US Patent 7513722 Collet collar stop for a drill bit

A stop for a drill bit having a shaft, the stop having a first member which includes a collet. The collet is configured to receive the shaft of the drill bit and is positionable along the shaft of the drill bit. The stop also has a second member which includes a clamp, for clamping the first member in a desired position along the shaft of the drill bit by securing the collet in a desired position along the shaft of the drill bit. The stop further has an abutment surface on one of the first and second members, for limiting the depth of penetration of the drill bit into an object, the abutment surface being disposed in a fixed position along the shaft of the drill bit by the clamping of the first and second members.