Patent ID: 8794104

Claim:
A thermal ratchet system, comprising: a ratchet housing defining a first locking profile and a second locking profile; a ratchet mandrel; a first ratchet defining a locking profile operably associated with the first locking profile of the ratchet housing and disposed at a position generally fixed with respect to the ratchet housing and urgeable with respect to the ratchet mandrel in an axial direction by a change in environmental temperature in a first direction; and a second ratchet defining a locking profile operably associated with the second locking profile of the ratchet housing and disposed at a position generally fixed with respect to the ratchet housing and urgeable with respect to the ratchet mandrel in the axial direction by a change in environmental temperature in a second direction opposite to the first direction; wherein at least one of the first ratchet and the second ratchet is engaged with the ratchet mandrel.