Patent ID: 7448591

Claim:
A step ratchet mechanism adapted for moving a mandrel in a first direction and moving said mandrel in a second direction opposite of said movement in a first direction; said step ratchet mechanism comprising: a. a mandrel with an outer diameter and an outer surface; b. a top connector with a proximal and distal end and an inner diameter greater than the outer diameter of said mandrel, said top connector surrounding said mandrel thereby creating a chamber between said top connector and said mandrel; c. an upper adapter connected to the proximal end of said top connector and adjacent to said mandrel, said upper adapter having a port in fluid communication with said chamber; d. a lower adapter connected to the distal end of said top connector and adjacent to said mandrel, said lower adapter having a port in fluid communication with said chamber; e. a moveable piston located within said chamber adjacent to said top connector and said mandrel, said moveable piston adapted to substantially prevent fluid communication between the port in said upper adapter and the port in said lower adapter through said chamber; f. a locking mechanism having an inner and outer surface, said inner surface of said locking mechanism adapted to selectively engage said mandrel; g. a locking mechanism carrier having an inner and outer surface, said inner surface of said locking mechanism carrier adapted to selectively engage the outer surface of said locking mechanism; and h. a spring located within a spring holder.