Dual Size Tool-Bit Holder

A tool-bit holder for varying tool-bit shank profiles, the tool-bit holder comprising:

• a hub having a longitudinal bore having an open end, the longitudinal bore having a first section having a first non-circular profile and a first length, and the longitudinal bore having a second section having a second non-circular profile and second length, the second profile of a smaller area than the first profile, and the hub having at least one radial slots communicating with the first section of the longitudinal bore;
• a collar fixedly attached to the hub adjacent the open end of the longitudinal bore and disposed annularly about the hub wherein a proximal end of the collar forms a channel over the radial slot;
• a sleeve axially slidably mounted along the hub and disposed annularly about the hub wherein the sleeve is at least partially within the channel and at least one radial bores, the radial bore of the sleeve being in communication with the radial slots of the hub;
• a shank engaging element disposed within the radial bores of the sleeve and the radial slot of the hub and the channel of the collar;
• at least one inner ramp face on the proximal end of the collar for engaging the shank engaging element wherein the inner ramp face extends radially outwardly and away from the open end of the longitudinal bore;
• and
• a spring biasing the sleeve towards the open end of the longitudinal bore wherein the shank engaging element in the radial bores of the sleeve engages the inner ramp face and the sleeve is slidably positionable along the hub between a locking position and a retracting position;
• wherein contact between a tool-bit shank having the second profile and the shank engaging element urges the shank engaging element radially outwardly against the at least one inner ramp face to a first extent and wherein contact between a tool-bit shank having the first profile and the shank engaging element urges the shank engaging element radially outwardly against the at least one inner ramp face to a second extent that is greater than the first extent.