초록 ▼

A plastic duct section is equipped with integral connections on its ends. Each duct has indicia along its running length to facilitate cutting of the duct to a desired length. In one embodiment, the indicia may take the form of equally spaced circumferential ribs spaced along the length of the duct.

A plastic duct section is equipped with integral connections on its ends. Each duct has indicia along its running length to facilitate cutting of the duct to a desired length. In one embodiment, the indicia may take the form of equally spaced circumferential ribs spaced along the length of the duct. These ribs are engaged by sets of fingers extending toward each other from concentric walls spaced to receive the straight end of an adjacent duct section. The innermost end of the concentric walls is equipped with a layer of insulative material to enable sealing engagement between duct sections significantly reducing pressure loss. Attached straps permit duct sections to be easily suspended between adjacent joists. A floor-mounted elbow boot is equipped with a removable plastic cover to prevent dust, dirt and debris from accumulating in the installed heating duct during finish construction of the building.

대표청구항 ▼

[I claim:] [1.]a) a section of hollow duct having a first lateral geometric cross section and indicia of length provided along an outer surface portion of said hollow duct for facilitating cutting of said duct to a particular length,b) a connector for engaging a first end of said section of hollow d

[I claim:] [1.]a) a section of hollow duct having a first lateral geometric cross section and indicia of length provided along an outer surface portion of said hollow duct for facilitating cutting of said duct to a particular length,b) a connector for engaging a first end of said section of hollow duct having a second lateral geometric cross section identical to said first lateral geometric cross section and a first outer portion which has a C-shaped axial cross section formed by first, second and third inwardly directed surfaces, said first and third surfaces extending generally parallel to each other forming opposing parallel surfaces and said second surface interconnecting said first and third surfaces, a plurality of gripping fingers extending inwardly from each of said first and third surfaces toward said opposing parallel surface, said gripping fingers including a first group extending inwardly from said first surface toward said third surface and a second group extending inwardly from said third surface toward said first surface said first and second groups of fingers overlapping one another;whereby a first section of hollow duct may be connected to a second section of hollow duct by inserting said first end thereof into said connector having said C-shaped axial cross section, said inwardly extending fingers of said connector engaging inner and outer surfaces of said first section and restricting removal of said first end from said connector.