Emergency seal.

摘要

A safety seal for a shaft (14) passing through a housing. The seal is normally maintained in a non-sealing relationship to the shaft, but may be actuated during emergency conditions by levers. The seal includes an annular, split housing (20a, 20b) having a radially extending compartment (16) which contains at least two seal members (34, 34) which are held together by a bias to define a seal annulus. The seal members (34, 34) are radially contracted into sealing engagement and expanded to a non-sealing position by cams (44) or levers (60) mounted in the seal members.