Abstract: An elastomeric seal having substantially hollow body having a polygonal cross section formed by a bottom wall, a pair of opposed spaced side walls, a top wall and a plurality of internal supporting struts symmetrically arranged about the center of the polygonal cross section. The top wall is formed of a pair of arms extending in a V to each other, the apex of which lies along the center line between the side walls. The side walls are themselves bent inwardly intermediate their ends to extend perpendicular to the respective arms of the top walls. Compression of the parallel side walls, toward each other, causes the inwardly bent portions of the side walls to rotate outwardly resulting in a raising of the apex of the top wall so that the top wall assumes a flat configuration.

Abstract: A comparatively wide sealing strip extruded of elastomeric material that in practice is used for sealing expansion grooves in bridges or the like, having a conventional arrangement of external functional walls, and in which the internal support walls that are provided to prevent collapse in the external walls while the elastomeric construction material is curing, cooperate to form a centrally located hexagonally shaped wall arrangement that flattens out when the seal is subjected to external compressive forces, and in this way enables the seal to offer an optimum minimum resistance to change to a diminished size.