Abstract:
A flexible structure is composed of a plurality of pole or rod elements including at least two series of rows of such rods, the rods of each row being substantially parallel to one another. The rows are intersecting, but are uniform in respective orientation. The rods are stabilized at the intersections by fittings which permit relative sliding movement of restricted degree. These fittings are secured to a flexible membrane or body portion. 
     A swivel relation exists between the fittings and related components. 
     Modification of the fittings to provide multiple layer body portions is achieved through the application of spaced layers of material.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a flexible structure having a broad range of utility. Illustratively, the structure may be embodied in a tent or enclosure, a kite, a boat, or other environments wherein a flexible body is employed. 
     2. Statement of the Prior Art 
     This invention is to some extent an extension or improvement on the subject matter shown in my prior U.S. Pat. No. 3,863,659. Other pertinent prior patents known to me include the following: 
     
         ______________________________________Patent No.  Patentee     Issue Date______________________________________2,914,074   Fuller       March 1, 19573,006,670   Schmidt      Oct. 31, 19613,269,398   Holbitz      Aug. 30, 19663,710,806   Kelly et al  Jan. 16, 19733,744,191   Bird         July 10, 19733,838,703   Zeigler      Oct. 1, 1974.______________________________________ 
    
     SUMMARY OF THE INVENTION 
     The present invention provides a flexible structure of unlimited utility and features a flexible membrane or body portion having a series of rods or poles arranged in intersecting rows. These are stabilized at intersection points by fittings which permit slidable movement. Such sliding movement may be effected in several manners, but preferably is through the use simply of an annular element of sufficient dimension to accommodate the poles in sliding fashion. 
     The structure provided hereby is characterized by a substantial strength to weight ratio in relation to its enclosed volume. This is believed to result from a synergetic inter-action between the outwardly stressed poles or rods, and the annular elements secured to the membrane. The slidable nature of the association of these components, with the annular elements attached to the membrane, permits the formation of multi-faceted, complex structures with ease and speed. Such structures are easily disassembled as well. 
     In principal embodiments of the invention, a swivel relationship exists between the annular elements and related components permitting self-adjustment of the components. 
     Other and further objects and advantages of the invention will become apparent to those skilled in the art from a consideration of the following specification when read in conjunction with the annexed drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a dome-like structure formed in accordance with the present invention; 
     FIG. 2 is an enlarged fragmentary view of the structure; 
     FIG. 3 is a further enlarged sectional view taken substantially on line 3--3 of FIG. 2, looking in the direction of the arrows; 
     FIG. 4 is a view similar to FIG. 3 showing a modification employed in forming a multi-layer structure; 
     FIG. 5 is another fragmentary top perspective view showing a first modified form of intersection; 
     FIG. 6 shows another type of crossover; 
     FIG. 7 discloses another modification; and 
     FIG. 8 shows still another form of intersection. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The dome shown in FIG. 1 and identified by reference character 10 is representative of the forms in which the structure hereof may be embodied. The tent-like form is of a broad range of utility as an enclosure. Other environments of employment of the structure are set forth hereinabove. 
     A basic component of the structure is a flexible membrane or sheath 12 having an inner surface 14 and an outer surface 16. The membrane is formed of plastic or other material and has the characteristic of being stretchable in multiple, directions. Throughout its extent the membrane has connection locations such as apertures 18 formed therein, said apertures being arranged in rows. 
     FIGS. 2 and 3 disclose a first basic form of fitting assembly 20 hereof. A fitting assembly 20 is provided for each of the apertures. The assemblies 20 each comprises an outer base 22 and an inner base 24. The bases have inside walls 26, 28, respectively, provided about their outer circumferences with projecting teeth 30 and 32. These teeth grip the material of the membrane to insure a tightly sealed relation beween the fitting and the membrane. The fitting assembly further includes means extending through the aperture to clampingly secure the fitting to the membrane. In FIG. 3, such means is shown as comprising a shaft 34 extending vertically from the inner base 24. The shaft has an enlarged, tapered plug 36 on its outer end. Formed in the outer base 22 is a chamber 38 shaped to correspond to the configuration of the shaft 34 and plug 36. The fitting is of rubber or a similar material, and thus, the plug is engageable in the chamber. The plug and shaft are extended through the aperture and into engagement in the chamber, thus locking the bases on opposite sides of the membrane. 
