Rotary power tool with expanded collet range

A power tool having a collet assembly for securing a wider variety of tool shanks, comprising:

• a tool body having an output spindle with a threaded distal end, a collet receiving bore in the distal end of the spindle, a collet received in the bore having a distal end with a plurality of radially expandable and contractable jaw portions, and a proximal shank end with a plurality of radially expandable and contractable shank portions, first cam means on the distal end of the spindle for engaging and camming the jaw portions, a collet nut threadedly engaging the spindle distal end and having a second cam means for engaging and camming the jaw portions, and means to enable a greater range of radial movement of the jaw portions to secure a wider range of shank diameters including a radial chamber in the spindle collet bore adjacent the collet shank portions to enable the collet shank portions to expand into the chamber as the collet jaw portions are cammed against larger tool shanks, said collet being a one-piece member having a central bore therethrough with a plurality of communicating radial slots extending through the jaw portions and the shank portions, said central bore in the collet being tapered from the distal end of the jaw portions to the proximal end of the jaw portions to permit larger diameter tool shanks to engage the inner surfaces of the jaw portions and spread the jaw portions as the larger diameter tool shanks are inserted into the collet, said collet nut having a hollow interior portion of sufficient diameter to enable the jaw portions to expand as the larger diameter shanks spread the jaw portions upon tool shank insertion.

A power tool having a collet assembly for securing a wider variety of tool shanks, comprising:

• a tool body having an output spindle with a threaded distal end, a collet receiving bore in the distal end of the spindle, a collet received in the bore having a distal end with a plurality of radially expandable and contractable jaw portions, and a proximal shank end with a plurality of radially expandable and contractable shank portions, first cam means on the distal end of the spindle for engaging and camming the jaw portions, said first cam means being integral with and formed directly on the end of the spindle, a collet nut threadedly engaging the spindle distal end and having a second cam means for engaging and camming the jaw portions, and means to accommodate larger diameter tool shanks including a central bore through the collet with a plurality of communicating radial slots extending through the jaw portions and the shank portions, said central bore in the collet being tapered from the distal end of the jaw portions to the proximal end of the jaw portions to permit larger diameter tool shanks to engage the inner surfaces of the jaw portions and spread the jaw portions as the larger diameter tool shanks are inserted into the collet, said collet nut having a hollow interior portion of sufficient diameter to enable the jaw portions to expand as the larger diameter shanks spread the jaw portions upon bit insertion.