Hanger assembly

Claim 1

An expansible load-bearing junction box hanger assembly adapted for installation from beneath the ceiling and through a junction box opening in the ceiling, including a first wall and a second wall spaced from said first wall, said first and said second walls having a plurality of spike protrusions to engage two spaced adjoining ceiling joists; an elongated linearly expanding brace means which is aligned with and connected between said first and said second walls, said brace means readily expanding in length to force said first and said second walls to contact and engage their respective ceiling joists, said brace means including a tubular member rotatably mounted to said first wall, a threaded rod member threadedly and telescopically connected to said tubular member, one end of said threaded rod member being in fixed non-rotative engagement with said second wall, said first and said second walls supporting said brace means in a direction substantially parallel to the plane of the ceiling; and a junction box connecting means to rigidly connect a junction box of a heavy load to the central section of said brace means; and improvements, which comprise: each of said first and said second walls has a receiving groove adjacent to said spike protrusions; said hanger assembly further comprising an alarm device, a cell means, and a switching means including a contact switch disposed in each said receiving groove and actuated when said first and said second walls fully engage their respective ceiling joists, said switching means electrically connecting said alarm device to said cell means to operate said alarm device when said switching means is actuated, thereby indicating that said hanger assembly has fully engaged said ceiling joists.