Patent ID: 6098714
Filing Date: 2000-08-08
Classification: E21B,F15B

Abstract:
An improved fluid actuator comprising:a variable volume fluid chamber;a first tube fixed within the variable volume fluid chamber, the first tube comprising a first sealing surface and a second sealing surface disposed on an outer surface of the first tube;a piston having a first and a second sealing surface, the piston slidably disposed within the variable volume fluid chamber and slidably disposed over the first tube between a first position and a second position;wherein the piston first sealing surface and the first tube first sealing surface cooperate to form a seal between the piston and the first tube when the piston is in the first position; andwherein the piston second sealing surface and the first tube second sealing surface cooperate to form a seal between the piston and the first tube when the piston is in the second position.