Methods and devices for safely penetrating materials

A tool insertion device comprising:

• a bi-stable coupling connecting an input drive member to a tool
• wherein the bi-stable coupling having at least two positions;
• in a first position, the bi-stable coupling resists a reactive force applied along the longitudinal axis applied to the drill chuck;
• and
• in a second position, the bi-stable coupling collapses upon the removal of a reactive force applied to the tool along the longitudinal axis of the device;
• and
• wherein the bi-stable coupling extends along the longitudinal axis having a first length while in the first position and a second, shorter length while in the second position.

A tool insertion device comprising:

• a bi-stable coupling connecting an input drive member to a tool, the bi-stable coupling comprising a first linkage and a second linkage;
• wherein the bi-stable coupling having at least two positions;
• in a first position, the bi-stable coupling resists a reactive force applied along the longitudinal axis applied to the drill chuck;
• and
• in a second position, the bi-stable coupling collapses upon the removal of a reactive force applied to the tool along the longitudinal axis of the device.