Collapsible ground sheet

Abstract

A collapsible ground sheet has a floor made of a sheet of flexible, waterproof or water-resistant material, and walls attached to the floor and extending from the floor in a top direction. The walls are arranged about the periphery of the floor in series in a ring formation such that each of the walls has two neighboring walls. Each wall has a fabric portion and a wire loop, the wire loop disposed near the periphery of the fabric portion such that the fabric portion is supported by the wire loop. Each of the walls attached to its two neighboring walls by hourglass-shaped gussets made of a sheet of flexible material.

Claims

1. A collapsible ground sheet comprising: a floor made of a sheet of flexible, waterproof or water-resistant material, the floor having a periphery and a top direction; a plurality of walls attached to the floor and extending from the floor in the top direction, and arranged about the periphery of the floor in series in a ring formation such that each of the walls has two neighboring walls; each of the walls comprising a fabric portion and a wire loop, the wire loop disposed near the periphery of the fabric portion such that the fabric portion is supported by the wire loop; and each of the walls attached to its two neighboring walls by hourglass-shaped gussets made of a sheet of flexible material; wherein the plurality of walls comprises more than six walls; wherein each of the walls has a length and a height, wherein the ratio of length to height is in the range of 3.8 to 4.2.

2. The collapsible ground sheet of claim 1 wherein each of the walls has a length and a height, wherein the ratio of length to height is approximately 4.

3. A collapsible ground sheet comprising: a floor made of a sheet of flexible, waterproof or water-resistant material, the floor having a periphery and a top direction; a plurality of walls attached to the floor and extending from the floor in the top direction, and arranged about the periphery of the floor in series in a ring formation such that each of the walls has two neighboring walls; each of the walls comprising a fabric portion and a wire loop, the wire loop disposed near the periphery of the fabric portion such that the fabric portion is supported by the wire loop; and each of the walls attached to its two neighboring walls by hourglass-shaped gussets made of a sheet of flexible material; wherein the plurality of walls comprises more than six walls; wherein each of the walls has a length of approximately 32 inches and a height of approximately 8 inches.

4. The collapsible ground sheet of claim 1 wherein the material is synthetic fabric, laminated fabric, vinyl, linen, oilcloth, wool, or canvas.

5. The collapsible ground sheet of claim 1 wherein the fabric portion of the walls is made of the same material as the floor.

6. The collapsible ground sheet of claim 1 wherein the fabric portion of the walls is made of the same material as the floor.

7. The collapsible ground sheet of claim 1 wherein the wire support is attached to the fabric portion with bias tape.

8. The collapsible ground sheet of claim 1 wherein the plurality of walls consists of exactly eight walls.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of a ground sheet according to a non-limiting embodiment of the subject technology.

(2) FIG. 2 is a top plan view of a ground sheet according to a non-limiting embodiment of the subject technology.

(3) FIG. 3 is an elevation view of a ground sheet according to a non-limiting embodiment of the subject technology.

(4) FIG. 4 is a side, detail view of a ground sheet according to a non-limiting embodiment of the subject technology.

(5) FIG. 5 is the view of FIG. 3 with bias tapes partially removed to show the wire supports beneath the bias tapes.

(6) FIG. 6 is a photograph of the encased ground sheet according to a non-limiting embodiment of the subject technology.

DETAILED DESCRIPTION OF THE INVENTION

(7) According to a non-limiting aspect of the subject technology, as shown in Figures, ground cloth 1 comprises a floor 10 and walls 15 (only one is numbered in the Figures). Walls 15 are attached near a bottom portion thereof to a periphery of floor 10 by, for example, stitching.

(8) In an embodiment, floor 10 is made of a strong, flexible sheet of material, preferably waterproof or water-resistant material, non-limiting examples being synthetic fabric (for example nylon or polyester fabric), laminated fabric (i.e. a fabric base layer with a waterproof or water resistant layer or layers laminated to the fabric), vinyl, linen, oilcloth, wool, Gore-Tex® or canvas.

