Hollow body outlet for under-floor and under-plaster installations

Claim 1

A hollow body for insertion into an outlet opening for underfloor and under-plaster installations formed in hardened material, said hollow body including: a first clamping element and a second clamping element having coaxial central openings, said elements having peripheral inclined surfaces facing each other and converging inwardly toward their axis and adapted to be pressed toward each other, a split tightening element of less diameter than said outlet opening arranged between said first and second clamping elements and having inclined surfaces complementary to and engaging said first inclined surfaces and expandable outwardly of said first and second clamping elements to engage the inner wall of said outlet opening, flanges on the inner peripheries of said elements, and means operatively connected to said flanges on said clamping elements and spaced circumferentially and operable to move said clamping elements toward each other to engage said first inclined surfaces with the inclined surfaces on said tightening element and thereby press said clamping elements to expand said tightening element into frictional engagement with the inner wall of said outlet, and a mounting element on said hollow body to extend across said outlet, inward extensions on the flange of said clamping element farthest from said mounting element, and fasteners connecting said mounting element to said extensions.