TECHNICAL FIELD

[0001] This application relates to a portable, foldable mat for delivering heavy materials over weak floors, more particularly a portable, foldable mat for construction sites that has a plurality of panels foldable upon one another from a first end toward a second end onto itself repeatedly until any tertiary panels are contained between an initial panel and an immediately neighboring second panel of the initial panel and encapsulating a sheet of high density polyethylene within each panel.

BACKGROUND

[0002] Drywall is delivered to countless large construction sites, such as hotels, apartments, multi-family homes, etc. during construction when the floors are often plywood subfloors. These plywood floors have limited thickness and strength and may have been exposed to the elements such as rain and snow during the construction for days, weeks, or even months, which decreases the strength thereof. Subfloors are typically installed with the long axis perpendicular to three or more supports spaced 24 inches on center. The concentrated static and impact test criteria accepted in the industry require a minimum ultimate load of 400 pounds after an impact test applied with a one inch diameter disc for subfloor-24 panels. Wet conditions require a 25 percent reduction in design bending strength, which means the 400 pounds is reduced to 300 pounds to account for wet conditions.

[0003] A typical sheet of drywall weighs between 55 to 120 pounds, depending upon size and composition. Drywall sheets may be carried by hand to various rooms within the building or may be loaded onto drywall carts, hand trucks, or dollies (up to 2000 pounds) and rolled over the plywood subfloors. A typical drywall cart has 2-inch-wide by 8-inch-diameter wheels which typically provide about 1/2 square inch of effective contact area per wheel. Some of these carts have allowable capacities of over 2,000 pounds, or 500 pounds per wheel (“load rating”) if the load is evenly distributed. This amount of weight concentrated on the wheels of the cart can exceed the design capacity or rating of the subfloor, not just the plywood, but the joist, plywood, etc., and can damage or break through the subfloor.

[0004] Also, depending on the stage of construction, the studs defining doorways may still be present across the floor, i.e., the framers have not cut the stud at the base of the doorway yet. As such, the cart may need to “hop” over a stud. This “hop” can shift and increase the weight distribution on the wheels, thereby making it more likely to damage the subfloor.

[0005] Additionally, repeat loads of drywall enter a building through the same entrance, often called the pull-in spot, and hallway(s), which increases the chance that a weak subfloor will experience a break or breech under the weight of the cart. Once the floor is damaged by high volume cart repetition, the floor is no longer safe for additional cart deliveries, so the drywall must be carried from that point further into the building or the jib is haled until additional plywood is installed over the weak spot. Unloading and removing the cart can result in an extra 10-15 minutes of deliver time per job, if only one incident occurs during the delivery. If multiple weak spots are encountered by a cart, the deliver could take an extra half hour to an hour, which is lost money for the company. Moreover, if the deliver company supplies plywood to reinforce any weak areas that is an additional expense that cuts into a delivery being profitable.

[0006] There is a need for a portable mat that can be laid over a subfloor that has a strength sufficient for carts loaded with sheets of drywall to pass thereover repeatedly and that is reusable, thereby saving the deliver time and money. It is desirable that the portable mat is easy to carry, yet has sufficient length for entrances into buildings, such as down a hallway.

SUMMARY

[0007] In all aspects, a portable, foldable mat for construction sites is disclosd herein. The mat has an elongate body defining a plurality of panels each foldably connected to immediately neighboring panels thereof. The plurality of panels has an initial panel as a first end, at least one tertiary panel defining a second end, and an immediately neighboring second panel of the initial panel between the initial panel and the at least one tertiary panel. The plurality of panels is foldable upon one another beginning from the second end toward the first end of the elongate body onto itself repeatedly until any tertiary panels are contained between the initial panel and the immediately neighboring second panel of the initial panel. Each of the plurality of panels comprises a sheet of material having a load rating of at least 500 pounds. In one embodiment, each sheet of material is high density polyethylene (HDPE), which has a thickness in a range of 0.0625 inches to 0.5 inches, preferably 3/16 in or 1/8 in thick.

[0008] A first handle extends from the initial panel and a second handle extends from the immediately neighboring second panel at a position to align with the first handle when the elongate body is in a fully folded state. The first handle and the second handle are fixedly attached to a bottom surface of the elongate body. In one embodiment, the first and second handles are defined by an endless oval strap of material sewn to the initial panel and the immediately neighboring second panel. The endless oval strap has a central longitudinal axis aligned with a central longitudinal axis of the elongate body.

