Sub-dividing secondary support grid for a ceiling fixture

Claim 1

A sub-dividing secondary support grid support a ceiling fixture such as a light or the like in a larger opening defined by a plurality of primary ceiling grid structural members, comprising four substantially identical, elongate, secondary structural members interlocked with one another in angular relationship substantially in the shape of a pinwheel with one end of each of the elongate secondary structural members projecting laterally beyond another elongate secondary structural member with which it in interlocked, said interlocked secondary structural members defining a rectangular secondary opening therebetween, each elongate member having an opening therethrough adjacent said one end thereof and an axially projecting tab on the other end thereof, the tab on each secondary structural member received through the opening in an adjacent secondary structural member and bent over tO secure all of the secondary structural members together in said pinwheel shape, the said one ends of the secondary structural members supported on said primary grid structural members to space said secondary opening substantially centered in said larger opening, and a ceiling fixture supported on said secondary support grid in said secondary opening, the connection of said other end of each secondary structural member with an adjacent secondary structural member near said one end thereof resulting in the load carried by the secondary structural members being concentrated near the connection thereof with the primary structural members and thus reducing the bending moment on the secondary support grid.