TECHNICAL FIELD
The present disclosure relates to improved, fire sprinkler friendly pallets, which are used with forklifts for transporting goods. These pallets serve as part of a system for storing goods in warehouses and the like, which system also has sprinkler systems for suppressing fires.
BACKGROUND
Pallets, both bearing goods and empty, are often stored on racks in warehouses that are fitted with fire-fighting automatic sprinkler systems. Plastic pallets may present particular challenge for such systems, as compared to traditional wood pallets. Specifically, in the event of a warehouse fire, particularly with regard to a plurality of plastic pallets, the heat and rate of combustion of, for example, a polyethylene or polypropylene pallet material will be inherently high as compared to wood and the like. Existing sprinkler systems designed for traditional wooden pallets may become overwhelmed in the event of a bad conflagration. Adding additional sprinkler systems, or having special areas for plastic pallets, can be done, but involves substantial unwanted costs or logistics problems.
Indeed, plastic pallets have not gained wide acceptance due in large measure to the failure to satisfactorily meet fire resistance criteria and structural and durability standards of Grocery Manufacturers of America (GMA). According to such criteria, pallets should have fire resistance sufficient to not exceed the heat release set by Underwriters Lab Standard 3435. Conforming pallets must pass a simulated warehouse fire test in a test facility, must be strong enough to carry specified loads, must not be too heavy, and must be durable in resisting damage during use, as measured by certain other tests simulating field use.
What is needed is an improved pallet, made from plastic, metal, wood or combinations of the foregoing, having improved fire resistance without compromising strength.
SUMMARY
The above mentioned problems are overcome by the presently disclosed fire sprinkler friendly pallet, which pallet has a corrugated deck including a plurality of holes in the valleys of the corrugations. In an exemplary embodiment, the flow area of the holes is located predominately over the rails of the base of the pallet. In such case, water falling on the pallet falls onto the plastic rails underneath the deck and inhibits burning during a fire.
In exemplary embodiments, connector channels run between the valleys so that water can be more evenly distributed amongst the valleys and thus the rails of the base. In another embodiment, such connector channels are arranged in staggered fashion. In another embodiment, corrugation valleys are pitched along their lengths, so that water runs toward the holes.
In another exemplary embodiment, the frame, which supports the deck, has holes, so that water falling on the frame surface can flow through the frame onto the base parts of the pallet below the holes. In another embodiment, the frame top has a concave gutter shape, so that water flows lengthwise along the frame to the holes.
In another embodiment, the pallet has a base rail with a surface which is sloped or crowned or corrugated and which has holes for water to fall on portions below.
The above-described and other features will be appreciated and understood by those skilled in the art from the following detailed description, drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the accompanying FIGURES, which are meant to be exemplary and not limiting:
FIG. 1 is a semi-schematic elevation view illustrating pallets stored on a rack in a warehouse having sprinklers;
FIG. 2 is a partial vertical cross-sectional view of an exemplary pallet including corrugations having holes;
FIG. 3 is a perspective cutaway view of an exemplary pallet including corrugations having holes;
FIG. 4 is a perspective cutaway view of an exemplary pallet having interconnected corrugations having holes;
FIG. 5 is a perspective cutaway view of an exemplary pallet having corrugations interconnected with an angled deck supporting frame having holes;
FIG. 6 is a partial vertical cross-sectional view of an exemplary pallet having contoured base portions;
FIG. 7 is a partial vertical cross-sectional view of another exemplary pallet having contoured base portions; and
FIG. 8 is a partial vertical cross-sectional view of another exemplary pallet having contoured base portions.
DETAILED DESCRIPTION
Referring now to FIG. 1, a semi-schematic elevation view illustrates pallets stored on a rack in a warehouse having sprinklers. Pallets 20C are illustrated as provided singly, stacked, and loaded with goods 24, wherein the pallets are stored on racks 22 which comprise opposing side columns 22L and 22R and horizontal rails 34 which are spaced apart to receive the opposing edges of the pallets. The ceiling 30 of the warehouse is fitted with a firewater plumbing system comprising pressurized water pipes 28 and sprinkler heads 26. For typical sprinkler heads, when the ceiling temperature rises above a predetermined design point, established by selection of a low melting point metal that restrains a spring-loaded water valve, the sprinkler heads open and discharge a volume of water W in the form of sprays 32. The spray water falls generally downwardly, to land on the stored pallets below. The aim is to cool the burning objects below the point of ignition, and to prevent non-burning objects from rising to such point.
