FIELD OF THE DISCLOSURE OF THE INVENTION
The field of this invention relates to reticulated frame structures and space frames, and particularly to a novel hub capable of joining structural frame elements of such structures.
BACKGROUND AND PRIOR ART OF THE INVENTION
A reticulated frame is often referred to as a space frame because it is capable of covering large spaces with little interior support. It is typically a lightweight rigid structure having interlocking struts connected to hubs in a geometric pattern similar to a bridge truss. Like the well-known truss, such frames are strong because of the inherent rigidity of triangular beam arrangements where flexing loads and bending moments are transmitted as tension and compression vectors along the length of the beams. Such frames are common in building construction such as large roof spans in modern commercial and industrial buildings. Notable examples are the Stansted airport terminal in London, the Bank of China Tower, the Louvre Museum Pyramid, the Rogers Centre in Toronto, Ontario, and McCormick Place Lakeside Center in Chicago, Ill., USA. Large portable stages and lighting gantries are frequently built from such frames with octet trusses which are the structures of choice for holding signs above roads and in stadiums. The following documents have cited my prior patent U.S. Pat. No. 8,820,025B1 and are considered prior art in this application: US20150059263A1 and US9212479B1 to Devrim Pacaci, entitled “Supporting Framework Having Connection Hubs;” US20-150101645A1 to Garden Right, LLC, entitled “Dome Flubs, Dome Assembly Kits, and Dome Assembly Methods” CN106592762A to ![custom-character]()
entitled Space assembling type bolt-column joint;“. CN106760235A to ![custom-character]()
![custom-character]()
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entitled Kind Of Multidirectional Adjustable Curved Surface Lighting Roof Grid System;” US20170167516A1 to Paul H. Mason, entitled “Strut Connector;”. US9731773B2 to Caterpillar Inc. entitled “-Node For A Space Frame;”. DE102016010883A1 to Technische Universitätm Chemnitz Variable, entitled “Connection Element,” CN110578370A to ![custom-character]()
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entitled “Bolt Ball For Steel Structure Connection;”. US20200109549A1 to Manuel Fernando and Bethencourt Cravid entitled “Lattice Structure”; and CNI 11042318A to ![custom-character]()
, entitled “Single-Layer Aluminum Alloy Latticed Shell Box Type Modular Assembly Joint And Construction Process Thereof.”
SUMMARY OF THE INVENTION
It should be recognized that the prior art does not teach a frame structure whereby frame elements converge to transfer loads to and from a common point at a hub thereby avoiding rotational moments in the hub. The invention teaches structure and methods whereby beam loads are transferred axially to hubs. This approach is beneficial in its ability to enable a direct load transfer between load bearing members mutually terminated within a common hub. The presently described hub is an essential joining element in the construction and operation of frames of the type described and shown. Uniquely, the hub is a one piece monolithic element functional as a node within a frame structure. In practice, a hub may be a terminal point within a frame structure, or it may join two or more struts of the frame. In one aspect of the presently described apparatus, the longitudinal axes of all struts which are joined to a single common hub pass through a common point. This avoids the possibility of force moments on, or within, the hub, important for passing tensile and compressive forces along the frame without unwanted stress being applied to the frame and without generating bending or shear forces on the struts or hubs. In another aspect of the invention, the axis of each strut is coaxial with a radius of a theoretical sphere of the hub body and may be selectively positioned within a range of angular positions all the while remaining co-radial with the theoretical sphere. Of course, this accounts for the benefit described in the preceding. In another aspect of the invention, the angular range of positions of each one of the struts relative to their connected hubs may be between 45° and 90°. In another aspect of the invention, each of the fasteners may have a threaded stud or a threaded entry and may be rotatable about its radially aligned axis thereby providing a simple and quick means for securely attaching one end of a strut to the fastener wherein the strut may be adapted for threadedly engaging the fastener. In another aspect of the invention, each one of the hubs may be rotatable enabling any position within a solid angle having a cone outer surface defined by the angular range of the possible extreme positions of the fastener. The details of one or more embodiments of these concepts are set forth herein and other features, objects, and advantages of these concepts will be apparent to those of skill in the art from this writing and drawings, and from the claims.
DESCRIPTION OF THE DRAWINGS OF THE INVENTION
Embodiments of the invention are illustrated only as examples in the drawing figures accompanying this written description. Alpha-numerical call-outs are used to identify elements of the invention, wherein the same call-out refers to the same element as it may appear in various views of the figures.
