Boring unit

A boring unit comprising:

• a rotatably driven spindle,
• a tool support mounted in a bore of said spindle for rotation about an axis of adjustment extending perpendicular to the axis of rotation and including:
• a front recess for receiving a boring tool,
• a rearwardly extending headbolt, and
• a rearwardly extending supporting arm,
• an adjustment member including an inclined wedge surface means engaging said support arm,
• a movable connecting rod operably connected to said adjusting member for moving the same longitudinally so that said wedge surface means imparts rotary movement to said supporting arm and said tool support about said axis of adjustment;
• a chucking cage containing a plurality of balls between which is received a rear portion of said headbolt to secure said tool support, said cage being longitudinally slidable within a bore of said supporting arm such that said balls are engageable with an inclined wall of said supporting arm and thereupon move away from said bolt to release same and permit removal of said tool support,
• spring means for urging said cage in a direction relative to said inclined wall for maintaining said tool support secured,
• said connecting rod being arranged such that continued movement thereof beyond its stroke for rotating said tool support causes said connecting rod to contact and shift said cage longitudinally against the bias of said spring means to release said tool support.