Mechanical stepper

A mechanical stepper, comprising:

• a housing having a cavity on an inner diameter surface;
• a stepper sleeve within the cavity, the stepper sleeve including a first stop member having an equilibrium position defined by a first equilibrium diameter and a second stop member having an equilibrium position defined by a second equilibrium diameter less than the first equilibrium diameter;
• and
• an insert within the housing and movable with respect to the housing, the insert including a protrusion;
• wherein the insert moves incrementally through the housing via interaction between the protrusion on the insert and the first stop member and the second stop member.

A mechanical stepper, comprising:

• a housing having a protrusion on an inner diameter surface;
• an insert within the housing and movable with respect to the housing, the insert including a cavity on its outer surface;
• and
• a stepper sleeve within the cavity, the stepper sleeve including a first stop member having an equilibrium position defined by a first equilibrium diameter and a second stop member having an equilibrium position defined by a second equilibrium diameter greater than the first equilibrium diameter;
• wherein the insert moves incrementally through the housing via interaction between the protrusion on the housing and the first stop member and the second stop member.