1. Summary of the Invention
The present invention relates to an improved plastic coupling which is secured in place in a cored or drilled hole in a concrete floor or wall. In particular, the present invention relates to an improved coupling which is secured in place in the hole by a plastic to concrete adhesive.
2. Prior Art
The prior art has described cast-in-place plastic couplings for use in building construction. These are particularly shown in U.S. Pat. Nos. 4,261,598 to Cornwall and 4,453,354 and 4,313,286 to Harbeke. These couplings have projections or ridges on the outside which hold the coupling in place. Fluid concrete is poured around the coupling and then the concrete is allowed to set to form a floor or a wall supporting the coupling. The resulting cast-in-place coupling provides a very good conduit between pipes mounted in the coupling on either side of the floor or wall.
The problem faced by the prior art is that during construction of a building after the wall or floor has been poured and set, a need arises for a coupling mounted through the concrete floor or wall which can function like the cast-in-place coupling. A cast-in-place coupling can be secured in place by providing a large opening in the wall or floor where concrete is then re-poured as a patch around the coupling. The problem is that the coupling and/or patch can work loose. The prior art has not provided an effective means for securing a plastic coupling through a pre-formed floor or wall in a building.
USPTO Backgrounds
USPTO Backgrounds