Non-rigid mechanical coupling for a fire-rated feed-through fitting and method of making

Claim 1

In a fire-rated feed-through fitting for transferring insulated wires through a conduit disposed in a circular opening formed in a floor of a building by which electrical power and other signals are transmitted from a source located at one face of said floor via said wires, through said fitting mounted in said opening to respective circuits connected to said wires and mounted on a head assembly disposed on the opposite face of said floor, an improved non-rigid joint for loosely mechanically coupling said head assembly to said conduit, comprising: at least one conduit flange having a peripheral portion coupled to said head assembly, said peripheral portion circumscribing an aperture having an outline shaped in correspondence to the cross-sectional dimensions of said conduit, but larger than the conduit, and plural tabs integrally formed with said peripheral portion and extending radially inwardly into said aperture at approximately common intervals around the circumference of said aperture; and said conduit having a plurality of slots formed in the vicinity of one end of the conduit, said slots spaced substantially in a common transverse plane at intervals corresponding to the spacing intervals of said conduit flange tabs; and wherein said tabs extend into said conduit slots and are loosely retained therein, holding said conduit and head in assembled relationship via said conduit flange, with the peripheral portion of the flange held spaced from the conduit by limited spaced contact between the tabs and slots, thus significantly reducing thermal conductivity between the conduit, flange and head assembly.