Convertible support apparatus

A convertible support apparatus for supporting an object over a ground surface is convertible between an operating configuration and a storage configuration. The support apparatus may comprise side members, a support area configured to connect to the side members, and a bow truss configured to bow. When the device is assembled in the operating configuration, both the support area and the bow truss are connected between the side members and the bow truss is configured to bow and place the support area under tension. The bow truss may comprise a bow tube connected between two foot fixtures. In one embodiment, when the apparatus is supporting a sufficiently heavy object, the bow tube will bow and contact the ground surface and provide additional support to the apparatus.

TECHNICAL FIELD

The present invention relates to a support apparatus, and more particularly, some embodiments relate to a bed convertible between an operating configuration and a storage configuration.

BACKGROUND OF THE INVENTION

A large variety of beds for outdoor sleeping are available on the market. Outdoor portable beds are generally used for camping, sleeping in rustic settings, or for relaxing at places like the beach. Most outdoor beds fold in some manner to make storage and carrying easier. Such beds are usually constructed with a metallic or wood frame with a fabric membrane stretched tightly across the frame as the sleep surface and are usually called cots. The alternatives to cots for camping are foam pads, air mattresses, and hammocks. Cots are generally considered to be more comfortable than foam pads or air mattresses, but are usually much heavier. Backpackers, motorcycle riders, kayakers, bicyclists rarely carry cots since they are too large, even when folded, and are too heavy. Lightweight travelers would like to have a comfortable bed that was as lightweight as a foam pad and folds down to a small size to fit in a backpack. However, cots are typically about 12 inches tall and 7 feet long and will not fit inside a typical lightweight camping tent. Hammocks can be small and light, but require two trees or poles to function. Many camping sites have no trees or poles. Hammocks also deliver a very curved sleeping surface that is not at all like the planar bed at home, causing most users to be unable to sleep well.

Beach visitors may prefer a bed that is compact in the car and comfortable on the beach. Families with limited space may like to have an easy to store spare bed for overnight guests. A common complaint from users of cots is that they stretch and collapse. This happens because the tubular frame design is easy to accidentally overstress. Common fabrics will gradually stretch to the point of sagging to the ground. Since the bed is a foot above the floor, it is easy for a heavy person to produce stresses that break the frame or tear the fabric. Therefore, there is a need for an improved support apparatus for persons and other objects.

BRIEF SUMMARY OF EMBODIMENTS OF THE INVENTION

According to one embodiment of the invention, a convertible support apparatus for supporting an object over a surface is convertible between an operating configuration and a storage configuration. The support apparatus may comprise side members; a support area configured to connect to the side members; and a bow truss configured to bow and flex when connected between the support members. The bow truss comprises a first bow tube connected between two foot fixtures. When the device is assembled in the operating configuration, both the support area and the bow truss are connected between the side members and the bow truss is configured to bow and place the support area under tension. When the apparatus is placed on a ground surface in the operating configuration without the object, the two foot fixtures are configured to touch the ground surface and the bow tube is configured to suspend over the ground surface out of physical contact with the ground surface. When the support area is loaded with the object, the bow tube will deflect. If the object is heavy enough, the bow tube will deflect downward enough to contact the ground surface.

In another embodiment of the convertible support apparatus, the support area is flexible and the foot fixture has a first void and a second void. The first void may be configured to receive a plurality of bow tubes and a plurality of side members and the second void may be configured to receive the support area. In a preferred method of use, the two voids receive the bow tubes, side members and support area when the support apparatus is in a stowed configuration. In an alternative embodiment, the foot fixture has a single void configured to receive a plurality of bow tubes, a plurality of side members and the support area when the support apparatus is in a stowed configuration.

In a further embodiment, the convertible support apparatus has at least two foot fixtures for contacting a support surface. When the support apparatus is assembled in the operating configuration and supporting a sufficiently heavy object, the foot fixtures are configured to support the apparatus on the ground surface and the bow tube is configured to bow and contact the ground surface beneath the foot fixtures, thus providing an additional contact point for supporting the object.

