Exchange chuck for a tool

An exchange chuck for a tool such as a drill, said tool including a tool shank which may be extractably introduced into the chuck and which has a shank portion with first and second ends and an exchange inhibit groove proximate the first end of the shank portion, said chuck comprising;

• a spindle having a tubular portion with a mounting bore in which the shank portion may be introduced;
• a connecting means provided to the second end of said shank portion and said tubular portion and operable upon insertion of said shank portion into said mounting bore to cause rotation of said tool shank in unison with said spindle;
• ejector means in the form of a roofed cylinder received in a bottom end of said mounting bore and being adapted to eject said tool shank, said ejector means having an annular groove formed on the outer peripheral edge of said cylinder and an engaging step formed at one end of said annular groove;
• a coil spring interposed between the roof of said cylinder and the bottom end of said mounting bore for perpetually biasing said ejector means in a first longitudinal direction;
• at least one ball mounted in said tubular portion;
• and
• a movable sleeve received on said tubular portion for movement longitudinally thereof, said sleeve having an undercut annular groove formed on the inner periphery of said movable sleeve and said undercut annular groove including cam means on one end thereof, said sleeve being adapted through longitudinal movement to cause said ball to be moved radially into said mounting bore between first and second positions, said ball being operative when intruded into said mounting bore in said first position to engage with the extraction inhibit groove of said tool shank to inhibit extraction of said tool shank and operative when intruded into said mounting bore in said second position upon removal of the tool shank to engage said engaging step of said annular groove in said ejector means to inhibit extraction of said ejector means in said first longitudinal direction.