Unitary hubs for domes or spheres

Abstract

A unitary hub includes a central body and two or more tubular cylindrical prongs that can be used in conjunction with two or more struts to construct a dome or a sphere, such as a geodesic dome. The prongs have a first segment and a second segment that are disposed at an angle. The first segment has a first inner diameter and the second segment has a second inner diameter thereby creating a recess for the struts to be positioned easily and accurately within the prongs. The central body is formed from joining the two or more prongs disposed around an axial axis through a center of the central body. The central body has a top and bottom side with a spherically concaved section having a curvature. The struts may be tubular and cylindrical and can be inserted into the prongs or over the prongs.

What is claimed is: 
     
         1 . A unitary hub for a dome, comprising:
 (a) two or more tubular circular cylindrical prongs each comprising a first straight segment and a second straight segment;   wherein the first straight segment is tilted with respect to the second straight segment thereby making a segment angle;   wherein the first straight segment has a first inner diameter and a first outer diameter and the second straight segment has a second inner diameter and a second outer diameter;   (b) a central body formed from joining the two or more tubular circular cylindrical prongs disposed around an axial axis through a center of the central body;   wherein the hub comprises a top side and a bottom side; and   wherein the surface of the bottom side comprises a spherically concaved section having a curvature.   
     
     
         2 . The hub of  claim 1 , wherein a length of the first straight segment is equal to 1.0 inches. 
     
     
         3 . The hub of  claim 1 , wherein the segment angle is equal to 12 degrees. 
     
     
         4 . The hub of  claim 1 , wherein the first inner diameter is equal to 1.33 inches. 
     
     
         5 . The hub of  claim 1 , wherein the second inner diameter is equal to 1.00 inches. 
     
     
         6 . The hub of  claim 1 , wherein each prong further comprises a tapered hole. 
     
     
         7 . The hub of  claim 1 , wherein an outer diameter of the first straight segment is equal to 1.60 inches and outer diameter of the second straight segment is equal to 1.70 inches. 
     
     
         8 . The hub of  claim 1 , wherein the hub comprises 3 prongs disposed at 0 degrees, 120 degrees, and 240 degrees, measured from a transverse axis perpendicular to the axial axis and passing through the center of the central body. 
     
     
         9 . The hub of  claim 1 , wherein the hub comprises 4 prongs disposed at 0 degrees, 60 degrees, 120 degrees, and 180 degrees, measured from a transverse axis perpendicular to the axial axis and passing, through the center of the central body. 
     
     
         10 . The hub of  claim 1 , wherein the hub comprises 5 prongs disposed at 0 degrees, 72 degrees, 144 degrees, 216 degrees, and 288 degrees, measured from a transverse axis perpendicular to the axial axis and passing through the center of the central body. 
     
     
         11 . The hub of  claim 1 , wherein the hub comprises 6 prongs disposed at 0 degrees, 60 degrees, 120 degrees, 180 degrees, 240 degrees, and 300 degrees, measured from a transverse axis perpendicular to the axial axis and passing through the center of the central body. 
     
     
         12 . The hub of  claim 1 , wherein the top side comprises a circular cylindrical protrusion. 
     
     
         13 . The hub of  claim 1 , wherein a radius of curvature of the spherically concaved section is equal to 120 inches. 
     
     
         14 . A hub-strut assembly comprising the hub of  claim 1  and two or more struts coupled with the two or more prongs. 
     
     
         15 . The hub-strut assembly of  claim 14 , wherein each of the two or more struts comprise a tubular circular cylindrical pipe. 
     
     
         16 . The hub-strut assembly of  claim 15 , wherein at least one of the tubular circular cylindrical pipes is inserted into the first straight segment of one of the two or more prongs. 
     
     
         17 . The hub-strut assembly of  claim 15 , wherein the first straight segment of at least one of the two or more prongs is inserted into one of the tubular circular cylindrical pipes. 
     
     
         18 . A dome assembly comprising a plurality of the hub-strut assembly of  claim 14 . 
     
     
         19 . A method of constructing a unitary hub for a dome, comprising:
 (a) providing two or more tubular circular cylindrical prongs each comprising a first straight segment and a second straight segment;   wherein the first straight segment is tilted with respect to the second straight segment thereby making a segment angle;   wherein the first straight segment has a first inner diameter and a first outer diameter and the second straight segment has a second inner diameter and a second outer diameter; and   (b) joining the two or more tubular circular cylindrical prongs to form a central body, said two or more tubular circular cylindrical prongs disposed around an axial axis through a center of the central body:   wherein the hub comprises a top side and a bottom side; and   wherein the surface of the bottom side comprises a spherically concaved section having a curvature.   
     
     
         20 . A method of assembling a dome, comprising:
 (a) providing a plurality of unitary hubs, each unitary hub comprising:   (i) two or more tubular circular cylindrical prongs each comprising a first straight segment and a second straight segment;   wherein the first straight segment is tilted with respect to the second straight segment thereby making a segment angle;   wherein the first straight segment has a first inner diameter and a first outer diameter and the second straight segment has a second inner diameter and a second outer diameter; and   (ii) a central body formed from joining the two or more tubular circular cylindrical prongs disposed around an axial axis through a center of the central body;   wherein the hub comprises a top side and a bottom side; and   wherein the surface of the bottom side comprises a spherically concaved section having a curvature;   (b) providing a plurality of struts coupled with the two or more prongs of each of the unitary hubs.