In another embodiment, the apparatus is configured such that when placed on a flat ground surface, the foot fixtures touch the ground surface and support the apparatus and the bow tube is configured to contact the ground surface and support the apparatus.

In still another embodiment, the apparatus has a second bow tube disposed adjacent to the first bow tube and connectable to the foot fixtures. In another alternative embodiment, the second bow tube may be twisted around the first bow tube.

In yet a further embodiment, the bow tube comprises a female member and a male member receivable into the female member and the foot fixture configured to receive the bow tube.

In another embodiment, the foot fixture has a hook configured to connect the foot fixture to the side member.

In a further embodiment, the support area is flexible and the apparatus is configured to support the object at a height over the ground surface and the apparatus weighs less than 1% of the weight of the object it is configured to support.

In still another embodiment, an apparatus for supporting objects or persons includes two spaced apart side members; a support area connected between the side members; and a first bow truss connected between the side members. The bow truss is comprised of a first bow tube connected between two foot fixtures. The bow tube is configured to bow when the bow truss is connected between the side members, bias the side members apart, and place the support area under tension. In one embodiment, the apparatus may be convertible between an operating configuration and a storage configuration.

In yet a further embodiment, a method of supporting an object over a ground surface includes suspending a flexible support area between two side members; connecting at least two foot fixtures to the side members, so that the foot fixtures support the side members over a ground surface; and connecting a bow tube between the foot fixtures.

In another embodiment, the method of supporting an object over a ground surface of may further comprise bowing the bow tube so that it contacts the ground surface using the weight of the object on the flexible support area.

In a further embodiment, the method of supporting an object over a ground surface may include: connecting first ends of two bow tubes into a first foot fixture; connecting second ends of the two bow tubes into a second foot fixture; and rotating one of the foot fixtures by 180 degrees.

DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

From time-to-time, the present invention is described herein in terms of example environments. Description in terms of these environments is provided to allow the various features and embodiments of the invention to be portrayed in the context of an exemplary application. After reading this description, it will become apparent to one of ordinary skill in the art how the invention can be implemented in different and alternative environments.

Referring toFIGS. 1,5and7the present invention is directed toward a convertible support apparatus10for supporting an object15or a person over a ground surface20. The convertible support apparatus10is convertible between an operating configuration, shown inFIGS. 1,5and6, and a storage configuration. In a preferred embodiment, the storage configuration is shown inFIG. 12, however, the term, “storage configuration,” generally refers to the support apparatus disassembled from the operating configuration. Thus, there are virtually an unlimited number of storage configurations, for exampleFIG. 11is another storage configuration. The support apparatus10may comprise side members25and a support area30configured to connect to the side members25. The apparatus10also includes a bow truss32, as illustrated inFIGS. 2 and 3, and is configured to resiliently bow and flex. When the apparatus is assembled in the operating configuration, both the support area30and the bow trusses32are connected between the side members25and the bow trusses32are configured to bow and place the support area30under tension. In one embodiment, referring toFIGS. 3 and 4, the bow truss32further comprises a bow tube35connected between two foot fixtures40and the foot fixtures are configured to connect the bow truss32to a side member25.

Referring toFIG. 4, in a preferred embodiment, the foot fixture40typically has a circular or oval cross-section and may be about 5 inches in height. The foot fixture40may be an injection molded plastic ring. The foot fixture40may have first45and second50holes to allow an end55of a bow tube to be inserted therein, parallel to the plane of the foot. When the other end60of the bow tube is inserted into a first45or second50hole of another foot fixture40, as illustrated inFIG. 3, the two feet40are held a fixed distance apart. Referring toFIGS. 8 and 12, the foot fixture40has a hook65located at a top of the foot fixture40. The hook65is configured to clip onto the side member25and, in one embodiment, referring toFIG. 15, clip to a side member25that has been inserted into a sleeve70of the support area30, through a window68of the sleeve70.

