Patent ID: 6979002
Filing Date: 2005-12-27
Classification: F16J,Y10S

Abstract:
1. A seal assembly for sealing a shaft within a housing, comprising: a) a plurality of resilient seal members radially biased towards said shaft and mounted with respect to said housing, at least one of said resilient seal members disposed to assume a preloaded condition out of contact with said shaft and a loaded condition in sealing contact with said shaft; b) a barrier member in axial alignment with said shaft and defining a clearance space between said shaft and said at least one resilient seal member in its preloaded condition, said barrier member physically interposed between said shaft and said at least one resilient seal member in its preloaded condition, said barrier member mounted for movement relative to said shaft; c) wherein said at least one resilient seal member deploys from said preloaded condition to said loaded condition in response to movement of said barrier member relative to said shaft, and wherein said movement effects sealing engagement between said at least one resilient seal member and said shaft; d) said barrier member being mounted for axial movement relative to said shaft; e) said plurality of resilient seal members including first and second resilient seal members configured to assume preloaded and loaded conditions, and wherein said first and second resilient seal members are sequentially deployed from said preloaded condition to said loaded condition in response to axial movement of said barrier member relative to said shaft; and f) said second resilient seal member is deployed into sealing engagement with said shaft in response to a failure of said first resilient sealing element to maintain sealing engagement with said shaft, and wherein said first resilient sealing element effects a partial seal relative to said shaft notwithstanding said failure to maintain sealing engagement with said shaft.