[0009] In one aspect, each of the plurality of panels comprises a covering encapsulating the sheet of material in a compartment. The covering comprises a continuous length of textile fabric or two elongate pieces of textile fabric sewn together to define each compartment. When the covering has the two elongate pieces of textile fabric, a first textile fabric, such as ballistic nylon or polyethylene fabric, defines a bottom surface of the covering and a second textile fabric, such as PVC fabric, defines a top surface of the covering. Each compartment is defined by sewn seams extending transverse to a central longitudinal axis of the elongate body between immediately neighboring panels, where in between immediately neighboring panels there are at least two of the sewn seams spaced apart a pre-selected distance from one another to define a hinge region of the covering.

[0010] In all aspects, a binding of textile material is sewn to the first textile fabric and the second text tile fabric collectively to define a periphery of the elongate body.

[0011] In all aspects, the plurality of panels is three or more panels. Depending upon the number of panels present, the elongate body can be at least six feet long or at least 8 feet long, or at least 10 feet long. Each of the plurality of panels has a width oriented parallel to the central longitudinal axis of the elongate body, wherein the width of each sheet of material is in a range of 16 in to 48 in, and the width of the elongate body is in a range of 24 inches to 50 inches.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. l is a photograph of the portable, foldable mat in its fully folded state.

[0013] FIG. 2 is a photograph of the portable, foldable mat in its fully open (unfolded) state with the bottom surface against the ground.

[0014] FIG. 3 is a photograph of the portable, foldable mat having a terminal panel folded onto its immediately neighboring panel.

[0015] FIG. 4 is a photograph of the portable, foldable mat having the terminal panel and its immediately neighboring panel both folded onto the nextmost neighboring panel. [0016] FIG. 5 is a photograph of the portable, foldable mat having the terminal panel, its immediately neighboring panel, and the nextmost neighboring panel all folded in that order onto a panel immediately neighboring the initial panel of the mat.

[0017] FIG. 6 is an image of a comer of a sheet of high density polyethylene.

[0018] FIG. 7 is a photograph of the bottom surface of the mat showing one embodiment of handles for the mat and an optional second embodiment of handles.

[0019] FIG. 8 is an enlarged photograph of a portion of the hinge seam between panels.

[0020] FIG. 9 is top plan view of the portable, foldable mat of FIG. 1 without a representation of the sewn seams.

[0021] FIG. 10 is a photograph of a doorway in a construction sight with a representation of the portable, foldable mat in a ramp configuration against a stud within a doorway opening.

DETAILED DESCRIPTION

[0022] The following description and drawings are illustrative and are not to be construed as limiting. In the drawings, like reference numbers indicate identical or functionally similar elements. Numerous specific details are described to provide a thorough understanding of the disclosure. In certain instances, however, well-known or conventional details are not described to avoid obscuring the description.

[0023] Referring to FIGS. 1-5, a foldable, portable mat 100 for subfloor reinforcement for delivering heavy materials at a construction site, for example, drywall on a wheeled cart, is shown. In FIG. 1, the mat 100 is in its fully folded, portable state. In FIG. 2, the mat 100 is in its fully open (unfolded) position. Sequentially from FIGS. 3-5 and back to FIG. 1, the various folding stages of the mat 100 are shown. The mat 100 has an elongate body 102, as best seen in FIG. 2, that is straight and is defined by a plurality of panels 104 foldable upon one another beginning from a first end 108 toward a second end 106 on to itself repeatedly until any tertiary panels 104c, 104d, 104e are contained between an initial panel 104a and an immediately neighboring second panel 104b of the initial panel 104a. As represented in FIG. 5, each of the plurality of panels 104 comprises a sheet of material 110 rated to support 500 pounds or more. In other embodiments, the sheet of material 110 is rated to support 1000 pounds, 1500 pounds, or 2000 pounds (any value in between). In yet another Still referring to FIG. 5, the mat 100 includes a first handle 112 extending from the initial panel 104a and a second handle 114 extending from the immediately neighboring second panel 104b at a position to align with the first handle 112 in the fully folded state as shown in FIG. 1.

