METHOD AND APPARATUS FOR PROVIDING WATERTIGHT SEAL FOR MANHOLE PIPE CONNECTION INCLUDING NOVEL FOLDABLE GASKET AND CLEATED EXPANSION APPARATUS COOPERATING WITH PLURAL RECESSES IN THE GASKET CLAMPING BAND

摘要

A resilient gasket is provided herein having an outer flangepositioned within a manhole opening and held by a compressionband. The gasket has a central opening with an enlarged beadedperiphery to encircle a pipe. A tapered intermediate section isjoined to the outer flange and the beaded periphery. Theintermediate section folds after insertion and clamps in anopening to form diagonally-aligned annular portions defining aV-shaped yieldable gasket to maintain a watertight seal betweenopening and pipe, even when misaligned. A strap encircling thegasket next to the beaded periphery enhances the watertight sealbetween gasket and pipe. The clamping band has free ends whichcooperate with projections of a piston cylinder assembly. Theclamping band is formed of material impervious to the surroundingenvironment. The expansion assembly includes the piston cylinderassembly which cooperates with an hydraulic jack and ispositioned with its projections against the free ends of theclamping band to expand the clamping band into a locked positionagainst the gasket flange and to apply a force directly upon theclamping band to insure proper positioning and locking of theclamping band. The hydraulic jack may also include a swingablemember having a free end which moves along a curved path tofollow the movement of the clamping band as it expands. Theinitial configuration of the gasket expedites the insertion,expansion and locking of the clamping band. A cooperating groovereceives a projection, the groove and projection being adjacentat opposite ends of the clamping band to prevent relative axialmovement of the clamping band ends as it is expanded.