1. Field of the Invention
This invention pertains to the field of portable, rigid structures. More particularly, it pertains to a plurality of individual members that may be interconnected to form a rigid structure to support a wide selection of cover means to form a covered enclosure to enclose a variety of activities including golfing practice, T-ball batting practice, soccer practice, tennis practice, and even extending to events that are non-sports oriented such as enclosing weaponry such as army tanks and the like for military use.
2. Description of the Prior Art
Man has constructed enclosures since he first walked on the earth. Many of these structures have been carved out of monolithic rock, built of palm leaves or branches, and dug in hill sides. These structures all have one fundamental limitation, namely that they cannot be easily disassembled and removed to a remote location for re-assembly.
Portable structures, i.e., those that may be disassembled and removed to another location for re-assembly, are more difficult to design and construct because of a number of additional requirements. For instance, the design should be quickly and easily assembled and disassembled. The individual members making up the structure should be easily packageable for convenient portability to the remote location. The individual members should be lightweight, yet strong, and resist physical loading from overlying covers and from torsional loading due to wind effects and other environmental pressures.
The members must be interconnectable using few tools and, most desirably, using only hand labor. Further, for commercial acceptance, the members should be made of low-cost, strong and durable materials capable of withstanding a wide variety of natural effects such as rain, wind, heat or temperature, and the acidic effects of our environment. Disassembly should be easily accomplished and the parts easily and quickly stacked and crated for shipment to the new location. Finally, the individual members should be able to be arranged in a wide variety of configurations as well as being assembled into a strong, rigid enclosure that will remain fixed even when long spans are involved.
The prior art has mainly concentrated on use of thin-walled aluminum tubing or nylon rods to form the enclosure. In most cases, the overlying covering is designed to cooperate with the tubes or rods in their assembled form to provide the required strength to resist loading due to environmental effects. This requires that the structure always be assembleable into the same configuration and not change its size or shape. Aluminum also has been found to degrade in the presence of salt water, ground water and other environmental conditions so that its longevity is questionable, at best.