Referring toFIGS. 5 and 6, the support apparatus10may serve as a bed for persons to sleep on. In one embodiment, the support area30may be comprised of a fabric panel30tensioned between two side members25or poles that are supported by a plurality of bow trusses32. The fabric panel30can be made from any low stretch fabric but is preferably sewn from composite fabric made for sails on racing sailboats to achieve the lowest weight. The fabric panel30has dimensions that can be varied to suit the application, but may in one example be about 25 inches wide and 75 inches long to accommodate adult human body sizes. The fabric panel30may be sewn with a sleeve70along the full length of each long side75to accommodate a side member25or pole that is configured to be inserted therein. In one embodiment, the side pole25may be constructed of segments of aluminum or carbon fiber, similar to common tent poles, to allow it to be disassembled and stored in a compact form, for example as shownFIG. 11. The sleeve in the fabric panel may have cutouts or windows68, and in one example, the windows68are spaced every 15 inches to allow the bow trusses32to attach across the fabric surface30to the side pole25on each side75.

Referring toFIGS. 3,5and6, in one example embodiment, a plurality of bow trusses32, typically from four to six in number, are used to bias the two side poles25apart and create a side-to-side tension in the fabric panel30. In the present example, there are no structural members that provide tension in the lengthwise direction, although other embodiments might include such a feature. Each bow truss32may be comprised of a small diameter connecting tube35and be connected to a removable foot fixture40at each end. The bow tubes35can be made from aluminum, titanium, carbon fiber, or other light but strong material. For ease of transporting, illustrated inFIG. 10, the bow tubes35may comprise two sections, a male section80that is receivable into a female section85, such as a tent pole tube.

Referring toFIG. 7, the width of the fabric30between the two side poles25is less than the unbent length of the bow truss32. Thus, to alter the horizontal distance between the two feet40one bends the bow truss32. This can be achieved by, for example, if a sufficient weight15is placed on the support area30. The bow truss32be must be bent in order to clip a foot40onto a side tube25. The bend in the bow truss32produces tension in the fabric panel30. However, this tension alone may not be sufficient to support an adult human body. To deliver a high level of tension, the bow truss should preferably be placed on a sold surface, like the ground. When resting on a flat surface and if sufficiently tensioned, the bow truss32will touch the ground at three places90,95,100which include the two feet90,95and the center100of the bow tube35, which is bowed down when the support apparatus10is assembled in an operating configuration.

If a person lies down on the support apparatus10or a sufficient weight15is placed thereon, the fabric panel30is pushed downward, creating tension which pulls the two side poles25together. This force attempts to rotate105both feet inward. This rotation105bends the bow tube35downward where it touches the ground surface20in its middle100. The contact with the ground surface20shortens the beam length of the bow tube35by 50%, increasing its effective stiffness by a factor of nine. This produces a dramatic increase in the resistance of the foot40to rotation, thus increasing the tension of the fabric panel30.

In one embodiment, the dimensions of the support apparatus10are optimized such that a prone body results in the bow tube35bending and the fabric panel30deflecting such that the buttocks almost touch the ground. Structural failure of the bow trusses32, side poles25or feet40may be prevented by the body touching the ground. Sitting or standing on the apparatus10will press the section of the fabric panel30being sat or stood on, flat to the ground, limiting the stress on other frame elements. Other apparatus or bed designs that support objects15or persons higher off the ground surface20require thicker and heavier elements to withstand large point loads without failure, thus becoming very heavy and bulky.