[0024] Referring to FIGS. 1 and 9, the plurality of panels 104 is typically three or more panels with the elongate body 102 having a length (L _M ) of at least 6 feet. In another embodiment, the length (L _M ) is at least 10 feet. The length can be in a range of 4 feet to 18 feet. Each sheet of material 110 within each respective panel 104 has a width (Ws) oriented parallel to a central longitudinal axis (A _M ) of the mat 100 and a length (Ls). The width (Ws) of each sheet is in a range of 16 inches to 32 inches, and the width (W _M ) of the mat 100, which is perpendicular to the width (Ws) of each sheet, is in a range of 24 inches to 50 inches. The width (W _M ) may also include a distance (D _E ) from the edge of each elongate side of the mat 100 to the each of the plurality sheets 110. The panels 104 are spaced a distance (D _H ) apart from one another to define a hinge portion 118 therebetween. In one embodiment, the width (Ws) of each sheet is 24 inches. In another embodiment, the mat is 10 feet 8 inches long, has five panels each encapsulating a HDPE sheet that is 24 inches by 39 inches, and has a one inch hinge space between juxtaposed panels. In another embodiment, the mat is 20 feet long, has five panels, each encapsulating a HDPE sheet that is 48 inches by 24 inches, and has a one inch hinge space between juxtaposed panels. In this longer version, the 48 inches is oriented with the length of the mat and the 24 inches is transverse to the length. In each of these embodiments, the HDPE can be 1/8 in thick. The dimension ranges disclosed herein each include each value therein in inch increments, half inch increments, ¼ inch increments, eight inch increments. If the sheets are cut, each increment includes a cutting tolerance relative to the cutting device or measuring device used.

[0025] The mat 100 has a covering or casing 103 encapsulating each sheet of material 110 in a separate compartment. Each sheet of material 110 as noted above can handle loads of 1000+ pounds per wheel of a loaded drywall cart (“load rating”). In one embodiment, each sheet of material is a high density polyethylene (HDPE) sheet having a thickness in a range of 0.625 inches to 0.5 inches. In other embodiments, the HDPE sheet has a thickness of 1/8 inch, 3/16 inch, or ¼ inch. In another embodiment, the HDPE has a thickness of 3/16 inch. Other beneficial characteristics of each sheet is a material that is moisture and mildew resistant, odor resistant, and has long-term durability. HDPE has these beneficial characteristics and has excellent impact resistance, low moisture absorption, high tensile strength, is non-toxic, non-staining, chemical resistant, has good fatigue and wear resistance, and is resistant to organic solvents, degreasing agents, and electrolytic attack. A balance is needed between the impact strength of the sheet, the thickness of the sheet, and the weight of the sheet to provide a mat that is still portable (not too heavy to be carried by a user) yet meets the 1000+ pounds/wheel rating. For example, a sheet of HOPE with a rating of 1450 pounds per inch (PSI) for a drywall cart with four wheels and a maximum capacity of 2000 lbs. (i.e., 500 lbs per wheel) provides a safety rating of greater than 2.5 to about 3 times. In one embodiment, the HDPE is a Class A, type III HDPE, having a hardness, Shore D rating of 55-75. The density of the HDPE is in a range of 0.940 to 0.965, e.g., about 0.95, and the melt flow index is 7-25 g/10 min.

[0026] Referring now to FIGS. 1-5, 7, and 8, the mat 100 has a covering 103 sewn to encapsulate each sheet of material 110 in its own compartment and to define hinge regions 118 between immediately neighboring pairs of compartments that are foldable one upon the other. The elongate body 102 can be defined by a continuous length of textile fabric or two elongate pieces of textile fabric sewn together to encapsulate each of sheet of material 110 in separate compartments. The textile fabric can be nylon, such ballistic nylon, or a polyethylene fabric, such as Tyvek. Ballistic nylon is any nylon fabric that is made with a "ballistic weave", typically a 2x2 or 2x3 basketweave. The ballistic nylon can be woven from nylon yarns of various denier such as 840 denier to 1680 denier, more preferably a denier greater than 1000. In one embodiment, the ballistic nylon selected had 1050 denier by 1050 denier and a basketweave 22 x 21 construction. The textile fabric is preferably mold and mildew resistant and abrasion resistant. The abrasion resistance of ballistic nylon is such that the mat 100 can be pulled along a subfloor over nails, screws, metal scraps, etc. without significant damage thereto, and even if a hole is formed therein, the material is such that a hole does not typically get larger during continued use of the mat.

