Patent ID: 6305753
Filing Date: 2001-10-23
Classification: E21C

Abstract:
An expander, comprising:a support shaft;a pair of sleeves disposed about on said support shaft proximate either end of said support shaft;an expandable tube disposed about said support shaft and said sleeves;a pair of end caps proximate said either end of said support shaft surrounding said expandable tube such that, proximate each end of said support shaft, one of said end caps and one of said sleeves pinch said expandable tube;a port for porting hydraulic fluid between said support shaft and said expandable tube;a pair of expandable sheaths disposed about said expandable tube at each of said end caps, each of said sheathes capable of minimizing expansion of said expandable tube over one of said end caps, wherein each of said end caps overlaps an end of one of said sheaths; anda bleed for bleeding air from between said support shaft and said expandable tube.