Abstract:
An architectural structure is made of one or more walls, each wall consisting of a lattice of rigid cells hingedly interconnected and supported by frame members. The cells may have holes sized and constructed to make the walls suitable for playground equipment.

Description:
BACKGROUND OF THE INVENTION 
     a. Filed of Invention 
     This invention pertains to a novel modular structure for use on playgrounds, and other wall-type structures such as fencing and so on, and more particularly to a structure consisting of a several relatively flat cells having a preselected geometric shape which hingedly interconnected. 
     b. Description of the Prior Art 
     Typically playgrounds or other areas dedicated for children&#39;s activities include structures adapted for climbing. These structures are made either of metal bars, such as the well known monkey bars, or are cement structures. However these structures are usually unsafe and thousands of serious injuries every year. 
     Other structures have been proposed to replace the ones presently in use but with relatively little success. For example a net-like structure composed of circular plastic rings interconnected by straps is shown illustrated on page 14 of the Jun. 4, 1988 of the Israeli magazine Maariv. However, this structure is unsafe because it has holes of sizes and shapes which may entrap a child&#39;s head, hand, or foot. Other proposed architectural structures are shown in U.S. Pat. Nos. Des. 218,455; 3,974,611; 2,956,806; 4,603,853; and 3,970,301. However none these structures are acceptable because they are unsafe. Furthermore the structures shown in the above-mentioned references are two complicated and expensive to make, and are often unsuitable for outdoor installations. 
     OBJECTIVES AND SUMMARY OF THE INVENTION 
     In view of the above-mentioned disadvantages of the prior art it is an objective of the present invention to provide a structure which can be safely installed and used thereby avoiding crippling, and fatal injuries. 
     A further objective is to provide a modular structure which can be used in a virtually infinite number of configurations. 
     Yet another objective is to provide a structure which can be formed into aesthetically pleasing and colorful configurations so they are attractive to children. 
     Yet a further objective is to provide a modular structure which is made of materials which are safe for use by children, yet strong enough to withstand the natural elements whereby the structures can be installed outdoors. 
     Another objective is to provide a modular structure which is made of relatively inexpensive materials, and which can be easily assembled into various configuration on site. 
     Other objectives and advantages of the invention will become apparent form the following description for the invention. An architectural structure constructed in accordance with this invention include one or more walls, each wall consisting of a rigid frame, a plurality of flat rigid cells, and flexible hinge means for interconnecting said cells or connecting said cells to the frame so that there is no substantial space left therebetween, to avoid entrapping a child&#39;s head or limbs. The cells are preferably made of a high density plastic material capable of withstanding natural forces including wide temperature swings, wind, humidity, snow or rain without degradation. The hinges are preferably made of a nylon or other flexible material and are imbedded in the cells to reduce exposure to the elements or to vandalism. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a plan view of a basic cell used in a structure constructed in accordance with this invention; 
     FIG. 2 shows a side view of the cell of FIG. 1; 
     FIG. 3 shows a sectional view of the cell of FIG. 1 taken along lines 3--3 in FIG. 1; 
     FIG. 4 shows a partial sectional view of the cell taken along line 4--4 in FIG. 3; 
     FIG. 5 shows an isometric view of a hinge used to interconnect cells in accordance with this invention; 
     FIG. 6 shows a cross-sectional view of a cell connected to a frame member; and 
     FIG. 7 shows an elevational view of a modular structure constructed in accordance with this invention; and 
     FIG. 8 shows an elevated view of a cylindrical structure constructed in accordance with this invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the Figures, and more particularly to FIGS. 1-4, a modularity of the inventive structure described herein is provided by a basic cell which may be interconnected with other cells to produce a wall member of any desired shape and dimension for a modular structure. A typical basic cell 10 as shown in the Figures is generally flat (i.e. its overall length and width are much greater then its depth). The cell 10 may have any geometric shape, but preferably a shape should be selected which would permit several cells to be interconnected to form a large wall with substantially no holes therebetween which may entrap a child&#39;s head or limbs. In FIG. 1 cell 10 is shown to be generally hexagonal because this configuration can be used to construct a large number of different structures, however, the cell may also be square, rectangular, triangular, pentagonal, and so on. Preferably, all the edges of the cell are rounded to eliminate the risk of cuts and scratches. The cell 10 consists of a peripheral hexagonal member 12 with a substantially circular cross section as shown. Member 12 is defined by six straight edges 14. (Of course the number of edges 14 for each cell 10 depends on its geometric shape). Preferably, where two edges 14 meet, the cell 10 is rounded, as at corner 16. Member 12 is formed with circular throughholes 18, each throughhole 18 being disposed substantially in parallel with a corresponding edge 14 at a distance W as shown in FIG. 4. Each throughhole 18 is open toward an edge 14 by a channel 20. Adjacent to corner 16, each channel 20 is defined by two parallel walls 22, 24 formed in member 12 and separated by a distance A so that the channel has a uniform cross-sectional radial dimension therebetween. However, the channel also has a central section 20&#39; defined by two walls 26, 28 extending somewhat at angular, or radially with respect to the axis of throughhole 18. At the edges bordering on hole 18, the tangential or peripheral distance between walls 26, 28 is substantially equal to dimension A defined above. In the region defined by walls 26, 28, channel section 20&#39; has a cross sectional dimension which increases radially outward as shown in FIG. 3. At the two longitudinal ends of walls 26, 28, throughholes 18 are formed with two ramps 30, 32 as shown in FIG. 4. 
