Sealing plugs or closures

Claim 1

A sealing plug and cap for the end of a thin wall pipe comprising a semihard rubberlike material, whether of natural or synthetic rubber, polychloroprene, or the like, with said plug being a large diameter relatively thick disc, of dimensions illustratively given as about 5 inches in diameter and 1 1/2 inches in thickness; with said disc having flat upper and lower surfaces and a peripheral surface; for fitting inside the pipe end; said peripheral surface having a series of parallel ribs; for entering the pipe end and abutting the interior of the pipe to seal it; with the upper ribs tapered and undercut to provide flexing sealing fins at their lower edges; with the lowermost rib or flange being square and untapered, and of a diameter greater than that of the other ribs of the plug so as to seal and cap the edge of the pipe and remain outside the pipe end; with such cap rib having an outside diameter substantially equal to the outside diameter of the pipe end so as to cap it, without projecting laterally beyond the pipe.