Duct coupler with hinge interconnected locking rings

A coupler for joining and sealing between adjacent ends of two sections of duct of the type having an elongated duct body with a first outside dimension and at least one increased dimension portion with a second outside dimension, said coupler comprising:

• a body having a longitudinal passageway therethrough, said passageway being sized to accommodate the first outside dimension portion of said duct sections;
• flexible means at the two longitudinally spaced ends of said body for flexing outwardly sufficiently to accommodate the passage therethrough of said increased dimension portion of said duct sections;
• a pair of locking rings disposed around the outside of said coupler body and slidable longitudinally thereof between engaged and disengaged positions;
• hinge means interconnecting said locking rings for adjusting said locking rings between engaged and disengaged positions;
• and
• sealing means in said longitudinal passageway for sealing between said coupler and said duct sections,
• whereby, with said locking rings disengaged, said adjacent ends of said two duct sections can be inserted into opposed ends of said longitudinal passageway until the increased dimension portions of said duct sections have passed through said flexible means, and engaged said sealing means, after which said locking rings can be engaged, preventing said ends of said duct sections from being withdrawn from said duct coupler.