|
|
||
|
|
|
|
From:
http://www.rainharvest.com/rainmaster-corrugated-steel-tank-systems.asp
Multi-wall cylindrical structure, method of making such structure, and apparatus for carrying out such method
United States Patent 6955780
ABSTRACT: An elongated composite tube made up of an inner tube 42 and an outer tube 44 (see FIG. 3) with a plurality of elongated helical ribs disposed between the inner tube and the outer tube in a supporting relationship to both. A slinky like toy made from the composite tube is also disclosed, as is a method of making both.
Page 75 / 180