[0027] With reference to FIG. 10, the mat 100 can have two different elongate pieces of textile fabric sewn together, a top textile fabric 140 and a bottom textile fabric 142. Top being the surface facing upward toward the sky during use and the bottom being the surface in contact with the ground or floor of a structure during use. In one embodiment, the bottom textile fabric 142 is a ballistic nylon as described herein and the top textile fabric 140 is a vinyl coated polyester. The vinyl coated polyester, often called a PVC fabric, provides better grip for the top surface than the ballistic nylon, especially if damp or wet. Ballistic nylon when damp tends to stretch or loosen relative to the HDPE sheets, which was not desirable.

In contrast, the PVC fabric does not stretch when damp or wet. The PVC fabric can be an 18 oz, 22 oz, 28 oz, or 40 oz PVC fabric, preferably the 22 oz PVC fabric. The 22 oz PVC fabric helped reduce shipping weight relative to the 28 oz and 40 oz PVC fabric while providing sufficient grip to the top surface for the user’s shoes. In one embodiment the PVC fabric is a 1500 x 1500 denier polyester that is a 16 x 16 woven fabric that has a coating weight of 16 +/- 0.5 oz/yd ² .

[0028] A hinge region 118 is most clearly seen in the enlarged view of FIG. 8. Each separate compartment is defined by sewn seams extending transverse to the central longitudinal axis (A _M ) of the elongate body 102. Immediately neighboring separate compartments, in particular the sewn seams 120, referred to as sewn hinge seams, defining the compartments are separated a pre-selected distance (D _H ) from one another by a hinge portion or hinge region 118 portion of the length of the covering material. A binding 122 (also best seen in FIG. 8) of textile material is sewn to each side of the elongate body 102 defining a periphery thereof. The binding may be a nylon material, such as the same material as the covering or a webbing, which may be nylon or a PVC fabric.

[0029] Referring now to FIG. 7, the first handle 112 and the second handle 114 are each fixedly attached to a bottom surface 109 of the elongate body 102. In one embodiment, the first and second handles 112, 114 are defined by an endless oval strap 116 of material sewn to the initial panel 104a and the immediately neighboring second panel 104b. The endless oval strap 116 has a central longitudinal axis (A _H ) aligned with a central longitudinal axis (A _M ) of the mat 100. The handles 112, 114 are preferably made of a durable webbing material, such as nylon webbing or PVC fabric. As such, the first handle 112 lies generally flat such that wheels of a drywall cart can easily roll over it or it can be tucked under the initial panel 104a.

[0030] Still referring to FIG. 7, in another embodiment, represented by the dashed lines in FIG. 7, the mat 100 may include a first fastener 130 extending from either the initial panel 104a or the immediately neighboring panel 104b and a second mating fastener 132 on or extending from other of the initial panel 104a or the immediately neighboring panel 104b.

The first fastener and the second mating faster 130, 132 hold the mat closed in its fully folded state when mated to one another. The first fastener and the second mating fastener 130, 132 may be hook-and-loop material, snaps, a hook (open or openable) and eyelet or loop configuration, magnets, tie strings, etc. With these fasteners present, the first and second handles 112', 114' can be oriented transverse to the central longitudinal axis (A _M ) of the mat 100 and can extend from either or both elongate sides of the mat. [0031] Turning again to FIG. 10, one of the useful advantages of the mat 100 is its ability to form the equivalent of a ramp in one or more of its partially unfolded positions, in particular relative to a stud that has yet to be cut out of the base of a doorway. Here, the mat 100 has simply been opened from its fully folded position by folding the initial panel 104a away from the remainingly folded panels, which places tertiary panel 104c facing up next to the initial panel 104a. The remainingly folded panels are positioned juxtaposed to the stud with the initial panel extending therefrom away from the stud and doorway, thereby forming a stepped configuration that acts as an “up” ramp capable of having a loaded drywall cart wheeled thereover. A second matt 100 can be opened in the same manner and placed juxtaposed to the opposite side of the stud to form a “down” ramp.

[0032] It should be noted that the embodiments are not limited in their application or use to the details of construction and arrangement of parts and steps illustrated in the drawings and description. Features of the illustrative embodiments, constructions, and variants may be implemented or incorporated in other embodiments, constructions, variants, and modifications, and may be practiced or carried out in various ways. Furthermore, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative embodiments of the present invention for the convenience of the reader and are not for the purpose of limiting the invention.

[0033] Having described the invention in detail and by reference to various embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention which is defined in the appended claims.

[0034] What is claimed is: