Patent ID: 7398736

Claim:
A vehicle for traveling along a conduit having fluid flowing therein, the vehicle comprising: at least one first body portion; a plurality of first retractable resilient members mounted to said body portion and adapted to engage an internal wall of a conduit such that said first resilient members resist movement of the vehicle along a conduit in a first direction more than in a second direction opposite to said first direction; a plurality of second retractable resilient members mounted to said body portion and adapted to engage the internal wall of the conduit such that said second resilient members resist movement of the vehicle along the conduit in said second direction more than in said first direction; at least one second body portion having a respective plurality of third resilient members adapted to engage the internal wall of the conduit such that said third resilient members resist movement of the second body portion relative to the conduit in one of said first or second direction more than in the other of said first or second direction; and at least one moving device for moving said first body portion and the or each said second body portion towards and away from each other; wherein said first and second resilient members are stiffer than said third resilient members.