TODAY’S PATENT- ROOF DRAIN ASSEMBLY
Today’s patent was invented by Robert W. Mason and Harvey C. Roberston on July 26, 1988, bearing patent no. US4759163A.
The present invention relates to the roof drain assembly. It comprises a roof structure that has an open therethrough with a drainage duct extending downwardly through the opening, and a re-roofing structure which includes a layer of insulation and which is disposed over the existing roof structure with an opening through the re-roofing structure in alignment with the opening through the existing roof structure. A drain extension pipe extends through the opening in the re-roofing structure and into the upper-end portion of the drainage duct.
The portion of the drain extension pipe within the drainage duct is of a non-resiliently deformable material like lead, and this non-resiliently deformable portion of the drain extension pipe is outwardly mechanically deformed against the drainage duct to provide a substantially water-tight seal therebetween. In use, an outer tube to which the upper plate is secured is prevented from turning, And an inner shaft which is screw-threadedly disposed through the upper plate and on the lower end of which the lower plate is mounted is turned in the appropriate direction to cause the lower plate to move towards the upper plate with resultant axial compression and outward expansion of the resiliently deformable annulus against the non-resiliently deformable portion of the drain extension pipe.