(9) Walls 15 are similar to each other in construction and comprise a fabric portion 16, which preferably is a strong, flexible sheet of material as previously described, and may be the same material as floor 10. Each wall 15 further comprises a support 17, which in an embodiment is a long loop of wire, for example steel wire, disposed near a periphery of fabric portion 16. In an embodiment, support 17 is a loop of resilient steel wire, for example, memory wire. In an embodiment, support 17 is steel memory wire having cross-sectional dimensions of 1 mm×3 mm. Support 17 is connected to fabric portion 16 of wall 15 and disposed to support it in a substantially vertical position when ground cloth 1 is deployed on a ground surface. In an embodiment in which support 17 is a loop of wire, support 17 is disposed as shown near a periphery of fabric portion 16. In this embodiment, support 17 may be attached to fabric portion 16 by a bias tape 22 overlying support 17 and attached to fabric portion 16 about its periphery, for example, overlapping the edge of fabric portion 16 and overlying support 17, and stitched to fabric portion 16, thereby enclosing support 17 within the bias tape 22 and holding support 17 in its position near the periphery of fabric portion 16. Other structures for attaching support 17 to fabric portion 16 are possible and are within the scope of the subject technology.

(10) Each wall 15 is joined to its neighboring walls to provide mutual support when ground cloth 1 is deployed on a ground surface. In an embodiment, walls 15 are joined by hourglass-shaped gusset 18, which may be of the same material as the floor 10 and fabric portions 16, stitched to the neighboring walls 15 and to the floor 10, thereby joining them together by a flexible connection.

(11) In an embodiment, ground cover 1 is configured as a regular polygon, for example an octagon. In this embodiment, floor 10 has the shape of the polygon, for example an octagonal shape, and when deployed, walls 15, being attached to the edges of the octagonally-shaped floor 10, and supported by supports 17 and the gussets 18, stand in a substantially vertical position about the octagon, so that the overall configuration of the ground cover 1 is octagonal in this embodiment.

(12) Due to its structure as described, ground cloth 1 can be easily collapsed and folded up for transport and stored in a carrying bag for that purpose. When folded, the walls 15 generally overlie each other while individual walls 15 are not themselves folded, rather the flexible floor 10 and gussets 18 are flexed and folded manually until the walls 15 are overlying each other in a stack to form a compact, relatively flat configuration that can be placed in the carrying bag. In a non-limiting embodiment, as seen in FIG. 6, the carrying bag including the collapsed ground cloth has the following dimensions: length 34 in., width 9.5 in., thickness ¾ in. In this folded configuration, while encased, the wire members may be temporarily bent slightly. The resiliency of the bent wire support members tends to exert a force which deploys the ground cloth 1 when it is removed from its carrying bag and manipulated to allow the ground cloth 1 to expand to its deployed state.

(13) The fabric material used for the floor and walls may be thinner and lighter than a traditional beach blanket, and thus the subject ground sheet is a lightweight alternative. An embodiment of ground sheet 1 weighs about three pounds and can easily be carried to the beach or park by a young person.

(14) Walls 15 each have a height 19 and a length 20 (which length 20 is measured along the longest axis of a wall 15, as shown). Height 19 is preferably high enough to reduce the amount of sand or other debris that is swept into the ground cloth by winds, etc. In an embodiment, height 19 is 8 inches or approximately 8 inches. (“Approximately” is used throughout to denote plus or minus 10%.) The length 20 is preferably such that the area of floor 10 is sufficient for the purpose of use as a ground cloth for one or more persons. In an embodiment, length 20 is 32 inches or approximately 32 inches, such that the area of floor 10 (in an octagonal embodiment) is 4,944 in{circumflex over ( )}2.

(15) The inventors have discovered in practice that the ratio of length 20 to height 19 is important in the performance of ground cloth 1 when deployed. For example, if the length-to-height ratio is too high, the walls 15 lack stability in use and tend to sag or flop over to one side rather than standing in an approximately vertical position as desired. In the octagonal embodiment described above, the length-to-height ratio is 4, which the inventors have discovered yields good results. A hexagonal ground sheet having a comparable area, with a wall length of 45 in and wall height of 8 inches (ratio 5.6), was found by the inventors to suffer from the problem of unstable walls. In various embodiments of the subject technology, the length-to-height ratio is 4, or approximately 4, or in the range of 3.8 to 4.2.

(16) Similarly, the inventors have discovered that the internal angle of the polygon has an effect on wall stability. The inventors have discovered that a polygon with more than six sides, for example, an octagon results in a more stable product than a hexagon.

(17) While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. It will also be understood that the present invention includes any combination of the features and elements disclosed herein and any combination of equivalent features. The exemplary embodiments shown herein are presented for the purposes of illustration only and are not meant to limit the scope of the invention.