Referring now to FIG. 2, as illustrated by the partial vertical cross section of a pallet 20, the pallet deck 46 of an exemplary pallet 20 is corrugated for strength. Through-holes 40 receive water W within the valleys 45 of corrugations and pass water W to structures 44C below the pallet deck 46, thus cooling those structures below. The edge of a pallet 20 rests on the rail 34 of a rack 22L. It is to be understood that the term corrugation or corrugated should encompass any surface topography that includes at least one channel, groove, depression or valley along which water can be channeled or contained. Additionally, the base of the pallet includes any portions of the pallet below the top surface of the pallet, which top surface may include the deck and the top portions of the frame.
Referring now to FIG. 3, exemplary pallet deck 46, which may comprise metal, metal alloy, plastic or other material, is attached to rectangular plastic frame 48 of pallet 20. The frame 48 is mounted on columns 42, 42C which run down to the base comprising outer rails 44 shaped as a rectangle and cross rails 44C which run to and from the midpoints of rails 44, crossing at center column 42C. Metal beams, not shown, or other reinforcing components may be provided within the rails and frame 48 for strength as in U.S. Pat. No. 6,705,347, the disclosure of which is incorporated herein by reference. As in FIG. 2, the exemplary pallet deck 46 has a multiplicity of corrugations for strength which comprise depressions or valleys 45.
With reference to FIGS. 2 and 3, through-holes 40 are located at the bottom of valleys 45 of the deck. The holes are selectively located over the rails 44C or whatever other structure comprises a lower portion of the pallet. There may be other holes which are not above rails or other bottom structure, for drainage. For instance, if there is a corrugation depression which does not lie above a rail, that corrugation could be fitted with a hole.
Thus, at least part of the water W which lands on the pallet during a fire, either from sprinklers, or from another pallet stacked above, flows through the specially-positioned holes 40, so the water lands on a thermoplastic rails 44C or other structure which comprise the base of the pallet, to suppress or prevent burning. Improved performance has been seen in the aforementioned Underwriter Laboratories tests. Should a pallet have a continuous bottom deck construction, then holes can likewise be placed in the bottom deck. The valleys 45 may be sloped slightly along their length, so water runs downwardly toward the holes 40.
With reference to FIG. 4, another exemplary embodiment is illustrated at 20A. At least some of the corrugations of the deck are connected by connector channels 50, to help distribute the water amongst the different valleys 45. Such configuration tends to even water flow into holes 40, when the water falls unevenly on the surface of the deck. The connectors 50 may also be staggered from valley to valley, for best deck strength.
Referring now to FIG. 5, part of an exemplary corner of a pallet is illustrated. In one exemplary embodiment, frame 48A, which supports deck 46, has through holes 52, which are configured to drop water on the outer rails 44 of the base. In another exemplary embodiment, the top surface of the outer part of the frame is sloped inwardly toward the center at slight angle Z. In such embodiment, water falling on outer portions of said deck supporting frame will tend to run to inner portions of said deck supporting frame. The top surface of the frame may also provide a gutter 60, so water will flow lengthwise along the frame, as suggested by the arrows. Water flows to the locations of holes 52 which are positioned above base rails 44, as they run between the columns. The water drops onto the base rail 44, and from there onto any pallet below. Thus water which lands on, or flows over typical frame surface portion 56, which is over the corner column 42 (not shown in FIG. 5), is usefully directed onto the base or other lower portions of the pallet. In addition, peripheral connector channels 58 may be used to allow water in some of the valleys 45 to flow onto the top of the frame and into the gutter.
In other exemplary embodiments, the top surface of rails 44, 44C may be usefully shaped to help fire resistance. Referring now to FIG. 6, rail 44A is provided with a slope, which directs water towards internal portions of the pallet or ensures that water will flow through lower portions of the pallet to goods or additional pallets below, rather than allowing water to possibly flow outward, as when the rail 44a is flat or fully crowned. Referring now to FIG. 7, exemplary rail 44B has a surface which is concave or grooved, such that water flows through holes 62 provided in lower portions of rail 44B and onto goods or additional pallets below, rather than allowing water to possibly flow outward. Similarly, FIG. 8 illustrates an exemplary rail 44E having a corrugated surface for the similar purpose. Such base portion surface contouring, which contouring selectively directs water, may similarly be applied to base portions provided underneath holes in said deck.
It should be noted that the perforations in the deck and other parts of the pallet need not be round. For example, slots, among other configurations, may be used. At any location, more than one hole may be placed. The holes may also be of various sizes. As should be evident, the different features described can be combined with each other. Pallet materials may comprise plastics, metals, wood, and the like, as well as combinations of the foregoing.
Accordingly, the present disclosure provides a water flow control system for a pallet, which selectively directs water deposited on upper surfaces of a pallet by fire sprinkler systems to lower portions of the pallet that may gain additional fire resistance from exposure to such water.
While exemplary embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. It is to be understood that the present invention has been described by way of illustration and not limitation.
Patent Application
20060236900