FIG. 1 is a perspective view of a frame structure of the invention;
FIG. 2 is a section view of a hub thereof;
FIG. 3 is a perspective view of the hub of FIG. 2;
FIG. 4 is an elevation view thereof;
FIG. 5 is a further elevation view thereof;
FIG. 6 is an expanded partial section view of a strut-connector-hub of the invention;
FIG. 7 illustrates FIG. 6 with strut-connector-hub joined; and
FIG. 8 is a perspective view of a hub interconnected with struts of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In an embodiment of the invention, a frame structure (frame 5) is shown in FIG. 1 and comprises a plurality of struts 50 engaged with a plurality of hubs 10 making up a structure which may be quite large and may have a desired overall shape or appearance. Although not described here, frame 5 may have panels and similar structure attached and incorporated therewith forming walls, floors and other useful building features. The designer or architect of frame 5 will consider the topography of the surface on which frame 5 is to be supported as well as loads due to wind and other natural forces including potential surface movements, and also bearing loads, and stress and strain factors within frame 5 due to its own weight and to possible loads and external forces. These considerations are well-known in structural engineering practice and can be calculated using standard methods. As will be understood, hubs 10 within frame 5 are the elements to which all struts 50 attach and are therefore the “glue” which holds frame 5 together in its desired configuration. Struts 50 may be made of metal, polymer materials, resins, nanotubes, fiber reinforced composites, and other engineering materials and may be solid beams or hollow with circular, rectangular or other cross sectional shapes; see FIG. 8. Each of the two opposite ends 52 of each strut 50 may be engaged with a hub joint 10A, 10B, or 10C which are best shown in FIGS. 2 through 5. In this description further reference to hub joints shall be designated by “10x” which shall mean one or more than one such hub joints. Each one of hubs 10 comprises a monolithic body with at least two, but possibly more than two, integral hub joints 10x. In order to provide maximum flexibility in placement of struts 50 within frame 5, it is desirable that hubs 10 be able to accommodate (receive and connect with) struts 50 arriving from a wide range of directions. This permits the total number of components (struts, hubs) to be minimized, thus minimizing costs. This, in turn, requires that hub joints 10x have the largest number and greatest range of possible angular positions on hubs 10. In order to accommodate struts 50 that are near or adjacent to one another at any hub 10, it is necessary to use length L, as shown in FIG. 2, as a design parameter and as a means of providing strut-to-strut clearance at any given hub 10. Further, it should be understood that by using a minimum possible length L for all hub joints 10x, hub manufacturing time and material usage, and overall weight and cost of frame 5 are minimized. This can be of significant commercial benefit. Now, referring to FIGS. 2-5, we see in FIG. 2 that in hub 10 the direction of each hub joint 10x is defined by its vector 12. That being the case, then it is obvious that each two adjacent vectors 12 define a plane in 3-space and if the sizes of struts 50, hardware elements 40, 42 and sleeve 20 (see FIGS. 6 and 7) are known, the minimal length L to afford clearance between adjacent struts 50 may be determined by graphical or algebraic methods in order to assure adjacency clearance. Each one of hub joints 10x is adapted, in a manner to be described, for engaging an end 52 of one of struts 50 as shown in FIGS. 6 and 7. Axes of each one of hub joints 10x mutually converge on a common point 14 as shown in FIG. 2. With respect to each hub 10, its hub joints 10x are preferably positioned such that axes 12 all converge on common point 14. Therefore, force moments on hubs 10 are avoided which assures that hubs 10 do not tend to rotate which could damage the components as well as frame 5 itself. At least one of hub joints 10x may be a tubular projection of the monolithic body of hub 10. Struts 50 may be of disparate sizes and hub joints 10x may likewise be of disparate sizes corresponding to the sizes of struts 50, see, for instance, FIG. 2. Hubs 10 are preferably fabricated by 3D printing methods and may be made of hard polymers or metals. They can also be produced by processes such as molding, machining and stamping. Struts 50 may be linear in form with two opposing ends 52 wherein each of these ends 52 may be joined with one of hub joints 10x by a tubular sleeve 20 as shown in FIGS. 6 and 7. As shown tubular sleeves 20 may be fastened to one of hub joints 10x by an axially oriented fastener such as bolt 30 and to strut 50 by a transaxially oriented fastener 40 and nut 42. This is considered to be a novel arrangement but it will be possible for those of skill in the mechanical arts to arrange different attachment schemes. In an embodiment of the invention, a method of producing frame 5 may include engaging a plurality of struts 50 with a plurality of hubs 10 in a manner shown in FIGS. 6 and 7. This may involve forming each of hubs 10 as a monolithic body having plural hub joints 10x and adapting each one of hub joints 10x for engaging an end 52 of one of struts 50 by using a tubular sleeve 20. Hub joints 10x may be positioned so that axes 12 are mutually convergent on point 14 as shown in FIG. 2. The method may include producing hub joints 10x as tubular projections integral to the monolithic body of hub 10. The struts 50 of frame 5 may be produced in sizes, of materials, and of cross-sectional design as required by their load carrying functions.
Embodiments of the subject apparatus and method of this invention have been described herein. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and understanding of this disclosure. Accordingly, other embodiments and approaches are within the scope of the following claims.
Patent Application
20230250628
