Power Tool Adjustment Device

Author:  Paul E. Troike
Source:  US Patent 3,451,490
Doc ID:  1967035
Year of Publication:  1967
Abstract:  
A power tool attachment which controls the depth of penetration or exposure of the power instrument, such as a drill or the like. Two concentric cylinders having coincident longitudinal slots are fitted over a knob projecting out from the instrument end of the power tool. The longer inner concentric cylinder is biased away from the power tool whereas the shorter outer concentric cylinder is rotated to any of a number of stepwise notches which engage the knob on the tool. The inner cylinder is flanged to engage the outer cylinder so that the cylinders coact to hold the inner cylinder in a precisely positioned relationship with the power instrument.