Adjusting ring for electrical floor boxes

Claim 1

For use in conjunctIon with an electrical floor box element which includes a threaded handhole in the top of the box element and which is mountable entirely below the surface of a floor, a two-part adjusting ring assembly, one part comprising an annular collar in the form of a generally straight cylinder terminating in upper and lower generally vertically aligned ends, the lower end region being threaded for engagement with the threads of the handhole, the upper end region embodying peripheral first flange extending radially outward from the external wall of the cylinder and providing a thrust shoulder on its lower surface and a generally flat tread on its upper surface, a second flange extending radially inward from the internal wall of the cylinder and axially intermediate the threaded region and the first flange and providing an annular shelf for reception of finishing and fixture mounting elements, the collar as defined being an integral structure, the second part comprising a separate generally flat thin annular ring having an internal annular notch providing a horizontal seat coincident with and adapted for engagement by the thrust shoulder with a rotatable slip action, the annular ring embodying a lower surface adapted to rest upon a floor and an upper tread surface forming a continuation of the tread surface of the first flange, whereby the collar may be rotated to threadedly advance the collar downwardly relative to the handhole of the box element, and the engagement of the seat of the annular ring by the thrust shoulder provides an axial thrust to clamp down the annular ring on the floor surface or covering without appreciable rotation of such ring, the axial dimensions of the first flange and the internal notch of the ring corresponding so that when the collar and annular ring are fully assembled with the box element the junction of the tread surface of the first flange of the collar and the tread surface of the annular ring lie in the same general horizontal plane.