Mounting bar system for attaching interior fittings and electric wiring to a concrete ceiling

Claim 1

A dual-purpose electrical distribution/mechanical support system comprising a building structure having a ceiling fabricated of concrete, at least one elongated mounting bar fixedly embedded in said concrete ceiling, said bar having a substantially U-shaped cross section comprising a pair of substantially parallel sides the lower edges of which are spaced from one another to define an elongated opening therebetween located substantially flush with the interior surface of said ceiling, the exteriors of said parallel sides being substantially completely bounded by the concrete of said ceiling to prevent said sides from spreading apart when outwardly directed forces are exerted on the interiors of said sides, a plurality of electrical conductors supported along the interior surfaces of said parallel sides above and spaced from said opening, the lower edges of said parallel sides defining a pair of inwardly extending support flanges adjacent said ceiling surface and below said conductors, at least one removable electrical plug extending through said opening for making electrical contact with said conductors to provide a source of electrical energization within said building structure, and suspension means removably supported by said flanges in spaced relation to said electrical plug and in non-contacting, spaced relation to said conductors to provide support for a mechanical fixture which is suspended within said building structure from said ceiling mounted bar, said suspension means comprising a strip-shaped member having a pair of opposing edges which engage said pair of flanges respectively adjacent said opening, said member being shaped between its edges to bulge away from said opening toward the interior of said U-shaped bar whereby forces exerted downwardly from the bulged portion of said member toward the interior of said building structure impose forces on the interior sides of said mounting bar in directions tending to spread said sides apart, said inwardly bulging portion of said member having at least one aperture therein, and a support element remvovably attached to said member at said aperture and extending through said opening toward the interior of said building structure for attachment to said mechanical fixture, said support element comprising a rod extending throUgh said aperture and having a shaped head at its upper end for attaching said rod to said member.