EXPANSION RING ASSEMBLY WITH REMOVABLE DRIVE MECHANISM

An expansion ring assembly for sealing a gasket within an opening in the wa ll of a structure, the assembly including a drive mechanism having a pair of block members each having a threaded bore, and a bolt having oppositely threaded ends respectively threaded within the bores. The block members are removably engaged with respective en ds of the expansion ring. An oversleeve is disposed in overlapping relationship with t he expansion ring ends, and the expansion ring ends and the oversleeve include cooperatin g ratcheting structures. Rotation of the bolt of the drive mechanism in a first direction causes the block members to move outwardly along the bolt to expand the expansion ring and concurrently sequentially engage the ratcheting structures of the expansion ring ends and the oversleeve. Once the expansion ring is expanded to a desired extent, the bolt of the dri ve mechanism may be rotated in a second direction opposite the first direction to move the block members inwardly along the bolt and allow disengagement of the block members from th e expansion ring ends and removal of the drive mechanism. The expansion ring ends are maintained in their expanded condition by the engagement of the ratcheting structures of t he expansion ring ends and the oversleeve. In another embodiment, overlapping endsof the expansion ring have ratcheting structure therebetween, and are driven apart by the removabl e the drive mechanism, wherein the oversleeve member is eliminated.