As previously reported by AppleInsider, Apple first filed for its "Glass building panel and building made therefrom" patent in 2011. The company was finally granted ownership rights to the invention on Tuesday.
Apple's U.S. Patent No. 8,544,217 not only covers the design of the cylinder, but more specifically the type of glass and construction methods used to erect such a structure.
Like the flagship Fifth Avenue Apple Store in New York, the Shanghai cylinder is made almost entirely out of huge monolithic glass slabs, with only connecting joints fashioned out of metal. The Chinese build is more complex, however, as the specifications required the glass pieces required be curved to form arcs. These panels were then joined to create a circle and ultimately a cylinder.
Apple notes that conventional glass laminate technology at the time was insufficient to create panels that could withstand the structural requirements for supporting loads and forces over long spans. The lack of structural support prevented architects from crafting large buildings out of glass, especially those with curved walls.
Laminated glass profile.
Instead of using conventional methods, Apple employed unique glass fins and beams with integrated metal fittings to create a solid building. Laminating the fittings directly into the glass itself increases structural rigidity of the combined panels and provides for an easier build.
Key to the building's strength is a central cylindrical support made of curved glass that is connected to the large outer glass panels via a set of glass beams. Finally, a glass roof composed of multiple panels is supported by a number of glass fins that run from the top of the structure to the floor.
Illustration of glass roof panels (310), cylindrical support (550) and beams (510, 520, 530).
The patent goes into more detail regarding the specifications of each glass piece and offers a brief overview of how the cylinder should be constructed for optimal results.
Apple's glass cylinder patent credits David Andreini, Karl Backus, Jon F. Cooksey, Tim Eliassen, Scott David Hazard, Holger Krueger, Peter Lenk, James O'Callaghan and Yutang Zhang as its inventors. Also cited in the document is a U.S. patent for glass laminate support structures, invented in part by Apple cofounder Steve Jobs.