Abstract
A plurality of hubs are joined to frame struts thereby forming a space frame structure, wherein the hubs have monolithic bodies with protruding joints adapted for receiving and joining with the frame struts using tubular sleeves. Axes of the joints are aligned to converge at a common point to avoid rotational moment forces on the hubs. The hubs are preferably fabricated by a 3D printing method in a structural material. In a method of the invention, the struts, joint diameters and joint lengths are sized and positioned to avoid interference between adjacent struts.
Claims
1. A frame structure comprising: a plurality of struts engaged with a plurality of hubs; each of said hubs comprising a monolithic body with at least two integral hub joints integrally formed with said monolithic body; wherein each one of said hub joints is adapted for engaging an end of one of said struts; and wherein axes of said hub joints mutually converge.
2. The frame structure of claim 1 wherein at least one of said hub joints is an integral tubular projection extensive from said monolithic body.
3. The frame structure of claim 1 wherein said struts are of disparate sizes.
4. The frame structure of claim 3 wherein said hub joints are of disparate sizes corresponding to said disparate sizes of said struts.
5. The frame structure of claim 1 wherein at least one of said hubs is a product of a 3D printing method.
6. The frame structure of claim 1 wherein said end of said one of said struts is joined with one of said hub joints by a tubular sleeve.
7. The frame structure of claim 6 wherein said tubular sleeve is fastened to said one of said hub joints by an axially oriented fastener and to said strut by a transaxially oriented fastener.
8. A hub for integration into a frame structure said hub comprising: a monolithic body with at least two integral hub joints; wherein each one of said hub joints is adapted for engaging an end of a strut of said frame structure; and wherein axes of said hub joints mutually converge.
9. The hub of claim 8 Wherein at least one of said hub joints is a tubular projection relative to said monolithic body.
10. The hub of claim 9 wherein said hub joints are of disparate sizes.
11. The hub of claim 10 wherein said hub is a product of a 3D printing method.
12. A method of producing a frame structure wherein said method comprises: engaging a plurality of struts with a plurality of hubs; forming each one of said hubs into a monolithic body having at least two integral hub joints; adapting each one of said hub joints for engaging an end of one of said struts; and positioning said hub joints wherein axes of said hub joints mutually converge.
13. The method of claim 12 wherein said hub joints are produced as tubular projections of said monolithic body and said tubular projections are minimized in length.
14. The method of claim 13 wherein said struts are produced with disparate sizes.
15. The method of claim 14 wherein said hub joints are produced with disparate sizes corresponding to said disparate sizes of said struts.
16. The method of claim 12 wherein at least one of said hubs is produced by a 3D printing method.
17. The method of claim 12 wherein a tubular sleeve is positioned for joining said end of said one of said struts with said one of said hub joints.
18. The method of claim 17 wherein an axially oriented fastener is positioned for joining said tubular sleeve to said one of said hub joints.
19. The method of claim 17 wherein a transaxially oriented fastener is positioned for joining said tubular sleeve to said one of said struts.
Description
DESCRIPTION OF THE DRAWINGS OF THE INVENTION
[0005] 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.
[0006] FIG. 1 is a perspective view of a frame structure of the invention;
[0007] FIG. 2 is a section view of a hub thereof;
[0008] FIG. 3 is a perspective view of the hub of FIG. 2;
[0009] FIG. 4 is an elevation view thereof;
[0010] FIG. 5 is a further elevation view thereof;
[0011] FIG. 6 is an expanded partial section view of a strut-connector-hub of the invention;
[0012] FIG. 7 illustrates FIG. 6 with strut-connector-hub joined; and
[0013] FIG. 8 is a perspective view of a hub interconnected with struts of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] 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.
[0015] 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.
