but are open below the reinforcement members 32. The first ribs 20a include upper horizontal flanges 36 at upper edges thereof. Where the first ribs 20a intersect one of the channels 28, the first ribs 20a define openings 34 that open downwardly. The first ribs 20a abut the upper half of the circumference of the reinforcement member 32 and then extend straight down to open downwardly.
The second ribs 20b include upper horizontal flanges 38 at upper edges thereof. The second ribs 20b extend below and on either side of the reinforcement members 32, but are open above the reinforcement members 32. Where the second ribs 20b intersect one of the channels 28, the second ribs 20b define openings 40 that opening upwardly. The second ribs 20b abut the lower half of the circumference of the reinforcement member 32 and then extend straight upward to open upwardly.
The channel 28 also extends through an opening 29 through an outer wall 19 of the upper column portion 18. The outer wall 19 of the upper column portion 18 completely circumscribes the opening 29, although this is not essential. The outer wall 19 of the upper column portion 18 extends downward below the uppermost edges of the column ribs 30.
Away from the columns 24, the first ribs 20a alternate with the second ribs 20b. Within the columns 24, there are only first ribs 20a. Within the columns 24, the first ribs 20a are offset from the column ribs 30 that are parallel to the first ribs 20a. Within the columns 24, the openings 34 of the first ribs 20a align with the column ribs 30 that are perpendicular to the first ribs 20a. As shown, the column ribs 30 are aligned with the reinforcement members 32 and abut the reinforcement members 32.
The reinforcement members 32 are preferably a hollow cylinder with end caps 33 secured to ends of the reinforcement members 32 to seal the interiors thereof. The end caps 33 may be secured by adhesive, threads, snap-fit, interference fit, or similar methods. Again, traditional reinforcement member cross-sections would ideally be I-beams or rectangular tubes to optimize the strength to weight ratio. However, in this design, in order to minimize ledges or large flat surfaces running horizontally, a hollow cylinder (or a round tube) is provided. A hollow cylinder, while not structurally ideal for load bearing in a pallet, is ideal for allowing contaminants and cleaning solutions to flow off and around. The first ribs 20a and second ribs 20b, being open downwardly and upwardly, provide access to the reinforcement members 32 and provide good drainage around the reinforcement members 32.
FIGS. 5 and 6 show a reinforcement member 32 being inserted through one channel 28 in a corner column upper portion 18. Referring to FIGS. 7 and 8, another reinforcement member 32 is then inserted past the first reinforcement member 32 through the other, perpendicular channel 28 in the corner column upper portion 18. As shown in FIGS. 9-10, the second-inserted reinforcement member 32 preferably blocks the axial end of the first-inserted reinforcement member 32 within the upper column portion 18.
As shown in FIGS. 11 and 12, using the method described above with respect to FIGS. 5-10, the pallet assembly 10 can be configured with reinforcement members 32 in two ways. Note that with respect to the interior (non-periphery) reinforcement members 32, in one dimension, there will be a single continuous reinforcement member 32 and in the other dimension there will be two shorter discontinuous reinforcement members 32 interrupted by the continuous reinforcement member 32. Since the single, continuous reinforcement member 32 provides more reinforcement, that reinforcement member 32 should be arranged according to the intended racking orientation for the pallet assembly 10.
First, in FIG. 11, a “width-racking” configuration of the pallet assembly 10a is shown. In this configuration, the interior width-extending reinforcement member 32 is a single continuous reinforcement member 32.
In FIG. 12, a “length-racking” configuration of the pallet assembly 10b is shown. In this configuration, the interior length-extending reinforcement member 32 is a single continuous reinforcement member 32.
FIGS. 13 and 14 show a first step in assembling pallet assembly 10a in the width-racking configuration. In the first step, the single continuous interior reinforcement member 32 is inserted into the channel 28 in the middle (non-corner) upper column portion 18 of the side edge of the upper portion 12.
FIGS. 15 and 16 show a second step in assembling pallet assembly 10a in the width-racking configuration. In the second step, the two shorter, non-continuous interior reinforcement members 32 are inserted into the channels 28 in the middle upper column portion 18 of the end edges of the upper portion 12 toward the first reinforcement member 32.
FIGS. 17 and 18 show a third step in assembling pallet assembly 10a in the width-racking configuration. In the third step, two exterior reinforcement members 32 are inserted into the channels 28 in the corner upper column portion 18 of the side edges of the upper portion 12 parallel to the first reinforcement member 32, outward of the two shorter, non-continuous interior reinforcement members 32 of the second step.
FIGS. 19 and 20 show a fourth step in assembling pallet assembly 10a in the width-racking configuration. In the fourth step, two exterior reinforcement members 32 are inserted into the channels 28 in the corner upper column portion 18 of the end edges of the upper portion 12 outward of the first reinforcement member 32, and outward of the two exterior reinforcement members 32 of the third step.
FIGS. 21 and 22 show the fifth step in assembling the pallet assembly 10a in the width-racking configuration. In the fifth step, the upper portion 12 (with the previously-inserted reinforcement members 32) is secured to the lower portion 14, such as by hot-plate welding (or snap-fit connection, etc, although hot-plate welding is preferred).
FIGS. 23 and 24 show the pallet assembly 10a in the width-racking configuration.
FIGS. 25 and 26 show a first step in assembling pallet assembly 10b in the length-racking configuration. In the first step, the single continuous interior reinforcement member 32 is inserted into the channel 28 in the middle upper column portion 18 of the end edge of the upper portion 12.
FIGS. 27 and 28 show a second step in assembling pallet assembly 10b in the length-racking configuration. In the second step, the two shorter, non-continuous interior reinforcement members 32 are inserted into the channels 28 in the middle upper column portion 18 of opposite side edges of the upper portion 12 toward the first reinforcement member 32.
FIGS. 29 and 30 show a third step in assembling pallet assembly 10b in the length-racking configuration. In the third step, two exterior reinforcement members 32 are inserted into the channels 28 in the corner upper column portion 18 of the end edges of the upper portion 12 parallel to the first reinforcement member 32, outward of the two shorter, non-continuous interior reinforcement members 32 of the second step.
FIGS. 31 and 32 show a fourth step in assembling pallet assembly 10b in the length-racking configuration. In the fourth step, two exterior reinforcement members 32 are inserted into the channels 28 in the corner upper column portion 18 of the side edges of the upper portion 12 outward of the first reinforcement member 32, and outward of the two exterior reinforcement members 32 of the third step.
FIGS. 33 and 34 show the fifth step in assembling the pallet assembly 10b in the length-racking configuration. In the fifth step, the upper portion 12 (with the previously-inserted reinforcement members 32) is secured to the lower portion 14, such as by hot-plate welding (or snap-fit connection, etc, although hot-plate welding is preferred).
FIGS. 35 and 36 show the pallet assembly 10b in the length-racking configuration.
Alternatively, the pallet assembly 10 could be assembled and used without reinforcement members 32, as shown in FIGS. 37-39.
In this manner, the same pallet assembly 10 could be assembled and used in any one of the three configurations.
In accordance with the provisions of the patent statutes and jurisprudence, exemplary configurations described above are considered to represent a preferred embodiment of the invention. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
Patent Application
20200231332
