Threading attachment for automatic lathes

A lathe attachment including a pair of quills contained within a rocking tailstock, the first one adapted to hold a drill bit or other cutting tool and the second adapted to hold a threading bit, the quills being movable to and from their working positions, a spindle for a work piece and a driving shaft, characterised in that the driving shaft being rotatable at a rate proportional to the rate of rotation of the spindle;

• and being adapted to drive a camshaft contained within the rocking tailstock when the quill holding the drill bit has reached a predetermined rearward position disengaged from the work piece, the driving shaft including clutch means to engage the second quill to rotate it at a speed slower than that of the work piece spindle, the rate of advance being determined by an adjuster element, the camshaft including means to increase the rate of rotation to a value greater than that of the work piece spindle in order to screw the threading bit out of the work piece, and means to return the first quill to its working position once the threading operation is complete.