     Extending vertically from the outer base 22 is a vertical stem 40. The stem is provided with a swivel pin 41. The swivel pin 41 is seated in a bore in an enlarged annular ring member 42 mounted on the stemm 40. The swivel pin has a top plate 45 which permits disassembly. The ring member is rotatable to permit variance in orientation, for accommodation of the intersecting rods at various angles. 
     The base 24 is formed with an interior hole 47 from which items may be suspended. 
     The invention has, as an important structural feature thereof, two or more intersecting series of support rods which coact with the membrane 12 and fittings 20 to form the structure hereof. This includes a first series of rods 44 which extend substantially parallel to one another, and a second series of rods 46, also mutually generally parallel. The rods of each series are constructed of material, such as a solid or tubular resinous, or metallic substance, which is rigid and yet permits flexation. The rods are flexed in arch form during assembly and are of varying lengths depending upon location. 
     The rods are positioned along the rows of apertures, and extend in sliding relation through the ring members 42 of the fittings. The rods of the second series 46 intersect those of the first series and pass under those of the first series, there being a relatively loose fit through the ring members 42. The rods are stabilized by the omnidirectional tension of the membrane. 
     FIG. 4 shows a modified form of fitting, components corresponding to those in the first described form being identified by like reference characters with a letter a appended thereto. The fittings 20a have an outer base 22a which is snap fit to an inner base 24a. Depending integrally from the inner base is a spacer extension 100 having a disc member 102 thereon. The disc member 102 has a flat lower face 104 with teeth 106 and contacts an inner membrane layer 108 about an aperture 110 therein. The apertures 110 in the inner membrane layer are vertically aligned with the apertures of the outer layer. The disc member 102 is secured to the inner membrane layer 108 by a lower disc 112 having an inside face 114 with teeth 116, and having a prong 118 with an enlarged head 120 -- a suspension hole 47a being provided therein. The prong and head extend through the aperture 110 and seat in a correspondingly shaped socket 122 formed in the disc 102. The second form of the invention therefore provides for two layers of membrane, for insulation or added strength. 
     In FIG. 5, still another modification is shown. Here, the intersection of the rods from the first and second series thereof is accomplished with a fitting 20b similar to the fitting 20. The ring member 42b is of reduced diameter however, and will accommodate only a single rod. A swivel pin 200 is extended through an opening formed in the top of the ring member, and has an enlarged end 202 to prevent withdrawal. A second ring member 204 has an opening in its lower end, and the pin extends therethrough again having an enlarged end 206. This constitutes another means to permit limited relative sliding movements of the rods at their intersection points. 
     In some configurations of a more complex nature than the basic concave-convex form shown in FIG. 1, additional series of rods may be required. FIG. 6 illustrates an embodiment wherein three intersecting series of rods 44c, 46c and 300 are employed. There a third ring member 302 is added above the ring members 204c and 42c. This is accomplished through a swivel pin 304 identical to the pin 200 described above. This arrangement may be further modified by adding rings to provide for any number of tiers of rods. 
     FIG. 7 shows yet another form in which the membrane 12d is imperforate. Fittings 20d comprise a central body 400 having shallow outwardly threaded end portions 402 and 404. An upper body 406 has a socket 408 with threads 410 interfitting with the end portion 402. A ring member 412 has an aperture 414 therein in which a stem 416 of the upper body is pivotally mounted. The ring is not detachable but is pivotal relative to the body 406. A lower body 428 is formed with a threaded socket (not specifically shown) and has a depending oval ring 430. This central body 400 engages the imperforate outer membrane 12d and clampingly engages it in the socket 408 between the loosely fitting screw threads, while the lower body socket is clamped to the inner membrane 108d in similar fashion. The connection is established at connection locations which are suitably determined on the respective membranes. 
     Finally, in FIG. 8, a non-complex form of fitting 20e is used wherein the member 12e is formed with slits 18e comprising the connection locations. The fittings comprise discoidal bases 500 having a punched or struck tab 502. The tab includes a stem section 504 bent to substantially perpendicular relation to the base and having an elongated ring member 506. The tabs extend through the slits 18e to receive the appropriate poles.