Patent ID: 7172377

Claim:
An extension for use between a bit and a power tool comprising: a. a body having a longitudinal axis, a bit receiving end, and an opposite end adapted to be operatively connected to a power tool; b. the body having a first space extending from an opening in the bit receiving end inwardly along the longitudinal axis for slidably receiving the shank of a bit; c. a second space entering the body and intersecting with said first space; d. a threaded bore in the body; e. a clamping member slidably insertable into the second space and moveable such that a portion of the clamping member enters the first space to clamp a bit f. the clamping member comprising; i. a shoulder bolt having a head of a diameter, a shoulder of a diameter smaller than the head, and a shaft with a smaller diameter than the shoulder, a portion of the shaft being threaded for mating insertion into the threaded bore in the body; ii. a sleeve having a longitudinal axis and a through bore between opposite ends along the longitudinal axis for mating, slidable insertion over the shoulder of the bolt; iii. so that the shoulder provides a bearing surface for the sleeve larger than the threaded shaft, a surface of the sleeve can be pulled into the first space for clamping by turning the shoulder bolt into the threaded bore in the body, and the sleeve is not eccentric to the bore through it.