Quick change chuck assembly for tool bits

A quick change chuck assembly for tool bits having a shank with a plurality of sides, the sides separated by a plurality of edges, and a groove with a radiused portion extending circumferentially about the shank, the chuck assembly comprising:

• a spindle having a forward face;
• a longitudinal bore into the spindle from the forward face having an inner wall for receiving the shank of the tool bit;
• a first segment of the inner wall, the first segment having a first end and a second end, the first end adjacent the forward face, the first segment having a plurality of splines extending longitudinally along the bore for engaging the shank;
• a second segment of the inner wall, the second segment having a first end and a second end, the first end of the second segment adjacent to the second end of the first segment, the second segment having a radially inwardly extending shoulder for receiving the shank, the shoulder having a plurality of faces, the number of faces less than or equal to the number of edges of the shank;
• a third segment of the inner wall, the third segment having a first end and a second end, the first end of the third segment adjacent to the second end of the second segment, the second end of the third segment having an end stop positioned within the bore;
• wherein the shank may be inserted into the longitudinal bore through the first and second segments and into the third segment such that the groove of the shank is aligned with the shoulder of the second segment and a base of the shank is adjacent the end stop in the third segment;
• and
• wherein the shank may be rotated such that a lower edge of the shank between the groove and the base is positioned securely between a face of the shoulder and the end stop, thereby locking the shank of the tool bit in position and preventing longitudinal movement of the tool bit within the longitudinal bore.