Patent ID: 7155874
Filing Date: 2007-01-02
Classification: E04B,E04C

Abstract:
1. A hollow elongated tubular structure comprising: a first elongated C-shaped channel having a central, main section and two integral end sections, and integral, inwardly extending flanges only along the length of said main section, a second elongated C-shaped channel having a central, main portion and two integral end portions with flanges only along the length of said main portion, said second channel being of the same configuration as said first elongated C-shaped channel, and a holding member located in each channel end section and fixedly connecting said first and second channels together so that the flanges located in the main section of said first channel contact the flanges located in the main section of said second C-shaped channel, wherein the flanges of said first and second C-shaped channels have an inward bend and the surfaces of the flanges coming in contact with each other are planar and form an airtight seal along the length thereof.