Abstract: A circular gasket for sealing the opening between the exterior of a sewer pipe and the interior periphery of an opening in a manhole, in which greater sealing pressure is provided by using a plurality of longitudinal openings extending entirely around the gasket through the head portion thereof which contacts the sewer pipe.

Abstract: An improved seal for closing the space between a pipe and the wall of an opening through which it passes, using a linear extrusion of elastomeric material, of predetermined length to form a gasket. The extrusion has a hollow, pear-shaped head formed integrally with a T-shaped anchoring flange. It is curled into the form of a right cylinder, and its mating ends are vulcanized together. The pear-shaped portion is deflected radially inwardly and the T-shaped anchoring flange outwardly, the latter being then embedded in concrete used to wall the opening for the pipe. The pear-shaped portion is free in space and provides a pneumatic cushion for the pipe.

Abstract: A gasket for resiliently supporting a sewer pipe in a manhole opening, while sealing the opening against fluid flow, which gasket is a molded annulus of elastomeric material having a peripheral flange of substantial width and thickness connected by a radially extending web to an inner concentric rib of greater width than said web, and adapted to be embedded in concrete to its radially inward face, said rib having an integral circular skirt extending inwardly therefrom in a non-radial direction, and united at its rim with a second circular skirt oriented thereto at a reverse angle, said second skirt merging throughout its periphery into an O-ring of slightly smaller diameter than the diameter of the sewer pipe it is adapted to surround.

Abstract: Pockets, defined by molded plastic shells, are embedded in a massive concrete article. Lifting cables have rods to fit into the pockets. The shells which define these pockets are injection-molded to provide a lateral spline to pass a key formed on the lifting rod, and also have a parti-cylindrical end housing, closed by a snap-fitted cover plate, within which housing the key rotates to lock the rod in the socket when lift is applied to the rod.

Abstract: An improved seal for closing the space between a pipe and the wall of an opening through which it passes, using a linear extrusion of elastomeric material, of predetermined length to form a gasket. The extrusion has a hollow, pear-shaped head formed integrally with a T-shaped anchoring flange. It is curled into the form of a right cylinder, and its mating ends are vulcanized together. The pear-shaped portion is deflected radially inwardly and the T-shaped anchoring flange outwardly, the latter being then embedded in concrete used to wall the opening for the pipe. The pear-shaped portion is free in space and provides a pneumatic cushion for the pipe.

Abstract: Vertically aligned manhole sections are assembled by setting one section upon the other whereby cooperating male and female ends are mated to form a watertight joint. The male and female ends are each provided with a diagonally aligned surface adjoining horizontally aligned load bearing surfaces. A shoulder is formed in the diagonally aligned surface of each male end to receive an annular D-shaped gasket mounted therein under tension. The gasket is compressed between the male and female diagonally aligned surfaces so that when one load bearing surface of the upper section is fully bottomed on the cooperating surface of the lower section, the gasket is fully compressed, with the weight of the upper sections serving to aid in compressing the gasket.

Abstract: Method and apparatus for forming steps in manhole structures. Manhole assembly is comprised of pre-cast concrete sections. Each such section is formed in an appropriate mold typically comprised of inner and outer mold shells. The inner shell is provided with pairs of openings arranged in a predetermined fashion. Plastic core members are snap fittingly inserted into the openings and are provided with resilient pairs of flanges which cooperate with the marginal edges of each opening to retain the core in proper position and alignment. The concrete is placed in the mold. One set and cured, the section is removed from the mold. The plastic core members are snapped free from their locked position with the mold inner shell and remain as an integral part of the cured section. U-shaped stepped sections are force fittingly inserted into the cores which serve to retain each step member in position.