In a further embodiment, each bow truss32can be tuned to allow the support area's30tension to be set to a lower level for the foot end of the bed, allowing a sleeper's legs to slant down at a more comfortable angle. This can be done by shortening the length of the bow tube35or by using feet40that have several holes45,50drilled in the wall of the feet40allowing the bow tube35to be inserted at different initial heights above the ground surface. If the bow tube is inserted in hole45, the bow tube will initially be positioned higher above the ground surface than if inserted in hole50. This will allow the fabric support surface to sag more before the center of the bow tube contacts the ground surface, at which point the support tension in the fabric increases by a factor of nine, thus producing a softer feel for the fabric surface. For a higher load bearing zone, a longer bow tube can be used. This will result in the bow tube touching the ground surface with the initial installation of the bow truss producing maximum tension on the fabric surface with the first pound of load weight.

Referring toFIGS. 2 and 6, two bow tubes110can be used to double the tension delivered by a single bow tube35. A relaxed tension at the foot end can also be achieved by adjusting the support area30to a wider width as it nears the end of the apparatus10configured to support light weight while using a constant length for all the bow trusses32.

The convertible support apparatus10can be assembled with a varying number of bow trusses32to accommodate light to heavy objects or people. A short bed for a child may have only three bow trusses. An embodiment for a 300 lb person may have six bow trusses to provide sufficient support. Since being light in weight and being capable of fast setup is valued by most users, the minimum number of bow trusses32is desirable for any given weight range. Since the weight of human body is not linearly distributed, the placement of the bow trusses32or double tube bow trusses110can be matched to the body.

The convertible support apparatus can be dissembled and stored in a smaller volume than prior art beds allowing it to be easily carried on bicycles, kayaks, motorcycles and in hiking backpacks. The long side pole that is inserted into the fabric sleeve consists of five segments to allow folding to under 16 inches in length. The segments have an insert that slips inside the neighboring segment to make a very stiff pole. Each bow tube35may be comprised of two pieces, male and female, that slip together using an insert connection. In one example, these pieces are individually under 16 inches in length. The fabric component can be folded into a small bundle, illustrated inFIG. 9, that slips inside a tubular stack made from the collection of oval feet, illustrated inFIGS. 8 and 12. Then, the poles and bow tubes35can be slipped into the voids in the stacked feet beside the fabric, thus making a very compact package that is approximately 16″ long and four inches diameter, for example. Prior art cots have poles and legs made from large cross-section round or square metal tubing or wood. Most such camping cots usually fold in half and some can then be rolled in a bundle of approximately 20 times the stored volume of embodiments of the present invention.

In another embodiment, referring toFIGS. 4,8and12of the convertible support apparatus, the support area is flexible and the foot fixture has a first void120and a second void125. The first void may be configured to receive a plurality of side members and the second void may be configured to receive the support area and a plurality of bow tubes. In a preferred method of use, the voids receive the bow tubes, side members and support area when the support apparatus is in a stowed configuration. In an alternative embodiment, the foot fixture has a single void configured to receive a plurality of bow tubes, a plurality of side members and the support area when the support apparatus is in a stowed configuration.

In still another embodiment, referring toFIG. 13, the bow truss32has a second bow tube35disposed adjacent to the first bow tube35and connectable to the foot fixture40. Alternatively, referring toFIG. 2, the second bow tube35may be twisted around the first bow tube35.

In a further embodiment, the support area is flexible and the apparatus is configured to support the object at a height over the ground surface and the apparatus weighs less than 1% of the weight of the object it is configured to support.

In yet a further embodiment, referring toFIG. 16, a method of supporting an object over a ground surface includes the step300of suspending a flexible support between two side members; in a step305, connecting two foot fixtures with a bow tube, connecting one foot fixture to a side member, and in a step315bending the bow to allow the second foot fixture to hook onto the second side member.

In another embodiment, referring toFIG. 17, the method of supporting an object over a ground surface of may further comprise a step320of bowing the bow truss so that it contacts the ground surface using the weight of the object on the flexible support area.

In a further embodiment, referring toFIGS. 13 and 14, the method of supporting an object over a ground surface may include: connecting first ends of two bow tubes into a first foot fixture (seeFIG. 13); connecting second ends of the two bow tubes into a second foot fixture; and rotating one of the foot fixtures by 180 degrees (seeFIG. 14).