Collet stop

A work piece positioning mechanism comprising:

• a collet having a cylindrical body and a flared outer end;
• said collet having a cylindrical bore passing there through and a plurality of longitudinal slots passing traversely through the said flared outer end whereby a work piece may be positioned within said bore a predetermined distance from the outer flared end;
• a work piece stop mechanism comprising a cylindrical body having external threads at the outer end thereof to secure to the inner end of said collet and a conical inner surface at the outer end thereof;
• a cylindrical locking collet received within said body having an outer conical surface adapted to engage the said inner conical surface of the body;
• said locking collet having a plurality of longitudinal slots passing traversely therethrough toward the outer end thereof;
• the inner end of said locking collet being externally threaded;
• a locking nut threaded to the inner end of the locking collet and abutting the inner end of said body;
• stop rod means slidably located within a cylindrical bore passing through said locking collet and being adapted to be axially positioned at a predetermined location within said collet;
• said body conical surface and said locking collet conical surface cooperating upon rotation of the locking nut to selectively compress and release the outer end of the locking collet to selectively grip and release said stop rod means;
• said body conical surface and said locking collet conical surface each having an angle with respect to the axis of the stop mechanism within the range of 20 to 45 degrees.