US Patent 9303812 Adjustable hanger bar for luminaires

A hanger bar assembly includes a first hanger bar member that includes a first rail segment. The first hanger bar member also includes a first channel segment that includes a first channel. The first hanger bar member also includes a first transitional middle segment extending between the first rail segment and the first channel segment. The hanger bar assembly further includes a second hanger bar member that includes a second rail segment. The second rail segment is positioned in the first channel of the first channel segment. The second hanger bar member further includes a second channel segment that includes a second channel. The first rail segment is positioned in the second channel. The second hanger bar member also includes a second transitional middle segment extending between the second rail segment and the second channel segment.