     Cell 10 further includes a web 34 extending inwardly from member 12. Web 34 may be continuous, or it may be formed with a substantially circular hole 36. The inner edge 38 defining hole 36 is preferably rounded as shown in FIG. 3. 
     The inventive structure also includes a plurality of hinges such as hinge 40 shown in FIG. 5. This hinge 40 consists of two cylindrical portions 42, 44 arranged substantially in parallel. The portions 42, 44 have a smaller diameter then the diameter of throughholes 18 in cell 10, and a length which is equal to or slightly smaller than the longitudinal distance between ramps 30, 32 shown in FIG. 4. Portions 42, 44 are connected by a coextensive hinging section 46 which is relatively flat, and which has a thickness slightly smaller than dimension A. Laterally, the distance between portions 42, 44 exceeds twice dimension W. 
     Hinge 46 may be used to couple a cell 10 to another cell or to a stationary frame. For example, FIG. 6 shows a stationary frame member 48 consisting of an elongated hollow tube 50 with a channel shaped member 52. Member 52 is secured to tube 50 by a weld 54, by an adhesive, or any other well-known means. Member 52 has a lateral opening 56. A cell 10 is secured to member 48 as follows. First one portion 42 is inserted into channel member 52 with the hinge web 46 extending through opening 56. A cell 10 is then mounted on hinge 40 by throughhole 18 until it passes one of the ramps, such as ramp 30 passes the hinge 40. The ramps 30, 32 and the inner wall of throughhole 18 are sized and arranged to capture a hinge 40 whereby once the a hinge is inserted therebetween an interference fit is formed between the ramps and the hinge thereby making it difficult to separate the hinge 40 from cell 10. Of course, a cell 10 may be secured to identical cell 10 in a similar manner. Importantly, because walls 26, 28 are disposed at an angle, they allow relative angular movement between a cell and frame member 48, or another cell 10. Furthermore hinge 40 may be made of a relatively flexible and a somewhat extendible or elastic material to permit adjacent cells 10 interconnected by hinges 40 to flex as well to pivot slightly relative to each other. 
     FIG. 7 shows how a modular wall 60 may be made of a plurality of cells 10 interconnected by hinges 40 an supported by a plurality of frame members 48. The frame members may be interconnected at the corners by corner balls 60. Furthermore some of the lower corner balls may be mounted on stationary support such as a post 62 fully or partially buried in the ground 66. Preferably, at the interface between a frame member 48 and basic cells 10, a second half-hexagonal cell 64 or a triangular cell 64&#39; may be used as shown in FIG. 7 to eliminate holes which may trap a child&#39;s limb or head. Cells 64, 64&#39; are formed with channel means for engaging hinges as described above. Several planar walls such as the wall shown in FIG. 7 may be interconnected to make any shape desired. Furthermore curved walls may also be formed to form cylindrical shapes as shown in FIG. 8 or any other shapes as desired. 
     It will be apparent to one skilled in the art that the modular structure described above can be used to make architectural objects of virtually infinite configurations. Objects used in playgrounds may be created by several walls formed as shown in FIG. 7, with the holes 36 being used by children as foot and hand supports. The flexibility provided by the hinges gives each wall or structure a semi-flexible feel similar to a rope net. Other architectural structures such as fences, gazebos, and so on may be made in a similar manner. For these structures, holes 36 need not be circular or may be omitted completely. The cells 10, frame members 48, and hinges 40 may be shipped separately and assembled at the site. 
     Preferably each basic cell 10 (and cell 64) is made of high impact, high density polypropylene material which resists wear and tear, and is not corroded or otherwise degraded when exposed even to wind, rain, snow, sun, salty air and so on. Each cell may be made for example by molding. If necessary, two substantially identical sections may be molded separately and joined by sonic welding to form a single, unitary cell 10. Preferably, hinge 40 is made of an elastic material such as nylon. The nylon may be reinforced by fiberglass strands especially in the area of the web to resist tearing. It should be noted that since most of nylon hinge is disposed inside throughholes 18, they will be protected from the elements or vandalism by the cells 10 or channels 52. The cells can have any shape or size. For example a hexagonal cell may have an overall length and width in the range of 5-16&#34; and a thickness in the range of from 1/2 to 11/2&#34;. 
     Frame members 48 with channel members 52 may be made of metallic material such an aluminum or aluminum alloy made for example by extrusion. For installations exposed to extreme weather conditions, such as the sea shore, the frame members are preferably galvanized or otherwise coated with a protective layer. 
     FIG. 8 shows a cylindrical structure constructed in accordance with this invention including two uprights 70, 72 and hoop-s 74, 76 supporting a plurality of interconnected cells 78. 
     Obviously numerous modifications may be made to the invention without departing from its scope as defined in the appended claims.